Design of nonlinear control laws for high-angle-of-attack flight

Abstract

High-angle-of-attack flight control laws are developed for a supermaneuvera ble fighter aircraft. The methods of dynamic inversion and structured singular value synthesis are combined into an approach which addresses both the nonlinearity and robustness problems of flight at extreme operating conditions. The primary purpose of the dynamic inversion control elements is to linearize the vehicle response across the flight envelope. Structured singular value synthesis is used to design a dynamic controller which provides robust tracking to pilot commands. The resulting control system achieves desired flying qualities and guarantees a large margin of robustness to uncertainties for high-angle-of-attack flight conditions. High-fidelity nonlinear simulation results show that the combined dynamic inversion /structured singular value synthesis control law achieves a high level of performance in a realistic environment.