JPH07136976A - Multiple robot interference avoiding method - Google Patents

Abstract

PURPOSE:To prepare a program easily without taking account of mutual interference between robots by comparing the sum of the length of the second arms of the respective robots and the hand radii with the distance between the end points of the first arms of the respective robots at two points in the action starting position and action target position of each robot. CONSTITUTION:Distance a, b between the end point of a first arm 302 at the A-point of a robot 1 and the end points of a first arm 307 at the C- and D-points of a robot 2 are computed, and distance c, d between the end point of the first arm 302 at the B-point of the robot 1 and the end points of the first arm 307 at the C- and D-points of the robot 2 are computed. The minimum value among a, b, c, d is made (e). The sum (f) of the length of the second arm 303 of the robot 1, the length of the second arm 308 of the robot 2, the hand diameter 304 of the robot 1 and the hand diameter 309 of the robot 2 is computed. In the case of e>f, no interference is judged, and the authorization of action is transmitted to the robot 1. In the case of e<=f, interference is judged to exist, and the wait of action is transmitted to the robot 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a safer interference check method with less tact loss, by performing interference check between the robots when working with a plurality of robots.

[0002]

2. Description of the Related Art When performing a work operation in a region where a plurality of robots interfere with each other, it is necessary to prevent the robots from colliding with each other, and it is necessary to determine whether or not the robots interfere with each other before operating each robot. Need to check. In such a case, the following methods have been conventionally used.

The first method is a case where there is no function of automatically checking for interference, and in the creation of a program for designating a work operation procedure for each robot, interlock signals are exchanged with each other, and at the same time there is a possibility of interference. It is a method of creating a program including a procedure for waiting so that a plurality of robots do not enter a certain area.

The second method is described in Japanese Patent Application Laid-Open No. 62-159.
203), the shared work space of a plurality of robots is divided, and in which of the divided spaces the position data of the robot exists is managed, and the plurality of robots share the same space. This is a method of preventing collision between robots by not occupying space.

The third method is described in Japanese Patent Laid-Open No. 60-208.
95) and (JP-A-1-135491), it is said that the distance of the position of the hand of the robot and the vector from the tip of the arm of the robot to the tip of the arm of another robot are monitored during operation. Is the way.

[0006]

However, in the first method of the conventional example, the work operation procedure is planned so that the robots do not collide with each other by taking into consideration the postures of the arms which differ depending on the operation position in all the operation paths. Therefore, there is a problem that it takes a lot of time and effort to create a program, and there is a risk of collision between robots due to a program error.

Further, in the second method of the conventional example, for a plurality of robots having flexibility in the motion direction and motion speed,
Since it is very difficult to set which space collides with which space and which space does not collide, and it determines whether or not to interfere depending on where the other robot is. There was a problem that interference cannot be checked when the other robot is operating.

In the third method of the conventional example, there is a problem that interference other than the hand of the robot cannot be accurately detected, and a problem that calculation processing takes time because the interference is repeatedly checked during operation. there were. In addition, if the robot shape is calculated more accurately with a three-dimensional geometric model and interference is checked, the calculation processing time will become longer, and a great amount of labor will be required to input the shape model accurately. There was a problem of this.

The present invention solves the above-mentioned conventional problems, and a program can be easily created without being conscious of the operation area of a robot or an interlock, that is, without considering interference between robots. With the goal.

Another object of the present invention is to make it possible to determine whether or not the other robot will interfere in a short time even when the other robot is operating.

[0011]

In order to solve the above-mentioned problems, in the interference avoidance method for a plurality of robots according to the first aspect of the present invention, the first arm rotates about the J1 axis, and the first arm is rotated.
In a robot system in which a plurality of horizontal articulated robots in which a second arm rotates about the J2 axis at the end point of the arm are arranged so that the operation limit ranges of the J1 axes face each other, when the robot starts moving, the other robot When on the move,
Distance between the first arm end point of the movement start point of the robot and the first arm end point of the movement start point of the other robot, and the first arm end point of the movement start point of the robot and the first arm end point of the movement target point of the other robot , The distance between the first arm end point of the movement target point of the robot and the first arm end point of the movement start point of the other robot, and the first arm end point of the movement target point of the robot and the movement target point of the other robot. The process of calculating the minimum value of the four types of distances of the first arm end points, the length of the second arm of the robot, the length of the second arm of the robot, and the projection on the XY plane attached to the tip of the robot. The calculated hand diameter and the sum of the hand diameter projected onto the XY plane attached to the tip of the robot on the other hand, and the process of comparing the calculation results We are checking the interference of the robot.

Further, in the method for avoiding interference of a plurality of robots according to the second aspect of the present invention, when the robot starts moving, on the other hand, when the robot is stopped, the first arm end point of the robot starting point and the other end The process of calculating the minimum value of the distance between the first arm end point of the robot, the distance between the first arm end point of the movement target point of the robot and the first arm end point of the other robot, and the length of the second arm of the robot. The process of calculating the sum of the length of the second arm of the robot on the other hand, the diameter of the hand projected on the XY plane attached to the tip of the robot, and the diameter of the hand projected on the XY plane attached to the tip of the other robot is compared with the calculation result. Through the process, interference with the other robot is checked when the robot moves.

Further, in the robot interference avoidance method of the present invention, the two interference check methods are selected and executed according to whether the robot is moving or stopped at the start of movement of the robot. This is to check the interference with the other robot when the robot moves.

[0014]

The function of this technical means is as follows.

A plurality of horizontal articulated robots in which the first arm swings around the JI axis and the second arm swings around the J2 axis at the end point of the first arm are set within the movement limit range of each J1 axis. In the robot systems arranged facing each other, the operation area of the robot is determined by the start position and the operation target position, and the J2 axis of each robot comes closest to the operation start position or the target position. Therefore, considering the possibility that there is a turning delay of the second arm, whether or not each robot interferes with the motion is determined by the second position of each robot at two points of the motion start position and the motion target position of each robot. If the sum of the arm length and the radius of the hand attached to the tip of the second arm is smaller than the distance between the end points of the first arms of the robots, it can be determined that they do not interfere with each other.

This determination is performed at the start of each operation of the robot. If the determination result is "no interference", the operation is started, and if not, the operation start is waited to avoid the robot interference. .

According to this method, the calculation processing time at the time of executing the operation robot work is relatively short, and the load on the CPU of the control device for executing this is small. In addition, there are few numerical data required for the calculation, and it is not necessary to enter special data for the interference check. Further, even when the other robot is operating with respect to the robot performing the operation, it is possible to surely check the interference including the delay in following the operation.

That is, in order to avoid the interference of the multi-arm robot, the user needs only to determine the shape of the hand attached to the tip of the arm of the robot, specifically, the radius of the hand around the tip of the second arm. By inputting as a parameter, even if the relative position change of the first arm and the second arm occurs during the movement due to the change of the robot load or the moving speed, the interference check can be correctly judged. is there.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to the drawings.

FIG. 3 is a block diagram of the system in the embodiment of the present invention. In FIG. 3, 101 is a robot 1, 1
Reference numeral 02 is a robot 2, 103 is a controller of the robot 1, 1
Reference numeral 04 is a control device for the robot 2, and 105 is an interference determination device.

FIG. 4 is an explanatory view of the robot. As shown in FIG. 4A, each robot is a horizontal articulated robot supported from above, and the first arm 30 is centered on the J1 axis.
2 is swung by the J1 drive motor 312, and the second arm 303 is swung by the J2 drive motor 313 about the J2 axis at the tip of the first arm. As shown in FIG. 4B, the movable range of the first arm is J of the other robot.
It is limited to the range on the side 305 opposite to the one axis, and the operable range of the second arm is limited to the range 311 on the side opposite to the extension of the first arm, that is, the region passing below the first arm. . Therefore, in FIG. 4B, when the hand position at the tip of the second arm is moved from the point P to the point Q, the robot operates along the operation path indicated by the broken line.

The control device of each robot stores a program described by a dedicated command in the memory and executes it in the CPU to cause the robot to perform a predetermined work. When the command is a robot motion command, the coordinates of the movement start point and the movement target point are transmitted to the interference determination device, and the operation permission is waited for. When the operation permission is received, the operation pulse is output to the motor of each axis of the robot to operate the robot. The interference determination device performs the process of the flowchart shown in FIG. 2 to determine the presence or absence of interference. Only when there is no interference, the operation permission is transmitted to each control device. In addition,
The arm length and the hand radius of each robot are stored in the memory in the interference determination device by inputting settings from the operation device 106 in advance.

FIG. 2 is a flow chart showing an example of the method of the present invention. The flowchart of FIG. 2 will be described below with reference to the layout diagram of the robot according to the present invention of FIG.
In FIG. 1, 301 is the robot 1, 302 is the first arm of the robot 1, 303 is the second arm of the robot 1, 3
04 is the diameter of the hand attached to the tip of the robot 1, 305
Is the movement limit range of the J1 axis of the robot 1, 306 is the robot 2, 307 is the first arm of the robot 2, 308 is the second arm of the robot 2, 309 is the diameter of the hand attached to the tip of the robot 2, 310 is the robot 2 This is the operation limit range of the J1 axis.

In the following, in order to make the explanation easy to understand,
It is assumed that the robot 1 tries to move from the point A to the point B while the robot 2 is stopped at the point C in FIG. 1 or moving from the point C to the point D.

(Process 201) The coordinates of the movement start point and the movement target point are received from the control device of the robot 1.

(Process 202) If the robot 2 is stopped, the process proceeds to step 203, and if the robot 2 is operating, the process proceeds to step 208.

(Processing 203) The distance g between the first arm end point of the robot 1 at point A and the first arm end point of the robot 2 at point C.
To calculate.

(Processing 204) Distance h between the first arm end point of the robot 1 at point B and the first arm end point of the robot 2 at point C
To calculate.

(Process 205) The smaller value of g and h is i
And (Process 206) The sum f of the length H of the second arm of the robot 1, the length J of the second arm of the robot 2, the diameter I of the hand attached to the tip of the robot 1 and the diameter K of the hand attached to the tip of the robot 2 is calculated. To do.

(Processing 207) i and f are compared, and if i> f, it is determined that there is no interference and the process proceeds to step 215. Since i ≦ f, it is determined that there is interference and the process proceeds to process 216.

(Process 208) The distance a between the first arm end point of the robot 1 at point A and the first arm end point of the robot 2 at point C
To calculate.

(Process 209) The distance b between the first arm end point of the robot 1 at the point A and the first arm end point of the robot 2 at the point D
To calculate.

(Process 210) The distance c between the first arm end point of the robot 1 at point B and the first arm end point of the robot 2 at point C
To calculate.

(Processing 211) Distance d between the first arm end point of the robot 1 at point B and the first arm end point of the robot 2 at point D
To calculate.

(Processing 212) The minimum value is discriminated from among a, b, c and d, and the value is designated as e. (Process 213) The sum f of the length H of the second arm of the robot 1, the length J of the second arm of the robot 2, the diameter I of the hand attached to the tip of the robot 1 and the diameter K of the hand attached to the tip of the robot 2 is calculated. To do.

(Processing 214) E and f are compared. If e> f, it is judged that there is no interference and the process proceeds to step 215. If e ≦ f, it is judged that there is interference and the process proceeds to process 216.

(Process 215) The operation permission is transmitted to the control device of the robot 1, and the process is terminated. (Process 216) A wait for operation is transmitted to the control device of the robot 1 to end the process.

In the above example, the description was given when the operation of the robot 1 was started. However, when the operation of the robot 2 is started, the interference check can be performed by the process in which the robot 1 and the robot 2 in the above example are replaced.

By performing the above-mentioned processing for each operation of each robot, it is possible to reliably determine the interference in a short time, and it is possible to execute the work of a plurality of robots while avoiding the interference based on the determination.

[0040]

According to the method for avoiding interference of a plurality of robots of the present invention, it is possible to avoid the interference of a robot in which the calculation processing time at the time of performing the operation robot work is relatively short, and the load of the CPU of the control device for executing the operation is small. It will be possible. In addition, there are few numerical data required for the calculation, and it is not necessary to enter special data for the interference check. Further, even when the other robot is operating with respect to the robot performing the operation, it is possible to reliably check the interference including the delay in following the operation.

[Brief description of drawings]

FIG. 1 is a layout diagram of robots in an interference avoidance method for a plurality of robots according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an example of the method of the present invention.

FIG. 3 is a configuration diagram of a system according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a robot according to an embodiment of the present invention.

[Explanation of symbols]

 101 robot 1 102 robot 2 103 control device for robot 1 104 control device for robot 2 105 interference determination device 106 operating device

Claims (3)

[Claims] 1. A plurality of horizontal articulated robots in which a first arm rotates about a J1 axis and a second arm rotates about an end point of the first arm, and a plurality of horizontal articulated robots are restricted in operation of each J1 axis. In the robot system in which the ranges are arranged opposite to each other, when the robot starts moving, the other robot is moving, the first arm end point of the moving start point of the robot and the first arm end point of the other robot start point of movement. Distance, distance between the first arm end point of the movement start point of the robot and the first arm end point of the movement target point of the other robot, first arm end point of the movement target point of the robot and the first arm of the movement start point of the other robot The process of calculating the minimum value of the four types of distances, the distance between the end points, the first arm end point of the movement target point of the robot and the distance between the first arm end point of the movement target point of the other robot, and The sum of the length of the second arm, the length of the second arm of the other robot, the diameter of the hand projected onto the XY plane attached to the tip of the robot, and the diameter of the hand projected onto the XY plane attached to the tip of the other robot is calculated. An interference avoidance method for a plurality of robots, characterized in that the interference with the other robot during movement of the robot is checked by the step and the step of comparing the calculation results. 2. A plurality of horizontal articulated robots in which a first arm rotates about a J1 axis and a second arm rotates about an end point of the first arm, and a plurality of horizontal articulated robots are restricted in operation of each J1 axis. In a robot system in which the ranges are arranged to face each other, when the robot starts moving, and the other robot is stopped, the distance between the first arm end point of the moving start point of the robot and the first arm end point of the other robot, The process of calculating the minimum value of the two types of distances between the first arm end point of the robot movement target point and the first arm end point of the other robot, the length of the second arm of the robot, and the second arm of the other robot. Calculating the sum of the length of the arm, the diameter of the hand projected on the XY plane attached to the tip of the robot, and the diameter of the hand projected on the XY plane attached to the tip of the robot; A method for avoiding interference between a plurality of robots, which comprises checking interference with another robot when the robot is moving in a process of comparing the results. 3. A plurality of horizontal articulated robots in which a first arm pivots about a J1 axis and a second arm pivots about a J2 axis at an end point of the first arm, and the movement limit of each J1 axis is set. In a robot system in which the ranges are arranged to face each other, when the robot starts moving, and the other robot is stopped, the distance between the first arm end point of the moving start point of the robot and the first arm end point of the other robot, The process of calculating the minimum value of the two types of distances between the first arm end point of the robot movement target point and the first arm end point of the other robot, the length of the second arm of the robot, and the second arm of the other robot. Calculating the sum of the length of the arm, the diameter of the hand projected on the XY plane attached to the tip of the robot, and the diameter of the hand projected on the XY plane attached to the tip of the robot; In the process of comparing the results, the interference with the other robot during movement of the robot is checked,
At the start of the movement of the robot, when the other robot is moving, the distance between the first arm end point of the movement start point of the robot and the first arm end point of the movement start point of the other robot, the first movement start point of the robot. The distance between the arm end point and the first arm end point of the movement target point of the other robot, the distance between the first arm end point of the movement target point of the robot and the first arm end point of the movement start point of the other robot, and the movement target point of the robot. The process of calculating the minimum value of the four types of distances of the first arm end point and the distance of the first arm end point of the movement target point of the other robot, the length of the second arm of the robot, and the second arm of the other robot. Calculating the sum of the length, the hand diameter projected onto the XY plane attached to the tip of the robot, and the hand diameter projected onto the XY plane attached to the other tip of the robot; The process of comparing the interference avoidance method for multiple robots, characterized in that to check the interference between the other robots at the time of movement of the robot.