Bio-inspired control research of a novel lower extremity exoskeleton with a series-parallel mechanism

Abstract

This paper proposes a switch-type and parameter self-tuning fuzzy-PID/PID controller for a novel lower extremity exoskeleton with a series-parallel mechanism according to the features of human level walking gait. The novel exoskeleton mechanism was described, the biological characteristics of human legs during the walking cycle were analyzed and a mapping from the positions of human lower extremity joints to the exoskeleton joints was established. Then the schematic of the exoskeleton control strategy was discussed and illustrated. The co-simulation method of ADAMS and MATLAB/SIMULINK was adopted and the fuzzy-PID/PID controller was designed. A 1-DOF rotation control was simulated by both the fuzzy-PID/PID controller and a conventional PID controller for comparison. Finally, the exoskeleton level walking gait was co-simulated by using the bio-inspired control strategy. The results show that the controller can provide a fast, stable and precise control for the exoskeleton system.