Satellite Controller Design using SDRE and H-Infinity Methods

Space exploration is one of the main drivers of innovation and innovative technologies. Space missions are complex and high-cost procedure, involving several steps, where the Attitude Control System (ACS) needs to be robust, reliable and perform well. The ACS is responsible for the important phase that is injection of the satellite's orbit where the angular velocities is extremely high until its attitude control associated with its normal mode of operation whose degree of pointing is extremely demanding compatible with the mission's pointing requirements. The ACS of a satellite aims at determining and controlling the attitude of the satellite, and often cannot be repaired in space. On the others hand, when satellite dynamics involves plant uncertainties and large-angle maneuvers, linear control techniques are unable to design the ACS that meet the mission requirements. In this paper one investigates the performance and robustness of the union of the SDRE (State-dependent Riccati Equation) and the H-Infinite (H∞) control techniques. This investigation development a non-linear control algorithm with greater flexibility, which allows the space engineer to design an ACS with the balance between the performance of the SDRE technique with the robustness of the H∞ technique.