JPH01220003A - Method for controlling learning of industrial robot - Google Patents

Abstract

PURPOSE:To improve learning efficiency and to stabilize action by obtaining not only a positional deviation but also the deviation between a reproducing speed and a target speed and modifying a teaching value at the time of a next reproducing action based on the deviations. CONSTITUTION:In addition to the deviation between a target position and a reproducing position, the deviation between the reproducing speed and the target speed is obtained and the contents (teaching value) of a teaching value memory 2 is modified by the deviations. A target value memory 1 reads out the storage contents of the teaching value memory 2 and operates an arm through an actuator 6. Since the teaching modification of the teaching value is carried out by including not only the deviation of the positions but also the deviation of the speeds like this, the number of modifications can be decreased and a stable convergence result can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a learning control method for industrial robots, repetitive positioning devices, and the like.

(Prior Art) Conventionally, a controlled object is regenerated according to a taught value stored in a memory, and a deviation between a target value and a reproducing trajectory is measured during the reproducing operation, and this deviation is used as the taught value during the next reproducing operation. A learning control method for an industrial robot is known in which the teaching value for reproducing the controlled object is sequentially corrected by adding the teaching value to the value, thereby improving the accuracy of the trajectory of the reproducing operation.

According to this learning control method, the taught value is sequentially corrected according to the deviation between the target value and the actual playback trajectory, so as the playback operation is repeated several times, the taught value becomes closer to the target value. It will converge within the allowable error range. For this reason,
It is possible to control the work trajectory of the reproducing operation according to the target value.

(Problem to be Solved by the Invention) In the conventional technology, the taught value was corrected only by the deviation between the target position and the playback position, but in this method, many corrections were made before the playback trajectory converged within the tolerance range of the target trajectory. Since it was necessary to repeat the playback operation, stable operation was not always obtained.

The present invention has been made to solve these problems, and an object of the present invention is to provide a learning control method for an industrial robot that can improve learning efficiency and operate stably. It is.

(Means and effects for solving the problem) The present invention calculates not only the positional deviation but also the deviation between the playback speed and the target speed,
Based on these deviations, the teaching value for the next reproduction operation is corrected.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of an industrial robot control device to which the present invention is applied, and the position information of each point on the motion trajectory of an arm (not shown) to be controlled. A target value memory 1 stores the target value as a target value, a teaching value memory 2 stores the target value corrected by teaching correction as a taught value, and stores arm position information relative to the target value detected by the position detector 3 as a reproduced value. Find the deviation between the playback value stored in the playback value memory 4 and the target value, and then find the deviation between the playback speed and the target speed. ), and reads out the contents of the target value memory 1 or the taught value memory 2 to operate the arm via the actuator 6.

FIG. 2 is a flowchart showing the procedure for performing teaching correction, and steps 10 to 13 are the first regeneration operation.

In this case, the same position information as the contents of the target value memory 1 is initially stored in the taught value memory 2 by the teaching operation by the operator.

First, in step 10, the target value at each point on the motion locus stored in the target value memory 1 is read out by the arithmetic unit 5, and each target value is given to the actuator 6, so that the arm moves to each target value. Correspondingly driven.

At this time, the actual operating position is detected by the position detector 3 for each target value and sequentially stored in the reproduction value memory 4 as a reproduction value (step 11).

Once the reproduction value for the current target value is obtained, a feedback calculation is performed to add the deviation to the next target value (step 12), and the next target value is given to the actuator 6 based on the result of this calculation. . As a result, the trajectory changes according to the target value stored in the arm target value memory 1.

When the first reproducing operation using all the target values is completed in this way, steps 14 to 18 enter the teaching value correction step.

First, the target speed and regeneration for each control cycle are calculated (
Step 14). That is, the target position MO(t
), the playback position M2(t), and the control period ts, the target speed is found as follows: VO(t)=Ot -Ot-tss The playback speed is found as V2(t)=-2t-ts.

Next, the deviation between the target speed and the playback speed is VO(t)−V2 (
t) (step 15).

Next, the deviation between the target position and the playback position is MO(t) - M2(t
) (step 16).

Next, the taught value is corrected (step 17).

That is, if Ml (t) is the taught value, Ml (t)' is the corrected taught value of 1, and K2 is a constant, then M 1 (t)
' = M 1 (t) + K 1 (MO(
t) -M2 (Taught value M in the taught value memory by t)
l(t) is corrected, and the corrected taught value Ml(t
)' is used as the next teaching value.

Next, when such correction is completed for all of the taught values, the corrected taught value M1(t)' is read out, the reproduced value is stored, and the feedback calculation is repeated.
Performed for all taught values (steps 19 to 22)
. If the motion trajectory of this arm is not within the allowable error range, the process returns to steps 14 to 18 again, and the teaching correction of the taught value is performed, and if it converges within the allowable error range, the teaching correction is performed. finish. Subsequent reproductions are performed using this modified teaching value.

(Effects of the Invention) The present invention performs teaching correction of the taught value by taking into consideration not only the position deviation but also the velocity deviation, so that the number of corrections can be reduced and stable convergence results can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an industrial robot control device to which the present invention is applied, and FIG. 2 is a flowchart showing a teaching correction procedure. l...Target value memory 2...Taught value memory 3...Position detector 4...Reproduction value memory 5...Arithmetic unit 6...Instruction actuator

Claims (1)

[Claims] The controlled object is regenerated by reproducing the controlled object according to the taught value stored in the memory, and measuring the deviation between the target value and the reproducing trajectory during the reproducing operation and adding it to the teaching value during the next reproducing operation. In a learning control method for an industrial robot that sequentially corrects the teaching value for operation, in addition to the deviation between the target position and the playback position, the deviation between the playback speed and the target speed is also determined, and the next playback is performed based on these deviations. A learning control method for an industrial robot characterized by modifying a teaching value during operation.