This is a study of adaptive constraint attitude control for a flexible spacecraft in the presence of inertia uncertainties, unknown disturbance, actuator saturation and faults. The proposed controller is designed by incorporating a Prescribed Performance Control (PPC) and fixed-time sliding mode control. First, a novel Nonsingular Fast Fixed-time Sliding Surface (NFFTSS) is introduced. Not only is the settling time independent of initial conditions, but also it is shorter than existing fixed-time attitude controls. Second, different from the conventional complex PPCs in the literature, a simple structure attitude controller is proposed to satisfy the transient and steady-state performance is proposed through a novel log-type PPC. An inherently continuous adaptive switching control is then presented in order to avoid the a priori not to require accurate information of the fault occurrence. Numerical simulations demonstrate that the proposed controller successfully accomplishes attitude control with high attitude pointing accuracy and stability.

这是对存在惯性不确定性，未知扰动，执行器饱和和故障的挠性航天器的自适应约束姿态控制的研究。所提出的控制器是通过结合规定的性能控制（PPC）和固定时间的滑模控制而设计的。首先，介绍了一种新颖的非奇异快速固定时间滑动曲面（NFFTSS）。稳定时间不仅与初始条件无关，而且比现有的固定时间姿态控制要短。其次，与文献中传统的复杂PPC不同，提出了一种简单的结构姿态控制器，通过新型对数型PPC来满足瞬态和稳态性能。然后提出了固有的连续自适应切换控制，以避免先验地不需要故障发生的准确信息。数值仿真表明，所提出的控制器能够成功完成姿态控制，并具有较高的姿态指向精度和稳定性。