Quaternion-Based Robust Satellite Attitude Tracking Control

In this paper, a nonlinear robust quaternion-based controller is developed to address the three-axis attitude tracking control problem of rigid spacecraft in presence of parametric uncertainties, unknown external disturbances and sensor noise. As a first step, a robust controller is designed that compensates parametric uncertainty and disturbance effects. The robust controller then reformulated to deal also with sensor noise. Singularity free unit quaternions are used to represent the attitude of the satellite in three-dimensional space. The Lyapunov-based stability analysis is applied to prove that a uniformly ultimately bounded tracking result is achieved. Simulation results are presented to illustrate the feasibility of the proposed control strategy.