A technique to calibrate industrial robots with experimental verification

Abstract

A method to calibrate industrial robots is presented. Models are developed to correct problems with robot accuracy resulting from errors in the link and joint parameters, imperfections in the main spur and encoder pinion gears, and structural deformations. Additionally, a method that places a single transformation, which is a simple cyclic function of the joint angles, at the robot's end plate to compensate for the remaining inaccuracies is explored. The models used for each of the links contain only four parameters to identify. The experimental procedures used to identify the parameters of the various models proposed are discussed. An iterative technique to solve the inverse kinematic solution is presented. The procedures developed have been applied to an industrial robot. Finally, the relative effects of each of the models used to calibrate the robot are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>