Adaptive fuzzy tracking control for multiple-input multiple-output nonlinear systems with sensor faults and experiment in the flexible-joint robot

This paper is centered on the adaptive asymptotic tracking control of multi-input multi-output uncertain strict-feedback nonlinear systems in the presence of both multiplicative and additive sensor faults. Through adaptive accommodation techniques, the proposed control scheme can dynamically compensate for sensor faults, thereby ensuring precise and stable control. The control scheme is devised using the backstepping design that incorporates positive integrable time-varying functions, thereby ensuring the boundedness of all signals in the closed-loop system and guaranteeing that the output tracking error asymptotically converges to zero. Additionally, extensive simulations and experimental evaluations conducted on the Quanser platform with 2-link flexible-joint robots demonstrate the efficacy of the proposed control scheme in mitigating the impact of sensor faults and achieving accurate tracking performance.