Flight control design using non-linear inverse dynamics

Abstract

Aircraft in extreme flight conditions can encounter severe non-linear effects generated from high angles of attack and high angular rates. Flight control systems based upon non-linear inverse dynamics offer the potential for providing improved levels of safety and performance in these flight conditions over the competing designs developed using linearizing assumptions. Inverse dynamics are generated for specific command variable sets of a 12-state non-linear aircraft model to develop a control system which is valid over the entire flight envelope. Detailed descriptions of the inertial dynamic and aerodynamic models are given, and it is shown how the command variable sets are altered as a function of the system state to add stall prevention features to the system. Simulation results are presented for various mission objectives over a range of flight conditions to confirm the effectiveness of the design.