ROBOT SYSTEM AND ROBOT CONTROL METHOD

• US 20140371910A1
• Filed: 06/04/2014
• Published: 12/18/2014
• Est. Priority Date: 06/17/2013
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Hayashi, Tadashi
• Granted Patent: US 9,393,696 B2
• Time in Patent Office: Days
• US Class Current: 700/259
• CPC Class Codes: B05C 11/1018 responsive to distance of target
• CPC Class Codes: B05C 5/0216 by relative movement of article and outlet according to a predetermined path
• CPC Class Codes: B25J 19/023 including video camera means
• CPC Class Codes: B25J 9/1697 Vision controlled systems
• CPC Class Codes: Y10S 901/47 Optical

Abstract

A robot system includes a robot body, a camera mounted on the robot body and capable of photographing a work piece; and a control device for driving and controlling the robot body based on a trajectory to an instruction point, which is set in advance, and, when the camera arrives at an area in which the camera is capable of photographing the work piece during this driving and controlling, driving and controlling the robot body so that the camera moves linearly toward the work piece, taking an image of the work piece with the camera while the camera is moving linearly, and measuring a position of the work piece from the taken image.

Claims

1. A robot system, comprising:

a robot body;

a camera mounted on the robot body and capable of photographing a work piece; and

a control device for driving and controlling the robot body based on a trajectory to an instruction point, which is set in advance, and, when the camera arrives at an area in which the camera is capable of photographing the work piece during this driving and controlling, driving and controlling the robot body so that the camera moves linearly toward the work piece, taking an image of the work piece with the camera while the camera is moving linearly, and measuring a position of the work piece from the taken image.

2. A robot system according to claim 1, wherein the control device drives and controls the robot body so that the camera moves linearly in parallel to an optical axis of the camera.

3. A robot system according to claim 1, wherein, when the camera arrives at the area in which the camera is capable of photographing the work piece, the control device drives and controls the robot body so that the instruction point is located on an optical axis of the camera.

4. A robot system according to claim 1,

wherein the robot body comprises a robot arm and an end effector, the end effector being mounted on a tip of the robot arm to perform a given work, and

wherein the camera is mounted on one of the robot arm and the end effector at a given angle with respect to the end effector so that a tip of the end effector is included in the taken image.

5. A robot system according to claim 3,

wherein the robot body comprises a robot arm and an end effector, the end effector being mounted on a tip of the robot arm to perform a given work, and

wherein the camera is mounted on one of the robot arm and the end effector at a given angle with respect to the end effector so that a tip of the end effector is included in the taken image.

8. A robot system according to claim 1, wherein the control device modifies the trajectory of the robot body based on the measured position of the work piece.

6. A robot system, comprising:

a robot body;

a stereo camera mounted on the robot body and capable of photographing a work piece; and

a control device for driving and controlling the robot body based on a trajectory to an instruction point, which is set in advance, and, when the stereo camera arrives at an area in which the stereo camera is capable of photographing the work piece during this driving and controlling, driving and controlling the robot body so that the stereo camera moves linearly toward the work piece, taking an image of the work piece with the stereo camera while the stereo camera is moving linearly, and measuring a three-dimensional position of the work piece from the taken image.

7. A robot system according to claim 6, wherein the control device drives and controls the robot body so that the stereo camera moves linearly in parallel to an epipolar plane including a plane that comprises two focal points of the stereo camera and the instruction point set in advance.

9. A robot system according to claim 6, wherein the control device modifies the trajectory of the robot body based on the measured three-dimensional position of the work piece.

10. A robot control method, comprising:

a linear movement control step of driving and controlling, by a control unit, a robot body based on a trajectory to an instruction point, which is set in advance, and, when a camera mounted on the robot body arrives at an area in which the camera is capable of photographing a work piece during this driving and controlling, driving and controlling the robot body so that the camera moves linearly toward the work piece;

a work piece position measuring step of taking, by the control unit, an image of the work piece with the camera while the camera is moving linearly, and measuring a position of the work piece from the taken image.

11. A robot control method according to claim 10, wherein the linear movement control step further comprises driving and controlling the robot body so that the camera moves linearly in parallel to an optical axis of the camera.

14. A robot control method according to claim 10, further comprising a trajectory modifying step of modifying, by the control unit, the trajectory of the robot body based on the measured position of the work piece.

16. A robot control program for controlling a computer so that the computer executes the steps of the robot control method according to claim 10.

18. A computer-readable recording medium having recorded thereon the robot control program according to claim 16.

12. A robot control method, comprising:

a linear movement control step of driving and controlling, by a control unit, a robot body based on a trajectory to an instruction point, which is set in advance, and, when a stereo camera mounted on the robot body arrives at an area in which the stereo camera is capable of photographing a work piece during this driving and controlling, driving and controlling the robot body so that the stereo camera moves linearly toward the work piece; and

a three-dimensional position measuring step of taking, by the control unit, an image of the work piece with the stereo camera while the stereo camera is moving linearly, and measuring a three-dimensional position of the work piece from the taken image.

13. A robot control method according to claim 12, wherein the linear movement control step further comprises driving and controlling the robot body so that the stereo camera moves linearly in parallel to an epipolar plane including a plane that comprises two focal points of the stereo camera and the instruction point.

15. A robot control method according to claim 13, further comprising a trajectory modifying step of modifying, by the control unit, the trajectory of the robot body based on the measured three-dimensional position of the work piece.

17. A robot control program for controlling a computer so that the computer executes the steps of the robot control method according to claim 13.

19. A computer-readable recording medium having recorded thereon the robot control program according to claim 17.