Abstract: For the control of three axis stabilized liquid filled spacecraft, the problems of robust fault tolerant attitude maneuver control with external unknown disturbances, parameters uncertainty, measurements uncertainty and actuator partial failure fault are studied. Firstly, the sloshing liquid fuel in a partially filled tank is equivalent to a viscous spherical pendulum model, and the rigid liquid coupling dynamic equations of the spacecraft are deduced by using the law of conservation of moment of momentum. Then, an adaptive robust fault tolerant controller is designed by combining the variable structure control strategy with the norm wise adaptive estimation algorithm. The designed norm adaptive control algorithm is used to effectively estimate the unknown upper bound of the lumped disturbances caused by the measurement uncertainty, and the adaptive estimation algorithm to estimate the liquid sloshing displacement variables in the tank. The proposed control strategy does not rely on precise fault information and can achieve the desired attitude maneuver task when the fault information value is uncertain. Based on Lyapunov stability analysis method, the uniform final boundedness of state variables of closed loop fault tolerant system is proved. The numerical method is used to verify the effectiveness and robustness of the proposed control method.

Key words: Liquid filled spacecraft, Attitude maneuver, Measurement uncertainty, Adaptive control, Fault tolerant control