Most attitude control scenarios are highly affected by fuel slosh dynamics that must be carefully taken into account to preserve pointing accuracy. Since such dynamics are not easily predictable, standard strategies consist of bounding the performances of the control system to avoid interactions between the rigid dynamics of the spacecraft and the oscillating liquid motion inside the fuel tank. Thanks to a recently developed control-oriented CFD-based fuel slosh model, alternative and complementary approaches have been evaluated. The first one is based on a reformulation of the slosh effects in the Linear-Parameter-Varying (LPV) framework from which a robust LPV observer is easily derived. The estimated disturbance slosh torque is then used in a standard compensation scheme enriched by a reference governor device in order to avoid any saturation in the reaction wheel system. The second approach is based on an extension of the famous MRAC adaptive control scheme: the MCS (Minimal Control Synthesis). This approach provides excellent results and offers a very flexible framework that permits, by combining the two strategies, to reduce the adaptive gains. Such a complementarity will be further investigated in a future work.
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