Direct Adaptive Stability & Command Augmentation of an Air-Breathing Hypersonic Vehicle

In this paper we explore a Direct Adaptive Control scheme for stabilizing a non-linear, physics based model of the longitudinal dynamics for an air breathing hypersonic vehicle. The model derived from first principles, captures the complex interactions between the propulsion system, aerodynamics, and structural dynamics. The linearized aircraft dynamics show both unstable and non-minimum phase characteristics. It also shows a strong short-period coupling with the fuselage bending mode. The value added by direct adaptive control scheme and the theoretical requirements for stable convergent operation is displayed. One of the main benefits of this control scheme is that it can be implemented knowing very little detail about the plant. The implementation uses only measured output feedback to accomplish the adaptation. A stability analysis is done on the linearized plant to understand the interaction of the adaptive controller with the propulsion system, aerodynamic and structural dynamics.

Direct Adaptive Stability & Command Augmentation of an Air-Breathing Hypersonic Vehicle Conference Paper