The requirements for the control performances of space manipulators, especially for the stability and accuracy of the attitude control systems of the base spacecrafts, are ever increasing during the space target capturing tasks. However, the system uncertainties caused by parameter variations will degrade the system performances severely. This paper investigates the precise and fast trajectory tracking control problem for the free-flying space manipulator, after capturing a space target with uncertain mass. To compensate the system uncertainty with complex and uncertain dynamics, a novel adaptive sliding mode disturbance observer (ASMDO) is proposed. Then, a composite controller with prescribed transient and steady-state performances is developed. It is proved that the estimation error of ASMDO can be stabilized in finite-time, though the bound of the derivative of system uncertainty is unknown. Meanwhile, the trajectory tracking error can also be stabilized in finite-time and has preassigned maximum overshoot and steady-state error. Finally, numerical simulations and experimental studies are presented to demonstrate the effectiveness of proposed methods.

中文翻译：

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基于自适应滑模扰动观测器的目标捕获空间机械臂预定性能复合控制


空间目标捕获任务对空间机械臂的控制性能，尤其是基础航天器姿态控制系统的稳定性和精度要求不断提高。然而，参数变化引起的系统不确定性会严重降低系统性能。本文研究了自由飞行空间机械臂捕获质量不确定的空间目标后精确快速的轨迹跟踪控制问题。为了补偿具有复杂和不确定动态的系统不确定性，提出了一种新型自适应滑模扰动观测器（ASMDO）。然后，开发了具有指定瞬态和稳态性能的复合控制器。证明了在系统不确定性导数的上界未知的情况下，ASMDO的估计误差能够在有限时间内稳定。同时，轨迹跟踪误差也可以在有限时间内稳定，并具有预先指定的最大超调和稳态误差。最后，数值模拟和实验研究证明了所提出方法的有效性。