Sliding mode control of an exoskeleton robot based on time delay estimation

Abstract

We present an adaptive control based on robust nonlinear sliding mode and time delay estimation. This controller allows a seven degrees-of-freedom arm exoskeleton robot dealing with unknown nonlinear uncertain dynamics and external disturbances. The controller is developed in order to provide passive rehabilitation. The closed loop stability of the overall system is proved based on Lyapunov theory. The proposed controller is evaluated with healthy subjects. Experiments results show the efficiency and feasibility of the controller.