The spacecraft attitude tracking problem is addressed with actuator faults and uncertainties among inertias, external disturbances, and, in particular, state estimates. A continuous sliding mode attitude controller is designed using attitude and angular velocity estimates from an arbitrary stable stand-alone observer. Rigorous analysis shows that the controller ensures robust stability of the entire closed-loop system as long as the observer yields state estimates with uniformly ultimately bounded estimation errors. In addition, a sequential Lyapunov analysis is utilized to obtain a convergent sequence of analytical, successively tighter upper bounds on the steady-state tracking error. Therefore, our results can be used to predict steady-state performance bounds given selected gains or facilitate gain selection given steady-state performance bounds. Numerical examples demonstrate the utility of the proposed theory.

中文翻译：

---

使用序列李雅普诺夫分析的基于观测器的容错航天器姿态跟踪

航天器姿态跟踪问题通过致动器故障和惯性、外部干扰，特别是状态估计之间的不确定性来解决。使用来自任意稳定独立观察者的姿态和角速度估计来设计连续滑模姿态控制器。严格的分析表明，只要观察者产生具有一致最终有界估计误差的状态估计，控制器就能确保整个闭环系统的鲁棒稳定性。此外，使用顺序李雅普诺夫分析来获得分析的收敛序列，稳态跟踪误差的连续上界越来越紧。所以，我们的结果可用于在给定选定增益的情况下预测稳态性能界限，或在给定稳态性能界限的情况下促进增益选择。数值例子证明了所提出的理论的实用性。