Robust flight control of aircraft in the presence of uncertainties

The main objective of the paper is to design the robust algorithms for advanced aircraft. To improve dynamic performance, increase manoeuvrability, and expand an operating envelope, the robust configurations for stabilization and robust tracking of flight vehicles are proposed. We formulate criteria for quadratic stabilizability of uncertain systems via a class of linear controllers using the Hamilton-Jacobi-Bellman theory. Necessary and sufficient conditions for robustness are studied. The robust procedure is applied to the ninth-order model of the F-18 fighter aircraft. Modeling results are presented to demonstrate the dynamic performance of the resulting nonlinear closed-loop system.