JPH07124889A - Control device for industrial robot - Google Patents

Abstract

PURPOSE:To provide the control device for an industrial robot, which can control the life of each part for a robot. CONSTITUTION:After a servo power supply has been applied to the robot control device, each life of a speed reducer and grease is accumulated so as to be computed by making use of motor torque which is directed to a servomotor every sampling time, and revolution. The aforesaid accumulative computed vale is compared with a reference value set in advance, if the aforesaid value is in excess of the reference value, necessity for part replacement and inspection is thereby indicated, and a warning is thereby given.

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, and more particularly to a device for controlling the reduction gear of the robot and the life of grease.

[0002]

2. Description of the Related Art Inspections of robots and replacement of parts and members are performed in advance by checking the number of months and years until the inspection and replacement of parts, and the number of months elapsed from the start of operation.

[0003]

When the number of months until the inspection and replacement of parts and the number of years are decided in advance and carried out, the lifespan of the parts may be different even if the number of months and years are the same depending on the application and the usage situation. There is waste in replacing parts that have not been replaced. Also, the number of days elapsed must be constantly checked, organized, and recorded, which is troublesome. Therefore, an object of the present invention is to provide a control device for an industrial robot that can manage the life of parts of the robot.

[0004]

According to the present invention, the torque generated by a servo motor for driving a robot manipulator, the number of revolutions at that time, and the cumulative operation time are used to calculate the life of a predetermined member at every sampling time and accumulate it. Means to do
And comparing the accumulated value with a preset reference value, and displaying the necessity of replacement or inspection of the predetermined member when the accumulated value exceeds the reference value. It is what

[0005]

After the servo controller is turned on to the robot controller, the motor torque commanded to the servo motor and the number of revolutions are used at every sampling time to cumulatively calculate the life of the reducer and the grease. This cumulative calculated value is compared with a preset reference value, and when the reference value is exceeded, the necessity of parts replacement and inspection is displayed and a warning is issued.

[0006]

Embodiments will be specifically described below with reference to embodiments of the present invention. FIG. 1 is a block diagram of an industrial robot embodying the present invention. In the figure, 20 is a robot controller, 40
Is a robot mechanism unit to which the servo motor 10 is attached. The control device 20 has a central processing unit (hereinafter referred to as CPU) 1, and the CPU 1 has a memory 2 including a ROM,
A memory 3 including a RAM, an axis control unit 6, an input / output interface 8 and the like are connected by a data bus 9. A servo amplifier 7 that drives a servo motor 10 for each axis of the robot is connected to the axis controller 6. The input / output interface 8 is provided with an I / O signal circuit for turning on / off the servo amplifier 7. Next, this embodiment will be described with reference to the flowchart of FIG. The flowchart of FIG. 2 is executed by the CPU 1, and necessary data and the like are stored in the memory 2 or 3. Turn on the servo power of the robot controller (step 100) and start normal operation (step 1).
0) While performing normal operation, start the calculation of the life of the reducer and grease used in the robot for each axis that is in parallel operation. For example, the life calculation can be done by the following formula.

[0007]

[Equation 1]

Is calculated in step 120. However, I _i is a current value and N _i is a rotation speed during normal operation. When the cumulative value is calculated, it is compared with the set value held as a parameter in advance (step 130). At this time, if the value is equal to or more than the set value, the inspection and the parts conversion requirement are displayed, and the number of times the set value has been exceeded is stored and displayed (step 140). After the display and warning, the cumulative calculation flow will be repeated. Similarly, when the value is within the set value, the cumulative calculation flow during normal operation is repeated. When either the speed reducer or the grease exceeds the set value, it may be displayed that the speed reducer and the grease and other drive system components also need to be inspected at the same time.

[0009]

As described above, when the accumulated time exceeds the set value, the display of inspection and replacement can be displayed, so that preventive maintenance and planned maintenance can be carried out in accordance with the intended use and usage situation. As a result, the inspection can be performed and the robot's ability can be fully exerted without the need for checking and recording by the maintenance person.

[Brief description of drawings]

FIG. 1 is a block diagram of an industrial robot that implements the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment of the present invention.

[Explanation of symbols]

 1 CPU 2 Memory (ROM) 3 Memory (RAM) 4 Operation Panel 5 Teach Box 6 Axis Controller 7 Servo Amplifier 8 I / O Interface 9 Data Bus 10 Servo Motor 20 Robot Controller 40 Robot Mechanism 41 Work Tool

Claims (5)

[Claims] 1. In an industrial robot control device, the torque generated by a servo motor for driving a robot manipulator, the rotational speed at that time, and the cumulative operating time are used to calculate and accumulate the life of a predetermined member for each sampling time. And a means for comparing the accumulated value with a preset reference value and displaying the necessity of replacement or inspection of the predetermined member when the accumulated value exceeds the reference value. A control device for an industrial robot characterized by the above. 2. The controller for an industrial robot according to claim 1, wherein the predetermined member is a speed reducer, and the cumulative value is a constant × (torque) ³ × revolution speed × cumulative time. 3. The control device for an industrial robot according to claim 1, wherein the predetermined member is grease and the cumulative value is a constant × (torque) ² × cumulative time. 4. The means according to claim 2 and the means according to claim 3 are provided, and when the cumulative value of one exceeds the reference value, the necessity of replacement or inspection of the other member is also displayed. The control device for an industrial robot according to claim 1, wherein: 5. A means for storing and displaying the number of times the reference value has been exceeded so far is provided.
Controller for the industrial robot described.