JPS61256409A - Control system for industrial robot - Google Patents

Abstract

PURPOSE:To secure the working of a robot with high precision without using a special device by comparing the distance needed for deceleration with the deceleration enable distance to decide the speed variation in a deceleration mode. CONSTITUTION:A signal is supplied from a teaching device 4 via an operation key 2 of a robot controller 1. Then a robot main body 5 works according to said signal input to display the desired operating commands and data on a display screen 3. A position data display function module is added to the controller 1 together with a speed teaching function module and an acceleration teaching function module. These modules are called out by the device 4. The teaching points and the speed and acceleration between these teaching points are stored in a memory 6 connected to a CPU 7 of the controller 1. Then a servo command is given to a servo circuit 9 from the CPU 7, and an action end signal is supplied to the circuit 9. Thus a robot can be controlled with high precision without using a special device.

Description

[Detailed description of the invention] [Field of application of the invention] The non-invention relates to the control method of industrial robots, and
ili! This invention relates to a control system suitable for robots that require fast and accurate movements.

[Background of the invention]

When changing the speed between teaching points continuously, the distance between teaching points where acceleration/deceleration is actually possible may be shorter than the interval required for acceleration/deceleration. In particular, when decelerating and stopping, if the deceleration section is shorter than the section required for deceleration, there is a problem that positioning at the stopping point becomes inaccurate due to a sudden change in speed. Note that US Pat. No. 3,909,600 is cited as related to this type of control method.

[Purpose of the invention]

An object of the present invention is to provide a control method for an industrial robot that softens speed changes at a stopping point and improves positioning accuracy at the stopping point when the section where deceleration is possible is shorter than the section required for deceleration. It is in.

[Summary of the invention]

If the deceleration possible section is shorter than the 8 sections required for deceleration, it is necessary to rapidly change the speed within the deceleration possible section. Therefore, in the present invention, if the speed is suddenly changed at the end point of the deceleration possible section, the positioning accuracy at this point will decrease, so the speed is suddenly changed at the start point of the deceleration possible section, and the new speed at this time is This is calculated backwards from the actual distance of the section where deceleration is possible.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an industrial robot control method according to the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a robot control device, 2 is an operation key, 3 is a display surface of a display device, 4 is a teaching device, and 5 is a robot body.

When the operation key 2 inputs a signal from the teaching device 4 or the like, the robot control device kl functions to cause the robot body 5 to operate based on the signal, and at that time, displays necessary operation commands and data on the display screen 3. It works to make things happen. In addition, this control device fi [1 is equipped with a function module for teaching position data, a function module for speed teaching, and a function module for teaching acceleration.The keys to call these function modules are in the teaching device &4. 114C are reserved for the position data teaching key, stop point teaching key, speed teaching key, and acceleration teaching key, respectively.

Next, FIG. 2 shows the internal structure of the robot control device kLl, where 6 is the teaching point, the construction distance between the teaching points, and addition 2! ! 7 is the CPU, 8 is the servo circuit OC
! PUT outputs a servo command 9 to the servo circuit 8, and the servo circuit 8 outputs C! Returns operation completion signal lO to PUT 0 Next, the operation of this embodiment will be explained. The teaching work is performed in the same way as a normal control 4I device. That is, for one position, when the robot main body 5 is guided to a desired point by the teaching device fi4 and the position data teaching key on the teaching i#ckd is pressed, the position is stored in the memory 6 from K. At this time, when the speed setting key on the teaching device 4 is pressed, the speed between the teaching points is stored in the memory 6. Addition #: Acceleration at the time of hesitation is stored in the memory 6.

Next, the operation during playback will be explained.

When the robot performs the work taught as described above by playing back, at step 0, which is configured so that when the robot decelerates to %, the processing according to the flowchart shown in FIG. From the memory 6, the next speed Vn/acceleration a2 section start point PO1 section end point.

Read out.

Step ■ So, where is the start of the section where the step started?
, %section end point P, determine the length D of this section.

In step ■, the distance d required to decelerate the next taught speed vnK is calculated from the speed VC taught in the section (Po-P, interval) in which the robot's hand is currently moving.〇 In step (2), the section length determined in step (2) is compared with the distance d required for deceleration determined in step (2).

If D > d, then step ■, distance (D
-d) Move the robot's hand using Speed & VC while moving forward, and jump to Step ■.

If -D<(l, that is, if the distance required for deceleration is longer than the section length, proceed to step ①, and at the specified acceleration #La, the speed Jt that can be reduced by the speed VnK during the section length
Recalculating v'c, and decelerating the speed toward the total Vn with a step ■,
Move the robot's hand toward the end point P1 of the section.

FIG. 4 shows the speed bump when the algorithm shown in FIG. 3 is followed. Fig. 4 ((1) is the speed slam when Dea, that is, the distance force required for deceleration is the speed bump when is smaller than the section length.

As shown in FIG. 4(b)K, even if the speed is unavoidably changed discontinuously, the change is made at the start point P0 of the deceleration section, so there is little effect on the end point P of the deceleration section, and the end point P1 of the section is changed. In this case, it is possible to continuously change the speed to the next time.

〔Effect of the invention〕

According to the present invention, even when the section where deceleration is possible is shorter than the section required for deceleration, the rapid change in speed is performed at the starting point of the section where deceleration is possible, so the trajectory of the robot hand during a low-speed shift is unstable. In the case where the vehicle stops after decelerating on a mountain pass, it is possible to greatly improve the positioning accuracy at the stopping point.

The present invention makes use of most of the functions conventionally equipped in conventional robot systems, adds only a small amount of functionality, and can be implemented without requiring any special equipment. Therefore, it is possible to easily provide a low-cost industrial robot control device that allows the robot to operate accurately.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram showing an embodiment of an industrial robot control device according to the present invention, FIG. 2 is an internal configuration diagram of an embodiment of the invention, and FIG. A flowchart for explaining the operation, FIG. 4 is an explanatory diagram showing the operation of an embodiment of the present invention. 1... Robot control device, 2... Operation key, 3...
...Display surface, 4...Teaching device, 5...Robot body, 6...Memory, 7...CPU, 8...Servo circuit, 9...Servo command, 10...Operation Completion signal '$ 1 Figure robot me #1 Junkosho 1 [ Figure 2 $ 4 Figure (: 1 (b)

Claims (1)

[Claims] In a robot control device that has a storage device that stores information regarding teaching points and robot movements between teaching points, determining a speed change during deceleration by comparing the distance required for deceleration and the distance that can be decelerated. A control method for industrial robots featuring: