Hydraulic Damping and Swing Assistance Control of A Robotic Electrohydraulic Transfemoral Prosthesis: Preliminary Results

This paper presents a robotic electrohydraulic transfemoral prosthesis that consists of a controllable bidirectional hydraulic damping and an electrical actuator. The embedded finite-state based controller enables the prosthesis with hydraulic damping adaptation in the stance phase and motorized swing assistance control in the swing phase during level walking. The proposed prosthesis was shorter in length than a fully powered transfemoral prosthesis. Additionally, the prosthesis with swing assistance and bi-directional hydraulic damping control could restore a better gait symmetry on knee angle assessment during level walking, compared with a hydraulic microprocessor controlled transfemoral prosthesis. Preliminary experimental results from a transfemoral amputee demonstrate the potential benefit of the proposed transfemoral prosthesis.