JPH05237781A - Robot control device - Google Patents

Abstract

PURPOSE:To provide a robot control device efficiently performing origin return actions in a short time without requiring a manual action. CONSTITUTION:A robot control device 10 is constituted of multiple shaft control units 11A, 11B, 11C, 11D driving motors M1, M2, M3, M4 required for origin return and a main control unit 12 independently controlling the shaft control units 11A-11D respectively. The parameter 'orgseq' omittably inputted with shaft symbols 'A', 'B', 'C', 'D' one by one designated in sequence of multiple robot shafts, e.g. four shafts of A, B, C, D, is defined, origin return actions of individual shafts are performed in the order of the shaft symbols of the parameter 'orgseq', and finally the origin return actions of all shafts for the omitted shaft symbols are performed. All shafts for the omitted shaft symbols as the parameter 'orgseq' are concurrently returned to origins, and origin return actions are efficiently performed in a short time without requiring a manual action.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an industrial robot.

[0002]

2. Description of the Related Art Industrial robots currently widely used have a mechanism for electrically positioning a rotary joint axis and a translation axis (hereinafter referred to as a robot axis) using a servo motor, a pulse motor or the like as a drive source. ing. Here, the rotation direction of the motor differs between the DC motor and the AC motor, but both positive (+) and negative (-) are determined from the electrical characteristics.

By the way, when the power is turned off and then turned on again, an operation called origin return is required to determine the absolute value of the current position of the robot axis. This return-to-origin operation is a movement to a fixed point that is determined in advance,
It means two operations of arranging the position data at that point. Then, this return-to-origin operation is automatically executed in sequence by the robot control device for all robot axes equipped in the robot.

As a usage pattern of the industrial robot, the power is often turned off after the user has moved the robot axis to a predetermined safe position before the end of the work day. Alternatively, when an abnormality occurs in another mechanical system, an emergency stop or power cut may be performed during the work. In such a case, it is necessary to perform the home-return operation again to restart the work. However, when the robot axes return to the home position in the order determined by the robot controller, the robot axes move to the work or other devices. There is a risk of interference and damage. Therefore, it is necessary to manually move each robot axis to retract the robot to a safe place and then perform the origin return operation.

By the way, normally, the robot axis to be retracted is the axis closest to the work, and there is often no risk of interfering with other devices other than the robot axis. Also, normally,
The direction of home return is set to the minus (-) direction,
Since the work is often performed in the plus (+) range, the direction of returning to the origin coincides with the retracting direction.

[0006]

However, in the conventional home-return operation, there is a problem that the work is troublesome because manual operation is required when the axis to be initially home-returned is not the axis to be retracted. It was Further, since the home-return operation is sequentially performed for each robot axis in a predetermined order, it takes a lot of time until the home-return operation for all the robot axes is completed, and there is a problem that the work efficiency is low. ..

The present invention has been made in view of the above problems, and the object of the present invention is to eliminate the need for manual operation.
It is to provide a robot control device that can perform an origin return operation with good efficiency.

[0008]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a plurality of axis controllers for driving a motor which requires home return, and a main controller for independently controlling these axis controllers. In a robot controller configured to include
Define a parameter configured by inputting the axis symbols sequentially assigned to the plurality of robot axes one by one, and perform the home-return operation of each robot axis in the order of the axis symbol of the parameter, and finally, The feature is that the origin return operation of all robot axes relating to the omitted axis symbol is performed.

[0009]

According to the present invention, the robot axes corresponding to the axis symbol described in the parameters are sequentially returned to their origins in the order described (for example, the order closer to the work), and then the origins of all the remaining robot axes are changed. Since the return is executed at the same time,
The robot axis can be returned to the origin efficiently in a short time without the need for manual operation.

[0010]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a perspective view of a robot equipped with a control device according to the present invention, FIG. 2 is a block diagram showing a configuration of the control device according to the present invention, and FIG. 3 is a flow chart showing a control operation of the control device.

The robot 1 shown in FIG. 1 has four axes (A, B,
Horizontal articulated robot for C and D axes (scalar robot)
The arm 2 is horizontally rotated about the A axis by the motor M1, the arm 3 is connected to the tip of the arm 2 and is horizontally rotated about the B axis by the motor M2, and the arm 3 is 3 has a shaft 4 extending vertically downward from the front end of the shaft 3, vertically moved in the C-axis direction by motors M3 and M4, and horizontally rotated about the D-axis. A chuck 5 for holding W is attached. The robot 1 is used for so-called pick-and-place work for replacing the position of the work W.

By the way, the robot 1 is provided with a robot control device 10 according to the present invention. The robot control device 10 is provided with the motor M as shown in FIG.
1, M2, M3, M4 each of a plurality of axis controller 1
1A, 11B, 11C, 11D and these controllers 11
The main controller 12 for independently controlling A to 11D is included.

When the power is turned off and then turned on again during the operation of the robot 1, the origin return operation is required as described above. However, the robot 1 according to the present embodiment.
In the above, if the shaft 4 is still lowered when the power is turned off, the shaft 4 may interfere with other equipment on the work table (not shown) when the power is turned on again.

Therefore, if the safety is ensured by first raising the C-axis and returning it to the origin, the remaining A, B, and D axes, which may not interfere with other objects, can be simultaneously returned to the origin. it can.

The control operation of the robot controller 10 will now be described with reference to FIG.

In this embodiment, the robots A, B, and
Axis symbols “A”, “B”, “C”,
"D" is attached to these axis symbols "A",
A return-to-origin parameter orgseq, which is configured by inputting "B", "C", and "D" one by one, is defined.

By the way, in the robot 1 according to the present embodiment, as described above, after the C axis is first returned to the origin, the other remaining A, B and D axes can be simultaneously returned to the origin. Therefore, the user has to set the return-to-origin parameter or
“C” is set as gseq, and this is input to the main controller 12 of the controller 10 via the interface.
Then, orgseq = “C” is stored in the memory of the main controller 12.

When the origin return operation is started, the parameter orgseq for one axis is read in the main controller 12 (step S1 in FIG. 3). In the case of the present embodiment, the axis symbol “C” is read as the parameter orgseq, and then it is determined whether or not there is an axis symbol (step S2 in FIG. 3). In this case, since the axis symbol “C” exists, the determination is YES, and then the axis symbol is determined (step S in FIG. 3).
3 to S5).

In this embodiment, the parameter orgseq = "C".
Therefore, the determination result in step S5 of FIG. 3 is YES.
Then, the origin return for the C-axis is performed (step S6 in FIG. 3), and when the C-axis (axis 4) rises and the origin return is completed (step S7 in FIG. 3), the parameters for the next one axis are set. Orgseq is read (step S1 in FIG. 3), and the presence or absence of the read parameter orgseq is determined again (step S3 in FIG. 3). In this case the parameter orgs
Since eq does not exist, the judgment result is NO, then A,
At the same time, it is judged whether or not the origin return for the B, C, and D axes is completed (steps S8 to S11 in FIG. 3).

In the present embodiment, as described above, the return-to-origin is completed only for the C axis, so only the judgment result for the C axis (the judgment result in step S10 in FIG. 3) is YE.
It becomes S, and the origin return is not performed again for the C axis. On the other hand, the determination result for the other axes A, B, D (the determination result in steps S8, S9, S11 in FIG. 3) is NO, and the origin return for these A, B, D axes is simultaneously performed. Done (steps S12-S1 of FIG. 3)
7).

When the origin return is completed for all the A, B, C and D axes, a series of origin return operations are completed (steps S18 and S19 in FIG. 3).

As described above, in this embodiment, after the C-axis close to the work W is first returned to the origin to avoid the interference with other equipment of the shaft 4, there is a risk of interference with other equipment. Since all the remaining A, B, and D axes are set to return to the origin at the same time,
Efficient A, B, in a short time without the need for manual operation
The origin of the C and D axes can be returned.

In the above embodiments, the horizontal articulated robot (scalar robot) is described in particular, but the present invention can be similarly applied to other orthogonal axis robots and vertical articulated robots. Of course.

[0025]

As is apparent from the above description, according to the present invention, a plurality of axis controllers for driving the motors which need to be returned to the origin and a main controller for independently controlling these axis controllers. In a robot controller including the above, a parameter configured by inputting axis symbols sequentially assigned to a plurality of robot axes one by one can be defined, and each robot axis is defined in the order of the axis symbol of the parameter. Since the origin return operation is performed and finally the origin return operations of all robot axes related to the omitted axis symbol are performed, it is possible to efficiently perform the origin return operation without requiring manual operation. ..

[Brief description of drawings]

FIG. 1 is a perspective view of a robot including a control device according to the present invention.

FIG. 2 is a block diagram showing a configuration of a control device according to the present invention.

FIG. 3 is a flow chart showing a control operation of the control device according to the present invention.

[Explanation of symbols]

 1 robot 10 robot controller 11 axis controller 12 main controller A to D axis symbol orgseq origin return sequence parameter

Claims (1)

[Claims] 1. A robot controller comprising a plurality of axis controllers for driving a motor that requires home return and a main controller for independently controlling these axis controllers, the robot controller comprising: Each of the robot axes has a parameter configured by optionally inputting the axis symbols sequentially attached,
A robot controller, wherein the origin return operation of each robot axis is performed in the order of the axis symbol of the parameter, and finally the origin return operation of all the robot axes relating to the omitted axis symbol is performed.