Robust Finite Time Control for Stabilization of Rigid Spacecraft

This paper investigates finite-time attitude stabilization of a rigid spacecraft in presence of external disturbance and model uncertainties. Based on Modified Rodriguez parameters (MRPs), attitude kinematics and dynamics are converted into state-space-like form, and then robust finitetime controller is designed for attitude stabilization of a rigid spacecraft. Furthermore, smooth second order sliding mode and disturbance observer, by virtue of geometric homogeneity, are employed to construct finite time attitude stabilizer, which eliminates the chattering phenomenon and the requirement of the upper bounds of the total uncertainties. Simulation results are provided to demonstrate the effectiveness of the proposed attitude controllers. Keywords-state-space-like; attitude stabilizer; finite-time convergence; disturbance observer