Integrated adaptive guidance and control of constrained nonlinear air-breathing hypersonic vehicle models

This paper presents the design of an adaptive flight control systems for constrained air-breathing hypersonic vehicle models. The proposed architecture comprises a robust adaptive nonlinear inner-loop controller, and a self-optimizing guidance scheme that shapes the reference to be tracked in order to avoid the occurrence of control input saturations. The scheme is explicitly designed to account for the presence of a state-dependent input saturation on the control loop for the vehicle longitudinal velocity, arising from physical limitations in the propulsion system. The approach is based on the integration of a previously-developed adaptive controller with a self-tuning pre-filter which shapes the reference command to maintain the control signal within feasible values. The reference command are left unaltered whenever there is sufficient control authority for stable tracking. Simulation results are provided to show the effectiveness of the method.