JP2018163047A - Tactile sense detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tactile sense detection device capable of precisely detecting a force even when the force from an object that should be detected changes in accordance with situations.SOLUTION: This tactile sense detection device 1 has a tactile sense detector 2, a tactile sense detection controller 6, and a measurement instrument 7. The tactile sense detector 2 includes: a base 3 formed with a supply path 32 communicated with an internal cavity 31 having an opening 31a internally communicated therewith and supplying a gas or liquid; a sheet part 4 for blocking the opening 31a of the internal cavity 31 and capable of inflating according to a pressure of the gas or the liquid of the internal cavity 31; and a sensor 5 for detecting an applied force and embedded in the sheet part 4 and capable of inclining by inflation of the sheet part 4. The tactile sense detection controller 6 supplies the gas or the liquid into the internal cavity 31 from the supply path 32, and the measurement instrument 7 measures a value detected by the sensor 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tactile sensing device.

  In remote operation of a gripping unit such as a robot, an operator is presented with a contact state between the gripping unit and an object held by the operator, and the operator must perform an appropriate remote control corresponding to the gripping unit. Therefore, the grasping unit is provided with a tactile detection device that detects a contact state with an object.

  For example, Patent Document 1 discloses a tactile sensing device in which a plurality of sensors (for example, pressure sensors) are arranged on the surface of a gripping portion of a robot having a flexible structure. In this tactile sensing device, the normal contact force acting on the surface of the gripping part at the start of gripping the object and the initial pressure gravity center position are measured, and then the flexible structure is subjected to external force (gravity) acting on the object when lifting the object. Since the pressure centroid position is deformed accordingly, the occurrence of slip can be determined and predicted based on the movement amount of the centroid position at that time.

  In Patent Document 2, air bags made of an elastic material are arranged in a gripping part of a robot or the like, and the internal pressure of the air bag is detected by a pressure sensor to sense the size and position of an object, and supply gas Thus, there is disclosed a tactile sensor that can change the internal pressure of the air bag to change the flexibility, thereby preventing slipping off.

JP 2006-297542 A JP 2008-149443 A

  By the way, the force from an object that must be detected by the tactile sensing device is less likely to change depending on the situation, for example, the stress of the object when gripping, and the force that the object tries to slip when maintaining gripping. Absent. However, in such a case, the conventional tactile sensing devices including Patent Document 1 and Patent Document 2 have room for improvement in terms of accurate detection of force.

  The present invention has been made in view of such a reason, and an object thereof is to provide a tactile detection device capable of accurately detecting a force even if the force from an object to be detected changes depending on the situation. There is to do.

  In order to achieve the above object, the tactile detection device according to claim 1 is a tactile detection device including a tactile detector, a tactile detection controller, and a measuring instrument, wherein the tactile detector has an inner space having an opening. And a base portion in which a supply path for supplying gas or liquid is formed, and the opening portion of the inner space portion are closed, and the base portion can expand according to the pressure of the gas or liquid in the inner space portion. A sheet portion and a sensor that detects an applied force, and is embedded in the sheet portion and can be tilted by expansion of the sheet portion. Gas or liquid is supplied to the inner space, and the measuring instrument measures a value detected by the sensor.

  The haptic detection device according to claim 2 is the haptic detection device according to claim 1, wherein the sheet portion is a separate member from the base portion.

  The haptic detection device according to claim 3 is the haptic detection device according to claim 2, wherein the sheet portion is higher in flexibility than the base portion.

  The haptic detection device according to claim 4 is the haptic detection device according to any one of claims 1 to 3, wherein the sensor is arranged so as to be shifted from a center of the opening of the inner space. It is characterized by that.

  The haptic detection device according to claim 5 is the haptic detection device according to any one of claims 1 to 4, wherein the sensor is one or more than one for the inner space portion. It is provided.

  According to the tactile sense detection device of the present invention, accurate detection of force is possible even if the force from an object that must be detected changes depending on the situation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically shows a tactile sensor according to an embodiment of the present invention, in which a tactile sensor is shown in a sectional view, and a tactile sensor controller and a measuring instrument are shown in a block diagram. FIG. 2 is an enlarged view of a tactile detector of the same tactile sense detection device, in which (a) is a plan view and (b) is a cross-sectional view cut along a section taken along line AA of (a). It is an enlarged view of the sensor of the same tactile sense detection device, wherein (a) is a plan view and (b) is a right side view. It is sectional drawing which shows typically when an object contacts the tactile sensor of the tactile sensor of the same as above, Comprising: When (a) grips an object, (b) is a time of maintaining the grip of an object. FIG. 2 shows a prototype of the above-described tactile sense detection device, in which (a) is a plan view and (b) is a cross-sectional view cut along a section taken along line AA in (a). The experimental state using the prototype of a tactile sense detection apparatus same as the above is shown, (a) is experiment 1, (b) is experiment 2a, (c) is sectional drawing which shows experiment 2b. It is a graph which shows the experimental result of Experiment 1 using the prototype of a tactile sense detection device same as the above. It is a graph which shows the experimental result of experiment 2a, 2b using the prototype of a tactile sense detection device same as the above, (a) is experiment 2a, (b) is about experiment 2b. It is a graph which shows the FET characteristic derived from the experimental result of experiment 2a, 2b using the prototype of a tactile sense detection device same as the above, (a) is experiment 2a, (b) is about experiment 2b.

  Hereinafter, modes for carrying out the present invention will be described. As shown in FIG. 1, the tactile sensing device 1 according to the embodiment of the present invention includes a tactile sensor 2, a tactile detection controller 6, and a measuring instrument 7. The tactile sensor 2 is provided in a gripping part RO such as a robot, and includes a base part 3, a sheet part 4, and a sensor 5. In the present embodiment, the base part 3 and the sheet part 4 are separate members.

  As shown in FIGS. 2A and 2B, the base portion 3 is formed with an inner space portion (chamber) 31 and a supply path 32. The base part 3 can be made of, for example, a silicone resin.

  The inner space portion 31 has an opening 31a. The inner space portion 31 can be rectangular or circular in plan view. The number and size of the inner space portions 31 can be variously changed according to the application of the tactile sense detection device 1.

  The supply path 32 communicates internally with the inner space portion 31, is connected to the tactile detection controller 6 via the tube 6 </ b> A, and supplies gas or liquid to the inner space portion 31.

  The sheet portion 4 is affixed to the surface of the base portion 3 and closes the opening portion 31 a of the inner space portion 31. The sheet portion 4 can expand according to the pressure of the gas or liquid in the inner space portion 31. More specifically, when the pressure of the gas or liquid in the inner space portion 31 is a predetermined value, the sheet portion 4 can be in a state where it does not substantially expand, and the sheet portion 4 expands as it becomes larger than the predetermined value. growing. The sheet portion 4 is thin and can be made of a material having higher flexibility than the base portion 3 so as to easily expand. The sheet part 4 can be made of, for example, a silicone resin having higher flexibility than the base part 3.

  The sensor 5 is embedded in the sheet part 4. The number of sensors 5 corresponding to the number of inner space portions 31 of the base portion 3 is provided.

  In this embodiment, the sensor 5 uses a strain gauge. As shown in FIGS. 3 (a) and 3 (b), the sensor 5 is generally a flat plate as a whole, and a metal gauge pattern 51 is formed on a resin-made gauge base 51 and a plane thereon. The resistive element 52, the two metal lead wires 53 and 53 soldered to the resistive element 52, and the resin laminate material covering the resistive element 52 and the lead wires 53 and 53 on the gauge base 51 54. The lead wires 53 are connected to the electrical wiring 7A.

  The sensor 5 detects the force applied to it. The detected value is measured by the measuring instrument 7 as will be described later. Specifically, the resistance element 52 is distorted and the resistance value is changed by the applied force, and the measuring instrument 7 measures the change in the resistance value through the two lead wires 53 and 53. In the present embodiment, the direction of the sensor 5 refers to the direction of the normal line of the plane on which the resistance element 52 is formed.

  The sensor 5 is arranged so as to be shifted from the center of the opening 31 a of the inner space portion 31. Therefore, the sensor 5 is inclined according to the expansion of the seat portion 4. In the present embodiment, when the sheet portion 4 is not substantially expanded, the orientation of the sensor 5 is perpendicular to the surface of the base portion 3. Then, as the expansion of the sheet part 4 increases, the direction of the sensor 5 is inclined from the direction perpendicular to the surface of the base part 3.

  When the sensor 5 tries to detect a force in a certain direction, the sensitivity is usually different depending on the direction of the sensor 5. When the grip part RO such as a robot grips the object M (when it is about to grip), the direction of the sensor 5 is the direction perpendicular to the surface of the base part 3 as shown in FIG. As a result, a force perpendicular to the surface of the base portion 3 can be easily detected. On the other hand, when a gripping unit such as a robot keeps gripping the object M, the direction of the sensor 5 is tilted from a direction perpendicular to the surface of the base unit 3 as shown in FIG. It is possible to easily detect the force in the direction in which the slid (smooth force parallel to the surface of the base portion 3).

  As described above, the tactile sense detection device 1 makes it possible to accurately detect the force even if the force from the object M to be detected changes according to the situation by making the direction of the sensor 5 movable. Further, the degree of inclination of the sensor 5 can be changed according to the type of the object M or according to the gripping state.

  The number of sensors 5 is not limited to one and may be two or more for one inner space portion 31. When there are two or more sensors 5, for example, they are symmetrically arranged from the center of the opening 31 a of the inner space portion 31 and applied when the object M can perform a one-dimensional reciprocating motion or a two-dimensional motion. Can be detected more easily.

  The tactile detection controller 6 supplies gas or liquid to the inner space 31 via the tube 6 </ b> A and the supply path 32. The tactile detection controller 6 is configured so that the orientation of the sensor 5 is perpendicular to the surface of the base portion 3 when the grasping portion RO such as a robot grasps the object M. , Gas or liquid is supplied under pressure. In addition, when a gripping unit such as a robot maintains gripping the object M, gas or liquid is used to hold the object M so that the direction of the sensor 5 is tilted from a direction perpendicular to the surface of the base unit 3. Is also supplied under pressure. In order to change the direction of the sensor 5, if the rigidity of the sheet portion 4 is low (if the flexibility is high), the change in pressure of the gas or liquid is relatively small, and if the rigidity is high (if the flexibility is low), the gas is changed. Or the change in the pressure of the liquid is relatively large. Further, the pressure of the gas or liquid supplied to the inner space portion 31 can be changed for each of the plurality of inner space portions 31, or all of the plurality of inner space portions 31 can be made common. . In the latter case, the tactile detection controller 6 can be configured such that one tube 6 </ b> A is connected and branched in the middle to be connected to the supply path 32.

  The measuring instrument 7 measures the value detected by the sensor 5 via the electrical wiring 7A. An existing general circuit corresponding to the sensor 5 can be applied to the measuring instrument 7.

  As described above, the tactile sense detection device 1 can change the direction of the sensor 5 according to the direction of the applied force depending on whether the holding unit RO such as a robot holds the object M or maintains the holding. Therefore, characteristics such as sensitivity of the sensor 5 can be preferably used.

  Next, an experiment using a prototype of the tactile sensing device 1 manufactured by the present inventor will be described.

  FIGS. 5A and 5B show this prototype. The outer shape of the base part 3 is a rectangular parallelepiped having a size of 40 mm in length, 50 mm in width, and 10 mm in height. Two rectangular inner space portions 31 are formed on the surface of the base portion 3 (surface of 40 mm length and 50 mm width) in plan view. The inner space portion 31 has a size of 30 mm in length, 10 mm in width, and 6 mm in height. Further, a supply path 32 communicating with the inner space portion 31 is formed. The seat part 4 is made of a material having higher flexibility than the base part 3. The sheet portion 4 is bonded to the base portion 3 so as to cover the entire surface of the base portion 3 including the two inner space portions 31. In FIG. 5A, the vertical direction is the vertical direction, the horizontal direction is the horizontal direction, and in FIG. 5B, the height is the vertical direction.

  The sensor 5 is disposed above each opening 31a of the inner space 31 so as to be shifted in one direction from the center of the opening 31a (to the right in FIGS. 5A and 5B).

The base part 3 was produced by injecting a silicone resin (trade name Dragon Skin ^R 20 manufactured by SMOOTH-ON) into a mold. The sheet part 4 in which the sensor 5 was embedded was manufactured as follows. First, a 1 mm thin liquid layer of silicone resin (trade name Ecoflex ^R 10 manufactured by SMOOTH-ON) was solidified halfway, and a strain gauge sensor 5 manufactured by Kyowa Denki Co., Ltd. was placed at a predetermined position. On top of that, the same silicone resin liquid was poured and left to solidify completely.

   Experiments (experiment 1 and experiment 2) using the prototype of the tactile sensing device 1 are as follows.

  First, Experiment 1 is described. In Experiment 1, the orientation of the sensor 5 is perpendicular to the surface of the base portion 3. In this case, the tactile detection controller 6 supplies air to the inner space 31 with an air pressure of 0.01 MPa. In order to simulate the force applied from the object M when grasping, a spherical roller C is arranged as shown in FIG. A pulsed force of 0 to 5N was regularly applied perpendicularly to the surface of the sheet part 4 (base part 3). The measuring instrument 7 was set to a measurement speed of 500 Hz, and output a voltage value amplified and converted into digital data.

FIG. 7 shows the results of Experiment 1. It can be seen that the sensor 5 accurately (sensitively) detects the force generated by the roller C.

  Next, Experiment 2 will be described. In Experiment 2, in Experiment 2a, the direction of the sensor 5 is tilted from the direction perpendicular to the surface of the base portion 3. In this case, the tactile detection controller 6 supplies air to the inner space 31 with an air pressure of 0.05 MPa. In Experiment 2b, the orientation of the sensor 5 is perpendicular to the surface of the base portion 3. In this case, the tactile detection controller 6 supplies air to the inner space 31 with an air pressure of 0.01 MPa. In Experiment 2a and Experiment 2b, a spherical roller C is disposed as shown in FIGS. 6B and 6C in order to simulate the force in the sliding direction applied from the object M when maintaining gripping. The reciprocating travel was performed from end to end while rotating on the sheet portion 4 at a cycle of 4 Hz. The measuring instrument 7 was set to a measurement speed of 500 Hz, and output a voltage value amplified and converted into digital data.

  In FIG. 8, (a) shows the experimental result of Experiment 2a, and (b) shows the experimental result of Experiment 2b. Comparing FIG. 8A and FIG. 8B, it can be seen that (a) accurately (sensitively) detects the force generated by the roller C.

  In FIG. 9, (a) shows the FET characteristics of the experimental results of Experiment 2a, and (b) shows the FET characteristics of the experimental results of Experiment 2b. In (a), since the rotation speed of the roller C is 4 Hz, a peak appears remarkably at this frequency. In (b), the peak at 4 Hz cannot be clearly distinguished from other frequency components.

  As described above, the experiment (experiment 1 and experiment 2) using the prototype of the tactile sense detection device 1 varies the direction of the sensor 5 according to the direction of the applied force, and thereby the characteristics such as the sensitivity of the sensor 5 are improved. It can be used suitably, and it can be seen that it is possible to detect a force according to the situation (when holding the object M and when holding the object M).

  The tactile sense detection device according to the embodiment of the present invention has been described above, but the present invention is not limited to the one described in the embodiment, and various design modifications within the scope of the matters described in the claims. Is possible. For example, the base portion 3 and the seat portion 4 can be integrally formed with one member depending on circumstances. The sensor 5 may be a sensor other than a strain gauge.

DESCRIPTION OF SYMBOLS 1 Tactile sensor 2 Tactile sensor 3 Base part 31 Inner space part 31a Opening part of inner space part 32 Supply path 4 Sheet | seat part 5 Sensor 51 Gauge base 52 Resistance element 53 Lead wire 54 Laminating material 6 Tactile sensor controller 6A Tube 7 Measuring instrument 7A Electrical wiring C Spherical roller M Article RO Gripping part

Claims (5)

In a tactile detection device comprising a tactile detector, a tactile detection controller, and a measuring instrument,
The tactile detector is
An inner space part having an opening part and a base part in which a supply path for supplying gas or liquid is formed,
A sheet portion that closes the opening of the inner space portion and can expand according to the pressure of gas or liquid in the inner space portion;
A sensor that detects the applied force, and is embedded in the sheet part and can tilt by expansion of the sheet part, and
The tactile detection controller supplies gas or liquid from the supply path to the inner space,
The tactile sensing device, wherein the measuring device measures a value detected by the sensor. The tactile sensing device according to claim 1,
The tactile sense detection device, wherein the sheet portion is a separate member from the base portion. The tactile sensing device according to claim 2,
The tactile sensing device according to claim 1, wherein the sheet portion is more flexible than the base portion. In the tactile sense detection device according to any one of claims 1 to 3,
The tactile sensing device according to claim 1, wherein the sensor is arranged so as to be shifted from a center of the opening of the inner space. In the tactile sense detection device according to any one of claims 1 to 4,
One or two or more sensors are provided for one inner space, and the tactile sense detection device.

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