Flatness tracking control scheme of rehabilitation exoskeleton robot with dynamic uncertainties

Artificial limbs are new robotic devices created to help stroke victims in the rehabilitation process. In this article, we focus our work on applying passive, active or assistive control strategies to provide a physical assistance and rehabilitation by a 7-degree-of-freedom exoskeleton robot with nonlinear uncertain dynamics and unknown bounded external disturbances due to the robot user's physiological characteristics. The flatness controller combined with time-delay estimation is designed for the 7-degree-of-freedom exoskeleton robot called ETS-MARSE (Ecole de Technologie Superieure-Motion Assistive Robotic-exoskeleton for Superior Extremity) in order to ensure a passive rehabilitation exercises with a high level of tracking accuracy and robustness against the uncertainty constraints. The stability analysis of such systems is proven using the Lyapunov-Krasovskii functional theory. This approach is illustrated by experimental results with healthy human to highlight the efficiency of the suggested controller scheme.