Implementation of a robust differential game based trajectory tracking approach on a realistic flight simulator

In this paper, a differential game based method is adopted for the aircraft trajectory tracking task in the presence of wind. Under this differential game based approach the trajectory tracking task for a given reference is formulated as a game between the aircraft controls (first player) and wind (second player). This method is integrated in a realistic flight simulator model including a nonlinear plant, actuator as well as sensor models by means of a cascaded control architecture. The controller, responsible for the rotation and attitude control, is based on the method of Nonlinear Dynamic Inversion (NDI). This controller is extended by a trajectory loop which allows to track reference trajectories under the consideration of external disturbances (wind) using the differential game based approach. The illustrative examples provided in this paper consider a realistic aircraft trajectory for the approach phase which, besides departure, can be considered one of the most critical phases of flight. The approach trajectory is determined based on the solution of an appropriate optimal control problem using a reduced model of the flight simulator. It is shown that the proposed approach can effectively be used for tracking trajectories without a-priori knowledge regarding the wind field.