TARGET OBJECT GRIPPING APPARATUS, METHOD FOR CONTROLLING THE SAME AND STORAGE MEDIUM

• US 20130006423A1
• Filed: 06/14/2012
• Published: 01/03/2013
• Est. Priority Date: 06/28/2011
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Ito, Yoshinori, Yamamoto, Takahisa
• Granted Patent: US 9,044,858 B2
• Time in Patent Office: Days
• US Class Current: 700/259
• CPC Class Codes: B25J 9/1612 characterised by the hand, wrist, grip control
• CPC Class Codes: G05B 2219/39476 Orient hand relative to object
• CPC Class Codes: G05B 2219/39527 Workpiece detector, sensor mounted in, near hand, gripper
• CPC Class Codes: G05B 2219/39543 Recognize object and plan hand shapes in grasping movements
• CPC Class Codes: G05B 2219/40053 Pick 3-D object from pile of objects

Abstract

A target object gripping apparatus comprises: an estimation unit configured to estimate an orientation of a target object based on orientation estimation parameters; a gripping unit configured to grip the target object based on the orientation of the target object estimated by the estimation unit; a detection unit configured to detect a failure of gripping by the gripping unit; and a modifying unit configured to modify the orientation estimation parameters based on the orientation of the target object when the detection unit detects a gripping failure.

Claims

1. A target object gripping apparatus comprising:

an estimation unit configured to estimate an orientation of a target object based on orientation estimation parameters;

a gripping unit configured to grip the target object based on the orientation of the target object estimated by said estimation unit;

a detection unit configured to detect a failure of gripping by said gripping unit; and

a modifying unit configured to modify the orientation estimation parameters based on the orientation of the target object when said detection unit detects a gripping failure.

2. The apparatus according to claim 1, further comprising a calculation unit configured to calculate an orientation-specific gripping failure probability based on the orientation of the target object when said detection unit detects a gripping failure,

wherein said modifying unit modifies the orientation estimation parameters based on the orientation-specific gripping failure probability.

3. The apparatus according to claim 2, further comprising an area dividing unit configured to divide an area where the target object can exist into a plurality of areas,

wherein said calculation unit calculates an orientation-specific gripping failure probability for each area divided by said area dividing unit based on a position and orientation of the target object when said detection unit detects a gripping failure, and

said modifying unit modifies orientation estimation parameters for each area based on an orientation-specific gripping failure probability for each of the divided areas.

4. The apparatus according to claim 2, wherein the orientation estimation parameters include matching data corresponding to each orientation of the target object, and

said modifying unit modifies matching data corresponding to an orientation exhibiting the orientation-specific gripping failure probability not less than a threshold.

5. The apparatus according to claim 4, wherein said modifying unit deletes matching data corresponding to an orientation of the target object when said detection unit detects a gripping failure from the orientation estimation parameters.

6. The apparatus according to claim 1, wherein the orientation estimation parameters include a matching priority order indicating a matching order of matching data corresponding to each orientation of the target object, and

said modifying unit modifies the matching priority order so as to make a priority of matching of matching data corresponding to an orientation of the target object when said detection unit detects a gripping failure lower than a priority of matching of a target object using matching data for other orientations.

7. The apparatus according to claim 4, wherein said estimation unit comprises a correlation value calculation unit configured to calculate a correlation value between an orientation of the target object and the matching data for each orientation, and

said estimation unit estimates an orientation of the target object based on the correlation value.

8. The apparatus according to claim 7, wherein the orientation estimation parameters include a predetermined weighting coefficient corresponding to each orientation of the target object,

said estimation unit comprises a reliability calculation unit configured to calculate an orientation-specific reliability by multiplying the correlation value by the predetermined weighting coefficient corresponding to each orientation,

said estimation unit estimates an orientation of the target object based on the reliability, and

said modifying unit modifies the weighting coefficient corresponding to the orientation of the target object when said detection unit detects a gripping failure to a lower value.

9. The apparatus according to claim 1, wherein said modifying unit modifies not only the orientation estimation parameter corresponding to an orientation of the target object when said detection unit detects a gripping failure but also the orientation estimation parameter corresponding to a peripheral orientation within a predetermined range relative to the orientation.

10. The apparatus according to claim 1, wherein said detection unit detects a gripping failure based on an output from a sensor provided for said gripping unit.

11. The apparatus according to claim 1, further comprising an acceptance unit configured to accept a notification of a failure of gripping the target object which is recognized by a user,

wherein said detection unit detects a gripping failure based on the notification.

12. The apparatus according to claim 1, wherein said estimation unit estimates an orientation of the target object based on an image captured by an imaging unit.

13. The apparatus according to claim 1, wherein said estimation unit estimates an orientation of the target object based on distance information acquired from a distance measuring sensor.

14. A method for controlling a target object gripping apparatus, the method comprising the steps of:

estimating an orientation of a target object based on orientation estimation parameters;

gripping the target object based on the orientation of the target object estimated in the estimating step;

detecting a gripping failure in the gripping step; and

modifying the orientation estimation parameters based on the orientation of the target object when a gripping failure is detected in the detecting step.

15. A non-transitory computer-readable storage medium storing a computer program for causing a computer to execute each step in a method for controlling a target object gripping apparatus defined in claim 14.