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Overall design in many air-breathing hypersonic vehicles (AHSVs) uses the integrated airframe/scramjet configuration formed with elongated fuselage and light structure, resulting in intricate aerodynamic–propulsive-elastic couplings. In this paper, a high-fidelity flexible AHSV dynamic modeling procedure is proposed at first, which consists of three main parts: i) panel method based aerodynamic modeling; ii) scramjet modeling; iii) finite-element-method (FEM) based aeroelastic modeling. Unsteady and viscous effects are estimated through linear piston theory and Eckert's reference temperature method, respectively. Additional models for shock interaction, ram-to-scram transition, and finite rate chemistry reaction are also included. To overcome the intractability of physics-based model, the Morris method is applied to identify the main influence factors during surrogate modeling. Then to investigate the flexible mode effect on the stability boundary, the principle of Null-controllability region (NCR) is employed, under control input saturation and bandwidth constraints. The X-43A like air-breathing hypersonic vehicle operating at cruise condition is studied for verification purpose, and the Monte-Carlo simulation results demonstrate the effectiveness of the proposed dynamic modeling and performance limitation analysis approach. [ABSTRACT FROM AUTHOR]

Guardian maps provide a concise and practical approach to parametric robustness analysis. However, non-convexity and nonlinearity of high dimensional guardian maps restrict the application. In this paper, a closed-loop performance-oriented approach to parametric robustness analysis is proposed. First, a sufficient condition for the existence of parametric stable region satisfying the closed-loop performance is presented. To further identify the maximum stable region, a robustness criterion is provided, leading to a numerical approach for parametric stability margin. The superiority of the proposed method lies in the applicability to robust performance analysis with nonlinear high-dimensional parameters. Applications are discussed with emphasis on the flight control of hypersonic vehicles, including robust control design and robust stability analysis. Results are of significant that no prior knowledge on controller tuning is required, and parametric stability margin can be obtained automatically regardless of the dimension of parameter space. [ABSTRACT FROM AUTHOR]