JPH03181367A - Method for returning robot to original position - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a method for returning a robot to its original position, which automatically returns a robot operating according to a pre-taught operating procedure to its original position when an abnormality occurs. Regarding the method.

[Prior Art] Industrial robots are widely used to automatically carry out workpiece transport, welding, painting, etc. This type of robot is usually configured to perform a predetermined task according to operating procedures stored in a robot controller through direct instruction.

In this case, an abnormality may occur in a robot that is executing a predetermined teaching operation, or a robot that is performing another task in conjunction with this robot, and the operation of the robot may stop. At this time, in order to return the stopped robot to its original position, the following two methods have been conventionally used.

The first method is to switch the robot from the teaching mode to the manual mode, and have the operator directly operate the robot to return it to its original position without interfering with the workpiece or other robots.

The second method is to constantly send the robot's position to the robot controller using an encoder, etc., and determine the relative position of the robot and the workpiece and the shape of the workpiece when an abnormality occurs, and interfere with the workpiece. This method automatically returns the robot to its original position by calculating a return route that will not occur.

[Problems to be Solved by the Invention] However, the first method, which relies on the worker's own manual work, increases the burden on the worker and is particularly difficult when returning a large number of robots to their original positions. It has been pointed out that the drawback is that it requires a lot of effort. On the other hand, the second method of calculating the return route requires a huge amount of data, and moreover, the robot controller must perform complicated data processing.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for returning a robot to its original position, which makes it possible to automatically and efficiently return a robot in the middle of a predetermined teaching operation to its original position without performing complicated data processing. It's about doing.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention sends a home position return signal to a controller that operates a robot to perform work along a work trajectory taught in advance. a step of moving the robot further along the work trajectory from the time when the home position return signal is sent to a predetermined branch point; and a step of moving the robot between the branch point and the home position. a step of moving the device to the original position along a return trajectory predetermined between the two locations.

[Operation] In the method for returning to the original position of a robot according to the present invention, a predetermined number of branch points are provided on the work trajectory taught in advance, and therefore, after the return to original position signal is sent, the robot returns to its original position. When the robot moves to the branch point, the robot automatically moves along a predetermined return trajectory between the branch point and the original position. This eliminates the need for complicated data processing in the controller, and allows the robot to move to its original position along a predetermined return trajectory in a short time.

[Example] A method for returning a robot to its original position according to the present invention will be described in detail below by giving an example and referring to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates an automatic painting device for carrying out the method for returning a robot to its original position according to this embodiment, and the automatic painting device 10 is connected to a robot controller 12.
and a painting robot 14 which is a non-contact type robot.

The robot controller 12 controls the painting robot 14 taught via the teaching box 16 as described later.
It stores the operating procedure and the return trajectory from a predetermined branch point to the original position, and is connected to the mask controller 18. This mask controller 18 sends an original position return signal Sa to a predetermined robot controller (not shown) in addition to the robot controller 12.

The painting robot 14 is a known articulated robot,
It is configured to perform painting work on the workpiece W via a painting gun 22 attached to the wrist portion 20.

The automatic painting apparatus according to this embodiment is basically constructed as described above, and its operation will be explained next.

First, as shown in FIG.
The work of teaching the working locus and return locus of the painting gun 22 constituting the painting robot 14 is performed via the painting robot 14.

That is, the coordinates of nine teaching points P1 to P9 from the original position PO are stored in the robot controller 12 by operating the teaching box 16, and the working trajectory 24 is created by hitting each teaching point P1 to P9 from the original position PO. is set. Furthermore, other painting conditions such as paint injection commands between the teaching points P1 and 26 are determined by the robot controller 12.
is memorized.

Among teaching points Pl to P9, teaching points P3 and P4 are set as branch points TI and T2, respectively, and from the branch point Tl to a via point A
A first return trajectory 26 that reaches the original position PO via
The return trajectory 28 is stored in the robot controller 12. The first return trajectory 26 and the second return trajectory 28 are set so that the painting robot 14 can return from the respective branch points T1 and T2 to the home position PO without interfering with the workpiece W and in the shortest possible time. ing.

Therefore, the procedure for painting the workpiece W using the painting gun 22 and returning the painting gun 22 to the original position PO is explained in the third section.
This will be explained below with reference to the flowchart shown in the figure.

In the robot controller 12, when the teaching data is read from the memory (STPI), an operation signal according to this teaching data is sent to the painting robot 14 (Sr
F2). Therefore, the painting robot 14 is driven, the painting gun 22 moves from the original position PO along the working trajectory 24, and painting work on the workpiece W is started.

During the painting operation by the painting gun 22, if the original position return signal Sa is not sent from the mask controller 18 (SrF3), the painting operation by the painting gun 22 is continued and the teaching point P9 reaches the original position PO. The painting work on the workpiece W is completed (SrF4).

If the painting gun 22 stops at a point E between the teaching points P2 and P3, or if an abnormality occurs in another robot when the painting gun 22 reaches the point E, the mask controller 1
Return to original position signal Sa from 8 to robot controller 12
will be sent.

The painting gun 22 further moves along the working trajectory 24,
When reaching the teaching point P3, that is, the branching point T1, (SrF2
), and the original position return signal Sa is sent to the robot controller 12, so that predetermined return data from this branch point T1 to the original position PQ is sent within the robot controller 12 (SrF2). Therefore, paint gun 2
2 moves along a first return trajectory 26 from the branch point T1 to the original position Pal via the via point A. Here, the coating gun 22 moves to the original position PQ while stopping spraying paint from when the original position return signal Sa is sent.

On the other hand, if the home position return signal Sa is sent to the robot controller 12 while the painting gun 22 is between the teaching points P3 and P4, the painting gun 22 stops ejecting paint and moves to the teaching point P4. , that is, the branch point T2 is reached. Next, the coating gun 22 moves to the original position PO along a second return trajectory 28 from the branch point T2 via the via point A to the original position PO.

As described above, in this embodiment, when an abnormality occurs during painting work, the painting gun 22 is moved along the work trajectory 24 to a predetermined branch point Tl (or T2), and then this branch point Tl ( Alternatively, it automatically moves from T2) to the original position PO via a predetermined first return trajectory 26 (or second return trajectory 28). Therefore, the coating gun 22 can be moved to the original position PO in a short time without interfering with the workpiece W. In particular, paint gun 22
Unlike the method of detecting the relative position between the paint gun 22 and the workpiece W and calculating the return route to the original position PO according to the stop position of the painting gun 22, there is no need to perform complicated data processing. Moreover, when a large number of robot devices are provided in addition to the automatic painting device 10, it is only necessary to send the original position return signal Sa from the mask controller 18 to each robot controller 12, etc. . As a result, it is possible to reduce the burden on the worker at once, and to carry out the work of returning to the original position efficiently.

[Effects of the Invention] As described above, the method for returning a robot to its original position according to the present invention has the following effects and advantages.

By simply setting a branch point at a predetermined position on the work trajectory taught in advance and determining a return trajectory from this branch point to the original position, the system can be used without any complicated data processing.
The robot can be automatically and efficiently moved to this original position.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram of an automatic painting device for carrying out the method of returning a robot to its original position according to the present invention; Fig. 2 is an explanatory diagram of the teaching work of the work trajectory and the return trajectory; It is a flowchart which shows the procedure of the method of returning a robot to its original position. 10...Automatic painting device 12...Robot controller 14...Painting robot 18...Mask controller 22...Painting gun Sa...Original position return signal FIG, 1

Claims (1)

[Claims] (1) A process of sending a return-to-home signal to a controller that operates the robot along a pre-taught work trajectory, and a point in time when the return-to-home signal is sent to the robot. further moving the robot along the working trajectory to a predetermined branching point; and moving the robot to the original position along a predetermined return trajectory between the branching point and the original position. A method for returning a robot to its original position, comprising: