Thrust Vector Control Robustness of axial-symmetric Launch Vehicles with Fuel Slosh

Clearance of Thrust Vector Control (TVC) laws for launchers demands the capability to provide analytical certificates for the system’s robust stability. During exo-atmospheric flight, a key role is played by the ability to deal with non rigid-body effects such as fuel sloshing. Depending on its frequency and magnitude, sloshing can easily deteriorate the performance of the TVC laws to the point of threatening the stability of the system. While the current Verification and Validation (V&V) approach used in industry is limited inasmuch as it entails assessment of control law robustness using a finite set of conditions, advanced analysis techniques have the potential to clear the entire analysis space. In this paper the structured singular value analysis is used to obtain robust stability certificates for the attitude motion of an axial-symmetric launch vehicle (LV) subject to fuel sloshing.