Abstract This paper proposes a fixed time disturbance observer (FTDO) based fixed time sliding mode control scheme for spacecraft proximity operations in the presence of parameter uncertainties and disturbances. The FTDO is designed to estimate the lumped disturbance which includes kinematic couplings, parameter uncertainties, and disturbances. Based on the observation of lumped disturbance, the fixed time sliding mode control is developed to achieve fixed time convergence, where the FTDO is employed to counteract the lumped disturbances and eliminate the chattering phenomenon. What’s more, the proposed control method can speed up the convergence and improve the control accuracy. Finally, the stability of the closed-loop system is proved via the Lyapunov analysis. Numerical simulations demonstrate the effectiveness of the proposed control method.

中文翻译：

---

基于扰动观测器的固定时间滑模控制用于具有耦合动力学的航天器接近操作

摘要 本文提出了一种基于固定时间干扰观测器（FTDO）的固定时间滑模控制方案，用于存在参数不确定性和干扰的航天器接近操作。FTDO 旨在估计集总干扰，包括运动耦合、参数不确定性和干扰。基于对集总扰动的观察，开发了固定时间滑模控制以实现固定时间收敛，其中采用FTDO来抵消集总扰动并消除颤振现象。更重要的是，所提出的控制方法可以加快收敛速度​​，提高控制精度。最后，通过李雅普诺夫分析证明了闭环系统的稳定性。数值模拟证明了所提出的控制方法的有效性。