Robot system, control apparatus, and control method

Patent metadata

Field	Value
Publication number	US-11623340-B2
Application number	US-202016816442-A
Country	US
Kind code	B2
Filing date	Mar 12, 2020
Priority date	Mar 13, 2019
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

A robot system includes a robot having an arm pivoting about a pivot axis (first pivot axis), a motor (first motor) pivoting the arm, a shaft (spline shaft) coupled to the arm and moving in an axial direction of a linear motion axis parallel to the pivot axis, and an inertial sensor provided in the arm or shaft, and a control apparatus having a control unit controlling the motor, wherein the inertial sensor detects an angular velocity about a roll axis orthogonal to the pivot axis and the linear motion axis or an acceleration in a tangential direction of a circle around the roll axis, and the control unit controls the motor based on information representing a pivot direction of the arm about the roll axis when the arm stops or decelerates and output from the inertial sensor.

First claim

What is claimed is:

1. A robot system comprising:
a robot having an arm pivoting about a pivot axis, a motor pivoting the arm about the pivot axis, a shaft coupled to the arm and moving in an axial direction of a linear motion axis parallel to the pivot axis, and an inertial sensor provided in the arm or shaft; and
a control apparatus having a control unit controlling the motor, wherein
the inertial sensor detects an angular velocity about a roll axis orthogonal to the pivot axis and the linear motion axis or an acceleration in a tangential direction of a circle around the roll axis,
the control unit controls the motor based on information representing a pivot direction of the arm about the roll axis when the arm stops or decelerates and output from the inertial sensor,
the shaft is provided with a load, and
the information is based on a weight of the load.

2. The robot system according to claim 1 , wherein
the arm includes a first arm pivoting about a first pivot axis and a second arm coupled to the first arm and pivoting about a second pivot axis parallel to the first pivot axis, and
the motor is a first motor pivoting the first arm about the first pivot axis.

3. The robot system according to claim 1 , wherein
the information is obtained based on the output from the inertial sensor.

4. The robot system according to claim 1 , wherein
the control unit has a memory unit, and
the information is stored in the memory unit.

5. The robot system according to claim 1 , wherein
the information has first information representing the pivot direction when the shaft is located in a first position and second information representing the pivot direction when the shaft is located in a second position higher than the first position.

6. The robot system according to claim 5 , wherein
the control unit controls the motor without using the information when the shaft is located between the first position and the second position.

7. The robot system according to claim 1 , wherein
a member forming an outer surface of the arm contains a resin.

8. A control apparatus for a robot having an arm pivoting about a pivot axis by a motor, a shaft coupled to the arm and moving in an axial direction of a linear motion axis parallel to the pivot axis, and an inertial sensor detecting an angular velocity about a roll axis orthogonal to the pivot axis and the linear motion axis or an acceleration in a tangential direction of a circle around the roll axis, comprising a control unit controlling the motor, wherein
the control unit controls the motor based on information representing a pivot direction of the arm about the roll axis when the arm stops or decelerates and output from the inertial sensor,
the shaft is provided with a load, and
the information is based on a weight of the load.

9. The control apparatus according to claim 8 , wherein
the information is obtained based on the output from the inertial sensor.

10. The control apparatus according to claim 8 , wherein
the control unit has a memory unit, and
the information is stored in the memory unit.

11. The control apparatus according to claim 10 , wherein
the information has first information representing the pivot direction when the shaft is located in a first position and second information representing the pivot direction when the shaft is located in a second position higher than the first position.

12. The control apparatus according to claim 11 , wherein
the control unit controls the motor without using the information when the shaft is located between the first position and the second position.

13. A control method for a robot having an arm pivoting about a pivot axis by a motor, a shaft coupled to the arm and moving in an axial direction of a linear motion axis parallel to the pivot axis, and an inertial sensor, comprising:
detecting an angular velocity about a roll axis orthogonal to the pivot axis and the linear motion axis or an acceleration in a tangential direction of a circle around the roll axis by the inertial sensor;
controlling the motor based on the detected angular velocity or acceleration and information representing a pivot direction of the arm about the roll axis when the arm stops or decelerates,
the information is stored information,
the shaft is provided with a load, and
the information is based on a weight of the load.

14. The control method according to claim 13 , wherein
the information is obtained based on the output from the inertial sensor.

15. The control method according to claim 13 , wherein
the information has first information representing the pivot direction when the shaft is located in a first position and second information representing the pivot direction when the shaft is located in a second position higher than the first position.

16. The control method according to claim 15 , wherein
the controlling includes controlling the motor without using the information when the shaft is located between the first position and the second position.

Assignees

• Seiko Epson Corp

Inventors

• Imai Ryosuke

Classifications

• B25J9/04 Primary

  by rotating at least one arm, excluding the head movement itself, e.g. cylindrical coordinate type or polar coordinate type · CPC title

• B25J9/0012

  making use of synthetic construction materials, e.g. plastics, composites · CPC title

• B25J9/123

  Linear actuators · CPC title

• B25J9/044

  with forearm providing vertical linear movement · CPC title

• B25J13/088 Primary

  with position, velocity or acceleration sensors · CPC title