Stabilization of Robots With Actuator Constraints via Interconnection and Damping Assignment

Actuator limitations hinder high-performance control of robotic manipulators. The problem is particularly challenging in case of underactuated robots where the issue has received less attention. In this brief, we investigate stabilization of manipulators under input constraints via total energy shaping. For this purpose, we use interconnection and damping assignment passivity-based control (IDA-PBC) together with an optimization technique to keep actuator torque close to allowable limits. Using a subsequent technique, the actuator torques are ensured to stay within the specified bounds for special classes of manipulators. The results are verified through simulations on a 2 degree-of-freedom (DOF) SpiderCrane. Moreover, experiments on a cable-driven robot (CDR) demonstrate performance of the proposed method.