Fault tolerant control approach design for satellite attitude systems with actuator multiple faults

In this paper, an active fault tolerant controller design approach is proposed for the satellite attitude systems with unknown exogenous disturbances and actuator multiple faults. First, the nonlinear satellite attitude dynamics equations with actuator faults are given. Next, a fault estimation observer is given so as to acquire the estimation value of unknown actuator faults. Then, a fault tolerant attitude controller is designed in the framework of both backstepping control and terminal sliding mode control, which guarantees that the faulty satellite closed-loop attitude control systems is asymptotical stable in finite time. Finally, the effectiveness of the proposed design method is demonstrated in a satellite attitude control systems subject to actuator multiple faults.