Rotation driving apparatus, robot apparatus, control program, and article manufacturing method

• US 10,471,593 B2
• Filed: 09/14/2016
• Issued: 11/12/2019
• 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
• Primary Examiner(s): Sample, Jonathan L
• Application Number:
  US15/265,534
• Publication Number:
  US 20170087719A1
• Time in Patent Office: 1,154 Days
• 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 configured to drive a joint comprising a first rotation shaft and a second rotation shaft;

a transmission configured to change a rotation speed of the first rotation shaft driven by the rotation driving source to a rotation speed of the second rotation shaft;

a sensor provided to obtain a rotation angle of the second rotation shaft; and

a controller configured to operate the rotation driving source such that the joint resonates, and to diagnose a state of the transmission based on a value calculated by using the rotation angle obtained by the sensor in a case where the joint is resonating.

2. The rotation driving apparatus according to claim 1, wherein, in the case of resonating the joint, the controller is configured to rotate the joint within a speed range including a rotation speed at which the resonance of the joint occurs.

3. The rotation driving apparatus according to claim 1, wherein the controller is configured to control the rotation driving source of the joint in predetermined orientation of the joint.

4. The rotation driving apparatus according to claim 1, further comprising a second sensor provided to obtain a rotation angle of the first rotation shaft,

wherein the controller is configured to diagnose the state of the transmission based on a difference between values respectively calculated by the sensor and the second sensor.

5. The rotation driving apparatus according to claim 1, wherein the controller is configured to diagnose the state of the transmission by calculating a change rate of value from the value calculated by the rotation angle obtained by the sensor in the case where the joint is resonating and a value calculated by a rotation angle previously obtained by the sensor.

18. The rotation driving apparatus according to claim 1, wherein the controller is configured to compare a predetermined value with the value calculated by using the rotation angle obtained by the sensor in the case where the joint is resonating, and to output a warning in a case where the value calculated by using the rotation angle obtained by the sensor is larger than the predetermined value.

19. The rotation driving apparatus according to claim 2, wherein the controller changes stepwise the rotation speed of the joint within the speed range.

6. A robot apparatus comprising:

a rotation driving source configured to drive a joint comprising a first rotation shaft and second rotation shaft;

a transmission configured to change a rotation speed of the first rotation shaft driven by the rotation driving source to a rotation speed of the second rotation shaft;

a sensor provided to obtain a rotation angle of the second rotation shaft; and

a controller configured to operate the rotation driving source such that the joint resonates, and to diagnose a state of the transmission based on a value calculated by using the rotation angle obtained by the sensor in the case where the joint is resonating.

9. The robot apparatus according to claim 6, wherein the controller is configured to compare a predetermined value with the value calculated by using the rotation angle obtained by the sensor in the case where the joint is resonating, and to output a warning in a case where the value calculated by using the rotation angle obtained by the sensor is larger than the predetermined value.

10. The robot apparatus according to claim 6, wherein, in the case of resonating the joint, the controller is configured to rotate the joint within a speed range including a rotation speed at which the resonance of the joint occurs.

7. An article manufacturing method of manufacturing an article by using a robot apparatus:

the robot apparatus comprising;

a rotation driving source configured to drive a joint comprising a first rotation shaft and a second rotation shaft;

a transmission configured to change a rotation speed of the first rotation shaft driven by the rotation driving source to a rotation speed of the second rotation shaft;

a sensor provided to obtain a rotation angle of the second rotation shaft; and

a controller, the method comprising;

the controller operating the rotation driving source such that the joint resonates; and

the controller diagnosing a state of the transmission based on a value calculated by using the rotation angle obtained by the sensor in a case where the joint is resonating.

11. The article manufacturing method according to claim 7, further comprising the controller comparing a predetermined value with the value calculated by using the rotation angle obtained by the sensor in the case where the joint is resonating, and outputting a warning in a case where the value calculated by using the rotation angle obtained by the sensor is larger than the predetermined value.

12. The article manufacturing method according to claim 7, wherein, in the case of resonating the joint, the controller rotates the joint within a speed range including a rotation speed at which the resonance of the joint occurs.

8. An article manufacturing method of an article manufactured by a rotation driving apparatus, the rotation driving apparatus comprising:

a rotation driving source configured to drive a joint comprising a first rotation shaft and a second rotation shaft;

a transmission configured to change a rotation speed of the first rotation shaft driven by the rotation driving source to a rotation speed of the second rotation shaft;

a sensor provided to obtain a rotation angle of the second rotation shaft; and

a controller, the method comprising;

the controller operating the rotation driving source such that the joint resonates; and

the controller diagnosing a state of the transmission based on a value calculated by using the rotation angle obtained by the sensor in a case where the joint is resonating.

13. The article manufacturing method according to claim 8, further comprising the controller comparing a predetermined value with the value calculated by using the rotation angle obtained by the sensor in the case where the joint is resonating, and outputting a warning in a case where the value calculated by using the rotation angle obtained by the sensor is larger than the predetermined value.

14. The article manufacturing method according to claim 8, wherein, in the case of resonating the joint, the controller rotates the joint within a speed range including a rotation speed at which the resonance of the joint occurs.

15. A controlling method of a rotation driving apparatus which comprises:

a rotation driving source configured to drive a joint comprising a first rotation shaft and a second rotation shaft;

a transmission configured to change a rotation speed of the first rotation shaft driven by the rotation driving source to a rotation speed of the second rotation shaft; and

a sensor provided to obtain a rotation angle of the second rotation shaft, the controlling method comprising;

operating the rotation driving source such that the joint resonates; and

diagnosing a state of the transmission based on a value calculated by using the rotation angle obtained by the sensor in a case where the joint is resonating.

16. The controlling method according to claim 15, further comprising comparing the value calculated by using the rotation angle obtained by the sensor in the case where the joint is resonating with a predetermined value, and outputting a warning in a case where the value calculated by using the rotation angle obtained by the sensor is larger than the predetermined value.

17. The controlling method according to claim 15, wherein, in the case of resonating the joint, the joint is rotated within a speed range including a rotation speed at which the resonance of the joint occurs.

20. A non-transitory computer-readable storage medium storing a control program for performing a controlling method of a rotation driving apparatus which comprises:

a rotation driving source configured to drive a joint comprising a first rotation shaft and a second rotation shaft;

a transmission configured to change a rotation speed of the first rotation shaft driven by the rotation driving source to a rotation speed of the second rotation shaft; and

a sensor provided to obtain a rotation angle of the second rotation shaft, the program comprising code to execute;

operating the rotation driving source such that the joint resonates; and

diagnosing a state of the transmission based on a value calculated by using the rotation angle obtained by the sensor in a case where the joint is resonating.