JPH08224623A - Robot work gripping control device - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] A work gripping motion control device that allows the relative position and relative posture of a robot hand with respect to a work placed on a work placing table to be arbitrarily changed. [Structure] At the time of teaching, the reference position (Xs
0, Ys0, θs0) The first reference serving as a work when the hand 41 grips the work 12 so that the hand 41 has a desired relative position and relative attitude with respect to the work 12 placed on the first work.
Position (Xs0, Ys0) and posture angle θs0 are measured by the measuring means 32.
And the second position (Xs1, Ys1) of the work when the hand holding the work is moved by the constant posture angle θT0, and is measured by the measuring means, and the placement position of the work with respect to the first position is measured. The deviations ΔXs1, ΔYs1, and Δθs1 are used as correction amounts for the hand position and attitude angle (ΔXT1, ΔYT1, and Δθ).
T1) is converted and calculated, and the position and posture angle of the hand are corrected by this correction amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling a robot so that the hand of the robot grips the work, and more particularly to a device for causing the robot to grip the work before carrying the work into a sheet metal machine such as a press. Regarding the device.

[0002]

2. Description of the Related Art Japanese Utility Model Publication No. 63-133831 discloses
Work pieces stacked in a pallet are once placed on a table, and then the work pieces placed on the table are photographed by a visual device.Then, the work pieces are taken out from the table, and the work pieces photographed above are displayed. A work transfer device is disclosed in which a work is transferred on a transfer bar of a transfer device with correction based on a posture and a work is always placed on the transfer bar at a fixed position and a fixed posture.

In this case, a chuck for clamping and unclamping a work is mounted on a slide shaft, and the slide shaft moves on a guide rail. Therefore, the degree of freedom of the chuck is restricted by the guide rail, and the movement in the direction perpendicular to the guide rail is significantly restricted.

[0004]

As described above, in the conventional work transfer device, the work can be placed on the transfer bar so that the work is always in a fixed position and in a fixed posture. Therefore, if the transfer bar always grips a certain part of the work, no problem will occur even if this kind of work transfer device is used.

However, in the press brake robot, the part for gripping the work and the gripping posture are completely different between the front bending work process and the lateral bending work process. In addition, there may be a case where it is necessary to change the gripping position and gripping position of the work depending on the type of work. However, in the above-described conventional work transfer device, since the chuck has a limited degree of freedom as described above, when the work on the table is clamped, the relative position of the chuck with respect to the work,
It is impossible, or even possible, to change the relative attitude arbitrarily. In addition, there is a limit to putting a work on the transfer bar with modification, and it is impossible or even possible to arbitrarily change the relative position and relative posture of the transfer bar with respect to the work. It's not easy.

As described above, in the conventional work transfer device, it is difficult to arbitrarily change the gripping position and gripping position of the work to a desired one.

The present invention has been made in view of these circumstances, and the relative position and relative posture of the robot hand with respect to the work placed on the work placement table can be easily changed to a desired work. An object of the present invention is to provide a gripping motion control device.

[0008]

Therefore, the present invention comprises a control means for controlling the position and posture of the robot hand so that the robot hand holds the work placed on the work placing table. In a work gripping operation control device of a robot, a measuring means for measuring a position and an attitude angle of a work placed on the work placing table is provided, and the control means uses the hand with the hand on the work placing table at the time of teaching. A first position and a posture angle that are the reference of the work when the work is gripped are measured by the measuring means, and a second of the work when the hand that grips the work is moved by a fixed posture angle. The position is measured by the measuring unit, and the first position and the second position, which are the reference of the work measured by the measuring unit, and the constant posture of the hand. On the basis of the above, a correction parameter for converting the mounting position displacement of the work with respect to the reference first position into a correction amount of the position and attitude angle of the hand is calculated, and the work is reproduced at the time of reproduction. The mounting position and the mounting posture angle when mounted on the work mounting table are measured by the measuring means, and the measured mounting position and mounting posture angle and the reference serving as the reference measured at the time of teaching Based on the position and posture angle of No. 1 and the correction parameter, the correction amount of the position and posture angle of the hand is calculated, and the calculated correction amount of the hand when the hand grips the workpiece. The position and posture angle are corrected.

[0009]

According to this structure, as shown in FIGS. 1 to 5, at the time of teaching, the reference position (Xs0, Xs0,
Ys0, θs0) to the work 12 placed on the hand 4
The measuring means 32 measures the first position (Xs0, Ys0) and the attitude angle θs0 that are the reference of the work when the work 12 is gripped by the hand 41 so that 1 has the desired relative position and relative attitude. , The work 1 when the hand 41 holding the work 12 is moved by a constant posture angle θT0
The second second position (Xs01, Ys01) is measured by the measuring means 32.

Then, the first position (Xs0, Ys0) and the second position (Xs) of the work 12 measured by the measuring means 32 are measured.
s01, Ys01) and the constant posture angle θT0 of the hand 12, the placement position deviation ΔXs1, ΔYs1, Δθs1 with respect to the first position (Xs0, Ys0, θs0) of the work 12 is calculated by the hand 4
1 position and attitude angle correction amount (ΔXT1, ΔYT1, Δθ
The correction parameters h and α for conversion into T1) are calculated.

At the time of reproduction, the mounting positions Xs1, Ys1 and the mounting attitude angle θs1 when the work 12 is mounted on the work mounting table 3 are measured by the measuring means 32, and the measured mounting position Xs1, Ys1 and the mounting posture angle θs1, the first position (Xs0, Ys0) and the posture angle θs0 measured during teaching,
Based on the correction parameters h and α, the correction amount (ΔXT1, ΔYT1, ΔθT1) of the position and posture angle of the hand 41 is calculated.

Then, the calculated correction amount (ΔXT1,
ΔYT1, ΔθT1) corrects the position (XT, YT) and posture angle θT of the hand 41 when the hand 41 grips the work 12.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a work gripping operation control device for a robot according to the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the outer appearance of a plate-like work supply system according to an embodiment. 2 is a system block diagram when a CCD camera is used as the sensor unit 32 of FIG.

As shown in FIG. 1, this plate-like work supply system is a system for supplying a work 12 to a robot 4 which conveys and supplies the work to a press brake. A supply device 50,
It is composed of a robot device 40.

The plate-like work supply device 50 further comprises a work loading table 1, a transfer device 2 and a measuring device 30, while the robot device 40 comprises a robot 4 and a controller 5. .

A plurality of plate-shaped works 12 to be conveyed by the robot 4 are stacked and stocked on the work stacking base 1 with their front and back surfaces aligned.

When a large number of works are stacked, the work load collapse prevention pin 11 is provided on the side surface 3 of the work 12 in order to prevent the work from being excessively displaced and the load collapsed.
It is erected on the base 1 so as to support points (may be four or more points). The position of the load collapse prevention pin 11 can be changed according to the size of the work 12. However, when the hand 41 of the robot 4 grips the work 12, high-precision control described below is performed so that the grip position does not shift on the robot 4 side.
When the pin 11 is positioned, it is not necessary to precisely adjust the position where the pin 11 is arranged, and it is only necessary to make a relatively rough adjustment according to the size of the work 12.

Further, in this embodiment, the gaps are provided between the pins 11 to allow the arm of the transfer device 2 to pass between them, but instead of the pin 12, the work 12 is replaced by a container. In the case of a structure for accommodating and supporting, the slit portion through which the arm of the transfer device 2 is inserted may be provided on the side surface of the container.

Further, if there is no fear of extreme displacement of the work 12 or collapse of the load, the pin 11 for supporting the work 12 or the container may be omitted.

The transfer device 2 takes out the works 12 stacked on the work loading table 1 one by one from the top, and the taken works 12 are measured by a measuring device 30.
It is a device for transferring onto the measurement surface 31 of the measurement table 3.

The transfer device 2 is a robot in which a hand 21 having an adsorbing tool such as a vacuum pad for adsorbing and gripping the work 12 is attached to the tip of an arm, and the arm 24 to which the hand 21 is attached is a direct arm. It is adapted to be moved up and down by an actuator 22 such as a moving cylinder, and the arm 24 is connected to the actuator 2 such as a rotary motor.
It is designed to be horizontally rotated by 3.

Therefore, these actuators 22,
The work 12 gripped by the hand 21 is transferred from the work stacking base 1 to the measurement surface 31 of the measuring base 3 by driving and controlling 23.

The measuring table 3 of the measuring device 30 has a measuring surface 31 on which the work 12 transferred by the transfer device 2 is once placed.

The measuring device 30 includes the measuring table 3, a sensor section 32 attached to the measuring table 3, and a data processing section 33.
It consists of and.

The sensor unit 32 and the data processing unit 33 are
The position and posture angle of the work 12 placed on the measurement surface 31 are measured. That is, in the sensor unit 32 and the data processing unit 33, as shown in FIG. 3, the sensor coordinate system Xs which is parallel to the measurement surface 31 and whose origin is a predetermined position of the measurement surface 31 is used.
The work center-of-gravity position (Xs1, Ys1) at −Ys and the posture angle θs1 that is the phase around the same center of gravity are measured.

As shown in FIG. 2, the sensor unit 32 and the data processing unit 33 process, for example, a CCD camera installed vertically above the measurement surface 31 and an image picked up by the CCD camera. It is composed of an image processing unit for obtaining the position and orientation of the work 12. When using a CCD camera, the measuring table 3 may also serve as an illumination table. In this case, as shown in FIG.
An illumination device 34 is arranged inside the measuring table 3 and the measuring surface 31
Is made of a material capable of transmitting light. For this reason,
The work 12 can be imaged in a good state.

Further, the sensor section is composed of a plurality of laser displacement gauges and a position data processing section for calculating the posture and the position of the work according to the distance between the laser displacement gauges detected by the plurality of displacement gauges and the work. 32 and the data processing unit 33 may be configured.

The data processing unit 33 has a reference position (Xs0, Ys0) in the previously stored sensor coordinate system Xs-Ys.
And the deviation amount ΔXs1, ΔYs1, Δθs1 between the reference posture θs0 and the position (Xs1, Ys1) of the work 12 detected by the sensor unit 32 and the data processing unit 33 and the posture θs1.
Is converted into a deviation amount (ΔXT1, ΔYT1, ΔθT1) expressed by the robot coordinate system XT-YT of the robot 4 according to a predetermined conversion procedure which will be stored in advance and is output to the controller 5.

The controller 5 is the hand 4 of the robot 4.
The operation program that describes the operation path of No. 1, the posture of the hand 41, the work content of the hand 41 (such as gripping or releasing the work) and the operation commands of peripheral devices (this system and the press machine, for example) according to the work order is stored. are doing. The operation program is given by teaching or the like.

The robot 4 is operated according to the work order described in the operation program, and the peripheral devices are operated by obtaining the operation timing according to the activation command described in the operation program.

The controller 5 and peripheral devices may be connected to an externally provided device having a sequence function to give them operation timing. In this way, the controller 5 controls the position XT of the hand 41 described in the above operation program in the robot coordinate system XT-YT,
The data of YT and attitude θT are corrected based on the correction amount (ΔXT1, ΔYT1, ΔθT1) output from the data processing unit 33, and the hand 41 has a position and attitude corresponding to the corrected data. Each axis of the horizontal multi-joint (4 axes) robot 4 is drive-controlled. As a result, the positions XT, YT and the rotation angle θT of the tip axis 4a of the arm of the robot 4 are changed as required, and the relative position and relative attitude of the hand 41 with respect to the work 12 on the measurement surface 31 are made desired,
The work 12 is gripped by the suction pad of the hand 41.

Next, the processing procedure when the sensor unit 32 is a CCD camera (FIG. 2) will be described with reference to the flowchart shown in FIG. 6 and the explanatory diagrams shown in FIGS.

Pretreatment First, the length Gs corresponding to one pixel of the CCD camera 32
In order to obtain (camera magnification) and the rotational deviation θTS0 of the sensor coordinate system Xs-Ys relative to the robot coordinate system XT-YT, as shown in FIG.
Set T0. Then, the center of gravity position G1 of the work 12 in a position where it can be held in the state of the hand 41, and the other two center of gravity positions G2 obtained by moving the work 12 by a known amount in the tool coordinate XT and YT directions. , G3 in the sensor coordinate system. So, these three points G1, G2,
From the value of G3, the magnification Gs of the CCD camera 32 and XT of the tool coordinate system (XT-YT-ZT) set on the robot tip axis 4a and Xs in the sensor coordinate system (Xs-Ys-Zs) with respect to the YT axis. , Ys axis inclination θTs0 is obtained.
Here, the Xs-Ys plane of the sensor coordinate system and the XT-YT plane of the tool coordinate system are assumed to be parallel. The data processing unit 33 needs only the amount of deviation between the reference position and the current position of the work 12 in the robot tool coordinate system, not the absolute position of the work 12, so the origin of the tool coordinate system is set in particular. do not have to.

The obtained Gs and θTs0 are stored in the data processing unit 33.
Is stored. With Gs and θTs0, the shift amount in the sensor coordinate system can be converted into the shift amount in the axial direction of the tool coordinate system at the position / posture PT0 of the hand 41.

Gs, θTs0, that is, the relationship between the robot coordinate system and the tool coordinate system is only when the setting of this system is changed when the robot 4 or this system is installed (for example, when the magnification of the lens of the camera 32 is changed). Then, it may be determined again (steps 101, 102, 20).
1, 301).

Next, the front and back surfaces of the works 12 are aligned and a predetermined number of the works 12 are stacked on the work stacking base 1. At this time, the placement position of the works 12 stocked on the loading platform 1 in the horizontal plane is set to a position where the hands 12 of the transfer device 2 can comfortably pick up the works 12.

Further, the load collapse prevention pin 11 is erected at an appropriate position on the work stacking base 1 so that the work 12 does not collapse.

In this embodiment, the operation of stacking the works 12 with their front and back aligned will be described, but it is also possible to carry out the work 12 without stacking them with their front and back aligned.

In this case, a feature (mark) or the like for distinguishing the front and the back is provided on the surface of the work, and the robot 4 is provided with a degree of freedom (axis) capable of reversing the work 12. . By doing so, the hand 41 holding the work 12 can be reversed as required according to the result of identifying the mark, and the front and back surfaces of the work 12 can be aligned (step 103).

Teaching process Next, the work placement position deviations ΔXs1, ΔYs1, and Δθs1 with respect to the reference position (Xs0, Ys0, θs0) of the work 12 are corrected by the correction amounts (ΔXT1, ΔYT1, ΔYT1, ΔYT1, ΔYT1, ΔYT1, ΔTs1) of the hand 41.
The correction parameters h and α for conversion into θT1) are calculated.

That is, as shown in FIG. 4, first, only one work 12 on the work loading table 1 is placed on the measurement surface 31 on the measurement table 3 by the transfer device 2. Next,
In order to validate the relationship between the two coordinate systems defined by the value of the parameter θTs0 stored by the above operation, the robot hand 4 is placed in the position / posture PT0 state, while the workpiece is rotated on the measurement surface 31.・ Move it, or
A desired relative position and relative position of the hand 41 with respect to the work 12 when gripping the work 12 by adding an operation of moving the robot hand 4 only in the tool coordinate axis direction from a position / posture PT0 state using a teaching box or the like. Teach the posture.

The values obtained by the above operation are used as the reference position / posture of the work 12 and the reference position / posture PT1 of the hand 41 when gripping the work.

That is, after the work 12 is placed, its position and
The center of gravity position (Xs0, Ys0) of the workpiece in the sensor coordinate system when the posture is corrected, and the inclination angle θs0 of the inertial spindle about the center of gravity axis are measured, and these are calculated as the reference position / posture angle (X
s0, Ys0, θs0) stored in the data processing unit 33,
In addition, the position of the hand 41 when gripping the workpiece in the above state
The posture is stored as the origin position / posture PT1 in the tool coordinate system.

At the time of the above teaching, it is also possible to perform the teaching by additionally operating the robot hand 4 by an arbitrary amount θTR in addition to the above operation. In this case, the parameter θTs
It is necessary to determine 0 again or to correct the rotation amount by the above-mentioned rotation amount θTR to obtain the correction amounts (ΔXT1, ΔYT1, ΔθT1) described later.

By the above-mentioned operation, it is possible to perform the teaching in which the relative position / posture is changed according to the difference in work contents such as the difference between the front bending work and the lateral bending work and the difference in the work type. Next, with the work 12 held by the hand 41, the hand 41 is swung by the known amount θT0 around the Z axis (origin of XT-YT) of the tool coordinate system (for example, around the robot tip axis 4a) (see FIG. 4). When the turning is completed, the work 12 is placed on the measuring surface 31 of the measuring table 3 again. Then, the work center of gravity position (Xs01, Ys01) in the sensor coordinate system at the end of the turning and the inclination angle θs01 of the inertial spindle about the center of gravity axis are measured and stored in the data processing unit 33 (steps 104, 105, 202). ,
302).

From the values obtained by the above operation, the distance h between the final turning position (Xs01, Ys01) of the work 12 and the reference position PT1 (tool coordinate origin) of the hand 41, and the reference position (Xs0, Ys0) and final turning position (X
The inclination α of the straight line connecting (s01, Ys01) to the tool coordinate axis YT is calculated by the following equation.

[0048] Here, if the relative position and the relative posture of the hand 41 with respect to the work 12 are different, the correction parameters h and α take different values accordingly (step 106). A series of operations for obtaining such correction parameters can be registered semi-automatically and easily since they can be registered in the controller 5 as a parameter setting robot and peripheral device operation program, except for the operation of setting the reference position of the work. It can be carried out. The operation of obtaining the correction parameter does not need to be performed again unless the relative position and the relative attitude are changed.

Further, teaching is performed for a series of operations in which the robot 4 picks up the work 12 from the measuring table 3 and conveys it to a predetermined position. In this way, the operation program of the robot 4 is created and stored in the controller 5.

Reproduction Process When the teaching process as described above is performed, the reproduction operation is performed and the actual work is started.

At the time of reproduction, the mounting positions Xs1, Ys1 and the mounting posture angle θs1 when the work 12 is mounted on the measuring table 3 are reproduced.
Is measured, and the measured mounting positions Xs1, Ys1 and the mounting posture angle θs1 and the reference position (Xs1
0, Ys0) and the reference posture angle θs0, and the correction amounts (ΔXT1, ΔYT1, ΔθT1) of the position and posture angle of the hand 41 are calculated based on the correction parameters h and α. Then, the calculated correction amount (ΔXT1, ΔYT1, ΔθT1)
The position (XT, YT) and posture angle θT of the hand 41 when the hand 41 holds the work 12 are corrected by the correction.

That is, first, the uppermost one of the works 12 ... Stocked on the work loading table 1 is adsorbed and gripped by the adsorbing tool of the hand 21 of the transfer device 2, and the vertical actuator 22 is operated to operate the hand 21. And raise it to a specified height. Further, the rotary actuator 23 of the transfer device 2 is operated to horizontally move the work 12 onto the measurement surface 31 of the measurement table 3. After that, the suction holding state of the hand 21 is released, and the work 12 is placed on the measurement surface 31
It is placed on top (steps 107, 108). Work 1
After the 2 is thus transferred, the actuator 22,
23 is driven and the hand 21 of the transfer device 2 returns to the top of the work 12 stacked on the work loading table 1 and stands by in a state of preparing for suction gripping of the next work 12. Since this series of operations can be easily realized by mounting a sequencer on the transfer device 2, the controller 5 only needs to send a start command to the transfer device 2.

Next, the work 12 placed on the measuring surface 31 of the measuring table 3 is imaged by the CCD camera 32, and the center of gravity (Xs1, Ys1) in the sensor coordinate system of this work 12 and its center of gravity are measured. The inertial spindle rotation angle θs1 of is measured (step 109).

Next, in the data processing unit 33, the work reference position (Xs0, Ys0) and the reference attitude angle θs0 which are already obtained and stored in the above step 104 and the actual mounting measured in the above step 109. Position (Xs1, Ys1)
And the deviations ΔXs1, ΔYs1, and Δθs1 with respect to the reference position and the posture are obtained from the deviation from the mounting posture angle θs1 with respect to the sensor coordinate system. Further, the amount of deviation in this sensor coordinate system is corrected by the correction parameters h, α, etc. obtained and stored in step 106, and the correction amounts ΔXT1, ΔYT1, Δθ of the position and orientation of the hand 41 in the tool coordinate system.
Convert to T1. The conversion formula is as follows.

[0055] (Step 110) In the controller 5, the robot 4 is operated so that the hand 41 takes the reference position / posture PT1 until the above calculation is completed, and when the correction amount is calculated, the hand 4 is moved. Reference numeral 41 is in the reference position / posture, and is in a standby state (steps 203, 204, 30).
3, 304, 305).

Therefore, the correction amount (ΔXT1, ΔYT1, ΔθT
1) is output from the data processing unit 33 to the controller 5, and the operation program is corrected. That is, when the controller 5 receives the correction amount, it corrects the movement command data in the operation program stored in advance according to the correction amount (step 205), and as shown by the arrow A in FIG.
Set the hand 41 to the reference position / posture PT1 (XT1, YT1, θT1)
Position and posture (XT1 + ΔXT1, YT1 + ΔYT1, θT1 +) shifted by the amount of calculation correction (ΔXT1, ΔYT1, ΔθT1) from
ΔθT1), and the hand 41 grips the work 12 in this displaced position and posture (steps 206, 3
06).

As a result, the hand 41 for the work 12
The relative position and relative attitude of are equal to those set at the time of teaching (see FIG. 5). The conveyance command after the hand 41 grips the work 12 is not corrected and is output as described in the operation program. As a result, the robot 4 can transfer the work 12 to the same position of the transfer destination in the same posture every time (step 20).
7, 307).

Thereafter, the operations after step 107 are repeatedly executed until there are no works 12 stocked on the work stacking base 1 (steps 111, 112, 20).
8).

In the embodiment, the sensor section 32 is a CCD.
Although the case where the sensor is a camera has been described, the sensor section may use pressure as a detection medium.

For example, a pressure pad (composed of a plurality of pads and outputting the magnitude of the pressure applied to each pad as a signal) is used as the sensor unit, and the distribution of the pressure signal output from the pressure pad is calculated. Accordingly, the position and orientation of the work placed on the pressure pad may be detected.

Further, instead of detecting the position and orientation of the work by the above-mentioned sensor unit provided with a plurality of laser displacement gauges, the position and orientation of the work can be detected by scanning one laser displacement meter. May be. In addition, a plurality of work loading platforms 1 are provided, the operating range of the hand 21 of the transfer device 2 is expanded, and the work is sequentially loaded from the respective loading platforms onto the measuring table to improve the work transfer efficiency. You may do it.

The work loading table 1 and the transfer device 2
Is indispensable for complete automation of the system, but it is also possible to omit these and manually transfer the work on the measuring table 3.

[0063]

As described above, according to the present invention, the relative position and relative posture of the robot hand with respect to the work placed on the work placing table can be arbitrarily changed to a desired one. The gripping position and gripping posture can be flexibly changed according to the change of the type of work and the change of work content.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external appearance of a system of an embodiment of a work gripping operation control device for a robot according to the present invention.

FIG. 2 is a block diagram showing the configuration of the system of the embodiment.

FIG. 3 is a plan view showing a state in which the hand of the robot of the embodiment grips a work, and is a diagram for explaining the contents of preprocessing.

FIG. 4 is a plan view showing a state in which the hand of the robot of the embodiment grips the work, and is a diagram for explaining the contents of the teaching process.

FIG. 5 is a plan view showing a state in which the hand of the robot of the embodiment grips the work, and is a diagram for explaining the content of the reproduction processing.

FIG. 6 is a flowchart showing a procedure of processing performed in the system of the embodiment.

[Explanation of symbols]

 3 Measuring stand 4 Robot 5 Controller 12 Work 32 Sensor part 41 Hand

Claims (2)

[Claims] 1. A work gripping operation control device for a robot, comprising: a control means for controlling the position and posture of the robot hand so that a work placed on a work mounting table is gripped by the robot hand. The control means includes a measuring means for measuring the position and the attitude angle of the work placed on the work placing table, and the control means, when teaching, the reference of the work when the hand is grasped by the hand on the work placing table. Becomes the first
Position and posture angle of the work is measured by the measuring means, and the second position of the work when the hand holding the work is moved by a fixed posture angle is measured by the measuring means, and is measured by the measuring means. The first that serves as a reference for the aforesaid workpiece
Position and second position and the constant posture angle of the hand, the placement position shift of the workpiece with respect to the reference first position is converted into a correction amount of the hand position and posture angle. A correction parameter for performing the calculation is calculated, and at the time of reproduction, the mounting position and the mounting attitude angle when the work is mounted on the work mounting table are measured by the measuring means, and the measured mounting position is measured. And a mounting posture angle, and a first position and posture angle which are the reference measured at the time of teaching,
A correction amount of the position and posture angle of the hand is calculated based on the correction parameter, and the position and posture angle of the hand when the hand grips the work are corrected by the calculated correction amount. The gripping motion control device for the robot. 2. The robot gripping operation according to claim 1, further comprising: a work stacking platform on which works are stacked; and a transfer device that takes out the work from the work stacking platform and mounts it on the work mounting platform. Control device.