JPH04299709A - Automatic position correcting method - Google Patents

Abstract

PURPOSE:To shorten the overall tact time in a robot job where the position error of a work is detected to a teaching point and then corrected by shortening the time needed for detection and correction of the work position error. CONSTITUTION:The P1-1-P13-1 are taught to the works 7 and 8, and the error is detected between the work 7 set at P2-1 and P5-1 and a teaching point. An instruction is carried out so that the detected error is written into a designated memory position, and such instructions are shown after the P2-1 and P5-1 so as to correct the teaching position with the error value. Then an instruction is shown to read the error of the work 7 produced between P10-1 and P2-1 and to correct this error. If both works 7 and 8 are set at the positions shown by the broken lines, the error of the work 7 is corrected at the P10-1. As a result, the correction is possible at all positions just with detection of the error between the P2-1 and P5-1. Then the robot working time is extremely reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic position correction method for automatically correcting the positional deviation of a workpiece during work using a robot.

0002

2. Description of the Related Art When working with a robot, problems arise in the relative positional accuracy of the work to be worked on relative to the robot and the dimensional accuracy of the work to be worked on. Conventionally, if a robot is not equipped with a detector to detect the accuracy of the robot, the previously taught position must be corrected before the robot performs the work. On the other hand, if the robot is equipped with a detector that detects these accuracy, the positional deviation information obtained by the detector is stored separately from the previously taught position for each taught position, and when the industrial robot is working, The position of the robot operation was automatically corrected while correcting the positional deviation obtained by the detector relative to the taught position for each taught point.

0003 3,

[Detailed description of the invention]

However, in the method described above in which the robot performs the work while detecting the positional deviation of the workpiece, time is lost because the detector detects the positional deviation at each taught point. The problem was that it took a long time.

The present invention aims to solve the above problem, and once the amount of deviation between the taught position and the actual position is detected by the detector, the same amount of deviation is detected for the workpiece to be worked on. There is no need to detect the amount of deviation each time.
The purpose of the present invention is to provide a time-efficient method for automatically correcting the position of a robot.

[0005]

[Means for Solving the Problems] In order to achieve the above object, in the present invention, in the teaching mode of the robot,
The amount of positional deviation of the workpiece is calculated from the command to instruct the position, posture, and movement, the command to detect the workpiece with the detector, the workpiece position detected by the detector, and the teaching position written in the memory. command to correct the deviation amount by writing to a specified position in the memory, read the deviation amount of the workpiece written in the memory from the specified position in the memory, and correct the taught position by the deviation amount from the workpiece to be worked on. In this method, a command is given, such as a command to stop correcting the teaching position based on the amount of deviation from the workpiece, and the workpiece is moved while sequentially executing the taught commands in the operation mode. The robot detects the deviation amount between the taught position and the workpiece position and writes it to the set position in the memory, or reads the deviation amount of the workpiece written in the memory from the set position in the memory. Move the arm position while correcting it to the teaching point based on the amount of deviation from the workpiece.

[0006]

[Operation] During operation, the detector detects the amount of positional deviation of a specific point on the workpiece, calculates the amount of deviation from the taught position, writes the amount of deviation to the specified position in the memory, and updates it as necessary. In order to operate while correcting the deviation amount of the taught position by reading the deviation amount, when the teaching point is to be corrected by the same deviation amount as the already detected deviation amount, the deviation amount is read from the memory and the teaching point is corrected. Therefore, the operation of detecting the amount of positional deviation with the detector again and the time of calculating the positional deviation are unnecessary, and the takt time can be shortened.

[0007]

[Embodiment] Fig. 1 is a diagram conceptually showing the configuration of a robot system used in an embodiment of the present invention. In Fig. 1, 1 is a robot arm, 2 is a teaching device, 3 is a robot control device, and 4 is a control device. A memory built into the device 3, 5 joints of the robot, 6 a detector, and 7 and 8 workpieces.

In the robot system configured as described above, the teaching device 2 writes robot teaching data necessary for working on the workpieces 7 and 8 to the memory 4, and the detector 6 detects the workpieces 7 and 8. , the control device 3 sequentially executes commands taught in the memory 4, and the work is performed while correcting the amount of positional deviation of the workpieces 7 and 8 to be worked on.

FIG. 2 is a perspective view of the workpieces 7 and 8 to be worked on, and FIG. 3 is a view of the workpieces 7 and 8 viewed from directly above. Further, the workpieces 7 and 8 shown by solid lines in FIG. 3 are in the teaching position, and the workpieces 7 and 8 shown by broken lines are in the actual position. P1-1 to P13-1 in FIG. 3 are teaching positions of the robot 1. P1-1 is the position where the operation starts, P2-
1 and P11-1 are the positions where work on target work 7 is started, P5-1 and P8-1 are positions where work on target work 8 is started, and P3-1 and P12-1 are positions where work on target work 7 is started. End position, P6-1 and P9-1
are the work end positions of workpiece 8, P4-1, P7-
1 and P10-1 are work preparation positions, and P13-1 is an operation end position. At the teaching position of P2-1, the amount of deviation between the detected position of the workpiece position 7 and the teaching position of P2-1 is written in the position A in the memory 4, the deviation from the teaching position is corrected, and the following steps are performed. The teaching position of P5-1 is a command to operate while correcting the teaching position with the deviation amount written in the A position in the memory 4, and the teaching position of P5-1 is the position where the workpiece 8 to be worked is detected and the teaching position of P5-1. The amount of deviation from the teaching position is written in the position B in the memory 4, the deviation amount from the teaching position is corrected, and the subsequent teaching position is written in the position B in the memory 4.
The instruction to operate while correcting the taught position with the amount of deviation written in the position, for the teaching position of P10-1, read out the amount of deviation written in the A position in the memory 4 and correct the subsequent taught position. The command to operate while the memory 4
is taught. P1-1 to P13- in driving mode
If work 1 is performed sequentially, P1-1 to P2-1, P
It operates sequentially from 2-1 to P2-2, and from P2-2 to P3-2, and at P10-2, the amount of deviation of the workpiece 7 to be worked on is stored in the memory 4.
Since the robot reads out the A position within and moves while correcting the subsequent taught position, the robot moves from P10-2 to P11-2, from P11-2 to P12-2, and from P12-2 to P13-2 and completes the work. do. That is, in the embodiment shown in FIG. 3, it is only necessary to detect the positions of two points, P2-2 and P5-2, and the operation time for detecting the positions of all other points is omitted, which greatly reduces the takt time. This is a shortened operation.

0010

[Effects of the Invention] As is clear from the above embodiments, once the amount of deviation between the workpiece and the taught position is determined by the detector using the method of the present invention, the amount of deviation is written to or read from the specified position in the memory. Therefore, when a robot works on a workpiece with the same amount of deviation, the robot reads the amount of deviation from the memory location where the amount of deviation is written and corrects the taught position while the robot performs the work. Since the work can be done by simply moving the robot, the robot operation of detecting the amount of deviation between the teaching position and the workpiece at all teaching positions is no longer necessary, making it possible to significantly shorten the takt time.

[Brief explanation of drawings]

[Figure 1] Conceptual diagram of the configuration of the industrial robot used in the present invention

[Figure 2] Perspective view of the workpiece to be operated by the robot

[Figure 3] Plan view showing the relationship between the robot workpiece and the robot trajectory

[Explanation of symbols]

1 Robot arm 3 Control device 4 Memory 6 Detector 7, 8 Target work

Claims (2)

[Claims] Claims 1: A robot arm comprising at least one rotational or linear axis and a position detector for the axis; a control device having a rewritable memory to move the robot arm according to instructions; It consists of a detector that is attached to detect the workpiece to be worked on, the operation mode is divided into at least a teaching mode and a driving mode, and a command and detector that instruct the position, posture, and movement of the arm of the robot body in the teaching mode. The command to detect the workpiece to be worked on is to calculate the positional deviation of the workpiece from the position of the workpiece detected by the detector and the position written in the memory, and write the deviation amount to the specified position in the memory. A command to correct, a command to read the deviation amount of the workpiece written in the memory from a specified position in the memory and correct the deviation amount of the robot arm position from the workpiece, and a command to read out the deviation amount of the workpiece written in the memory from the specified position in the memory, and to correct the deviation amount of the robot arm position from the workpiece workpiece. In an automatic correction method for the position of a robot that moves while sequentially executing the commands taught in the operation mode by teaching a command to stop correcting the amount of deviation from the position, the workpiece is detected by a detector during operation. , writes the amount of deviation between the position written in the memory and the detected position of the workpiece to be worked on to the set position in the memory, or reads the amount of deviation of the workpiece written in the memory from the set position in the memory. An automatic position correction method characterized by moving the robot arm while correcting the position according to the amount of deviation of the teaching point from the workpiece. [Claim 2] At least one position is specified in order to calculate the amount of positional deviation of the workpiece to be worked on from the position of the workpiece detected by the detector and the position written in the memory and write or read it in the memory. 2. The automatic position correction method according to claim 1, wherein the method is as follows.