OBJECT PICKING DEVICE

• US 20100004778A1
• Filed: 06/01/2009
• Published: 01/07/2010
• Est. Priority Date: 07/04/2008
• Status: Active Grant

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Kanno, Ichiro, Arimatsu, Taro, Ban, Kazunori, Watanabe, Keisuke
• Granted Patent: US 8,295,975 B2
• Time in Patent Office: Days
• US Class Current: 700/214
• CPC Class Codes: B25J 9/1697 Vision controlled systems
• CPC Class Codes: G05B 2219/40053 Pick 3-D object from pile of objects
• CPC Class Codes: G06T 1/0014 Image feed-back for automatic industrial control, e.g. robot with camera robots B25J19/023

Abstract

An object picking device, which is inexpensive and capable of speedily and accurately picking one object at a time from a random pile state. A target detecting part of an image processing part processes an image captured by a camera and detects objects. A target selecting part selects an object among the detected objects based on a certain rule. A view line direction calculating part calculates the direction of a view line extending to the selected object. A target position estimating part estimates the position including the height of the selected object based on size information of the object in the image. Then, a grip correction calculating part calculates an amount of correction of the movement of a robot so as to grip the object by using the robot.

Claims

1. An object picking device, comprising:

a camera adapted to capture a two-dimensional image including an image of a plurality of the same kind of objects that are randomly piled;

a robot adapted to pick the objects one-by-one from the plurality of objects;

an image processing part which processes the image captured by the camera; and

a handling controlling part which controls the robot,

wherein the image processing part comprises;

a target detecting part which detects information of the two-dimensional position and the size of each objects in the image of the plurality of objects;

a data storing part which stores height information regarding the height of the existing position of an object at a reference position, the height information being associated with size information of the object in the captured image at the reference position, the data storing part also storing data regarding a feature model of the object;

a target selecting part which selects an object as a target to be picked, the object having the highest degree of priority which is calculated by using at least one of size information of an image of each detected object, a degree of coincidence between the image of the detected object and the feature model, and a degree of inclination of the image of the detected object in relation to the feature model;

a view line direction calculating part which calculates the direction of a view line of the camera in the three-dimensional field between the camera and the selected object, based on the information of the two-dimensional position of the selected object;

a target position estimating part which calculates the existing height of the selected object based on the size information of the selected object and the information of the exiting position and the size of the object at the reference position stored in the data storing part, the target position estimating part further calculating the three-dimensional position of the selected object based on the existing height of the selected object and the direction of the view line; and

a grip correction calculating part which calculates an amount of correction of the movement of the robot, the amount of correction being adapted to grip the selected object by using the robot,

wherein the handling controlling part comprising;

a movement controlling part which controls the movement of the robot, so as to move a robot hand to the three-dimensional position of the selected object, along the direction of the view line of the camera in relation to the selected object;

a contact sensing part which detects that the robot hand has come in contact with the selected object;

a grip commanding part which commands the robot hand to stop the movement thereof and grip the selected object with the robot hand when the contact sensing part detects the contact between the robot hand and the selected object; and

a pull-out commanding part which commands the robot to pull out the object gripped by the robot hand.

2. The object picking device as set forth in claim 1, wherein the degree of priority is a product sum value obtained by calculating a summation of at least two of the size information, the degree of coincidence and the degree of inclination of each of the plurality of objects after multiplying a certain coefficient to each of the size information, the degree of coincidence and the degree of inclination.

3. The object picking device as set forth in claim 1, wherein the degree of priority is a product value of at least two of the size information, the degree of coincidence and the degree of inclination of each of the plurality of objects.

4. The object picking device as set forth in claim 1, wherein the robot hand has a base part, a front end part configured to grip the selected object, and a compliance mechanism which connects the front end part to the base part so that the orientation of the front end part may be varied corresponding to the orientation of the selected object.

5. The object picking device as set forth in claim 4, wherein the front end part has an electromagnet having generally a hemispherical shape adapted to engage a hole or a recess formed in the selected object.

6. The object picking device as set forth in claim 4, wherein the front end part has a suction cup which generates vacuum adsorption force by which the suction cup adsorbingly grips the selected object.

7. The object picking device as set forth in claim 4, wherein the front end part has a chuck mechanism configured to grip the selected object.