Robust control of semi-active ankle prosthesis driven by electromyographic and electro-goniometric signals

Abstract

An electromioghraphic driven ankle prosthesis was built in this study. The artificial ankle movement was enforced using an output based automatic robust control algorithm which used the information given by a set of electromyographic and electro-goniometric sensors. The prosthesis controller was complemented with a finite state machine which was used to define the switching between the different stages of gait cycle: balancing and floor contact. The controller proposed in this study forced the tracking between the actual ankle angle of the prosthesis and some reference values obtained by a biomechanical gait cycle analysis. A set of numerical simulation was used to prove the effectiveness of the controller performance over the prosthesis. Finally, the controller was tested over the actual prosthesis with similar relevant results to those obtained in numerical simulations.