Research on Determining the Pose Errors in a Robot Welding Cell using Theodolits

摘要

In this article, the authors aim to develop a method for determining the components errors of a robotic welding cell, using coordinate transformations between the reference systems attached to the cell's components. Errors are expressed as matrices, as it is usual in the mathematical expressions used in robotics. Errors mathematical modeling refers to the positioning error and also to the orientation error. Therefore, a test cube is used. The experiments presented in the paper, approaches only the positiong error (AP). The method is used for measuring the pose errors of a welding cell, using two theodolits. The method is based on measuring the coordinates of a target characteristic point TCP, the corner of a test cube, relative to a coordinate system attached to one of the two theodolits. It is part of the "no contact" measurement methods. The main principles of the method and its theoretical basis are validated by experiments, conducted in a welding cell, using a robot CLOOS-Romat in the Robotics Laboratory of the University "Politehnica" of Timisoara.