Robust attitude control of low earth orbit small satellite subject to actuator saturation

The electromagnetic torquer is the most common method to generate torque for attitude control of low earth orbit (LEO) small satellite. Due to power consideration, an actuator saturation is one of serious problem in practice. In this paper, we propose the scheme to design the robust controller to stabilize a satellite attitude by considering the actuator saturation as a structured uncertainty which is based on integral quadratic constraint. The proposed robust controller is of linear time varying controller that has similar structure as conventional linear quadratic regulator (LQR). The simulation results show that our proposed robust controller outperforms an LQR controller.