JPH0584680A - Control device for robot - Google Patents

Abstract

PURPOSE:To prevent a contact trouble by providing an arithmetic means which can change values, stored in the second and fourth memory means, of a deceleration degree at the final acting point of a robot to calculate a desired locus when a locus of actuating the robot is calculated. CONSTITUTION:A deceleration degree is changed by the first arithmetic means 7 to calculate an acting locus in accordance with the changed deceleration degree respectively in accordance with an output of a detecting means 2 from the first memory means 3, in the case of no information at an execution starting point, and from the third memory means 5, in the case of providing information at the execution starting point, in an attribute of action of the next action interval, when an action form is PTP control. If in the case that the action form is linear interpolation in CP control, the deceleration degree is changed by the second arithmetic means 8 respectively in accordance with an output of the detecting means from the second memory means 4, in the case of no information at the execution starting point, and from the fourth memory means 6, in the case of providing information at the execution starting point, in the attribute of action of the next action interval.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot controller capable of shortening the working time of the robot in welding, cutting, polishing and the like.

[0002]

2. Description of the Related Art A conventional robot does not have a control function of automatically decelerating so as not to overshoot when approaching a construction start point. By providing a motion section that is operated and taught to reach the construction start point at a low speed, the final actuator (hereinafter simply referred to as the final actuator) such as the welding torch and tool at the construction start point and the construction object It prevented the interference of.

[0003]

Therefore, in the conventional robot, when teaching to reach the construction start point at high speed, an overshoot occurs at the teaching position of the construction start point, and the final actuator operates. There was a problem that contact or collision with the construction object occurred. In addition, if you teach the robot to approach the construction start point at a low speed, you can avoid the problem of the final actuator coming into contact with or colliding with the construction object, but it will increase the robot's work time and increase productivity. Another problem of lowering occurs.

The present invention is intended to solve the above problems, and provides a robot controller that automatically decelerates even when approaching a construction start point at a high speed so as to prevent overshoot with respect to a teaching position. The purpose is to do.

[0005]

In order to achieve the above object, a robot controller according to the present invention comprises an operation command storage means for storing information indicating an execution start point which is an attribute of the operation command. The detection means for detecting whether or not the construction start point information exists in the attribute of the operation command of the next operation section, and the degree of deceleration of each axis of the robot when the operation mode of the robot is PTP (POINT TO POINT) control The first storage means for storing the standard value and the operation mode of the robot are CP (CONT
INUOUS PATH) The second storage means for storing the standard value of the degree of deceleration of the final action point of the robot which operates while drawing a desired trajectory in the case of linear interpolation in the control, and the operation mode of the robot are the PTP control. In the case of the third storage means for storing the degree of gentle deceleration of each axis of the robot in the case of, and the final action point of the robot that operates while drawing a desired trajectory in the case where the operation form of the robot is linear interpolation in CP control. The value stored in the fourth storage means for storing the degree of gentle deceleration, the value stored in the first storage means for the degree of deceleration of each axis when calculating the motion locus of the robot, and the third storage means. The first calculation means capable of changing the value and the second storage means for storing the degree of deceleration of the final action point of the robot which operates while drawing a desired trajectory when calculating the movement trajectory of the robot are stored in the second storage means. Second calculation means for calculating a desired trajectory capable of changing the stored value and the value stored in the fourth storage means, and driving means for operating the robot according to the calculation result. It is equipped with and.

[0006]

According to the above construction, the detecting means has a function of detecting whether or not the construction start point information is present in the movement attribute of the next movement section, and the first storage means stores each robot. A standard value of the degree of deceleration of the axis is stored, a standard value of deceleration of the final action point of the robot operating while drawing a desired trajectory is stored in the second storage means, and each axis of the robot is stored in the third storage means. The degree of gentle deceleration is stored in the fourth storage means, and the degree of gentle deceleration at the final action point of the robot operating while drawing a desired trajectory is stored in the fourth storage means.

When the operation mode is PTP control, if there is no construction start point information in the attribute of the movement of the next movement section, the first storage means, and if there is construction start point information, the third storage means. From the means, the first computing means changes the degree of deceleration in accordance with the output of the detecting means, and calculates the operation locus according to the changed degree of deceleration. If the operation form is linear interpolation in CP control (hereinafter simply referred to as linear interpolation), if there is no information on the construction start point in the attribute of the movement of the next movement section, construction start from the second storage means. If there is point information, the second calculating means changes the degree of deceleration from the fourth storing means in accordance with the output of the detecting means, and calculates the operation locus according to the changed degree of deceleration. To do.

The above calculation result is output to the robot driving means, and the robot driving means operates the robot according to the calculation result. As a result, the robot gradually decelerates when approaching the construction start point, so that the drive means can reach the target position without causing the overshoot to the teaching point.

[0009]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a robot controller according to the present invention, and FIG. 2 is a block diagram showing a minimum hardware configuration for realizing the robot controller according to the present invention.

In FIG. 1, reference numeral 1 denotes an operation command storage means for storing information indicating a construction start point which is an attribute of the operation command,
2 is a detection means for detecting whether or not the construction start point information exists in the attribute of the operation command of the next operation section, and 3 is the degree of deceleration of each axis of the robot when the operation mode of the robot is PTP control. The first storage means for storing the standard value of 4 is a second storage means for storing the standard value of the degree of deceleration of the final action point of the robot that operates while drawing a desired trajectory when the operation mode of the robot is linear interpolation. Means for storing the degree of gentle deceleration of each axis of the robot when the operation mode of the robot is PTP control, and 6 is desired when the operation mode of the robot is linear interpolation Fourth storage means for storing the degree of slow deceleration of the final point of action of the robot operating while drawing the locus of, and 7 is the first storage means 3 for the degree of deceleration of each axis when calculating the movement trajectory of the robot. The value stored in The first operation means 8 is capable of changing the value stored in the storage means 5 of the robot, and 8 is for decelerating the final action point of the robot which operates while drawing a desired trajectory when calculating the operation trajectory of the robot. The second calculation means for calculating a desired locus capable of changing the value stored in the second storage means 4 and the value stored in the fourth storage means 6, Robot driving means 10 is a robot.

Further, in FIG. 2, 11 is a robot 1.
The ROM 12 for storing the control program of 0 and including the first storage means 3 and the second storage means is mainly the robot 1.
A RAM for storing the operation program of 0, a D / A converter for performing D / A conversion of the control data of the robot 10, a servo amplifier for driving each axis of the robot 10, a for controlling the entire robot system It is a CPU.

The operation will be described below with reference to FIGS. 1 and 2. First, the detection unit 2 stores in the operation command storage unit 1 that stores the construction start point command indicating the attribute of the operation command described regarding the next operation stored in the RAM 12,
It is detected whether or not there is information indicating that construction will be started from the next operation. Specifically, check whether the bit of the data indicating the construction start point is 1 or 0,
The bit indicating whether or not each arithmetic means selects the standard degree of deceleration is set to 1 or 0. In this embodiment, the bit of data is set to 1 if it is the construction start point, or 1 if the standard degree of deceleration is selected.

First storage means 3 and second storage means 4
Is an area for storing the standard value, so in this embodiment, this area is provided in the ROM 11 of FIG. In the third storage means 5 and the fourth storage means 6, the initial value is ROM1.
Although it is stored in 1, the initial value is copied to the RAM 12 because the value differs depending on the state in which the robot is used.
Thereafter, the value copied in the RAM 12 is used as a value for designating the degree of gentle deceleration.

The first computing means 7 checks the bit indicating whether or not the standard degree of deceleration should be selected when the operation mode is PTP control, and if it is 1, the first storage means 3
Therefore, if 0, a value for determining the degree of deceleration is read from the third storage means 5, and the operation for deceleration is calculated according to the value. The second computing means 8 checks the bit indicating whether or not the standard degree of deceleration should be selected when the operation mode is linear interpolation, and if it is 1, it is stored in the second storage means 4 by 0. If there is, from the fourth storage means 6,
A value for determining the degree of deceleration is read, and the operation for deceleration is calculated according to the value. The result of the calculation is output to the driving means 9, and the driving means 9 operates the robot 10 according to the command.

The above operation is realized by the CPU 15 and a program for operating the CPU 15. Drive means 9
Is a D / A converter 13 for outputting two calculation results from the CPU 15 and a servo amplifier 1 for driving a motor
It is composed of four.

FIG. 3A shows a change in speed when the vehicle is decelerated at a standard deceleration degree D1, and FIG. 3B shows a speed change when decelerated at a standard deceleration degree D2. Using FIGS. 3A and 3B, the first and second
The change in the degree of deceleration by the calculating means will be described.
The unit of D1 and D2 is m / sec ² .

The moving distance that the robot moves from the time t0 to the time t1 or t2 until the robot stops is shown in FIG.
It is assumed that (a) and (b) are equal. When the moving distance from t0 to the stop of the robot is X, X = x1 + x2 = x3 + x4 (1) holds. Here, x2 = v1 ² / (2 × D1) ··· (2) x4 = v1 ² / (2 × D2) ··· (3) Therefore, x1 = X−x2 ··· ( 4) x3 = X−x4 (5) Therefore, in the case of FIG. 3A, from t0 to x
It is necessary to decelerate after one operation, and in the case of FIG. 3B, it is required to decelerate from t0 to x2.

When the operation mode is the PTP control, the above calculation is applied to the axis having the highest angular velocity in the operation axis of the robot, and when the operation mode is the linear interpolation, the operation at the final action point of the robot is performed. By applying the above calculation, it is possible to realize the calculation of the motion locus that can optimally change the degree of deceleration.

FIG. 4 shows a flow chart of the program of the present invention executed by the CPU 15. In FIG. 4, first, the content of the information indicating the operation attribute of the operation instruction to be executed next is checked,
It is checked whether the next operating point is the construction start point (step A). If the next operating point is the construction start point (YES), R
Bit B of address A in the information exchange area with another task provided in AM 12 is set to 0 (step B). If the next operating point is not the construction start point (NO), the address A above
Bit B of 1 is set to 1. (Step C). The first calculating means 7 and the second calculating means 8 check whether or not the bit B of the address A is 0 (step D). When the bit B of the address A is 0 (YES), a deceleration variable indicating the degree of deceleration. The value of D1 indicating the standard degree of deceleration is substituted for the rate D (step E). If the bit B of the address A is 1 (NO), the value of D2 indicating the degree of gentle deceleration is substituted into the deceleration variable rate D (step F). Based on the above result, the trajectory of the robot is calculated (step G), the result of the trajectory calculation is output to the driving means 9 (step H), and optimal deceleration control of the robot is performed.

[0021]

As is apparent from the above description, according to the robot control device of the present invention, even when the final action point of the robot approaches the construction start point at high speed, It is possible to control that the final action point of the robot does not overshoot, and even if it teaches that the final action point of the robot reaches the construction start point at high speed, it may cause contact or collision between the construction object and the final actuator. It is possible to prevent serious accidents. Further, when the next operation point is not the construction start point, the operation time of the entire robot can be shortened by increasing the approaching speed, and the work efficiency of the robot can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a robot controller according to the present invention.

FIG. 2 is a block diagram showing a minimum hardware configuration for realizing the control device of the embodiment.

FIG. 3A is a speed characteristic diagram when the vehicle is decelerated at a standard deceleration degree D1, and FIG. 3B is a speed characteristic diagram when the vehicle is decelerated at a moderate deceleration degree D2.

FIG. 4 is a flowchart of an operation program of the present invention.

[Explanation of symbols]

 1 Operation Command Storage Means 2 Detecting Means 3 First Storage Means 4 Second Storage Means 5 Third Storage Means 6 Fourth Storage Means 7 First Arithmetic Means 8 Second Arithmetic Means 9 Driving Means 10 Robots

Claims (1)

[Claims] 1. A motion command storage means for storing information indicating a construction start point, which is an attribute of a motion command, and whether or not the construction start point information exists in the motion command attribute of the next motion section. Detection means, first storage means for storing a standard value of the degree of deceleration of each axis of the robot when the robot operation mode is PTP control, and the robot operation mode is linear interpolation in CP control. Second storage means for storing a standard value of the degree of deceleration of the final action point of the robot which operates while drawing a desired trajectory in a certain case, and gentle movement of each axis of the robot when the operation mode of the robot is PTP control Storage means for storing the degree of deceleration, and the degree of gentle deceleration of the final action point of the robot which operates while drawing a desired trajectory when the robot motion form is linear interpolation in CP control. And a value stored in the first storage means and a value stored in the third storage means for the degree of deceleration of each axis when the motion locus of the robot is calculated. A first computing means capable of performing
The second degree of deceleration of the final action point of the robot that operates while drawing a desired trajectory when calculating the robot trajectory
Second calculation means for calculating a desired trajectory capable of changing the value stored in the storage means of the above and the value stored in the fourth storage means, and the robot according to the calculation result. And a drive unit for operating the robot.