Attitude maneuver control of liquid-filled spacecraft with unknown inertia and disturbances

Abstract

The attitude maneuver dynamics and control strategy for a fuel-filled spacecraft with uncertain inertia and external disturbances are studied. The mathematical model of a three-axis stabilized spacecraft is established based on the law of conservation of momentum, and the liquid fuel inside the partially-filled fuel tank is represented by an equivalent two-mode spring-mass model. The adaptive sliding mode control law is designed for this kind of underactuated system, and the Lyapunov stability analysis guarantees that all system trajectories reach and remain on the sliding surface. Then, the multiple mode input shapers are used to suppress the sloshing of the fluid fuel. The numerical results show good performance and effectiveness of the control strategy.