JP2635106B2 - Robot work area limiting device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for limiting a work area of a robot that performs a work based on an operation program stored in a robot controller.

<Prior Art> Generally, a robot has a movement limit at which the robot itself can move, and an area where the robot moves when it is actually used, that is, a work area. Conventionally, this work area is determined on the drawing of the system conceptual diagram showing the arrangement of the robot and its peripheral devices, and the robot controller monitors the movement state of the robot in consideration of the safety of the operator during the operation of the robot. When the robot attempts to move larger than the predetermined work area, it detects that the arm of the robot has protruded from the work area by the soft limit, limit switch, etc., which sends a movement interruption signal,
Set a hard limit to turn off the power supply of the drive device such as a servomotor, and a mechanical limit by a mechanical stopper that blocks the robot arm from moving out of the area any more. It tries to prevent overrun.

<Problem to be Solved by the Invention> However, as described above, the work area required from the drawing of the system conceptual diagram is very rough, and is larger than the required work area on the actual machine. As a result, there is a problem that the robot installation space including the shelf around the robot becomes large.

<Means for Solving the Problems> The present invention has been made to solve the above-described problem, and has a position detector for detecting the position of each arm constituting a robot, and the position detector for executing an operation program. And a display for displaying the minimum movement position and the maximum movement position of each arm, and a display means for displaying the minimum movement position and the maximum movement position of each arm. The maximum operation limit position and the minimum operation limit position of each arm with a predetermined margin angle added to the position are determined, and the working area of each arm is determined based on the maximum operation limit position and the minimum operation limit position. Things.

<Operation> Since the present invention has the above-described configuration, the position of each arm is detected by the position detector during the execution of the operation program, and the minimum and maximum movement positions are determined from this by the storage determination means. The information is stored and displayed by the display means. Thereafter, the work area is determined based on the minimum operation limit position and the maximum operation limit position obtained by adding a predetermined margin angle to the minimum movement position and the maximum movement position.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings. First
The figure is an external view of a six-axis articulated robot 10. A column 12 is provided on a base 13 of the articulated robot 10, and the column 12 has a body 14 rotatably disposed. An upper arm 15 is rotatably supported on the body 14 in a vertical plane, and a forearm 16 is attached to a tip of the upper arm 15.
Are rotatably supported in a vertical plane. A wrist 17 is rotatably supported around four axes d at the tip of the forearm 16, and a hand 18 is rotatably supported around five axes e on the wrist 17. Part flange
19 is rotatably supported around six axes f. And
As shown in FIG. 2, servomotors M1 to M6 and encoders E1 to E6 for detecting the rotation angles of the servomotors M1 to M6 are provided on the axes a to f, respectively.

FIG. 2 is a block diagram showing an electric configuration of the control device of the robot. 20 is a CPU (central processing unit). The CPU 20 is connected to a RAM (memory) 25, servo CPUs 22a to 22f for driving servo motors, an operation panel 26 for inputting commands such as operation commands, and a CRT (display device) 30 to constitute a robot controller. ing. Servo motors M1 to M6 for driving 1 to 6 axes mounted on robot
Are driven by servo CPUs 22a to 22f, respectively.

The servo CPUs 22a to 22f respectively include output angle data θ1 to θ6 output from the CPU 20 and servo motors M1 to M6.
And calculates the deviation between the outputs α1 to α6 of the encoders E1 to E6 connected to the servomotors M1 to M6, and operates to rotate the servomotors M1 to M6 at a speed corresponding to the magnitude of the calculated deviation. The outputs α1 to α6 of the encoders E1 to E6 provided for the 1st to 6th axes are input to the CPU 20.

The RAM 25 includes an operation program for operating the robot, a maximum movement position θ _{(i) max} , a minimum movement position θ _{(i) min,} and an operation limit position θ _{(i) + Lim of} the axes a to f. θ
_(i) A storage area for storing _-Lim is provided.

Next, the operation of the present apparatus will be described with reference to the flowcharts of FIGS.

 First, the storage determination means will be described.

In step 100, the values of the maximum movement position θ _{(i) max} and the minimum movement position θ _{(i) min} are set to predetermined amounts, then the operation program is executed in step 101, and the parameter i is set in step 102.
Is set to 1. Then, in step 103, the current angle θ _(i) value of the axis indicated by the parameter i is read, and then in step 104
Proceed to. In step 104, the current angle θ _(i) is compared with the maximum movement position θ _{(i) max} , and the current angle θ _(i) is compared with the maximum movement position θ.
_{If (i)} is larger than _max , the process proceeds to step 105, where the maximum movement position θ _{(i) max} is updated to the current angle θ _(i) , and then step 1
The process proceeds to step 106, and if the current angle θ _(i) is smaller than the maximum movement position θ _{(i) max, the process} directly proceeds to step 106. Step 106
The current angle θ _(i) and the minimum movement position θ _{(i) min}
If the current angle θ _(i) is smaller than the minimum movement position θ _{(i) min} , the routine proceeds to step 107, where the minimum movement position θ
proceeds _{(i) min} to step 108 after updating the current angle theta _(i), the current angle theta _(i) is greater than the minimum movement position θ _{(i) min} directly proceeds to step 108. Next, at step 108, it is determined whether or not the parameter i is 6 (the number of control axes). If it is not 6, the routine proceeds to step 109, where 1 is added to the parameter i.
It is determined that all the current angles θ _(i) of the six axes f have been determined, and the process proceeds to step 110. When the operation proceeds to step 110, it is determined whether or not the operation of the robot 10 has been completed. If the operation has been completed, the operation proceeds to step 111, and the processing ends. When the process proceeds to step 111, one axis a to 6
The maximum movement position θ _{(i) max} and the minimum movement position θ _{(i) min} of axis f
The message is displayed on the CRT 30 and the process ends.

In this manner, the movements of the axes a to f during execution of the operation program are monitored in real time, and the maximum movement position θ _{(i) max} and the minimum movement position θ _{(i) min of} each axis are determined.

 Next, the work area determining means will be described.

In FIG. 4, after the parameter i is set to 1 in step 300, the process proceeds to step 301, and waits until the margin area ω of the axis indicated by the parameter i is 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) max} and the minimum movement position θ _{(i) min
Are added and subtracted} to obtain work limit positions θ _{(i) + Lim} and θ _{(i) -Lim} . And this work limit position θ _{(i) + Lim} , θ _{(i) -Lim}
Is stored in the RAM 25 as the soft limit of the i-axis in the step 303, and then the parameter i becomes 6 in the step 304 and the work limit positions θ _{(i) + Lim} and θ _{(i) -Lim of} all the axes are obtained in the step 301. After Steps 304 to 304 are repeated, in step 305, the work limit positions θ _{(i) + Lim} , θ of all axes
_{(i) Display -Lim} on CRT30 and end the process.

Thereafter, the hard limit and the mechanical limit may be set based on the work limit positions θ _{(i) + Lim} and θ _{(i) -Lim} .

In the above embodiment, the maximum operation limit position θ _{(i) + Lim} and the minimum operation limit position θ _{(i) -Lim} are stored in the RAM 25 as soft limits and then displayed on the CRT 30. Alternatively, only one of them may be performed.
In addition, when the maximum working limit position θ _{(i) + Lim} and the minimum working limit position θ _{(i) −Lim} are obtained, they are manually obtained based on the maximum moving position θ _{(i) max} and the minimum moving position θ _{(i) min.} May be.

<Effect of the Invention> As described above, in the present invention, the position detector for detecting the position of each arm constituting the robot, and the minimum movement position of each arm based on the signal of the position detector when executing the operation program. A storage determining unit that determines and stores the maximum movement position; and a display unit that displays the minimum movement position and the 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 operation limit position and the minimum operation limit position of each arm and determining the work area of each arm based on the maximum operation limit position and the minimum operation limit position, an accurate work area of the robot can be obtained. There is an advantage that space can be saved by setting the soft limit, the hard limit, and the mechanical limit at optimal positions.

[Brief description of the drawings]

1 shows an embodiment of the present invention. FIG. 1 is a side view showing a mechanical configuration of a robot, FIG. 2 is a block diagram showing a control device of the robot, and FIGS. 4 is a flowchart illustrating a processing procedure of a CPU used in the work area determination device of the present embodiment. 12 ... column, 13 ... base, 14 ... body, 15 ... upper arm, 16 ... forearm, 17 ... list,
18 ... hand, 19 ... flange, 20 ... CPU, 22 ... servo CPU, 25 ... RAM, 26 ... operation panel, 30 ... CRT.

Claims (1)

(57) [Claims] 1. A robot adapted to perform an operation based on an operation program stored in a robot controller, a position detector for detecting a position of each arm constituting the robot, and a position detector for executing the operation program. A storage determination unit that determines and stores the minimum movement position and the maximum movement position of each arm from the signal of the detector, and a display unit that displays the minimum movement position and the maximum movement position of each arm; and A maximum operation limit position and a minimum operation limit position of each arm obtained by adding a predetermined margin angle to the maximum movement position are determined, and a work area of each arm is determined based on the maximum operation limit position and the minimum operation limit position. A work area limiting device for a robot, comprising: