Robust attitude control for spacecraft

Abstract

This paper, deals with the spacecraft attitude tracking problems in the presence of model uncertainties and external disturbances. A modified VSC design scheme is proposed by the use of Variable Structure Control (VSC) design technique. These modified VSC laws are continuous, which are shown able to alleviate chattering drawback inherited from sign-type VSC controllers and enhance the uniformly ultimate boundedness performance suffered by saturation-type ones to asymptotic stability level. Numerical simulations are also given to demonstrate the benefits of the proposed VSC scheme.