Robust adaptive fault estimation for microsatellite attitude control systems

This paper using a fault estimation observer design method based on described system, which is subjected to actuator faults and sensor faults in nonlinear systems with unstructured uncertainties. The method has the desired robust performance index, and in the presence of uncertainties, it can achieve accurate reconstructions of abrupt faults and time-varying faults, etc. Sufficient conditions for the existence of the proposed observer have been derived based on Lyapunov stability theory, and then converted into quasi-convex Linear Matrix Inequalities(LMIs) by using the cone complementarily linearization (CCL) algorithm, consecutively using iterative algorithm to get the feasibility solutions. Finally, the performance of the fault estimation scheme derived here is evaluated extensively through applying this method into microsatellite attitude dynamics, which can effectively estimates the actuator faults and sensor faults.