Neighboring optimal aircraft guidance in winds

The technique of neighboring optimal control is extended to handle cases of parameter change in the system dynamic model. This extension is used to de velop an algorithm for optimizing horizontal aircraft trajectories in gener al wind fields using time-varying linear feedback gains. The minimum-time p roblem far an airplane traveling horizontally between two points in a varia ble wind field (a type of Zermelo problem) is used to illustrate how pertur bations in system parameters can be accounted for by augmenting the dynamic model with additional bias states. For the special case of a constant wind shear in the cross-track direction, analytical and numerical results are d erived for bias perturbations, Numerical simulations are presented to demon strate the performance of the proposed state-augmentation technique. An add itional example is used to demonstrate an algorithm to compute near-optimal trajectories in general wind fields, The algorithm is based on nondimensio nalizing the neighboring optimal control solutions and using piecewise line arly,varying wind and horizontal wind shear parameters. One proposed applic ation of this technique is to the computation and real-time update of time- optimal trajectories in mind fields by onboard flight management systems an d by ground-based air traffic management automation tools.