A micro-satellite attitude system using sliding mode observer and sliding mode controller with perturbation estimation

In this paper, we present sliding mode observer (SMO) and sliding mode controller with perturbation estimation (SMCPE) for a micro-satellite attitude system. In view of the microsatellite attitude system where gyro is not available or gyro fails, the quaternion estimating angle rate of satellite is proposed by means of sliding mode observer. The SMO is suitable for microsatellite which is limit by weight and power. SMCPE is applied to achieve tracking with good accuracy and enhance the robustness of the system. The simulation results about a spacecraft example show the efficiency and advantages of the proposed SMCPE method.