Encoder, driving apparatus, robot apparatus, control system, and its control method

Patent metadata

Field	Value
Publication number	US-12040733-B2
Application number	US-202117211098-A
Country	US
Kind code	B2
Filing date	Mar 24, 2021
Priority date	Sep 24, 2018
Publication date	Jul 16, 2024
Grant date	Jul 16, 2024

Abstract

Provided is an encoder, which is provided in a driving apparatus comprising a motor section configured to drive a first displacement section, which is connected to a fixed section via an elastic body, and a transmission section configured to convert a displacement of the first displacement section and transmit the displacement to the second displacement section, comprising: a first detector configured to detect first displacement information of the first displacement section; a second detector configured to detect second displacement information of the second displacement section; a third detector configured to detect third displacement information of the motor section relative to the fixed section; and a computing section configured to obtain information related to a driving amount of the motor section using the first displacement information and the second displacement information, and obtain information of a load on the motor section using the third displacement information.

First claim

What is claimed is:

1. An encoder comprising:
a scale section attached to one of a fixed section and a motor case of a motor section which rotates a rotating shaft, the scale section having a pattern;
a detection section attached to an other one of the fixed section and the motor case and configured to generate a detection signal based on the pattern of the scale section; and
a computing section configured to compute information of load applied from the fixed section to the motor section based on the detection signal.

2. The encoder according to claim 1 , wherein the computing section is configured to obtain a correction value of a driving amount of the motor section using the information of the load.

3. The encoder according to claim 2 , wherein
the rotating shaft is connected to a speed reducer as an input shaft, and
the speed reducer is configured to convert a displacement of the input shaft and transmit the displacement of the input shaft that has been converted to an output shaft.

4. The encoder according to claim 3 , wherein the computing section is configured to obtain a correction value of the driving amount so as to suppress a displacement of the output shaft by a change of the load.

5. The encoder according to claim 4 , further comprising:
a first detecting section configured to detect rotation information of the input shaft, wherein
the computing section is configured to compute the driving amount based on the rotation information detected by the first detecting section.

6. The encoder according to claim 4 , further comprising:
a second detecting section configured to detect rotation information of the output shaft, wherein
the computing section is configured to compute the driving amount based on the rotation information detected by the second detecting section.

7. The encoder according to claim 5 , further comprising:
a second detecting section configured to detect rotation information of the output shaft, wherein
the computing section is configured to compute the driving amount based on the rotation information detected by the first detecting section and the rotation information detected by the second detecting section.

8. The encoder according to claim 1 , wherein the load is a torque.

9. The encoder according to claim 1 , further comprising:
an elastic body configured to connect the motor case and the fixed section to each other so that the motor case is rotatable with respect to the fixed section.

10. The encoder according to claim 9 , wherein the elastic body has elasticity around an axis parallel to the rotating shaft.

11. The encoder according to claim 9 , wherein the elastic body is a flexure, a wound spring, an elastic member, or an elastic member of a polymeric material.

12. The encoder according to claim 1 , wherein the detection section is configured to measure a rotation angle of the motor section relative to the fixed section.

13. The encoder according to claim 1 , wherein the detection section is a rotary encoder or a linear encoder.

14. The encoder according to claim 1 , wherein the scale section is reflective or transmissive.

15. The encoder according to claim 1 , wherein a type of the detection section is an optical type, a magnetic type or an electrostatic capacitive type.

16. A driving apparatus comprising:
a motor section configured to rotate an input shaft and having a motor case; and
an encoder, wherein
the encoder comprises:
a scale section attached to one of a fixed section and the motor case, the scale section having a pattern;
a detection section attached to an other one of the fixed section and the motor case and configured to generate a detection signal based on the pattern of the scale section; and
a computing section configured to compute information of load applied from the fixed section to the motor section based on the detection signal.

17. The driving apparatus according to claim 16 , further comprising a speed reducer configured to convert a displacement of the input shaft and transmit the displacement of the input shaft that has been converted to an output shaft.

18. The driving apparatus according to claim 16 , further comprising an elastic body configured to connect the motor case and the fixed section to each other so that the motor case is rotatable with respect to the fixed section.

19. The driving apparatus according to claim 16 , wherein the computing section is configured to obtain a correction value of a driving amount of the motor section using the information of the load.

20. The driving apparatus according to claim 19 , wherein
the rotating shaft is connected to an input shaft of a speed reducer, and
the speed reducer is configured to convert a displacement of the input shaft and transmit the displacement of the input shaft that has been converted to an output shaft.

21. The driving apparatus according to claim 20 , wherein the computing section is configured to obtain a correction value of the driving amount so as to suppress a displacement of the output shaft by a change of the load.

22. The driving apparatus according to claim 20 , further comprising:
a first detecting section configured to detect rotation information of the input shaft, wherein
the computing section is configured to compute the driving amount based on the rotation information detected by the first detecting section.

23. The driving apparatus according to claim 20 , further comprising:
a second detecting section configured to detect rotation information of the output shaft, wherein
the computing section is configured to compute the driving amount based on the rotation information detected by the second detecting section.

24. The driving apparatus according to claim 22 , further comprising:
a second detecting section configured to detect rotation information of the output shaft, wherein
the computing section is configured to compute the driving amount based on the rotation information detected by the first detecting section and the rotation information detected by the second detecting section.

25. A robot apparatus comprising the driving apparatus according to claim 16 .

26. A control system comprising:
a scale section attached to one of a fixed section and a motor case of a motor section which rotates a rotating shaft, the scale section having a pattern;
a detection section attached to an other one of the fixed section and the motor case and configured to generate a detection signal based on the pattern of the scale section; and
a computing section configured to compute information of load applied from the fixed section to the motor section based on the detection signal.

27. The control system according to claim 26 , further comprising:
an elastic body configured to connect the motor case and the fixed section to each other so that the motor case is rotatable with respect to the fixed section.

28. The control system according to claim 26 , wherein the computing section is configured to obtain a correction value of a driving amount of the motor section using the information of the load.

Assignees

• Nikon Corp

Inventors

• Omata Kenji
• Sakata Koichi

Classifications

• B25J19/02

  Sensing devices · CPC title

• B25J13/08

  by means of sensing devices, e.g. viewing or touching devices · CPC title

• B25J9/10

  characterised by positioning means for manipulator elements · CPC title

• G01L3/12

  involving photoelectric means · CPC title

• G01L3/14

  wherein the torque-transmitting element is other than a torsionally-flexible shaft · CPC title