Design of Optimal Adaptive Control for Satellite Attitude in Presence of Uncertainty in Moment of Inertia

In the space missions according to uncertainties in the satellite dynamics, and due to effects of the uncertainties on satellites attitude control, an adaptive control is effective and useful. Some problems in the adaptive control theory are faced by high computing volume, difficulty in choosing design parameters, and lack of general theory for adaptation mechanism. Therefore, in this paper a new adaptive control method is used for angular velocity and attitude control problem. This method is based on adaptation and optimization concepts using Markov parameters and a linear discrete-time system, so the controller is significantly applicable to stabilization and command following. The adaptive control law is robust to mass property uncertainty, and it's developed on the special orthogonal group which avoids the singularities. Also, for comparison, LQR control method is included. Finally, simulation results and analysis indicate that in the satellite maneuvers the angular velocity and attitude of the satellite trend to the desired conditions.