Inversion control of aircraft herbst maneuver with nonlinear dynamic root-finding

Root-finding techniques may be utilized in designing the controller, and the heavy numerical iteration brought by the conventional methods is unappealing. A nonlinear Dynamic Root-finding (DRF) technique is developed and embedded in the time-scale separation based Dynamic Inversion (DI) controller to realize the aircraft Herbst post-stall maneuver. Different from the conventional root-finding methods, the proposed method is derived from the dynamics stability theory. The employment of this method makes the control logic fairly simple and the resulting controller is of appealing integral form. Under reasonable assumptions, the stability of the further developed DI control system is guaranteed. Simulation results verify the DRF method's efficiency, precision and reliability in solving the state-dependent nonlinear implicit algebraic equation. This technique may be applied to other control problems.