JPS63254503A - Robot controller - Google Patents

Abstract

PURPOSE:To eliminate the useless arithmetic time by securing the common use of a buffer between the arithmetic processing task side and the shift processing task side. CONSTITUTION:A buffer memory BM contains the cyclic windows which have such sizes that can store the interpolation point information equal to (n) pieces and also the memory areas independent of each other for each interpolation point. In this case, the (n) corresponds to the maximum number of interpolation points existing between two pints on a moving locus and read out of a robot command data memory RCDM for each block. For an arithmetic processing task, an arithmetic pointer Pa is advanced by a step when the calculation is through with a single interpolation point regardless of the shift processing that controls the pulse distribution to a robot. A shift processing task which controls a pulse distributor PDC for the locus control so that the pointer Pa reaches each obtained axis value performs the shift processing independently of said arithmetic processing task. An executing pointer Pb is advanced by a step when it reaches a divided point of a target and prior to the shift to the next target point. Thus, the memory BM serving as a common buffer is used cyclically.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a robot control device for controlling the trajectory of a teach-and-play industrial robot.

(Prior art) In order for an industrial robot to function according to the required purpose, teaching the industrial Kawaguchi bot the work in advance 4! 1 I have a memory function that stores work data, and based on this data. A playback function is required to operate the robot hand at a predetermined speed while controlling its trajectory. In these current teach-and-play robots, the conventional calculation method for trajectory control is to teach the positions of discrete point sequences on the path in advance, and to Create command data, read out the robot command data one block at a time during playback, and write to the data. (Then I started moving my hand.

In this case, in a robot control device that stores data on the movement target position as the inclination of each axis of the arm, the division point on the path is calculated from the values of the starting point and ending point (and intermediate points) of the trajectory control stored in the data memory. The robot's motion is controlled while calculating it online.

(Problem to be Solved by the Invention) Generally, when controlling the trajectory of a multi-axis robot, in order to improve the accuracy of movement command output, it is necessary to increase the number of division points and shorten the interpolation interval. In this robot control device, data is transferred between a buffer memory that stores the calculation results of the coordinate values of dividing points on the path and a buffer memory that processes the calculated dividing points as the next operation target point. The calculation regarding the next division point cannot be executed until the output of the movement command regarding the currently targeted division-tile is completed, and as a result, depending on the speed of pulse distribution in the movement process, one division point may There may be idle time between the end of the calculation and the beginning of the calculation amount for the next division point.

In this way, the writing of distribution pulses to the servo circuit (servo LSI) for each axis and the calculation regarding the division points are performed in parallel, so it would normally be necessary to increase the number of division points to improve trajectory accuracy. Regardless, there is a problem in that the arithmetic processing capacity of the CPU is not fully utilized. Further, there is also the problem that it takes time to transfer data from the calculation buffer to the movement processing buffer, which limits the number of division points.

The present invention has been made in consideration of the above-mentioned point 1, and an object of the present invention is to provide a robot control device that eliminates wasted calculation time and executes robot trajectory control with good viscosity.

(Means for Solving the Problems) A robot control device of the present invention is a robot control device that controls the trajectory of a robot based on discrete point sequence data on a taught path. means for executing an arithmetic processing task of point information; a storage means for storing interpolation point information; a means for executing a movement processing task using the interpolation point information in the storage means; The control means which is controlled independently is Afl, and the storage means is used as a shared buffer for the arithmetic processing task and the movement processing.

(Function) In other words, in the robot control device of the present invention, the arithmetic processing task side and the movement processing task side control the interpolation point information stored in the storage means independently of each other, so the arithmetic processing task controls the interpolation point information stored in the storage means independently of each other. Calculations can be performed continuously, independent of movement processing.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a robot control device of the present invention. Robot command data memory RCDM
is connected to the processing device RPυ.

A series of robot command data has already been stored there through teaching operations. This robot command data includes a position data group expressing a scattered point sequence on the path as the tilt of each axis of the robot, and a block number identifying the execution order of each data group. The teaching operation panel ↑B has a mode select switch, and can select between a playback mode and a teaching mode. The read-only memory ROM stores a control program for controlling the processing bag mRPU.
When the reproduction mode is selected, data is read out one block at a time from the robot command data memory RCDM, and arithmetic processing for converting each axis inclination into orthogonal coordinate values of the robot's TCP is controlled.

The figure shows the servo motor SN for only one axis, but the servo circuit for each axis includes a pulse distributor PDC that outputs distributed pulses from the incremental amount for each axis calculated by the processing bag at RPU, and a servo motor. It consists of a servo unit SVu that controls the rotation, a pulse generator PC that feeds back the rotation signal from the servo motor 5ll, etc., and each time the hand moves a predetermined direction, the remaining movement? Or process the current position for each axis? Compute with cfi RPU and turn on data memory
to be memorized.

B is a buffer memory having a block configuration as shown in FIG. 2, and is connected between the processing unit RPU and the pulse distributor POC. This buffer memory BM is n
It is a cyclic window large enough to store interpolation point information for each interpolation point, and constitutes an independent storage area for each interpolation point. Corresponds to the maximum number of interpolation points between points. The calculation processing task involves calculating the coordinates of interpolation points and sequentially inverting them to obtain the tilt of each axis, which is performed independently of the movement process that controls pulse distribution to the robot, that is, without synchronization. When the calculation regarding one interpolation point is completed, the calculation pointer Pa is advanced by one. The movement processing task that executes trajectory control by controlling the pulse distributor PDC so as to reach y:F)t=each axis axis inclination also performs movement processing independently of the calculation processing task,
When the target dividing point is reached, the execution pointer pb is advanced by one before moving to the next target point.

In this way, if the buffer memory BM configured as a shared buffer is used cyclically, the arithmetic processing task only has to make sure that its own pointer Pa does not catch up with the execution pointer pb that manages the movement processing task. Often, the processing bag 21RP has nothing to do with the actual movement processing.
Interpolation points on the arbitrary side can be calculated one after another using υ. Then, on the movement processing task side, the own pointer p
Only by confirming that the calculation pointer Pa is located ahead of point b, movement control along the commanded trajectory can be executed.

The flowchart in FIG. 3 shows an example of the trajectory control calculation procedure of the above embodiment. After reading the point sequence data of the starting point and the ending point from the data memory RCDM in step a, it is possible to proceed with the arithmetic processing task and the movement processing task independently as steps b and step C, respectively.
After step b, the calculation pointer Pa is advanced by one step in step d), and after step C, the execution pointer pb is similarly advanced by one step in step e), and then the relationship between each pointer Pa and Pb is determined. In step f, it is possible to confirm only Pa>Pb and execute each task one after another. If the end of the arithmetic processing task is confirmed in step g, and the end of the movement processing task is also confirmed in step h, the trajectory control between the initially given starting point and the ending point is completed, and the contents of the buffer memory BM are is cleared.

Note that the storage capacity of this buffer memory is sufficient if it constitutes an independent storage area for each interpolation point, and the capacity corresponding to the maximum number n of interpolation points between two points on the movement trajectory is sufficient. Furthermore, since the time required for data transfer is shorter than that of the conventional method, such a large capacity is not necessarily required.

(Effects of the Invention) As explained above, according to the present invention, the buffer on the arithmetic processing task side and the buffer on the movement processing task side are shared, eliminating wasted calculation time. It is possible to provide a robot control device that can read out point sequence data necessary for trajectory control at high speed and is effective in improving control accuracy.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram showing an example of the configuration of a buffer memory, and FIG. 3 is an explanatory diagram showing the operation of the device of the embodiment. RPU: Processing unit, RCDM: Robot command data memory, B: Buffer memory, TB: Teaching operation panel. Patent applicant: Representative of FANUC Co., Ltd. Patent attorney: Minoru Tsuji Figure 1 Figure 3

Claims (2)

[Claims] (1) In a robot control device that performs trajectory control of a robot based on discrete point sequence data on a taught path, means for executing an arithmetic processing task of interpolation point information of the point sequence data, and interpolation point information , a means for executing a movement processing task based on the interpolation point information of the storage means, and a control means for controlling the arithmetic processing task and the movement processing task independently of each other, A robot control device characterized in that it is used as a shared buffer for arithmetic processing tasks and movement processing. (2) A patent characterized in that the storage means has a storage capacity to store interpolation point information of the maximum number of interpolation points between two points on the movement trajectory, and has an independent storage area for each interpolation point. A robot control device according to claim (1).