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This article focuses on the problem of adaptive fixed-time dynamic surface fault-tolerant control for a class of strict-feedback nonlinear systems subject to sensor faults. The sensor faults include bias, drift, loss of accuracy and loss of effectiveness. Our control objective is to construct an adaptive fixed-time fault-tolerant controller to ensure that the system output tracks a desired trajectory within fixed time and the tracking error converges to a small area of zero whether the sensor faults occur or what kind of sensor faults take place. One of the characteristics of our proposed scheme is that its tracking time has no connection with the initial conditions of the system. Furthermore, as for unknown nonlinear functions, fuzzy logic systems are utilized to approximate them. And the complex calculation problem, which exists in the traditional backstepping method, has been dealt with by using the dynamic surface control technique. The proposed controller takes into account the reliability, rapidity, robustness and anti-interference of the system simultaneously, and the singularity problem in controller design is solved. In the end, the simulation results illustrate that the presented strategy is feasible and effective.

This article investigates the tracking control problem of adaptive fault‐tolerant control (AFTC) for a class of strict‐feedback nonlinear systems with actuator/sensor faults and unmatched disturbances. The sensor/actuator faults include bias, drift, loss of accuracy, and loss of effectiveness. Our main control objective is to investigate an adaptive fault‐tolerant control algorithm with the help of tuning functions, adaptive control technology, fuzzy logic systems (FLSs) and so on. For unknown nonlinear functions and fault items, FLSs and adaptive control technology are utilized to approximate them. Furthermore, over‐parameterization problem existed in the backstepping‐based controller design is solved by introducing the tuning functions. Theoretical analysis proves that our proposed AFTC scheme can ensure that all the signals in the closed‐loop system are bounded and the tracking error remains within a small range of zero even if a series of faults mentioned above occur. In the end, the simulation results show that the presented AFTC strategy is feasible and effective.

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