Research On Attitude Control Of Spacecraft With Fuel Slosh

Some attitude control and sloshing suppression methods for a class of spacecrafts with fuel sloshare studied in this dissertation. The spacecrafts would behave like a kind of underactuated system forthey have to suppress the sloshing modes while controlling the spacecraft attitude. A pendulum modeland a multi-pendulum model are both considered for the characterization of the sloshing modes in thesystem modeling for the whole spacecraft. A reduced order model is then obtained after somereasonable assumptions. For the reduced order model based on the pendulum model, a parameteradaptive nonlinear control scheme and a sliding mode control approach are both proposed to stabilizethe spacecraft. The parameter adaptive nonlinear control method is then generalized to the systembased on the multi-pendulum model. Considering the parameter uncertainties of the fuel slosh, anindirect adaptive control method is used to design the parameter adaptive law in the parameteradaptive nonlinear control scheme and a Lyapunov-based control method is proposed to design thecontrol law. A parameter projection method is used to ensure the estimates of the parameter in areasonable range. The whole spacecraft system is divided into two subsystems while one of them isbehaved like an underactuated system in the sliding mode control approach. A sliding mode controldesign is proposed to the underactuated subsystem while the other subsystem is designed using afeedback control method. The designed controller can stabilize some states of the system, while otherstates can achieve the equilibrium due to the system’s own characteristic. Finally, simulation resultsare presented to demonstrate the effectiveness and feasibility of the two proposed controllers.