Abstract:

A flight control system is developed for an aircraft performing poststall maneuver. The methods of nonlinear dynamic inversion and structured singular value synthesis are combined to address both the nonlinearity and robustness problems of flight at poststall maneuver conditions. The purpose of the nonlinear dynamic inversion control is to linearize the highly nonlinear vehicle response at poststall maneuver conditions. Structured singular value synthesis is used to design an robust controller for the linearized fast inversion loop, which provides robust tracking to pilot commands. The resulting flight control system achieves desired flying qualities and guarantees good robustness to uncertainties induced by unsteady aerodynamics effects in poststall maneuvering. This is demonstrated by high fidelity nonlinear simulation results.

Key words: structured singular value synthesis, nonlinear dynamic inversion, flight control system, robustness, poststall maneuver