JP2017102593A - Control device, machine tool, control method, and computer program - Google Patents

Abstract

The present invention provides a control device, a machine tool, and a computer program that can form a smooth curved surface on a workpiece. A control device that sets a machining path based on a plurality of command points indicating the position of a spindle, and controls movement of the spindle based on the machining path, includes a plurality of evaluations that intersect the machining path. a setting unit that sets a cross section so that the number of command points existing between two adjacent evaluation cross sections is equal to or less than a threshold; and a calculation that calculates an intersection of the evaluation cross section set by the setting unit and the machining path. an intersection point position correction unit that corrects the position of the intersection calculated by the calculation unit; and a position of the command point in the direction intersecting the machining path based on the intersection corrected by the intersection position correction unit. A control device comprising a command point position correction section. [Selection diagram] Figure 7

Description

  The present invention relates to a control device, a machine tool, and a computer program for controlling movement of a spindle on which a tool is mounted.

  The machine tool includes a control device that controls movement of a spindle on which a tool is mounted. The control device sets a plurality of command points that indicate the position of the spindle and sets a machining path. When the tool mounted on the spindle forms a three-dimensional curved surface on the workpiece, the control device calculates and generates a plurality of curves in which minute line segments between command points are continuous.

  For example, a plurality of curves are generated on a plane (horizontal plane) parallel to the front-rear direction and the left-right direction. The plurality of curves are arranged in the front-rear direction or the left-right direction. The control device sets a vertical position for each curve. Further, the control device interpolates the generated curve based on a smooth curve such as a spline curve or a Bezier curve because a sharp portion appears at the joint of the minute line segment. At each set vertical position, the main axis moves along the interpolated curve to process the workpiece (see, for example, Patent Document 1).

Japanese Patent No. 3466111

  However, even when the above-described interpolation is performed, a scale-like pattern appears on the workpiece surface due to a difference in slope between adjacent curves, a quantization error generated by calculation in the control device, and the like. In Patent Document 1, new command points are inserted between command points so as to form a smooth line without correcting the command points. Therefore, although the command point itself is wrong, it passes through the command point, and there is a problem that a scale-like pattern appears on the surface of the workpiece.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a control device, a machine tool, and a computer program that can form a smooth curved surface on a workpiece.

  A control device according to the present invention sets a machining path based on a plurality of command points that indicate a position of a spindle, and controls the movement of the spindle based on the machining path. A setting unit for setting a plurality of evaluation cross sections to be set so that the number of the command points existing between two adjacent evaluation cross sections is equal to or less than a threshold value, and an intersection of the evaluation cross section set by the setting unit and the machining path Based on the intersection point corrected by the intersection position correction unit, the intersection position correction unit that corrects the position of the intersection calculated by the calculation unit, and the command point in the direction intersecting the machining path And a command point position correcting unit for correcting the position.

  In the control device according to the present invention, after the setting unit sets the evaluation cross section at a predetermined interval in the machining path, the number of the command points existing between two adjacent evaluation cross sections is a threshold value. And when determining that the number of the command points existing between two adjacent evaluation sections exceeds the threshold, And an additional setting unit for adding an evaluation cross section between the two evaluation cross sections.

  The control device according to the present invention is characterized in that the additional setting unit adds an evaluation cross section at the center between the two evaluation cross sections.

  In the control device according to the present invention, the plurality of command points include a first command point and a second command point located next to the first command point, and the setting unit includes the first command point and the first command point. A first setting unit that sets one evaluation section between two command points, a third command point that is separated from the first command point by a distance corresponding to the threshold value, and a third command point that is located next to the third command point. A second setting unit for setting four command points; and a third setting unit for setting the other evaluation section between the third command point and the fourth command point set by the second setting unit. It is characterized by.

  In the control device according to the present invention, the first setting unit sets the one evaluation section at a center between the first command point and the second command point, and the third setting unit includes the third command point. The other evaluation section is set in the center between the point and the fourth command point.

  A machine tool according to the present invention includes any one of the control devices described above and the spindle.

  A control method according to the present invention sets a machining path based on a plurality of command points that indicate the position of a spindle, and controls the movement of the spindle based on the machining path. A plurality of evaluation sections to be set so that the number of the command points existing between two adjacent evaluation sections is equal to or less than a threshold value, and the intersection of the set evaluation section and the machining path is calculated, and the calculation unit The position of the intersection calculated by is corrected, and the position of the command point in the direction intersecting the machining path is corrected based on the corrected intersection.

  The computer program according to the present invention can be executed by a control device that sets a machining path based on a plurality of command points for instructing the position of the spindle according to the machining program and controls the movement of the spindle based on the machining path. In this computer program, the control device sets a plurality of evaluation sections intersecting the machining path so that the number of the command points existing between the two adjacent evaluation sections is equal to or less than a threshold value, Based on the calculation section that calculates the intersection of the evaluation section and the machining path set by the setting section, the intersection position correction section that corrects the position of the intersection calculated by the calculation section, and the intersection corrected by the intersection position correction section , And functioning as a command point position correcting unit that corrects the position of the command point in a direction intersecting the machining path.

  In the present invention, an evaluation cross section that intersects the machining path is set, the position of the intersection of the evaluation cross section and the machining path is corrected, and the position of the command point in the direction that intersects the machining path based on the corrected position of the intersection To correct. Further, the number of command points existing between two adjacent evaluation sections is set to be equal to or less than a threshold value.

  In the present invention, after setting the evaluation cross section, it is determined whether the number of command points existing between two adjacent evaluation cross sections exceeds a threshold value. If the number of command points exceeds the threshold value, a new evaluation section is added between two adjacent evaluation sections.

  In the present invention, a new evaluation cross section is added at the center between two adjacent evaluation cross sections to prevent the number of evaluation cross sections from increasing more than necessary.

  In the present invention, one evaluation section is set between the first command point and the second command point, and the third command point arranged at a position separated from the first command point by a threshold number is designated. Then, another evaluation cross section is set between the third command point and the fourth command point located next to the third command point. It is possible to prevent the number of evaluation sections from becoming too small or too large, and to prevent a decrease in accuracy of position correction with respect to the command point and an increase in calculation amount.

  In the present invention, one evaluation section is set at the center between the first command point and the second command point, and another evaluation section is set at the center between the third command point and the fourth command point. A large number of evaluation sections can be set.

  In the control device, machine tool, control method, and control program according to the present invention, an evaluation cross section that intersects the machining path is set, the position of the intersection of the evaluation cross section and the machining path is corrected, and the corrected intersection position is set. Based on this, the position of the command point in the direction intersecting the machining path is corrected. Even in the direction intersecting the machining path, the position of the command point can be corrected, so that a smooth curved surface can be formed on the workpiece. In addition, since the number of command points existing between two adjacent evaluation cross sections is equal to or less than the threshold value, the number of evaluation cross sections relative to the number of command points becomes too small, and the accuracy of position correction with respect to the command points is prevented from being lowered. .

1 is a perspective view schematically showing a machine tool according to a first embodiment. It is a block diagram which briefly shows the structure of a control apparatus. It is a top view which shows schematically the processing path with respect to a workpiece | work, and evaluation cross section. It is a perspective view which briefly shows the evaluation section to a work. It is a flowchart explaining the process route setting process by a control apparatus. It is a flowchart explaining an evaluation cross section addition process. It is a schematic diagram which shows a command point and the intersection of an evaluation cross section and a process path | route schematically. It is a conceptual diagram which shows an example of an intersection table. It is explanatory drawing explaining the 1st correction method of the intersection position on an evaluation cross section. It is explanatory drawing explaining the 2nd correction method of the intersection position on an evaluation cross section. It is explanatory drawing explaining the correction method of a command point. It is a flowchart explaining a command point position correction process. FIG. 10 is a plan view schematically showing a machining path and an evaluation cross section for a workpiece in the second embodiment. It is a flowchart explaining the process route setting process by a control apparatus. It is a flowchart explaining an outermost periphery / innermost periphery calculation process. FIG. 5 is a schematic view schematically showing a machining path of a main shaft moving in a spiral shape from the outer peripheral side to the inner peripheral side. FIG. 5 is a schematic view schematically showing a machining path of a main shaft moving in a spiral shape from the inner peripheral side to the outer peripheral side. It is a flowchart explaining an evaluation cross-section setting process. It is a schematic diagram explaining an evaluation cross-section setting process. It is a schematic diagram which shows a command point and the intersection of an evaluation cross section and a process path | route schematically. 10 is a flowchart for explaining machining path setting processing by the control device in the third embodiment. It is a flowchart explaining a 2nd evaluation cross-section setting process. It is a schematic diagram explaining a 2nd evaluation cross-section setting process. It is a top view which shows schematically the processing path with respect to the workpiece | work in the example of a change, and an evaluation cross section.

(Embodiment 1)
Hereinafter, the present invention will be described with reference to the drawings showing a machine tool according to a first embodiment. In the following description, up and down, left and right, and front and rear indicated by arrows in the figure are used. FIG. 1 is a perspective view schematically showing a machine tool.

  The machine tool 100 includes a rectangular base 1 extending forward and backward. A work holding unit 3 that holds a work is provided on the front side of the upper portion of the base 1. The work holding unit 3 can rotate around the A axis with the left-right direction as the axial direction and the C axis with the up-down direction as the axial direction.

  A support base 2 for supporting a column 4 described later is provided on the rear side of the upper part of the base 1. A Y-axis direction moving mechanism 10 for moving the moving plate 16 in the front-rear direction is provided on the support base 2. The Y-axis direction moving mechanism 10 includes two rails 11 extending in the front-rear direction, a Y-axis screw shaft 12, a Y-axis motor 13, and a bearing 14.

  The rails 11 are provided on the left and right of the upper part of the support base 2, respectively. The Y-axis screw shaft 12 extends in the front-rear direction and is provided between the two rails 11. A bearing 14 is provided at each of the front end portion and the middle portion of the Y-axis screw shaft 12. In addition, illustration of the bearing provided in the middle part is abbreviate | omitted. The Y-axis motor 13 is connected to the rear end portion of the Y-axis screw shaft 12.

  A nut (not shown) is screwed onto the Y-axis screw shaft 12 via a rolling element (not shown). The rolling element is, for example, a ball. A plurality of sliders 15 are slidably provided on each rail 11. A moving plate 16 is connected to the upper part of the nut and the slider 15. The moving plate 16 extends in the horizontal direction. As the Y-axis motor 13 rotates, the Y-axis screw shaft 12 rotates, the nut moves in the front-rear direction, and the moving plate 16 moves in the front-rear direction.

  An X-axis direction moving mechanism 20 that moves the column 4 in the left-right direction is provided on the upper surface of the moving plate 16. The X-axis direction moving mechanism 20 includes two rails 21 extending left and right, an X-axis screw shaft 22, an X-axis motor 23 (see FIG. 2), and a bearing 24.

  The rails 21 are provided at the front and rear sides of the upper surface of the movable plate 16. The X-axis screw shaft 22 extends left and right and is provided between the two rails 21. A bearing 24 is provided at each of the left end portion and midway portion of the X-axis screw shaft 22. In addition, description of the bearing provided in the middle part of the X-axis screw shaft 22 is abbreviate | omitted. The X-axis motor 23 is connected to the rear end portion of the X-axis screw shaft 22.

  A nut (not shown) is screwed onto the X-axis screw shaft 22 via a rolling element (not shown). Grease is applied to the X-axis screw shaft 22. A plurality of sliders 26 are slidably provided on each rail 21. The column 4 is connected to the upper part of the nut and the slider 26. Column 4 is columnar. As the X-axis motor 23 rotates, the X-axis screw shaft 22 rotates, the nut moves in the left-right direction, and the column 4 moves in the left-right direction.

  A Z-axis direction moving mechanism 30 for moving the spindle head 5 in the vertical direction is provided on the front surface of the column 4. The Z-axis direction moving mechanism 30 includes two rails 31 extending vertically, a Z-axis screw shaft 32, a Z-axis motor 33, and a bearing 34.

  The rails 31 are provided on the left and right sides of the front surface of the column 4, respectively. The Z-axis screw shaft 32 extends vertically and is provided between the two rails 31. A bearing 34 is provided at each of a lower end portion and a midway portion of the Z-axis screw shaft 32. In addition, illustration of the bearing provided in the middle part is abbreviate | omitted. The Z-axis motor 33 is connected to the upper end portion of the Z-axis screw shaft 32.

  A nut (not shown) is screwed onto the Z-axis screw shaft 32 via a rolling element (not shown). Grease is applied to the Z-axis screw shaft 32. A plurality of sliders 35 are slidably provided on each rail 31. The spindle head 5 is connected to the front part of the nut and the slider 35. The Z-axis screw shaft 32 is rotated by the rotation of the Z-axis motor 33, the nut moves in the vertical direction, and the spindle head 5 moves in the vertical direction. The Z-axis motor 33, the Z-axis screw shaft 32, the nut and the rolling element constitute a ball screw mechanism.

  A main shaft 5 a extending vertically is provided in the main shaft head 5. The main shaft 5a rotates around the axis. A spindle motor 6 is provided at the upper end of the spindle head 5. A tool is attached to the lower end of the main shaft 5a. The spindle 5a is rotated by the rotation of the spindle motor 6, and the tool is rotated. The rotated tool processes the workpiece held in the workpiece holding unit 3.

  The machine tool 100 includes a tool changer (not shown) that changes tools. The tool changer exchanges a tool housed in a tool magazine (not shown) and a tool mounted on the spindle 5a.

FIG. 2 is a block diagram schematically showing the configuration of the control device 50. The control device 50 includes a CPU 51, a storage unit 52, a RAM 53, and an input / output interface 54. The storage unit 52 is a rewritable memory, such as an EPROM or an EEPROM. The storage unit 52 stores an intersection table, a path number i, a command point P _k , an intersection point S _i ^d , a final number of k, a variable c, a variable m, a first reference point O _m , a second reference point L _m , and the like which will be described later. Store (c, d, i, k, m are natural numbers).

  When the operator operates the operation unit 7, a signal is input from the operation unit 7 to the input / output interface 54. The operation unit 7 is a keyboard, a button, a touch panel, or the like, for example. The input / output interface 54 outputs a signal to the display unit 8. The display unit 8 displays characters, figures, symbols, and the like. The display unit 8 is, for example, a liquid crystal display panel.

  The control device 50 includes an X-axis control circuit 55 corresponding to the X-axis motor 23, a servo amplifier 55a, and a differentiator 23b. The X-axis motor 23 includes an encoder 23a. The X-axis control circuit 55 outputs a command indicating the amount of current to the servo amplifier 55a based on a command from the CPU 51. The servo amplifier 55a receives the command and outputs a drive current to the X-axis motor 23.

  The encoder 23 a outputs a position feedback signal to the X-axis control circuit 55. The X-axis control circuit 55 performs position feedback control based on the position feedback signal.

  The encoder 23a outputs a position feedback signal to the differentiator 23b, and the differentiator 23b converts the position feedback signal into a speed feedback signal and outputs it to the X-axis control circuit 55. The X-axis control circuit 55 performs speed feedback control based on the speed feedback signal.

  The current detector 55b detects the value of the drive current output from the servo amplifier 55a. The current detector 55 b feeds back the value of the drive current to the X axis control circuit 55. The X axis control circuit 55 executes current control based on the value of the drive current.

  The control device 50 includes a Y-axis control circuit 56 corresponding to the Y-axis motor 13, a servo amplifier 56a, and a differentiator 13b. The Y-axis motor 13 includes an encoder 13a. Based on the command from the CPU 51, the Y-axis control circuit 56 outputs a command indicating the current amount to the servo amplifier 56a. The servo amplifier 56 a receives the command and outputs a drive current to the Y-axis motor 13.

  The encoder 13 a outputs a position feedback signal to the Y-axis control circuit 56. The Y-axis control circuit 56 performs position feedback control based on the position feedback signal.

  The encoder 13a outputs a position feedback signal to the differentiator 13b, and the differentiator 13b converts the position feedback signal into a speed feedback signal and outputs it to the Y-axis control circuit 56. The Y-axis control circuit 56 executes speed feedback control based on the speed feedback signal.

  The current detector 56b detects the value of the drive current output from the servo amplifier 56a. The current detector 56 b feeds back the drive current value to the Y-axis control circuit 56. The Y axis control circuit 56 executes current control based on the value of the drive current.

  The control device 50 includes a Z-axis control circuit 57 corresponding to the Z-axis motor 33, a servo amplifier 57a, and a differentiator 33b. The Z-axis motor 33 includes an encoder 33a. Based on the command from the CPU 51, the Z-axis control circuit 57 outputs a command indicating the amount of current to the servo amplifier 57a. The servo amplifier 57a receives the command and outputs a drive current to the Z-axis motor 33.

  The encoder 33 a outputs a position feedback signal to the Z-axis control circuit 57. The Z-axis control circuit 57 performs position feedback control based on the position feedback signal.

  The encoder 33a outputs a position feedback signal to the differentiator 33b, and the differentiator 33b converts the position feedback signal into a speed feedback signal and outputs it to the Z-axis control circuit 57. The Z-axis control circuit 57 performs speed feedback control based on the speed feedback signal.

  The current detector 57b detects the value of the drive current output from the servo amplifier 57a. The current detector 57 b feeds back the value of the drive current to the Z-axis control circuit 57. The Z-axis control circuit 57 executes current control based on the drive current value.

  The control device 50 also performs feedback control similar to that of the X to Z axis motors 23, 13, and 33 with respect to the spindle motor 6.

  The machine tool 100 includes a magazine motor 60 and a magazine control circuit 58. The tool magazine is driven by the rotation of the magazine motor 60. The magazine control circuit 58 controls the rotation of the magazine motor 60.

The storage unit 52 stores a machining program for machining a workpiece. The machining program has a plurality of command points P _k that indicate the position of the spindle 5a. k indicates the order of instructions constituting the machining program. The spindle 5a sequentially moves a plurality of command points _Pk , and the tool mounted on the spindle 5a processes the workpiece.

The storage unit 52 stores a command point P _k in advance. The control device 50 sets a path (machining path) along which the spindle 5a moves based on the plurality of command points _Pk . The control device 50 executes the movement of the main shaft 5a based on the machining path.

A processing path setting method will be described. FIG. 3 is a plan view schematically showing a machining path and an evaluation cross section for the work, and FIG. 4 is a perspective view schematically showing an evaluation cross section for the work. In the figure, the X direction indicates the left-right direction, the Y direction indicates the front-rear direction, and the Z direction indicates the up-down direction. Further, the shape of the workpiece in FIGS. 3 and 4 indicates the shape after processing, and the dotted line indicates the evaluation section D ^d . The arrows in FIG. 3 indicate the machining path.

The control device 50 sets an evaluation section D ^d (d indicates a section number and is a natural number) for the workpiece. As shown in FIG. 3, when the main shaft 5a largely reciprocates along the X direction, the machining path is a path along the X direction. As shown in FIG. 3, the control device 50 sets a plurality of evaluation sections D ^d along a direction substantially orthogonal to the machining path. The plurality of evaluation sections D ^d are arranged in the X direction. The operator instructs in advance that the machining path is in the X direction.

  The control device 50 executes a machining path setting process. FIG. 5 is a flowchart for explaining the machining path setting process by the control device 50.

  The CPU 51 of the control device 50 stands by until a start signal is input (step S1: NO). For example, the user operates the operation unit 7 to input a start signal to the control device.

If there is an input of the start signal (Step S1: YES), CPU 51 sets a plurality of evaluation section D ^d to the machining path (Step S2). The CPU 51 sets a plurality of evaluation sections D ^d at equal intervals. The setting start position and end position of the evaluation section D ^d may be set in advance by the user, or may be automatically set from the machining path.

  The CPU 51 executes an evaluation cross section addition process (step S3), executes a command point position correction process (step S4), and ends the machining path setting process. Details of the evaluation section addition processing and the command point position correction processing will be described later.

The evaluation section addition process will be described. FIG. 6 is a flowchart for explaining the evaluation cross section addition process, and FIG. 7 is a schematic diagram schematically showing the command point P _k , the intersection of the evaluation cross section D ^d and the machining path. ● The command point, ○ intersection evaluation section D ^d and the processing path, arrow machining path, a dotted line indicates respectively the evaluation section D ^d.

The CPU 51 sets 1 to the cross section number d (step S11). The CPU 51 calculates the command point number M _d between the evaluation sections D ^d -D ^{d + 1} (step S12).

The CPU 51 determines whether or not the command score M _d exceeds the threshold value T (step S13). When the command point number M _d does not exceed the threshold T (step S13: NO), the CPU 51 increments the cross-section number d by one (step S18), and determines whether the cross-section number d is the final number. (Step S19).

  When the section number d is not the final number (step S19: NO), the CPU 51 returns the process to step S12. When the section number d is the final number (step S19: YES), the CPU 51 reassigns the section number d (step S20) and returns to the processing path setting process (see FIG. 5).

When the command score M _d exceeds the threshold value T (step S13: YES), the CPU 51 adds a ^new evaluation section D ^new at the center between the evaluation sections D ^d -D ^{d + 1} (step S14, (See FIG. 7).

The CPU 51 calculates the number of command points between adjacent evaluation sections between the evaluation sections D ^d -D ^{d + 1} (step S15). For example, when the evaluation cross section D ^new is added between the evaluation cross sections D ^d -D ^{d + 1} , the number of command points between the evaluation cross sections D ^d -D ^new and the number of command points between the evaluation cross sections D ^new -D ^{d + 1} And

The CPU 51 determines whether or not there is a command score that exceeds the threshold T for each command score (step S16). When there are command points that exceed the threshold T (step S16: YES), the CPU 51 selects two evaluation sections that sandwich the command points P _k that exceed the threshold T (step S17). The CPU 51 returns the process to step S14, and sets a new evaluation section at the center of the two selected evaluation sections.

For example, when the number of command points between the evaluation sections D ^{d and} D ^new exceeds the threshold T, the CPU 51 further adds a new evaluation section between the evaluation sections D ^{d and} D ^new .

  If there is no command point exceeding the threshold T (step S16: NO), the CPU 51 increments the cross-section number d by one (step S18), and determines whether the cross-section number d is the final number (step S18). S19).

  When the section number d is not the final number (step S19: NO), the CPU 51 returns the process to step S12. When the section number d is the final number (step S19: YES), the CPU 51 reassigns the section number d (step S20) and returns to the processing path setting process (see FIG. 5).

Step S20 will be described. As shown in FIG. 7, when the evaluation section D ^new is added between the evaluation sections D ^d -D ^{d + 1} and the section number d is reassigned, the evaluation section D ^new becomes the evaluation section ^{d + 1.} Thus, the evaluation cross section ^{d + 1} becomes the evaluation cross section ^{d + 2} (see parentheses in FIG. 7).

  In step S14, a new evaluation section is added at the center between two adjacent evaluation sections. However, a new evaluation section may be added at a position other than the center between the two evaluation sections. .

  The command point position correction process will be described. In FIG. 7, “i” (i is a natural number) indicates a path number in the movement of the main shaft 5a in the X direction. As shown in FIG. 7, for example, a route with route number 1 (i = 1) indicates a route that moves from left to right, and a route with route number 2 (i = 2) wraps the route with route number 1 at the right end. The route from right to left is shown. The same applies to route numbers 3 and below. The main shaft 5a moves in the order of route numbers.

FIG. 8 is a conceptual diagram showing an example of the intersection table. As shown in FIG. 8, the control device 50 calculates an intersection S _i ^d with the movement path P _k −P _{k + 1} in each evaluation section D ^d , and calculates the path number i, the intersection coordinates S _i ^d, and the movement path. P _k −P _{k + 1} is associated and stored in the intersection table.

Controller 50 corrects the intersection position on the evaluation section D ^d for example, the first correction method. Figure 9 is an explanatory diagram for explaining a first method of correcting the intersection position on the evaluation section D ^d. For example, the controller 50 corrects the coordinates in the Z direction so as to gradually change. Correction point t using the intersection coordinates s _i-2 ^d , s _i-1 ^d , s _{i + 1} ^d , s _{i + 2} ^d of the two points before and after the intersection coordinate S _i ^d to be corrected _i ^d is determined.

Each Z coordinate value of the four intersection coordinates s _i-2 ^d , s _i-1 ^d , s _{i + 1} ^d , s _{i + 2} ^d is expressed as z _i-2 , z _i-1 , z _{i + 1} , z _{i. +2} and the Z coordinate value of the correction point t _i ^d is z _i ′, and the difference between the Z coordinate values is d ₁ = z _i−2 −z _i−1 , d ₂ = z _i−1 −z _i ′, d ₃ = z _i ′ −z _{i + 1} , d ₄ = z _{i + 1} −z _{i + 2,} and Z coordinate value double difference d ₁₂ ′, d ₂₃ ′, d ₃₄ ′ (Z coordinate value difference) z _i ′ is calculated such that the difference between d ₁ , d ₂ , d ₃ , and d ₄ ) changes linearly.

The two-time differences d ₁₂ ′, d ₂₃ ′, and d ₃₄ ′ of the Z coordinate value are obtained by the following equations.
d ₁₂ ′ = d ₂ −d ₁ = (z _i−1 −z _i ′) − (z _i−2 −z _i−1 ) = 2 z _i−1 −z _i ′ −z _i−2. 1)
d ₂₃ ′ = d ₃ −d ₂ = (z _i ′ −z _{i + 1} ) − (z _i−1 −z _i ′) = 2 z _i ′ −z _{i + 1} −z _i−1 (2) )
d ₃₄ ′ = d ₄ −d ₃ = (z _{i + 1} −z _{i + 2} ) − (z _i ′ −z _{i + 1} ) = 2 z _{i + 1} −z _{i + 2} −z _i ′ ... (3)

Since these change linearly,
d ₂₃ ′ = (d ₁₂ ′ + d ₃₄ ′) / 2 ... (4)
Meet.

Solving z _i ′ based on the equations (1) to (4),
z _i ′ = (− z _i−2 + 4z _i−1 + 4z _{i + 1} −z _{i + 2} ) / 6
It becomes.

Performing the modification for all intersections S _i ^d on evaluation section D ^d. Note that it is also possible to correct only intersections whose Z coordinate values are far apart compared to the Z coordinate values of other intersections.

Controller 50 corrects the intersection position on the evaluation section D ^d for example in the second correction method. FIG. 10 is an explanatory diagram for explaining a second correction method of the intersection position on the evaluation cross section. In FIG. 10, u corresponds to XY coordinates, and v corresponds to Z coordinates. The control device 50 creates a smooth curve (spline curve, Bezier curve, NURBS curve, etc.) using, for example, a plurality of other intersections around the intersection S _i ^d to be corrected, Project the intersection S _i ^d to be corrected.

When the four intersections s _i-2 ^d , s _i-1 ^d , s _{i + 1} ^d , s _{i + 2} ^d are used as smooth curves, the section s _i-2 on the evaluation section D ^d (uv plane) ^{d to} s _i-1 ^d , sections s _i-1 ^{d to} s _{i + 1} ^d , sections s _{i + 1} ^{d to} s _{i + 2} ^d , respectively, v ₁ (u), v ₂ (u), v ₃ (u) is represented by the following equation.
v _j (u) = a _j (u−u _j ) ³ + b _j (u−u _j ) ² + c _j (u−u _j ) + d _j
(J = 1, 2, 3)

Based on the fact that the first and second derivatives at the boundary points are continuous, passing through the intersections s _i-2 ^d , s _i-1 ^d , s _{i + 1} ^d , s _{i + 2} ^d 50 can determine a _{j to} d _j .

The selection of the four intersection points is not limited to the case of using two consecutive points located on both sides of the intersection point S _i ^d as described above. For example, intersection points may be selected discontinuously at every two points, such as intersection points s _i-3 ^d , s _i-1 ^d , s _{i + 1} ^d , and s _{i + 3} ^d .

As shown in FIG. 10, the correction point t _i ^d position is a position on the smooth curve where the distance from the intersection S _i ^d to be corrected is the minimum.

The corrected intersection group S ^d existing on the d-th evaluation section D ^{d is} defined as T ^d .
T ^d = {t _i ^d | d: section number, i: route number}

The control device 50 corrects the position of the command point by using the intersection point group ^Td . FIG. 11 is an explanatory diagram for explaining a method of correcting a command point. In FIG. 11, P _{a to} P _f are command points, ◯ is an intersection of the machining path and the evaluation section D ^d , and an arrow indicates the machining path.

For example, when the command point P _c is a correction target, as shown in FIG. 11A, the command point P _c is located between the cross section D ^d−1 and the cross section D ^d , and the path number is i. The control device 50 refers to the intersection table described above, and acquires the cross-sectional position and path number regarding the command point _Pc .

As shown in FIG. 11B, the control device 50 has intersections around the command point P _c , for example, four intersection points t _i ^{d + 1} , t _i ^d , t _i ^d−1 , t _i ^d− aligned on the machining path. Search for ² . The control device 50 creates a smooth curve (spline curve, Bezier curve, NURBS curve, etc.) from the four intersection points t _i ^{d + 1} , t _i ^d , t _i ^d-1 , t _i ^d-2 , The command point P _c is projected onto the image, and the correction point P _c ′ is determined. The control device 50 obtains a smooth curve by a method similar to the second correction method described above. The position of the correction point P _c ′ is a position where the distance from the command point P _c is minimum on a smooth curve. The control device 50 similarly corrects the positions of the other command points.

  FIG. 12 is a flowchart for explaining the command point position correction process. The CPU 51 creates the intersection point table (see FIGS. 7 and 8) after executing the above-described evaluation section addition processing (see FIGS. 5 and 6). Specifically, the CPU 51 sets “1” to the variable i indicating the path number of the reciprocating operation and the variable k indicating the order of the instructions constituting the machining program (step S21).

CPU51 reads movement path | route _{Pk- Pk + 1} (step S22). The CPU 51 determines whether or not the travel route P _k −P _{k + 1} intersects the evaluation section D ^d (step S23). When the movement route P _k -P _{k + 1} does not intersect the evaluation section D ^d (step S23: NO), the CPU 51 increments k by one (step S27).

When the movement path P _k -P _{k + 1} intersects with the evaluation section D ^d (step S23: YES), the CPU 51 has already reached the intersection S _i ^d between the evaluation section D ^d and the movement path P _k -P _{k + 1.} It is determined whether or not it exists (step S24).

When the intersection S _i ^d between the evaluation section D ^d and the movement path P _k −P _{k + 1} does not already exist (step S24: NO), the CPU 51 stores the path in the intersection table (see FIG. 8) in the storage unit 52. The number i, the intersection coordinates S _i ^d, and the movement route P _k -P _{k + 1} are stored in association with each other (step S26).

When the intersection S _i ^d between the evaluation section D ^d and the movement path P _k −P _{k + 1} already exists (step S24: YES), the CPU 51 increments i by one (step S25), and the CPU 51 stores the value. In the intersection table of the unit 52, the path number i, the intersection coordinates S _i ^d and the movement path P _k -P _{k + 1} are stored in association with each other (step S26), and k is incremented by one (step S27). Steps S21 to S27 constitute a calculation unit.

  After incrementing k, the CPU 51 determines whether k is the final number (step S28). If k is not the final number (step S28: NO), the CPU 51 returns the process to step S22. When k is the final number (step S28: YES), the CPU 51 corrects the position of the intersection as described above (see step S29, equations (1) to (4), FIGS. 9 and 10).

  As described above, the CPU 51 searches for intersections around the command point (step S30), corrects the position of the command point (see step S31, FIG. 11A and FIG. 11B), and returns to the machining path setting process (FIG. 5).

In the machine tool 100 and the control device 50 according to the first embodiment, the evaluation section D ^d intersecting the machining path is set, the position of the evaluation section D ^d and the intersection S _i ^d of the machining path is corrected, and the correction is made. Based on the position of the intersecting point S _i ^d, the position of the command point P _k in the direction intersecting the machining path is corrected. Even in the direction intersecting the machining path, the position of the command point P _k can be corrected, so that a smooth curved surface can be formed on the workpiece. In addition, the number of command points P _k existing between two adjacent evaluation sections is equal to or less than the threshold value. Thus the number of evaluation section D ^d to the number of command points P _k becomes too small, the precision of the position correction with respect to the command point P _k can be prevented from decreasing.

Whether the number M _d of command points P _k existing between two adjacent evaluation sections D ^d -D ^{d + 1} exceeds the threshold value T after setting the evaluation section D ^d at a predetermined interval. Determine. When the number M _d of command points P _k exceeds the threshold value T, a new evaluation section D ^new is added between two adjacent evaluation sections D ^d -D ^{d + 1} .

In addition, a new evaluation section D ^new is added at the center between two adjacent evaluation sections D ^d -D ^{d + 1} . When the evaluation cross section to be added is added in the vicinity of the existing evaluation cross section, the number M _d of the command points P _k is likely to exceed the threshold T, and further evaluation cross sections must be added. When a new evaluation section D ^new is added at the center between the evaluation sections D ^d -D ^{d + 1} , the number M _d of command points P ^k is less likely to exceed the threshold T, and additional evaluation sections are added. You do n’t have to. Therefore, the number of evaluation cross sections is prevented from being increased more than necessary.

(Embodiment 2)
Hereinafter, the present invention will be described with reference to the drawings showing a machine tool according to a second embodiment. Of the configurations according to the second embodiment, configurations similar to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 13 is a plan view schematically showing a machining path and an evaluation cross section for a workpiece. Arrows machining path, a dotted line indicates the evaluation section D ^d. The control device 50 sets the evaluation section D ^d for the workpiece. For example, as shown in FIG. 13, when the main shaft 5 a moves in a spiral shape, the processing path is a path along the spiral direction. As shown in FIG. 13, the control device 50 sets a plurality of evaluation sections D ^d along a direction substantially orthogonal to the machining path. The plurality of evaluation sections are arranged in the circumferential direction of the machining path. The operator instructs in advance that the direction of the machining path is the circumferential direction.

  The control device 50 executes a machining path setting process. FIG. 14 is a flowchart for explaining the machining path setting process by the control device 50.

  The CPU 51 of the control device 50 stands by until a start signal is input (step S41: NO). When the start signal is input (step S41: YES), the CPU 51 executes the outermost / innermost periphery calculation process (step S42), and executes the evaluation cross-section setting process (step S43).

  The CPU 51 executes an evaluation section addition process (step S44), executes a command point position correction process (step S45), and ends the machining path setting process. Details of the outermost / innermost circumference calculation process and the evaluation cross-section addition process will be described later.

  The outermost / innermost circumference calculation process (step S42) will be described. 15 is a flowchart for explaining the outermost / innermost circumference calculation processing, FIG. 16 is a schematic diagram schematically showing the machining path of the spindle 5a moving from the outer periphery side to the inner periphery side in a spiral shape, and FIG. It is a schematic diagram which shows schematically the processing path of the main axis | shaft 5a which moves to the outer peripheral side from an inner peripheral side in a shape.

The CPU 51 sequentially identifies identifiers (numbers) for a plurality of command points P _{k from} a command point (start point command point) P ₁ located at the start point of the machining path to a command point (end point command point) P _N located at the end point of the machining path. Is set (step S51).

The CPU 51 calculates the line segment P _a P _{a + 1} that is closest to the start point command point P ₁ (step S52), and calculates the line segment P _b P _{b + 1} that is closest to the end point command point P _N (step S53). .

CPU51 sets the machining path between the start command point P ₁ and the command point P _a to the route A (step S54), the machining path between the endpoints command point P _N and the command point P _b on the path B Set (step S55).

As shown in FIG. 7, when the main shaft 5a moves from the outer peripheral side to the inner peripheral side, the path A is positioned on the outermost side and the path B is positioned on the innermost side. As shown in FIG. 8, when the main shaft 5a moves from the inner circumference side to the outer circumference side, the path A is located on the innermost side and the path B is located on the outermost side. The nearest line segment P _a P _{a + 1} is calculated by calculating the shortest distance from the start point command point P1 to each of the line segments P ₂ P ₃ , P ₃ P ₄ ,... The line segment of the minimum distance is calculated. The same applies to the calculation of the nearest line segment P _b P _{b + 1} . Each of the path A and the path B has a substantially circular shape. The annular shape includes a spiral shape as shown in FIG.

CPU51 has the minimum value A _{x_min} and the maximum value A _{X_max} the X direction of the path A, and calculates the minimum value A _{Y_min} and the maximum value A _{Y_max} the Y direction (step S56).

CPU51 is the minimum value B _{x_min} and the maximum value B _{X_max} in the X direction of the path B, and calculating the minimum value B _{Y_min} and the maximum value B _{Y_max} the Y direction (step S57).

The CPU 51 determines whether or not A _{X_min} <B _{X_min} <B _{X_max} <A _{X_max} and A _{Y_min} <B _{Y_min} <B _{Y_max} <A _{Y_max} (step S58). When A _{X_min} <B _{X_min} <B _{X_max} <A _{X_max} and A _{Y_min} <B _{Y_min} <B _{Y_max} <A _{Y_max} (step S58: YES), the CPU 51 determines the route A as the outermost peripheral route. Then, the route B is determined as the innermost circumferential route located on the innermost side (step S59, see FIG. 16), the process returns to the machining route setting process and proceeds to the evaluation section setting process (step S43) (see FIG. 14).

If A _{X_min} <B _{X_min} <B _{X_max} <A _{X_max} and A _{Y_min} <B _{Y_min} <B _{Y_max} <A _{Y_max} (step S58: NO), the CPU 51 determines that B _{X_min} <A _{X_min} <A _{X_max} <B _{X_max} and B _{Y_min} < It is determined whether A _{Y_min} <A _{Y_max} <B _{Y_max} (step S60).

When B _{X_min} <A _{X_min} <A _{X_max} <B _{X_max} and B _{Y_min} <A _{Y_min} <A _{Y_max} <B _{Y_max} (step S60: YES), the CPU 51 determines the route A as the innermost circumferential route. Then, the route B is determined to be the outermost peripheral route located on the outermost side (step S61, see FIG. 17), and the process returns to the machining route setting process and proceeds to the evaluation section setting process (step S43) (see FIG. 14).

If B _{X_min} <A _{X_min} <A _{X_max} <B _{X_max} and B _{Y_min} <A _{Y_min} <A _{Y_max} <B _{Y_max} (step S60: NO), the CPU 51 notifies an error (step S62) and ends the process. For example, the display unit 8 displays that an error has occurred in the outermost / innermost circumference calculation process.

After the error notification, when the operator adjusts or changes the data such as setting the command value P _k again and inputs the start signal to the control device 50 again, the CPU 51 calculates the outermost / innermost circumference. You may comprise so that a process may be performed again.

  Next, the evaluation section setting process (step S43) will be described. FIG. 18 is a flowchart for explaining the evaluation cross-section setting process, and FIG. 19 is a schematic diagram for explaining the evaluation cross-section setting process.

The CPU 51 sets a plurality of first reference points O _m (m is a natural number) spaced equidistantly on the outermost circumference path (step S71), and sets a plurality of second reference points L _m on the innermost circumference path. (See step S72, FIG. 19).

The CPU 51 sets, as the second reference point L _m , a point that is on the innermost peripheral path and is closest to the first reference point O _m (step S72). The CPU 51 calculates and sets the evaluation cross section D ^d based on the first reference point O _m and the second reference point L _m (step S73). As shown in FIG. 19, CPU 51, as the first reference point O _m and the second reference point L _m is located on the evaluation section D ^d, and calculates the evaluation section D ^d, sets. The CPU 51 returns to the machining path setting process, and proceeds to the evaluation section addition process (step S44) and the command point position correction process (step S45) (see FIG. 14). The first reference points O _m are set at regular intervals in order from the start point command point P ₁ . The setting of the second reference point will be described later. The calculation of the evaluation section D ^d is a plane perpendicular to the XY plane, and a plane including the first reference point O _m and the second reference point L _m is calculated.

Since the second reference point L _m is located closest to the first reference point O _m , the evaluation cross section D ^d is substantially perpendicular to the innermost circumference path and the outermost circumference path.

In the evaluation cross section addition process (step S44), as in the evaluation cross section addition process (see FIG. 6) in the first embodiment, the CPU 51 determines that the command score M _d between the evaluation cross sections D ^d -D ^{d + 1} is _equal to the threshold T. It is determined whether or not it is exceeded. If the command number M _d exceeds the threshold T, evaluation section D ^d -D ^d + ¹ of adding new evaluation section D ^{new new} centrally between, all the evaluation section D ^d -D ^d + ¹ between On the other hand, after executing the above addition process, the section number d is reassigned (see FIG. 19).

  Since the evaluation cross section addition process (step S44) is the same as the evaluation cross section addition process (see FIG. 6) in the first embodiment, detailed description thereof is omitted.

FIG. 20 is a schematic diagram schematically showing the command point P _k , the evaluation section D ^d, and the intersection S _i ^{d of the} machining path. After execution of the evaluation section addition process (step S44), the CPU 51 executes a command point position correction process (step S45) as in the first embodiment.

  Since the command point position correction process (step S45) is the same as the command point position correction process (see FIG. 12) in the first embodiment, the description thereof is omitted.

  Even in the machine tool 100 and the control device 50 according to the second embodiment, the same operations and effects as those of the first embodiment are obtained.

(Embodiment 3)
Hereinafter, the present invention will be described based on the drawings showing a machine tool 100 according to a third embodiment. In the third embodiment, similarly to the second embodiment, the main shaft 5a moves in a spiral shape, and the machining path becomes a path along the spiral direction. Of the configurations according to the third embodiment, configurations similar to those of the first or second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The control device 50 executes a machining path setting process. FIG. 21 is a flowchart for explaining the machining path setting process by the control device 50. The CPU 51 of the control device 50 stands by until a start signal is input (step S81: NO).

  When the start signal is input (step S81: YES), the CPU 51 executes the outermost / innermost circumference calculation process (step S82), executes the second evaluation cross-section setting process (step S83), and instructs A point position correction process is executed (step S84), and the machining path setting process is terminated.

  The outermost / innermost circumference calculation process (step S82) is the same as the outermost / innermost circumference calculation process according to the second embodiment, and a description thereof will be omitted (see FIG. 15). After executing the outermost / innermost circumference calculation process, the CPU 51 executes a second evaluation cross-section setting process.

  The second evaluation section setting process will be described. FIG. 22 is a flowchart for explaining the second evaluation cross-section setting process, and FIG. 23 is a schematic diagram for explaining the second evaluation cross-section setting process.

The CPU 51 sets the command points P _{1 to} P _Z in order from the end of the outermost periphery path for the plurality of command points P _{k on} the outermost periphery path (see step S91). As shown in FIG. 16, when the route A is the outermost periphery route, P _{1 to} P _Z are set in order from the command point P ₁ located at the end of the route A. As shown in FIG. 17, when the route B is the outermost periphery route, P _{1 to} P _Z are set in order from the command point P _N located at the end of the route B.

  The CPU 51 sets 1 for each of the variables c and m (step S92). As described above, the storage unit 52 stores the variables c and m in advance.

CPU51 sets a first reference point O _m between the P _c and P _{c + 1} two command points adjacent (step S93). The storage unit 52 stores the set first reference point O _m . The CPU 51 adds the threshold value T2 to the variable c (step S94), and reads the command point _Pc after the addition of the threshold value T2 (step S95). The storage unit 52 stores the read command point P _c .

The CPU 51 increments the variable m by one (step S96), and determines whether or not the variable c is larger than Z (step S97). When the variable c is larger than Z, P _c is located inside the outermost circumference path, and when the variable c is not larger than Z, P _c is located on the outermost circumference path.

When the variable c is not larger than Z (step S97: NO), the CPU 51 returns the process to step S93. When the variable c is larger than Z (step S97: YES), the CPU 51 is on the innermost circumference path and stores each first reference point O _m (m = 1, 2, 3,...) Stored in the storage unit 52. ..) Is set to the second reference point L _m (m = 1, 2, 3,...) (See step S98, see FIG. 23).

The CPU 51 calculates and sets the evaluation cross section D ^d based on the first reference point O _m and the second reference point L _m (step S99). As shown in FIG. 23, CPU 51, as the first reference point O _m and the second reference point L _m is located on the evaluation section D ^d, and calculates the evaluation section D ^d, sets.

The second evaluation section setting process will be specifically described. The threshold T2 is set to 10. The CPU 51 sets command points P _{1 to} P _Z (step S91). Here, the command point P ₁ is a first command point, and the command point P ₂ is a second command point. At this time, the CPU 51 also sets a command point P ₁₁ (third command point) 10 points ahead from the command point P ₁ and a command point P ₁₂ (fourth command point) adjacent to the command point P ₁₁ .

The CPU 51 sets the first reference point O ₁ between the command point P ₁ and the command point P ₂ and sets the first reference point O ₂ between the command point P ₁₁ and the command point P ₁₂ (step) S93-S95). The CPU 51 repeats these processes for the entire outermost path (step 96, S97). That is, the same process is repeated with the third reference point as the first reference point and the fourth reference point as the second reference point.

The CPU 51 sets each point located closest to each first reference point O _m (m = 1, 2, 3,...) On the innermost circumference path to the second reference point L _m (m = 1, 2, 3,...) (Step S 98), and the evaluation cross section D ^d is set so as to include the first reference point O _m and the second reference point L _m (step S 99).

  The CPU 51 returns to the machining path setting process and proceeds to the command point position correction process (step S84) (see FIG. 21). Since the command point position correction process (step S84) is the same as the command point position correction process (see FIG. 12) of the first or second embodiment, the description thereof is omitted.

  In the machine tool 100 and the control device 50 according to the third embodiment, between the first command point and the second command point adjacent to the first command point, and between the third command point and the third command point. An evaluation cross section is set between adjacent fourth command points. The first command point and the third command point are separated by a distance corresponding to the threshold value T2. Therefore, it is possible to prevent the number of evaluation sections from becoming excessively small or excessively, and to prevent a decrease in accuracy of position correction with respect to the command point and an increase in calculation amount.

  In addition, an evaluation cross section is set at the center between the first command point and the second command point and at the center between the third command point and the fourth command point, respectively, and an appropriate number of evaluation cross sections are set.

  In the third embodiment, the machining path has a spiral shape. However, as in the first embodiment, the main shaft 5a largely reciprocates along the X or Y direction, and the machining path moves in the X or Y direction. Even in the case of the route along the path, the configuration according to the third embodiment can be applied. In this case, the configuration according to the third embodiment may be applied not to the outermost peripheral path but to, for example, any one-way path located at the first, last, or center, as compared to the case where the processing path has a spiral shape. However, the amount of calculation is reduced.

FIG. 24 is a plan view schematically showing a machining path and an evaluation cross section for a workpiece in a modified example. As shown in FIG. 24, when the machining path has a spiral shape, the control device 50 sets the center of the spiral and the angle around the center, and sets a plurality of evaluation cross sections radially with respect to the center of the spiral. When a command point existing between two adjacent evaluation sections exceeds a predetermined threshold value, a new evaluation section D ^new is added between the two evaluation sections.

5a Spindle 50 Controller 51 CPU
52 storage unit 53 RAM
100 machine tools

Claims (8)

In a control device that sets a machining path based on a plurality of command points that indicate the position of the spindle, and controls the movement of the spindle based on the machining path.
A setting unit configured to set a plurality of evaluation cross sections intersecting the machining path so that the number of the command points existing between two adjacent evaluation cross sections is equal to or less than a threshold;
A calculation unit for calculating an intersection of the evaluation section and the machining path set by the setting unit;
An intersection position correction unit for correcting the position of the intersection calculated by the calculation unit;
And a command point position correcting unit that corrects a position of the command point in a direction intersecting the machining path based on the intersection corrected by the intersection position correcting unit. The setting unit
A determination unit that determines whether or not the number of the command points existing between two adjacent evaluation cross sections exceeds a threshold value after setting the evaluation cross sections at predetermined intervals in the machining path; ,
When the determination unit determines that the number of the command points existing between two adjacent evaluation cross sections exceeds a threshold value, an additional evaluation cross section is added between the two evaluation cross sections. The control device according to claim 1, further comprising: an additional setting unit. The control apparatus according to claim 2, wherein the additional setting unit adds an evaluation cross section at a center between the two evaluation cross sections. The plurality of command points include a first command point and a second command point located next to the first command point,
The setting unit
A first setting unit for setting one evaluation section between the first command point and the second command point;
A second setting unit that sets a third command point that is separated from the first command point by a distance corresponding to the threshold value, and a fourth command point that is located next to the third command point;
The control device according to claim 1, further comprising: a third setting unit that sets the other evaluation section between the third command point and the fourth command point set by the second setting unit. . The first setting unit sets the one evaluation cross section at the center between the first command point and the second command point,
5. The control device according to claim 4, wherein the third setting unit sets the other evaluation section at a center between the third command point and the fourth command point. A control device according to any one of claims 1 to 5;
A machine tool comprising the spindle. In a control method for setting a machining path based on a plurality of command points that indicate the position of the spindle, and controlling the movement of the spindle based on the machining path,
A plurality of evaluation cross sections intersecting the machining path is set so that the number of the command points existing between two adjacent evaluation cross sections is equal to or less than a threshold value,
Calculate the intersection of the set evaluation cross section and the machining path,
Correct the position of the intersection calculated by the calculation unit,
A control method comprising correcting a position of the command point in a direction intersecting the machining path based on the corrected intersection. In a computer program that can be executed by a control device that sets a machining path based on a plurality of command points that indicate the position of the spindle according to the machining program and controls the movement of the spindle based on the machining path.
The control device;
A setting unit that sets a plurality of evaluation cross sections intersecting the machining path so that the number of the command points existing between two adjacent evaluation cross sections is equal to or less than a threshold value,
A calculation unit for calculating an intersection of the evaluation section and the machining path set by the setting unit;
An intersection position correcting unit that corrects the position of the intersection calculated by the calculating unit, and a command point position that corrects the position of the command point in the direction intersecting the machining path based on the intersection corrected by the intersection position correcting unit A computer program that functions as a correction unit.

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