Robust fault-tolerant attitude control of three-axis stabilized satellite

The three-axis stabilized satellite´s attitude control under repairable fault conditions is researched in this paper. With the consideration of rotational inertia uncertainty, a control effectiveness factor is used to describe the fault magnitude of satellite actuators. Moreover, the uncertainty of fault diagnosis results is also considered in the design of controller. And a feedforward control unit is introduced to decrease the influence of fault diagnosis uncertainty, Therefore the attitude controller´s absolute dependence on fault diagnosis results is avoided ultimately. The H_∞ and H₂ norms are used to signify the performance indexes of attitude information and output torques. The robust fault-tolerant attitude control is achieved by combining the state feedback with a pole assignment method. Finally, the simulation results reveal that this controller can stabilize a three-axis stabilized satellite quickly with a high precision of stabilization and pointing.