ABSTRACT An observer-based robust adaptive Fault Tolerant Control approach is proposed in this paper to tackle the problem of trajectory tracking for a quadrotor unmanned aerial vehicle (UAV) suffering simultaneous actuator faults, exogenous disturbances and actuator saturation limits. An adaptive fuzzy state observer is proposed to estimate the immeasurable states by using fuzzy logic systems to approximate the unknown nonlinear functions of the uncertain system model. Based on the estimates of the fuzzy observer, an Integral Terminal Sliding Mode Controller that guarantees finite time convergence of the states to a small neighbourhood of zero, even under impaired conditions, is developed. Stability analysis was carried over using the Lyapunov method. The proposed approach was implemented to a quadrotor UAV and its performance was assessed under nominal conditions, and by subjecting the quadrotor to disturbances, simultaneously occurring actuator faults and input saturation limits. Excellent tracking performance and robustness even under worst-case scenarios are among the positive features of the proposed approach.

中文翻译：

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致动器同时故障和外源干扰的四旋翼无人机的容错跟踪控制

摘要 本文提出了一种基于观测器的鲁棒自适应容错控制方法，以解决同时遭受执行器故障、外源干扰和执行器饱和限制的四旋翼无人机 (UAV) 的轨迹跟踪问题。提出了一种自适应模糊状态观测器，通过使用模糊逻辑系统来逼近不确定系统模型的未知非线性函数来估计不可测状态。基于模糊观测器的估计，开发了一种积分终端滑模控制器，即使在受损条件下，它也能保证状态在有限时间内收敛到零的小邻域。使用李雅普诺夫方法进行稳定性分析。所提出的方法应用于四旋翼无人机，并在标称条件下评估其性能，并通过使四旋翼受到干扰、同时发生的执行器故障和输入饱和限制。即使在最坏的情况下，出色的跟踪性能和鲁棒性也是所提出方法的积极特征之一。