Device and Method for Calibrating the Center Point of a Tool Mounted on a Robot by Means of a Camera

• US 20080252248A1
• Filed: 01/24/2006
• Published: 10/16/2008
• Est. Priority Date: 01/26/2005
• Status: Abandoned Application

• Current Assignee: ABB AB (ABB Limited)
• Original Assignee: ABB AB (ABB Limited)
• Inventors: Lundberg, Ivan, Brogardh, Torgny, Durinder, Niklas
• Application Number:
  US11/883,127
• Publication Number:
  US 20080252248A1
• Time in Patent Office: Days
• US Class Current: 318/572
• CPC Class Codes: B25J 9/1692 Calibration of manipulator
• CPC Class Codes: B25J 9/1697 Vision controlled systems
• CPC Class Codes: G05B 2219/39394 Compensate hand position with camera detected deviation, new end effector attitude
• CPC Class Codes: G05B 2219/40607 Fixed camera to observe workspace, object, workpiece, global
• CPC Class Codes: G05B 2219/40611 Camera to monitor endpoint, end effector position

Abstract

A device and a method for tool center point calibration of an industrial robot. The device is intended to calibrate an industrial robot with respect to a tool mounted on the robot. The device includes a camera designed to take a plurality of images of at least part of the robot tool for a plurality of different tool orientations, an image-processing unit designed to determine the positions of the robot tool in the orientations based on the images, a calculation module adapted to calculate the position of the center point of the robot tool, based on the determined positions, and a control module adapted to calculate the corrective movements of the robot.

Claims

1. A device for tool center point calibration of a robot with a tool mounted on the robot, the device comprising:

a camera designed to capture a plurality of images of at least part of the robot tool for a plurality of different tool orientations,

an image-processing unit designed to determine the positions of the robot tool in said orientations based on said images,

a calculation module adapted to calculate the position of the center point of the robot tool, hereinafter referred to as the tool center point, based on said determined positions, and

a control module adapted to calculate the corrective movements of the robot.

2. The device according to claim 1, wherein the camera is arranged within the working range of the robot.

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

a light source which is arranged so that the tool is placed between the light source and the camera.

4. A method for tool center point calibration of a robot with a tool mounted on the robot, the method comprising:

capturing a first image of the tool in a first-orientation,

reorienting the tool to new orientations, whereby images of the tool are captured in the new orientations,

determining the positions of the tool in said orientations based on said images, and

calculating the tool center point based on said determined positions and updating the tool center point of the robot based on the calculated tool center point.

5. The method according to claim 4, wherein the camera is arranged within the working range of the robot.

6. The method according to claim 4, wherein the tool is illuminated by a light source from a direction opposite to the direction from which the images are captured, to obtain the best possible contrasting effect.