Direct adaptive type-2 fuzzy logic control of a generic hypersonic flight vehicle

A direct adaptive type-2 fuzzy logic controller is designed in this paper. The longitudinal dynamics of a generic hypersonic flight vehicle is high-order, highly nonlinear, tight coupling and most of all includes big uncertainties. The computing of the dynamic inversion control signal is cost ineffective and an adaptive interval type-2 fuzzy logic system is used to approximate it. A H_∞ controller is implemented in order to attenuate the fuzzy approximation error and the system uncertainty. Signals´ high-order derivatives are obtained by tracking differentiators and nonlinear state observers. The closed-loop stability is guaranteed by Lyapunov theory. Simulation results validate the effectiveness and robustness of the proposed controller.