ROTATION DRIVING APPARATUS, ROBOT APPARATUS, CONTROL PROGRAM, AND ARTICLE MANUFACTURING METHOD

• US 20170087719A1
• Filed: 09/14/2016
• Published: 03/30/2017
• Est. Priority Date: 09/24/2015
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tsuchiya, Yutaka
• Granted Patent: US 10,471,593 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B25J 9/1651 acceleration, rate control
• CPC Class Codes: B25J 9/1694 characterised by use of sensors other than normal servo-feedback from position, speed or acceleration sensors, perception control, multi-sensor controlled systems, sensor fusion
• CPC Class Codes: G05B 19/4065 Monitoring tool breakage, life or condition
• CPC Class Codes: G05B 2219/37209 Estimate life of gear, drive
• CPC Class Codes: G05B 2219/37337 Noise, acoustic emission, sound

Abstract

A joint of a robot comprises a servo motor, a speed reducer driven by the servo motor, and an output-side encoder for measuring a rotation angle of the output-side rotation shaft of the speed reducer, and the position/orientation of the robot is controlled by the joint. The present invention, which aims to be able to detect certainly and at a high speed the state of the speed reducer, is characterized by driving the joint via the speed reducer by rotating the servo motor, obtaining a resonance amplitude of the joint from the rotation angle obtained from the output-side encoder, and thus diagnosing the lifetime of the speed reducer according to the obtained resonance amplitude of the joint.

Claims

1. A rotation driving apparatus which comprises a rotation driving source, a transmission configured to change a rotation speed of an input-side rotation shaft driven by the rotation driving source and drive an output-side rotation shaft, an output-side sensor provided to obtain a rotation angle of the output-side rotation shaft, and a controlling device configured to control the rotation driving source, wherein

the controlling device comprises a unit configured to obtain a resonance amplitude of a joint from a value of the output-side sensor.

2. The rotation driving apparatus according to claim 1, wherein the controlling device comprises a displaying unit configured to display a warning in a case where the resonance amplitude of the joint exceeds a predetermined reference value.

3. The rotation driving apparatus according to claim 1, wherein the unit configured to obtain the resonance amplitude of joint uses the value of the output-side sensor obtained at a time when the controlling device drives the rotation driving source such that the joint rotates within a speed range including a rotation speed at which strongest resonance of the joint occurs.

4. The rotation driving apparatus according to claim 3, wherein the controlling device sets a maximum resonance amplitude obtained by changing stepwise the rotation speed of the joint within the speed range, as the resonance amplitude of the joint.

5. The rotation driving apparatus according to claim 1, wherein the controlling device sets a maximum value of oscillation of a frequency component centering on a resonance frequency corresponding to a character frequency of the joint in a specific orientation of the joint, as the resonance amplitude of the joint.

6. The rotation driving apparatus according to claim 1, further comprising an input-side sensor provided to obtain a rotation angle of the input-side rotation shaft,

wherein the controlling device is configured to obtain the resonance amplitude of the joint based on an angle difference obtained by values output by the output-side sensor and the input-side sensor.

7. The rotation driving apparatus according to claim 1, wherein the controlling device comprises a displaying unit configured to calculate a change rate of resonance amplitude of joint from the resonance amplitude of the joint and a past resonance amplitude of the joint, and display a warning in a case where the calculated change rate exceeds a predetermined reference value.

8. A control program for causing the controlling device of the rotation driving apparatus according to claim 1 to perform an operation of the rotation driving apparatus.

9. A non-transitory computer-readable recording medium which stores therein the control program according to claim 8.

10. A robot apparatus which comprises the rotation driving apparatus according to claim 1.

11. An article manufacturing method of manufacturing an article by using the robot apparatus according to claim 10.