JP3783253B2 - Tuning control method for multiple robots - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a synchronization control method for a plurality of robots, for example, a control method for synchronizing an unloader robot and a loader robot in a system for handling a workpiece by a plurality of robots.
[0002]
[Prior art]
FIG. 6 is an example of a handling system. The figure shows a system in which robots 1 to 3 are installed between work stations ST1 to ST4 and perform work and handling of workpieces. In other words, the work in the work station ST1 is a system in which some work is performed at each station, and the work link is reached by the robots 1 to 3 to the work station ST4.
The work station ST2 will be described. A work that has been finished is unloaded by the robot 2 (unloader robot), and then a new unmachined work is loaded by the robot 1 (loader robot). The work station ST3 will be described. A work that has been finished is unloaded by the robot 3 (unloader robot), and then a new unmachined work is loaded by the robot 2 (loader robot).
Note that the loader robot and the unloader robot are relative to each other, and the loader robot and the unloader robot can also be operated by a single unit.
[0003]
Conventionally, in such a system, as shown in FIG. 5, in the control device of the unloader robot, an interference check is performed to determine whether the unloader robot is in a fixed interference area, and when the unloader robot escapes outside the area, By issuing an interlock release signal to the loader robot, the loader robot enters the station or sets a timer in synchronization with the unloader robot so that the loader robot enters the station after a certain period of time. I was doing it.
[0004]
[Problems to be solved by the invention]
For this reason, from the viewpoint of safety, the distance between the unloader robot and the loader robot cannot be shortened, or the waiting time is longer than necessary, and there is a drawback that it takes more tact time than necessary.
On the other hand, the present applicant has proposed a technique disclosed in Japanese Patent Laid-Open No. 7-1060 as a robot system synchronized with a press machine. However, there is a drawback that an encoder device (press position detector) attached to a press machine is necessary, and it cannot be applied to a system that does not have such a machine and includes only a robot.
Accordingly, an object of the present invention is to provide an apparatus that can shorten the distance between the unloader robot and the loader robot and can shorten the tact time.
[0005]
[Means for Solving the Problems]
The present invention, each with a plurality of drive shafts, made in the tuning control method for a three or more multiple robots made of the same axis configuration, and the tuning robot as a master, a slave with respect to the object to be tuned robot tuning At least one robot having a pair of robots sandwiched between different robots on both sides is set to serve as a tuning robot for one side of the robot and a robot to be tuned for the other side of the robot, after no cascaded by connecting the output of the rotation detector attached to a predetermined drive shaft of the tuning robot to the control device of each of the tuning robot, first teaching the operation of the object to be tuned robot, followed wherein the motion path of the tuning robot, for each position the number of output pulses from the rotation detector becomes a plurality of predetermined value each, said predetermined value And teaching the operating positions of the corresponding tuning robot, further wherein an output pulse from said rotation detector attached to the predetermined driving shaft of the tuning robot, the operating position of said tuning robot is teaching correspondingly The tuning robot is stored in the control device of the tuning robot, and in the actual work, the tuning robot is instructed according to the output pulse number according to the number of output pulses according to the correspondence table. the is characterized in that to follow-up operation with respect to the object to be tuned robot.
[0006]
[Action]
The rotation detector attached to the drive motor of any one of the drive axes of the robot to be tuned is inherently possessed by the robot, and the signal of this detector is sent to the command of the other robot. The point of the present invention is to divert it. In other words, while checking the actual operation of the tuning side of the robot at predetermined pulse intervals, the tuning side of the robot keep teaching so as not to interfere with the tuning side of the robot. The tuning by issuing a position command for each predetermined interval either in correspondence with the output pulses of the attached rotation detector to the driving motor 1 axis tuning-side robot of the drive shaft of the tuning-side robot (Follow-up) control.
[0007]
【Example】
Hereinafter, a case where the embodiment of the present invention is applied to the system of FIG. 6 shown as a conventional example will be described as an example. In the present invention, attention is paid to the drive shaft that moves most greatly in actual work. In the example of FIG. 6, the first axis moves the most (must be rotated 180 ° for workpiece transfer). Therefore, there are in Figure 2 (A) to that shown unloader robot (the tuning robot, master) and the number of output pulses rotation detector of the first axis, the loader robot (tuning robot, a slave-side) the distance between the . FIG. 2B shows the positional relationship. If the unloader robot can be transported only by rotating the first axis, it becomes a sinusoidal curve as shown by the dotted line in FIG. 2 (A). However, there is actually an obstacle, and the transport is performed by the link operation of all axes of the robot. Therefore, the curve is often a solid line as shown in FIG. In the present invention, first, the entire operation path is taught by teaching several operation points of the operation position of the unloader robot. Then, the number of output pulses of the rotation detector of the first axis is divided and stored at appropriate pulse number intervals as shown in FIG. That is, it is stored as a broken line approximation.
[0008]
Next, the movement is stopped at every pulse number interval, and the playback operation of the unloader robot is performed. The position of the loader robot is taught with respect to the position of the unloader robot at every pulse number interval. Considering the position of the unloader robot moving in the direction of removing the workpiece from the work station, the operator determines how far the arm of the loader robot can move toward the work station and teaches. As described above, the position where the loader robot should move is determined in accordance with the number of output pulses of the rotation detector of the first axis of the unloader robot. That is, a correspondence table such as the position P1 at the first 400th pulse, the position P2 at the 700th pulse, the position P3 at the 1200th pulse, etc. can be created (see FIG. 4). The dotted line portion in FIG. 4 is added to explain the relationship with FIG.
[0009]
If the number of output pulses of the rotation detector for the first axis of the unloader robot and the position to which the loader robot should move can be determined, the number of output pulses of the rotation detector for the first axis of the unloader robot reaches a predetermined number. If a command to move to the corresponding teaching position is transmitted to the loader robot, the loader robot can operate without interfering with the unloader robot. Therefore, in order to achieve this, a pulse is received from the first axis of the unloader robot in the loader robot control device, and if the pulse reaches a predetermined integrated amount, a command for operating to a previously associated position is issued. What is necessary is just to add a means.
[0010]
In order to implement this, the correspondence table is stored in a memory in the loader robot control device. The block diagram is shown in FIG. The output pulse of the rotation detector of the first axis of the robot 3 is input to the control device 2C of the robot 2, the corresponding teaching position is output from the correspondence table to the operation command unit, and the robot 2 operates. The output pulse of the rotation detector of the first axis of the robot 2 is input to the control device 1C of the robot 1, the corresponding teaching position is output from the correspondence table to the operation command unit, and the robot 1 operates. In this way, it operates in a chain reaction manner. The loader robot starts to move after the number of output pulses of the rotation detector of the first axis of the unloader robot reaches a predetermined number . However, if the high-speed operation is performed, it follows with a slight delay, and in handling work, it can be realized that all the robots are operating synchronously.
[0011]
【The invention's effect】
As described above, according to the present invention, the operation that does not interfere with each other at each point position is taught in advance, and the follow-up control is performed by using the output pulse of any one axis of the robot as the master. It is also possible to greatly reduce the tact time because it is possible to perform synchronous control of extremely mixed operations of a plurality of robots. In addition, since highly interlaced operations can be synchronized, the installation interval between robots can be short, which contributes to space saving. Further, in the case of synchronization of three or more units, it is basically the same as the case of two units, and any number of necessary units can be linked, and there is an effect that it is possible to easily cope with increase / decrease of facilities.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is an operation explanatory diagram of the present invention. FIG. 3 is an operation explanatory diagram of the present invention. Diagram showing an example [Fig. 6] Diagram showing a configuration example of a handling system [Explanation of symbols]
1, 2, 3 ... Robots ST1, ST2, ST3 ... Work stations 1C, 2C, 3C ... Robot controller

Claims (2)

In a synchronous control method for three or more robots each having a plurality of drive axes and having the same axis configuration,
And the tuning robot as a master, the pair of sets of tuning a robot as a slave with respect to the tuning robot, at least one robot was flanked on another robot, tuning robot for one side of the robot And the robot to be tuned to the robot on the other side,
After connecting the output of the rotation detector attached to the predetermined drive shaft of the tuned robot to the control device of each of the tuned robots and making a cascade connection,
First, the teaching operation of the object to be tuned robot,
Subsequently, in the path of motion of the object to be tuned robot, for each position the number of output pulses from the rotation detector becomes a plurality of predetermined values, and teaching the operation position of the tuning robot corresponding to the predetermined value,
Further, a control table for controlling the tuning robot includes a correspondence table composed of a combination of an output pulse from the rotation detector attached to a predetermined drive shaft of the robot to be tuned and an operation position of the tuning robot taught correspondingly. Memorize in the device,
Actual work time, according to the correspondence table, a plurality, characterized in that to follow operating the tuning robot relative to the object to be tuned robot by commanding the operation position with respect to the tuning robot according to the number of output pulses Robot tuning control method. The method according to claim 1, wherein the predetermined drive axis of the robot to be tuned is a drive axis having the largest movement amount in the teaching operation.

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