Research On Attitude Control Of Spacecraft With Fuel Slosh

With the development of aerospace technology, more and morecomplicated applications are inevitably accompaniedby various kinds of higher requirements for a kind of large spacecraft, which canbe characterized by more on-orbit tasks and longeron-orbit time.In order to prolong the working life ofspacecraft and improve its stability, a large amountof liquid fuel must be carried. Hence, it will causethe fuel sloshing when the spacecraftalters the orbitor maneuvers with a partially full fuel tank. As aconsequence, a disturbance torque on the spacecraft isgenerated by the fuel slosh. This solid-liquid couplingsystem presents the nonlinear and parameter time-varying characteristics, which has to be sufficiently considered in the design of the attitude control system of the liquid-filled spacecraft.In this paper, two kinds of models are proposed to describe the spacecraft with fuel slosh. A detailed analysis is made on the models of the liquid-filled spacecraft, and it clearly points out the target need to control. A state feedback law based on Lyapunov theory is designed and a reduced-order slosh state observer is proposed to estimate the immeasurable slosh states to fit the engineering requirements. Further, the state dependence Riccati equations(SDRE) method is used to design the optimal controller without linearization. Besides, with the consideration of the external uncertainties interference, an approach of integral sliding mode variable structure controller is proposed, which greatly enhances the robustness of SDRE. Finally, a tensor product(TP) model transformation is proposed, which is based on the liner matrix inequality(LMI) and high order singular value decomposition(HOSVD). The TP model transformation is a numericalmethod, which can beeffectively solved by convex optimization methods. In addition, the proposed method isrobust against the uncertainties and disturbances sincethe controller keeps valid for all the system sets withinthe convex-bounded system obtained by the sampling. All simulation results for spacecraft verify that the design methods can make the spacecraftasymptotically stable and demonstrate the effectivenessof the proposedcontrollers.