Hypersonic flight conditions produce temperature variations that can alter both the structural dynamics and flight dynamics. These aerothermoelastic effects are modeled by a nonlinear, temperature-dependent, parameter-varying state-space representation. The model includes an uncertain parameter-varying state matrix, an uncertain parameter-varying nonsquare (column-deficient) input matrix, and a nonlinear additive bounded disturbance. A Lyapunov-based continuous robust controller is developed that yields exponential tracking of a reference model, despite the presence of bounded nonvanishing disturbances. Simulation results for a hypersonic aircraft are provided to demonstrate the robustness and efficacy of the proposed controller.

No abstract

Structural damage resulting from the tremondous heating incurred during hypersonic flight is mitigated by a thermal protection system; however, such mitigation is accompanied by an increase in weight that can be prohibitive. The actual design of a thermal protection system can be chosen to vary the level of heating reduction, and associated weight, across the structure. This paper considers how such designs and resulting thermal gradients influence the ability to achieve closed-loop performance. A control architecture is used that damps any thermal effects for a range of temperature profiles. Various designs are considered for a representative model to show the large variation in flight dynamics. The resulting closedloop performance is characterized as a function of the induced thermal gradients to indicate the optimality of the designs.

No abstract

No abstract