Keywords
Citation
Hollingum, J. (2000), "Tool calibration", Industrial Robot, Vol. 27 No. 6. https://doi.org/10.1108/ir.2000.04927fad.012
Publisher
:Emerald Group Publishing Limited
Copyright © 2000, MCB UP Limited
Tool calibration
Keywords Calibration, Robots
Applicant: PHT Inc. (US)Patent number: US5929584Publication date: 27 July 1999Title: Tool center point calibration apparatus and method
The present invention provides a method and apparatus to precisely calibrate a so-called tool center point of a tool, or end-effector, mounted to the faceplate of a robotic machine to point locations in three dimensional space. Use of the method ensures the accuracy of programs that command placement of a tool in three dimensional point locations. The invention provides a method and apparatus for the calibration of tool centre point of robotic tools, and the calibration of the tool definition of axis symmetric robotic tools. The calibration apparatus is any metallic, electrically conducting block placed in an arbitrary but fixed location within the machine's operating envelope. The electrical contact created by the tool touching the calibration block is used to indicate the location of the tool. Electrical contact is but one method of sensing touch contact; other methods of contact sensing can be used without changing the function and usefulness of the methods described. The invention includes a method for calculating the centre point of a robotic tool, and calculating the tool definition of an axis symmetric tool. The method includes the steps of calibrating the fixed location, both position and orientation, of the calibration apparatus within the robot's envelope. The method includes the steps of measuring the location of the robotic tool by bringing it under robot control into electrical contact with the calibration apparatus and from those contact measurements calculating the tool centre point.
Jack Hollingum