Robust control concept for a hypersonic test vehicle

For an unmanned hypersonic test vehicle with ramjet propulsion, pitch control requirements and dynamics characteristics are considered. Several requirements for pitch control power are identified and applied to the test vehicle. For improving inherent damping and stability deficiencies of longitudinal characteristics, a robust control system with fixed gains is considered which features feedback of pitch rate and angle of attack. For achieving controller robustness, the Multi-Model-Approach is applied. The stabilization capability is considered in regard to existing control power margins and detrimental effects of controller time delays and rate limitations of control surface deflections.