Spacecraft propellant sloshing suppression using input shaping technique

Propellant sloshing, which induces perturbations to dynamic behavior of spacecraft, is a conspicuous problem. Thus, sloshing suppression during maneuver poses a challenge on spacecraft control design. Herein, the input shaping technique, which has been validated in reducing residual vibration of flexible structure, is applied on this subject. The input shaper is designed to subject to constraints such as limited amplitude of sloshing disturbance, time optimization and capability of engine. The design procedure is described in this paper. The dynamical influence of propellant sloshing is modeled by a discrete mechanical model. The parameters of the model are calculated by use of Computational Fluid Dynamics (CFD) software and converted to a "sloshing" block to be imported in simulation loop conveniently. In an example, several types of input shapers are designed to suppress the sloshing in spherical vessel. The effectiveness of the shapers is discussed due to the computer simulation results.