A Novel Swing Assistance Control Approach for a Powered Transfemoral Prosthesis

This work proposes a novel swing phase controller for a powered low-impedance transfemoral prostheses. The proposed control method resolves the problem of competing user and prosthesis reference control inputs by formulating prosthesis assistance as a homogeneous term in the prosthesis dynamics. In doing so, the controller effectively eliminates the prosthesis as a separate exogenous input. The controller is experimentally implemented in a prosthesis prototype on a single participant with transfemoral amputation. Experimental results indicate that the swing assistance controller increases peak knee flexion angles and minimum toe clearance during swing relative to both a daily-use prosthesis and the experimental prosthesis without swing assistance.