Analysis, Development and Evaluation of Electro-Hydrostatic Technology for Lower Limb Prostheses Applications

This paper presents electro-hydrostatic actuation as a valid substitute of electro-mechanical devices for powered knee prostheses. The work covers the design of a test rig exploiting linear electro-hydrostatic actuation. Typical control laws for prosthesis actuators are discussed, implemented and validated experimentally. Particularly, this work focuses on position and admittance control syntheses enhanced with feed-forward friction compensation. Finally, the efficiency of the test rig is characterized experimentally and compared to that of classical electro-mechanical designs. It is demonstrated that the electro-hydrostatic prototype is able to fulfill its targets from a control perspective, while also having the potential to outperform electro-mechanical actuation in efficiency.