WORK SYSTEM AND INFORMATION PROCESSING METHOD

• US 20100131235A1
• Filed: 11/18/2009
• Published: 05/27/2010
• Est. Priority Date: 11/26/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Aoba, Masato
• Granted Patent: US 9,239,234 B2
• Time in Patent Office: Days
• US Class Current: 702/153
• CPC Class Codes: B25J 9/1697 Vision controlled systems
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50
• CPC Class Codes: G01B 11/2504 Calibration devices
• CPC Class Codes: G01B 11/2518 Projection by scanning of the object
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80

Abstract

In a work system which measures 3D information of a target object by a light-section method, high measurement precision is realized. The invention includes a robot arm, a hand position detection member which is arranged at the distal end portion of the robot arm, a slit laser projector which irradiates slit light, a camera which is fixed at a position independent of the robot arm, and senses an image of the target object, and a computer which calculates a light-section plane of the slit light based on a light-section line formed on the hand position detection member which is included in image data of the target object obtained by image sensing by the camera, and calculates the position and orientation of the target object based on the calculated light-section plane and the light-section line formed on the target object.

Claims

1. A work system comprising:

an arm mechanism, a position and an orientation of which are configured to be changed so as to execute a predetermined work for an object to be processed placed on a work area;

a member arranged at a distal end portion of said arm mechanism;

an irradiation unit configured to form a light projection pattern on said member and on the object to be processed by irradiating said member and the object to be processed with pattern light, said irradiation unit being arranged on said arm mechanism to have a constant relative position with respect to said member;

an image sensing unit configured to sense an image of the object to be processed, said image sensing unit being fixed at a position independent of said arm mechanism;

a first calculation unit configured to calculate a position and an orientation of the distal end portion of said arm mechanism and an irradiation plane of the pattern light based on the light projection pattern formed on said member included in image data of the object to be processed which is obtained by image sensing by said image sensing unit; and

a second calculation unit configured to calculate a position and an orientation of the object to be processed based on the calculated irradiation plane and the light projection pattern formed on the object to be processed included in the image data of the object to be processed which is obtained by image sensing by said image sensing unit.

2. The system according to claim 1, further comprising a control unit configured to control an operation of said arm mechanism based on the position and the orientation of the distal end portion of said arm mechanism calculated by said first calculation unit, and the position and the orientation of the object to be processed calculated by said second calculation unit.

3. The system according to claim 1, wherein said irradiation unit is a slit light projector which irradiates said member and the object to be processed with slit light as the pattern light, and forms a light-section line as the light projection pattern on said member and on the object to be processed.

4. The system according to claim 3, wherein said member has a shape with which the light-section line formed on said member by the slit light irradiated by said irradiation unit becomes a light-section line defined by at least two straight lines.

5. The system according to claim 3, wherein said irradiation unit is configured to change an irradiation angle with respect to said member.

6. The system according to claim 5, wherein said member has a shape with which the light-section line formed on said member by the slit light irradiated by said irradiation unit becomes a light-section line defined by at least one straight line.

7. The system according to claim 6, wherein said first calculation unit calculates the positions and the orientations of the distal end portion of said arm mechanism and the light-section planes of the slit light based on a plurality of light-section lines formed by changing the irradiation angle with respect to said member.

8. The system according to claim 1, wherein said second calculation unit calculates the position and the orientation of the object to be processed based on a relationship between the position and the orientation of said arm mechanism and the irradiation plane of the pattern light, which are calculated based on a light projection pattern formed on an object having given dimensions by irradiating the object having the given dimensions with the pattern light by said irradiation unit when said arm mechanism is located at a predetermined position and orientation.

9. The system according to claim 1, wherein said irradiation unit is a pattern light projector which irradiates said member and the object to be processed with pattern light which time-serially changes, and time-serially forms light projection patterns on said member and on the object to be processed.

10. An information processing method in a work system which comprises:

an arm mechanism, a position and an orientation of which are configured to be changed so as to execute a predetermined work for an object to be processed placed on a work area;

a member arranged at a distal end portion of the arm mechanism;

an irradiation unit configured to form a light projection pattern on the member and on the object to be processed by irradiating the member and the object to be processed with pattern light, the irradiation unit being arranged on the arm mechanism to have a constant relative position to the member; and

an image sensing unit configured to sense an image of the object to be processed, the image sensing unit being fixed at a position independent of the arm mechanism, the method comprising the steps of;

calculating a position and an orientation of the distal end portion of the arm mechanism and an irradiation plane of the pattern light based on the light projection pattern formed on the member included in image data of the object to be processed which is obtained by image sensing by the image sensing unit; and

calculating a position and an orientation of the object to be processed based on the calculated irradiation plane and the light projection pattern formed on the object to be processed included in the image data of the object to be processed which is obtained by image sensing by the image sensing unit.

11. A computer-readable storage medium storing a program for making a computer execute an information processing method according to claim 10.