JPH0596481A - Robot control device - Google Patents

Abstract

PURPOSE:To provide a control system for a robot external control shaft wherein general usability of a teaching program can be contrived while simplifying and facilitating teaching. CONSTITUTION:In an external control shaft controlled synchronously with a robot manipulator, a position at the point of time of starting creation of a program by teaching serves as the reference position (step 1), and each teaching point successively taught corresponding to action is stored (step 4) by a relative position data form from the reference position to perform relative moving successively to the teaching point with a point of time of starting execution serving as the reference position in playback action of this program.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial robot controller, and more particularly to a teaching / playback control system for an external control axis which is controlled in synchronization with a robot manipulator.

[0002]

2. Description of the Related Art In a teaching / playback type robot, teaching data stored during teaching is an absolute angle or absolute position with respect to a reference position peculiar to the robot. Then, at the time of playback, no matter which angle or position the operation is started, it rotates and moves according to the taught absolute value. This idea also applies to an external control axis that is controlled in synchronization with the robot manipulator, and there is an origin related to the external control axis, and the absolute control is performed based on the origin.

As described above, in the teaching / playback type robot and the external control axis which are controlled by the absolute position, the operation program corresponds to the target work 1: 1 and when the work is changed. Needs to change the operation program each time.

FIG. 1 shows an example of welding work using a robot and an external control axis. Specifically, it is a work for welding a plurality of ribs 2 arranged on a long flat plate 1 at equal intervals. Is provided with a traveling carriage 3, and a robot manipulator 4 is mounted on the traveling carriage 3. Then, in order to sequentially weld the welding points W1 to W5 of the flat plate 1 and the five ribs 2, positioning is performed in the longitudinal direction on the traveling axis (external control axis), and then the robot manipulator 4 on the traveling carriage 3 is used. It is necessary to teach and play back a series of operations for welding work. Thus, conventionally, the traveling axis has been controlled by the absolute position.

[0005]

However, the conventional system for controlling the traveling axis by the absolute position has the following problems.

(1) The welding operation itself by the robot manipulator is exactly the same operation, but since the position of the traveling axis is different, it is necessary to teach all the welding points continuously from the beginning, and the number of man-hours is enormous. As a result, it is inefficient in high-mix low-volume production.

(2) When the rib pitch is changed, it becomes necessary to redo teaching entirely.
Lack of versatility and flexibility.

(3) A system in which the position of the rib is detected by using a sensor and the traveling shaft is positioned by a sensor detection signal cannot be realized by a method of treating the traveling shaft position as an absolute position.

As described above, there is an inconvenience that the teaching / playback method of controlling the external control axis which is controlled by the absolute position cannot be quickly handled depending on the application.

The present invention is intended to solve these problems, and to provide a control system for an external control axis, which facilitates and simplifies teaching, reduces man-hours, and allows versatility of programs. The purpose is.

[0011]

In order to achieve the above object, a robot controller according to the present invention comprises an external control axis which is controlled in synchronization with a robot manipulator, and an external control for performing teaching / playback. As the axis motion control method, in teaching a program for performing a series of operations, the position data of the external control axis at the start of program creation is initialized as the reference position, and the program is taught sequentially in accordance with the operation. Each teaching point is stored in the teaching data storage unit in the form of relative position data from the reference position, and in the playback operation of the program, the position data of the external control axis at the start of execution of the program is used as the reference position. As a relative position data format in the teaching data storage section by the teaching. Sequentially reads the teaching point data being paid, and performs relative movement by running sequential movement control to the teaching point of the program with respect to a reference position at the time of the playback.

[0012]

According to the operation control system of the external control axis of the present invention, the teaching point data of the taught program is the relative position data based on the teaching start time, and the execution start time is used in the playback operation of this program. It operates according to the teaching data with reference to.

Thus, the external control axis can teach a series of operations from an arbitrary position, and a playback operation corresponding to teaching data can be performed at an arbitrary position.

That is, in the case of the example shown in FIG. 1, the operation of the robot manipulator 4 for welding one rib 2 is taught, and the rib is set for the traveling axis (external control axis). By simply teaching only the operation of moving between two pitches of 2, it is possible to cope with all welding points by repeatedly executing these two types of programs as necessary. More specifically, the movement between the pitches of the rib 2 by the traveling axis and the welding work by the robot manipulator are independently performed by the relative movement. When the distance between pitches is changed, only a part of the traveling movement program is changed and it does not affect the whole. Further, even when the change in the distance between the pitches is dealt with by the traveling axis positioning using the sensor, the welding work program is executed at the positioning stop position and the operation can be realized.

[0015]

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

FIG. 1 shows an example of an actual work, in which a traveling carriage 3 is used as an external control axis for a rib 2 arranged on a flat plate 1, a robot manipulator 4 is mounted thereon, and welding points W1 to W5 are provided. It is a structure for welding.

FIG. 2 is a block diagram showing a schematic configuration of a system including a robot and an external control axis. The operation of the robot manipulator 11 and the external control axis 12 is controlled by a robot controller 5, and the robot controller 5 is composed of an operating unit 6, a main controller 7, a servo controller 8, and a drive unit 10. . Also, the robot controller 5
Is equipped with a teach pendant for performing operations such as teaching.

FIG. 3 shows the basic structure of the control unit, and the RO is mainly the CPU 13 and has the control software built-in.
M14, teaching data storage unit 15 for storing taught data, work RAM 1 used for work of various processes
6 and a part of the work RAM includes an offset area 17 and a movement command area 18, which will be described later. It also has a position counter 19 for counting and displaying the positions of the robot manipulator and the external control axis.

Next, the method of the present invention will be described in detail with reference to the flow charts of FIGS. 4 and 5.

FIG. 4 shows the procedure of teaching data generation processing for the external control axis during teaching. Step 1 at the start of program creation by teaching
Thus, the content of the position counter 19 is stored in the offset area 17 as an offset. Next, when the external control axis is moved (step 2) and registered (step 3), position counter content-offset content is calculated in step 4 and stored in the teaching data storage section 15 as teaching data of the external control axis. The procedure of steps 2, 3 and 4 is repeated until the end (step 5) operation is performed on the teaching points sequentially taught corresponding to the required motion. The teaching data of the external control axis of the program created in this way is relative position data with the program creation start time being zero.

FIG. 5 shows a processing procedure for an external control axis in playback according to the present invention. At step 11 when the program is started to be played back, the data in the movement command area 18 is cleared to zero. The data in the movement command area 18 indicates the amount to be moved during playback. Next, the teaching data is read (step 12), the movement command + teaching data is calculated in step 13, and the calculated data is used in step 14
Is executed, the teaching data of the program to be played back is sequentially read, and the above process is repeated until the end of the program. In this way, the control of the external control axis in playback is performed based on the relative movement command with the program execution start time set to zero.

As is clear from the configuration shown in FIG. 3, the present invention uses the control software stored in the ROM 14 to control the C
It is realized by execution by the PU 13.

[0023]

As described above, in the operation control system of the external control axis according to the present invention, the teaching point data of the taught program is the relative position data based on the teaching start point, and the playback of this program is performed. The operation is a relative movement according to the teaching data with reference to the execution start time. As a result, the external control axis can teach a required series of operations from an arbitrary position, and a required playback operation can be performed at an arbitrary position.

As a result, in the case where the same operation is carried out only with the positional relationship of the external control axes being different, the teaching operation is continuously performed from the beginning as compared with the conventional method in which the operation control is performed at the absolute position. There is no need to do so, and the man-hours can be greatly reduced. In addition, the teaching correction and the like accompanying the change of the member are also simplified, and the created program is highly versatile.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of welding work using a robot and an external control axis.

FIG. 2 is a block diagram showing a schematic configuration of a system including a robot and an external control axis according to an embodiment of the present invention.

FIG. 3 is a basic configuration diagram of a control unit in the robot control device.

FIG. 4 is a flow chart showing a control method during the teaching.

FIG. 5 is a flowchart showing a control system during the playback.

[Explanation of symbols]

 1 Flat Plate 2 Rib 3 Travel Carriage 4, 11 Robot Manipulator 5 Robot Control Device 6 Operating Unit 7 Main Control Unit 8 Servo Control Unit 9 Teach Pendant 10 Drive Unit 12 External Control Axis 13 CPU 14 ROM 15 Teaching Data Storage Unit 16 Work RAM 17 Offset 18 Movement command 19 Position counter

Claims (1)

[Claims] 1. A robot having an external control axis that is controlled in synchronization with a robot manipulator and performing a series of operations as a nuclear external control axis operation control method in a robot performing teaching / playback. Teaching initializes the position data of the external control axis at the start of creating the program as a reference position, and teaches each teaching point in the program sequentially corresponding to the operation in the form of relative position data from the reference position. On the other hand, the playback operation of the program is initialized by using the position data of the external control axis at the start of execution of the program as a reference position,
The teaching point data stored in the teaching data storage unit in the relative position data format is sequentially read by the teaching, and relative movement is performed by sequentially moving control to the teaching point of the program with respect to the reference position at the time of playback. Robot controller with the function to perform.