Output Feedback Control for Upper Limb Exoskeleton Robots with Finite-Time Convergence

This study addresses the challenge of designing finite-time output feedback control for a category of 5 -degree-of-freedom upper-limb exoskeleton robotic systems. This investigation introduces an observer which is devised to ensure the convergence of observer errors to a small neighborhood of zero within finite time. Then, a finite-time output feedback controller is subsequently developed, utilizing the designed finite-time observer and the sliding model control method. The application of the homogeneous Lyapunov function, in conjunction with the Lyapunov method, demonstrates that the tracking error can be confined to a tight region around zero within a finite time frame, provided that only output measurement is utilized. Ultimately, an illustrative case is presented to demonstrate the efficacy of the introduced control strategy.