An interaction-torque controller for robotic exoskeletons with flexible joints: Preliminary experimental results

This paper presents the development of an interaction-torque control architecture for a rehabilitation exoskeleton (RehabExos) with flexible joints equipped with internal torque sensors. The architecture consists of an outer control loop, which is based on the kineto-statics of the RehabExos, and on four identical-independent inner full-state joint-torque controllers (IJTFC). The considered IJTFC demonstrate good stability, responsiveness and accuracy in tracking the desired torques generated by the outer controller. Comparison with other control strategies available from the literature is shown via analytical and experimental results, which highlight the improved performances of the proposed IJTFC method in controlling the RehabExos robot.