This article proposes a fault-tolerant finite-time controller for attitude tracking control of rigid spacecraft using intermediate quaternion in the presence of external disturbances, uncertain inertia parameter, and actuator faults. First, a novel nonsingular fast terminal sliding mode control law is derived using intermediate quaternion, free of singularity, ambiguity, and unwinding phenomenon. Second, a proposed controller is developed by combining the continuous nonsingular fast terminal sliding mode method with the finite-time disturbance observer. The key feature of the proposed control strategy is that it globally stabilizes the system in finite time, even in the presence of actuator faults, inertia uncertainty, and external disturbances. Simulation results are presented under actuator constraint to show the desirable properties and the superiority of the proposed controller compared to an asymptotic controller and nonsingular fast terminal sliding mode controller.

中文翻译：

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中间四元数用于刚性航天器姿态跟踪的容错有限时间控制器

本文提出了一种容错有限时间控制器，用于在存在外部干扰，不确定的惯性参数和执行器故障的情况下使用中间四元数对刚性航天器进行姿态跟踪控制。首先，利用中间四元数推导了一种新颖的非奇异快速终端滑模控制律，该奇异性没有奇异性，歧义性和解绕现象。其次，通过将连续非奇异快速终端滑模方法与有限时间干扰观测器相结合，开发出了一种控制器。所提出的控制策略的关键特征是，即使存在执行器故障，惯性不确定性和外部干扰，它也可以在有限的时间内全局稳定系统。