Robust Fuzzy Terminal Sliding Mode Control for Passive Control of Upper-Limb Exoskeleton

Uncertain robotic manipulator systems, known for their high nonlinearities, unmodeled dynamics, and uncertainties, are the subject of this paper. Based on the terminal sliding mode control algorithm and its nonsingular design method, a new robust fuzzy control scheme is introduced to ensure fast and finite time convergence to the desired state. The stability of the proposed control strategy is confirmed by the Lyapunov theory, and its effectiveness is tested on a two-degrees-of-freedom robotic manipulator. Robustness and rapid convergence, as well as reducing the controller's high-frequency commutation effect, are proved.