JPH01321192A - Working aera limiter for robot - Google Patents

Abstract

PURPOSE:To make an accurate working area for a robot determinable by setting both maximum and minimum operation limit positions of each arm, adding a specified excess angle to each of minimum and maximum travel positions of these arms, and determining the working area of each arm on the basis of these operation limit positions. CONSTITUTION:During performance of operating programs, a position of each arm is detected by each of position detectors E1, E2, and each of minimum and maximum travel positions is judged out of the programs and stored by a storage judging means 25, while these positions are displayed by a displaying means 30. Afterward, a working area of each arm is determined by a central processing unit 20 on the basis of each of minimum and maximum operation limit positions, adding a specified excess angle to each of the minimum and maximum travel positions.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a device for limiting the work area of a robot that is adapted to perform work based on an operation program stored in a robot controller.

<Prior Art> Generally, a robot has a movement limit within which the robot itself can move, and an area in which the robot moves when it is actually used, that is, a work area.

Conventionally, this work area was determined on a system conceptual diagram showing the arrangement of the robot and its peripheral equipment, and the movement status of the robot was monitored by the robot controller to ensure worker safety during robot operation. When the robot tries to move beyond the predetermined work area, the soft limit, limit switch, etc. that sends a signal to interrupt the movement detects that the robot's arm has protruded from the work area, and the servo motor, etc. A hard limit that turns off the power to the drive unit and a mechanical limit that uses a mechanical stopper that blocks the robot arm from moving further outside the area are set to limit the work area and prevent runaways due to robot malfunction or overruns due to inertia. I try to do that.

<Problems to be Solved by the Invention> However, as described above, the work area required from the system conceptual diagram is very large and is therefore larger than the work area required on the actual machine. As a result,
There was a problem in that the installation space for the robot, including the shelves around the robot, became large.

<Means for Solving the Problems> The present invention has been made to solve the above-mentioned problems, and includes a position detector that detects the position of each arm constituting a robot, and a storage determining means for determining and storing the minimum movement position and maximum movement position of each arm from the signals; and display means for displaying the minimum movement position and maximum movement position of each arm; A maximum operating limit position and a minimum operating limit position are determined for each arm by adding a predetermined margin angle to the position, and the working area of each arm is determined based on the maximum operating limit position and minimum operating limit position. It is something.

Since the present invention has the above-described configuration, the position of each arm is detected by the position detector during execution of the operation program, and the minimum movement position and the maximum movement position are determined from the detected position by the memory determination means. It is stored and displayed on the display means. Thereafter, the work area is determined based on the minimum operating limit position and the maximum operating limit position, which are obtained by adding a predetermined margin angle to the minimum moving position and the maximum moving position.

<Example> Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is an external view of a six-axis articulated robot 10. A column 12 is installed on a base 13 of this articulated robot 10, and a body 14 is rotatably disposed on the column 12. An upper arm 15 is rotatably supported on the body 14 in a vertical plane, and a forearm 16 is rotatably supported on the tip of the upper arm 15 in a vertical plane. A beam strike 1 is attached to the tip of the forearm 16.
7 is rotatably supported around a 4th axis d, and a hand 18 is rotatably supported around a 5th axis e on the wrist 17.
Further, a flange 19 at the tip of the hand 18 is rotatably supported around six axes f.

As shown in FIG.
Encoders E1 to E6 are provided, respectively, to detect rotation angles of the rotation angles.

FIG. 2 is a block diagram showing the electrical configuration of the robot control device. 20 is CPU (central processing unit)
It is. This CPU 20 has RAM (memory) 25
．． Servo CPU22a~ for driving the servo motor
22f, operation panel 26 and C for inputting commands such as operation commands;
An RT (display device) 30 is connected to constitute a robot controller. 1 axis attached to the robot
The six-axis drive servo motors Ml-M6 are each driven by the servo CPUs 22a to 22f.

Each of the servo CPUs 22a to 22f has a CP
Output angle data θ1 to θ6 output from U20 and encoders El-E6 connected to servo motors M1 to M6
The deviation between the outputs α1 to α6 of the servo motors M1 to M is calculated, and each servo motor M1 to M
It operates to rotate 6. In addition, the outputs α1 to α6 of encoders E1 to E6 provided on the 1st to 6th axes are CP
It is configured to be input to U20.

The RAM 25 stores the operation program for operating the robot and the maximum movement position θ(i) of the 1st axis a to the 6th axis f.
A storage area is provided to store the minimum movement position θ(i)sin and the operation limit position θ(5, 1.θ(il-Lie).

Next, the operation of this device will be explained with reference to the flowcharts of FIGS. 3 and 4.

First, the memory determination means will be explained.

After setting the values of the maximum movement position θ(i)+++□ and the minimum movement position θ(i)sin to predetermined values in step 100, the operation program is executed in step 101, and step 1
02, the parameter i is set to 1. and step 103
The current angle θ of the axis indicated by parameter i, 8. After reading, the process advances to step 104. In step 104, the current angle θ3. ) and the maximum movement position θ, 1. □Compare 8 and find the current angle θ (!, is the maximum movement position θ, E). , X, the process proceeds to step 105 and the maximum movement position θ(
i) Let r*ax be the current angle θ.

After updating to step 106, the current angle θ0)
If is smaller than the maximum movement position θ(i) +++all, the process directly advances to step 106. Proceeding to step 106, the current angle θ is determined. 5. and the minimum movement position θ(i)
sin is compared, and the current angle θ (il is the minimum movement position θ
(If train is smaller, proceed to step 107 and update the minimum movement position θ(i)si+s to the current angle θ(!+), then proceed to step 108 to update the current angle θ,.

is larger than the minimum movement position θ(i)mir+, the process directly proceeds to step 108. Next, in step 108, it is determined whether the parameter i is 6 (the number of controlled axes).
It is assumed that all current angles θ(5) of the ~6 axes f have been determined, and the process proceeds to step 110. When the process proceeds to step 110, it is determined whether or not the operation of the robot 10 has been completed. If it has been completed, the process proceeds to step 111, and the process is terminated. If it has not been completed, the process proceeds to step 102. Step 111
, the maximum movement position θ1 of the l-axis a to the sixth-axis f is reached. )11
111X and the minimum movement position θ. , 1 are displayed on the CRT 30, and the process ends.

In this way, the 1st axis a to the 6th axis f during the execution of the operation program
The maximum movement position θ(t) whax and the minimum movement position θ(i
) sin is determined.

Next, the work area determining means will be explained.

In FIG. 4, after the parameter i is set to 1 in step 300, the process proceeds to step 301, and waits for the margin area ω of the axis indicated by the parameter i to be input from the operation panel 26.

When the margin area ω is input, the process proceeds to step 302, where the maximum movement position θ(i) mix and the minimum movement position θfit are input.
The margin area ω is added or subtracted from sin to obtain the working limit position θ(i
)9. ill + θ(il-1in is calculated.

And this working limit position θ3,). 11m+θ(il-
In step 303, Lie sets the i-axis soft limit 304, and the parameter i becomes 6, and the work limit position θ(i
,. Liar θ(i)-L! After steps 301 to 304 are repeated until +a is obtained, step 3
05, the working limit position θ(1) of all axes, 1. θ(i
)-Lie is displayed on the CRT 30 and the process ends.

Thereafter, the hard limit and mechanical limit may be set based on the working limit position θ(i) and Li1l+θ(i)-Las.

In the embodiment described above, the maximum working limit position θ(, ). mouth.

and the minimum working limit position θ (ml-Law) are stored in the RAM 25 as a soft limit and then displayed on the CRT 30, but the invention is not limited to this and only one of them may be performed. Working limit position θ (5). 13. and minimum working limit position θ (i) - 3, # When determining maximum movement position θ (i) wax and minimum movement position θ (
i) It may be determined manually based on +sin.

<Effects of the Invention> As described above, the present invention includes a position detector that detects the position of each arm constituting the robot, and a position detector that detects the minimum movement position of each arm from the signal of the position detector when an operation program is executed. The apparatus includes a memory determining means for determining and storing the maximum movement position, and a display means for displaying the minimum movement position and maximum movement position of each arm, and a predetermined margin angle is added to the minimum movement position and the maximum movement position. By determining the maximum operating limit position and minimum operating limit position of each arm, and determining the working area of each arm based on the maximum operating limit position and minimum operating limit position, the accurate working area of the robot can be determined. This has the advantage that the soft limit, hard limit, and mechanical limit can be set at optimal positions to save space.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side view showing the mechanical configuration of the robot, FIG. 2 is a block diagram showing the robot control device, and FIGS. 3 and 4. is a flowchart showing the processing procedure of the CPU used in the work area determining device of this embodiment. 12... Column, 13... Base, 14... Body, 15... Upper arm, 16... Forearm, 17... Wrist, 18... Hand, 19...
・Flange, 20...CPU, 22...Servo CP
U, 25...RAM126...Operation panel, 30...
C.R.T.

Claims (1)

[Claims] (1) In a robot configured to perform work based on an operation program stored in a robot controller, a position detector that detects the position of each arm that makes up the robot, and a position detector that detects the position of each arm that makes up the robot, and a position detector that detects the position of each arm when the operation program is executed. storage determining means for determining and storing the minimum movement position and maximum movement position of each arm from the signals; and display means for displaying the minimum movement position and maximum movement position of each arm; A maximum operating limit position and a minimum operating limit position are determined for each arm by adding a predetermined margin angle to the position, and the working area of each arm is determined based on the maximum operating limit position and minimum operating limit position. A robot work area limiting device characterized by: