Fuzzy guaranteed cost tracking control for a flexible air-breathing hypersonic vehicle

This study is concerned with the fuzzy guaranteed cost output tracking control design problem for a flexible air-breathing hypersonic vehicle (FAHV), which can be modelled in a Takagi-Sugeno (T-S) model form. Owing to the enormous complexity of the vehicle dynamics, only the longitudinal model is adopted for control design in the present paper. A T-S fuzzy model is first proposed to represent the non-linear dynamics of FAHV. Then, a new augmented system is developed and a fuzzy guaranteed cost output tracking control problem is studied by considering output tracking and performance cost simultaneously. A fuzzy guaranteed cost state feedback controller is designed for the obtained augmented system to guarantee that the closed-loop system is asymptotically stable and the proposed performance index has an upper bound. By utilising Lyapunov functional approach, sufficient solvability conditions for such a controller are also established in terms of linear matrix inequalities, which can be easily solved via standard numerical softwares. Numerical simulations are performed to show the excellent reference altitude and velocity tracking performance.