Frozen-time and time-varying robust stability certificates for the coupled pitch/yaw motion of an axial-symmetric launch vehicle

Clearance of Thrust Vector Control laws for launchers demands the capability to provide analytical certificates for the system's robust stability with respect to nonzero roll rates. The current Verification and Validation approach used in industry is limited in as much as it entails evaluation of gain margins for a finite set of conditions and assuming a frozen-time setting. Advanced analysis techniques, such as mu analysis and Integral Quadratic Constraints, have the potential to clear the whole analysis space and take into consideration nonlinear and time-varying aspects. The contribution of this paper stands in exploiting such potential to provide frozen-time and time-varying robust stability certificates for the coupled pitch/yaw attitude motion of an axial-symmetric launch vehicle.