Active fault-tolerant control for satellite system via learning unknown input observer

This paper presents an active fault-tolerant control( FTC) architecture for satellite attitude control system(ACS) by combining iterative learning ideology and unknown input observer(UIO). As an integral part of active FTC system(FTCS), a learning UIO(LUIO) is proposed to achieve attitude angular velocities estimation and robust reconstruction of adaptive compensation law simultaneously based on the disturbance decoupling principle of UIO and H_∞ control ideology. Finally, simulation results on closed-loop ACS of satellite example demonstrate the effectiveness of the proposed LUIO-based approach.