Fully-actuated System Approach-based Spacecraft Attitude Control under Tube-based Framework

This article investigates attitude control for rigid spacecraft in the presence of external disturbance and input saturation, where a novel control scheme is proposed by adopting the fully-actuated system approach, tube-based control framework and the Nussbaum function. To start with, the fully-actuated system for the spacecraft attitude dynamics is established. After that, based on the transformed system and incorporating backstepping method, an attitude controller is designed by constructing a tube-based control framework, which consists of a nominal controller and an error controller, leading the actual system to track the desired trajectory and suppressing disturbance. And the Nussbaum gain technique is also employed in order to address the time-varying input gains caused by input saturation. Through Lyapunov stability techniques, the convergence of steady-state errors and the stability of the closed-loop system are so demonstrated. An analytical simulation is then run to verify the effectiveness of the presented control strategy.