Adaptive Integral Sliding-Mode Control for a Class of Nonlinear Spacecraft Proximity Systems Under Multi-Source Disturbances and Unmodeled Dynamics

Abstract

Spacecraft proximity system is susceptible to harsh space environment factors and neglected nonlinearities, which can be presented as multisource disturbances and uncertainties in dynamics model. In this article, a fuzzy logical system (FLS) based state constrained adaptive integral sliding-mode control strategy is proposed to deal with those problems. A nonlinear sliding manifold is utilized to optimize the time-varying tracking errors, which averts integral windup while ensuring the convergence. Moreover, an auxiliary dynamic signal is incorporated into FLS to approach dynamic uncertainties generated by unmodeled dynamics. For the purpose of compensating the adverse influences induced by stochastic noises, several adaptive laws based on the virtual signals about norms of noise intensities are designed. Then, the stability of spacecraft proximity system is proved by Lyapunov function of stochastic system. Numerical simulation results show the boundness of all signals, which demonstrate the effectiveness of the proposed controller.