Three phase motion control of robotic arms

Numerous tasks performed by robotic arms consist of three phase motions, namely, an unconstrained motion, a transient, and a constrained motion. Only a few investigations attempt to regard such motions as a whole. The associated hurdle, namely, the change in the number of degrees of freedom, is dealt with in the present work with the aid of the recently introduced theory of imposition of constraints. Inspired by this theory, a new robust impedance control scheme, combining sliding mode and computed torque techniques, is introduced and compared to existing control schemes. The merits of simulation programs based on the new scheme, namely, run-time reduction, joint torques moderation and improved targeted contact force control, are demonstrated discussed.