Prescribed Performance Attitude-Tracking Control for Rigid Satellite Under External Disturbance

This paper addresses the attitude control problem for a rigid satellite and proposes an anti-disturbance prescribed performance control (PPC) scheme, aiming to achieve accurate attitude tracking while guaranteeing tracking performance under external disturbances. First, a prescribed-time disturbance observer (PTDO) is developed to achieve the precise and rapid estimation of external disturbances within a prescribed time. Second, an appointed-time performance function (ATPF) is introduced, based on which an asymmetric performance boundary is constructed to ensure convergence within the appointed time. Subsequently, by enforcing the constructed sliding-mode error to satisfy prescribed performance constraint, the desired tracking performance of the satellite attitude system is achieved. Third, according to Lyapunov stability theory, it is proven that the disturbance estimation error and the unconstrained error in the attitude system are uniformly ultimately bounded, thereby enabling the achievement of the desired control performance. Finally, the effectiveness of the proposed control strategy is verified via numerical simulations.