Robot, robot control device, and robot system

• US 10,099,380 B2
• Filed: 05/18/2016
• Issued: 10/16/2018
• Est. Priority Date: 06/02/2015
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Ishige, Taro, Harada, Atsushi, Yamaguchi, Yukihiro
• Primary Examiner(s): Tran, Khoi H
• Assistant Examiner(s): Peche, Jorge O
• Application Number:
  US15/157,658
• Publication Number:
  US 20160354929A1
• Time in Patent Office: 881 Days
• CPC Class Codes: B25J 9/1692 Calibration of manipulator
• CPC Class Codes: B25J 9/1697 Vision controlled systems
• CPC Class Codes: G05B 2219/39022 Transform between measuring and manipulator coordinate system

Abstract

A robot includes: a local coordinate system deriving portion which derives a local coordinate system having two shafts which are parallel to a work plane and orthogonal to each other, based on an image in which markers illustrating three or more points on the work plane which is not horizontal are captured; and a control parameter obtaining portion which obtains control parameters via the local coordinate system.

Claims

1. A robot comprising:

plurality of arms connected via a joint;

a motor that is configured to move the joint so that one of the plurality of arms moves relative to another of the plurality of arms;

a plurality of markers that are located on the work plane;

a work plane defining an extending plane, the extending plane from the work plane being along a non-horizontal plane;

a camera that is configured to capture a first image including the markers when a positional relationship between the markers and the camera is in a first state, the camera being disposed on one of the plurality of arms;

a memory that is configured to store computer-readable instructions; and

a processor that is configured to execute the computer-readable instructions so as to;

obtain a local coordinate system based on positions of at least three of the markers in the first image, the local coordinate system having a first axis and a second axis perpendicular to each other, the first and second axes being parallel to the work plane;

obtain a control parameter via the local coordinate system;

move one of the plurality of arms so that the positional relationship between the markers and the camera is in a second state that is different from the first state;

cause the camera to capture a second image including the markers when the positional relationship between the markers and the camera is in the second state; and

perform calibration of the local coordinate system by comparing the first and second images with respect position differences of the markers,

wherein the work plane and an optical axis of the camera are perpendicular to each other when the camera captures the first and second images.

2. The robot according to claim 1,

wherein the control parameter is a coordinate of a target point to which a control object point moves, and the control object is provided at one of the plurality of arms.

3. The robot according to claim 2, further comprising:

the processor is configured to move the control object point parallel to the work plane.

4. The robot according to claim 2,

wherein the processor is configured to convert a coordinate of a third image in which the work plane is captured by the camera into a coordinate of the local coordinate system as the target point based on an input by an operator.

5. The robot according to claim 4,

wherein the processor is configured to obtain the control parameter based on the coordinate of the third image and the local coordinate system.

6. The robot according to claim 1,

wherein the control parameter is a posture of a tool mounted on one of the plurality of arms.

7. A robot control device which controls a robot, the robot control device comprising:

a memory that is configured to store computer-readable instructions; and

a processor that is configured to execute the computer-readable instruction so as to;

cause a camera to capture a first image, the first image including a plurality of markers on a work plane defining an extending plane that extends from the work plane along a non-horizontal plane, wherein the first image is captured when a positional relationship between the markers and the camera is in a first state, the camera being disposed on one of a plurality of arms of the robot;

obtain a local coordinate system based on positions of at least three of the plurality of makers in the first image, the local coordinate system having a first axis and a second axis perpendicular to each other, the first and second axes being parallel to the work plane;

obtain a control parameter via the local coordinate system;

move one of the plurality of arms so that positional relationship between the markers and the camera is in a second state that is different from the first state;

cause the camera to capture a second image including the markers when the positional relationship between the markers and the camera is in the second state; and

perform calibration of the local coordinate system by comparing the first and second images with respect position differences of the markers,

wherein the work plane and an optical axis of the camera are perpendicular to each other when the camera captures the first and second images.