Adaptive Type-2 Fuzzy Control For Flexible Air-Breathing Hypersonic Vehicles With Measurement Noises

This paper proposes an adaptive type-2 fuzzy control scheme for the longitudinal dynamics of flexible air-breathing hypersonic vehicles (FAHVs) with measurement noises. The proposed robust control scheme is composed of three parts, i.e. state estimators, altitude controller and velocity controller. Firstly, the dynamic model of hypersonic vehicles is analyzed and a control-oriented uncertainty model is built for later control scheme design. Then the new interval type-2 fuzzy logic system (IT2-FLS) based state estimators and controllers are designed sequentially. IT2-FLS is used to tackle unknown dynamics of the vehicles and the new state estimators are designed to estimate the real states from the measurement states which are contaminated by Gaussian white noises. Next, by backstepping control approach, the altitude controller and velocity controller are constructed to deal with the tracking problem for commanded velocity and altitude. In addition, the stability of the closed-loop systems is explored. Finally, simulation results verify the proposed control scheme which can achieve the desired velocity and altitude tracking performances in the presence of measurement noises.