Identification of Rotary Axis Angular Positioning Deviations of a Six-axis Robot by R-Test   Tianhao Cui, Soichi Ibaraki       Abstract   Numerous researchers have presented a model-based compensation scheme for the positioning error of a sixaxis robot based on the kinematic model containing position and orientation deviations of rotary axis average lines, known as the Denavit-Hartenberg (D-H) parameters. This research extends it to a new model, containing the angular positioning deviations of all the rotary axes as error sources, and its identification using the R-Test, a three-dimensional (3D) displacement probing system. The R-Test is located at multiple positions over the robot’s workspace, and a novel algorithm is presented considering that its exact positions and orientations are unknown. The prediction accuracy of the identified model is experimentally evaluated, and the significant impact of angular positioning deviations on the positioning errors is shown.   Keywords: Mechatronics and control technologies, Industrial robot, R-Test, Identification         >> Back to Home