JPH0212711B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Application of the Invention] The present invention is directed to a robot system in which a plurality of robots have the same overlapping work area (hereinafter referred to as an interference area). This invention relates to a method for preventing collisions between robots for automatically inserting a cancellation command into robot control data. [Prior Art] Generally, when there is an interference area between a plurality of robots, there is a risk that the robots will collide with each other due to the combination of operations performed by each robot. If a collision occurs between robots, there is a risk that they will not only run out of control and destroy surrounding equipment, but also
The robot's control axis may become distorted. The operation of this control axis is generally taught to each robot individually, and if the above-mentioned deviation of the control axis occurs, the previously taught data becomes unusable. Therefore, re-teaching all the data requires a large amount of man-hours, so preventing collisions between robots has been an important issue. As a conventional method for this purpose, there is a method in which robots that are at risk of colliding with each other send and receive signals informing each other of their operations to prevent collisions. This will be explained with reference to a system configuration diagram of an example of a conventional collision prevention system between robots shown in FIG. First, the robot 1a uses its gripper GRP1.
Assume that the robot 1b operates to pick up the part W1 on the workbench T and the part W2 on the workbench T with its gripper GRP2. In this case, in order to prevent collisions around the workbench T, the control device 2a corresponding to the robot 1a
is, for example, at point X, and the control device 2b corresponding to the robot 2a is, for example, at point X, respectively. Send it to the other party. That is, the control device 2a first confirms that there is no timing signal from the control device 2b at point
The operation of GRP1 is continued to cause it to enter the interference area. After that, even if the robot 1b is to pick up the part W2, it must wait at point Y. When the robot 1a finishes its work and returns to point X, the control device 2a resets the timing signal to the control device 2b. As a result, the control device 2b sends a timing signal to the control device 2a and then controls the robot 1b to take the part W2. In this way, collision between the robots 1a and 1b in the interference area is prevented. However, in such a conventional method,
The instruction for turning on and off the timing signal must be created by the operator each time the robot is taught to operate. When the number of target operations increases, all combinations of operations must be considered, which not only requires a great deal of effort, but also poses a risk of creating the instructions by mistake. [Object of the Invention] The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to automatically insert into robot control data instructions for occupying and canceling the interference area necessary to prevent collisions between robots. However, it is an object of the present invention to provide a method for preventing collisions between robots, which can reduce the number of man-hours for creating instructions and improve reliability. [Summary of the Invention] The structure of the inter-robot collision prevention method according to the present invention is such that when any one of a plurality of robots is working in an interference area and the surrounding area, the control device of that robot operates in the interference area. In addition, when the control device receives the occupancy signal, it sends the occupancy signal for the same surrounding area to the control device of each other robot, and when the control device receives the occupancy signal, it sends the occupancy signal to the interference area and the surrounding area to each robot. In a robot system having a function of preventing collisions between robots by forcing the robots to wait for the robots to enter the robot, a visual device is provided for detecting the entry and exit of the robots with respect to the interference area or at least a restricted area including the interference area, and By sending a signal to the control device of each robot, the corresponding control device automatically inserts a command to occupy or release the occupation of the interference area or restricted area into the robot control data based on the signal. This is what I did. [Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described based on the drawings. Fig. 2 is a method block diagram of an embodiment of the method for preventing collision between robots according to the present invention, Fig. 3 is an explanatory diagram regarding the interference area, and Fig. 4 is an explanation of entering and exiting the interference area. 5 is an explanatory diagram of the robot control data, and FIG. 6 is a flowchart of the same. Here, 11a and 11b are arms, respectively.
ARM1, ARM2 and Gritsupa GRP1, GRP
A robot that operates 2 to perform a prescribed task, 12
13 is a communication line between the control devices 12a and 12b, 14 is a visual device (for example, an image processing device using a television camera), and 15 is a connection from the visual device 14 to the control device. 12
The signal lines 21a, 21b for a, 12b are:
Operating areas of robots 11a, 11b, 22a, 2
2b is the free area (operating area 21a, 21b
23 is an interference region where the operating regions 21a and 21b overlap each other (shaded region); 24 is an interference region 2
3, and has a simple shape (for example, a rectangular parallelepiped) to facilitate control and processing. In this method, for each robot control data of each robot 11a, 11b, free areas 22a,
22b to the interference area 23 or the restricted area 24 (interference starting point P _s ) and the point transferring (exiting) in the opposite direction (interference ending point P _e ),
The positional information of each of these points and commands for occupying and unoccupying the interference area 23 and restricted area 24 are automatically inserted. First, it is assumed that the command word of the robot control data is as follows. (1) FROM P...Starts operation from point P. (2) GOTO P...Move to point P and stop. (3) THROUGH P...Simply passes through point P. (4) GRIP ON, GRIP OFF…Grippa GRP1,
Close (ON) and open (OFF) GRP2. (5) SPEED v…Move at speed v. (6) INCHK S...occupies specific area S. (7) OUTCHK S...Cancels the occupation of specific area S. Here, the specific area S refers to the interference area 23 or the restricted area 24. Next, the visual device 14 detects each robot 11a, 11b (arm ARM1, ARM
2 or grippers GRP1, GRP2), and detects and determines the interference start point _Ps and interference end point _Pe , and sends the information to each control device 12a, 12b through the signal line 15. Recognition of objects existing within the visual field of the specific region S is performed as follows. In other words, the object to be recognized (robot 11
a, 11b) are colored in advance in a color different from that of other objects existing within the field of view. If it is originally different, it can be left as is. The field of view fixed in this way is imaged by a color TV camera, and the image light is divided into three colors of red, green, and blue, photoelectrically converted, and then quantized by an image processing device (visual device 14). Create three digital images. Regarding this image, the following processing is performed regarding the specific area S set in advance in the image processing program. From this digital image, pixels having a digital characteristic value of the color of the object are searched, and based on the number of pixels, it is recognized whether the object (robot) exists in the specific area S or not. Such recognition processing can be performed at fixed time intervals, for example, about 0.1 seconds. The entry of the object into the specific area S and the exit from the specific area S are determined through two consecutive recognition processes. That is, at the time of each recognition process, the entrance or exit of the object is determined based on the result of the current recognition process and the result of the previous recognition process based on the following table.

〔Effect of the invention〕

As described in detail above, according to the present invention, robot control data in which commands for occupying and unoccupying the interference area are automatically created is created simply by performing normal teaching. Not only does this reduce labor, but it also eliminates errors during data creation due to operator errors, resulting in significant improvements in safety and reliability.

[Brief explanation of drawings]

FIG. 1 is a system configuration diagram of an example of a conventional method for preventing collisions between robots, FIG. 2 is a system configuration diagram of an example of a method for preventing collisions between robots according to the present invention, and FIG.
The figure is an explanatory diagram regarding the interference area, and FIG.
Figure 5 is an explanatory diagram of entering and exiting the interference area.
FIG. 6, which is an explanatory diagram of the robot control data, is a flowchart of the same. 11a, 11b...robot, 12a, 12b...
Control device, 13... Communication line, 14... Visual device, 15
...Signal line, 21a, 21b...Operating area, 22a,
22b...Free area, 23...Interference area, 24...Restricted area.

Claims (1)

[Claims] 1. When any of multiple robots is working in the interference area and the surrounding area of the interference area,
The control device of that robot sends the occupancy signal for the interference area and surrounding area to the control devices of other robots, and when each control device receives the occupancy signal, In a robot system having a function of preventing collisions between robots by forcing robots to wait to enter the interference area and its surrounding area, a visual system that monitors the interference area or at least a restricted area that includes the interference area is provided. The device detects the entry and exit of the robot, sends the detection signal to the control device of each robot, and the control device that receives this detects the interference area or the above interference area in the robot control data based on the detection signal. A method for preventing collisions between robots, characterized by automatically inserting commands to occupy and release restricted areas.