JP5248182B2 - Force detection device - Google Patents

Description

  The present invention relates to a force detection device, and more particularly, to a force detection device suitable for detecting force and moment independently.

  Various types of force detection devices are used to control the operation of robots and industrial machines. Also, a small force detection device is incorporated as a man-machine interface of an input device of an electronic device. In order to reduce the size and reduce the cost, the force detection device used for such an application has a simple structure as much as possible and can independently detect forces related to each coordinate axis in a three-dimensional space. Is required.

  In general, the detection target of the force detection device includes a force component directed in a predetermined coordinate axis direction and a moment component around the predetermined coordinate axis. When the XYZ three-dimensional coordinate system is defined in the three-dimensional space, the detection target is six components including force components Fx, Fy, Fz in the respective coordinate axis directions and moment components Mx, My, Mz around the respective coordinate axes. .

As a force detection device capable of detecting each of these six force components independently, for example, Patent Document 1 below discloses a device having a relatively simple structure. The technique disclosed in Patent Document 1 is a technique to which US Pat. No. 6,915,709, US Pat. No. 7,121,147, and European Patent No. 1464939 are already provided, and a force receiving body and a support substrate are provided with a plurality of columnar bodies. The components connected in the above are prepared, and each component of the force applied to the force receiving body is detected by individually measuring the pressing force applied to the support substrate from each columnar body and the inclination of each columnar body. The technique disclosed in Patent Document 2 below is also a technique to which US Pat. No. 7,219,561 has already been granted. According to this technology, a capacitive element is used as a sensor for individually measuring the pressing force applied to the support substrate from each columnar body and the inclination of each columnar body, and wiring is performed between specific electrodes constituting this capacitive element. By applying the above, it is possible to simplify the calculation for detecting each component of the force applied to the force receiving body.
JP 2004-354049 A JP 2004-325367 A

  As described above, the force detection devices disclosed in Patent Documents 1 and 2 have force components Fx, Fy, and Fz in the direction of each coordinate axis and moment components Mx, My, and Mz around each coordinate axis by a relatively simple structure. 6 components can be detected independently of each other. However, in practice, it is difficult to obtain accurate measurement values of only the necessary components with the interference of other axis components completely eliminated, and a decrease in measurement accuracy due to interference of other axis components is inevitable. . Of course, there is no problem as long as the interference of other axis components is within an allowable error range according to each application, but recently, a force detection device with higher measurement accuracy is desired in various fields of use. It is rare.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a force detection device that has a simple structure as much as possible, eliminates interference of other axis components, and can detect force and moment separately.

(1) A first aspect of the present invention includes a support substrate, a force receiving body disposed above the support substrate, a first columnar body for connecting the support substrate and the power receiving body, and a support A force detection device that detects a force acting on the force receiving member in a state where the support substrate is fixed, and a second columnar body for connecting the substrate and the force receiving member;
The upper end of the first columnar body is connected to the force receiving body via a flexible member, and the lower end of the first columnar body is connected to the support substrate via a flexible member. ,
The upper end of the second columnar body is connected to the power receiving body via a flexible member, and the lower end of the second columnar body is connected to the support substrate via a flexible member. ,
The XY plane is positioned on or above the upper surface of the support substrate so as to be parallel to the upper surface of the support substrate. Thus, when the XYZ three-dimensional coordinate system is defined,
The first columnar body is arranged at a position where the central axis is parallel to the Z axis and the central axis intersects the positive part of the X axis,
The second columnar body is arranged such that its central axis is parallel to the Z axis and its central axis intersects the negative part of the X axis,
A detector that is disposed near the lower end of the first columnar body and detects the inclination of the first columnar body in the X-axis direction, and a force in the Z-axis direction that is applied to the support substrate from the entire first columnar body. A first sensor having a detector for detecting
A detector that is disposed near the lower end of the second columnar body and detects the inclination of the second columnar body in the X-axis direction, and a force in the Z-axis direction that is applied to the support substrate from the entire second columnar body. A second sensor having a detector for detecting
A detection circuit that performs processing for obtaining an X-axis direction component Fx of the force acting on the force receiving body based on the detection result of the first sensor and the detection result of the second sensor, and outputting the same;
Further provided,
The detection circuit
An arithmetic function for obtaining a sum Fx ^* of the inclination of the first columnar body in the X-axis direction and the inclination of the second columnar body in the X-axis direction;
A calculation function for obtaining a difference My between the force in the Z-axis direction applied by the first columnar body and the force in the Z-axis direction applied by the second columnar body;
An arithmetic function for obtaining an X-axis direction component Fx of the force acting on the force receiving body based on an arithmetic expression “Fx = Fx ^* −α · My” using a predetermined coefficient α;
And have
The coefficient α is an expression “α = Fx ^* (0) / using the value Fx ^* (0) of the sum Fx ^* and the value My (0) of the difference My obtained in an environment where only the moment about the Y-axis acts. This is set to a value given by “My (0)”.

(2) According to a second aspect of the present invention, in the force detection device according to the first aspect described above,
The detection circuit performs processing for outputting the obtained difference My as a moment component around the Y axis of the force acting on the force receiving body.

(3) According to a third aspect of the present invention, in the force detection device according to the first or second aspect described above,
The detection circuit further has a calculation function for obtaining a sum Fz of the force in the Z-axis direction applied by the first columnar body and the force in the Z-axis direction applied by the second columnar body, and the obtained sum Fz Is output as a Z-axis direction component of the force acting on the force receiving body.

(4) According to a fourth aspect of the present invention, in the force detection device according to the first to third aspects described above,
Detection in which the first sensor further includes a detector that detects the inclination of the first columnar body in the Y-axis direction, and the second sensor detects the inclination of the second columnar body in the Y-axis direction. Have a child,
The detection circuit further has a calculation function for obtaining a difference Mz between the inclination of the first columnar body in the Y-axis direction and the inclination of the second columnar body in the Y-axis direction. A process for outputting the force acting on the body as a moment component around the Z-axis is performed.

(5) According to a fifth aspect of the present invention, in the force detection device according to the first to fourth aspects described above,
The upper end side thin portion having flexibility is connected to the upper end of each columnar body, the upper end side thin portion is connected to the power receiving body around the upper end side thin portion, and the lower surface center portion is the upper end of the columnar body. Connected to
A flexible lower end side thin portion is connected to the lower end of each columnar body, and the lower end side thin portion is located above the upper surface of the support substrate at a predetermined distance from the upper surface of the support substrate. The periphery of the columnar body is connected to the support substrate through the pedestal, and the center of the upper surface is connected to the lower end of the columnar body.

(6) According to a sixth aspect of the present invention, in the force detection device according to the fifth aspect described above,
For each columnar body, an xy two-dimensional local coordinate having an origin at the intersection of the central axis of the columnar body and the upper surface of the support substrate, an x-axis parallel to the X-axis, and a y-axis parallel to the Y-axis When defining a system,
As a detector for detecting the inclination of the columnar body in the X-axis direction,
A first electrode formed in a region where the x-coordinate value is positive on the upper surface of the support substrate; and a first counter electrode formed in a position facing the first electrode on the lower surface of the lower end side thin portion; A first capacitive element constituted by:
A second electrode formed in a region where the x-coordinate value is negative on the upper surface of the support substrate; and a second counter electrode formed at a position facing the second electrode on the lower surface of the lower end side thin portion; A second capacitive element constituted by:
And a detector for obtaining a difference between the capacitance value C1 of the first capacitive element and the capacitance value C2 of the second capacitive element as an inclination in the X-axis direction of the columnar body is used.
When a detector that detects the inclination of the columnar body in the Y-axis direction is necessary,
A third electrode formed in a region where the y coordinate value is positive on the upper surface of the support substrate; and a third counter electrode formed at a position facing the third electrode on the lower surface of the lower end side thin portion; A third capacitive element constituted by:
A fourth electrode formed in a region where the y-coordinate value is negative on the upper surface of the support substrate; and a fourth counter electrode formed in a position facing the fourth electrode on the lower surface of the lower end side thin portion; A fourth capacitive element constituted by:
And a detector for determining the difference between the capacitance value C3 of the third capacitive element and the capacitance value C4 of the fourth capacitive element as the inclination in the Y-axis direction of the columnar body is used.
As a detector for detecting the force in the Z-axis direction applied to the support substrate from the entire columnar body,
A fifth capacitive element configured by a fifth electrode formed on the upper surface of the support substrate and a fifth counter electrode formed at a position facing the fifth electrode on the lower surface of the thin portion on the lower end side. And a detector for determining the capacitance value C5 of the fifth capacitive element as a force in the Z-axis direction applied to the support substrate from the entire columnar body,
Each of the first electrode itself and the second electrode itself has a shape that is line-symmetric with respect to the x-axis, and an electrode group that includes the first electrode and the second electrode is line-symmetrical with respect to the y-axis. Has a shape that
Each of the third electrode and the fourth electrode itself has a shape that is line-symmetric with respect to the y-axis, and an electrode group that includes the third electrode and the fourth electrode is line-symmetric with respect to the x-axis. Has a shape that
The fifth electrode itself has a shape that is line-symmetric with respect to both the x-axis and the y-axis.

(7) According to a seventh aspect of the present invention, there is provided a support substrate, a force receiving body disposed above the support substrate, a first columnar body for connecting the support substrate and the force receiving body, and a support A second columnar body for connecting the substrate and the force receiving body; a third columnar body for connecting the support substrate and the power receiving body; and a second columnar body for connecting the support substrate and the power receiving body. A force detection device that detects a force acting on a force receiving body in a state where the support substrate is fixed.
The upper end of the first columnar body is connected to the force receiving body via a flexible member, and the lower end of the first columnar body is connected to the support substrate via a flexible member. ,
The upper end of the second columnar body is connected to the power receiving body via a flexible member, and the lower end of the second columnar body is connected to the support substrate via a flexible member. ,
The upper end of the third columnar body is connected to the force receiving body via a flexible member, and the lower end of the third columnar body is connected to the support substrate via a flexible member. ,
The upper end of the fourth columnar body is connected to the force receiving body via a flexible member, and the lower end of the fourth columnar body is connected to the support substrate via a flexible member. And
The XY plane is positioned on or above the upper surface of the support substrate so as to be parallel to the upper surface of the support substrate. Thus, when the XYZ three-dimensional coordinate system is defined,
The first columnar body is arranged at a position where the central axis is parallel to the Z axis and the central axis intersects the positive part of the X axis,
The second columnar body is disposed at a position where the central axis is parallel to the Z axis and the central axis intersects the negative part of the X axis.
The third columnar body is arranged at a position where the central axis is parallel to the Z axis and the central axis intersects the positive part of the Y axis,
The fourth columnar body is arranged such that its central axis is parallel to the Z axis and its central axis intersects the negative part of the Y axis,
A detector that is disposed in the vicinity of the lower end of the first columnar body and detects the inclination of the first columnar body in the X-axis direction; and a detector that detects the inclination of the first columnar body in the Y-axis direction; A first sensor having a detector for detecting a force in the Z-axis direction applied to the support substrate from the entire first columnar body;
A detector that is disposed near the lower end of the second columnar body and detects the inclination of the second columnar body in the X-axis direction; and a detector that detects the inclination of the second columnar body in the Y-axis direction; A second sensor having a detector for detecting a force in the Z-axis direction applied to the support substrate from the entire second columnar body;
A detector that is disposed near the lower end of the third columnar body and detects the inclination of the third columnar body in the X-axis direction; and a detector that detects the inclination of the third columnar body in the Y-axis direction; A third sensor having a detector for detecting a force in the Z-axis direction applied to the support substrate from the entire third columnar body;
A detector that is arranged near the lower end of the fourth columnar body and detects the inclination of the fourth columnar body in the X-axis direction; and a detector that detects the inclination of the fourth columnar body in the Y-axis direction; A detector for detecting a force in the Z-axis direction applied to the support substrate from the entire fourth columnar body, and a fourth sensor having
Based on the detection result of the first sensor, the detection result of the second sensor, the detection result of the third sensor, and the detection result of the fourth sensor, the X-axis direction component Fx of the force acting on the force receiving body And a detection circuit that performs processing for obtaining the Y-axis direction component Fy and outputting these components,
Further provided,
The detection circuit
“The degree of inclination of the first columnar body in the X-axis direction, the degree of inclination of the second columnar body in the X-axis direction, the degree of inclination of the third columnar body in the X-axis direction, and the X-axis direction of the fourth columnar body. "Fx1 ^* " with the inclination, or "Fx2 ^* with the inclination of the first columnar body in the X-axis direction and the inclination of the second columnar body in the X-axis direction" or "X of the third columnar body An arithmetic function for calculating any one of the sums Fx3 ^* of the inclination with respect to the axial direction and the inclination with respect to the X-axis direction of the fourth columnar body as a sum Fx ^* ;
“The inclination of the first columnar body in the Y-axis direction, the inclination of the second columnar body in the Y-axis direction, the inclination of the third columnar body in the Y-axis direction, and the Y-axis direction of the fourth columnar body. Y sum Fy1 ^* "or" the sum of the inclination and the inclination about the Y-axis direction of the second columnar member in the Y-axis direction of the first columnar body Fy2 ^* "or" the third columnar body of the slope An arithmetic function for calculating any one of the sums Fy3 ^* of the inclination in the axial direction and the inclination in the Y-axis direction of the fourth columnar body as the sum Fy ^* ;
A calculation function for obtaining a difference My between the force in the Z-axis direction applied by the first columnar body and the force in the Z-axis direction applied by the second columnar body;
A calculation function for obtaining a difference Mx between a force in the Z-axis direction applied by the third columnar body and a force in the Z-axis direction applied by the fourth columnar body;
An arithmetic function for obtaining an X-axis direction component Fx of the force acting on the force receiving body based on an arithmetic expression “Fx = Fx ^* −α · My” using a predetermined coefficient α;
An arithmetic function for obtaining a Y-axis direction component Fy of a force acting on the force receiving body based on an arithmetic expression “Fy = Fy ^* + β · Mx” using a predetermined coefficient β;
Have
The coefficient α is an expression “α = Fx ^* (0) / using the value Fx ^* (0) of the sum Fx ^* and the value My (0) of the difference My obtained in an environment where only the moment about the Y-axis acts. Set to the value given by “My (0)”,
Coefficient beta is only moment about the X axis is the sum Fy ^* that is obtained in an environment which acts value ^Fy * (0) and the formula using a difference Mx value Mx (0) "β = ^-Fy * (0) / Mx (0) "is set to a value given.

(8) According to an eighth aspect of the present invention, in the force detection device according to the seventh aspect described above,
The detection circuit outputs the obtained difference My as a moment component around the Y axis of the force acting on the force receiving body, and outputs the obtained difference Mx as a moment component around the X axis of the force acting on the force receiving body. The processing to be performed is performed.

(9) According to a ninth aspect of the present invention, in the force detection device according to the seventh or eighth aspect described above,
The detection circuit includes a force in the Z-axis direction applied by the first columnar body, a force in the Z-axis direction applied by the second columnar body, a force in the Z-axis direction applied by the third columnar body, and the first 4 further includes a calculation function for obtaining a sum Fz with the force in the Z-axis direction applied by the four columnar bodies, and outputting the obtained sum Fz as a Z-axis direction component Fz of the force acting on the force receiving body. It is what I do.

(10) According to a tenth aspect of the present invention, in the force detection device according to the seventh to ninth aspects described above,
The detection circuit detects that the sum of the slope of the first columnar body in the Y-axis direction and the slope of the fourth columnar body in the X-axis direction, the slope of the second columnar body in the Y-axis direction, and the third The difference Mz1 between the sum of the inclination of the columnar body in the X-axis direction and the difference Mz2 between the inclination of the first columnar body in the Y-axis direction and the inclination of the second columnar body in the Y-axis direction. Or “the difference Mz3 between the inclination of the fourth columnar body in the X-axis direction and the inclination of the third columnar body in the X-axis direction” as the difference Mz. A process of outputting the difference Mz as a moment component around the Z-axis of the force acting on the force receiving body is performed.

(11) An eleventh aspect of the present invention is the force detection device according to the seventh to tenth aspects described above,
The upper end side thin portion having flexibility is connected to the upper end of each columnar body, the upper end side thin portion is connected to the power receiving body around the upper end side thin portion, and the lower surface center portion is the upper end of the columnar body. Connected to
A flexible lower end side thin portion is connected to the lower end of each columnar body, and the lower end side thin portion is located above the upper surface of the support substrate at a predetermined distance from the upper surface of the support substrate. The periphery of the columnar body is connected to the support substrate through the pedestal, and the center of the upper surface is connected to the lower end of the columnar body.

(12) A twelfth aspect of the present invention is the force detection device according to the eleventh aspect described above,
For each columnar body, an xy two-dimensional local coordinate having an origin at the intersection of the central axis of the columnar body and the upper surface of the support substrate, an x-axis parallel to the X-axis, and a y-axis parallel to the Y-axis When defining a system,
As a detector for detecting the inclination of the columnar body in the X-axis direction,
A first electrode formed in a region where the x-coordinate value is positive on the upper surface of the support substrate; and a first counter electrode formed in a position facing the first electrode on the lower surface of the lower end side thin portion; A first capacitive element constituted by:
A second electrode formed in a region where the x-coordinate value is negative on the upper surface of the support substrate; and a second counter electrode formed at a position facing the second electrode on the lower surface of the lower end side thin portion; A second capacitive element constituted by:
And a detector for obtaining a difference between the capacitance value C1 of the first capacitive element and the capacitance value C2 of the second capacitive element as an inclination in the X-axis direction of the columnar body is used.
As a detector for detecting the inclination of the columnar body in the Y-axis direction,
A third electrode formed in a region where the y coordinate value is positive on the upper surface of the support substrate; and a third counter electrode formed at a position facing the third electrode on the lower surface of the lower end side thin portion; A third capacitive element constituted by:
A fourth electrode formed in a region where the y-coordinate value is negative on the upper surface of the support substrate; and a fourth counter electrode formed in a position facing the fourth electrode on the lower surface of the lower end side thin portion; A fourth capacitive element constituted by:
And a detector for determining the difference between the capacitance value C3 of the third capacitive element and the capacitance value C4 of the fourth capacitive element as the inclination in the Y-axis direction of the columnar body is used.
As a detector for detecting the force in the Z-axis direction applied to the support substrate from the entire columnar body,
A fifth capacitive element configured by a fifth electrode formed on the upper surface of the support substrate and a fifth counter electrode formed at a position facing the fifth electrode on the lower surface of the thin portion on the lower end side. And a detector for determining the capacitance value C5 of the fifth capacitive element as a force in the Z-axis direction applied to the support substrate from the entire columnar body,
Each of the first electrode itself and the second electrode itself has a shape that is line-symmetric with respect to the x-axis, and an electrode group that includes the first electrode and the second electrode is line-symmetrical with respect to the y-axis. Has a shape that
Each of the third electrode and the fourth electrode itself has a shape that is line-symmetric with respect to the y-axis, and an electrode group that includes the third electrode and the fourth electrode is line-symmetric with respect to the x-axis. Has a shape that
The fifth electrode itself has a shape that is line-symmetric with respect to both the x-axis and the y-axis.

(13) A thirteenth aspect of the present invention includes a support substrate, a force receiving body disposed above the support substrate, and four columnar bodies for connecting the support substrate and the power receiving body. In a state where the support substrate is fixed, a force detection device that detects the force acting on the force receiving body,
A flexible upper end side thin portion is connected to each upper end of the four columnar bodies, and a flexible lower end side thin portion is connected to each lower end of the four columnar bodies. Is connected,
The upper end side thin part is connected to the power receiving body at the periphery, and the lower surface center part is connected to the upper end of the columnar body,
The lower end side thin portion is connected to the support substrate via a pedestal so that the lower end side thin portion is arranged in parallel to the upper surface of the support substrate at an upper position with a predetermined distance from the upper surface of the support substrate. The part is connected to the lower end of the columnar body,
The XY plane is positioned on or above the upper surface of the support substrate so as to be parallel to the upper surface of the support substrate. Thus, when the XYZ three-dimensional coordinate system is defined,
The four columnar bodies are arranged so that their central axes are parallel to the Z axis, and the first columnar body is arranged at a position where the central axis intersects the positive part of the X axis. The second columnar body is disposed at a position where the central axis intersects the negative portion of the X axis, and the third columnar body is disposed at a position where the central axis intersects the positive portion of the Y axis. The fourth columnar body is disposed at a position where the central axis intersects the negative part of the Y axis,
One electrode is formed on the lower surface of the lower end thin portion, and the other electrode is the upper surface of the support substrate in a space sandwiched between the lower end thin portion of the first columnar body and the upper surface of the support substrate facing the first columnar body. A first sensor composed of a plurality of capacitive elements formed in
One electrode is formed on the lower surface of the lower end thin portion, and the other electrode is the upper surface of the support substrate in a space sandwiched between the lower end thin portion of the second columnar body and the upper surface of the support substrate facing the second columnar body. A second sensor comprising a plurality of capacitive elements formed in
One electrode is formed on the lower surface of the lower end thin portion, and the other electrode is the upper surface of the support substrate in a space sandwiched between the lower end thin portion of the third columnar body and the upper surface of the support substrate facing the third columnar body. A third sensor comprising a plurality of capacitive elements formed in
One electrode is formed on the lower surface of the lower end thin portion and the other electrode is the upper surface of the support substrate in a space sandwiched between the lower end thin portion of the fourth columnar body and the upper surface of the support substrate facing the fourth columnar body. A fourth sensor comprising a plurality of capacitive elements formed in
As a candidate of the capacitive element constituting the first sensor,
When the first columnar body is tilted in the positive direction of the X axis, the capacitance value is increased by narrowing the electrode interval, and when the first columnar body is tilted in the negative direction of the X axis, the electrostatic capacity is increased by increasing the electrode interval. When the capacitance value decreases and the first columnar body inclines in the positive direction of the Y axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the first columnar body is Y A capacitance element C11 formed such that when the electrode is inclined in the negative direction, a part of the electrode interval is narrowed but another part is widened, so that the capacitance value does not change;
When the first columnar body is inclined in the X-axis positive direction, the capacitance value is reduced by increasing the electrode interval, and when the first columnar body is inclined in the X-axis negative direction, the electrode interval is decreased. When the capacitance value increases and the first columnar body inclines in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the first columnar body is Y A capacitive element C12 formed so that a capacitance value does not change by narrowing a part of the electrode interval while expanding another part when tilted in the negative axis direction;
When the first columnar body is tilted in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the first columnar body is tilted in the X-axis negative direction. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value increases by narrowing the electrode spacing when the first columnar body tilts in the positive Y-axis direction. A capacitive element C13 formed such that when the first columnar body is tilted in the negative Y-axis direction, the capacitance value is reduced by increasing the electrode spacing;
When the first columnar body is tilted in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the first columnar body is tilted in the X-axis negative direction. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value decreases by widening the electrode spacing when the first columnar body tilts in the positive Y-axis direction. And a capacitive element C14 formed such that when the first columnar body is inclined in the negative Y-axis direction, the capacitance value increases due to the electrode interval being narrowed;
When the first columnar body is displaced in the Z-axis positive direction, the electrostatic capacity value is reduced by widening the electrode interval, and when the first columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed. When the capacitance value increases and the first columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is narrowed, but another part is widened. A capacitive element C15 formed so that the capacitance value does not change;
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the second sensor,
When the second columnar body is inclined in the positive direction of the X axis, the capacitance value increases due to the electrode interval being narrowed, and when the second columnar body is inclined in the negative direction of the X axis, the electrode interval is increased. When the capacitance value decreases and the second columnar body is inclined in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change, and the second columnar body is Y A capacitive element C21 formed so that a capacitance value does not change by narrowing a part of the electrode spacing while widening another part when tilted in the negative axis direction;
When the second columnar body is inclined in the X-axis positive direction, the capacitance value is reduced by increasing the electrode interval, and when the second columnar body is inclined in the X-axis negative direction, the electrode interval is decreased. When the capacitance value increases and the second columnar body is inclined in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change, and the second columnar body is Y A capacitive element C22 formed so that a capacitance value does not change by narrowing a part of the electrode interval while expanding another part when tilted in the negative axis direction;
When the second columnar body is tilted in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is widened and the capacitance value does not change, and the second columnar body is tilted in the X-axis negative direction. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value increases by narrowing the electrode spacing when the second columnar body tilts in the positive Y-axis direction. A capacitive element C23 formed such that when the second columnar body is inclined in the negative direction of the Y-axis, the capacitance value is reduced by widening the electrode interval;
When the second columnar body is tilted in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is widened and the capacitance value does not change, and the second columnar body is tilted in the X-axis negative direction. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value decreases by widening the electrode spacing when the second columnar body tilts in the positive Y-axis direction. A capacitive element C24 formed such that when the second columnar body inclines in the negative Y-axis direction, the capacitance value increases due to the electrode interval being narrowed;
When the second columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the second columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed to reduce the electrostatic capacity. When the capacitance value increases and the second columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is narrowed, but another part is widened. A capacitive element C25 formed so that the capacitance value does not change;
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the third sensor,
When the third columnar body is inclined in the X-axis positive direction, the capacitance value is increased by narrowing the electrode interval, and when the third columnar body is inclined in the X-axis negative direction, the electrode interval is increased. When the capacitance value decreases and the third columnar body is tilted in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change and the third columnar body is Y A capacitive element C31 formed so that a capacitance value does not change by narrowing a part of the electrode interval but widening another part when tilted in the negative axis direction;
When the third columnar body is inclined in the X-axis positive direction, the capacitance value is reduced by increasing the electrode interval, and when the third columnar body is inclined in the X-axis negative direction, the electrode interval is decreased. When the capacitance value increases and the third columnar body is inclined in the positive direction of the Y axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the third columnar body is Y A capacitive element C32 formed so that a capacitance value does not change by narrowing a part of the electrode interval while expanding another part when tilted in the negative axis direction;
When the third columnar body is inclined in the positive direction of the X axis, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the third columnar body is inclined in the negative direction of the X axis. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value increases by narrowing the electrode spacing when the third columnar body tilts in the positive Y-axis direction. A capacitive element C33 formed such that when the third columnar body is tilted in the negative Y-axis direction, the capacitance value is reduced due to an increase in electrode spacing;
When the third columnar body is inclined in the positive direction of the X axis, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the third columnar body is inclined in the negative direction of the X axis. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value decreases by widening the electrode spacing when the third columnar body tilts in the positive Y-axis direction. A capacitive element C34 formed such that when the third columnar body is inclined in the negative direction of the Y-axis, the capacitance value is increased by reducing the electrode interval;
When the third columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the third columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed to reduce the electrostatic capacity. When the capacitance value increases and the third columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is narrowed, but another part is widened. A capacitive element C35 formed so that the capacitance value does not change;
5 types of capacitive elements are defined,
As a candidate of the capacitive element constituting the fourth sensor,
When the fourth columnar body is inclined in the X-axis positive direction, the capacitance value is increased by narrowing the electrode interval, and when the fourth columnar body is inclined in the X-axis negative direction, the electrode interval is increased. When the capacitance value decreases and the fourth columnar body is inclined in the positive direction of the Y axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change and the fourth columnar body is Y A capacitive element C41 formed so that the capacitance value does not change by narrowing a part of the electrode interval while expanding another part when tilted in the negative axis direction;
When the fourth columnar body is inclined in the X-axis positive direction, the capacitance value is reduced by increasing the electrode interval, and when the fourth columnar body is inclined in the X-axis negative direction, the electrode interval is decreased. When the capacitance value increases and the fourth columnar body tilts in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the fourth columnar body is Y A capacitive element C42 formed so that a capacitance value does not change by narrowing a part of the electrode interval while expanding another part when tilted in the negative axis direction;
When the fourth columnar body is tilted in the positive direction of the X axis, a part of the electrode interval is narrowed, but another part is expanded, so that the capacitance value does not change, and the fourth columnar body is tilted in the negative direction of the X axis. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value increases by narrowing the electrode spacing when the fourth columnar body tilts in the positive Y-axis direction. A capacitive element C43 formed such that when the fourth columnar body is tilted in the negative Y-axis direction, the capacitance value is reduced by increasing the electrode spacing;
When the fourth columnar body is tilted in the positive direction of the X axis, a part of the electrode interval is narrowed, but another part is expanded, so that the capacitance value does not change, and the fourth columnar body is tilted in the negative direction of the X axis. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value decreases by widening the electrode spacing when the fourth columnar body tilts in the positive Y-axis direction. A capacitive element C44 formed such that when the fourth columnar body is inclined in the negative direction of the Y-axis, the capacitance value is increased by narrowing the electrode interval;
When the fourth columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the fourth columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed to reduce the electrostatic capacity. When the capacitance value increases and the fourth columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is narrowed but another part is widened. A capacitive element C45 formed so that the capacitance value does not change;
5 types of capacitive elements are defined,
The X-axis direction component of the force acting on the force receiving body is Fx, the Y-axis direction component is Fy, the Z-axis direction component is Fz, the moment component around the X-axis is Mx, the moment component around the Y-axis is My, and around the Z-axis the moment component and Mz, Fx, the value of the intermediate stage, respectively used in the process of obtaining the Fy Fx ^*, and Fy ^*, and to exhibit capacitance values of the capacitance elements in each same reference numerals of the capacitive elements ,
As a formula for calculating Fx ^* ,
Fx1 ^* = (C11-C12) + (C21-C22) + (C31-C32) + (C41-C42)
Fx2 ^* = (C11-C12) + (C21-C22)
Fx3 ^* = (C31-C32) + (C41-C42)
Define the following three formulas,
As a formula for obtaining Fy ^* ,
Fy1 ^* = (C13-C14) + (C23-C24) + (C33-C34) + (C43-C44)
Fy2 ^* = (C13-C14) + (C23-C24)
Fy3 ^* = (C33-C34) + (C43-C44)
Define the following three formulas,
As an expression for calculating Fz,
Fz1 = − ((C11 + C12 + C13 + C14 + C15) + (C21 + C22 + C23 + C24 + C25) + (C31 + C32 + C33 + C34 + C35) + (C41 + C42 + C43 + C44 + C45))
Fz2 = − ((C11 + C12 + C13 + C14) + (C21 + C22 + C23 + C24) + (C31 + C32 + C33 + C34) + (C41 + C42 + C43 + C44))
Fz3 = − (C15 + C25 + C35 + C45)
Define the following three formulas,
As an expression for obtaining Mx,
Mx1 = (C41 + C42 + C43 + C44 + C45) − (C31 + C32 + C33 + C34 + C35)
Mx2 = (C41 + C42 + C43 + C44)-(C31 + C32 + C33 + C34)
Mx3 = (C45-C35)
Define the following three formulas,
As an expression for calculating My,
My1 = (C11 + C12 + C13 + C14 + C15) − (C21 + C22 + C23 + C24 + C25)
My2 = (C11 + C12 + C13 + C14) − (C21 + C22 + C23 + C24)
My3 = (C15-C25)
Define the following three formulas,
As an expression for obtaining Mz,
Mz1 = ((C13-C14) + (C41-C42))-((C23-C24) + (C31-C32))
Mz2 = (C13-C14)-(C23-C24)
Mz3 = (C41-C42)-(C31-C32)
When defining the following three formulas,
From the candidate capacitive elements,
Fx = Fxi ^* −αij · Myj (where i = 1 to 3, j = 1 to 3)
Fy = Fyi ^* + βij · Mxj (where i = 1 to 3, j = 1 to 3)
Fz = Fzi (where i = 1 to 3)
Mx = Mxi (where i = 1 to 3)
My = Myi (where i = 1 to 3)
Mz = Mzi (where i = 1 to 3)
Capacitance elements necessary for performing an operation based on an expression selected from the following six expressions (however, selection of the Fx expression and the Fy expression is essential) are actually formed, and A detection circuit to perform is provided,
The coefficient αij is an expression “αij = Fxi ^* (0) / Myj () using a value Fxi ^* (0) of Fxi ^{* and} a value Myj (0) of Myj obtained in an environment in which only a moment around the Y-axis acts. 0) "is set to the value given by
The coefficient “βij” is an expression “βij = −Fyi ^* (0) / Mxj using a value Fyi ^* (0) of Fyi ^{* and} a value Mxj (0) of Mxj obtained in an environment in which only a moment around the X axis acts. The value is set to the value given by (0) ".

(14) According to a fourteenth aspect of the present invention, in the force detection device according to the thirteenth aspect described above, instead of the capacitive element candidate described as the thirteenth aspect,
For each columnar body, an xy two-dimensional local coordinate having an origin at the intersection of the central axis of the columnar body and the upper surface of the support substrate, an x-axis parallel to the X-axis, and a y-axis parallel to the Y-axis When defining a system,
As a candidate of the capacitive element constituting the first sensor,
On the upper surface of the support substrate, on the first columnar body x-axis positive side electrode formed in a region where the x coordinate value in the local coordinate system for the first columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C11 formed by a counter electrode formed at a position facing the first columnar x-axis positive electrode;
On the upper surface of the support substrate, on the first columnar body x-axis negative electrode formed in a region where the x coordinate value in the local coordinate system for the first columnar body is negative, and on the lower surface of the lower end side thin portion, A capacitive element C12 constituted by a counter electrode formed at a position facing the first columnar x-axis negative electrode,
On the upper surface of the support substrate, on the first columnar body y-axis positive side electrode formed in a region where the y coordinate value in the local coordinate system for the first columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C13 configured by a counter electrode formed at a position facing the first y-axis positive electrode for the columnar body;
On the upper surface of the support substrate, on the first columnar body y-axis negative electrode formed in a region where the y coordinate value in the local coordinate system for the first columnar body is negative, and on the lower surface of the lower end thin portion, A capacitive element C14 configured by a counter electrode formed at a position facing the first y-axis negative electrode for the columnar body;
On the upper surface of the support substrate, the first columnar body Z-axis displacement detection electrode formed at a predetermined position in the local coordinate system for the first columnar body, and the first columnar body on the lower surface of the lower end side thin portion A capacitive element C15 constituted by a counter electrode formed at a position facing the Z-axis displacement detection electrode for use;
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the second sensor,
On the upper surface of the support substrate, on the lower surface of the second columnar body x-axis positive side electrode formed in the region where the x coordinate value in the local coordinate system of the second columnar body is positive, and the lower end side thin portion, A capacitance element C21 configured by a counter electrode formed at a position facing the second columnar x-axis positive electrode,
On the upper surface of the support substrate, on the second columnar body x-axis negative electrode formed in a region where the x coordinate value in the local coordinate system for the second columnar body is negative, and on the lower surface of the lower end side thin portion, A capacitive element C22 configured by a counter electrode formed at a position facing the second columnar x-axis negative electrode,
On the upper surface of the support substrate, on the second columnar y-axis positive side electrode formed in the region where the y coordinate value in the local coordinate system is positive, and on the lower surface of the lower end thin portion, A capacitive element C23 configured by a counter electrode formed at a position facing the second columnar y-axis positive side electrode;
On the upper surface of the support substrate, on the second columnar body y-axis negative side electrode formed in a region where the y coordinate value in the local coordinate system for the second columnar body is negative, and on the lower surface of the lower end side thin portion, A capacitive element C24 configured by a counter electrode formed at a position facing the second columnar y-axis negative electrode,
On the upper surface of the support substrate, the second columnar body is formed at a predetermined position in the local coordinate system for the second columnar body, and the second columnar body is formed on the lower surface of the lower end side thin portion. A capacitive element C25 constituted by a counter electrode formed at a position facing the Z-axis displacement detection electrode for use;
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the third sensor,
On the upper surface of the support substrate, on the third columnar body x-axis positive side electrode formed in a region where the x coordinate value in the local coordinate system of the third columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C31 constituted by a counter electrode formed at a position facing the third columnar x-axis positive electrode,
On the upper surface of the support substrate, on the third columnar body x-axis negative electrode formed in a region where the x coordinate value in the local coordinate system is negative, and on the lower surface of the lower end thin portion, A capacitive element C32 configured by a counter electrode formed at a position facing the third columnar x-axis negative electrode,
On the upper surface of the support substrate, on the third columnar body y-axis positive side electrode formed in a region where the y coordinate value in the local coordinate system is positive, and on the lower surface of the lower end side thin portion, A capacitive element C33 constituted by a counter electrode formed at a position facing the third columnar y-axis positive electrode,
On the upper surface of the support substrate, on the third columnar body y-axis negative side electrode formed in the region where the y coordinate value in the local coordinate system is negative, and on the lower surface of the lower end thin portion, A capacitive element C34 constituted by a counter electrode formed at a position facing the third columnar y-axis negative electrode,
A third columnar body Z-axis displacement detection electrode formed at a predetermined position in the local coordinate system of the third columnar body on the upper surface of the support substrate and a third columnar body on the lower surface of the lower end side thin portion. A capacitive element C35 constituted by a counter electrode formed at a position facing the Z-axis displacement detection electrode for use;
5 types of capacitive elements are defined,
As a candidate of the capacitive element constituting the fourth sensor,
On the upper surface of the support substrate, on the fourth columnar x-axis positive electrode formed in the region where the x coordinate value in the local coordinate system is positive, and on the lower surface of the lower end thin portion, A capacitive element C41 constituted by a counter electrode formed at a position facing the fourth columnar x-axis positive side electrode;
On the upper surface of the support substrate, on the fourth columnar x-axis negative electrode formed in the region where the x coordinate value in the local coordinate system is negative, and on the lower surface of the lower end side thin portion, A capacitive element C42 constituted by a counter electrode formed at a position facing the fourth columnar x-axis negative electrode,
On the upper surface of the support substrate, on the fourth y-axis positive side electrode for the columnar body formed in the region where the y coordinate value in the local coordinate system for the fourth columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C43 constituted by a counter electrode formed at a position facing the fourth columnar y-axis positive electrode,
On the upper surface of the support substrate, on the fourth columnar body y-axis negative side electrode formed in a region where the y coordinate value in the local coordinate system of the fourth columnar body is negative, and on the lower surface of the lower end thin portion, A capacitive element C44 configured by a counter electrode formed at a position facing the fourth y-axis negative electrode for the columnar body;
On the upper surface of the support substrate, the fourth columnar body is formed at a predetermined position in the local coordinate system of the fourth columnar body, and the fourth columnar body is formed on the lower surface of the lower end side thin portion. A capacitive element C45 constituted by a counter electrode formed at a position facing the Z-axis displacement detection electrode for use;
5 types of capacitive elements are defined,
For each columnar electrode,
Each of the x-axis positive electrode itself and the x-axis negative electrode itself has a shape that is line symmetric with respect to the x-axis, and the electrode group that includes the x-axis positive electrode and the x-axis negative electrode is the y-axis. Has a line-symmetric shape with respect to
Each of the y-axis positive electrode itself and the y-axis negative electrode itself has a shape that is line-symmetric with respect to the y-axis, and the electrode group that includes the y-axis positive electrode and the y-axis negative electrode is an x-axis. Has a line-symmetric shape with respect to
The Z-axis displacement detection electrode itself has a shape that is line-symmetric with respect to both the x-axis and the y-axis.

(15) According to a fifteenth aspect of the present invention, in the force detection device according to the sixth, twelfth to fourteenth aspects described above,
For a plurality of capacitive elements that are targets for calculating the sum of capacitance values, by performing wiring that is electrically connected to each other, the calculation for calculating the sum in the detection circuit is omitted,
By setting each of the capacitive elements so that the coefficients α, β, αij, and βij are 1, the calculation for calculating the product using the coefficients in the detection circuit is omitted.

(16) According to a sixteenth aspect of the present invention, there is provided a support substrate, a force receiving body arranged above the support substrate, and four columnar bodies for connecting the support substrate and the power receiving body. In a state where the support substrate is fixed, a force detection device that detects the force acting on the force receiving body,
A flexible upper end side thin portion is connected to each upper end of the four columnar bodies, and a flexible lower end side thin portion is connected to each lower end of the four columnar bodies. Is connected,
The upper end side thin part is connected to the power receiving body at the periphery, and the lower surface center part is connected to the upper end of the columnar body,
The lower end side thin portion is connected to the support substrate via a pedestal so that the lower end side thin portion is arranged in parallel to the upper surface of the support substrate at an upper position with a predetermined distance from the upper surface of the support substrate. The part is connected to the lower end of the columnar body,
The XY plane is positioned on or above the upper surface of the support substrate so as to be parallel to the upper surface of the support substrate. Thus, when the XYZ three-dimensional coordinate system is defined,
The four columnar bodies are arranged so that their central axes are parallel to the Z axis, and the first columnar body is arranged at a position where the central axis intersects the positive part of the X axis. The second columnar body is disposed at a position where the central axis intersects the negative portion of the X axis, and the third columnar body is disposed at a position where the central axis intersects the positive portion of the Y axis. The fourth columnar body is disposed at a position where the central axis intersects the negative part of the Y axis,
One electrode is formed on the lower surface of the lower end thin portion, and the other electrode is the upper surface of the support substrate in a space sandwiched between the lower end thin portion of the first columnar body and the upper surface of the support substrate facing the first columnar body. A first sensor composed of a plurality of capacitive elements formed in
One electrode is formed on the lower surface of the lower end thin portion, and the other electrode is the upper surface of the support substrate in a space sandwiched between the lower end thin portion of the second columnar body and the upper surface of the support substrate facing the second columnar body. A second sensor comprising a plurality of capacitive elements formed in
One electrode is formed on the lower surface of the lower end thin portion, and the other electrode is the upper surface of the support substrate in a space sandwiched between the lower end thin portion of the third columnar body and the upper surface of the support substrate facing the third columnar body. A third sensor comprising a plurality of capacitive elements formed in
One electrode is formed on the lower surface of the lower end thin portion and the other electrode is the upper surface of the support substrate in a space sandwiched between the lower end thin portion of the fourth columnar body and the upper surface of the support substrate facing the fourth columnar body. A fourth sensor comprising a plurality of capacitive elements formed in
As a candidate of the capacitive element constituting the first sensor,
When the first columnar body is tilted in the positive direction of the X axis, the capacitance value is increased by narrowing the electrode interval, and when the first columnar body is tilted in the negative direction of the X axis, the electrostatic capacity is increased by increasing the electrode interval. When the capacitance value decreases and the first columnar body inclines in the positive direction of the Y axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the first columnar body is Y A capacitance element C11 formed such that when the electrode is inclined in the negative direction, a part of the electrode interval is narrowed but another part is widened, so that the capacitance value does not change;
When the first columnar body is inclined in the X-axis positive direction, the capacitance value is reduced by increasing the electrode interval, and when the first columnar body is inclined in the X-axis negative direction, the electrode interval is decreased. When the capacitance value increases and the first columnar body inclines in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the first columnar body is Y A capacitive element C12 formed so that a capacitance value does not change by narrowing a part of the electrode interval while expanding another part when tilted in the negative axis direction;
When the first columnar body is tilted in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the first columnar body is tilted in the X-axis negative direction. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value increases by narrowing the electrode spacing when the first columnar body tilts in the positive Y-axis direction. A capacitive element C13 formed such that when the first columnar body is tilted in the negative Y-axis direction, the capacitance value is reduced by increasing the electrode spacing;
When the first columnar body is tilted in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the first columnar body is tilted in the X-axis negative direction. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value decreases by widening the electrode spacing when the first columnar body tilts in the positive Y-axis direction. And a capacitive element C14 formed such that when the first columnar body is inclined in the negative Y-axis direction, the capacitance value increases due to the electrode interval being narrowed;
When the first columnar body is displaced in the Z-axis positive direction, the electrostatic capacity value is reduced by widening the electrode interval, and when the first columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed. When the capacitance value increases and the first columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is narrowed, but another part is widened. A capacitive element C15 formed so that the capacitance value does not change;
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the second sensor,
When the second columnar body is inclined in the positive direction of the X axis, the capacitance value increases due to the electrode interval being narrowed, and when the second columnar body is inclined in the negative direction of the X axis, the electrode interval is increased. When the capacitance value decreases and the second columnar body is inclined in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change, and the second columnar body is Y A capacitive element C21 formed so that a capacitance value does not change by narrowing a part of the electrode spacing while widening another part when tilted in the negative axis direction;
When the second columnar body is inclined in the X-axis positive direction, the capacitance value is reduced by increasing the electrode interval, and when the second columnar body is inclined in the X-axis negative direction, the electrode interval is decreased. When the capacitance value increases and the second columnar body is inclined in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change, and the second columnar body is Y A capacitive element C22 formed so that a capacitance value does not change by narrowing a part of the electrode interval while expanding another part when tilted in the negative axis direction;
When the second columnar body is tilted in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is widened and the capacitance value does not change, and the second columnar body is tilted in the X-axis negative direction. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value increases by narrowing the electrode spacing when the second columnar body tilts in the positive Y-axis direction. A capacitive element C23 formed such that when the second columnar body is inclined in the negative direction of the Y-axis, the capacitance value is reduced by widening the electrode interval;
When the second columnar body is tilted in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is widened and the capacitance value does not change, and the second columnar body is tilted in the X-axis negative direction. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value decreases by widening the electrode spacing when the second columnar body tilts in the positive Y-axis direction. A capacitive element C24 formed such that when the second columnar body inclines in the negative Y-axis direction, the capacitance value increases due to the electrode interval being narrowed;
When the second columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the second columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed to reduce the electrostatic capacity. When the capacitance value increases and the second columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is narrowed, but another part is widened. A capacitive element C25 formed so that the capacitance value does not change;
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the third sensor,
When the third columnar body is inclined in the X-axis positive direction, the capacitance value is increased by narrowing the electrode interval, and when the third columnar body is inclined in the X-axis negative direction, the electrode interval is increased. When the capacitance value decreases and the third columnar body is tilted in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change and the third columnar body is Y A capacitive element C31 formed so that a capacitance value does not change by narrowing a part of the electrode interval but widening another part when tilted in the negative axis direction;
When the third columnar body is inclined in the X-axis positive direction, the capacitance value is reduced by increasing the electrode interval, and when the third columnar body is inclined in the X-axis negative direction, the electrode interval is decreased. When the capacitance value increases and the third columnar body is inclined in the positive direction of the Y axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the third columnar body is Y A capacitive element C32 formed so that a capacitance value does not change by narrowing a part of the electrode interval while expanding another part when tilted in the negative axis direction;
When the third columnar body is inclined in the positive direction of the X axis, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the third columnar body is inclined in the negative direction of the X axis. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value increases by narrowing the electrode spacing when the third columnar body tilts in the positive Y-axis direction. A capacitive element C33 formed such that when the third columnar body is tilted in the negative Y-axis direction, the capacitance value is reduced due to an increase in electrode spacing;
When the third columnar body is inclined in the positive direction of the X axis, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the third columnar body is inclined in the negative direction of the X axis. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value decreases by widening the electrode spacing when the third columnar body tilts in the positive Y-axis direction. A capacitive element C34 formed such that when the third columnar body is inclined in the negative direction of the Y-axis, the capacitance value is increased by reducing the electrode interval;
When the third columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the third columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed to reduce the electrostatic capacity. When the capacitance value increases and the third columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is narrowed, but another part is widened. A capacitive element C35 formed so that the capacitance value does not change;
5 types of capacitive elements are defined,
As a candidate of the capacitive element constituting the fourth sensor,
When the fourth columnar body is inclined in the X-axis positive direction, the capacitance value is increased by narrowing the electrode interval, and when the fourth columnar body is inclined in the X-axis negative direction, the electrode interval is increased. When the capacitance value decreases and the fourth columnar body is inclined in the positive direction of the Y axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change and the fourth columnar body is Y A capacitive element C41 formed so that the capacitance value does not change by narrowing a part of the electrode interval while expanding another part when tilted in the negative axis direction;
When the fourth columnar body is inclined in the X-axis positive direction, the capacitance value is reduced by increasing the electrode interval, and when the fourth columnar body is inclined in the X-axis negative direction, the electrode interval is decreased. When the capacitance value increases and the fourth columnar body tilts in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the fourth columnar body is Y A capacitive element C42 formed so that a capacitance value does not change by narrowing a part of the electrode interval while expanding another part when tilted in the negative axis direction;
When the fourth columnar body is tilted in the positive direction of the X axis, a part of the electrode interval is narrowed, but another part is expanded, so that the capacitance value does not change, and the fourth columnar body is tilted in the negative direction of the X axis. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value increases by narrowing the electrode spacing when the fourth columnar body tilts in the positive Y-axis direction. A capacitive element C43 formed such that when the fourth columnar body is tilted in the negative Y-axis direction, the capacitance value is reduced by increasing the electrode spacing;
When the fourth columnar body is tilted in the positive direction of the X axis, a part of the electrode interval is narrowed, but another part is expanded, so that the capacitance value does not change, and the fourth columnar body is tilted in the negative direction of the X axis. Sometimes, the capacitance value does not change by narrowing part of the electrode spacing but widening another part, and the capacitance value decreases by widening the electrode spacing when the fourth columnar body tilts in the positive Y-axis direction. A capacitive element C44 formed such that when the fourth columnar body is inclined in the negative direction of the Y-axis, the capacitance value is increased by narrowing the electrode interval;
When the fourth columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the fourth columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed to reduce the electrostatic capacity. When the capacitance value increases and the fourth columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is narrowed but another part is widened. A capacitive element C45 formed so that the capacitance value does not change;
5 types of capacitive elements are defined,
The X-axis direction component of the force acting on the force receiving body is Fx, the Y-axis direction component is Fy, the Z-axis direction component is Fz, the moment component around the X-axis is Mx, the moment component around the Y-axis is My, and around the Z-axis the moment component and Mz, Fx, the value of the intermediate stage, respectively used in the process of obtaining the Fy Fx ^*, and Fy ^*, and to exhibit capacitance values of the capacitance elements in each same reference numerals of the capacitive elements ,
As a formula for calculating Fx ^* ,
Fx1 ^* = (C11-C12) + (C21-C22) + (C31-C32) + (C41-C42)
Fx2 ^* = (C11-C12) + (C21-C22)
Fx3 ^* = (C31-C32) + (C41-C42)
Define the following three formulas,
As a formula for obtaining Fy ^* ,
Fy1 ^* = (C13-C14) + (C23-C24) + (C33-C34) + (C43-C44)
Fy2 ^* = (C13-C14) + (C23-C24)
Fy3 ^* = (C33-C34) + (C43-C44)
Define the following three formulas,
As an expression for calculating Fz,
Fz1 = − ((C11 + C12 + C13 + C14 + C15) + (C21 + C22 + C23 + C24 + C25) + (C31 + C32 + C33 + C34 + C35) + (C41 + C42 + C43 + C44 + C45))
Fz2 = − ((C11 + C12 + C13 + C14) + (C21 + C22 + C23 + C24) + (C31 + C32 + C33 + C34) + (C41 + C42 + C43 + C44))
Fz3 = − (C15 + C25 + C35 + C45)
Define the following three formulas,
As an expression for obtaining Mx,
Mx1 = (C41 + C42 + C43 + C44 + C45) − (C31 + C32 + C33 + C34 + C35)
Mx2 = (C41 + C42 + C43 + C44)-(C31 + C32 + C33 + C34)
Mx3 = (C45-C35)
Define the following three formulas,
As an expression for calculating My,
My1 = (C11 + C12 + C13 + C14 + C15) − (C21 + C22 + C23 + C24 + C25)
My2 = (C11 + C12 + C13 + C14) − (C21 + C22 + C23 + C24)
My3 = (C15-C25)
Define the following three formulas,
As an expression for obtaining Mz,
Mz1 = ((C13-C14) + (C41-C42))-((C23-C24) + (C31-C32))
Mz2 = (C13-C14)-(C23-C24)
Mz3 = (C41-C42)-(C31-C32)
When defining the following three formulas,
From the candidate capacitive elements,
Fx = Fxi ^* −Myj (where i = 1 to 3, j = 1 to 3)
Fy = Fyi ^* + Mxj (where i = 1 to 3, j = 1 to 3)
Fz = Fzi (where i = 1 to 3)
Mx = Mxi (where i = 1 to 3)
My = Myi (where i = 1 to 3)
Mz = Mzi (where i = 1 to 3)
Capacitance elements necessary to perform an operation based on an expression selected from the following six expressions (however, selection of the Fx expression and the Fy expression is indispensable) are actually formed. When the capacitance value is used in a plurality of different expressions, a separate capacitor element is physically formed), and a detection circuit for performing the calculation is provided.
Among the capacitive elements that are actually formed, wiring that is electrically connected to each other for a plurality of capacitive elements that are targets of calculating the sum of capacitance values in the calculation based on the selected formula Is given,
For Fxi only moment around the Y axis is obtained in an environment which acts ^* values ^Fxi * (0) and MYJ value ^{Myj (0), Fxi * (} 0) = Myj (0) As is true, Fxi ^* And a capacitive element used for calculating Myj and a capacitive element used for calculating Myj are set.
For the Fyi ^* value Fyi ^* (0) and the Mxj value Mxj (0) obtained in an environment in which only the moment about the X-axis acts, Fyi ^* (0) = Mxj (0) is satisfied. ^The capacitive element used for calculating ^{* and} the capacitive element used for calculating Mxj are set.

(17) According to a seventeenth aspect of the present invention, in the force detection device according to the sixteenth aspect described above, instead of the capacitive element candidate described as the sixteenth aspect,
For each columnar body, an xy two-dimensional local coordinate having an origin at the intersection of the central axis of the columnar body and the upper surface of the support substrate, an x-axis parallel to the X-axis, and a y-axis parallel to the Y-axis When defining a system,
As a candidate of the capacitive element constituting the first sensor,
On the upper surface of the support substrate, on the first columnar body x-axis positive side electrode formed in a region where the x coordinate value in the local coordinate system for the first columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C11 formed by a counter electrode formed at a position facing the first columnar x-axis positive electrode;
On the upper surface of the support substrate, on the first columnar body x-axis negative electrode formed in a region where the x coordinate value in the local coordinate system for the first columnar body is negative, and on the lower surface of the lower end side thin portion, A capacitive element C12 constituted by a counter electrode formed at a position facing the first columnar x-axis negative electrode,
On the upper surface of the support substrate, on the first columnar body y-axis positive side electrode formed in a region where the y coordinate value in the local coordinate system for the first columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C13 configured by a counter electrode formed at a position facing the first y-axis positive electrode for the columnar body;
On the upper surface of the support substrate, on the first columnar body y-axis negative electrode formed in a region where the y coordinate value in the local coordinate system for the first columnar body is negative, and on the lower surface of the lower end thin portion, A capacitive element C14 configured by a counter electrode formed at a position facing the first y-axis negative electrode for the columnar body;
On the upper surface of the support substrate, the first columnar body Z-axis displacement detection electrode formed at a predetermined position in the local coordinate system for the first columnar body, and the first columnar body on the lower surface of the lower end side thin portion A capacitive element C15 constituted by a counter electrode formed at a position facing the Z-axis displacement detection electrode for use;
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the second sensor,
On the upper surface of the support substrate, on the lower surface of the second columnar body x-axis positive side electrode formed in the region where the x coordinate value in the local coordinate system of the second columnar body is positive, and the lower end side thin portion, A capacitance element C21 configured by a counter electrode formed at a position facing the second columnar x-axis positive electrode,
On the upper surface of the support substrate, on the second columnar body x-axis negative electrode formed in a region where the x coordinate value in the local coordinate system for the second columnar body is negative, and on the lower surface of the lower end side thin portion, A capacitive element C22 configured by a counter electrode formed at a position facing the second columnar x-axis negative electrode,
On the upper surface of the support substrate, on the second columnar y-axis positive side electrode formed in the region where the y coordinate value in the local coordinate system is positive, and on the lower surface of the lower end thin portion, A capacitive element C23 configured by a counter electrode formed at a position facing the second columnar y-axis positive side electrode;
On the upper surface of the support substrate, on the second columnar body y-axis negative side electrode formed in a region where the y coordinate value in the local coordinate system for the second columnar body is negative, and on the lower surface of the lower end side thin portion, A capacitive element C24 configured by a counter electrode formed at a position facing the second columnar y-axis negative electrode,
On the upper surface of the support substrate, the second columnar body is formed at a predetermined position in the local coordinate system for the second columnar body, and the second columnar body is formed on the lower surface of the lower end side thin portion. A capacitive element C25 constituted by a counter electrode formed at a position facing the Z-axis displacement detection electrode for use;
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the third sensor,
On the upper surface of the support substrate, on the third columnar body x-axis positive side electrode formed in a region where the x coordinate value in the local coordinate system of the third columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C31 constituted by a counter electrode formed at a position facing the third columnar x-axis positive electrode,
On the upper surface of the support substrate, on the third columnar body x-axis negative electrode formed in a region where the x coordinate value in the local coordinate system is negative, and on the lower surface of the lower end thin portion, A capacitive element C32 configured by a counter electrode formed at a position facing the third columnar x-axis negative electrode,
On the upper surface of the support substrate, on the third columnar body y-axis positive side electrode formed in a region where the y coordinate value in the local coordinate system is positive, and on the lower surface of the lower end side thin portion, A capacitive element C33 constituted by a counter electrode formed at a position facing the third columnar y-axis positive electrode,
On the upper surface of the support substrate, on the third columnar body y-axis negative side electrode formed in the region where the y coordinate value in the local coordinate system is negative, and on the lower surface of the lower end thin portion, A capacitive element C34 constituted by a counter electrode formed at a position facing the third columnar y-axis negative electrode,
A third columnar body Z-axis displacement detection electrode formed at a predetermined position in the local coordinate system of the third columnar body on the upper surface of the support substrate and a third columnar body on the lower surface of the lower end side thin portion. A capacitive element C35 constituted by a counter electrode formed at a position facing the Z-axis displacement detection electrode for use;
5 types of capacitive elements are defined,
As a candidate of the capacitive element constituting the fourth sensor,
On the upper surface of the support substrate, on the fourth columnar x-axis positive electrode formed in the region where the x coordinate value in the local coordinate system is positive, and on the lower surface of the lower end thin portion, A capacitive element C41 constituted by a counter electrode formed at a position facing the fourth columnar x-axis positive side electrode;
On the upper surface of the support substrate, on the fourth columnar x-axis negative electrode formed in the region where the x coordinate value in the local coordinate system is negative, and on the lower surface of the lower end side thin portion, A capacitive element C42 constituted by a counter electrode formed at a position facing the fourth columnar x-axis negative electrode,
On the upper surface of the support substrate, on the fourth y-axis positive side electrode for the columnar body formed in the region where the y coordinate value in the local coordinate system for the fourth columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C43 constituted by a counter electrode formed at a position facing the fourth columnar y-axis positive electrode,
On the upper surface of the support substrate, on the fourth columnar body y-axis negative side electrode formed in a region where the y coordinate value in the local coordinate system of the fourth columnar body is negative, and on the lower surface of the lower end thin portion, A capacitive element C44 configured by a counter electrode formed at a position facing the fourth y-axis negative electrode for the columnar body;
On the upper surface of the support substrate, the fourth columnar body is formed at a predetermined position in the local coordinate system of the fourth columnar body, and the fourth columnar body is formed on the lower surface of the lower end side thin portion. A capacitive element C45 constituted by a counter electrode formed at a position facing the Z-axis displacement detection electrode for use;
5 types of capacitive elements are defined,
For each columnar electrode,
Each of the x-axis positive electrode itself and the x-axis negative electrode itself has a shape that is line symmetric with respect to the x-axis, and the electrode group that includes the x-axis positive electrode and the x-axis negative electrode is the y-axis. Has a line-symmetric shape with respect to
Each of the y-axis positive electrode itself and the y-axis negative electrode itself has a shape that is line-symmetric with respect to the y-axis, and the electrode group that includes the y-axis positive electrode and the y-axis negative electrode is an x-axis. Has a line-symmetric shape with respect to
The Z-axis displacement detection electrode itself has a shape that is line-symmetric with respect to both the x-axis and the y-axis.

(18) According to an eighteenth aspect of the present invention, in the force detection device according to the sixth, twelfth to seventeenth aspects described above,
One electrode constituting a specific one-capacitance element is constituted by an assembly of a plurality of partial electrodes arranged apart from each other.

(19) According to a nineteenth aspect of the present invention, in the force detection device according to the sixth, twelfth to seventeenth aspects described above,
The electrode formed on the upper surface side of the support substrate or the electrode formed on the lower end side thin portion side of the plurality of capacitive elements is physically constituted by a single common electrode.

(20) According to a twentieth aspect of the present invention, in the force detection device according to the nineteenth aspect described above,
Each lower end side thin portion is made of a conductive material, and the lower end side thin portion itself functions as a single common electrode.

(21) According to a twenty-first aspect of the present invention, in the force detection device according to the first to twentieth aspects described above,
The shape and arrangement of each columnar body are symmetrical with respect to both the XZ plane and the YZ plane.

  According to the force detection device of the present invention, the force receiving body and the support substrate are connected by a plurality of columnar bodies, and the pressing force applied from each columnar body to the support substrate and the inclination of each columnar body are individually measured. Since each component of the force applied to the force receiving body can be detected, a detection device having a very simple structure can be realized. In addition, since the other-axis interference due to the moment component detected as the inclination of the columnar body is canceled by the moment component detected as the force applied from the columnar body to the support substrate, the force in the predetermined axial direction acting on the force receiving body Even when the component is detected as the inclination of the columnar body, it is possible to eliminate other-axis interference due to the moment component. Thus, it is possible to realize a force detection device that has a very simple structure, can eliminate interference of other axis components, and can detect force and moment separately.

  Hereinafter, the present invention will be described based on the illustrated embodiments.

<<< §1. Basic structure of equipment >>
First, the basic structure of the force detection device according to the present invention will be described. This basic structure itself has already been disclosed in Patent Documents 1 and 2 described above.

  As shown in FIG. 1, the basic components of the force detection device according to the present invention include a force receiving body 10, a first columnar body 11, a second columnar body 12, a third columnar body 13, and a fourth columnar body. 14, support substrate 20, first sensor 21, second sensor 22, third sensor 23, fourth sensor 24, and detection circuit 30.

  Here, for convenience of explanation, an XYZ three-dimensional coordinate system and an X′Y′Z ′ auxiliary coordinate system obtained by translating the coordinate system upward are defined. In the case of the illustrated example, the origin O of the XYZ three-dimensional coordinate system is defined at the center position of the upper surface of the support substrate 20, and the upper surface of the support substrate 20 is included in the XY plane. The right side of the figure is the X-axis positive direction, the diagonally back side of the figure is the Y-axis positive direction, and the upper side of the figure is the Z-axis positive direction. On the other hand, the origin O ′ of the X′Y′Z ′ auxiliary coordinate system is at a position obtained by moving the origin O by a predetermined distance in the positive direction of the Z axis. Specifically, the origin O ′ is located at the center of the force receiving body 10. Therefore, the X axis and the X ′ axis are parallel, the Y axis and the Y ′ axis are parallel, and the Z axis and the Z ′ axis overlap each other.

  The force receiving body 10 is a component that receives a force to be detected, and the force receiving body 10 has the origin O ′ of the X′Y′Z ′ auxiliary coordinate system at the center of the force receiving body 10. This is a convenience for explaining the force acting on the. In the figure, the force Fx in the X-axis direction, the force Fy in the Y-axis direction, and the force Fz in the Z-axis direction acting on the force receiving body 10 are respectively shown along the X ′ axis, the Y ′ axis, and the Z ′ axis. Of course, these forces are forces parallel to the X-axis, Y-axis, and Z-axis, respectively, and the X-axis direction component of the force applied to the force receiving member 10 is represented by the Y-axis. This indicates the direction component and the Z-axis direction component.

  As described above, the forces Fx, Fy, and Fz may be considered as forces along the coordinate axes of the X′Y′Z ′ auxiliary coordinate system or forces along the coordinate axes of the XYZ three-dimensional coordinate system. Although there is no difference in the essence as a physical quantity, the essence as a physical quantity varies depending on where the origin position of the coordinate system is taken for the moments Mx, My, and Mz. In particular, since the present invention relates to a force detection device having high measurement accuracy that eliminates interference of other axis components, here, an XYZ three-dimensional coordinate system and an X′Y′Z ′ auxiliary coordinate system are clearly defined. We will treat them separately.

  That is, the forces Fx, Fy, Fz and moments Mx, My, Mz to be detected by the force detection device according to the present invention are applied to the forces acting around the coordinate axes in the XYZ three-dimensional coordinate system and around the coordinate axes. This is why the arrows indicating the moments Mx and My are drawn around the X axis and the Y axis in FIG. 1 (the Z axis and the Z ′ axis overlap each other, so the moment Mz is Z It can be considered as a moment around the 'axis). In other words, the object to which the moments Mx and My directly act is the force receiving body 10, but these moments act to rotate the force receiving body 10 about the origin O 'at the center position. Rather than fulfilling the above, the force receiving body 10 is rotated around the origin O of the XYZ three-dimensional coordinate system.

  Eventually, this force detection device has an X-axis direction component Fx, a Y-axis direction component Fy, a Z-axis direction component Fz, and a moment component Mx around the X-axis in the XYZ three-dimensional coordinate system. , The moment component My around the Y axis and the moment component Mz around the Z axis are independently detected.

  In the present application, the term “force” is appropriately used when it means a force component in a specific coordinate axis direction and when it means a collective force including a moment component. For example, in FIG. 1, the forces Fx, Fy, and Fz mean force components in the coordinate axis directions that are not moments, but six forces Fx, Fy, Fz, Mx, My, and Mz. In this case, it means a collective force including a force component in each coordinate axis direction and a moment component around each coordinate axis.

  The support substrate 20 is a component that is disposed below the force receiving body 10 and fulfills the function of supporting the force receiving body 10. As described above, in the example shown here, the upper surface of the support substrate 20 is included in the XY plane. This force detection device detects a force acting on the force receiving body 10 in a state where the support substrate 20 is fixed.

  The first columnar body 11 to the fourth columnar body 14 are members that connect the force receiving body 10 and the support substrate 20, and are all disposed so that the central axis thereof is parallel to the Z axis. Moreover, the first columnar body 11 is arranged at a position where the central axis intersects the positive part of the X axis, and the second columnar body 12 is a position where the central axis intersects the negative part of the X axis. The third columnar body 13 is disposed at a position where its central axis intersects the positive part of the Y axis, and the fourth columnar body 14 is disposed at a position where the central axis intersects the negative part of the Y axis. It is arranged at the position to do.

  In practice, it is preferable that the first columnar body 11 to the fourth columnar body 14 have the same material and the same size. This is because the detection sensitivity of the first sensor 21 to the fourth sensor 24 can be made the same if these materials and sizes are made the same. If the materials and sizes are different from each other, it is difficult to make the sensitivity of each sensor the same, and a device for correcting the sensitivity is required. For the same reason, the shape and arrangement of each columnar body are preferably plane-symmetric with respect to both the XZ plane and the YZ plane.

  Although not shown in FIG. 1, the upper ends of the respective columnar bodies 11 to 14 are connected to the force receiving body 10 through flexible members, and the respective columnar bodies 11 to 11 are connected. The lower end of 14 is connected to the support substrate 20 via a flexible connection member. In short, the first columnar body 11 to the fourth columnar body 14 are connected to the force receiving body 10 and the support substrate 20 with flexibility. Here, flexibility is synonymous with elasticity, and in a state where no force is applied to the force receiving body 10, the force receiving body 10 takes a fixed position with respect to the support substrate 20. When some force is applied to the force body 10, the flexible connecting member is elastically deformed, and the relative position between the force receiving body 10 and the support substrate 20 is changed. Of course, when the force acting on the force receiving body 10 disappears, the force receiving body 10 returns to the original fixed position.

  After all, in the case of the example shown in FIG. 1, the upper end portion and the lower end portion of the first columnar body 11 to the fourth columnar body 14 are each constituted by a flexible connecting member (of course. The whole of the first columnar body 11 to the fourth columnar body 14 may be made of a flexible material). And since this connection member produces a certain amount of elastic deformation, the 1st columnar body 11-the 4th columnar body 14 can incline with respect to the force receiving body 10 and the support substrate 20. FIG. Further, this connecting member can be expanded and contracted in the vertical direction (Z-axis direction) in the figure, and when the force receiving body 10 is moved in the upward direction (+ Z-axis direction) in the figure, the connecting member expands and contracts, The distance between the force receiving body 10 and the support substrate 20 increases. Conversely, when the force receiving body 10 is moved in the downward direction (−Z-axis direction) in the figure, the connecting member expands and contracts, and the force receiving body 10 and the support substrate 20 are expanded. The distance to will be narrowed. Of course, the degree of such displacement and inclination increases according to the magnitude of the force acting on the force receiving body 10.

  The first sensor 21 to the fourth sensor 24 detect the inclination of the first columnar body 11 to the fourth columnar body 14, respectively, and support substrates from the first columnar body 11 to the fourth columnar body 14. 20 is a force sensor that detects a force in the Z-axis direction that is applied toward 20. Specifically, as will be described later, each capacitor is composed of a plurality of capacitive elements. When a force is applied to the force receiving body 10, the force is transmitted to the support substrate 20 through the columnar bodies 11 to 14. Each of the sensors 21 to 24 has a function of detecting a dynamic phenomenon generated in the vicinity of the lower end portion of each of the columnar bodies 11 to 14 by the force transmitted in this way. More specifically, as described in detail later, the function of detecting the inclination of the columnar body by detecting the force generated by the tilting of the columnar body and the entire columnar body are applied to the support substrate. And a function of detecting a pressing force (downward in the figure-force in the Z-axis direction) or a pulling force (upward in the figure + force in the Z-axis direction).

  The detection circuit 30 is a component that performs processing for detecting a force or moment applied to the force receiving body 10 based on capacitance values of a plurality of capacitive elements constituting the sensors 21 to 24, and is an XYZ three-dimensional. A signal indicating force components Fx, Fy, Fz in each coordinate axis direction in the coordinate system and a signal indicating moment components Mx, My, Mz around each coordinate axis are output. Actually, detection of force or moment is performed based on the inclination of the columnar body and the pressing force / tensile force applied to the support substrate.

<<< §2. Operating principle of the device >>>
Next, the basic operation principle of the force detection device shown in FIG. 1 will be described with reference to the front view of FIG. Here, for convenience of explanation, only the operations related to the first columnar body 11 and the second columnar body 12 are shown, but the operations related to the third columnar body 13 and the fourth columnar body 14 are also the same. It is.

  FIG. 2A shows a state in which no force is applied to the force detection device, and the force receiving body 10 maintains a fixed position with respect to the support substrate 20. Of course, even in this state, since the weight of the force receiving member 10 and the like is applied on the support substrate 20, the support substrate 20 receives some force from the first columnar body 11 and the second columnar body 12. However, the force received in this state is a force in a steady state, and even if such a force is detected by the first sensor 21 or the second sensor 22, the force output from the detection circuit 30. And the detected value of moment is adjusted to be zero. In other words, the detection circuit 30 is based on the detection results of the sensors 21 to 24 in such a steady state as a reference, and when any change occurs, the change is expressed as a force or moment acting on the force receiving body 10. It has a function to detect.

  Now, let us consider a case where a force + Fx in the positive direction of the X axis is applied to the force receiving member 10 as shown in FIG. 2 (b). This corresponds to the case where a force that pushes the position of the origin O ′ in the right direction in the figure is applied. In this case, as shown in the figure, the force receiving body 10 slides in the right direction in the figure, and the first columnar body 11 and the second columnar body 12 are inclined in the right direction in the figure. Become. Here, the inclination of the first columnar body 11 at this time is referred to as θ1, and the inclination of the second columnar body 12 is referred to as θ2. Also, the angles θ1 and θ2 indicating the degree of inclination in the direction toward the X axis in the XZ plane are referred to as “degree of inclination in the X axis direction”. Similarly, an angle indicating the degree of inclination in the direction toward the Y axis in the YZ plane is referred to as “degree of inclination in the Y axis direction”. In the case of the illustrated example, since the two columnar bodies 11 and 12 are arranged on the X axis, the inclination in the Y axis direction is zero.

  Note that when the columnar bodies 11 and 12 are inclined, the distance between the force receiving body 10 and the support substrate 20 is slightly reduced. Strictly speaking, the force receiving body 10 performs a complete parallel movement in the X-axis direction. However, if the inclination is relatively small, the amount of movement in the −Z-axis direction can be ignored, so here, for convenience of explanation. Suppose that the force receiving body 10 has moved only in the X-axis direction.

  On the other hand, let us consider a case where a moment + My around the Y-axis acts on the force receiving member 10 as shown in FIG. In FIG. 2 (c), since the Y axis is a vertical axis toward the back side of the paper surface at the position of the origin O, in the figure, the moment + My is the clockwise rotation of the force receiving member 10 around the origin O. It corresponds to a force that rotates in the direction. In the present application, the rotation direction of the right screw when the right screw is advanced in the positive direction of a predetermined coordinate axis is defined as a positive moment around the coordinate axis. As described above, the moment + My is not a force that rotates the force receiving member 10 about the origin O ′ but a force that rotates the origin 10 about the origin O (if the error between the two is within an allowable range, the moment is converted to the origin O It can be handled as a rotational force centered on ′.)

  In this case, as shown in the figure, a reduction force acts on the first columnar body 11 and an extension force acts on the second columnar body 12. As a result, a pressing force (force in the −Z axis direction: here, referred to as force −fz) acts on the support substrate 20 from the first columnar body 11, and the second columnar body 12. Therefore, a pulling force (+ Z-axis direction force: here, referred to as force + fz) is applied to the support substrate 20.

  As described above, in the force detection device having the structure that takes a dynamic behavior as shown in FIG. 2, the force Fx in the X-axis direction acts on the force receiving member 10 and the moment My around the Y-axis acts. In some cases, the mode of the force transmitted to the support substrate 20 via the two columnar bodies 11 and 12 is different. Therefore, both can be distinguished and detected separately.

  That is, when the force Fx in the X-axis direction is applied, as shown in FIG. 2 (b), the two columnar bodies 11 and 12 are inclined in the X-axis direction to generate the inclinations θ1 and θ2. Thus, a force according to such an inclination is transmitted to the support substrate 20. Here, the first columnar body 11 and the second columnar body 12 and the flexible connecting members for connecting them to the support substrate 20 are made of the same material and the same size. If the force detection device is configured to be bilaterally symmetric with respect to the YZ plane in the figure, the inclination θ1 = θ2. Therefore, the sum (θ1 + θ2) of both is a value indicating the force Fx in the X-axis direction. If the inclination θ is handled with a sign (for example, if the inclination in the X-axis positive direction is treated as positive, and the inclination in the X-axis negative direction is treated as negative), the applied force X in the X-axis direction Fx Can be detected including the sign.

  However, in the present invention, as will be described later, the inclination of the first columnar body 11 and the second columnar body 12 is the force applied to the support substrate 20 by the first sensor 21 and the second sensor 22. Will be detected. In order to perform such detection, the force applied from each columnar body to the support substrate 20 may be detected for each individual portion. For example, in FIG. 2B, when the stress generated in the connection portion between the first columnar body 11 and the support substrate 20 is considered, the stress is generated in the right side portion and the left side portion of the bottom portion of the first columnar body 11. It can be seen that the direction of the stress is different. That is, in the illustrated example, since the first columnar body 11 is inclined to the right side, a pressing force is generated on the right side portion of the bottom of the first columnar body 11 and presses the upper surface of the support substrate 20 downward. While a force is generated, a pulling force is generated in the left portion, and a force is generated that pulls the upper surface of the support substrate 20 upward. Thus, by detecting the difference in stress between the left and right portions of the bottom of the first columnar body 11, the inclination of the first columnar body 11 can be obtained. The specific method will be described in detail in §3.

  After all, in order to detect the force Fx in the X-axis direction by this force detection device, the first sensor 21 has a function of detecting the tilt state of the first columnar body 11 in the X-axis direction with respect to the support substrate 20. The second sensor 22 may be provided with a function of detecting the inclined state of the second columnar body 12 in the X-axis direction with respect to the support substrate 20. The first sensor 21 has a function of detecting the inclination θ1 of the first columnar body 11 in the X-axis direction, and the second sensor 22 determines the inclination of the second columnar body 12 in the X-axis direction. If the detection circuit 30 has a function of detecting, the detection circuit 30 has an inclination θ1 in the X-axis direction detected by the first sensor 21 and an inclination θ2 in the X-axis direction detected by the second sensor 22. Based on the sum of, a process of detecting the X-axis direction component Fx of the force acting on the force receiving body 10 can be performed.

  On the other hand, when the moment My around the Y-axis acts, as shown in FIG. 2C, the pressing force −fz and the pulling force + fz are applied to the support substrate 20 from the two columnar bodies 11 and 12. Communicated. The force transmitted in this way is different from the force when the columnar body is inclined. That is, when the columnar body is inclined as shown in FIG. 2 (b), the stress generated at the bottom of the columnar body is different between the right side portion and the left side portion. However, when the moment My is applied as shown in FIG. 2 (c), the pressing force -fz is applied by the entire first columnar body 11, and the tensile force + fz is applied by the entire second columnar body 12. become.

  As described above, with respect to the action of the force Fx in the X-axis direction, as shown in FIG. 2B, the first columnar body 11 and the second columnar body 12 are equivalently inclined in the same direction. Whereas an event occurs, with respect to the action of the moment My around the Y-axis, as shown in FIG. 2 (c), one of the first columnar body 11 and the second columnar body 12 is pressed. There will be a conflicting event of giving -fz and the other giving a pulling force + fz. Therefore, the applied moment My can be obtained as a difference between the pulling force + fz and the pressing force −fz, that is, (+ fz) − (− fz) = 2fz.

  In short, in order to detect the moment My around the Y-axis by this force detection device, the first sensor 21 has a function of detecting the force applied to the support substrate 20 from the entire first columnar body 11. Therefore, the second sensor 22 may have a function of detecting a force applied to the support substrate 20 from the entire second columnar body 12. The first sensor 21 has a function of detecting a force in the Z-axis direction applied to the support substrate 20 from the entire first columnar body 11, and the second sensor 22 is the entire second columnar body 12. If the detection circuit 30 has a function of detecting a force applied to the support substrate 20 from the Z-axis direction, the detection circuit 30 can detect the force detected by the first sensor 21 and the second sensor. Based on the difference between the force in the Z-axis direction detected by 22 and the moment My around the Y-axis of the force acting on the force receiving body 10 can be detected.

  As described above, only the operation related to the first columnar body 11 and the second columnar body 12 has been described with reference to FIG. 2, but the operation related to the third columnar body 13 and the fourth columnar body 14 is also performed. It is the same. That is, if the X axis in the explanation of the operation in FIG. 2 is replaced with the Y axis, the force Fy in the Y axis direction applied to the force receiving body 10 using the detection function of the third sensor 23 and the fourth sensor 24. It is possible to detect the moment Mx around the X axis.

  Further, when a force −Fz in the negative Z-axis direction is applied to the force receiving body 10, a pressing force −fz is applied to the support substrate 20 from all of the four columnar bodies 11 to 14. When the force + Fz in the positive axial direction is applied, the tensile force + fz is applied to the support substrate 20 from all of the four columnar bodies 11 to 14. Therefore, the applied force Fz in the Z-axis direction can be obtained as the sum of the pressing forces −fz applied from the four columnar bodies 11 to 14 or the sum of the pulling forces + fz.

  Furthermore, when the moment Mz around the Z-axis is applied to the force receiving body 10, the four columnar bodies 11 to 14 are inclined clockwise or counterclockwise when observed from above. The moment Mz can also be detected by detecting the inclination directions of the four columnar bodies 11 to 14.

<<< §3. Force sensor used in the present invention >>>
The force detection device shown in FIG. 1 is provided with a first sensor 21 to a fourth sensor 24. These sensors are force sensors that detect the force applied to the support substrate 20 from the first columnar body 11 to the fourth columnar body 14, respectively, but based on the principle described in §2, In order to detect Fx, Fy, Fz, moments Mx, My, and Mz, the force generated at the lower end of each columnar body 11-14 due to the inclination of each columnar body 11-14 and the tensile force / push applied by the entire columnar body 11-14. A function for detecting the pressure independently is required.

  Therefore, in the present invention, as each of the sensors 21 to 24, a capacitive force sensor having a plurality of capacitive elements is used. FIG. 3 is a side sectional view showing an example of such a capacitive element type multi-axis force sensor. As shown in the figure, this multi-axis force sensor includes a plate-like support substrate 40, a bowl-shaped connection member 50 disposed thereon, a columnar body 60, and fixed electrodes E <b> 1 to E1 disposed on the upper surface of the support substrate 40. E5. As shown in the top view of FIG. 4, the hook-shaped connection member 50 has a shape in which a circular flat-bottomed hook is turned down.

  Here, for convenience of explanation, an xyz three-dimensional coordinate system is defined in which the local origin is set at the center of the upper surface of the support substrate 40 and the x, y, and z axes are respectively defined in the illustrated direction. The xyz three-dimensional coordinate system indicated by lowercase letters is a local coordinate system defined at the lower ends of the individual columnar bodies 11 to 14, and is regular with respect to the XYZ three-dimensional coordinate system indicated by uppercase letters. That is, the x axis and the X axis are parallel, the y axis and the Y axis are parallel, and the z axis and Z are parallel.

  As shown in the side sectional view of FIG. 3, the bowl-shaped connecting member 50 includes a disk-shaped thin part 51 corresponding to the flat bottom part of the bowl, a cylindrical side wall part 52 that supports the periphery thereof, The side wall portion 52 includes a fixing portion 53 for fixing the side wall portion 52 to the upper surface of the support substrate 40, and a cylindrical columnar body 60 is connected to the central portion of the upper surface of the thin portion 51. The local origin is defined at the intersection point between the extension line of the central axis of the cylindrical columnar body 60 and the upper surface of the support substrate 40.

  Here, in this example, the support substrate 40 and the columnar body 60 have sufficient rigidity, but the hook-shaped connection member 50 has flexibility (in other words, a property that causes elastic deformation). Yes. In this example, the hook-shaped connection member 50 is configured by a thin metal plate, and the support substrate 40 and the columnar body 60 are configured by an insulating material.

  As shown in the top view of FIG. 5, five fixed electrodes E <b> 1 to E <b> 5 are formed on the top surface of the plate-like support substrate 40. Here, the fixed electrode E1 is arranged in the positive part of the x axis, the fixed electrode E2 is arranged in the negative part of the x axis, the fixed electrode E3 is arranged in the positive part of the y axis, and the fixed electrode E4 is y They are arranged in the negative part of the axis, and all are electrodes having the same shape and the same size in the shape of a fan that is line-symmetric with respect to each coordinate axis. On the other hand, the fixed electrode E5 is a circular electrode arranged at the position of the local origin.

  The broken lines in FIG. 5 indicate the position of each part of the hook-shaped connection member 50 fixed on the support substrate 40. As illustrated, the thin portion 51 is disposed above the support substrate 40 so as to face all of the fixed electrodes E1 to E5. If the thin portion 51 is made of a conductive material such as a metal plate, the thin portion 51 has flexibility and conductivity, and the thin portion 51 itself functions as one common displacement electrode and faces it. A capacitive element is formed between each of the fixed electrodes E1 to E5. Here, the five sets of capacitive elements configured by the fixed electrodes E1 to E5 and the thin portion 51 functioning as a common displacement electrode are referred to as capacitive elements C1 to C5, respectively.

  Subsequently, when forces having various directional components are applied to the columnar body 60, how the hook-like connecting member 50 is deformed and what changes are made in the capacitance values of the capacitive elements C1 to C5. Think about what happens.

  First, as shown in FIG. 6, consider a case where a force + fx in the positive x-axis direction is applied to the upper portion of the columnar body 60. This means that a force that tilts the columnar body 60 to the right side (the positive direction of the x-axis) is applied. In this case, the flexible hook-shaped connecting member 50 is deformed as shown in the figure, and the thin portion 51 is inclined so that the right portion moves downward and the left portion moves upward. As a result, the distance between both electrodes (the fixed electrode E1 and the thin portion 51) of the capacitive element C1 is reduced and the capacitance value increases, but the distance between both electrodes (the fixed electrode E2 and the thin portion 51) of the capacitive element C2 is As it spreads, the capacitance value decreases. At this time, for the other three sets of capacitive elements C3 to C5, the distance between the electrodes is reduced in the right half, but the distance between the electrodes is increased in the left half, so that the total capacitance value does not change.

  On the other hand, as shown in FIG. 7, consider a case where a force −fx in the negative x-axis direction is applied to the upper portion of the columnar body 60. This means that a force that tilts the columnar body 60 to the left (in the negative x-axis direction) is applied. In this case, the flexible hook-shaped connection member 50 is deformed as shown in the figure, and the thin portion 51 is inclined so that the left portion moves downward and the right portion moves upward. As a result, the capacitance value of the capacitive element C1 decreases and the capacitance value of the capacitive element C2 increases.

  Eventually, the force fx in the x-axis direction applied to the columnar body 60 can be obtained as a difference between the capacitance value of the first capacitance element C1 and the capacitance value of the second capacitance element C2. The magnitude of the obtained difference indicates the magnitude of the applied force, and the sign of the obtained difference indicates the direction of the applied force. Based on the same principle, the force fy in the y-axis direction applied to the columnar body 60 is obtained as a difference between the capacitance value of the third capacitance element C3 and the capacitance value of the fourth capacitance element C4. be able to.

  The force fx thus obtained indicates the degree of inclination of the columnar body 60 in the x-axis direction, and the force fy indicates the degree of inclination of the columnar body 60 in the y-axis direction. Eventually, the inclination of the columnar body 60 in the x-axis direction can be obtained as a difference between the capacitance value of the first capacitive element C1 and the capacitance value of the second capacitive element C2, and The inclination with respect to the y-axis direction can be obtained as a difference between the capacitance value of the third capacitance element C3 and the capacitance value of the fourth capacitance element C4. In other words, the support substrate 40 of the columnar body 60 is based on the difference between the force applied from the first portion at the lower end of the columnar body 60 and the force applied from the second portion at the lower end of the columnar body 60. Can be detected.

  Next, as shown in FIG. 8, consider a case where a force −fz in the negative z-axis direction is applied to the columnar body 60. In this case, since a downward force in the figure is applied to the entire columnar body 60, the columnar body 60 is not inclined and is moved downward with respect to the bowl-shaped connecting member 50 by the entire columnar body 60. The flexible hook-shaped connecting member 50 is deformed as shown in the figure, and the gap between all the electrodes of the five capacitive elements C1 to C5 is narrowed. Will increase. Conversely, when a force + fz for pulling up the columnar body 60 is applied, the columnar body 60 as a whole exerts an upward pulling force on the bowl-shaped connection member 50, and five sets of capacitive elements All the electrode intervals of C1 to C5 are widened, and the capacitance value is reduced.

  After all, in an environment where only the force fz in the z-axis direction is acting on the columnar body 60, if any one of the capacitance values of the first to fifth capacitive elements C1 to C5 is detected, it acts. The force fz can be determined. However, in an environment where forces fx and fy of other axial components are mixed, for example, the capacitance value of the capacitive element C1 is obtained alone, or the capacitance value of the capacitive element C3 is obtained alone. However, these are not necessarily values indicating the force fz in the z-axis direction. In any environment, in order to detect the force fz in the z-axis direction, the capacitance value of the capacitive element C5 may be used. As described above, when the force fx in the x-axis direction or the force fy in the y-axis direction is applied, the capacitance value of the capacitive element C5 does not change, so the capacitance value of the capacitive element C5 is used. Then, only the force fz in the z-axis direction can be detected independently.

  However, another method may be used to independently detect only the force fz in the z-axis direction. For example, the sum of the capacitance value of the capacitive element C1 and the capacitance value of the capacitive element C2 can be obtained and used as a detected value of the force fz in the z-axis direction. For the action of the force fx in the x-axis direction, the increase / decrease in the capacitance value of the capacitive element C1 and the increase / decrease in the capacitance value of the capacitive element C2 have a complementary relationship. The component of the force fx in the x-axis direction can be canceled, and only the detected value of the force fz in the z-axis direction can be taken out. Similarly, the sum of the capacitance value of the capacitive element C3 and the capacitance value of the capacitive element C4 can be obtained and used as a detected value of the force fz in the z-axis direction. Further, the sum of the capacitance values of the four sets of capacitance elements C1 to C4 and the sum of the capacitance values of the five sets of capacitance elements C1 to C5 are obtained and used as the detection value of the force fz in the z-axis direction. It is also possible to do.

  As described above, when the multi-axis force sensor shown in FIG. 3 is used, the inclination degree (force fx) of the columnar body 60 in the x-axis direction, the inclination degree (force fy) of the columnar body 60 in the y-axis direction, and the columnar shape The force (force fz) applied to the support substrate 40 from the entire body 60 can be detected. This means that the multi-axis force sensor shown in FIG. 3 can be used as each of the sensors 21 to 24 in the force detection device shown in FIG.

  After all, as a general theory, as a detector for detecting the inclination of the columnar body in the X-axis direction, the first electrode E1 formed in the region where the x coordinate value is positive on the upper surface of the support substrate 40. (Supporting substrate 40), a first capacitive element C1 composed of the (x-axis positive side electrode), a first counter electrode formed at a position facing the first electrode E1 on the lower surface of the thin portion. The second electrode E2 (x-axis negative side electrode) formed in a region where the x-coordinate value is negative on the upper surface of the first electrode and the second electrode E2 formed on the lower surface of the thin portion at a position facing the second electrode E2. A second capacitance element C2 constituted by two counter electrodes, and the difference between the capacitance value C1 of the first capacitance element and the capacitance value C2 of the second capacitance element is columnar What is necessary is just to prepare the detector calculated | required as the inclination degree regarding the X-axis direction of a body.

  Further, as a detector for detecting the inclination of the columnar body in the Y-axis direction, a third electrode E3 (y-axis positive electrode) formed in a region where the y coordinate value is positive on the upper surface of the support substrate 40. And a third capacitive element C3 formed on the lower surface of the thin portion at a position facing the third electrode E3, and a y-coordinate value on the upper surface of the support substrate 40. A fourth electrode E4 (y-axis negative side electrode) formed in a negative region, and a fourth counter electrode formed at a position facing the fourth electrode E4 on the lower surface of the thin portion, And a difference between the capacitance value C3 of the third capacitance element and the capacitance value C4 of the fourth capacitance element is inclined with respect to the Y-axis direction of the columnar body. What is necessary is just to prepare the detector calculated | required as a degree.

  Furthermore, as a detector for detecting the force in the Z-axis direction applied to the support substrate from the entire columnar body, a fifth electrode E5 (Z-axis displacement detection electrode) formed on the upper surface of the support substrate 40, and On the lower surface of the thin portion, there is a fifth capacitive element C5 composed of a fifth counter electrode formed at a position facing the fifth electrode E5, and the capacitance of the fifth capacitive element What is necessary is just to prepare the detector which calculates | requires value C5 as the force regarding the Z-axis direction applied with respect to a support substrate from the whole columnar body.

  In order to allow each detector to independently detect only the detection object that it takes charge of, the following symmetry is practically maintained in the shape and arrangement of each electrode. It is preferable to do this. First, each of the first electrode E1 itself and the second electrode E2 itself has a shape that is line-symmetric with respect to the x-axis, and the electrode group composed of the first electrode E1 and the second electrode E2 is: The shape is symmetrical with respect to the y-axis. In addition, the third electrode E3 itself and the fourth electrode itself E4 have a shape that is line-symmetric with respect to the y-axis, and the electrode group composed of the third electrode E3 and the fourth electrode E4 is: The shape is symmetrical with respect to the x axis. On the other hand, the fifth electrode E5 itself has a shape that is line-symmetric with respect to both the x-axis and the y-axis.

  Even if such symmetry is not maintained in the arrangement and shape of each electrode, it is possible to cause each detector to detect only the detection target, but various correction terms are used. This is not preferable in practice because it requires operations and the like. Therefore, in practice, it is preferable to perform an electrode configuration that satisfies the above symmetry.

<<< §4. Structure of specific embodiment >>
Subsequently, main structural portions of the force detection device according to the specific embodiment of the present invention will be described with reference to FIGS. The specific embodiments described here are also already disclosed in Patent Documents 1 and 2 described above.

  FIG. 9 is a top view of the force detection device according to the basic embodiment of the present invention. FIG. 10 shows a side sectional view of the device taken along the XZ plane, and FIG. 11 shows a side sectional view taken along the YZ plane. As shown in FIG. 10 or FIG. 11, basic components of the force detection device are a force receiving body 100, an intermediate body 200, and a support substrate 300, all of which have a square shape whose upper surface is parallel to the XY plane. The plate-shaped member which did is made into the basic form. 10 and 11 are side cross-sectional views at different cutting positions, but the geometric structures appearing in the drawings are exactly the same. The difference between them is only the sign of each part. This is because the basic structure of this device is plane symmetric with respect to the XZ plane and also plane symmetric with respect to the YZ plane.

  Similar to the example described in §1, in this example, an XYZ three-dimensional coordinate system and an X′Y′Z ′ auxiliary coordinate system obtained by translating the coordinate system in the Z-axis direction are defined. The X′Y′Z ′ auxiliary coordinate system is a coordinate system having the origin O ′ at the center position of the force receiving body 100. On the other hand, the origin O of the XYZ three-dimensional coordinate system is defined at a position where the upper surface center point of the support substrate 300 is slightly shifted in the positive direction of the Z axis. 10 and 11, the origin O is slightly shifted from the upper surface of the support substrate 300, and the X axis and the Y axis are slightly shifted from the upper surface position of the support substrate 300 for this reason.

  In the first place, the XYZ three-dimensional coordinate system is a conceptually defined coordinate system, and no matter where the origin O is defined, the physical structure of the force detection device is not affected. However, for a user who intends to perform highly accurate measurement using this force detection device, the moment accurately detected by this detection device is about a coordinate axis having a specific origin O. It is necessary to clarify that it is a moment. As will be described later, the correction for eliminating the other-axis interference that is the point of the present invention is a correction that cancels out the interference with respect to the moment around the coordinate axis having the specific origin O. Therefore, in carrying out the present invention, it is necessary to set a specific origin O so that such correction has an accurate meaning.

This specific origin O may be defined at the position of the upper surface center point of the support substrate 300 as in the example described in §1. However, in the case of the embodiment shown here, the present inventor believes that a more preferable result can be obtained if the position of the origin O is defined slightly upward. This is because, as described in §3, in the present invention, the force (inclination) acting on the lower end of each columnar body is detected using a capacitive sensor as shown in FIG. This is because it is considered most preferable to define a coordinate system in which the XY plane is located at the center position of the capacitive sensor, that is, at an intermediate position between a pair of electrodes constituting the capacitive element. Therefore, in the case of the embodiment shown here, the position of the origin O is above the center point of the upper surface of the support substrate 300 by ½ of the distance between the pair of electrodes constituting the capacitive element, when the thickness of the electrode is ignored. It will be the position moved to.

  However, since it is not easy to theoretically analyze the ideal position of the origin O, it is not always optimal to define the origin O at the above-mentioned position depending on the structure of the actual force detection device. Absent. The position of the origin O does not need to be defined so strictly. If it is defined at the upper surface near the center of the support substrate or a predetermined point above it, the effect of the present invention can be obtained sufficiently in practice.

  Now, the force receiving body 100, the intermediate body 200, and the support substrate 300 made of a plate-like member having a square top surface are all parallel to the XY plane, and each side has an X axis or They are arranged so as to be parallel to the Y axis.

  As shown in FIG. 9, the force receiving body 100 is basically a plate-like member having a square upper surface, but the four cylindrical protrusions 110, 120, 130, and 140 are directed downward from the lower surface. It is growing. FIG. 12 is a cross-sectional view showing a state where the force receiving body 100 is cut along the X′Y ′ plane.

  As shown in FIG. 12, annular grooves G11, G12, G13, and G14 are formed around the base portions of the four cylindrical protrusions 110, 120, 130, and 140, and the groove G11. , G12, G13, and G14, the plate-shaped force receiving member 100 has a flexible upper end side thin portion 115, 125, 135, 145 as shown in FIGS. Is formed. Eventually, the four cylindrical protrusions 110, 120, 130, and 140 are connected to the plate-shaped force receiving body 100 through the upper-end-side thin portions 115, 125, 135, and 145.

  On the other hand, the intermediate body 200 is a member bonded to the upper surface of the support substrate 300, and is basically a plate-shaped member having a square upper surface. As shown in FIGS. 10 and 11, four cylindrical protrusions 210, 220, 230, and 240 extend upward from the upper surface of the intermediate body 200. Annular grooves G21, G22, G23, and G24 are formed around the base portions of the four cylindrical protrusions 210, 220, 230, and 240. Further, on the lower surface of the intermediate body 200, Cylindrical grooves G31, G32, G33, and G34 are formed. The groove portions G21, G22, G23, G24 provided on the upper surface of the intermediate body 200 and the groove portions G31, G32, G33, G34 provided on the lower surface are all center axes of the cylindrical protrusion portions 210, 220, 230, 240. It has a circular outline of the same size around the position of.

  As shown in FIG. 10, the lower end side thin portion 215 exists as a boundary wall between the groove portions G21 and G31, and the lower end side thin portion 225 exists as a boundary wall between the groove portions G22 and G32. Further, as shown in FIG. 11, the lower end side thin portion 235 exists as a boundary wall between the groove portions G23 and G33, and the lower end side thin portion 245 exists as a boundary wall between the groove portions G24 and G34. To do.

  FIG. 13 is a cross-sectional view showing a state in which the intermediate body 200 shown in FIGS. 10 and 11 is cut along a cutting line 13-13. The state in which the groove portions G21, G22, G23, and G24 are formed around the four cylindrical protrusion portions 210, 220, 230, and 240 is clearly shown. FIG. 14 is a cross-sectional view showing a state in which the intermediate body 200 shown in FIGS. 10 and 11 is cut along the XY plane, and the arrangement of the grooves G31, G32, G33, and G34 is clearly shown. ing.

  As shown in FIG. 15, the support substrate 300 bonded to the lower surface of the intermediate body 200 is a complete plate-like member having a square upper surface, and fixed electrodes E11 to E15, E21 to E25 are formed on the upper surface. , E31 to E35, E41 to E45 are arranged.

  The bottom surfaces of the four cylindrical protrusions 110, 120, 130, 140 extending downward from the force receiving body 100 side are the four cylindrical protrusions 210, 220, 230, 240 extending upward from the intermediate body 200 side. Bonded to the top surface. Here, as shown in FIG. 10, the columnar structure formed by joining the columnar projection 110 and the columnar projection 210 is referred to as a first columnar body T1, and the columnar projection 120 and the columnar projection A columnar structure formed by joining the portion 220 will be referred to as a second columnar body T2. In addition, as shown in FIG. 11, a columnar structure formed by joining the columnar projection 130 and the columnar projection 230 is referred to as a third columnar body T3, and the columnar projection 140 and the columnar projection A columnar structure formed by joining 240 is referred to as a fourth columnar body T4.

  As can be seen from the top view of FIG. 9, when the projection positions of the four columnar bodies T1 to T4 on the XY plane are considered, the first columnar body T1 has a central axis parallel to the Z axis. And the central axis of the second columnar body T2 is parallel to the Z axis, and the central axis is the X axis of the X axis. The third columnar body T3 is disposed at a position intersecting with the negative portion, and the third columnar body T3 is disposed at a position where the central axis is parallel to the Z axis and the central axis intersects with the positive portion of the Y axis. The fourth columnar body T4 is disposed at a position where the central axis is parallel to the Z axis and the central axis intersects the negative portion of the Y axis.

  Further, as shown in FIG. 10, the upper end of the first columnar body T1 is connected to the force receiving body 100 using the flexible upper end side thin portion 115 as a connecting member, and the second columnar body T2 The upper end is connected to the force receiving body 100 using the flexible upper end side thin portion 125 as a connecting member. As shown in FIG. 11, the upper end of the third columnar body T3 has flexibility. The upper end side thin portion 135 is connected to the force receiving body 100 as a connecting member, and the upper end of the fourth columnar body T4 is connected to the force receiving body 100 using the flexible upper end side thin portion 145 as a connecting member. Has been. Thus, each upper end side thin portion 115, 125, 135, 145 is connected to the power receiving body 100 at its periphery, and its lower surface central portion is connected to the upper end of each columnar body T1, T2, T3, T4. Will be. .

  On the other hand, as shown in FIG. 10, the lower surface of the first columnar body T1 is joined to the center of the lower end side thin portion 215 that functions as a connecting member, and the periphery of the lower end side thin portion 215 is interposed via the intermediate body 200. Are connected to the support substrate 300, and the lower surface of the second columnar body T2 is joined to the center of the lower end side thin portion 225 functioning as a connecting member. And connected to the support substrate 300. Similarly, as shown in FIG. 11, the lower surface of the third columnar body T3 is joined to the center of the lower end side thin portion 235 that functions as a connecting member. The lower surface of the fourth columnar body T4 is joined to the center of the lower end side thin portion 245 functioning as a connecting member, and the periphery of the lower end side thin portion 245 is an intermediate body. It is connected to the support substrate 300 through 200.

  The lower end side thin portions 215, 225, 235, and 245 are also disk-shaped members having flexibility, and a part of the intermediate body 200 supports the disk-shaped member on the support substrate 300. Is functioning as Eventually, the lower end side thin portions 215, 225, 235, and 245 are pedestal around so that the lower end side thin portions 215, 225, 235, and 245 are arranged parallel to the upper surface of the support substrate 300 at an upper position at a predetermined distance from the upper surface of the support substrate 300. The center of the upper surface is connected to the lower end of each columnar body T1, T2, T3, T4.

  In the illustrated embodiment, the power receiving body 100 is an insulating substrate (for example, a ceramic substrate), the intermediate body 200 is a conductive substrate (for example, a metal substrate such as stainless steel, aluminum, titanium, etc.), and the support substrate 300 is an insulating substrate (for example). For example, a ceramic substrate is used. Of course, the material of each part is not limited to these, For example, you may comprise the power receiving body 100 with metal substrates, such as stainless steel, aluminum, and titanium. The upper end side thin portions 115, 125, 135, and 145 and the lower end side thin portions 215, 225, 235, and 245 are configured to have flexibility by making the thickness thinner than other portions of the substrate. Part.

  In this embodiment, since the lower end side thin portions 215, 225, 235, and 245 are made of a conductive material, they have flexibility and conductivity, and themselves serve as common displacement electrodes. Fulfills the function. This is exactly the same as the configuration of the multi-axis force sensor shown in FIG.

  As shown in FIG. 15, on the upper surface of the support substrate 300, fixed electrodes E11 to E15 are formed near the lower end of the first columnar body T1, and fixed electrodes E21 to E21 are positioned near the lower end of the second columnar body T2. E25 is formed, fixed electrodes E31 to E35 are formed near the lower end of the third columnar body T3, and fixed electrodes E41 to E45 are formed near the lower end of the fourth columnar body T4. Each of these fixed electrodes is a component equivalent to the fixed electrodes E1 to E5 shown in FIG. At the center of each of the circular fixed electrodes E15, E25, E35, E45, the origin of the local coordinate system xy shown in FIG. 5 can be defined.

  Also, the lower end side thin portions 215 and 225 shown in FIG. 10 and the lower end side thin portions 235 and 245 shown in FIG. 11 are components equivalent to the thin portion 51 shown in FIG. Therefore, sensors S1 and S2 having functions equivalent to those of the multiaxial force sensor shown in FIG. 3 are formed around the groove G31 and the groove G32 shown in FIG. Sensors S3 and S4 having functions equivalent to those of the multiaxial force sensor shown in FIG. 3 are also formed around the groove G33 and the groove G34.

  Here, the sensor S1 relates to the inclination of the first columnar body T1 with respect to the X-axis direction, the inclination with respect to the Y-axis direction, and the Z-axis direction applied to the support substrate 300 from the entire first columnar body T1. The sensor S2 has a function of detecting the inclination of the second columnar body T2 with respect to the X-axis direction, the inclination with respect to the Y-axis direction, and the entire second columnar body T2. It has a function of detecting a force applied to 300 in the Z-axis direction. Similarly, the sensor S3 relates to the inclination of the third columnar body T3 in the X-axis direction, the inclination in the Y-axis direction, and the Z-axis direction applied to the support substrate 300 from the entire third columnar body T3. The sensor S4 has a function of detecting the inclination of the fourth columnar body T4 in the X-axis direction, the inclination in the Y-axis direction, and the entire fourth columnar body T4. It has a function of detecting a force applied to 300 in the Z-axis direction.

  In this way, it can be understood that the force detection device shown in FIGS. 9 to 15 is provided with the same components as the force detection device shown in FIG. That is, the plate-shaped power receiving body 100 corresponds to the power receiving body 10, the plate-shaped support substrate 300 corresponds to the support substrate 20, the columnar bodies T1 to T4 correspond to the columnar bodies 11 to 14, Sensors S1 to S4 correspond to the sensors 21 to 24, respectively. Therefore, if the detection circuit 30 is added to the structure shown in FIGS. 9 to 15, the force detection device shown in FIG. 1 can be realized.

  In practice, it is preferable to have a structure in which the peripheral contour portion of the intermediate body 200 is extended upward and the control walls 250 and 260 are formed as in the example shown in FIG. The control wall 250 is a wall that surrounds the periphery of the force receiving body 100 from four directions, and the control wall 260 is a wall that surrounds the periphery of the upper surface of the force receiving body 100 in a frame shape. In such a structure, a gap having a dimension d1 is formed between the lower surface of the force receiving body 100 and the upper surface of the intermediate body 200, and a gap having a dimension d2 is formed between the upper surface of the force receiving body 100 and the control wall 260. A gap is formed between the side surface of the force receiving body 100 and the control wall 250 with a dimension d3. Therefore, even if an excessive force is applied to the force receiving body 100, the downward, upward, and lateral displacements of the force receiving body 100 are limited to d1, d2, and d3, respectively. It is possible to prevent the structural parts such as the parts T1 to T4 from being damaged.

<<< §5. Principle of operation of specific embodiment >>>
Subsequently, the basic operation principle of the force detection device described in §4 will be described with reference to FIGS. As described in §2, this apparatus is configured to operate on the force receiving body 100 in the X-axis direction force Fx, the Y-axis direction force Fy, the Z-axis direction force Fz, the X-axis moment Mx, and the Y-axis rotation. It has a function of independently detecting six components of the force, the moment My and the moment Mz around the Z axis.

  Now, 20 fixed electrodes E11 to E15, E21 to E25, E31 to E35, E41 to E45 shown in FIG. 15 and common displacement electrodes (lower end side thin portions 215, 225, 235, and 245) opposed thereto, The 20 sets of capacitive elements constituted by the above are referred to as C11 to C15, C21 to C25, C31 to C35, and C41 to C45, respectively. C11 to C45 shown in parentheses in FIG. 15 indicate individual capacitive elements constituted by the fixed electrodes. According to the principle of the force sensor described in §3, these capacitive elements C11 to C45 have the following functions.

<Capacitance element C11>
When the first columnar body T1 is tilted in the positive direction of the X axis, the capacitance between the electrodes is increased by narrowing the electrode interval, and when the first columnar body T1 is tilted in the negative direction of the X axis, the electrode interval is increased. When the capacitance value decreases and the first columnar body T1 is tilted in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change and the first columnar shape is changed. When the body T1 is tilted in the negative Y-axis direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change.

<Capacitance element C12>
When the first columnar body T1 is tilted in the positive direction of the X axis, the capacitance value is reduced by widening the electrode interval, and when the first columnar body T1 is tilted in the negative direction of the X axis, the electrode interval is narrowed. When the capacitance value increases and the first columnar body T1 is tilted in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change and the first columnar shape is changed. When the body T1 is tilted in the negative Y-axis direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change.

<Capacitance element C13>
When the first columnar body T1 is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the first columnar body T1 is in the X-axis negative direction. When tilted, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change. When the first columnar body T1 is tilted in the positive direction of the Y axis, the electrode interval is narrowed, so that the capacitance When the value increases and the first columnar body T1 tilts in the negative Y-axis direction, the capacitance value decreases due to an increase in the electrode spacing.

<Capacitance element C14>
When the first columnar body T1 is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the first columnar body T1 is in the X-axis negative direction. When tilted, a part of the electrode interval narrows, but another part widens, so that the capacitance value does not change. When the first columnar body T1 tilts in the positive direction of the Y axis, the electrode interval widens, thereby increasing the capacitance. When the value decreases and the first columnar body T1 tilts in the negative Y-axis direction, the capacitance value increases due to the electrode interval being narrowed.

<Capacitance element C15>
When the first columnar body T1 is displaced in the positive direction of the Z axis, the capacitance between the electrodes decreases due to the electrode interval being widened. When the first columnar body T1 is displaced in the negative direction of the Z axis, the electrode interval is decreased. When the capacitance value increases and the first columnar body T1 tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is reduced, but another part is The capacitance value does not change by spreading.

<Capacitance element C21>
When the second columnar body T2 is inclined in the positive direction of the X-axis, the capacitance value is increased by narrowing the electrode interval, and when the second columnar body T2 is inclined in the negative direction of the X-axis, the electrode interval is increased. When the capacitance value decreases and the second columnar body T2 is tilted in the positive direction of the Y axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the second columnar shape When the body T2 is tilted in the negative Y-axis direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change.

<Capacitance element C22>
When the second columnar body T2 is inclined in the positive direction of the X axis, the capacitance value is reduced by increasing the electrode interval, and when the second columnar body T2 is inclined in the negative direction of the X axis, the electrode interval is decreased. When the capacitance value increases and the second columnar body T2 is tilted in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change and the second columnar shape is changed. When the body T2 is tilted in the negative Y-axis direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change.

<Capacitance element C23>
When the second columnar body T2 is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the second columnar body T2 is in the X-axis negative direction. When tilted, a part of the electrode interval narrows, but another part widens, so that the capacitance value does not change. When the second columnar body T2 tilts in the positive direction of the Y-axis, the electrode interval narrows. When the value increases and the second columnar body T2 tilts in the negative Y-axis direction, the capacitance value decreases as the electrode spacing increases.

<Capacitance element C24>
When the second columnar body T2 is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the second columnar body T2 is in the X-axis negative direction When tilted, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change. When the second columnar body T2 is tilted in the positive direction of the Y axis, the electrode interval is widened to When the value decreases and the second columnar body T2 tilts in the negative Y-axis direction, the capacitance value increases due to the electrode interval being narrowed.

<Capacitance element C25>
When the second columnar body T2 is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the second columnar body T2 is displaced in the Z-axis negative direction, the electrode interval is narrowed. When the capacitance value increases and the second columnar body T2 is inclined in the positive X-axis direction, the negative X-axis direction, the positive Y-axis direction, or the negative Y-axis direction, a part of the electrode interval is reduced, but another part is The capacitance value does not change by spreading.

<Capacitance element C31>
When the third columnar body T3 is tilted in the positive direction of the X axis, the capacitance between the electrodes is increased by narrowing the electrode interval, and when the third columnar body T3 is tilted in the negative direction of the X axis, the electrode interval is increased. When the capacitance value decreases and the third columnar body T3 is tilted in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change and the third columnar shape is changed. When the body T3 is tilted in the negative Y-axis direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change.

<Capacitance element C32>
When the third columnar body T3 is inclined in the positive direction of the X axis, the capacitance value is reduced by widening the electrode interval, and when the third columnar body T3 is inclined in the negative direction of the X axis, the electrode interval is decreased. When the capacitance value increases and the third columnar body T3 tilts in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change and the third columnar shape is changed. When the body T3 is tilted in the negative Y-axis direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change.

<Capacitance element C33>
When the third columnar body T3 is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the third columnar body T3 is in the X-axis negative direction. When tilted, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change. When the third columnar body T3 is tilted in the positive direction of the Y axis, the electrode interval is narrowed. When the value increases and the third columnar body T3 tilts in the negative Y-axis direction, the capacitance value decreases as the electrode spacing increases.

<Capacitance element C34>
When the third columnar body T3 is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the third columnar body T3 is in the X-axis negative direction. When tilted, a part of the electrode interval narrows, but another part widens, so that the capacitance value does not change. When the third columnar body T3 tilts in the positive direction of the Y-axis, the electrode spacing increases, thereby causing a capacitance. When the value decreases and the third columnar body T3 tilts in the negative Y-axis direction, the capacitance value increases due to the electrode interval being narrowed.

<Capacitance element C35>
When the third columnar body T3 is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the third columnar body T3 is displaced in the Z-axis negative direction, the electrode interval is decreased. When the capacitance value increases and the third columnar body T3 tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is reduced, but another part is The capacitance value does not change by spreading.

<Capacitance element C41>
When the fourth columnar body T4 is tilted in the positive direction of the X axis, the capacitance between the electrodes is increased by narrowing the electrode interval, and when the fourth columnar body T4 is tilted in the negative direction of the X axis, the electrode interval is increased. When the capacitance value decreases and the fourth columnar body T4 is inclined in the positive direction of the Y axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change and the fourth columnar shape is changed. When the body T4 is tilted in the negative Y-axis direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change.

<Capacitance element C42>
When the fourth columnar body T4 is inclined in the positive direction of the X axis, the capacitance value is reduced by increasing the electrode interval, and when the fourth columnar body T4 is inclined in the negative direction of the X axis, the electrode interval is decreased. When the capacitance value increases and the fourth columnar body T4 is tilted in the positive direction of the Y axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change and the fourth columnar shape is changed. When the body T4 is tilted in the negative Y-axis direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change.

<Capacitance element C43>
When the fourth columnar body T4 is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the fourth columnar body T4 is in the X-axis negative direction. When tilted, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change. When the fourth columnar body T4 is tilted in the positive direction of the Y axis, the electrode interval is narrowed, thereby causing a capacitance. When the value increases and the fourth columnar body T4 is tilted in the negative Y-axis direction, the capacitance value decreases due to the electrode interval being widened.

<Capacitance element C44>
When the fourth columnar body T4 is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change. When tilted, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change. When the fourth columnar body T4 is tilted in the positive direction of the Y axis, the electrode interval is widened to When the value decreases and the fourth columnar body T4 tilts in the negative Y-axis direction, the capacitance value increases due to the electrode interval being narrowed.

<Capacitance element C45>
When the fourth columnar body T4 is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the fourth columnar body T4 is displaced in the Z-axis negative direction, the electrode interval is narrowed. When the capacitance value increases and the fourth columnar body T4 tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is reduced, but another part is The capacitance value does not change by spreading.

  Here, in the XYZ three-dimensional coordinate system having the origin O at the position shown in FIGS. 10 and 11, the force X in the positive direction of the X axis + Fx, the force in the positive direction of the Y axis + Fy, the Z axis 20 sets having the above-described functions when a positive force + Fz, a positive moment around the X axis + Mx, a positive moment around the Y axis + My, and a positive moment around the Z axis + Mz are applied. Consider changes in the capacitance values of the capacitive elements C11 to C45.

  FIG. 17 is a side sectional view showing a deformation mode of the structure when a force + Fx in the X-axis positive direction acts on the force receiving body 100 in the force detection device shown in FIG. Similarly, FIG. 18 shows a deformation mode when a positive force + Fz in the Z axis acts, and FIG. 19 shows a deformation mode when a positive moment + My around the Y axis acts.

  On the other hand, FIG. 20 is a table showing how the capacitance values of the capacitive elements C11 to C45 change at this time. “0” indicates no change, “+ Δ” increases, and “−Δ” decreases. Show. Note that the absolute value of Δ in each column in this table does not necessarily take the same value even if the absolute value of the acting force is the same, and is determined by the shape and arrangement of each capacitive element. To a predetermined eigenvalue.

  More specifically, the absolute values of Δ described in the column of the same row for the capacitive elements having symmetry in shape and arrangement are equal to each other, but the absolute values of Δ for all the columns are mutually Not equal. For example, the absolute value of Δ shown in each column of C11 to C14, C21 to C24, C31 to C34, and C41 to C44 in the third row (+ Fz row) has symmetry in the shape and arrangement of these capacitive elements. Since they are secured, they are equal to each other, but even in the same third row, Δ in the C11 column and Δ in the C15 column have different absolute values. Further, even if Δ in the same C11 column, for example, the absolute values of the first row and the third row are different from each other.

  The reason why the capacitance value of each capacitive element changes as shown in this table is that the change modes of the structure shown in FIGS. 17 to 19 and the deformation modes of the multiaxial force sensor shown in FIGS. You can understand if you look at it.

  For example, when a force + Fx in the X-axis positive direction acts on the force receiving body 100, as shown in FIG. 17, each of the columnar bodies T1 to T4 is in the right direction (X-axis positive direction). Therefore, referring to the plan view of FIG. 15, the electrode intervals of the capacitive elements C11, C21, C31, C41 are narrowed and the capacitance value is increased, whereas the capacitive elements C12, It can be seen that the electrode spacing of C22, C32, and C42 increases and the capacitance value decreases. For other capacitive elements, the electrode spacing is partially expanded and partially decreased, so that the capacitance value does not change in total. The first row (+ Fx row) of the tables of FIGS. 20A and 20B shows such a change in capacitance value for each of the capacitive elements C11 to C45.

  On the contrary, when the force -Fx in the negative X-axis direction is applied, each of the columnar bodies T1 to T4 is inclined in the left direction (X-axis negative direction) opposite to the example shown in FIG. The relationship between the increase and decrease of the capacitance value is reversed, and the result of reversing “+” and “−” is obtained from the first row (+ Fx row) of the tables of FIGS. 20 (a) and 20 (b). Will be.

  On the other hand, when a force + Fy in the Y-axis positive direction is applied to the force receiving body 100, a phenomenon occurs in which the change mode when the force + Fx is applied is rotated by 90 ° when viewed from the top. . That is, referring to the plan view of FIG. 15, the electrode intervals of the capacitive elements C13, C23, C33, and C43 are narrowed and the capacitance value is increased, whereas the electrodes of the capacitive elements C14, C24, C34, and C44 are increased. It can be seen that the interval increases and the capacitance value decreases. For other capacitive elements, the electrode spacing is partially expanded and partially decreased, so that the capacitance value does not change in total. The second row (+ Fy row) of the tables of FIGS. 20A and 20B shows such a change in capacitance value for each of the capacitive elements C11 to C45. On the contrary, when the force -Fy in the negative Y-axis direction is applied, the relationship between the increase and decrease of the capacitance value is reversed, and the result of reversing “+” and “−” is obtained.

  Further, when a force + Fz in the positive direction of the Z-axis is applied to the force receiving body 100, each of the columnar bodies T1 to T4 is pulled against the upper surface of the support substrate 300 as shown in FIG. Since force is applied, the electrode spacing of all the capacitive elements C11 to C45 is widened, and the capacitance value is reduced. The third row (+ Fz row) in the tables of FIGS. 20A and 20B shows such a change. On the contrary, when the force −Fz in the negative Z-axis direction acts on the force receiving body 100, each of the columnar bodies T1 to T4 exerts a pressing force on the upper surface of the support substrate 300. The electrode spacing of all the capacitive elements C11 to C45 is narrowed, and the capacitance value is increased. Accordingly, a result obtained by reversing “+” and “−” with respect to the result shown in the third row (+ Fz row) of the tables of FIGS. 20A and 20B is obtained. .

  Next, let us consider a case where a moment acts on the force receiving member 100. FIG. 19 shows a change mode when a positive moment + My around the Y-axis acts on the force receiving member 100. That is, a downward pressing force −fz is applied to the support substrate 300 from the columnar body T1, and an upward pulling force + fz is applied to the support substrate 300 from the columnar body T2. Therefore, referring to the plan view of FIG. 15, the electrode spacing of the capacitive elements C11 to C15 is narrowed, and the capacitance value is increased. On the other hand, the electrode interval of the capacitive elements C21 to C25 is increased, and the capacitance value is decreased. The fifth row (+ My row) of the tables of FIGS. 20A and 20B shows such a change in capacitance value for each of the capacitive elements C11 to C45. Conversely, when a negative moment -My around the Y axis acts, the relationship between the increase and decrease of the capacitance value is reversed, and the result of reversing "+" and "-" is obtained.

  Further, when a positive moment + Mx around the X axis is applied to the force receiving member 100, a phenomenon occurs in which the change mode when the above-described moment + My is applied is rotated by 90 ° when viewed from the top. That is, a downward pressing force −fz is applied to the support substrate 300 from the columnar body T4, and an upward pulling force + fz is applied to the support substrate 300 from the columnar body T3. Therefore, the electrode interval of the capacitive elements C41 to C45 is narrowed, and the capacitance value is increased. On the other hand, the electrode interval of the capacitive elements C31 to C35 is increased, and the capacitance value is decreased. The fourth row (+ Mx row) of the tables of FIGS. 20A and 20B shows such a change in capacitance value for each of the capacitive elements C11 to C45. Conversely, when a negative moment -Mx around the X axis is applied, the relationship between the increase and decrease of the capacitance value is reversed, and the result of reversing "+" and "-" is obtained.

  Finally, let us consider a case where a moment Mz around the Z-axis acts on the force receiving body 100. First, referring to FIG. 15, when a positive moment + Mz (a counterclockwise moment on the plan view of FIG. 15) is applied to the force receiving member 100, four columnar bodies. Let us consider in which direction T1 to T4 are inclined.

  In this case, the first columnar body T1 (arranged on the fixed electrode E15 in the figure) is inclined upward in FIG. 15, the electrode interval of the capacitive element C13 is narrowed, the capacitance value is increased, and the capacitance is increased. The electrode interval of the element C14 is increased and the capacitance value is decreased. The capacitance values of the capacitive elements C11, C12, C15 do not change. The second columnar body T2 (arranged on the fixed electrode E25 in the figure) is inclined downward in FIG. 15, the electrode interval of the capacitive element C24 is narrowed, and the capacitance value is increased. The electrode spacing is increased and the capacitance value is reduced. The capacitance values of the capacitive elements C21, C22, C25 do not change. The third columnar body T3 (arranged on the fixed electrode E35 in the figure) is inclined to the left in FIG. 15, the electrode interval of the capacitive element C32 is narrowed, and the capacitance value is increased, and the capacitive element C31. The electrode interval becomes wider and the capacitance value decreases. The capacitance values of the capacitive elements C33, C34, and C35 do not change. The fourth columnar body T4 (arranged on the fixed electrode E45 in the figure) is inclined to the right in FIG. 15, the electrode interval of the capacitive element C41 is narrowed, and the capacitance value is increased, and the capacitive element C42. The electrode interval becomes wider and the capacitance value decreases. The capacitance values of the capacitive elements C43, C44, and C45 do not change.

  Eventually, when a positive moment + Mz around the Z-axis acts on the force receiving body 100, an increase / decrease result as shown in the sixth line of FIG. 20 is obtained. Further, when a negative moment -Mz around the Z-axis acts on the force receiving member 100, the relationship between the increase and decrease of the capacitance value is reversed, and the result that "+" and "-" are reversed is obtained. Will be.

  Considering that the results shown in the tables of FIGS. 20A and 20B are obtained, as the detection circuit 30, the capacitance values (here, capacitance values) of 20 sets of capacitive elements C11 to C45. If the circuit which performs the operation based on the formula shown in FIG. 21 is prepared based on the same value C11 to C45), Fx, Fy, Fz, Mx, My, Mz Six components can be obtained.

  For example, the formula Fx = (C11−C12) + (C21−C22) + (C31−C32) + (C41−C42) shown in FIG. 21 is the first row of the tables of FIGS. 20 (a) and 20 (b). Based on the result of the eye (the row of + Fx), the force is received based on the sum of the inclinations in the X-axis direction of the columnar bodies T1 to T4 detected by the first to fourth sensors S1 to S4. This means that the X-axis direction component Fx of the force acting on the body 100 can be detected. This is based on the detection principle shown in FIG.

  Further, the expression Fy = (C13−C14) + (C23−C24) + (C33−C34) + (C43−C44) shown in FIG. 21 is the second row of the tables of FIGS. 20 (a) and 20 (b). Based on the result of the eye (the row of + Fy), the force is received based on the sum of the inclinations in the Y-axis direction of the columnar bodies T1 to T4 detected by the first to fourth sensors S1 to S4. This means that the Y-axis direction component Fy of the force acting on the body 100 can be detected. This is also based on the detection principle shown in FIG.

  Further, the formula Fz = − (C15 + C25 + C35 + C45) shown in FIG. 21 is based on the results of the third row (+ Fz row) of the tables of FIGS. 20 (a) and 20 (b). This means that the Z-axis direction component Fz of the force acting on the force receiving body 100 can be detected based on the sum of the forces in the Z-axis direction of the columnar bodies T1 to T4 detected by the four sensors S1 to S4. . The leading minus sign is based on the Z axis direction.

  On the other hand, the equation Mx = (C41 + C42 + C43 + C44 + C45)-(C31 + C32 + C33 + C34 + C35) shown in FIG. 21 is based on the result of the fourth row (+ Mx row) of the tables of FIGS. A sum of forces related to the Z-axis direction of the fourth columnar body T4 detected by the fourth sensor S4 and a sum of forces related to the Z-axis direction of the third columnar body T3 detected by the third sensor S3. This means that the moment Mx around the X axis of the force acting on the force receiving body 100 can be detected based on the difference. This is based on the detection principle shown in FIG.

  Further, the equation My = (C11 + C12 + C13 + C14 + C15) − (C21 + C22 + C23 + C24 + C25) shown in FIG. 21 is based on the result of the fifth row (+ My row) of the tables of FIGS. A sum of forces in the Z-axis direction of the first columnar body T1 detected by the first sensor S1 and a sum of forces in the Z-axis direction of the second columnar body T2 detected by the second sensor S2. This means that the moment My around the Y axis of the force acting on the force receiving body 100 can be detected based on the difference. This is based on the detection principle shown in FIG.

  Finally, the equation Mz = ((C13−C14) + (C41−C42)) − ((C23−C24) + (C31−C32)) shown in FIG. 15 is expressed by the following equations (a) and (b) in FIG. Based on the result of the sixth row (+ Mz row) of the table, the inclination of the first columnar body T1 detected by the first sensor S1 in the Y-axis direction and the fourth sensor S4 The sum of the detected inclination of the fourth columnar body T4 in the X-axis direction, the inclination of the second columnar body T2 detected in the Y-axis direction detected by the second sensor S2, and the third sensor Meaning that the moment Mz around the Z-axis of the force acting on the force receiving body 100 can be detected based on the difference between the sum of the inclination in the X-axis direction of the third columnar body T3 detected in S3. doing.

  Note that the equations for obtaining the six components Fx, Fy, Fz, Mx, My, and Mz are not limited to the equations shown in FIG. 21, and there are several variations, as will be described later. For example, in the third formula (Fz formula) shown in FIG. 21, the capacitance of one capacitive element C15 is used as the force in the Z-axis direction of the first columnar body T1 detected by the first sensor S1. In contrast, in the fifth equation (My equation), similarly, the force in the Z-axis direction of the first columnar body T1 detected by the first sensor S1 is (C11 + C12 + C13 + C14 + C15) 5 The sum of the capacitance values of the two capacitive elements is used. This is because, as described in §3, there are a plurality of variations in the method for obtaining the force in the Z-axis direction using the multi-axis force sensor of the type shown in FIG.

  Therefore, for example, the third equation in FIG. 21 may be Fz = − ((C11 + C12 + C13 + C14 + C15) + (C21 + C22 + C23 + C24 + C25) + (C31 + C32 + C33 + C34 + C35) + (C41 + C42 + C43 + C44 + C45)). Similarly, the fifth expression may be My = (C15−C25). These variations will be described later as a list.

  As described above, an apparatus that can obtain six components of Fx, Fy, Fz, Mx, My, and Mz while being one force detection apparatus is extremely useful industrially. In applications such as operation control of robots and industrial machines, there is a great demand for force detection devices that can detect force and moment clearly. The force detection device shown here can be said to be a device suitable for such an application. For example, if the force detection device shown in FIG. 16 is used as a joint portion between a robot arm and a wrist, the support substrate 300 may be attached to the arm side and the force receiving body 100 may be attached to the wrist side. Then, it is possible to detect the force and moment applied to the wrist side with respect to the arm.

<<< §6. Problems in high-precision detection >>>
Now, in §5, the operation principle for obtaining six components Fx, Fy, Fz, Mx, My, and Mz is described for the embodiment having the specific structure described in §4. In this operation principle, when these six component forces act independently, the change in the capacitance value of each of the capacitive elements C11 to C45 is as shown in the tables of FIGS. 20 (a) and 20 (b). It is based on the premise that As long as this premise is established, the detected values of the six components are not affected by the interference of other components, so that the detected values of the six components can be obtained independently.

  However, in practice, in the case of the embodiment having the specific structure described in §4, it is not possible to obtain an accurate measurement value of only a necessary component in a state where interference of other axis components is completely eliminated. Of course, if the ratio of the other-axis interference component included in the measurement value is within the allowable error range, the detection based on the operation principle described in §5 is performed on the premise of the tables shown in FIGS. 20 (a) and (b). There is no hindrance to go. However, recently, a force detection device with higher measurement accuracy is desired in various fields of use, and a device for further reducing interference of other axis components is required. The present invention has been made in response to such a demand, and proposes a new technique for obtaining a more accurate detection value that eliminates interference of other axis components.

  The inventor of the present application analyzed in detail the detection values of the six components obtained when the apparatus according to the embodiment described in §4 is operated according to the principle described in §5. The fact that it was detected as part of the force component was confirmed. Specifically, in the operating principle described in §5, the moment component My around the Y axis interferes with the detection result of the force X-axis direction component Fx, and the moment component Mx around the X-axis becomes the force Y-axis. It was confirmed that the detection result of the direction component Fy interfered. The cause of such other-axis interference can be explained for the following reason.

  First, referring again to FIG. 2, let us consider the difference in the detection principle of the force Fx and the moment My. In the description using FIG. 2, as shown in FIG. 2 (b), when the force + Fx is applied to the force receiving body 10, the two columnar bodies 11 and 12 are inclined in the positive direction of the X axis. It was stated that if the degree is detected by a sensor, the value of force + Fx can be obtained. Further, as shown in FIG. 2 (c), when the moment + My acts on the force receiving body 10, a pressing force -fz is applied from the first columnar body 11 to the support substrate 20, and the second columnar body. Since a pulling force + fz is applied from 12, a value of moment + My can be obtained by detecting the force in the Z-axis direction with a sensor.

  This explanation is based on the premise that when the moment + My acts on the force receiving body 10, the two columnar bodies 11 and 12 do not incline. In fact, FIG. 2 (c) shows two columnar bodies. 11 and 12 are not inclined at all. However, in the embodiment having a specific structure as shown in §4, when the moment + My acts on the force receiving body 10, it is inevitable that the two columnar bodies 11 and 12 are inclined. Of course, the degree of inclination that occurs when the moment My acts is smaller than the degree of inclination that occurs when the force Fx acts, so if it is within the allowable error range, as shown in FIG. In addition, there is no problem even if the resulting inclination is ignored. However, when more precise accuracy is required, such a tilt cannot be ignored.

  Of course, when the moment My acts, the structure can be devised so that the inclination of the two columnar bodies 11 and 12 is as small as possible. For example, if a mechanical structure such as a link mechanism or a cam structure is incorporated in the connecting portion between the columnar bodies 11 and 12 and the force receiving body 10, an ideal as shown in FIG. It may be possible to get close to the state. However, if such a mechanical structure is incorporated, the structure becomes complicated and the cost increases, which is not preferable from a commercial viewpoint. In order to meet the demands of the industry for simplifying the structure as much as possible and reducing the cost, it is necessary to connect the columnar bodies 11 and 12 to the force receiving body 10 through a flexible member such as a thin portion. Is the best. However, if a structure in which both are connected via such a flexible member is taken, it is inevitable that the two columnar bodies 11 and 12 are inclined when the moment My acts.

  In FIG. 19 used in the description of the operating principle of §5, when the moment + My acts on the force receiving member 100, a downward pressing force −fz from the first columnar body T1 acts on the support substrate 300. In addition, a state in which an upward pulling force + fz acts from the second columnar body T2 is shown. Here, the illustrated first columnar body T1 and second columnar body T2 are not inclined at all. This corresponds to the principle diagram of FIG. 2 (c), and depicts a state in which the inclination generated in the first columnar body T1 and the second columnar body T2 is ignored.

  However, as long as a structure in which the first columnar body T1 and the second columnar body T2 are connected to the force receiving body 100 via a thin wall portion having flexibility, a moment + My acts on the force receiving body 100. It is inevitable that the first columnar body T1 and the second columnar body T2 are inclined in the positive X-axis direction. That is, the deformation mode when the moment + My acts is actually a mode as shown in FIG. 22 instead of FIG.

  Even when the deformation mode shown in FIG. 22 occurs, the downward pressing force -fz from the first columnar body T1 acts on the support substrate 300, and the upward pulling force from the second columnar body T2 The point at which + fz acts does not change, and the action of such a force is the main phenomenon. However, since the first columnar body T1 and the second columnar body T2 are also slightly inclined in the X-axis positive direction, the result of the fifth row (+ My row) in FIG. Will be inaccurate.

  That is, in the fifth row (+ My row) in FIG. 20A, the change modes of C11 to C15 are all “+ Δ”, and the change modes of C21 to C25 are all “−Δ. " This is because a deformation mode as shown in FIG. 19 occurs, so that the electrode intervals of the capacitive elements C11 to C15 are uniformly narrowed, and the electrode intervals of the capacitive elements C21 to C25 are uniformly widened. The assumption results are shown. Under such assumption, the absolute values of Δ in the columns C11 to C14 and C21 to C24 having symmetry in shape and arrangement are equal to each other.

  However, in practice, as shown in FIG. 22, the electrode spacing of the capacitive elements C11 to C15 constituting the first sensor S1 is not uniformly narrowed. Of course, as an overall trend, the electrode spacing of the capacitive elements C11 to C15 is narrower than that in the state where no force is applied, but the first columnar body T1 is inclined in the positive direction of the X axis. The narrowing of the capacitive element C11 becomes more prominent, and the narrowing of the capacitive element C12 becomes slow. Similarly, the electrode intervals of the capacitive elements C21 to C25 constituting the second sensor S2 are not uniformly widened. Of course, as an overall trend, the electrode spacing of the capacitive elements C21 to C25 is larger than that in the state where no force is applied, but the second columnar body T2 is inclined in the positive direction of the X axis. The way in which the capacitive element C22 spreads becomes more prominent, and the way in which the capacitive element C21 spreads becomes slow.

  Therefore, when the moment My acts on the force receiving body 100, Δ is a change in the capacitance value that occurs when the inclination of the first columnar body T1 and the second columnar body T2 is ignored. If the change in capacitance value caused by the inclination of the columnar body T1 and the second columnar body T2 is δ, the column C11 in the fifth row (+ My row) in FIG. “+ Δ + δ”, and the column of C12 is actually “+ Δ−δ”. About the column of C13-C15, since it is thought that the influence of the inclination of 1st columnar body T1 is canceled by a partial part, it may remain "+ (DELTA)". Similarly, the column C21 in the fifth row (+ My row) in FIG. 20A is actually “−Δ + δ”, and the column C22 is actually “−Δ−δ”. About the column of C23-C25, since it is thought that the influence of the inclination of 1st columnar body T1 is canceled by a partial part, it may remain "-(DELTA)".

  Exactly the same phenomenon occurs with respect to the third columnar body T3 and the fourth columnar body T4. That is, each column of the fifth row (+ My row) in FIG. 20B is “0”, and when the moment My is applied, the capacitive elements C31 to C35, C41 to C45. The results show that there is no change in the capacitance value, but the third columnar body T3 and the fourth columnar body T4 are not inclined even when the moment My is applied. The result is based on assumptions. However, in practice, the third columnar body T3 and the fourth columnar body T4 are inclined in the positive direction of the X-axis by the action of the moment My.

  Accordingly, when the change in the capacitance value caused by the inclination of the third columnar body T3 and the fourth columnar body T4 when the moment My acts on the force receiving body 100 is represented by δ, FIG. The column C31 in the fifth row (+ My row) is actually “0 + δ”, and the column C32 is actually “0−δ”. About the column of C33-C35, since it is thought that the influence of the inclination of 3rd columnar body T3 is canceled by a partial part, it may remain "0". Similarly, the column C41 in the fifth row (+ My row) in FIG. 20B is actually “0 + δ”, and the column C42 is actually “0−δ”. About the column of C43-C45, since it is thought that the influence of the inclination of 4th columnar body T4 is canceled by a partial part, it may remain "0".

  Although the strict handling when the moment My acts on the force receiving body 100 has been described above, the strict handling when the moment Mx acts on the force receiving body 100 is exactly the same, and FIG. Among the columns of the fourth row (+ Mx row) in the table shown in b), for the column affected by the inclination of each columnar body T1 to T4, the change amount δ of the capacitance value caused by the inclination is corrected. It is necessary to add as.

  The tables shown in FIGS. 23 (a) and 23 (b) are obtained by adding such a correction term for the change δ to the tables shown in FIGS. 20 (a) and 20 (b). A column in which the frame is surrounded by a thick line is a column to which a correction term for the change δ is added. Eventually, in the case of the embodiment having the specific structure described in §4, the original capacitance values of the capacitive elements C11 to C45 when the six components Fx, Fy, Fz, Mx, My, and Mz are applied. The change modes are as shown in the tables of FIGS. 23A and 23B, and it is necessary to obtain six component detection values on the premise of such a change mode. However, if the change δ is within the allowable error range, there is no problem even if δ = 0 in the tables of FIGS. 23 (a) and 23 (b), and the tables of FIGS. 20 (a) and 20 (b) are substituted. However, there will be no problem.

  In other words, when high-precision measurement that cannot handle the change δ as the allowable error range is required, it is necessary to treat the table shown in FIGS. 23 (a) and 23 (b). Therefore, when the tables of FIGS. 23 (a) and (b) are used instead of the tables of FIGS. 20 (a) and (b), the six components Fx, Fy, Fz, Mx, My, Let's consider how this affects the detection principle of Mz.

  In the tables of FIGS. 23 (a) and 23 (b), the capacitance elements C11 to C14, C21 to C24, C31 to C34, and C41 to C44 corresponding to the column in which the correction term of the change δ is described are all in the shape. Since the elements have symmetry in arrangement, it can be considered that the absolute values of δ described in this table are all equal. Then, even if such a correction term is added, an arithmetic expression in which the change δ is canceled by the calculation including + δ and −δ is not affected at all by the addition of the correction term.

From this point of view, if the arithmetic expressions of the six components Fx, Fy, Fz, Mx, My, and Mz shown in FIG. 21 are checked, the arithmetic expression that is affected by the addition of the correction term is an arithmetic operation that calculates Fx and Fy. It turns out that it is only a formula. FIG. 24 is a rewrite of the arithmetic expression for the six components Fx, Fy, Fz, Mx, My, and Mz shown in FIG. 12 in consideration of the correction term for the change δ. The first formula in FIG. 24 is obtained by replacing the left side Fx in the first formula in FIG. 21 with Fx ^* . The second formula in FIG. 24 is the left side Fy in the second formula in FIG. ^* Replaced by (the contents of the right side of each expression remain the same). Also, the third to sixth expressions in FIG. 24 are exactly the same as the third to sixth expressions in FIG.

The reason why the left side of the first equation in FIG. 24 is Fx ^* is that the value on the right side of this equation does not indicate the correct force Fx. For example, consider a case where a combined force including all six components Fx, Fy, Fz, Mx, My, and Mz is applied to the force receiving body of this force detection device. In this case, the capacitance values shown in the respective columns of FIGS. 23A and 23B change in the capacitive elements C11 to C45. The right side of the first equation in FIG. 24 shows the force in the X-axis direction based on the change in capacitance value shown in each column of the first row (+ Fx row) in FIGS. 23 (a) and 23 (b). The equation is intended to detect the component Fx. In the case of this example, if the right side is calculated in consideration of the capacitance value shown in each column of the first row (+ Fx row), the calculated value on the right side becomes 8Δ, so this value 8Δ is originally intended. The value to be output as the detection value.

  In this case, if there is no interference with other axis components, the detected value of the force Fx should not be affected by the other five components Fy, Fz, Mx, My, and Mz. Actually, the value on the right side of the first expression in FIG. 24 does not depend on the other four components Fy, Fz, Mx, and Mz. That is, the result of calculating the right side of the first equation in FIG. 24 based on the change in capacitance value shown in each column of the second row (+ Fy row) in FIGS. 23 (a) and 23 (b) is 0. 23 (a) and 23 (b), each column of the third row (+ Fz row), each column of the fourth row (+ Mx row), or the sixth row (+ Mz row). The result of calculating the right side of the first equation in FIG. 24 based on the change in capacitance value shown in each column is also zero. However, the result of calculating the right side of the first equation of FIG. 24 based on the change in capacitance value shown in each column of the fifth row (+ My row) is 8δ.

Eventually, the calculated value on the right side of the first equation in FIG. 24 = 8Δ + 8δ, resulting in an error 8δ with respect to Fx = 8Δ that should be originally obtained. The reason why the left side of the first equation in FIG. 24 is set to Fx ^* is that this value is not an accurate Fx value but a value of Fx + 8δ including an error. Such an error is caused by the change in each capacitance value as indicated by the balloons “+ δ” and “−δ” below each term on the right side of the first expression in FIG. This is because a change δ caused by the inclination of the columnar body in the X-axis direction caused by the action of the moment My is included.

For exactly the same reason, the calculated value on the right side of the second equation in FIG. 24 is 8Δ−8δ, resulting in an error 8δ with respect to Fy = 8Δ that should be originally obtained. The reason why the left side of the second equation in FIG. 24 is Fy ^* is that this value is not an accurate Fy value but a value of Fy-8δ including an error. Such an error is caused by the change in each capacitance value as indicated by the balloons “+ δ” and “−δ” below each term on the right side of the second expression in FIG. This is because a change δ caused by the inclination of the columnar body in the Y-axis direction caused by the action of the moment Mx is included.

As described above, among the six components Fx, Fy, Fz, Mx, My, and Mz of the force to be detected, for Fz, Mx, My, and Mz, calculations based on the third to sixth expressions in FIG. By performing this, an accurate value free from other-axis interference can be obtained. For Fx and Fy, the approximate value Fx ^* shown by the first equation in FIG. 24 is shown by the second equation. Only approximate value Fy ^* can be obtained. If the error value 8δ is within an allowable range, it can be handled approximately as Fx = Fx ^* and Fy = Fy ^*. However, when high-precision measurement is required, A device to eliminate the error is required.

<<< §7. Detection processing of each force component according to the present invention >>>
Now, in §6, it was described that the six components Fx ^* , Fy ^* , Fz, Mx, My, and Mz can be calculated by the equations shown in FIG. Here, Fx ^* and Fy ^* are inaccurate values of Fx and Fy including other-axis interference components. As described in §6, the other-axis component included in Fx ^* is the moment component My, and the other-axis component included in Fy ^* is the moment component Mx. The basic idea of the present invention is to correct other axis components My and Mx included in Fx ^* and Fy ^* based on moment components My and Mx obtained by another method.

First, FIG. 25 shows a list of variations of equations for calculating the six components Fx ^* , Fy ^* , Fz, Mx, My, and Mz shown in FIG. Each formula shown in FIG. 25 is expressed by 20 sets of capacitive elements C11 to C45 (20 fixed electrodes E11 to E45 shown in FIG. 15 and opposed to them) used in the specific embodiment described in §4. The calculation of the six components Fx ^* , Fy ^* , Fz, Mx, My, and Mz based on the capacitance values C11 to C45 of the capacitive element having a conductive lower end side thin portion) It is.

  Here, the capacitive elements C11 to C15 constitute a first sensor S1 that performs detection for the first columnar body T1, and the capacitive elements C21 to C25 perform second detection for the second columnar body T2. The capacitive elements C31 to C35 constitute a third sensor S3 that performs detection for the third columnar body T3, and the capacitive elements C41 to C45 detect for the fourth columnar body T4. A fourth sensor S4 for performing the above is configured.

  More specifically, the first sensor S1 includes a plurality of spaces formed between the lower end side thin portion 215 of the first columnar body T1 and the upper surface of the support substrate 300 facing the first sensor S1. It is comprised by the capacitive elements C11-C15. In these capacitive elements, one electrode is formed on the lower surface of the lower end thin portion 215, and the other electrodes E <b> 11 to E <b> 15 are formed on the upper surface of the support substrate 300.

  The second sensor S2 includes a plurality of capacitive elements C21 to C25 formed in a space sandwiched between the lower end side thin portion 225 of the second columnar body T2 and the upper surface of the support substrate 300 facing the second sensor S2. ing. In these capacitive elements, one electrode is formed on the lower surface of the lower end thin portion 225, and the other electrodes E <b> 21 to E <b> 25 are formed on the upper surface of the support substrate 300.

  The third sensor S3 includes a plurality of capacitive elements C31 to C35 formed in a space sandwiched between the lower end side thin portion 235 of the third columnar body T3 and the upper surface of the support substrate 300 facing the third sensor S3. ing. In these capacitive elements, one electrode is formed on the lower surface of the lower end side thin portion 235, and the other electrodes E <b> 31 to E <b> 35 are formed on the upper surface of the support substrate 300.

  The fourth sensor S4 is configured by a plurality of capacitive elements C41 to C45 formed in a space sandwiched between the lower end side thin portion 245 of the fourth columnar body T4 and the upper surface of the support substrate 300 facing the fourth sensor S4. ing. In these capacitive elements, one electrode is formed on the lower surface of the lower end side thin portion 245, and the other electrodes E <b> 41 to E <b> 45 are formed on the upper surface of the support substrate 300.

  In addition, when each lower end side thin part is comprised with the electroconductive material, since this lower end side thin part itself can be functioned as a single common electrode, it is a separate electrode on the lower surface of the lower end side thin part. There is no need to form. In the case of the specific embodiment described above, since the lower end side thin portions 215, 225, 235, 245 are made of a conductive material, these thin portions themselves function as a common electrode.

  Of course, contrary to the embodiment shown here, the lower end side thin portion is made of an insulating material, individual electrodes are formed on the lower surface of the lower end side thin portion, and the fixed electrode formed on the upper surface side of the support substrate is A physically single common electrode may be used.

In FIG. 25, six components Fx ^* and Fy ^* are represented by electrostatic capacitance values C11 to C45 (shown using the same reference numerals as the respective capacitive elements) of the 20 capacitive elements C11 to C45 constituting the sensors S1 to S4 ^. , Fz, Mx, My, and Mz, three variations are shown for each calculation.

First, as expressions for obtaining Fx ^* , Fx1 ^* = (C11−C12) + (C21−C22) + (C31−C32) + (C41−C42), Fx2 ^* = (C11−C12) + (C21−C22) Fx3 ^* = (C31−C32) + (C41−C42) are defined. The formula of Fx ^* shown in FIG. 24 corresponds to the formula of Fx1 ^* , and obtains the sum of the X-axis gradients of all four columnar bodies T1 to T4. On the other hand, the formula of Fx2 ^* is to obtain the sum of the X-axis inclinations of the two columnar bodies T1 and T2, and the formula of Fx3 ^* is the X of the two columnar bodies T3 and T4. The sum of the shaft inclinations is obtained.

Further, as expressions for obtaining Fy ^* , Fy1 ^* = (C13-C14) + (C23-C24) + (C33-C34) + (C43-C44), Fy2 ^* = (C13-C14) + (C23-C24) , Fy3 ^* = (C33−C34) + (C43−C44) are defined. The equation of Fy ^* shown in FIG. 24 corresponds to the equation of Fy1 ^* , and obtains the sum of the Y-axis gradients of all four columnar bodies T1 to T4. On the other hand, the formula of Fy2 ^* is to obtain the sum of the Y-axis inclinations of the two columnar bodies T1 and T2, and the formula of Fy3 ^* is Y of the two columnar bodies T3 and T4. The sum of the shaft inclinations is obtained.

  Next, as a formula for obtaining Fz, Fz1 = − ((C11 + C12 + C13 + C13 + C14) + (C21 + C22 + C43 + C34 + C34 + C34 + C34 + C34 + C34 + C34 + C34 + C35) , Fz3 = − (C15 + C25 + C35 + C45) are defined. The formula of Fz shown in FIG. 24 corresponds to the formula of Fz3. The equation of Fz1 is an equation for detecting a force in the Z-axis direction by using all five sets of capacitive elements constituting each sensor. On the other hand, the formula of Fz2 is a formula for detecting a force in the Z-axis direction using four sets of capacitive elements that constitute each sensor, and the formula of Fz3 is a central formula that constitutes each sensor. This is an expression for detecting a force in the Z-axis direction using a set of capacitive elements.

  As another formula for obtaining Fz, using only two columnar bodies, for example, Fz1 ′ = − ((C11 + C12 + C13 + C15) + (C21 + C22 + C23 + C24 + C25)), Fz2 ′ = − ((C11 + C12 + C13 + C14) + (C21 + C22 + C24)) Fz3 ′ = − (C15 + C25) can be used. However, in practice, it is preferable to use the above-described formulas of Fz1, Fz2, and Fz3 in order to perform stable detection.

  On the other hand, three formulas are defined as Mx1 = (C41 + C42 + C43 + C44 + C45) − (C31 + C32 + C33 + C34 + C35), Mx2 = (C41 + C42 + C43 + C44) − (C31 + C32 + C33 + C34), Mx3 = (C45−C35). The expression Mx shown in FIG. 24 corresponds to the expression Mx1 described above, and detects the force in the Z-axis direction using all the five sets of capacitive elements constituting each of the sensors S3 and S4. It is a formula. On the other hand, the expression of Mx2 is an expression for detecting a force in the Z-axis direction by using four sets of capacitive elements constituting each of the sensors S3 and S4, and the expression of Mx3 is an expression for each sensor S3. , S4 is an expression for detecting a force in the Z-axis direction by using a central set of capacitive elements constituting each of S4.

  In addition, three formulas are defined as My1 = (C11 + C12 + C13 + C14 + C15) − (C21 + C22 + C23 + C24 + C25), My2 = (C11 + C12 + C13 + C14) − (C21 + C22 + C23 + C24), My3 = (C15−C25). The My equation shown in FIG. 24 corresponds to the My1 equation described above, and detects the force in the Z-axis direction using all of the five capacitive elements constituting each of the sensors S1 and S2. It is a formula. On the other hand, the expression of My2 is an expression for detecting a force in the Z-axis direction using four sets of capacitive elements constituting each of the sensors S1 and S2, and the expression of My3 is an expression for each sensor S1. , S2 is an expression for detecting a force in the Z-axis direction using a central set of capacitive elements constituting each of S2.

  Further, Mz1 = ((C13−C14) + (C41−C42)) − ((C23−C24) + (C31−C32)), Mz2 = (C13−C14) − (C23−C24) ), Mz3 = (C41−C42) − (C31−C32) are defined. The equation of Mz shown in FIG. 24 corresponds to the equation of Mz1, and is an equation that considers the X-axis or Y-axis inclination of all four columnar bodies T1 to T4. On the other hand, the equation of Mz2 is an equation considering only the X-axis or Y-axis inclination of the two columnar bodies T1 and T2, and the equation of Mz3 is the two columnar bodies T3 and T3. This is an equation considering only the X-axis or Y-axis inclination of T4.

Now, there are variations as shown in FIG. 25 for calculating the six components Fx ^* , Fy ^* , Fz, Mx, My, and Mz based on the capacitance values C11 to C45. A desired component can be calculated by selecting an arbitrary arithmetic expression from among the variations. The formula shown in FIG. 24 is a combination of specific formulas Fx1 ^* , Fy1 ^* , Fz3, Mx1, My1, and Mz1 selected from the variations shown in FIG. Of course, various other combinations are possible in carrying out the present invention.

  If it is not necessary to obtain all six components, only necessary formulas may be selected and combined. For example, when it is sufficient to detect only the two components of moments Mx and My, the requirement is satisfied by combining the expression Mx3 = (C45−C35) and the expression My3 = (C15−C25). It will be. In this case, it is not necessary to actually provide all the 20 sets of capacitance elements C11 to C45, and it is sufficient to provide four capacitance elements C15, C25, C35, and C45.

However, when it is necessary to detect a force component Fx that does not include an error, correction that eliminates the influence of the other-axis interference of the moment component My is necessary, and thus it is necessary to detect the component My together with the component Fx ^*. . Similarly, when it is necessary to detect a force component Fy that does not include an error, correction that eliminates the influence of other-axis interference of the moment component Mx is necessary, and thus it is necessary to detect the component Mx together with the component Fy ^*. is there. In this case, a specific expression can be selected and combined from the variations shown in FIG. 25 for the detection of the component Fx ^* and the component My or the detection of the component Fy ^* and the component Mx.

Basically, the error can be corrected by subtraction that excludes the error component. For example, the value on the right side of the first expression Fx ^* in FIG. 24 is “8Δ + 8δ” as described above. Therefore, if an operation that excludes the error “8δ” is performed, an accurate value Fx (= 8Δ) can be obtained. Therefore, the calculation required for error correction is “Fx = Fx ^* −8δ”. Here, since δ is an error caused by the moment My around the Y axis, it can be obtained by generating a predetermined coefficient in the detected value of the component My. Accordingly, an arithmetic expression necessary for error correction is given by “Fx = Fx ^* −α · My”.

Here, the coefficient α is an amount that depends on the equation used to obtain the component Fx ^* and the component My, the area of the electrodes that constitute the actual capacitive element, and the like. As shown in FIG. 25, there are several variations in the arithmetic expression for obtaining the same component, and even if any expression selected from these variations is adopted, a correct value can be obtained. The “correct value” in the above does not mean an absolute value defined up to the unit of physical quantity. Therefore, no matter which formula is adopted, it is necessary to finally perform a specific scaling. The error correction arithmetic expression “Fx = Fx ^* −α · My” is an expression that takes the difference between the component Fx ^* and the component My, and therefore, it is meaningless if the scaling of both is not performed correctly. The coefficient α is a proportional coefficient for achieving this scaling consistency.

On the other hand, since the value on the right side of the second expression Fy ^* in FIG. 24 is “8Δ−8δ” as described above, an accurate value Fy that does not include an error can be obtained by performing an operation to compensate for the error “8δ”. (= 8Δ) can be obtained. Therefore, the calculation necessary for error correction is “Fy = Fy ^* + 8δ”. Here, since δ is an error caused by the moment Mx around the X axis, it can be obtained by generating a predetermined coefficient in the detected value of the component Mx. Therefore, an arithmetic expression necessary for error correction is given by “Fy = Fy ^* −β · Mx”. Here, the coefficient β is an amount that depends on the expression used to obtain the component Fy ^* and the component Mx, the area of the electrode that constitutes the actual capacitive element, and the like. It is a coefficient.

As a result, as shown in FIG. 26, the calculation formula necessary for error correction is “Fx = Fxi ^* −αij · Myj” for the force X-axis direction component Fx and “Fy” for the force Y-axis direction component Fy. = Fyi ^* −βij · Mxj ”. Here, i is a parameter (i = 1 to 3) indicating which number of the three variations shown in FIG. 25 is selected in order to calculate the component Fx ^* or Fy ^* . j is a parameter (j = 1 to 3) indicating which number of the three variations shown in FIG. 25 is selected in order to calculate the component My or Mx. The coefficient αij selects the i-th equation in order to calculate the component Fx ^*, if you select the j-th equation in order to calculate the component My, calculated values Fxi ^* and the calculated value Myj It is a proportionality constant for ensuring the consistency of scaling. Similarly, the coefficient βij is calculated when the i-th equation is selected to calculate the component Fy ^* and the j-th equation is selected to calculate the component Mx, and the calculated value Fyi ^* and the calculated value Mxj. It is a proportionality constant to ensure the consistency of scaling.

Thus, to obtain the X-axis direction component Fx of the force, first, select one of the formulas of Fxi ^* shown in FIG. 25 (determine the value of i to any one of 1 to 3), An intermediate stage value Fxi ^* is obtained, and one of the expressions Myj shown in FIG. 25 is selected (j is determined to be any one of 1 to 3) to obtain a value of Myj, and finally i, The calculation “Fx = Fxi ^* −αij · Myj” may be performed using the coefficient αij corresponding to j. Similarly, in order to obtain the Y-axis direction component Fy of the force, first, one of the expressions of Fyi ^* shown in FIG. 25 is selected (i is determined to be any one of 1 to 3), The step value Fyi ^* is obtained, one of the expressions Mxj shown in FIG. 25 is selected (the value of j is determined to be any one of 1 to 3), and the value of Mxj is obtained. The calculation “Fy = Fyi ^* −βij · Mxj” may be performed using the coefficient βij according to the above.

In the end, in order to detect all six components Fx, Fy, Fz, Mx, My, and Mz of the force, a main body of a force detection device having a specific structure as shown in FIG. 16 is prepared, and shown in FIG. Arithmetic expressions for calculating Fx ^* , Fy ^* , Fz, Mx, My, and Mz are arbitrarily selected from the variations, and the capacitance values of all 20 sets of capacitive elements C11 to C45 included in the prepared structure. Fx ^* , Fy ^* , Fz, Mx, My, and Mz may be calculated by substituting each detected value into each selected arithmetic expression. Here, the calculated Fz, Mx, My, and Mz can be output as they are as they are, but Fx ^* and Fy ^* are subjected to correction based on the above equations using the coefficients αij and βij. , Fx and Fy are output as components.

  Of course, if it is not necessary to find all six components, only the necessary equations need be selected. In this case, it is not necessary to actually provide all the 20 sets of capacitive elements C11 to C45, and it is sufficient to provide only the elements necessary for the selected arithmetic expression.

Eventually, when designing the force detection device according to the present invention, first, as the first stage process, the equations shown in FIG. 25 and FIG. 26 are defined as “candidate equations”, The operation of selecting an arithmetic expression necessary for detecting a desired force component is performed. For example, when designing a force detection device having a function for obtaining all six components, (1) Fx = Fxi ^* −αij · Myj, (2) Fy = Fyi ^* + βij · Mxj, (3) Fz = Fzi , (4) Mx = Mxi, (5) My = Myi, and (6) Mz = Mzi are selected. Here, i and j are any one of parameters 1 to 3, and a desired parameter value may be determined for each of the six arithmetic expressions. The method for obtaining the actual values of the coefficients αij and βij in these arithmetic expressions will be described in detail in §8.

  Subsequently, as a second stage process, in order to define 20 sets of capacitive elements C11 to C45 shown in FIG. 15 as “capacitance element candidates” and perform an operation based on the arithmetic expression selected in the first stage process. An operation of selecting a necessary capacitor element from the “capacitor element candidates” is performed.

  For example, when an arithmetic expression as shown in FIG. 24 is selected, it is necessary to select all of the 20 capacitive elements C11 to C45 shown in FIG. 15, but another arithmetic expression is selected. In some cases, it is not necessary to select all of the 20 capacitive elements C11 to C45. In an actual force detection device, it is sufficient to provide only the capacitance element required by such selection.

  The detection circuit 30 shown in FIG. 1 is a circuit having a function of performing calculation based on a selected arithmetic expression based on the capacitance value of the selected capacitive element and outputting each desired force component. is there. For example, the following arithmetic functions may be provided in the detection circuit 30 used in the force detection device having a function for obtaining all six components.

<Fx ^* Calculation function>
“The inclination of the first columnar body T1 in the X-axis direction, the inclination of the second columnar body T2 in the X-axis direction, the inclination of the third columnar body T3 in the X-axis direction, and the fourth columnar body T4 “Fx1 ^* ” with the inclination with respect to the X-axis direction or “Fx2 ^* with the inclination with respect to the X-axis direction of the first columnar body T1 and the inclination with respect to the X-axis direction of the second columnar body T2” or “No. gradient sum Fx3 ^* "or a calculation function for obtaining a sum Fx ^* of the inclination about the X-axis direction of the fourth columnar body T4 about 3 in the X-axis direction of the columnar body T3.

<Fy ^* Calculation function>
“The inclination of the first columnar body T1 in the Y-axis direction, the inclination of the second columnar body T2 in the Y-axis direction, the inclination of the third columnar body T3 in the Y-axis direction, and the fourth columnar body T4 the sum of the sum Fy1 ^* "or" slope and inclination about the Y-axis direction of the second columnar member T2 in the Y-axis direction of the first columnar body T1 of inclination in the Y-axis directions Fy2 ^* "or" second gradient sum Fy3 ^* "or a calculation function for obtaining a sum Fy ^* in the inclination about the Y-axis direction of the fourth columnar body T4 about 3 in the Y-axis direction of the columnar body T3.

<Fz calculation function>
The force in the Z-axis direction applied by the first columnar body T1, the force in the Z-axis direction applied by the second columnar body T2, the force in the Z-axis direction applied by the third columnar body T3, and the fourth Calculation function for obtaining the sum Fz of the force in the Z-axis direction applied by the columnar body T4 (note that the stability is slightly inferior, but the second force and the force in the Z-axis direction applied by the first columnar body T1) The sum of the force in the Z-axis direction applied by the columnar body T2 is Fz, or the force in the Z-axis direction applied by the third columnar body T3 and the Z-axis direction applied by the fourth columnar body T4 It is also possible to use Fz as the sum of the force with respect to.

<Mx calculation function>
A calculation function for obtaining a difference Mx between a force in the Z-axis direction applied by the third columnar body T3 and a force in the Z-axis direction applied by the fourth columnar body T4.

<My calculation function>
A calculation function for obtaining a difference My between the force in the Z-axis direction applied by the first columnar body T1 and the force in the Z-axis direction applied by the second columnar body T2.

<Mz calculation function>
“The sum of the inclination of the first columnar body T1 in the Y-axis direction and the inclination of the fourth columnar body T4 in the X-axis direction, the inclination of the second columnar body T2 in the Y-axis direction, and the third The difference between the sum of the inclination of the columnar body T3 in the X-axis direction and the difference Mz1 or the inclination of the first columnar body T1 in the Y-axis direction and the inclination of the second columnar body T2 in the Y-axis direction. A calculation function for obtaining either “difference Mz2” or “difference Mz3 between the inclination of the fourth columnar body T4 in the X-axis direction and the inclination of the third columnar body T3 in the X-axis direction” as the difference Mz.

<Fx calculation function>
A correction operation function based on an arithmetic expression “Fx = Fx ^* −α · My” using a predetermined coefficient α.

<Fy calculation function>
A correction operation function based on an arithmetic expression “Fy = Fy ^* + β · Mx” using a predetermined coefficient β.

  Note that a specific circuit for electrically detecting the capacitance value of each capacitive element and a specific circuit for performing an operation based on each arithmetic expression are circuits that can be realized by a known technique. Therefore, detailed description is omitted here.

<<< §8. Method for determining coefficients αij and βij >>
As described in §7, since the coefficients αij and βij are constants that function as scaling factors, they cannot be determined unless the specific structure of the actual device is determined. That is, the shape, size, dimensions, and material of each part of the apparatus as shown in FIG. 16, in particular, the shape, size, position, and distance between the counter electrodes of the electrodes E11 to E45 constituting the capacitive elements C11 to C45. Are important factors for determining the values of the coefficients αij and βij.

  Therefore, the most practical method for determining the values of the coefficients αij and βij is a method in which a prototype of the force detection device is actually manufactured and determined based on actual measurement using the prototype. Hereinafter, an example of a specific method for determining the values of the coefficients αij and βij by actual measurement using the prototype will be described.

  FIG. 27 is a side sectional view showing an example of an experimental method for determining the coefficients αij and βij shown in FIG. In the illustrated apparatus, a measuring jig 400 is attached to the apparatus main body shown in FIG. 16 actually manufactured as a prototype. As shown in the figure, the measuring jig 400 includes a connection portion 410, an upper lid portion 420, a side wall portion 430, and a flange portion 440, and constitutes a cover that covers the upper half of the apparatus body. The reason why the measurement jig 400 is attached to perform an experiment is to apply an accurate force to the force receiving body 100.

  As described above, in the embodiment described here, the XYZ three-dimensional coordinate system is positioned so that the XY plane is in the vicinity of the upper surface of the support substrate 300 and parallel to the upper surface of the support substrate 300, and The Z axis, which is positive and negative in the lower side, is defined so as to pass through the substantially central position of the upper surface of the support substrate 300. More precisely, the XYZ three-dimensional coordinate system is defined so that the XY plane is sandwiched between the four lower thin portions 215, 225, 235, 245 and the upper surface of the support substrate 300. Yes. As described in §4, the present inventor believes that it is most preferable to set the position of the XY plane of the XYZ three-dimensional coordinate system to the center position between the pair of electrodes constituting the capacitive element. Because. For this reason, the following experiment will be described by taking as an example a case where the origin O is defined at such a position.

  However, as already described, the origin O is a conceptual position and does not necessarily need to be strictly defined. Actually, if it is defined at a predetermined point near the upper surface near the center of the support substrate 300, the effect of the present invention can be obtained sufficiently in practice. Therefore, for example, an XYZ three-dimensional coordinate system in which the upper surface of the support substrate 300 is the XY plane may be defined. In this case, the obtained force detection device is a device having a function of accurately detecting six-component forces relating to each coordinate axis in such an XYZ three-dimensional coordinate system.

  Now, when a measuring jig 400 as shown in FIG. 27 is used, forces Fx, Fy, Fz in the respective axial directions of the XYZ three-dimensional coordinate system and moments Mx, My around the respective axes in the XYZ three-dimensional coordinate system are used. , Mz can be operated accurately. For example, if a wire is attached to the action point P1 at the right end of the flange portion 440 in the drawing and pulled horizontally in the right direction in the drawing, the force component + Fx can be applied. On the contrary, if a wire is attached to the action point P2 at the left end of the flange portion 440 and pulled horizontally in the left direction in the figure, the force component -Fx can be applied. On the other hand, when the force components + Fy and −Fy in the Y-axis direction are applied, an action point on the near side or the far side of the flange portion 440 that is not illustrated may be used. Since these action points are located at positions on the XY plane, the applied force components become accurate force components in the X-axis or Y-axis direction.

  In addition, if a wire is attached to the action point P3 located at the center of the upper lid part 420 and pulled vertically upward in the figure, the force component + Fz can be applied. The force component -Fz can be applied by pushing it down vertically. Of course, the forces Fx, Fy, and Fz can be applied using a plurality of action points. In this case, a plurality of action points may be set at positions having symmetry with respect to the coordinate axes.

  On the other hand, in order to apply moments Mx, My, Mz around each axis to the force receiving body 100, complementary forces (couples) may be applied to two action points having symmetry with respect to the coordinate axes. For example, in order to apply a positive moment + My around the Y axis, the wire attached to the action point P1 is pulled vertically downward in the figure, and the wire attached to the action point P2 is pulled vertically upward in the figure. What is necessary is just to make the absolute value of the force which pulls a wire equal. Of course, in this case, the illustrated dimensions r1 and r2 (distances from the origin O to the action points P1 and P2) must be equal to each other. If the direction in which the wire is pulled is interchanged between the left and right, a negative moment -My around the Y axis can be applied.

  Similarly, when the moments + Mx and -Mx around the X axis are applied, a point of action on the front side or the back side of the flange portion 440 (not shown) is used, and one of them is complementarily drawn upward and the other downward. You just need to add power. In addition, when a positive moment + Mz around the Z axis is applied, the wire attached to the action point P1 is pulled in the back direction in the drawing along the XY plane, and the wire attached to the action point P2 is taken along the XY plane. What is necessary is just to pull in the near direction of a figure, and when applying the negative moment -Mz around a Z-axis, the direction which pulls a wire should be replaced with right and left.

  If such an experiment is performed, the output of each force component is obtained by comparing the absolute value of the force actually applied to the wire with the value of each force component obtained by using each arithmetic expression shown in FIG. It is possible to scale values. Note that the absolute values of the dimensions r1 and r2 shown in the figure are also required for scaling the moment component.

Now, the main subject of this §8 is to determine the coefficients αij and βij. First, a method for determining the coefficient αij will be described. The coefficient αij is a proportional constant used for the correction calculation of “Fx = Fxi ^* −αij · Myj”, and is a detected value Myj of the moment component around the Y-axis (a value calculated by the jth calculation formula regarding My in FIG. 25). ) To cancel an error included in an inaccurate force component Fxi ^{* in the} X-axis direction (a value calculated by the i-th arithmetic expression relating to Fx ^{* in} FIG. 25).

Therefore, a prototype of a force detection device with a measurement jig 400 as shown in FIG. 27 is prepared, and only the moment component My around the Y axis is applied to the force receiving body 100 with the support substrate 300 fixed. . According to the method described above, it is possible to eliminate the action of the force components Fx, Fy, Fz and the moment components Mx, Mz, and to apply only the moment component My. In such an environment, an experiment for measuring the calculated values Fxi ^* and Myj calculated by the detection circuit 30 is performed.

Here, the values of Fxi ^* and Myj obtained when only the moment component My is applied are described as Fxi ^* (0) and Myj (0), respectively. The graph shown in the upper part of FIG. 28 shows Fxi ^* (0) and Myj (0) obtained by such an experiment. The horizontal axis of the graph indicates the magnitude of the moment My around the Y axis applied via the measurement jig 400, and the vertical axis of the graph indicates the obtained Fxi ^* (0) and Myj (0). The actual measurement value (calculated value by the detection circuit 30) is shown.

Both graphs show the magnitude of the applied moment My, and the measured values of Fxi ^* (0) and Myj (0) obtained were proportional to the magnitude of My in practical accuracy. Value. Therefore, both graphs are linear as shown. However, even for actual measurement values corresponding to the same My, the value of Fxi ^* (0) obtained is different from the value of Myj (0). For example, in the case of the graph in the figure, the actually measured value when My = Myk is Fxi ^* (0) = αi, whereas Myj (0) = αj. This is because the measurement sensitivity of the moment My according to the arithmetic expression Fxi ^* is different from the measurement sensitivity of the moment My according to the arithmetic expression Myj. .

  This sensitivity is mainly determined based on the electrode area of the capacitive element involved in the arithmetic expression, the distance between the electrodes, and the arrangement thereof. That is, the sensitivity increases as the electrode area increases, and the sensitivity increases as the interelectrode distance decreases (although in the present embodiment, the interelectrode distance is constant for all capacitive elements). Further, in the case of a capacitive element for detecting the inclination of the columnar body, the sensitivity increases as the capacitive element is located farther from the local origin.

Therefore, the coefficient αij is set to αij = Fxi ^* (0) / Myj (0) = αi / αj as shown in the middle part of FIG. In short, the ratio between the My detection sensitivity based on the arithmetic expression Fxi ^* and the My detection sensitivity based on the arithmetic expression Myj is set as the coefficient αij. Then, Fxi ^* (0) = αij · Myj (0) is established. Here, the correction arithmetic expression “Fx = Fxi ^* −αij · Myj” in FIG. 26 is replaced with the expression “Fx (0) = Fxi ^* (0) −αij · Myj () under the environment where only the moment component My acts. 0) ”and“ αij · Myj (0) ”in the second term on the right side is replaced with“ Fxi ^* (0) ”,“ Fx (0) = Fxi ^* (0) −Fxi ^* (0) = 0 ” It can be seen that the force component Fx (0) after correction in an environment in which only the moment component My is acting becomes zero.

After all, if the coefficient αij = αi / αj is set, and the component Fx is obtained by the correction arithmetic expression “Fx = Fxi ^* −αij · Myj”, the error component resulting from the moment My is completely absent in the obtained Fx value. It will not be included. Thus, an accurate force component Fx that does not include an error component can be obtained by the correction calculation formula. In the upper graph of FIG. 28, only the actual measurement value when the positive moment + My is added is shown, but actually the actual measurement value when the negative moment -My is added is also obtained. Thus, it is preferable to determine the inclinations αi and αj of each graph from both results.

The lower part of FIG. 28 shows a specific example when i = 3 and j = 3 are selected. In this case, “Fx3 ^* = (C31−C32) + (C41−C42)” is selected as the calculation formula of Fxi ^* from the calculation formulas shown in FIG. 25, and “My3 = (C15−C25) ”is selected, and a specific correction calculation formula is“ Fx = Fx3 ^* −α33 · My3 = ((C31−C32) + (C41−C42)) − as shown in the figure. α33 · (C15-C25) ”. Here, as described above, the coefficient α33 is obtained as a ratio between the slope of the graph of the actual measurement value of Fx3 ^* obtained by the experiment in which only the moment component My is applied and the slope of the graph of the actual measurement value of My3. become.

Next, a method for determining the coefficient βij will be described. The coefficient βij is a proportional constant used for the correction calculation of “Fy = Fyi ^* + βij · Mxj”, and a detected value Mxj of the moment component around the X axis (a value calculated by the jth calculation formula regarding Mx in FIG. 25). Is a coefficient for canceling out an error included in an inaccurate force component Fyi ^{* in the} Y-axis direction (a value calculated by the i-th arithmetic expression relating to Fy ^{* in} FIG. 25).

Therefore, a prototype of a force detection device with a measuring jig 400 as shown in FIG. 27 is prepared, and only the moment component Mx around the X axis acts on the force receiving body 100 with the support substrate 300 fixed. Let According to the method described above, it is possible to eliminate the action of the force components Fx, Fy, Fz and the moment components My, Mz, and to apply only the moment component Mx. In such an environment, an experiment for measuring the calculation values Fyi ^* and Mxj calculated by the detection circuit 30 is performed.

Here, the values of Fyi ^* and Mxj obtained when only the moment component Mx is applied are described as Fyi ^* (0) and Mxj (0), respectively. The graph shown in the upper part of FIG. 29 shows -Fyi ^* (0) and Mxj (0) obtained by such an experiment. In the description of the present application, since the rotation direction of the right screw when the right screw is advanced in the positive direction of the predetermined coordinate axis is defined as a positive moment around the coordinate axis, the moment component Mx is Fy ^* Appears as a negative error component in the arithmetic expression. This is why a minus sign is attached to -Fyi ^* in the graph. The horizontal axis of the graph indicates the magnitude of the moment Mx about the X axis applied via the measurement jig 400, and the vertical axis of the graph indicates the obtained −Fyi ^* (0) and Mxj ( 0) measured values (calculated values by the detection circuit 30).

Both graphs show the magnitude of the applied moment Mx, and the measured values of -Fyi ^* (0) and Mxj (0) obtained are proportional to the magnitude of Mx in practical accuracy. It becomes the value. Therefore, both graphs are linear as shown. However, even if the measured values correspond to the same Mx, the value of -Fyi ^* (0) and the value of Mxj (0) obtained are different. For example, in the case of the graph in the figure, the actual measurement value when Mx = Mxk is −Fyi ^* (0) = βi, whereas Mxj (0) = βj. This is because the measurement sensitivity of the moment Mx according to the arithmetic expression -Fyi ^* is different from the measurement sensitivity of the moment Mx according to the arithmetic expression Mxj. Become. As described above, this sensitivity is mainly determined based on the electrode area of the capacitive element involved in the arithmetic expression, the distance between the electrodes, and the arrangement thereof.

Therefore, the coefficient βij is set to βij = −Fyi ^* (0) / Mxj (0) = βi / βj as shown in the middle part of FIG. In short, the ratio between the Mx detection sensitivity based on the arithmetic expression Fyi ^* and the Mx detection sensitivity based on the arithmetic expression Mxj is set as the coefficient βij. Then, -Fyi ^* (0) = βij · Mxj (0) is established. Here, the correction arithmetic expression “Fy = Fyi ^* + βij · Mxj” in FIG. 26 is replaced with an expression “Fy (0) = Fyi ^* (0) + βij · Mxj (0) under an environment in which only the moment component Mx acts. And “βij · Mxj (0)” in the second term on the right side is replaced with “−Fyi ^* (0)”, “Fx (0) = Fxi ^* (0) −Fxi ^* (0) = 0” Thus, it can be seen that the corrected force component Fy (0) in an environment in which only the moment component Mx is acting becomes zero.

After all, if the coefficient βij = βi / βj is set and the component Fy is obtained by the correction arithmetic expression “Fy = Fyi ^* + βij · Mxj”, the obtained Fy value does not include any error component due to the moment Mx. It will not be. Thus, an accurate force component Fy that does not include an error component can be obtained by the correction calculation formula. In the upper graph of FIG. 29, only the actual measurement value when the positive moment + Mx is added is shown, but actually the actual measurement value when the negative moment -Mx is added is also obtained. Thus, it is preferable to determine the slopes βi and βj of each graph from the results of both.

The lower part of FIG. 29 shows a specific example when i = 3 and j = 3 are selected. In this case, “Fy3 ^* = (C33−C34) + (C43−C44)” is selected as the calculation formula of Fyi ^* from the calculation formulas shown in FIG. 25, and “Mx3 = (C45−C35) ”is selected, and a specific correction calculation formula is“ Fy = Fy3 ^* + β33 · Mx3 = ((C33−C34) + (C43−C44)) + β33 · (C45-C35) ". Here, as described above, the coefficient β33 is obtained as a ratio between the slope of the graph of the actual measurement value of −Fy3 ^* obtained by the experiment in which only the moment component Mx is applied and the slope of the graph of the actual measurement value of Mx3 ^. It will be.

  As described above, the method of obtaining the coefficients αij and βij by actual measurement using a prototype has been described. Of course, if a computer can simulate a mechanical phenomenon equivalent to the actual measurement value using the prototype, Alternatively, the coefficients αij and βij can be obtained by computer simulation.

<<< §9. Simplification of detection circuit >>
The detection circuit 30 used in the present invention has a function of obtaining a desired force component value by performing a calculation based on the calculation formulas shown in FIGS. Here, when each arithmetic expression of FIG. 25 is seen, it turns out that the calculation which calculates the sum of a several electrostatic capacitance value is included everywhere. Such a calculation for calculating the sum of numerical values can be performed using an analog adder or a digital calculator, but focusing on the physical property of “sum of capacitance values” The sum can be obtained by a simple method of “electrical parallel connection” without using a special arithmetic unit.

  For example, when it is necessary to obtain the sum of capacitance values “Csum = Ca + Cb” for two capacitance elements Ca and Cb, the individual capacitance values Ca and Cb are detected as analog values or digital values. Csum can be obtained by an arithmetic operation using an analog adder or a digital arithmetic unit. However, if one electrode of the two capacitive elements Ca and Cb is connected by wiring and the other electrode is also connected by wiring, and the two are connected in parallel, the capacitive element Cab connected in parallel is connected. Is equal to the sum “Csum = Ca + Cb” of the individual capacitance values Ca and Cb.

  Based on such a policy, for a plurality of capacitive elements for which the sum of capacitance values is to be calculated, the sum in the detection circuit 30 is calculated by providing wirings that are electrically connected to each other. It is possible to omit the operation to be performed.

The upper part of FIG. 30 is a top view showing wiring on the support substrate 300 when the parameter setting of i = 1 and j = 3 is performed to detect the force Fx. In this case, as shown in the lower part of the figure, the arithmetic expression to be used is “Fx = Fx1 ^* −α13 · My3”, and the specific expression for the capacitance value is “Fx = (C11−C12) +”. (C21−C22) + (C31−C32) + (C41−C42) −α13 · (C15−C25) ”. When this equation is rewritten, “Fx = (C11 + C21 + C31 + C41) − (C12 + C22 + C32 + C42) −α13 · (C15−C25)”. In this equation, “C11 + C21 + C31 + C41” in the first term on the right side can be obtained by connecting the four capacitive elements C11, C21, C31, C41 in advance so as to be connected in parallel without using a special arithmetic unit. It can be obtained as the overall capacitance value of the connected capacitive elements. Similarly, “C12 + C22 + C32 + C42” in the second term on the right side can also be connected in parallel without using a special arithmetic unit if the four capacitive elements C12, C22, C32, C42 are wired in advance. It can be obtained as the overall capacitance value of the capacitive element.

  Here, if the coefficient α13 = 1, this calculation becomes simpler. That is, if the coefficient α13 = 1, the above equation becomes “Fx = (C11 + C21 + C31 + C41 + C25) − (C12 + C22 + C32 + C42 + C15)”, so that the five capacitive elements C11, C21, C31, C41, and C25 are wired in advance. The five capacitive elements C12, C22, C32, C42, and C15 may be wired in advance so as to be connected in parallel.

  The upper part of FIG. 30 shows such wiring. That is, for the fixed electrode on the support substrate 300 side, E11, E21, E31, E41, E25 are connected to the terminal Tfx1, and E12, E22, E32, E42, E15 are connected to the terminal Tfx2. Although not shown in FIG. 30, conductive lower end side thin portions 215, 225, 235, and 245 are provided as counter electrodes for these fixed electrodes, and these are intermediates having conductivity. 200, the capacitance value between the intermediate body 200 and the terminal Tfx1 corresponds to the sum of “C11 + C21 + C31 + C41 + C25”, and the capacitance value between the intermediate body 200 and the terminal Tfx2 is This corresponds to the sum of “C12 + C22 + C32 + C42 + C15”.

  Here, if the intermediate body 200 is connected to the ground terminal (practically, it is preferable to fix the potential of the intermediate body 200 to the ground potential in this manner), the end result is that between the terminal Tfx1 and the ground terminal. By simply obtaining the difference between the capacitance value and the capacitance value between the terminal Tfx2 and the ground terminal, the detection value of the force Fx can be obtained, and the calculation burden on the detection circuit 30 is greatly reduced. The That is, the calculation for obtaining the sum of the capacitance values included in the calculation formula can be omitted by parallel connection of the capacitive elements, and the multiplication with the coefficient α13 included in the calculation formula is set to the coefficient α13 = 1. Can be omitted.

  Incidentally, the coefficient α13 is a constant determined based on the area and arrangement of the fixed electrodes and the distance between the counter electrodes as described above. Therefore, the coefficient α13 = 1 can be set by adjusting these factors. In the case of the embodiment described here, since the distance from the counter electrode is constant, the setting of the coefficient α13 = 1 can be substantially realized by adjusting the area or arrangement of the fixed electrode. Specifically, in FIG. 30, the individual areas of the disk-shaped fixed electrodes E15 and E25 are A1, and the individual areas of the sector-shaped fixed electrodes E11, E12, E21, E22, E31, E32, E41, and E42. Assuming A2, the larger α1 is, the smaller the coefficient α13 is (because αj is larger in the upper graph of FIG. 28, αij is smaller), and the smaller is A1, the larger the coefficient α13 is. Become.

  The areas A1 and A2 for setting the coefficient α13 = 1 can be determined by trial and error using a prototype. For example, it is assumed that the result shown in the upper graph of FIG. 28 is obtained as a result of actual measurement using a prototype, and the result of αij = 1/3 is obtained. In this case, it is only necessary to change the area A1 to the current 1/3 times or to correct the area A2 to the current 3 times. Therefore, for example, if the design of the diameters of the disk-shaped fixed electrodes E15 and E25 is changed to 1 / √3, the coefficient α13 = 1 can be set.

  Of course, in practice, even if such a design change is made, there may be cases where an accurate result of the coefficient α13 = 1 cannot be obtained due to various factors, but in practice, trial and error are repeated several times. Therefore, it is possible to design to satisfy the coefficient α13 = 1 with the accuracy required for measurement. Alternatively, as described above, if computer simulation is used in combination, the number of trial and error can be reduced.

The upper part of FIG. 31 is a top view showing wiring on the support substrate 300 when the parameter setting of i = 1 and j = 3 is performed in order to detect the force Fy. In this case, as shown in the lower part of the figure, an arithmetic expression to be used is “Fy = Fy1 ^* + β13 · Mx3”, and a specific expression for the capacitance value is “Fy = (C13−C14) + ( C23−C24) + (C33−C34) + (C43−C44) + β13 · (C45−C35) ”. Again, this calculation is simpler if the coefficient β13 = 1 can be set. That is, if the coefficient β13 = 1, the above equation becomes “Fy = (C13 + C23 + C33 + C43 + C45) − (C14 + C24 + C34 + C44 + C35)”, so that the five capacitance elements C13, C23, C33, C43, and C45 are wired in advance. The five capacitive elements C14, C24, C34, C44, and C35 may be wired in advance so as to be connected in parallel.

  The upper part of FIG. 31 shows such wiring. That is, for the fixed electrode on the support substrate 300 side, E13, E23, E33, E43, E45 are connected to the terminal Tfy1, and E14, E24, E34, E44, E35 are connected to the terminal Tfx2. As described above, if the lower end side thin portions 215, 225, 235, and 245, which serve as counter electrodes for these fixed electrodes, are grounded via the intermediate body 200, the electrostatic capacitance between the terminal Tfy1 and the ground terminal is eventually obtained. Only by obtaining the difference between the capacitance value and the capacitance value between the terminal Tfy2 and the ground terminal, the detection value of the force Fy can be obtained, and the calculation burden on the detection circuit 30 is greatly reduced.

  The setting method of each capacitive element for setting the coefficient β13 = 1 is exactly the same as the setting method for setting the coefficient α13 = 1. Specifically, in FIG. 31, each area of the disk-shaped fixed electrodes E35 and E45 is A1, and each area of the fan-shaped fixed electrodes E13, E14, E23, E24, E33, E34, E43, and E44 is Assuming A2, the larger the A1, the smaller the coefficient β13 (because βj in the graph in the upper part of FIG. 29 becomes larger, βij becomes smaller), and the smaller the A1, the larger the coefficient β13 becomes. Become.

  FIG. 32 is a top view showing wiring on the support substrate 300 when the parameter setting i = 3 is performed in order to detect the force Fz. In this case, as shown in the lower part of the figure, the arithmetic expression to be used is “Fz = − (C15 + C25 + C35 + C45)”. Therefore, if the five capacitive elements C15, C25, C35, and C45 are wired in advance so as to be connected in parallel, the addition process by the detection circuit 30 can be omitted.

  FIG. 32 shows such wiring. That is, E15, E25, E35, E45 are connected to the terminal Tfz for the fixed electrode on the support substrate 300 side. As described above, if the lower end side thin portions 215, 225, 235, and 245, which are counter electrodes to these fixed electrodes, are grounded via the intermediate body 200, the electrostatic capacitance between the terminal Tfz and the ground terminal is eventually obtained. Only by obtaining the capacitance value, the detection value of the force Fz can be obtained, and the calculation burden on the detection circuit 30 is greatly reduced.

  FIG. 33 is a top view showing wiring on the support substrate 300 when the parameter setting i = 2 is performed in order to detect the moment Mx. In this case, as shown in the lower part of the figure, the arithmetic expression to be used is “Mx = (C41 + C42 + C43 + C44) − (C31 + C32 + C33 + C34)”. Therefore, if the four capacitive elements C41, C42, C43, and C44 are wired in advance to be connected in parallel, and the four capacitive elements C31, C32, C33, and C34 are wired in advance to be connected in parallel, the detection circuit 30 The addition process by can be omitted.

  FIG. 33 shows such wiring. That is, for the fixed electrode on the support substrate 300 side, E31, E32, E33, E34 are connected to the terminal Tmx1, and E41, E42, E43, E44 are connected to the terminal Tmx2. As described above, if the lower end side thin portions 235 and 245 serving as counter electrodes to these fixed electrodes are grounded via the intermediate body 200, the capacitance value between the terminal Tmx1 and the ground terminal is eventually obtained. Only by obtaining the difference between the capacitance value between the terminal Tmx2 and the ground terminal, the detection value of the moment Mx can be obtained, and the calculation load of the detection circuit 30 is greatly reduced.

  FIG. 34 is a top view showing the wiring on the support substrate 300 when the parameter setting of i = 3 is performed in order to detect the moment My. In this case, as shown in the lower part of the figure, the arithmetic expression to be used is “My = C15−C25”. In this case, since addition operation is unnecessary, E15 may be connected to the terminal Tmy1 and E25 may be connected to the terminal Tmy2 as illustrated. If the lower end side thin portions 215 and 225 that serve as counter electrodes for these fixed electrodes are grounded via the intermediate body 200, the capacitance value between the terminal Tmy1 and the ground terminal, the terminal Tmy2 and the ground terminal The detected value of the moment My can be obtained by obtaining the difference between the capacitance values of the two.

  FIG. 35 is a top view showing wiring on the support substrate 300 when the parameter setting of i = 1 is performed in order to detect the moment Mz. In this case, as shown in the lower part of the figure, the arithmetic expression to be used is “Mz = (C13 + C24 + C32 + C41) − (C14 + C23 + C31 + C42)”. Therefore, if the four capacitive elements C13, C24, C32, and C41 are wired in advance and the four capacitive elements C14, C23, C31, and C42 are wired in advance, the detection circuit 30 The addition process by can be omitted.

  FIG. 35 shows such wiring. That is, for the fixed electrodes on the support substrate 300 side, E13, E24, E32, E41 are connected to the terminal Tmz1, and E14, E23, E31, E42 are connected to the terminal Tmz2. As described above, if the lower end side thin portions 215, 225, 235, and 245, which are opposed electrodes to these fixed electrodes, are grounded via the intermediate body 200, the electrostatic capacitance between the terminal Tmz1 and the ground terminal is eventually obtained. Only by obtaining the difference between the capacitance value and the capacitance value between the terminal Tmz2 and the ground terminal, the detection value of the moment Mz can be obtained, and the calculation burden on the detection circuit 30 is greatly reduced.

In this way, among the capacitive elements that are actually formed, the wirings that are electrically connected in parallel with each other for the plurality of capacitive elements that are the targets for calculating the sum of the capacitance values in the arithmetic expression to be used As a result, the addition in the detection circuit 30 can be omitted. As for Fxi only moment around the Y axis is obtained in an environment which acts ^* values ^Fxi * (0) and MYJ value ^{Myj (0), Fxi * (} 0) = Myj (0) As is established, If the capacitive element used for calculating Fxi ^{* and} the capacitive element used for calculating Myj are set, the coefficient αij = 1 can be set, and the multiplication in the detection circuit 30 can be omitted. Similarly, the value of only the moment about the X-axis Fyi obtained in an environment which acts ^{* Fyi} * (0) and MXJ value ^{Mxj (0), -Fyi * (} 0) = Mxj (0) so that holds In addition, if the capacitive element used for calculating Fyi ^{* and} the capacitive element used for calculating Mxj are set, the coefficient βij = 1 can be set, and the multiplication in the detection circuit 30 can be omitted. .

<<< §10. Actual electrode configuration >>
Incidentally, in FIGS. 30 to 35, wirings for obtaining six force components Fx, Fy, Fz, Mx, My, and Mz are shown separately, but force detection having a function of detecting all six components is shown. In the case of a device, a plurality of wirings cannot be performed on the same electrode. For example, the electrode E13 shown in FIG. 31 is connected to the terminal Tfy1, and the electrode E13 shown in FIG. 35 is connected to the terminal Tmz1, but these two wirings are performed simultaneously on the same electrode E13. As a result, the terminal Tfy1 and the terminal Tmz1 are short-circuited via the electrode E13, and a correct detection result cannot be obtained.

  Therefore, when a plurality of capacitive elements are connected in parallel by wiring according to the method described in §9, when capacitance values with the same sign are used in a plurality of different expressions, they are physically separated. It is necessary to provide a capacitive element. In the case of the above-described example, two independent electrodes functioning as the electrode E13 may be provided, one connected to the terminal Tfy1 and the other connected to the terminal Tmz1.

  FIG. 36 is a plan view showing a basic example of electrode arrangement for sensor configuration according to the basic embodiment described so far. As shown, the origin O of the xy local coordinate system is defined at the center position, fan-shaped fixed electrodes E1, E2, E3, E4 are arranged on the x-axis and the y-axis, and the position of the origin O A disk-shaped fixed electrode E5 is disposed on the surface. The hatching in FIGS. 36 to 40 and 42 is for clearly showing the shape of each electrode, and does not show a cross section.

  As already described in §3, the fixed electrode E1 is an x-axis positive electrode used for detecting the inclination of the columnar body in the x-axis direction, and is formed in a region where the x-coordinate value in the local coordinate system is positive. Has been. The fixed electrode E2 is an x-axis negative side electrode used for detecting the inclination of the columnar body in the x-axis direction, and is formed in a region where the x-coordinate value in the local coordinate system is negative. Here, the electrodes E1 and E2 themselves have a shape that is line-symmetric with respect to the x-axis. Moreover, when attention is paid to an electrode group composed of the electrodes E1 and E2, the electrode group has a shape that is line-symmetric with respect to the y-axis.

  Similarly, the fixed electrode E3 is a y-axis positive electrode that is used to detect the inclination of the columnar body in the y-axis direction, and is formed in a region where the y-coordinate value in the local coordinate system is positive. The fixed electrode E4 is a y-axis negative electrode used for detecting the inclination of the columnar body in the y-axis direction, and is formed in a region where the y-coordinate value in the local coordinate system is negative. Here, the electrodes E3 and E4 themselves have a shape that is line-symmetric with respect to the y-axis. Moreover, when attention is paid to an electrode group including the electrodes E3 and E4, the electrode group has a shape that is line-symmetric with respect to the x-axis.

  On the other hand, the fixed electrode E5 is a Z-axis displacement detection electrode used for detecting a force in the Z-axis direction applied to the support substrate from the entire columnar body. The electrode E5 itself has a shape that is line symmetric with respect to both the x-axis and the y-axis.

  Such coordinate axis symmetry of each electrode is important in the sense of preventing other-axis interference as described above. Even if such coordinate axis symmetry is not ensured, it is theoretically possible to perform the function as the detector constituting the sensor of the present invention, but the detection value is complicated by multiplying by a coefficient. This is not practically preferable because it requires a special treatment. In other words, as long as it has such coordinate axis symmetry, the shape and arrangement of each electrode are not limited to those illustrated in FIG.

  FIG. 37 is a plan view showing a first modification of the electrode arrangement for the sensor configuration. Here, the electrodes E1a and E1b perform the same function as the electrode E1 of FIG. 36, and the electrodes E2a and E2b perform the same function as the electrode E2 of FIG. However, the combination constituting the detector for detecting the inclination of the columnar body in the x-axis direction is the electrodes E1a and E2a or the electrodes E1b and E2b (the electrode group constituted by the combination is line-symmetric with respect to the y-axis. Become). Of course, it is theoretically possible to form a detector for the inclination of the columnar body in the x-axis direction by a combination of E1a and E2b or a combination of electrodes E1b and E2a, but symmetry is not ensured. Therefore, it is necessary to perform a process such as multiplying the detected capacitance value by a coefficient corresponding to the area of each electrode.

  Similarly, the electrodes E3a and E3b perform the same function as the electrode E3 in FIG. 36, and the electrodes E4a and E4b perform the same function as the electrode E4 in FIG. Also in this case, the combination constituting the detector for detecting the inclination of the columnar body in the y-axis direction is practically the electrode E3a so that the electrode group constituting the detector is axisymmetric with respect to the x-axis. And E4a, or electrodes E3b and E4b.

  Electrodes E5a and E5b perform the same function as electrode E5 in FIG. That is, a detector that detects the force in the Z-axis direction applied to the support substrate from the entire columnar body is configured. The electrodes E5a and E5b both satisfy the condition of a shape that is line symmetric with respect to both the x axis and the y axis.

  After all, if the electrode configuration shown in FIG. 37 is adopted, two sets of electrodes each having the same function as the electrodes E1 to E5 shown in FIG. 36 can be obtained. Of course, a configuration in which three or more sets of electrodes are obtained is also possible. As described above, a plurality of sets of electrodes having the same function can be provided as necessary. Therefore, when a plurality of capacitive elements are connected in parallel by wiring, the capacitance values with the same sign are expressed by a plurality of different expressions. When used, it is possible to physically provide separate capacitive elements, and it is possible to provide independent wiring to the individual electrodes constituting these separate capacitive elements. Become.

  For example, when it is necessary to connect the electrode E13 to the terminal Tfy1 to perform the wiring shown in FIG. 31 and to connect the same electrode E13 to the terminal Tmz1 to perform the wiring shown in FIG. If the electrode E3a shown is connected to the terminal Tfy1 and the electrode E3b shown in FIG. 37 is connected to the terminal Tmz1, the terminal Tfy1 and the terminal Tmz1 are not short-circuited. Of course, in this case, the electrode E4a shown in FIG. 37 is connected to the terminal Tfy2, and the electrode E4b shown in FIG. 37 is connected to the terminal Tmz2, so that symmetry about the x axis can be ensured.

  As described above, an example in which a plurality of sets of electrodes having the same functions as those of the individual electrodes E1 to E5 shown in FIG. 36 are provided has been described. On the contrary, one electrode is configured as an assembly of a plurality of partial electrodes. You can also. For example, FIG. 38 is a plan view showing a second modification of the electrode arrangement for sensor configuration. Here, electrode configurations similar to those in FIG. 36 are shown, but these electrode configurations can be associated with the electrodes E1 to E5 shown in FIG. 36 as follows, for example.

  That is, the assembly of the pair of partial electrodes E1-1 and E1-2 shown in FIG. 38 is handled as the electrode E1 shown in FIG. 36, and the pair of partial electrodes E2-1 and E2 shown in FIG. -2 is handled as the electrode E2 shown in FIG. 36, and the assembly of the pair of partial electrodes E3-1 and E3-2 shown in FIG. 38 is handled as the electrode E3 shown in FIG. The assembly of the pair of partial electrodes E4-1 and E4-2 shown in FIG. 36 is handled as the electrode E4 shown in FIG. 36, and the assembly of the pair of partial electrodes E5-1 and E5-2 shown in FIG. A body or an assembly of a pair of partial electrodes E5-3 and E5-4 is handled as an electrode E5 shown in FIG.

  These partial electrodes alone do not maintain symmetry with respect to the coordinate axis, but as a plurality of aggregates, symmetry with respect to the coordinate axis is maintained. For example, the electrode E1-1 alone is not a figure having symmetry with respect to the x axis, but the aggregate of the pair of partial electrodes E1-1 and E1-2 has a figure having symmetry with respect to the x axis. Become. Similarly, the partial electrode E5-1 alone has symmetry with respect to the x-axis, but does not have symmetry with respect to the y-axis. However, the assembly of the pair of partial electrodes E5-1 and E5-2 has symmetry with respect to both the x-axis and the y-axis.

  Of course, the above association is merely an example, and various other associations are possible. For example, an assembly composed of eight partial electrodes E1-1, E1-2, E2-1, E2-2, E3-1, E3-2, E4-1, and E4-2 has an x-axis and a y-axis. Since both have symmetry, it can be handled as an electrode E5 shown in FIG.

  The same applies to the electrode configuration shown in FIG. For example, the electrode E1a in FIG. 37 alone can be handled as the electrode E1 shown in FIG. 36, and the electrode E2a in FIG. 37 alone can be handled as the electrode E2 shown in FIG. Since the assembly of the electrodes E1a and E2a has symmetry with respect to both the x-axis and the y-axis, it can be handled as an electrode E5 shown in FIG.

  In short, it is possible to configure one electrode constituting a specific capacitive element by an assembly of a plurality of partial electrodes arranged apart from each other, and by using such partial electrodes, electrodes of necessary capacitive elements can be formed. If this is configured, the degree of freedom of the electrode configuration pattern becomes extremely wide.

  In addition, although all the electrodes illustrated so far were a figure based on a circle, of course, the shape of the electrode is not necessarily limited to that based on a circle. FIG. 39 is a plan view showing a third modification of the electrode arrangement for sensor configuration. In this modification, the shape of each of the electrodes E1a to E5b shown in FIG. 37 is changed from a figure based on a circle to a figure based on a rectangle. Thus, even when the electrode configuration is made of a figure based on a rectangle, the symmetry with respect to the coordinate axis is maintained as it is.

  Finally, an example of an electrode configuration that seems to be optimal for a force detection device that can detect all six components Fx, Fy, Fz, Mx, My, and Mz of force by using the degree of freedom of the electrode configuration pattern. Let me mention. In fact, the coefficients α33 and β23 necessary for calculating the components Fx and Fy can be set to 1 by such an electrode configuration pattern.

  FIG. 40 is a top view of a support substrate 300 showing a first example of such an electrode configuration, and FIG. 41 is a diagram showing a wiring method of individual electrodes in this electrode configuration. Symbols attached to the respective electrodes indicate correspondences with the electrodes E11 to E45 shown in FIG. 15, and the following English letters with parentheses (Fx, Fy, Fz, Mx, My, Mz) Indicates which of the six components of force is used for detection. The hatching of each electrode is a hatching pattern corresponding to these six components Fx, Fy, Fz, Mx, My, and Mz. That is, the hatched electrode is an electrode used for detecting force components Fx, Fy, and Fz (coarse points indicate Fx, fine points indicate Fy, and thick points indicate Fz), and hatched hatching. Are applied to detection of moment components Mx, My, and Mz (the upper right lower left oblique line is Mx, the upper left lower right oblique line is My, and the mesh oblique line is Mz). To aid visual understanding, FIG. 41 also shows the corresponding hatch pattern.

  FIG. 41 shows the calculation formulas (specific calculation formulas selected by parameters i and j from the calculation formulas shown in FIG. 25) used for detecting each component, together with the wiring of these electrodes. .

First, for the component Fx, i = 3 and j = 3 are set, and an arithmetic expression “Fx = Fx3 ^* −α33 · My3” is selected. Here, in the electrode pattern shown in FIG. 40, α33 = 1, so the equation using the actual capacitance value is “Fx = (C31 + C41 + C25) − (C32 + C42 + C15)”. Therefore, as shown in the figure, the electrodes E31 (Fx), E41 (Fx), and E25 (Fx) are wired to the terminal Tfx1, and the electrodes E32 (Fx), E42 (Fx), and E15 (Fx) are wired to the terminal Tfx2. The component Fx can be obtained by the difference between the electrical signals generated at both terminals.

By such a method, the component Fx is obtained by detecting the inclination of the third columnar body T3 in the X-axis direction based on the difference between signals generated at the pair of electrodes E31 (Fx) and E32 (Fx). The inclination of the fourth columnar body T4 in the X-axis direction is detected based on the difference between the signals generated at the pair of electrodes E41 (Fx) and E42 (Fx), and a component Fx ^{* including an} error is detected by the sum of these inclinations. This is because the obtained error (other-axis interference of the component My) is canceled by the difference between the signals generated at the pair of electrodes E15 (Fx) and E25 (Fx).

For the component Fy, i = 2 and j = 3 are set, and an arithmetic expression “Fy = Fy2 ^* + β23 · Mx3” is selected. Again, since β23 = 1 in the electrode pattern shown in FIG. 40, the formula using the actual capacitance value is “Fy = (C13 + C23 + C45) − (C14 + C24 + C35)”. Therefore, as shown in the drawing, the electrodes E13 (Fy), E23 (Fy), and E45 (Fy) are wired to the terminal Tfy1, and the electrodes E14 (Fy), E24 (Fy), and E35 (Fy) are wired to the terminal Tfy2. The component Fy can be obtained by the difference between the electrical signals generated at both terminals.

By such a method, the component Fy is obtained by detecting the inclination of the first columnar body T1 in the Y-axis direction based on the difference between signals generated at the pair of electrodes E13 (Fy) and E14 (Fy). The inclination of the second columnar body T2 in the Y-axis direction is detected based on the difference between the signals generated at the pair of electrodes E23 (Fy) and E24 (Fy), and a component Fy ^{* including an} error is detected by the sum of these inclinations. This is because the obtained error (other-axis interference of the component Mx) is canceled out by the difference between the signals generated at the pair of electrodes E35 (Fy) and E45 (Fy).

  For the component Fz, i = 3 is set, and an arithmetic expression “Fz = Fz3” is selected, and an expression using an actual capacitance value is “Fz = − (C15 + C25 + C35 + C45)”. Therefore, as shown in the figure, if the electrodes E15 (Fz), E25 (Fz), E35 (Fz), and E45 (Fz) are wired to the terminal Tfz (−), the sign of the electric signal generated at the terminal Tfz (−) is reversed. By doing so, the component Fz can be obtained.

  For the component Mx, i = 3 is set, and an arithmetic expression “Mx = Mx3” is selected, and an expression using an actual capacitance value is “Mx = C45−C35”. Therefore, as shown in the drawing, if the electrode E35 (Mx) is wired to the terminal Tmx1 and the electrode E45 (Mx) is wired to the terminal Tmx2, the component Mx can be obtained by the difference between the electrical signals generated at both terminals.

  For the component My, i = 3 is set, and an arithmetic expression “My = My3” is selected, and an expression using an actual capacitance value is “My = C15−C25”. Therefore, as shown in the drawing, if the electrode E15 (My) is wired to the terminal Tmy1 and the electrode E25 (My) is wired to the terminal Tmy2, the component My can be obtained due to the difference between the electrical signals generated at both terminals.

  For the component Mz, the calculation formula “Mz = Mz1” is selected by setting i = 1, and the formula using the actual capacitance value is “Mz = (C13 + C24 + C32 + C41) − (C14 + C23 + C31 + C42)”. Become. Therefore, as illustrated, the electrodes E13 (Mz), E24 (Mz), E32 (Mz), and E41 (Mz) are wired to the terminal Tmz1, and the electrodes E14 (Mz), E23 (Mz), E31 (Mz), and E42 are connected. If (Mz) is wired to the terminal Tmz2, the component Mz can be obtained by the difference between the electrical signals generated at both terminals.

  FIG. 42 is a top view of the support substrate 300 showing a second example of an electrode configuration that seems to be optimal for a force detection device capable of detecting all six components Fx, Fy, Fz, Mx, My, and Mz of force. FIG. 43 is a diagram showing a wiring method of individual electrodes in this electrode configuration. The reference numerals attached to the respective electrodes indicate the correspondence with the electrodes E11 to E45 shown in FIG. 15, and the following English letters with parentheses (Fx, Fy, Fz, Mx, My, Mz) It shows which of the six components of force the electrode is used for detection. Further, the meaning of hatching of each electrode is the same as that in the first example. To aid in visual understanding, FIG. 43 also shows the corresponding hatch pattern.

First, for the component Fx, i = 3 and j = 3 are set, and an arithmetic expression “Fx = Fx3 ^* −α33 · My3” is selected. Here, in the electrode pattern shown in FIG. 42, α33 = 1, so the formula using the actual capacitance value is “Fx = (C31 + C41 + C25) − (C32 + C42 + C15)”. Therefore, as shown, the electrodes E31 (Fx), E41 (Fx), E25-1 (Fx), E25-2 (Fx) are wired to the terminal Tfx1, and the electrodes E32 (Fx), E42 (Fx), E15- If 1 (Fx) and E15-2 (Fx) are wired to the terminal Tfx2, the component Fx can be obtained by the difference between the electrical signals generated at both terminals.

  Here, the electrodes E15-1 (Fx) and E15-2 (Fx) are partial electrodes, respectively, and the aggregate of both functions as the electrode E15 (Fx). Similarly, the electrodes E25-1 (Fx) and E25-2 (Fx) are partial electrodes, respectively, and the aggregate of both functions as the electrode E25 (Fx).

By such a method, the component Fx is obtained by detecting the inclination of the third columnar body T3 in the X-axis direction based on the difference between signals generated at the pair of electrodes E31 (Fx) and E32 (Fx). The inclination of the fourth columnar body T4 in the X-axis direction is detected based on the difference between the signals generated at the pair of electrodes E41 (Fx) and E42 (Fx), and a component Fx ^{* including an} error is detected by the sum of these inclinations. The error (the other-axis interference of the component My) is obtained, and the electrode E15 (Fx) [actually, an assembly of the partial electrodes E15-1 (Fx) and E15-2 (Fx)] and the electrode E25 (Fx This is because the difference is caused by the difference in signal generated between the partial electrodes E25-1 (Fx) and E25-2 (Fx).

For the component Fy, i = 2 and j = 3 are set, and an arithmetic expression “Fy = Fy2 ^* + β23 · Mx3” is selected. Again, β23 = 1 in the electrode pattern shown in FIG. 42, so the equation using the actual capacitance value is “Fy = (C13 + C23 + C45) − (C14 + C24 + C35)”. Therefore, as shown, the electrodes E13 (Fy), E23 (Fy), E45-1 (Fy), E45-2 (Fy) are wired to the terminal Tfy1, and the electrodes E14 (Fy), E24 (Fy), E35- If 1 (Fy) and E35-2 (Fy) are wired to the terminal Tfy2, the component Fy can be obtained by the difference between the electrical signals generated at both terminals.

  Here, the electrodes E35-1 (Fy) and E35-2 (Fy) are partial electrodes, respectively, and the aggregate of both functions as the electrode E35 (Fy). Similarly, the electrodes E45-1 (Fy) and E45-2 (Fy) are partial electrodes, respectively, and the aggregate of both functions as the electrode E45 (Fy).

By such a method, the component Fy is obtained by detecting the inclination of the first columnar body T1 in the Y-axis direction based on the difference between signals generated at the pair of electrodes E13 (Fy) and E14 (Fy). The inclination of the second columnar body T2 in the Y-axis direction is detected based on the difference between the signals generated at the pair of electrodes E23 (Fy) and E24 (Fy), and a component Fy ^{* including an} error is detected by the sum of these inclinations. The error (the other-axis interference of the component Mx) is obtained by using the electrode E35 (Fy) [actually, an assembly of the partial electrodes E35-1 (Fy) and E35-2 (Fy)] and the electrode E45 (Fy This is because they are canceled by the difference in signal generated between the partial electrodes E45-1 (Fy) and E45-2 (Fy).

  For the component Fz, i = 3 is set, and an arithmetic expression “Fz = Fz3” is selected, and an expression using an actual capacitance value is “Fz = − (C15 + C25 + C35 + C45)”. Therefore, as shown in the figure, if the electrodes E15 (Fz), E25 (Fz), E35 (Fz), and E45 (Fz) are wired to the terminal Tfz (−), the sign of the electric signal generated at the terminal Tfz (−) is reversed. By doing so, the component Fz can be obtained.

  For the component Mx, i = 3 is set, and an arithmetic expression “Mx = Mx3” is selected, and an expression using an actual capacitance value is “Mx = C45−C35”. Therefore, as shown in the drawing, if the electrodes E35-1 (Mx) and E35-2 (Mx) are wired to the terminal Tmx1, and the electrodes E45-1 (Mx) and E45-2 (Mx) are wired to the terminal Tmx2, both ends The component Mx can be obtained by the difference in the electrical signal generated in the child. Here, the electrodes E35-1 (Mx) and E35-2 (Mx) are partial electrodes, respectively, and the aggregate of both functions as the electrode E35 (Mx). Similarly, the electrodes E45-1 (Mx) and E45-2 (Mx) are partial electrodes, respectively, and the aggregate of both functions as the electrode E45 (Mx).

  For the component My, i = 3 is set, and an arithmetic expression “My = My3” is selected, and an expression using an actual capacitance value is “My = C15−C25”. Therefore, as shown in the drawing, if the electrodes E15-1 (My) and E15-2 (My) are wired to the terminal Tmy1, and the electrodes E25-1 (My) and E25-2 (My) are wired to the terminal Tmy2, both ends The component My can be obtained by the difference between the electrical signals generated in the child. Here, the electrodes E15-1 (My) and E15-2 (My) are partial electrodes, respectively, and the aggregate of both functions as the electrode E15 (My). Similarly, the electrodes E25-1 (My) and E25-2 (My) are partial electrodes, respectively, and the aggregate of both functions as the electrode E25 (My).

  For the component Mz, the calculation formula “Mz = Mz1” is selected by setting i = 1, and the formula using the actual capacitance value is “Mz = (C13 + C24 + C32 + C41) − (C14 + C23 + C31 + C42)”. Become. Therefore, as illustrated, the electrodes E13 (Mz), E24 (Mz), E32 (Mz), and E41 (Mz) are wired to the terminal Tmz1, and the electrodes E14 (Mz), E23 (Mz), E31 (Mz), and E42 are connected. If (Mz) is wired to the terminal Tmz2, the component Mz can be obtained by the difference between the electrical signals generated at both terminals.

1 is a perspective view (partially a block diagram) showing a basic configuration of a force detection device according to the present invention. It is a front view which shows the fundamental operation | movement principle of the force detection apparatus shown in FIG. It is a sectional side view (cross-sectional view cut by xz plane) which shows an example of the multi-axis force sensor suitable for using as the 1st sensor 21-the 4th sensor 24 in the force detection apparatus shown in FIG. FIG. 4 is a top view of the multi-axis force sensor shown in FIG. 3. It is a top view of the support substrate 40 in the multi-axis force sensor shown in FIG. 3 (the broken line indicates the position of the hook-shaped connecting member). FIG. 4 is a side sectional view showing a state when a force + fx in the x-axis positive direction is applied to the multi-axis force sensor shown in FIG. 3. FIG. 4 is a side sectional view showing a state when a force −fx in the negative x-axis direction is applied to the multi-axis force sensor shown in FIG. 3. FIG. 4 is a side sectional view showing a state when a force −fz in the negative z-axis direction is applied to the multi-axis force sensor shown in FIG. 3. 1 is a top view of a force detection device according to a basic embodiment of the present invention. FIG. 10 is a first side cross-sectional view of the force detection device according to the basic embodiment of the present invention, and shows a cross section of the device shown in FIG. 9 cut along the XZ plane. FIG. 10 is a second side cross-sectional view of the force detection device according to the basic embodiment of the present invention, and shows a cross section obtained by cutting the device shown in FIG. 9 along the YZ plane. FIG. 12 is a cross-sectional view showing a state where the force receiving body 100 of the force detection device shown in FIGS. 10 and 11 is cut along the X′Y ′ plane. FIG. 13 is a cross-sectional view illustrating a state in which the intermediate body 200 of the force detection device illustrated in FIGS. 10 and 11 is cut along a cutting line 13-13. 12 is a cross-sectional view illustrating a state in which the intermediate body 200 of the force detection device illustrated in FIGS. 10 and 11 is cut along an XY plane. FIG. FIG. 12 is a top view of a support substrate 300 of the force detection device shown in FIGS. 10 and 11. It is XZ side sectional drawing of the force detection apparatus which concerns on practical embodiment of this invention. FIG. 17 is a side sectional view showing a deformation mode of the structure when a force + Fx in the X-axis positive direction acts on the force detection device shown in FIG. 16. FIG. 17 is a side cross-sectional view showing a deformation mode of a structure when a force + Fz in the Z-axis positive direction acts on the force detection device shown in FIG. 16. FIG. 17 is a side sectional view showing a virtual deformation mode of a structure when a moment + My around the Y axis is applied to the force detection device shown in FIG. 16. FIG. 17 is a table showing the principle of detection of each force component by the force detection device shown in FIG. 16, and shows how the capacitance value of each capacitive element changes when each force component acts on the force receiving body (moment Assuming the hypothetical deformation mode shown in FIG. It is a figure which shows the principle which detects each force component based on the table shown in FIG. 20 using numerical formula. FIG. 17 is a side cross-sectional view showing an actual deformation mode of the structure when a moment + My around the Y-axis acts on the force detection device shown in FIG. 16. FIG. 17 is a table showing the principle of detection of each force component by the force detection device shown in FIG. 16, and shows how the capacitance value of each capacitive element changes when each force component acts on the force receiving body (moment Is assumed based on the actual deformation mode shown in FIG. It is a figure which shows the principle which detects each force component based on the table shown in FIG. 23 using numerical formula. It is a figure which shows the variation of the detection principle shown in FIG. 24 using numerical formula. In this invention, it is a figure which shows numerical formula which correct | amends other-axis interference. FIG. 27 is a side sectional view showing an example of an experimental method for determining coefficients αij and βij shown in FIG. 26. In this invention, it is a figure which shows the principle which cancels the other-axis interference with the force Fx of the X-axis direction by the moment My around the Y-axis. In this invention, it is a figure which shows the principle which cancels the other-axis interference with the force component Fy of the Y-axis direction by the moment Mx around an X-axis. It is a top view of the support substrate 300 which shows the wiring for detecting the force Fx of the X-axis direction with the force detection apparatus which concerns on fundamental embodiment of this invention. It is a top view of the support substrate 300 which shows the wiring for detecting the force Fy of a Y-axis direction with the force detection apparatus which concerns on fundamental embodiment of this invention. It is a top view of the support substrate 300 which shows the wiring for detecting the force Fz of a Z-axis direction with the force detection apparatus which concerns on fundamental embodiment of this invention. It is a top view of the support substrate 300 which shows the wiring for detecting the moment Mx around an X-axis with the force detection apparatus which concerns on fundamental embodiment of this invention. It is a top view of the support substrate 300 which shows the wiring for detecting the moment My around a Y-axis with the force detection apparatus which concerns on fundamental embodiment of this invention. It is a top view of the support substrate 300 which shows the wiring for detecting the moment Mz around a Z-axis with the force detection apparatus which concerns on fundamental embodiment of this invention. It is a top view which shows the basic example of the electrode arrangement | positioning for the sensor structure in the force detection apparatus which concerns on fundamental embodiment of this invention (The hatching is for showing the shape of each electrode clearly, and shows a cross section. Not a thing). It is a top view which shows the 1st modification of the electrode arrangement | positioning for the sensor structure in the force detection apparatus which concerns on fundamental embodiment of this invention (hatching is for showing the shape of each electrode clearly, It does not show a cross section). It is a top view which shows the 2nd modification of the electrode arrangement for the sensor structure in the force detection apparatus which concerns on basic embodiment of this invention (hatching is for showing the shape of each electrode clearly, It does not show a cross section). It is a top view which shows the 3rd modification of the electrode arrangement for the sensor structure in the force detection apparatus which concerns on basic embodiment of this invention (hatching is for showing the shape of each electrode clearly, It does not show a cross section). FIG. 6 is a top view of a support substrate 300 showing an electrode configuration of a practical embodiment of the present invention having a function of detecting all six force components (hatching is for clearly showing the shape of each electrode). Yes, not a cross section). It is a figure which shows the wiring method about each electrode shown by FIG. FIG. 41 is a top view of a support substrate 300 showing a modification example of FIG. 40 (hatching is for clearly showing the shape of each electrode, not for a cross section). It is a figure which shows the wiring method about each electrode shown by FIG.

Explanation of symbols

10: Power receiving body 11: First columnar body 12: Second columnar body 13: Third columnar body 14: Fourth columnar body 20: Support substrate 21: First sensor 22: Second sensor 23 : Third sensor 24: fourth sensor 30: detection circuit 40: support substrate 50: bowl-shaped connection member 51: thin part (common displacement electrode)
52: Side wall part 53: Fixed part 60: Columnar body 100: Power receiving body 110: Columnar projection part 115: Upper end side thin part 120: Columnar projection part 125: Upper end side thin part 130: Columnar projection part 135: Upper end side thin part 140: Columnar projection 145: Upper end thin portion 200: Intermediate 210: Columnar projection 215: Lower end thin portion 220: Columnar projection 225: Lower end thin portion 230: Columnar projection 235: Lower end thin portion 240: Cylindrical protrusion 245: Lower end thin portion 250: Control wall 260: Control wall 300: Support substrate 400: Measuring jig 410: Connection portion 420: Upper lid portion 430: Side wall portion 440: Flange portions C11 to C45: Capacitance element / Capacitance values d1 to d3 of the capacitive elements: gap sizes E1 to E5, E1a to E5b: fixed electrodes E11 to E15: individual fixed electrodes E21 to E25 for the first sensor: second sensor Individual fixed electrode E31～E35: third individual fixed electrode sensor E41～E45: fourth individual fixed electrode sensor Fx: X-axis direction force fx,: force in the x-axis direction Fx ^* , Fx1 ^{* to} Fx3 ^* , Fxi ^* : intermediate stage value for calculating Fx Fy: force Yy direction Fy ^* , Fy1 ^{* to} Fy3 ^* , Fyi ^* : intermediate stage value Fz for calculating Fy, Fz1 to Fz3 : Force in the Z-axis direction fz: Tensile force / pressing force acting on the support substrate G11 to G34: Grooves Mx, Mx1 to Mx3, Mxj: Moments My, My1 to My3, Myj around the X axis Moments Mz, Mz1 to Mz3: Moment around Z axis: Origin of coordinate system O ′: Origin of auxiliary coordinate system P1 to P3: Action points r1, r2: Length from origin to action point S1 to S4: Multi-axis Force T1-T4: Columnar bodies Tfx1, Tfx2: Force Fx detection terminals Tfy1, Tfy2: Force Fy detection terminals Tfz: Force Fz detection terminals Tmx1, Tmx2: Moment Mx detection terminals Tmy1, Tmy2: Moment My detection terminals Tmz1, Tmz2: Moment Mz detection terminals XYZ: Three-dimensional coordinate system X'Y'Z 'for defining a force to be detected: Auxiliary coordinates having an origin at the center position of the force receiving body System xyz: Local coordinate system αi, αj defined on the upper surface of the support substrate: Calculation values α, αij: Correction coefficients βi, βj: Calculation values β, βij: Correction coefficients θ1, θ2: Inclination angles of the columnar bodies 11, 12

Claims (21)

A support substrate, a force receiving body disposed above the support substrate, a first columnar body for connecting the support substrate and the force receiving body, and connecting the support substrate and the force receiving body. And a second columnar body for detecting the force acting on the power receiving body in a state where the support substrate is fixed,
An upper end of the first columnar body is connected to the power receiving body via a flexible member, and a lower end of the first columnar body is supported by the flexible member. Connected to the board,
The upper end of the second columnar body is connected to the force receiving body via a flexible member, and the lower end of the second columnar body is supported by the flexible member. Connected to the board,
An XY plane is positioned so as to be parallel to the upper surface of the support substrate at or above the upper surface of the support substrate, and the Z axis with the upper side being positive and the lower side being negative is substantially the center of the upper surface of the support substrate When defining the XYZ three-dimensional coordinate system to pass through the position,
The first columnar body is disposed at a position where the central axis is parallel to the Z axis and the central axis intersects the positive part of the X axis,
The second columnar body is arranged at a position where the central axis is parallel to the Z axis and the central axis intersects the negative part of the X axis,
A detector that is disposed near the lower end of the first columnar body and detects the inclination of the first columnar body in the X-axis direction, and Z that is applied to the support substrate from the entire first columnar body A first sensor having a detector for detecting a force in the axial direction;
A detector that is disposed near the lower end of the second columnar body and detects the inclination of the second columnar body in the X-axis direction, and Z that is applied to the support substrate from the entire second columnar body A second sensor having a detector for detecting a force in the axial direction;
A detection circuit that performs processing for obtaining an X-axis direction component Fx of the force acting on the force receiving body and outputting the obtained force based on the detection result of the first sensor and the detection result of the second sensor;
Further comprising
The detection circuit includes:
A calculation function for obtaining a sum Fx ^* of the inclination of the first columnar body in the X-axis direction and the inclination of the second columnar body in the X-axis direction
A calculation function for obtaining a difference My between the force in the Z-axis direction applied by the first columnar body and the force in the Z-axis direction applied by the second columnar body;
An arithmetic function for obtaining an X-axis direction component Fx of the force acting on the force receiving body based on an arithmetic expression “Fx = Fx ^* −α · My” using a predetermined coefficient α;
Have
The coefficient α is an expression “α = Fx ^* () using the value Fx ^* (0) of the sum Fx ^* and the value My (0) of the difference My obtained in an environment where only the moment about the Y-axis acts. 0) / My (0) ”is set to a value given by the force detection device. The force detection device according to claim 1,
A force detection device, wherein the detection circuit performs a process of outputting the obtained difference My as a moment component around the Y axis of the force acting on the force receiving body. The force detection device according to claim 1 or 2,
The detection circuit further has a calculation function for obtaining a sum Fz of the force in the Z-axis direction applied by the first columnar body and the force in the Z-axis direction applied by the second columnar body, and the obtained sum Fz Is output as a Z-axis direction component of the force acting on the force receiving body. In the force detection apparatus in any one of Claims 1-3,
Detection in which the first sensor further includes a detector that detects the inclination of the first columnar body in the Y-axis direction, and the second sensor detects the inclination of the second columnar body in the Y-axis direction. Have a child,
The detection circuit further has a calculation function for obtaining a difference Mz between the inclination of the first columnar body in the Y-axis direction and the inclination of the second columnar body in the Y-axis direction. A force detection device that performs a process of outputting a force acting on a body as a moment component around a Z-axis. In the force detection device according to any one of claims 1 to 4,
The upper end side thin portion having flexibility is connected to the upper end of each columnar body, the upper end side thin portion is connected to the power receiving body at the periphery, and the lower surface center portion is the columnar body. Connected to the top edge,
A flexible lower end side thin portion is connected to the lower end of each columnar body, and the lower end side thin portion is located at an upper position at a predetermined distance from the upper surface of the support substrate. The force detection device is characterized in that the periphery thereof is connected to the support substrate via a pedestal and the center portion of the upper surface thereof is connected to the lower end of the columnar body so as to be arranged in parallel with each other. The force detection device according to claim 5,
For each columnar body, an xy two-dimensional local coordinate having an origin at the intersection of the central axis of the columnar body and the upper surface of the support substrate, an x-axis parallel to the X-axis, and a y-axis parallel to the Y-axis When defining a system,
As a detector for detecting the inclination of the columnar body in the X-axis direction,
A first electrode formed in a region where the x-coordinate value is positive on the upper surface of the support substrate, and a first counter electrode formed at a position facing the first electrode on the lower surface of the lower end side thin portion A first capacitive element configured by:
A second electrode formed in a region where the x-coordinate value is negative on the upper surface of the support substrate, and a second counter electrode formed at a position facing the second electrode on the lower surface of the lower end side thin portion A second capacitive element configured by:
And a detector for obtaining a difference between the capacitance value C1 of the first capacitive element and the capacitance value C2 of the second capacitive element as an inclination in the X-axis direction of the columnar body,
When a detector that detects the inclination of the columnar body in the Y-axis direction is necessary,
A third electrode formed in a region where the y coordinate value is positive on the upper surface of the support substrate, and a third counter electrode formed at a position facing the third electrode on the lower surface of the lower end side thin portion. A third capacitive element configured by:
A fourth electrode formed in a region where the y-coordinate value is negative on the upper surface of the support substrate, and a fourth counter electrode formed at a position facing the fourth electrode on the lower surface of the lower end side thin portion. A fourth capacitive element configured by:
And a detector that obtains a difference between the capacitance value C3 of the third capacitive element and the capacitance value C4 of the fourth capacitive element as an inclination in the Y-axis direction of the columnar body is used.
As a detector for detecting the force in the Z-axis direction applied to the support substrate from the entire columnar body,
A fifth capacitor formed by a fifth electrode formed on the upper surface of the support substrate and a fifth counter electrode formed at a position facing the fifth electrode on the lower surface of the lower end side thin portion. A detector having an element, and obtaining a capacitance value C5 of the fifth capacitive element as a force in the Z-axis direction applied to the support substrate from the entire columnar body,
Each of the first electrode itself and the second electrode itself has a shape that is line-symmetric with respect to the x-axis, and the electrode group that includes the first electrode and the second electrode has a y-axis Has a line-symmetric shape with respect to
Each of the third electrode and the fourth electrode itself has a shape that is line-symmetric with respect to the y-axis, and the electrode group that includes the third electrode and the fourth electrode has an x-axis Has a line-symmetric shape with respect to
The force detection device according to claim 5, wherein the fifth electrode itself has a shape that is line-symmetric with respect to both the x-axis and the y-axis. A support substrate, a force receiving body disposed above the support substrate, a first columnar body for connecting the support substrate and the force receiving body, and connecting the support substrate and the force receiving body. A second columnar body for connecting, a third columnar body for connecting the support substrate and the power receiving body, and a fourth columnar body for connecting the support substrate and the power receiving body And a force detection device that detects a force acting on the force receiving body in a state where the support substrate is fixed,
An upper end of the first columnar body is connected to the power receiving body via a flexible member, and a lower end of the first columnar body is supported by the flexible member. Connected to the board,
The upper end of the second columnar body is connected to the force receiving body via a flexible member, and the lower end of the second columnar body is supported by the flexible member. Connected to the board,
An upper end of the third columnar body is connected to the power receiving body via a flexible member, and a lower end of the third columnar body is supported by the flexible member. Connected to the board,
The upper end of the fourth columnar body is connected to the power receiving body via a flexible member, and the lower end of the fourth columnar body is supported by the flexible member. Connected to the board,
An XY plane is positioned so as to be parallel to the upper surface of the support substrate at or above the upper surface of the support substrate, and the Z axis with the upper side being positive and the lower side being negative is substantially the center of the upper surface of the support substrate When defining the XYZ three-dimensional coordinate system to pass through the position,
The first columnar body is disposed at a position where the central axis is parallel to the Z axis and the central axis intersects the positive part of the X axis,
The second columnar body is arranged at a position where the central axis is parallel to the Z axis and the central axis intersects the negative part of the X axis,
The third columnar body is arranged at a position where the central axis is parallel to the Z axis and the central axis intersects the positive part of the Y axis,
The fourth columnar body is arranged at a position where the central axis is parallel to the Z axis and the central axis intersects the negative part of the Y axis,
A detector that is arranged near the lower end of the first columnar body and detects the inclination of the first columnar body in the X-axis direction, and a detection that detects the inclination of the first columnar body in the Y-axis direction. A first sensor comprising: a detector; and a detector for detecting a force in the Z-axis direction applied to the support substrate from the entire first columnar body;
A detector that is arranged near the lower end of the second columnar body and detects the inclination of the second columnar body in the X-axis direction, and a detection that detects the inclination of the second columnar body in the Y-axis direction. A second sensor comprising: a detector; and a detector for detecting a force in the Z-axis direction applied to the support substrate from the entire second columnar body;
A detector that is disposed near the lower end of the third columnar body and detects the inclination of the third columnar body in the X-axis direction, and a detection that detects the inclination of the third columnar body in the Y-axis direction. A third sensor comprising: a detector; and a detector for detecting a force in the Z-axis direction applied to the support substrate from the entire third columnar body;
A detector that is arranged near the lower end of the fourth columnar body and detects the inclination of the fourth columnar body in the X-axis direction, and a detection that detects the inclination of the fourth columnar body in the Y-axis direction. A fourth sensor comprising: a detector; and a detector for detecting a force in the Z-axis direction applied to the support substrate from the entire fourth columnar body;
Based on the detection result of the first sensor, the detection result of the second sensor, the detection result of the third sensor, and the detection result of the fourth sensor, the force acting on the force receiving body A detection circuit that performs processing for obtaining an X-axis direction component Fx and a Y-axis direction component Fy and outputting them;
Further comprising
The detection circuit includes:
“The inclination of the first columnar body in the X-axis direction, the inclination of the second columnar body in the X-axis direction, the inclination of the third columnar body in the X-axis direction, and the fourth columnar body "Fx1 ^* " with the inclination with respect to the X-axis direction or "Fx2 ^* with the inclination with respect to the X-axis direction of the first columnar body and the inclination with respect to the X-axis direction of the second columnar body" An arithmetic function for obtaining any one of the sums Fx3 ^* of the inclination of the third columnar body in the X-axis direction and the inclination of the fourth columnar body in the X-axis direction as a sum Fx ^* ;
“The inclination of the first columnar body in the Y-axis direction, the inclination of the second columnar body in the Y-axis direction, the inclination of the third columnar body in the Y-axis direction, and the fourth columnar body sum Fy2 ^* "or" said sum Fy1 ^* "or" inclination in the Y-axis directions of inclination and the second columnar body in the Y-axis direction of the first columnar body of the inclination about the Y-axis direction An arithmetic function for obtaining any one of the sums Fy3 ^* of the inclination of the third columnar body in the Y-axis direction and the inclination of the fourth columnar body in the Y-axis direction as a sum Fy ^* ;
A calculation function for obtaining a difference My between the force in the Z-axis direction applied by the first columnar body and the force in the Z-axis direction applied by the second columnar body;
A calculation function for obtaining a difference Mx between a force in the Z-axis direction applied by the third columnar body and a force in the Z-axis direction applied by the fourth columnar body;
An arithmetic function for obtaining an X-axis direction component Fx of the force acting on the force receiving body based on an arithmetic expression “Fx = Fx ^* −α · My” using a predetermined coefficient α;
An arithmetic function for obtaining a Y-axis direction component Fy of the force acting on the force receiving body based on an arithmetic expression “Fy = Fy ^* + β · Mx” using a predetermined coefficient β;
Have
The coefficient α is an expression “α = Fx ^* () using the value Fx ^* (0) of the sum Fx ^* and the value My (0) of the difference My obtained in an environment where only the moment about the Y-axis acts. 0) / My (0) ”,
The coefficient β is an expression “β = −Fy ^* ” using the value Fy ^* (0) of the sum Fy ^* and the value Mx (0) of the difference Mx obtained in an environment in which only the moment about the X axis acts ^. (0) / Mx (0) ”is set to a value given by the force detection device. The force detection device according to claim 7,
The detection circuit outputs the obtained difference My as a moment component around the Y axis of the force acting on the force receiving body, and outputs the obtained difference Mx as a moment component around the X axis of the force acting on the force receiving body. A force detection apparatus characterized by performing processing to perform. The force detection device according to claim 7 or 8,
The detection circuit includes a force in the Z-axis direction applied by the first columnar body, a force in the Z-axis direction applied by the second columnar body, a force in the Z-axis direction applied by the third columnar body, and the first 4 further includes a calculation function for obtaining a sum Fz with the force in the Z-axis direction applied by the four columnar bodies, and outputting the obtained sum Fz as a Z-axis direction component Fz of the force acting on the force receiving body. A force detection device characterized by performing. In the force detection device according to any one of claims 7 to 9,
The detection circuit detects that the sum of the slope of the first columnar body in the Y-axis direction and the slope of the fourth columnar body in the X-axis direction, the slope of the second columnar body in the Y-axis direction, and the third The difference Mz1 between the sum of the inclination of the columnar body in the X-axis direction and the difference Mz2 between the inclination of the first columnar body in the Y-axis direction and the inclination of the second columnar body in the Y-axis direction. Or “the difference Mz3 between the inclination of the fourth columnar body in the X-axis direction and the inclination of the third columnar body in the X-axis direction” as the difference Mz. A force detection device that performs a process of outputting the difference Mz as a moment component around the Z-axis of a force acting on a force receiving body. In the force detection apparatus in any one of Claims 7-10,
The upper end side thin portion having flexibility is connected to the upper end of each columnar body, the upper end side thin portion is connected to the power receiving body at the periphery, and the lower surface center portion is the columnar body. Connected to the top edge,
A flexible lower end side thin portion is connected to the lower end of each columnar body, and the lower end side thin portion is located at an upper position at a predetermined distance from the upper surface of the support substrate. The force detection device is characterized in that the periphery thereof is connected to the support substrate via a pedestal and the center portion of the upper surface thereof is connected to the lower end of the columnar body so as to be arranged in parallel with each other. The force detection device according to claim 11.
For each columnar body, an xy two-dimensional local coordinate having an origin at the intersection of the central axis of the columnar body and the upper surface of the support substrate, an x-axis parallel to the X-axis, and a y-axis parallel to the Y-axis When defining a system,
As a detector for detecting the inclination of the columnar body in the X-axis direction,
A first electrode formed in a region where the x-coordinate value is positive on the upper surface of the support substrate, and a first counter electrode formed at a position facing the first electrode on the lower surface of the lower end side thin portion A first capacitive element configured by:
A second electrode formed in a region where the x-coordinate value is negative on the upper surface of the support substrate, and a second counter electrode formed at a position facing the second electrode on the lower surface of the lower end side thin portion A second capacitive element configured by:
And a detector for obtaining a difference between the capacitance value C1 of the first capacitive element and the capacitance value C2 of the second capacitive element as an inclination in the X-axis direction of the columnar body,
As a detector for detecting the inclination of the columnar body in the Y-axis direction,
A third electrode formed in a region where the y coordinate value is positive on the upper surface of the support substrate, and a third counter electrode formed at a position facing the third electrode on the lower surface of the lower end side thin portion. A third capacitive element configured by:
A fourth electrode formed in a region where the y-coordinate value is negative on the upper surface of the support substrate, and a fourth counter electrode formed at a position facing the fourth electrode on the lower surface of the lower end side thin portion. A fourth capacitive element configured by:
And a detector that obtains a difference between the capacitance value C3 of the third capacitive element and the capacitance value C4 of the fourth capacitive element as an inclination in the Y-axis direction of the columnar body is used.
As a detector for detecting the force in the Z-axis direction applied to the support substrate from the entire columnar body,
A fifth capacitor formed by a fifth electrode formed on the upper surface of the support substrate and a fifth counter electrode formed at a position facing the fifth electrode on the lower surface of the lower end side thin portion. A detector having an element, and obtaining a capacitance value C5 of the fifth capacitive element as a force in the Z-axis direction applied to the support substrate from the entire columnar body,
Each of the first electrode itself and the second electrode itself has a shape that is line-symmetric with respect to the x-axis, and the electrode group that includes the first electrode and the second electrode has a y-axis Has a line-symmetric shape with respect to
Each of the third electrode and the fourth electrode itself has a shape that is line-symmetric with respect to the y-axis, and the electrode group that includes the third electrode and the fourth electrode has an x-axis Has a line-symmetric shape with respect to
The force detection device according to claim 5, wherein the fifth electrode itself has a shape that is line-symmetric with respect to both the x-axis and the y-axis. A support substrate, a force receiving body disposed above the support substrate, and four columnar bodies for connecting the support substrate and the force receiving body, in a state where the support substrate is fixed A force detection device for detecting a force acting on the force receiving body,
The upper ends of the four columnar bodies are respectively connected to flexible thin portions on the upper end side, and the lower ends of the four columnar bodies are respectively connected to the lower end sides having flexibility. The thin part is connected,
The upper end side thin part is connected to the power receiving body at the periphery thereof, and the center part of the lower surface is connected to the upper end of the columnar body,
The lower end side thin portion is connected to the support substrate via a pedestal so that the lower end side thin portion is disposed parallel to the upper surface of the support substrate at an upper position with a predetermined distance from the upper surface of the support substrate. The center of the upper surface is connected to the lower end of the columnar body,
An XY plane is positioned so as to be parallel to the upper surface of the support substrate at or above the upper surface of the support substrate, and the Z axis with the upper side being positive and the lower side being negative is substantially the center of the upper surface of the support substrate When defining the XYZ three-dimensional coordinate system to pass through the position,
The four columnar bodies are arranged so that their central axes are parallel to the Z axis, and the first columnar body is arranged at a position where the central axis intersects the positive part of the X axis. The second columnar body is disposed at a position where the central axis intersects the negative portion of the X axis, and the third columnar body is disposed at a position where the central axis intersects the positive portion of the Y axis. And the fourth columnar body is arranged at a position where the central axis intersects the negative part of the Y-axis,
One electrode is formed on the lower surface of the lower end side thin portion in a space sandwiched between the lower end side thin portion of the first columnar body and the upper surface of the support substrate facing the first columnar body, and the other electrode is the support A first sensor comprising a plurality of capacitive elements formed on the upper surface of the substrate is configured,
One electrode is formed on the lower surface of the lower end thin portion in a space sandwiched between the lower end thin portion of the second columnar body and the upper surface of the support substrate opposed thereto, and the other electrode is the support A second sensor comprising a plurality of capacitive elements formed on the upper surface of the substrate;
One electrode is formed on the lower surface of the lower-side thin portion in a space sandwiched between the lower-side thin portion of the third columnar body and the upper surface of the support substrate facing the third columnar body, and the other electrode is the support A third sensor composed of a plurality of capacitive elements formed on the upper surface of the substrate is configured,
One electrode is formed on the lower surface of the lower-side thin portion in a space sandwiched between the lower-side thin portion of the fourth columnar body and the upper surface of the support substrate facing the fourth columnar body, and the other electrode is the support A fourth sensor comprising a plurality of capacitive elements formed on the upper surface of the substrate is configured,
As a capacitor element candidate constituting the first sensor,
When the first columnar body is inclined in the X-axis positive direction, the capacitance value is increased by narrowing the electrode interval, and when the first columnar body is inclined in the X-axis negative direction, the electrode interval is increased. When the capacitance value decreases and the first columnar body is inclined in the positive direction of the Y axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the first columnar body is not changed. When the columnar body is inclined in the negative Y-axis direction, a capacitance element C11 is formed so that a part of the electrode interval is narrowed while another part is widened so that the capacitance value does not change.
When the first columnar body inclines in the X-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the first columnar body inclines in the X-axis negative direction, the electrode interval decreases. When the capacitance value increases and the first columnar body is tilted in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change and the first columnar body is not changed. When the columnar body is tilted in the negative Y-axis direction, a capacitance element C12 is formed so that a part of the electrode interval is narrowed but another part is widened so that the capacitance value does not change.
When the first columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the first columnar body is in the X-axis negative direction. When tilted, a part of the electrode interval narrows, but another part widens, so that the capacitance value does not change. When the first columnar body tilts in the positive Y-axis direction, the electrode interval narrows, resulting in a capacitance. A capacitance element C13 formed so that the capacitance value decreases when the value increases and when the first columnar body is inclined in the negative Y-axis direction, the electrode interval is widened;
When the first columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the first columnar body is in the X-axis negative direction. When tilted, a part of the electrode spacing is narrowed, but another part is widened so that the capacitance value does not change. When the first columnar body is tilted in the positive direction of the Y axis, the spacing between the electrodes is widened to increase the capacitance. A capacitance element C14 formed such that the capacitance value increases when the value decreases and when the first columnar body is inclined in the negative Y-axis direction, the electrode interval is narrowed;
When the first columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the first columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed. When the capacitance value increases and the first columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is reduced, but another part is A capacitive element C15 formed so that the capacitance value does not change by spreading,
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the second sensor,
When the second columnar body is inclined in the X-axis positive direction, the capacitance value is increased by narrowing the electrode interval, and when the second columnar body is inclined in the X-axis negative direction, the electrode interval is increased. When the capacitance value decreases and the second columnar body is inclined in the Y-axis positive direction, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change and the second columnar body is not changed. When the columnar body is tilted in the negative Y-axis direction, a capacitance element C21 is formed so that a part of the electrode interval is narrowed but another part is widened so that the capacitance value does not change.
When the second columnar body is inclined in the positive X-axis direction, the capacitance value is reduced by widening the electrode interval, and when the second columnar body is inclined in the negative X-axis direction, the electrode interval is reduced. When the capacitance value increases and the second columnar body is inclined in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change and the second value is not changed. When the columnar body is inclined in the negative Y-axis direction, a capacitive element C22 formed so that a part of the electrode interval is narrowed but another part is widened so that the capacitance value does not change;
When the second columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the second columnar body is in the X-axis negative direction. When tilted, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change. When the second columnar body is tilted in the positive direction of the Y axis, the electrode interval is narrowed, thereby causing a capacitance. A capacitance element C23 formed so that the capacitance value decreases when the value increases and the second columnar body inclines in the negative direction of the Y-axis to increase the electrode interval;
When the second columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the second columnar body is in the X-axis negative direction. When tilted, a part of the electrode interval narrows, but another part widens, so that the capacitance value does not change. When the second columnar body tilts in the positive direction of the Y-axis, the electrode spacing increases, thereby increasing the capacitance. A capacitance element C24 formed such that the capacitance value increases when the value decreases and the second columnar body tilts in the negative Y-axis direction, and the electrode interval is narrowed;
When the second columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the second columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed. When the capacitance value increases and the second columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is narrowed, but another part is A capacitance element C25 formed so that the capacitance value does not change by spreading,
5 types of capacitive elements are defined,
As a capacitive element candidate constituting the third sensor,
When the third columnar body is inclined in the X-axis positive direction, the capacitance value is increased by narrowing the electrode interval, and when the third columnar body is inclined in the X-axis negative direction, the electrode interval is increased. When the capacitance value decreases and the third columnar body tilts in the positive Y-axis direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the third value is not changed. When the columnar body is inclined in the negative Y-axis direction, a capacitance element C31 is formed so that a part of the electrode interval is narrowed but another part is widened so that the capacitance value does not change.
When the third columnar body is inclined in the X-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the third columnar body is inclined in the X-axis negative direction, the electrode interval is decreased. When the capacitance value increases and the third columnar body is inclined in the positive direction of the Y axis, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change, and the third value is not changed. When the columnar body is tilted in the negative Y-axis direction, a capacitance element C32 is formed so that a part of the electrode interval is narrowed but another part is widened so that the capacitance value does not change.
When the third columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the third columnar body is in the X-axis negative direction. When tilted, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change. When the third columnar body is tilted in the positive direction of the Y axis, the electrode interval is narrowed, so that the capacitance A capacitance element C33 formed such that the capacitance value decreases when the value increases and the third columnar body inclines in the negative direction of the Y-axis to increase the electrode interval;
When the third columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the third columnar body is in the X-axis negative direction. When tilted, a part of the electrode interval narrows, but another part widens, so that the capacitance value does not change. When the third columnar body tilts in the positive direction of the Y-axis, the electrode spacing increases, thereby increasing the capacitance. A capacitance element C34 formed such that when the value decreases and the third columnar body inclines in the negative Y-axis direction, the capacitance value increases due to the electrode interval being narrowed;
When the third columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the third columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed. When the capacitance value increases and the third columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is reduced, but another part is A capacitive element C35 formed such that the capacitance value does not change by spreading,
5 types of capacitive elements are defined,
As a capacitive element candidate constituting the fourth sensor,
When the fourth columnar body is inclined in the X-axis positive direction, the capacitance value is increased by narrowing the electrode interval, and when the fourth columnar body is inclined in the X-axis negative direction, the electrode interval is increased. When the capacitance value decreases and the fourth columnar body is inclined in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change, and the fourth value When the columnar body is tilted in the negative Y-axis direction, a capacitive element C41 formed such that a part of the electrode interval is narrowed but another part is widened so that the capacitance value does not change;
When the fourth columnar body is inclined in the positive X-axis direction, the capacitance value is reduced by widening the electrode interval, and when the fourth columnar body is inclined in the negative X-axis direction, the electrode interval is reduced. When the capacitance value increases and the fourth columnar body is inclined in the Y-axis positive direction, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change, and the fourth value is not changed. When the columnar body is tilted in the negative Y-axis direction, a capacitance element C42 formed so that the capacitance value does not change by narrowing part of the electrode interval but widening another portion,
When the fourth columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the fourth columnar body is in the X-axis negative direction. When tilted, a part of the electrode spacing narrows, but another part widens, so that the capacitance value does not change. When the fourth columnar body tilts in the positive direction of the Y axis, the spacing between the electrodes narrows, resulting in a capacitance. A capacitance element C43 formed so that the capacitance value decreases when the value increases and the fourth columnar body is inclined in the negative direction of the Y-axis, and the electrode interval is widened;
When the fourth columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the fourth columnar body is in the X-axis negative direction. When tilted, a part of the electrode interval narrows, but another part widens, so that the capacitance value does not change, and when the fourth columnar body tilts in the positive direction of the Y axis, the electrode spacing increases, thereby increasing the capacitance. A capacitance element C44 formed such that when the value decreases and the fourth columnar body inclines in the negative Y-axis direction, the capacitance value increases due to the electrode interval being narrowed;
When the fourth columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the fourth columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed. When the capacitance value increases and the fourth columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is narrowed, but another part is A capacitive element C45 formed so that the capacitance value does not change by spreading,
5 types of capacitive elements are defined,
The X-axis direction component of the force acting on the force receiving member is Fx, the Y-axis direction component is Fy, the Z-axis direction component is Fz, the moment component around the X-axis is Mx, the moment component around the Y-axis is My, Z-axis The moment component around is Mz, the intermediate values used in the process of obtaining Fx and Fy are Fx ^* and Fy ^* , respectively, and the capacitance values of the capacitive elements are indicated by the same symbols as the symbols of the capacitive elements, respectively. I mean,
As a formula for calculating Fx ^* ,
Fx1 ^* = (C11-C12) + (C21-C22) + (C31-C32) + (C41-C42)
Fx2 ^* = (C11-C12) + (C21-C22)
Fx3 ^* = (C31-C32) + (C41-C42)
Define the following three formulas,
As a formula for obtaining Fy ^* ,
Fy1 ^* = (C13-C14) + (C23-C24) + (C33-C34) + (C43-C44)
Fy2 ^* = (C13-C14) + (C23-C24)
Fy3 ^* = (C33-C34) + (C43-C44)
Define the following three formulas,
As an expression for calculating Fz,
Fz1 = − ((C11 + C12 + C13 + C14 + C15) + (C21 + C22 + C23 + C24 + C25) + (C31 + C32 + C33 + C34 + C35) + (C41 + C42 + C43 + C44 + C45))
Fz2 = − ((C11 + C12 + C13 + C14) + (C21 + C22 + C23 + C24) + (C31 + C32 + C33 + C34) + (C41 + C42 + C43 + C44))
Fz3 = − (C15 + C25 + C35 + C45)
Define the following three formulas,
As an expression for obtaining Mx,
Mx1 = (C41 + C42 + C43 + C44 + C45) − (C31 + C32 + C33 + C34 + C35)
Mx2 = (C41 + C42 + C43 + C44)-(C31 + C32 + C33 + C34)
Mx3 = (C45-C35)
Define the following three formulas,
As an expression for calculating My,
My1 = (C11 + C12 + C13 + C14 + C15) − (C21 + C22 + C23 + C24 + C25)
My2 = (C11 + C12 + C13 + C14) − (C21 + C22 + C23 + C24)
My3 = (C15-C25)
Define the following three formulas,
As an expression for obtaining Mz,
Mz1 = ((C13-C14) + (C41-C42))-((C23-C24) + (C31-C32))
Mz2 = (C13-C14)-(C23-C24)
Mz3 = (C41-C42)-(C31-C32)
When defining the following three formulas,
From the candidate capacitive elements,
Fx = Fxi ^* −αij · Myj (where i = 1 to 3, j = 1 to 3)
Fy = Fyi ^* + βij · Mxj (where i = 1 to 3, j = 1 to 3)
Fz = Fzi (where i = 1 to 3)
Mx = Mxi (where i = 1 to 3)
My = Myi (where i = 1 to 3)
Mz = Mzi (where i = 1 to 3)
Capacitance elements necessary for performing an operation based on an expression selected from the following six expressions (however, selection of the Fx expression and the Fy expression is essential) are actually formed, and Equipped with a detection circuit to perform,
The coefficient αij is an expression “αij = Fxi ^* (0) using the value Fxi ^* (0) of the Fxi ^{* and} the value Myj (0) of the Myj obtained in an environment where only the moment about the Y-axis acts. / Myj (0) ”is set to the value given by
As for the coefficient βij, an expression “βij = −Fyi ^* (0) using the value Fyi ^* (0) of the Fyi ^{* and} the value Mxj (0) of the Mxj obtained in an environment in which only a moment around the X axis acts. ) / Mxj (0) ”, the force detection device is characterized by being set. In the force detection device according to claim 13, instead of the capacitive element candidate according to claim 13,
For each columnar body, an xy two-dimensional local coordinate having an origin at the intersection of the central axis of the columnar body and the upper surface of the support substrate, an x-axis parallel to the X-axis, and a y-axis parallel to the Y-axis When defining a system,
As a candidate of the capacitive element constituting the first sensor,
On the upper surface of the support substrate, on the first columnar body x-axis positive side electrode formed in a region where the x coordinate value in the local coordinate system for the first columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitance element C11 including a counter electrode formed at a position facing the first x-axis positive electrode for the columnar body,
On the upper surface of the support substrate, on the first columnar body x-axis negative electrode formed in a region where the x coordinate value in the local coordinate system for the first columnar body is negative, and on the lower surface of the lower end side thin portion, A capacitive element C12 constituted by a counter electrode formed at a position facing the first columnar x-axis negative electrode,
On the upper surface of the support substrate, on the first columnar body y-axis positive side electrode formed in a region where the y coordinate value in the local coordinate system for the first columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C13 configured by a counter electrode formed at a position facing the first y-axis positive electrode for the columnar body;
On the upper surface of the support substrate, on the first columnar body y-axis negative electrode formed in a region where the y coordinate value in the local coordinate system for the first columnar body is negative, and on the lower surface of the lower end thin portion, A capacitive element C14 configured by a counter electrode formed at a position facing the first y-axis negative electrode for the columnar body;
On the upper surface of the support substrate, the first columnar body Z-axis displacement detection electrode formed at a predetermined position in the local coordinate system of the first columnar body, and the lower surface of the lower end side thin portion, the first columnar body A capacitive element C15 configured by a counter electrode formed at a position facing the body Z-axis displacement detection electrode;
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the second sensor,
On the upper surface of the support substrate, on the lower surface of the second columnar body x-axis positive side electrode formed in the region where the x coordinate value in the local coordinate system of the second columnar body is positive, and the lower end side thin portion, A capacitance element C21 configured by a counter electrode formed at a position facing the second columnar x-axis positive side electrode;
On the upper surface of the support substrate, on the second columnar body x-axis negative electrode formed in a region where the x coordinate value in the local coordinate system for the second columnar body is negative, and on the lower surface of the lower end side thin portion, A capacitance element C22 including a counter electrode formed at a position facing the second columnar x-axis negative electrode,
On the upper surface of the support substrate, on the second columnar y-axis positive side electrode formed in the region where the y coordinate value in the local coordinate system is positive, and on the lower surface of the lower end thin portion, A capacitance element C23 constituted by a counter electrode formed at a position facing the second columnar y-axis positive side electrode;
On the upper surface of the support substrate, on the second columnar body y-axis negative side electrode formed in a region where the y coordinate value in the local coordinate system for the second columnar body is negative, and on the lower surface of the lower end side thin portion, A capacitance element C24 constituted by a counter electrode formed at a position facing the second columnar y-axis negative electrode,
A second columnar body Z-axis displacement detection electrode formed at a predetermined position in the local coordinate system of the second columnar body on the upper surface of the support substrate, and a lower surface of the lower end side thin portion, the second columnar shape A capacitive element C25 constituted by a counter electrode formed at a position facing the body Z-axis displacement detection electrode;
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the third sensor,
On the upper surface of the support substrate, on the third columnar body x-axis positive side electrode formed in a region where the x coordinate value in the local coordinate system of the third columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C31 configured by a counter electrode formed at a position facing the third columnar x-axis positive electrode,
On the upper surface of the support substrate, on the third columnar body x-axis negative electrode formed in a region where the x coordinate value in the local coordinate system is negative, and on the lower surface of the lower end thin portion, A capacitive element C32 configured by a counter electrode formed at a position facing the third columnar x-axis negative electrode,
On the upper surface of the support substrate, on the third columnar body y-axis positive side electrode formed in a region where the y coordinate value in the local coordinate system is positive, and on the lower surface of the lower end side thin portion, A capacitive element C33 configured by a counter electrode formed at a position facing the third columnar y-axis positive electrode,
On the upper surface of the support substrate, on the third columnar body y-axis negative side electrode formed in the region where the y coordinate value in the local coordinate system is negative, and on the lower surface of the lower end thin portion, A capacitive element C34 constituted by a counter electrode formed at a position facing the third y-axis negative electrode for the columnar body;
The third columnar body Z-axis displacement detection electrode formed at a predetermined position in the local coordinate system of the third columnar body on the upper surface of the support substrate, and the lower surface of the lower end side thin portion, the third columnar shape A capacitive element C35 composed of a counter electrode formed at a position facing the body Z-axis displacement detection electrode;
5 types of capacitive elements are defined,
As a candidate of the capacitive element constituting the fourth sensor,
On the upper surface of the support substrate, on the fourth columnar x-axis positive electrode formed in the region where the x coordinate value in the local coordinate system is positive, and on the lower surface of the lower end thin portion, A capacitance element C41 configured by a counter electrode formed at a position facing the fourth columnar x-axis positive side electrode;
On the upper surface of the support substrate, on the fourth columnar x-axis negative electrode formed in the region where the x coordinate value in the local coordinate system is negative, and on the lower surface of the lower end side thin portion, A capacitive element C42 constituted by a counter electrode formed at a position facing the fourth columnar x-axis negative electrode,
On the upper surface of the support substrate, on the fourth y-axis positive side electrode for the columnar body formed in the region where the y coordinate value in the local coordinate system for the fourth columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C43 configured by a counter electrode formed at a position facing the fourth columnar y-axis positive side electrode;
On the upper surface of the support substrate, on the fourth columnar body y-axis negative side electrode formed in a region where the y coordinate value in the local coordinate system of the fourth columnar body is negative, and on the lower surface of the lower end thin portion, A capacitive element C44 constituted by a counter electrode formed at a position facing the fourth columnar y-axis negative electrode,
A fourth columnar body Z-axis displacement detection electrode formed at a predetermined position in the local coordinate system of the fourth columnar body on the upper surface of the support substrate, and a lower surface of the lower end side thin portion, the fourth columnar shape A capacitive element C45 constituted by a counter electrode formed at a position facing the body Z-axis displacement detection electrode;
5 types of capacitive elements are defined,
For each columnar electrode,
Each of the x-axis positive electrode itself and the x-axis negative electrode itself has a shape that is line symmetric with respect to the x-axis, and the electrode group that includes the x-axis positive electrode and the x-axis negative electrode is the y-axis. Has a line-symmetric shape with respect to
Each of the y-axis positive electrode itself and the y-axis negative electrode itself has a shape that is line-symmetric with respect to the y-axis, and the electrode group that includes the y-axis positive electrode and the y-axis negative electrode is an x-axis. Has a line-symmetric shape with respect to
A force detection device, wherein the Z-axis displacement detection electrode itself has a shape that is line-symmetric with respect to both the x-axis and the y-axis. The force detection device according to any one of claims 6, 12 to 14,
For a plurality of capacitive elements that are targets for calculating the sum of capacitance values, by performing wiring that is electrically connected to each other, the calculation for calculating the sum in the detection circuit is omitted,
A force detection device characterized in that the calculation of the product using the coefficient in the detection circuit is omitted by setting each capacitance element so that the coefficients α, β, αij, and βij are 1. A support substrate, a force receiving body disposed above the support substrate, and four columnar bodies for connecting the support substrate and the force receiving body, in a state where the support substrate is fixed A force detection device for detecting a force acting on the force receiving body,
The upper ends of the four columnar bodies are respectively connected to flexible thin portions on the upper end side, and the lower ends of the four columnar bodies are respectively connected to the lower end sides having flexibility. The thin part is connected,
The upper end side thin part is connected to the power receiving body at the periphery thereof, and the center part of the lower surface is connected to the upper end of the columnar body,
The lower end side thin portion is connected to the support substrate via a pedestal so that the lower end side thin portion is disposed parallel to the upper surface of the support substrate at an upper position with a predetermined distance from the upper surface of the support substrate. The center of the upper surface is connected to the lower end of the columnar body,
An XY plane is positioned so as to be parallel to the upper surface of the support substrate at or above the upper surface of the support substrate, and the Z axis with the upper side being positive and the lower side being negative is substantially the center of the upper surface of the support substrate When defining the XYZ three-dimensional coordinate system to pass through the position,
The four columnar bodies are arranged so that their central axes are parallel to the Z axis, and the first columnar body is arranged at a position where the central axis intersects the positive part of the X axis. The second columnar body is disposed at a position where the central axis intersects the negative portion of the X axis, and the third columnar body is disposed at a position where the central axis intersects the positive portion of the Y axis. And the fourth columnar body is arranged at a position where the central axis intersects the negative part of the Y-axis,
One electrode is formed on the lower surface of the lower end side thin portion in a space sandwiched between the lower end side thin portion of the first columnar body and the upper surface of the support substrate facing the first columnar body, and the other electrode is the support A first sensor comprising a plurality of capacitive elements formed on the upper surface of the substrate is configured,
One electrode is formed on the lower surface of the lower end thin portion in a space sandwiched between the lower end thin portion of the second columnar body and the upper surface of the support substrate opposed thereto, and the other electrode is the support A second sensor comprising a plurality of capacitive elements formed on the upper surface of the substrate;
One electrode is formed on the lower surface of the lower-side thin portion in a space sandwiched between the lower-side thin portion of the third columnar body and the upper surface of the support substrate facing the third columnar body, and the other electrode is the support A third sensor composed of a plurality of capacitive elements formed on the upper surface of the substrate is configured,
One electrode is formed on the lower surface of the lower-side thin portion in a space sandwiched between the lower-side thin portion of the fourth columnar body and the upper surface of the support substrate facing the fourth columnar body, and the other electrode is the support A fourth sensor comprising a plurality of capacitive elements formed on the upper surface of the substrate is configured,
As a capacitor element candidate constituting the first sensor,
When the first columnar body is inclined in the X-axis positive direction, the capacitance value is increased by narrowing the electrode interval, and when the first columnar body is inclined in the X-axis negative direction, the electrode interval is increased. When the capacitance value decreases and the first columnar body is inclined in the positive direction of the Y axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the first columnar body is not changed. When the columnar body is inclined in the negative Y-axis direction, a capacitance element C11 is formed so that a part of the electrode interval is narrowed while another part is widened so that the capacitance value does not change.
When the first columnar body inclines in the X-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the first columnar body inclines in the X-axis negative direction, the electrode interval decreases. When the capacitance value increases and the first columnar body is tilted in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change and the first columnar body is not changed. When the columnar body is tilted in the negative Y-axis direction, a capacitance element C12 is formed so that a part of the electrode interval is narrowed but another part is widened so that the capacitance value does not change.
When the first columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the first columnar body is in the X-axis negative direction. When tilted, a part of the electrode interval narrows, but another part widens, so that the capacitance value does not change. When the first columnar body tilts in the positive Y-axis direction, the electrode interval narrows, resulting in a capacitance. A capacitance element C13 formed so that the capacitance value decreases when the value increases and when the first columnar body is inclined in the negative Y-axis direction, the electrode interval is widened;
When the first columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the first columnar body is in the X-axis negative direction. When tilted, a part of the electrode spacing is narrowed, but another part is widened so that the capacitance value does not change. When the first columnar body is tilted in the positive direction of the Y axis, the spacing between the electrodes is widened to increase the capacitance. A capacitance element C14 formed such that the capacitance value increases when the value decreases and when the first columnar body is inclined in the negative Y-axis direction, the electrode interval is narrowed;
When the first columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the first columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed. When the capacitance value increases and the first columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is reduced, but another part is A capacitive element C15 formed so that the capacitance value does not change by spreading,
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the second sensor,
When the second columnar body is inclined in the X-axis positive direction, the capacitance value is increased by narrowing the electrode interval, and when the second columnar body is inclined in the X-axis negative direction, the electrode interval is increased. When the capacitance value decreases and the second columnar body is inclined in the Y-axis positive direction, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change and the second columnar body is not changed. When the columnar body is tilted in the negative Y-axis direction, a capacitance element C21 is formed so that a part of the electrode interval is narrowed but another part is widened so that the capacitance value does not change.
When the second columnar body is inclined in the positive X-axis direction, the capacitance value is reduced by widening the electrode interval, and when the second columnar body is inclined in the negative X-axis direction, the electrode interval is reduced. When the capacitance value increases and the second columnar body is inclined in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change and the second value is not changed. When the columnar body is inclined in the negative Y-axis direction, a capacitive element C22 formed so that a part of the electrode interval is narrowed but another part is widened so that the capacitance value does not change;
When the second columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the second columnar body is in the X-axis negative direction. When tilted, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change. When the second columnar body is tilted in the positive direction of the Y axis, the electrode interval is narrowed, thereby causing a capacitance. A capacitance element C23 formed so that the capacitance value decreases when the value increases and the second columnar body inclines in the negative direction of the Y-axis to increase the electrode interval;
When the second columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the second columnar body is in the X-axis negative direction. When tilted, a part of the electrode interval narrows, but another part widens, so that the capacitance value does not change. When the second columnar body tilts in the positive direction of the Y-axis, the electrode spacing increases, thereby increasing the capacitance. A capacitance element C24 formed such that the capacitance value increases when the value decreases and the second columnar body tilts in the negative Y-axis direction, and the electrode interval is narrowed;
When the second columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the second columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed. When the capacitance value increases and the second columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is narrowed, but another part is A capacitance element C25 formed so that the capacitance value does not change by spreading,
5 types of capacitive elements are defined,
As a capacitive element candidate constituting the third sensor,
When the third columnar body is inclined in the X-axis positive direction, the capacitance value is increased by narrowing the electrode interval, and when the third columnar body is inclined in the X-axis negative direction, the electrode interval is increased. When the capacitance value decreases and the third columnar body tilts in the positive Y-axis direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the third value is not changed. When the columnar body is inclined in the negative Y-axis direction, a capacitance element C31 is formed so that a part of the electrode interval is narrowed but another part is widened so that the capacitance value does not change.
When the third columnar body is inclined in the X-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the third columnar body is inclined in the X-axis negative direction, the electrode interval is decreased. When the capacitance value increases and the third columnar body is inclined in the positive direction of the Y axis, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change, and the third value is not changed. When the columnar body is tilted in the negative Y-axis direction, a capacitance element C32 is formed so that a part of the electrode interval is narrowed but another part is widened so that the capacitance value does not change.
When the third columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the third columnar body is in the X-axis negative direction. When tilted, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change. When the third columnar body is tilted in the positive direction of the Y axis, the electrode interval is narrowed, so that the capacitance A capacitance element C33 formed such that the capacitance value decreases when the value increases and the third columnar body inclines in the negative direction of the Y-axis to increase the electrode interval;
When the third columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is expanded, and the capacitance value does not change, and the third columnar body is in the X-axis negative direction. When tilted, a part of the electrode interval narrows, but another part widens, so that the capacitance value does not change. When the third columnar body tilts in the positive direction of the Y-axis, the electrode spacing increases, thereby increasing the capacitance. A capacitance element C34 formed such that when the value decreases and the third columnar body inclines in the negative Y-axis direction, the capacitance value increases due to the electrode interval being narrowed;
When the third columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the third columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed. When the capacitance value increases and the third columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is reduced, but another part is A capacitive element C35 formed such that the capacitance value does not change by spreading,
5 types of capacitive elements are defined,
As a capacitive element candidate constituting the fourth sensor,
When the fourth columnar body is inclined in the X-axis positive direction, the capacitance value is increased by narrowing the electrode interval, and when the fourth columnar body is inclined in the X-axis negative direction, the electrode interval is increased. When the capacitance value decreases and the fourth columnar body is inclined in the positive direction of the Y-axis, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change, and the fourth value When the columnar body is tilted in the negative Y-axis direction, a capacitive element C41 formed such that a part of the electrode interval is narrowed but another part is widened so that the capacitance value does not change;
When the fourth columnar body is inclined in the positive X-axis direction, the capacitance value is reduced by widening the electrode interval, and when the fourth columnar body is inclined in the negative X-axis direction, the electrode interval is reduced. When the capacitance value increases and the fourth columnar body is inclined in the Y-axis positive direction, a part of the electrode interval is narrowed, but another part is widened so that the capacitance value does not change, and the fourth value is not changed. When the columnar body is tilted in the negative Y-axis direction, a capacitance element C42 formed so that the capacitance value does not change by narrowing part of the electrode interval but widening another portion,
When the fourth columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the fourth columnar body is in the X-axis negative direction. When tilted, a part of the electrode spacing narrows, but another part widens, so that the capacitance value does not change. When the fourth columnar body tilts in the positive direction of the Y axis, the spacing between the electrodes narrows, resulting in a capacitance. A capacitance element C43 formed so that the capacitance value decreases when the value increases and the fourth columnar body is inclined in the negative direction of the Y-axis, and the electrode interval is widened;
When the fourth columnar body is inclined in the X-axis positive direction, a part of the electrode interval is narrowed, but another part is widened, so that the capacitance value does not change, and the fourth columnar body is in the X-axis negative direction. When tilted, a part of the electrode interval narrows, but another part widens, so that the capacitance value does not change, and when the fourth columnar body tilts in the positive direction of the Y axis, the electrode spacing increases, thereby increasing the capacitance. A capacitance element C44 formed such that when the value decreases and the fourth columnar body inclines in the negative Y-axis direction, the capacitance value increases due to the electrode interval being narrowed;
When the fourth columnar body is displaced in the Z-axis positive direction, the capacitance value is reduced by widening the electrode interval, and when the fourth columnar body is displaced in the Z-axis negative direction, the electrode interval is narrowed. When the capacitance value increases and the fourth columnar body tilts in the X-axis positive direction, the X-axis negative direction, the Y-axis positive direction, or the Y-axis negative direction, a part of the electrode interval is narrowed, but another part is A capacitive element C45 formed so that the capacitance value does not change by spreading,
5 types of capacitive elements are defined,
The X-axis direction component of the force acting on the force receiving member is Fx, the Y-axis direction component is Fy, the Z-axis direction component is Fz, the moment component around the X-axis is Mx, the moment component around the Y-axis is My, Z-axis The moment component around is Mz, the intermediate values used in the process of obtaining Fx and Fy are Fx ^* and Fy ^* , respectively, and the capacitance values of the capacitive elements are indicated by the same symbols as the symbols of the capacitive elements, respectively. I mean,
As a formula for calculating Fx ^* ,
Fx1 ^* = (C11-C12) + (C21-C22) + (C31-C32) + (C41-C42)
Fx2 ^* = (C11-C12) + (C21-C22)
Fx3 ^* = (C31-C32) + (C41-C42)
Define the following three formulas,
As a formula for obtaining Fy ^* ,
Fy1 ^* = (C13-C14) + (C23-C24) + (C33-C34) + (C43-C44)
Fy2 ^* = (C13-C14) + (C23-C24)
Fy3 ^* = (C33-C34) + (C43-C44)
Define the following three formulas,
As an expression for calculating Fz,
Fz1 = − ((C11 + C12 + C13 + C14 + C15) + (C21 + C22 + C23 + C24 + C25) + (C31 + C32 + C33 + C34 + C35) + (C41 + C42 + C43 + C44 + C45))
Fz2 = − ((C11 + C12 + C13 + C14) + (C21 + C22 + C23 + C24) + (C31 + C32 + C33 + C34) + (C41 + C42 + C43 + C44))
Fz3 = − (C15 + C25 + C35 + C45)
Define the following three formulas,
As an expression for obtaining Mx,
Mx1 = (C41 + C42 + C43 + C44 + C45) − (C31 + C32 + C33 + C34 + C35)
Mx2 = (C41 + C42 + C43 + C44)-(C31 + C32 + C33 + C34)
Mx3 = (C45-C35)
Define the following three formulas,
As an expression for calculating My,
My1 = (C11 + C12 + C13 + C14 + C15) − (C21 + C22 + C23 + C24 + C25)
My2 = (C11 + C12 + C13 + C14) − (C21 + C22 + C23 + C24)
My3 = (C15-C25)
Define the following three formulas,
As an expression for obtaining Mz,
Mz1 = ((C13-C14) + (C41-C42))-((C23-C24) + (C31-C32))
Mz2 = (C13-C14)-(C23-C24)
Mz3 = (C41-C42)-(C31-C32)
When defining the following three formulas,
From the candidate capacitive elements,
Fx = Fxi ^* −Myj (where i = 1 to 3, j = 1 to 3)
Fy = Fyi ^* + Mxj (where i = 1 to 3, j = 1 to 3)
Fz = Fzi (where i = 1 to 3)
Mx = Mxi (where i = 1 to 3)
My = Myi (where i = 1 to 3)
Mz = Mzi (where i = 1 to 3)
Capacitance elements necessary to perform an operation based on an expression selected from the following six expressions (however, selection of the Fx expression and the Fy expression is indispensable) are actually formed. When the capacitance value is used in a plurality of different expressions, a separate capacitive element is physically formed), and a detection circuit that performs the calculation is provided.
Among the capacitive elements that are actually formed, wiring that is electrically connected to each other for a plurality of capacitive elements that are targets of calculating the sum of capacitance values in the calculation based on the selected formula Is given,
For the Fxi ^* value Fxi ^* (0) and the Myj value Myj (0) obtained in an environment in which only the moment about the Y-axis acts, Fxi ^* (0) = Myj (0) holds. A capacitive element used for calculating the Fxi ^* and a capacitive element used for calculating the Myj are set.
-Fyi ^* (0) = Mxj (0) is satisfied with respect to the value Fyi ^* (0) of Fyi ^{* and} the value Mxj (0) of Mxj obtained in an environment in which only a moment around the X axis acts. A force detection device in which a capacitive element used for calculating Fyi ^* and a capacitive element used for calculating Mxj are set. In the force detection device according to claim 16, in place of the capacitive element candidate according to claim 16,
For each columnar body, an xy two-dimensional local coordinate having an origin at the intersection of the central axis of the columnar body and the upper surface of the support substrate, an x-axis parallel to the X-axis, and a y-axis parallel to the Y-axis When defining a system,
As a candidate of the capacitive element constituting the first sensor,
On the upper surface of the support substrate, on the first columnar body x-axis positive side electrode formed in a region where the x coordinate value in the local coordinate system for the first columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitance element C11 including a counter electrode formed at a position facing the first x-axis positive electrode for the columnar body,
On the upper surface of the support substrate, on the first columnar body x-axis negative electrode formed in a region where the x coordinate value in the local coordinate system for the first columnar body is negative, and on the lower surface of the lower end side thin portion, A capacitive element C12 constituted by a counter electrode formed at a position facing the first columnar x-axis negative electrode,
On the upper surface of the support substrate, on the first columnar body y-axis positive side electrode formed in a region where the y coordinate value in the local coordinate system for the first columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C13 configured by a counter electrode formed at a position facing the first y-axis positive electrode for the columnar body;
On the upper surface of the support substrate, on the first columnar body y-axis negative electrode formed in a region where the y coordinate value in the local coordinate system for the first columnar body is negative, and on the lower surface of the lower end thin portion, A capacitive element C14 configured by a counter electrode formed at a position facing the first y-axis negative electrode for the columnar body;
On the upper surface of the support substrate, the first columnar body Z-axis displacement detection electrode formed at a predetermined position in the local coordinate system of the first columnar body, and the lower surface of the lower end side thin portion, the first columnar body A capacitive element C15 configured by a counter electrode formed at a position facing the body Z-axis displacement detection electrode;
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the second sensor,
On the upper surface of the support substrate, on the lower surface of the second columnar body x-axis positive side electrode formed in the region where the x coordinate value in the local coordinate system of the second columnar body is positive, and the lower end side thin portion, A capacitance element C21 configured by a counter electrode formed at a position facing the second columnar x-axis positive side electrode;
On the upper surface of the support substrate, on the second columnar body x-axis negative electrode formed in a region where the x coordinate value in the local coordinate system for the second columnar body is negative, and on the lower surface of the lower end side thin portion, A capacitance element C22 including a counter electrode formed at a position facing the second columnar x-axis negative electrode,
On the upper surface of the support substrate, on the second columnar y-axis positive side electrode formed in the region where the y coordinate value in the local coordinate system is positive, and on the lower surface of the lower end thin portion, A capacitance element C23 constituted by a counter electrode formed at a position facing the second columnar y-axis positive side electrode;
On the upper surface of the support substrate, on the second columnar body y-axis negative side electrode formed in a region where the y coordinate value in the local coordinate system for the second columnar body is negative, and on the lower surface of the lower end side thin portion, A capacitance element C24 constituted by a counter electrode formed at a position facing the second columnar y-axis negative electrode,
A second columnar body Z-axis displacement detection electrode formed at a predetermined position in the local coordinate system of the second columnar body on the upper surface of the support substrate, and a lower surface of the lower end side thin portion, the second columnar shape A capacitive element C25 constituted by a counter electrode formed at a position facing the body Z-axis displacement detection electrode;
5 types of capacitive elements are defined,
As a candidate for the capacitive element constituting the third sensor,
On the upper surface of the support substrate, on the third columnar body x-axis positive side electrode formed in a region where the x coordinate value in the local coordinate system of the third columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C31 configured by a counter electrode formed at a position facing the third columnar x-axis positive electrode,
On the upper surface of the support substrate, on the third columnar body x-axis negative electrode formed in a region where the x coordinate value in the local coordinate system is negative, and on the lower surface of the lower end thin portion, A capacitive element C32 configured by a counter electrode formed at a position facing the third columnar x-axis negative electrode,
On the upper surface of the support substrate, on the third columnar body y-axis positive side electrode formed in a region where the y coordinate value in the local coordinate system is positive, and on the lower surface of the lower end side thin portion, A capacitive element C33 configured by a counter electrode formed at a position facing the third columnar y-axis positive electrode,
On the upper surface of the support substrate, on the third columnar body y-axis negative side electrode formed in the region where the y coordinate value in the local coordinate system is negative, and on the lower surface of the lower end thin portion, A capacitive element C34 constituted by a counter electrode formed at a position facing the third y-axis negative electrode for the columnar body;
The third columnar body Z-axis displacement detection electrode formed at a predetermined position in the local coordinate system of the third columnar body on the upper surface of the support substrate, and the lower surface of the lower end side thin portion, the third columnar shape A capacitive element C35 composed of a counter electrode formed at a position facing the body Z-axis displacement detection electrode;
5 types of capacitive elements are defined,
As a candidate of the capacitive element constituting the fourth sensor,
On the upper surface of the support substrate, on the fourth columnar x-axis positive electrode formed in the region where the x coordinate value in the local coordinate system is positive, and on the lower surface of the lower end thin portion, A capacitance element C41 configured by a counter electrode formed at a position facing the fourth columnar x-axis positive side electrode;
On the upper surface of the support substrate, on the fourth columnar x-axis negative electrode formed in the region where the x coordinate value in the local coordinate system is negative, and on the lower surface of the lower end side thin portion, A capacitive element C42 constituted by a counter electrode formed at a position facing the fourth columnar x-axis negative electrode,
On the upper surface of the support substrate, on the fourth y-axis positive side electrode for the columnar body formed in the region where the y coordinate value in the local coordinate system for the fourth columnar body is positive, and on the lower surface of the lower end side thin portion, A capacitive element C43 configured by a counter electrode formed at a position facing the fourth columnar y-axis positive side electrode;
On the upper surface of the support substrate, on the fourth columnar body y-axis negative side electrode formed in a region where the y coordinate value in the local coordinate system of the fourth columnar body is negative, and on the lower surface of the lower end thin portion, A capacitive element C44 constituted by a counter electrode formed at a position facing the fourth columnar y-axis negative electrode,
A fourth columnar body Z-axis displacement detection electrode formed at a predetermined position in the local coordinate system of the fourth columnar body on the upper surface of the support substrate, and a lower surface of the lower end side thin portion, the fourth columnar shape A capacitive element C45 constituted by a counter electrode formed at a position facing the body Z-axis displacement detection electrode;
5 types of capacitive elements are defined,
For each columnar electrode,
Each of the x-axis positive electrode itself and the x-axis negative electrode itself has a shape that is line symmetric with respect to the x-axis, and the electrode group that includes the x-axis positive electrode and the x-axis negative electrode is the y-axis. Has a line-symmetric shape with respect to
Each of the y-axis positive electrode itself and the y-axis negative electrode itself has a shape that is line-symmetric with respect to the y-axis, and the electrode group that includes the y-axis positive electrode and the y-axis negative electrode is an x-axis. Has a line-symmetric shape with respect to
A force detection device, wherein the Z-axis displacement detection electrode itself has a shape that is line-symmetric with respect to both the x-axis and the y-axis. The force detection device according to any one of claims 6, 12 to 17,
One of the electrodes constituting a specific one-capacitance element is constituted by an assembly of a plurality of partial electrodes arranged apart from each other. The force detection device according to any one of claims 6, 12 to 17,
An electrode formed on an upper surface side of a support substrate or an electrode formed on a lower end side thin portion side of a plurality of capacitive elements is physically constituted by a single common electrode. The force detection device according to claim 19,
Each of the lower end side thin portions is made of a conductive material, and the lower end side thin portion itself functions as a single common electrode. In the force detection device according to claim 1-20,
A force detection device characterized in that the shape and arrangement of each columnar body are plane-symmetric with respect to both the XZ plane and the YZ plane.