Observer-Based Fuzzy Adaptive Fault-Tolerant Control for NSC System of USV With Sideslip Angle and Steering Machine Fault

This paper is concerned with the observer-based fuzzy adaptive fault-tolerant control problem for nonlinear steering control (NSC) system of unmanned surface vehicle (USV) with unmeasurable states, sideslip angle, and steering machine fault. To facilitate the controller design, the Takagi-Sugeno (T-S) model is used to deal with the fuzzy control problem of NSC system, and the modeling error analysis (MEA) is conducted for the T-S model using the real course tracking data. By introducing a pre-filter, the large heading change rate can be avoided and the robustness of controller is improved. Then, a fuzzy adaptive observer (FAO) is developed, based on which an adaptive mechanism is given to estimate the unmeasurable states, sideslip angle, and fault signals simultaneously. Furthermore, utilizing the online estimation information provided by FAO, a FAO-based adaptive fault-tolerant controller is designed to mitigate the effects of sideslip angle and fault. Finally, simulation examples and comparison experiment for "Qingshan" USV demonstrate the apparent performance of the developed method.