Using sliding mode control method to suppress fuel sloshing of a liquid-filled spacecraft

For a class of spacecrafts filled with liquid fuel, a sliding mode controller design approach is proposed to guarantee stability and at the same time attenuate fuel slosh. First, a single pendulum equivalent model is used to approximate the fuel slosh dynamics of the spacecraft. Moreover, not like most existing approaches, this method does not use the simplified model which makes two equivalent inputs for control design. In this paper, the transverse reaction jet force and the pitching moment are considered as two control inputs. Furthermore, the considered liquid-filled spacecraft has three degrees of freedom while it has only two actuators, which makes it an under-actuated system. A sliding mode control scheme is employed to design the attitude controller for such an under-actuated system. Simulation results show that the design of sliding mode controller can achieve the desired control performance.