Preassigned finite-time attitude control for spacecraft based on time-varying barrier Lyapunov functions

The problem of preassigned finite-time control is addressed in this paper for attitude tracking of the rigid spacecraft with parameter uncertainty and external disturbance. First, the attitude tracking error system of the rigid spacecraft is constructed. Then, a kind of preassigned finite-time functions is used to impose a priori desired performance index on the state of the constructed error system. By applying the backstepping technique, a preassigned finite-time controller is proposed to stabilize the attitude tracking error system via employing a time-varying barrier Lyapunov function. In addition, an extended state observer is introduced to estimate the lumped disturbance in the rigid spacecraft system. It is proven that the practically preassigned finite-time stability of the resultant closed-loop system can be guaranteed by the proposed controller despite the presence of parameter uncertainty and external disturbance. Finally, simulation results are presented to demonstrate the effectiveness of the developed controller design method. (C) 2020 Elsevier Masson SAS. All rights reserved.