Mixed H 2 /H ∞ decentralized fuzzy tracking control design for a flexible air-breathing hypersonic vehicle

This article addresses the problem of mixed H2/H∞ decentralized fuzzy tracking control design for a flexible air-breathing hypersonic vehicle, which includes the intricate coupling between the engine and flight dynamics as well as the complex interplay between the flexible and rigid modes. Initially, the nonlinear longitudinal model of the flexible air-breathing hypersonic vehicle is represented as a nonlinear large-scale interconnected system, which can be described by a Takagi–Sugeno fuzzy model. Then, based on the decentralized Takagi–Sugeno fuzzy model, a mixed H2/H∞ decentralized fuzzy tracking controller is developed to not only ensure the stability of the whole nonlinear interconnected system but also achieve the suboptimal H2 control performance under a desired H∞ disturbance attenuation level. Furthermore, the problem of mixed H2/H∞ decentralized fuzzy tracking control design is characterized in terms of a set of linear matrix inequalities. Finally, simulation results on the flexible air-breathing hypersonic vehicle demonstrate the effectiveness and merit of the proposed design method.