Motion control device, motion control method, and motion control program

Abstract

This operation control device is used for mounting an object on a target having a cylindrical peripheral surface from the axial direction of the peripheral surface, and comprises a processing circuit. The processing circuit is configured to: execute a center calculation process for calculating final center coordinates, which indicate the coordinates of the center of the peripheral surface as seen from the axial direction; control a robot holding the object and position the object relative to the final center coordinates; and control the robot holding the object and mount the object on the target.

Description

[Technical field]

[0001] The present disclosure relates to a motion control device, a motion control method, and a motion control program for attaching an object to a target by a robot. [Background technology]

[0002] Patent Document 1 discloses a cutting tool changing device that automates the task of changing a cutting tool attached to a holder in a machine tool. In the cutting tool changing device, a conveying device removes a cutting tool from a holder and attaches a different cutting tool to the holder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-37553 Summary of the Invention [Problem to be solved by the invention]

[0004] When a robot is used to fit a tool such as a cutting tool into a holder, a human being uses a teaching pendant to teach the robot the trajectory of the movement. Since the accuracy of the robot's movement depends on the skill of the human teacher, the accuracy of the tool fitting operation may be poor.

[0005] Another possible configuration is to provide a force sensor in the robot and guide the tool to the holder while correcting the tool position according to the detection signal of the force sensor. In that case, the tool slides on the surface of the holder because the force sensor detects that the tool has interfered with the holder and then corrects the tool position, which may cause scratches on the holder and tool. In addition, systems using force sensors tend to be expensive.

[0006] Such a tool fitting operation is not limited to a cutting tool replacement operation, but may occur in various operations. Also, the operation is not limited to a tool fitting operation, but may occur in an operation of attaching some object to some target.

[0007] Therefore, an object of the present disclosure is to enable a robot to perform a highly accurate mounting operation while avoiding high costs and the occurrence of scratches. [Means for solving the problem]

[0008] A motion control device according to an aspect of the present disclosure is a motion control device for attaching an object to a target having a cylindrical peripheral surface from an axial direction of the peripheral surface, the motion control device including a processing circuit. The processing circuit is configured to execute a center calculation process for calculating final center coordinates indicating center coordinates of the peripheral surface as viewed from the axial direction, control a robot holding the object to align the object with the final center coordinates, and control the robot holding the object to attach the object to the target. Executing the center calculation process includes controlling the robot holding a sensing device to detect position coordinates of at least four detection points at different positions in the circumferential direction on the peripheral surface as a detection point group, selecting a selection point group from the detection point group in different combinations, the selection point group being less in number than the detection point group and including position coordinates of at least three points, and calculating the arc center coordinates of each of the selection point groups as tentative center coordinates, and calculating the final center coordinates based on the tentative center coordinates.

[0009] A motion control method according to one aspect of the present disclosure is a motion control method for attaching an object to a target having a cylindrical peripheral surface from an axial direction of the peripheral surface, the motion control method comprising: executing a center calculation process for calculating final center coordinates indicating center coordinates of the peripheral surface as viewed from the axial direction, controlling the robot holding the object to align the object with respect to the final center coordinates, and controlling the robot holding the object to attach the object to the target. Executing the center calculation process includes controlling the robot holding a sensing device to detect position coordinates of at least four detection points at different positions in a circumferential direction on the peripheral surface as a detection point group, selecting a plurality of selected point groups from the detection point group in different combinations, the selection point group being less in number than the detection point group and including position coordinates of at least three points, calculating arc center coordinates of each of the plurality of selected point groups as tentative center coordinates, and calculating the final center coordinates based on the plurality of tentative center coordinates.

[0010] An operation control program according to an embodiment of the present disclosure causes at least one processor to execute the operation control method. The program may be stored in a computer-readable storage medium. The storage medium is a non-transitory, tangible medium. The storage medium may be built into or externally attached to a computer (e.g., a mobile information terminal, a personal computer, a server, etc.). The storage medium may include RAM, ROM, EEPROM, storage, etc., and may be, for example, a hard disk, a flash memory, an optical disk, etc. The program stored in the storage medium may be executed in a computer to which the storage medium is directly connected, or may be executed in a computer connected to the storage medium via a network (e.g., the Internet). Effect of the Invention

[0011] According to one aspect of the present disclosure, the central coordinates of the peripheral surface of the target are calculated with high accuracy by the robot, so that the robot can perform a highly accurate mounting operation. Also, the robot can mount an object on the target without using a force sensor. Therefore, the robot can perform a highly accurate mounting operation while avoiding high costs and damage. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view illustrating a mounting operation of a robot controlled by a motion control device according to an embodiment. [Diagram 2] FIG. 2 is a block diagram of the operation control device etc. of FIG. [Diagram 3] FIG. 3 is an enlarged perspective view of a cylindrical hole of the holder of FIG. [Figure 4] FIG. 4 is a flowchart illustrating the process of the operation control device of FIG. [Diagram 5] FIG. 5 is a flowchart illustrating the center calculation process of FIG. [Figure 6] FIG. 6 is a perspective view for explaining teaching of the robot controlled by the motion control device of FIG. [Figure 7] FIG. 7 is a plan view illustrating the detection point group. [Figure 8] FIG. 8 is a schematic diagram for explaining the provisional center coordinates of the selected point group. [Figure 9] FIG. 9 is a schematic diagram for explaining intermediate processing of the provisional center coordinates in FIG. [Figure 10] FIG. 10 is a schematic diagram for explaining the final processing of the provisional center coordinates in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment will be described with reference to the drawings.

[0014] Fig. 1 is a perspective view illustrating the mounting operation of a robot 4 controlled by a motion control device 5 according to an embodiment. As shown in Fig. 1, the motion control system 1 includes a robot 4 installed on an installation surface G, and a motion control device 5 that controls the robot 4. As an example, a tool presetter 2 is disposed in the working area of ​​the robot 4. Note that the device is not limited to the tool presetter 2, and may be another device related to the mounting operation by the robot 4.

[0015] The tool presetter 2 includes a base 11 and a holder holding table 12 supported by the base 11. The tool presetter 2 is a known device for measuring the shape of the cutting edge of a machining tool 7 of a machine tool, the dimensions of the cutting edge, the runout of the machining tool 7 (the amount of swing when the machining tool 7 rotates), and the protrusion amount of the machining tool 7, etc., using a camera or the like. A holder 3 having a cylindrical hole H is attached to the holder holding table 12. The holder 3 has a cylindrical inner surface Ha for defining the cylindrical hole H. The axial direction V of the cylindrical hole H of the holder 3 coincides with the Z direction perpendicular to the reference plane (XY plane) of the tool presetter 2.

[0016] In the tool presetter 2, a machining tool 7 having a cylindrical outer peripheral surface is mounted in a cylindrical hole H of a holder 3 by a robot 4. The cutting edge of the machining tool 7 held in the holder 3 is exposed upward from the holder 3. The tool presetter 2 measures the shape and dimensions of the cutting edge of the machining tool 7 held in the holder 3. After the measurement, the holder 3 holding the machining tool 7 is removed from the holder holding table 12, and the holder 3 holding the machining tool 7 is attached to a machine tool. For example, in the tool presetter 2, a fitting operation is performed by the robot 4 to insert the machining tool 7 into the cylindrical hole H of the holder 3. The holder 3 is an example of a target. The machining tool 7 is an example of an object to be attached to the target.

[0017] The robot 4 is, for example, an articulated robot. The robot 4 includes a base 21, a plurality of arms 22, a plurality of joints 23, and a plurality of actuators 24. The base 21 is installed on an installation surface G. The joints 23 rotatably connect adjacent arms 22 to each other. The actuators 24 drive the arms 22 to rotate the joints 23. A hand 26 is attached to the arm 22 on the tip side of the robot 4. The hand 26 holds the processing tool 7 with the cutting edge facing upward.

[0018] Between the arm 22 at the tip side of the robot 4 and the hand 26, for example, a compliance unit 25 and a robot hand changer may be interposed. The compliance unit 25 is a device that corrects misalignment of an object or a target when attaching the object to a target. The robot hand changer is a component that enables a robot hand suitable for a task to be attached to the robot arm. Each actuator 24 of the robot 4 is controlled by the motion control device 5.

[0019] FIG. 2 is a block diagram of the motion control device 5 and the like in FIG. 1. As shown in FIG. 2, the motion control device 5 is connected to the robot 4 so as to be able to control the actuator 24. A teaching pendant 8 is communicatively connected to the motion control device 5. The motion control device 5 includes a processor 31, a system memory 32, a storage memory 33, and an interface 34. The processor 31 may include a CPU (Central Processing Unit). The system memory 32 may include a RAM. The storage memory 33 may include a ROM. The storage memory 33 may include a hard disk and / or a flash memory. The storage memory 33 stores a motion control program 35. The configuration in which the processor 31 executes the motion control program 35 read into the system memory 32 is an example of a processing circuit. A part or all of the motion control program 35 may be executed by another controller or a server instead of the processor 31.

[0020] FIG. 3 is an enlarged perspective view of the cylindrical hole H of the holder 3 in FIG. 1. As shown in FIG. 3, if the motion control device 5 can grasp the coordinates (mounting center coordinates) of the center Cf1 of the cylindrical hole H as viewed from the axial direction V and the axis AX of the cylindrical hole H, the machining tool 7 (see FIG. 1) can be mounted in the cylindrical hole H with high accuracy. The first circle B1 is a circle on the inner circumferential surface Ha at the first axial position D1 in the axial direction V of the cylindrical hole H. The first circle center Cf1 is the center of the first circle B1. The second circle B2 is a circle on the inner circumferential surface Ha at the second axial position D2 in the axial direction V of the cylindrical hole H. The circle of the second circle B2 on the inner circumferential surface Ha at the second axial position D2 is located deeper than the circle of the first circle B1 on the inner circumferential surface Ha at the first axial position D1. The second circle center Cf2 is the center of the second circle B2.

[0021] Fig. 4 is a flowchart explaining the processing of the motion control device 5 in Fig. 2. Fig. 5 is a flowchart explaining the center calculation processing in Fig. 4. Below, an explanation will be given along the flow of the flowcharts in Figs. 4 and 5 with appropriate reference to Figs. 1, and 6 to 10. In the following explanation, the processing contents of the motion control device 5 refer to the processing contents of the processor 31 that executes the motion control program 35 read into the system memory 32.

[0022] FIG. 6 is a perspective view for explaining teaching of the robot 3 controlled by the motion control device 5 of FIG. 1. As shown in FIG. 6, first, a touch probe 6 is held as a sensing device in the hand 26 of the robot 4. The TCP (Tool Center Point) of the touch probe 6 is taught to the motion control device 5 by operating the teaching pendant 8. The motion control device 5 makes the inclination of the reference plane (xy plane) for control of the robot 4 correspond to the inclination of the target reference plane SF (XY plane) (step S1). The reference plane for control of the robot 4 and the target reference plane SF may be planes other than the xy plane and the XY plane, respectively.

[0023] Specifically, the motion control device 5 controls the robot 4 to have the touch probe 6 touch three different points on the target reference surface SF perpendicular to the axial direction V of the cylindrical hole H. It is desirable to have a larger number of points touched by the touch probe 6, since it is easier to accurately calculate the target reference surface SF as a surface perpendicular to the axial direction V of the cylindrical hole H. The target reference surface SF may be, for example, the upper surface of the holder holding table 12, but may be another surface (for example, the upper surface of the tool presetter 2, the upper surface of the holder 3, the installation surface G, etc.) as long as it is known to be perpendicular to the axial direction V of the cylindrical hole H. The motion control device 5 detects the position coordinates of the three different points detected by the touch probe 6, and calculates the inclination of the target reference surface SF from the position coordinates of the three points. Then, the motion control device 5 makes the inclination of the reference surface in the control of the robot 4 correspond to the inclination of the target reference surface SF. In this case, the inclination of the reference surface of the robot 4 may be made to coincide with the inclination of the target reference surface SF, or may be determined to have a predetermined relative angle relationship.

[0024] Next, the operator operates the teaching pendant 8 to control the robot 4 holding the touch probe 6, thereby teaching the motion control device 5 the motion of the robot 4 inserting the touch probe 6 into the cylindrical hole H of the holder 3 and touching the touch probe 6 at four points in the circumferential direction on the inner peripheral surface Ha of the cylindrical hole H (step S2). The operator may also teach the motion of the touch probe 6 touching four points on the outer surface of the cylindrical hole H of the holder 3 (step S2). The positions and number of points to be touched by the touch probe 6 are determined taking into consideration the positional relationship between the holder 3 and the machining tool 7 and the accuracy of the mounting work. It is desirable that the points to be touched by the touch probe 6 are many and equally spaced in the circumferential direction. This teaching work is commonly used for the mounting work on the holder 3, and it is sufficient to perform it once, but it may be performed multiple times.

[0025] The teaching method is not limited to the above-mentioned method of holding the touch probe 6. For example, the teaching may be performed by reproducing the environment of the mounting work on simulation software and teaching the movement trajectory, without using the touch probe 6. The teaching may be performed by a person directly operating the robot and teaching the movement trajectory, without using the teaching pendant 8.

[0026] Next, the motion control device 5 executes a center calculation process for the first axial position D1 of the cylindrical hole H of the holder 3 (step S3). In the center calculation process, mounting center coordinates indicating the center coordinates of the inner circumferential surface Ha viewed from the axial direction V of the cylindrical hole H are calculated. In the center calculation process, a subroutine shown in Fig. 5 is executed. The contents of the center calculation process will be described below.

[0027] As shown in FIG. 7, the motion control device 5 detects the position coordinates of four different detection points P1 to P4 on the inner peripheral surface Ha of the cylindrical hole H as a group of detection points according to the instruction (step S31 in FIG. 5). The detection points P1 to P4 are at different positions in the circumferential direction of the first circle B1 (see FIG. 3). The number of the detection points P1 to P4 is an even number. The detection points P1 to P4 are arranged on the inner peripheral surface Ha as viewed from the axial direction V. It is desirable that the detection points P1 to P4 are arranged at equal intervals in the circumferential direction on the first circle B1. For example, the detection points P1 to P4 are arranged at least one in each region obtained by equally dividing the inner peripheral surface Ha into four regions in the circumferential direction as viewed from the axial direction V.

[0028] 8, the motion control device 5 selects four selected point groups Q1-4, each including position coordinates of three points in a different combination, from the detected point groups P1-P4 (step S32 in FIG. 5). Next, the motion control device 5 calculates the coordinates of the arc center points (arc center coordinates) of each of the four selected point groups Q1-4 as the coordinates of provisional center points R1-R4 (first provisional center coordinates) (step S33 in FIG. 5).

[0029] Specifically, an arc passing through the first selected point group Q1 (P1, P2, P3) is identified, and its arc center point is obtained, and the arc center point is set as the provisional center point R1. Similarly, an arc passing through the second selected point group Q2 (P2, P3, P4) is identified, and its arc center point is obtained, and the arc center point is set as the provisional center point R2. Similarly, an arc passing through the third selected point group Q3 (P1, P3, P4) is identified, and its arc center point is obtained, and the arc center point is set as the provisional center point R3. Similarly, an arc passing through the fourth selected point group Q4 (P1, P2, P4) is identified, and its arc center point is obtained, and the arc center point is set as the provisional center point R4.

[0030] Next, the operation control device 5 averages the coordinates of the four temporary center points R1 to R4 to calculate the final center coordinates as the mounting center coordinates of the cylindrical hole H (the coordinates of the first circle center Cf1 in FIG. 3) (see step S34 in FIG. 5). Specifically, as shown in FIG. 9, the operation control device 5 calculates, in the first stage, coordinates (second temporary center coordinates) obtained by averaging the coordinates of the temporary center points of two pairs of diagonally (opposite) selected point groups. That is, the operation control device 5 calculates, as the coordinates of the temporary center point R5, the point coordinates obtained by averaging the coordinates of the temporary center point R1 of the first selected point group Q1 (P1, P2, P3) and the coordinates of the temporary center point R3 of the third selected point group Q3 (P1, P3, P4). Similarly, the coordinates of the provisional center point R2 of the second selected point group Q2 (P2, P3, P4) and the coordinates of the provisional center point R4 of the fourth selected point group Q4 (P1, P2, P4) are averaged to calculate the coordinates of the provisional center point R6. Note that, as a first step, the motion control device 5 may calculate the average value of the coordinates of the provisional center points of two pairs of selected point groups that are not in a diagonal relationship (opposite relationship).

[0031] Then, as shown in FIG. 10, in the second stage, the operation control device 5 calculates the coordinates of the final center point R7 (final center coordinates) by averaging the coordinates of the temporary center points R5 and R6 (second temporary center coordinates). The calculated coordinates of the final center point R7 correspond to the mounting center coordinates of the cylindrical hole H (the coordinates of the first circle center Cf1 in FIG. 3). Note that the final center coordinates may be calculated by averaging the coordinates of the temporary center points R1 to R4 (first temporary center coordinates) all at once, without calculating the second temporary center coordinates. Also, instead of using the average value of the multiple temporary center coordinates, the median value of the multiple temporary center coordinates may be used, or other values ​​may be used instead.

[0032] Returning to Fig. 4, the motion control device 5 executes a center calculation process for the second axial position D2 of the cylindrical hole H of the holder 3 (step S4). This center calculation process is similar to steps S31 to S34 described above, so detailed description will be omitted. By the center calculation process for the second axial position D2, the coordinates of the second circle center Cf2 of the second circle B2 (see Fig. 3) at the second axial position D2 in the axial direction V of the inner circumferential surface Ha are calculated as the final center coordinates.

[0033] Next, the motion control device 5 calculates a straight line passing through the final center coordinates (coordinates of the first circle center Cf1) at the first axial position D1 calculated in step S3 and the final center coordinates (coordinates of the second circle center Cf2) at the second axial position D2 calculated in step S4 as the axis AX (see FIG. 3) of the cylindrical hole H (step S5). Note that steps S4 and S5 may be omitted. For example, when the axis AX is set in advance to be perpendicular to the upper surface of the target reference surface SF (e.g., the holder holding table 12) or when the direction in which the axis AX extends is known by other means, steps S4 and S5 may be omitted.

[0034] 1, the hand 26 of the robot 4 holds the processing tool 7 instead of the touch probe 6 (step S6). Next, the motion control device 5 controls the robot 4 to align the axis of the processing tool 7 with the final center coordinates calculated in step S3 (step S7). In addition, the motion control device 5 may control the robot 4 to align the attitude of the processing tool 7 with the attitude of the cylindrical hole H so that the axis of the processing tool 7 coincides with the axis AX calculated in step S5 (step S7).

[0035] As a method for aligning the central axis of the processing tool 7 with the final central coordinates, for example, the TCP (Tool Center Point) of the touch probe 6 is taught to the motion control device 5. The touch probe 6 is designed so that the TCP of the touch probe 6 corresponds to the TCP of an object (e.g., the processing tool 7). Then, the motion control device 5 controls the touch probe 6 to teach the TCP of the touch probe 6, whereby information on the reference coordinates and orientation of the object held by the robot 4 is input to the motion control device 5. By teaching the reference coordinates and orientation of the object as the central axis of the object, it is possible to align the central axis of the object (e.g., the processing tool 7) with the central axis of the target (e.g., the holder 3).

[0036] Finally, the motion control device 5 controls the robot 4 to move the processing tool 7 along the final center coordinates calculated in step S3 or the axis AX (see FIG. 3) calculated in step S5, and mounts the processing tool 7 in the cylindrical hole H of the holder 3 (step S8). When mounting another processing tool 7 on another holder 3, steps S1 and S2 may be omitted since they have already been completed, and steps S3 to S8 may be performed.

[0037] According to the configuration described above, the mounting center coordinates Cf1 (R7) indicating the center coordinates of the inner circumferential surface Ha of the holder 3 are calculated with high accuracy by using the robot 4. For example, the motion control device 5 can perform the task of fitting the processing tool 7 into the cylindrical hole H of the holder 3 with high accuracy. Also, the robot 4 can attach the processing tool 7 to the holder 3 without using a force sensor. Therefore, it is possible to realize the mounting task with high accuracy by the robot 4 while avoiding high costs and the occurrence of scratches. Also, it is possible to avoid damage to the sensor and erroneous detection (false recognition).

[0038] When the number of detection point groups P1 to P4 is an even number, different combinations of selection point groups Q1 to Q4 can be arranged diagonally with respect to the center of the circle of the inner circumferential surface Ha of the holder 3. Therefore, even if the circularity of the inner circumferential surface Ha is not high when viewed from the axial direction V, it is possible to improve the agreement between the actual center coordinates and the final center coordinates of the inner circumferential surface Ha of the holder 3 when viewed from the axial direction V.

[0039] When the detection points P1-P4 are disposed at equal intervals in the circumferential direction of the inner peripheral surface Ha as viewed from the axial direction V (for example, when the detection points are four points, at least one point is disposed in each of the four equal regions), different combinations of the selection points Q1-Q4 can be dispersed over a wide range in the circumferential direction of the inner peripheral surface Ha. Therefore, even if the circularity of the inner peripheral surface Ha of the holder 3 is not high as viewed from the axial direction V, it is possible to improve the agreement between the actual center coordinates and the final center coordinates of the inner peripheral surface Ha of the holder 3 as viewed from the axial direction V.

[0040] Furthermore, when priority is given to work time over work accuracy, the number of detection points P1 to P4 detected by the touch probe 6 can be reduced to four, thereby shortening the work time. The number of detection points may also be three.

[0041] When the axis line AX is calculated based on the first circle center Cf1 and the second circle center Cf2 and the machining tool 7 is moved along the axis line AX, the machining tool 7 can be smoothly attached to the cylindrical hole H. For example, the machining tool 7 can be smoothly fitted into the cylindrical hole H.

[0042] Since the inclination of the reference plane of the robot 4 corresponds to the inclination of the target reference plane, even if the posture of the cylindrical hole H of the holder 3 is misaligned with the installation posture of the robot 3, the robot 4 can be operated with high precision relative to the cylindrical hole H.

[0043] In the above-described embodiment, the inner peripheral surface Ha of the holder 3 on which the machining tool 7 is mounted is exemplified as being completely cylindrical, but the present invention is not limited to this and may be substantially cylindrical. For example, the inner peripheral surface Ha of the holder 3 may be a plurality of arcuate surfaces that partially constitute a cylinder. For example, the inner peripheral surface Ha of the holder 3 may be a pair of arcuate surfaces that face each other with a gap therebetween, or may be C-shaped when viewed from the axial direction.

[0044] In the above-described embodiment, mounting refers to attaching a target to an object. Fitting refers to the outer peripheral surface of an object approaching or abutting the inner peripheral surface of a target, or the inner peripheral surface of an object approaching or abutting the outer peripheral surface of a target. The relationship between the target and the object may be reversed. For example, an object having a cylindrical hole may be the object and a cylinder to be inserted into the cylindrical hole may be the target, and the center coordinates of the cylinder may be calculated based on a group of detection points on the outer peripheral surface of the cylinder. A shaft may be the target and a bearing fitted onto the shaft may be the object. Holding refers to making an object into a state in which it can be lifted.

[0045] In the above-described embodiment, one robot is controlled by one motion control device, but a configuration using a plurality of motion control devices or a plurality of robots may also be used.

[0046] Various calculation formulas can be used to calculate information such as position coordinates, provisional center coordinates, and final center coordinates on the target reference surface used in the motion control device, motion control method, and motion control program. For example, the calculations can be performed by substituting the acquired coordinates into a predetermined calculation formula and solving simultaneous equations. The calculations can also be performed using the least squares method. Such calculations can be performed, for example, by built-in or external circuits, or commands provided in the motion control device, robot, machine tool, equipment, etc. Then, the calculated information can be sent to the motion control device.

[0047] In this specification, concepts that define positional relationships, shapes, sizes, states, etc., such as "center," "coincident," "orthogonal," "straight line," "cylinder," "cylindrical," "equally spaced," etc., are concepts that include "substantially center," "substantially coincident," "substantially orthogonal," "substantially straight line," "substantially cylindrical," "substantially cylindrical," "substantially equally spaced," etc. Also, in this specification, "circumferential direction" and "axial direction" are concepts that include "substantially circumferential direction" and "substantially axial direction."

[0048] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general purpose processors, special purpose processors, integrated circuits, Application Specific Integrated Circuits (ASICs), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. Processors are considered processing circuits or circuits because they include transistors and other circuits. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. In the case where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or the processor. [Explanation of symbols]

[0049] 1. Motion Control System 3 Holder (target) 4. Robot 5. Motion control device 6 Touch probe (sensing device) 7 Processing Tools (Objects) 31 Processors 35 Motion Control Program D1 1st axial position D2 2nd axial position AX axis R7, Cf1 First circle center (final center coordinates, mounting center coordinates) Cf2 Second circle center (final center coordinates) H Cylindrical bore Ha Inner surface P1~P4 detection points R1~R6 Temporary center point SF target reference plane V axis direction

Claims

1. 1. A motion control device for attaching an object to a target having a cylindrical peripheral surface from an axial direction of the peripheral surface, comprising: A processing circuit is provided, the processing circuit comprising: executing a center calculation process for calculating final center coordinates indicating center coordinates of the circumferential surface as viewed from the axial direction; controlling a robot holding the object to align the object with respect to the final center coordinates; and controlling the robot holding the object to attach the object to the target. Executing the center calculation process includes: Controlling the robot holding the sensing device to detect position coordinates of at least four detection points at different positions in a circumferential direction on the peripheral surface as a detection point group; selecting a plurality of selected points from the detection point group in different combinations, the selected points being smaller in number than the detection point group and including position coordinates of at least three points; Calculating the coordinates of the arc center of each of the plurality of selected points as provisional center coordinates; and calculating the final center coordinate based on the plurality of temporary center coordinates.

2. The motion control device according to claim 1 , wherein the number of detection points is an even number.

3. The motion control device according to claim 1 , wherein the detection points are disposed at least one in each of four regions obtained by equally dividing the circumferential surface in the circumferential direction as viewed from the axial direction.

4. The motion control device according to claim 1 , wherein the detection points are arranged on the circumferential surface at equal intervals in the circumferential direction.

5. executing the center calculation process means executing the center calculation process with respect to the final center coordinates at a first axial position in the axial direction of the circumferential surface, The processing circuitry includes: executing the center calculation process for a final center coordinate at a second axial position in the axial direction of the peripheral surface; calculating an axis of the circumferential surface based on the final center coordinates at the first axial position and the final center coordinates at the second axial position, The motion control device of claim 1 or 2, wherein attaching the object to the target comprises moving the object along the axis.

6. The processing circuitry includes: Controlling the robot holding the sensing device to detect position coordinates of at least three points on a target reference plane, which is a reference plane perpendicular to the axial direction; Calculating a tilt of the target reference surface based on the position coordinates; Corresponding an inclination of the robot reference plane to an inclination of the target reference plane; The motion control device according to claim 1 or 2, further configured to:

7. 1. A motion control method for attaching an object to a target having a cylindrical peripheral surface from an axial direction of the peripheral surface, comprising: executing a center calculation process for calculating final center coordinates indicating center coordinates of the circumferential surface as viewed from the axial direction; controlling a robot holding the object to align the object with respect to the final center coordinates; controlling the robot holding the object to attach the object to the target; Executing the center calculation process includes: Controlling the robot holding the sensing device to detect position coordinates of at least four detection points at different positions in a circumferential direction on the peripheral surface as a detection point group; selecting a plurality of selected points from the detection point group in different combinations, the selected points being smaller in number than the detection point group and including position coordinates of at least three points; Calculating the coordinates of the arc center of each of the plurality of selected points as provisional center coordinates; and calculating the final center coordinates based on the plurality of temporary center coordinates.

8. A motion control program that causes at least one processor to execute the motion control method according to claim 7.

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