Rapid Altitude Tracking for Air-Breathing Hypersonic Vehicle with Limited Angle of Attack

This paper focuses on the altitude tracking issue for air-breathing hypersonic vehicles. It proposes a rapid altitude tracking method with synthetical consideration on the angle of attack constraint, which is crucial to keep the scramjet away from the inlet unstart. For the inner-loop, the novel compensator is considered in the conjunction of the backstepping approach to design a flight path angle tracking controller. The compensator helps the controller to limit the angle of attack with the uncertainties. For the out-loop of the control system, the altitude controller involves the combination of Bang-Bang control and the sliding mode technique to generate the command which accommodates the constraint on the angle of attack. The atmosphere density model is taken into account, which makes the proposed method more adaptable to the altitude variation. The effectiveness of the proposed control method is evaluated in the simulations.