Simulation study of PD robot Cartesian control

The author discusses the superiority of Euler parameters over other methods for representing the orientation error in PD robot Cartesian control. A simulation study has been undertaken to investigate the convergent behavior of PD robot Cartesian control with Euler parameters. The control scheme requires large actuator forces for large orientation deviation. When the rotational angle of the orientation error approaches ±π, the required input actuator forces approach infinity, with the controller breaking down. A simple method for setting limitations on the orientation error and the velocity of the end-effector is introduced to overcome the singularity at ±π and the actuator force bounds. The simulation results support the proposed method