Nonlinear control of a spacecraft with multiple fuel slosh modes

This paper studies the modeling and control problem for a spacecraft with fuel slosh dynamics. A multi-pendulum model is considered for the characterization of the most prominent sloshing modes. The control inputs are defined by the gimbal deflection angle of a non-throttable thrust engine and a pitching moment about the center of mass of the spacecraft. The control objective, as is typical in a thrust vector control design, is to control the translational velocity vector and the attitude of the spacecraft, while attenuating the sloshing modes. A nonlinear mathematical model that reflects all of these assumptions is first derived. Then, a Lyapunov-based nonlinear feedback controller is designed to achieve the control objective. Finally, a simulation example is included to demonstrate the effectiveness of the controller.