Mechanism and Controller Design of a Transfemoral Prosthesis with Electrohydraulic Knee and Motor-Driven Ankle

This article presents a robotic transfemoral prosthesis that consists of an electrohydraulic knee and a motor-driven ankle. The electrohydraulic knee includes a controllable hydraulic damper to provide stance control and an electrical actuator to provide swing assistance. The motor-driven ankle provides damping adaptation for different terrains. The embedded finite-state-based controller enables the knee-ankle prosthesis to facilitate the amputee's ambulation on five different terrains. The proposed knee is lightweight and compact, with low electrical energy consumption. Experimental results demonstrate the potential advantages of the proposed transfemoral prosthesis compared with the hydraulic prosthesis daily used by the subject.