Adaptive Fuzzy Finite-Time Constraint Control for Attitude Tracking of Rigid Spacecrafts

This article proposes an adaptive fuzzy finite-time constraint control scheme for attitude tracking of rigid spacecrafts with inertia uncertainties and external disturbances. A novel modified prescribed performance function (MPPF) is constructed for characterizing the convergence rate and steady state of the attitude tracking error, such that the tracking error can converge to a prescribed small region within a finite time. Fuzzy logic systems (FLSs) are used to approximate the unknown and nonlinear functions of the spacecraft system. Then, a finite-time adaptive backstepping controller is designed to improve the error convergence performance, and the singularity problem caused by the differentiation of the virtual control can be avoided by the presented controller. Finally, the simulations are given to show the effectiveness of the proposed scheme.