关键词: 航天器, 指定时间收敛, 保性能控制, 自适应控制, 姿态跟踪

Abstract: In this paper, a specified-time adaptive guaranteed-performance control scheme is proposed for the spacecraft attitude track-ing control problem under external disturbances and inertial uncertainties. First, the attitude kinematics, dynamics, and track-ing error models are established based on the modified Rodrigues parameters. By transforming the constrained tracking prob-lem into an unconstrained one via monotonic preset performance and error transformation functions, a quantitative mapping is established among user-tunable performance indices (steady-state accuracy, convergence time, and overshoot). Further-more, an exponential-polynomial combined time-varying gain function is designed to ensure a smooth transition of the system state from the transient to the steady-state phase, thereby avoiding non-smooth behaviors caused by control law switching. On this basis, an adaptive fuzzy guaranteed performance controller is developed to ensure that the attitude tracking error converges to a neighborhood of the origin within the prescribed time while strictly satisfying the preset performance constraints. Based on Lyapunov stability theory, it is proven that all signals in the closed-loop system are uniformly ultimately bounded, and the effectiveness and engineering applicability of the proposed strategy are verified through numerical simulations.

Key words: Spacecraft, specified-time convergence, prescribed performance control, adaptive control, attitude tracking