Fixed-time control for high-precision attitude stabilization of flexible spacecraft

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. (C) 2020 European Control Association. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study introduces a novel adaptive constraint attitude control approach for a flexible spacecraft, achieving attitude control with high precision and stability in the presence of uncertainties, disturbances, actuator saturation, and faults. The proposed controller incorporates both Prescribed Performance Control (PPC) and fixed-time sliding mode control, demonstrating successful performance in numerical simulations.