Identification of a novel kinematic model of a 6-DOF robot with bidirectional angular positioning deviation of rotary axes   Koki Fukuda, Soichi Ibaraki, Md Moktadir Alam, Sho Morita, Hiroshi Usuki, Naohiro Ohtsuki, Hirotaka Yoshioka       Abstract   To further extend the application of an industrial robot to e.g. machining operations, it is important to ensure its “absolute” positioning accuracy over its entire workspace. There have been many researches studying the improvement of the absolute positioning accuracy of robot by identifying its kinematic errors from the measurement of actual 3D position of its end effector. In such a conventional research, even when all the kinematic errors are identified, the robot’s absolute positioning error is still significantly larger than e.g. a machine tool. In this research, we propose a novel kinematic model of a 6 degrees of freedom (DOF) robot, where the angular positioning error of every rotary axis is modeled as a function of command angle and rotation direction. Its identification scheme is also presented based on the measurement of the 3D end effector positions by a laser tracker. The identified kinematic model’s performance in predicting the end effector’s 3D trajectory is validated by experiment. The comparison with the conventional kinematic model is presented.   Keywords: 6-DOF Robot, Positioning error, Kinematic Model, Laser Tracker         >> Back to Home