Methods for Combination Optimization of Flight Routes and Flight Altitude Considering Restrictions in Free Route Airspace

In order to reduce the cost of aircraft flights and air pollution emissions when flying through Free Route Airspace (FRA), methods have been developed to jointly optimize flight paths and flight altitudes. First, cost models for calculating different optimization objectives such as fuel cost, CO2 cost, contrail cost, time cost, total flight cost are proposed. Then, we improve the algorithm based on the traditional Dijkstra’s algorithm to solve the dynamic edge weight problem by taking into account the effect of the aircraft fuel consumption on the aircraft weight and the associated emission parameters. The results show that compared with the most fuel-efficient trajectory, the minimum contrail cost trajectory reduces the contrail cost by 65.65%, while the minimum emission cost trajectory reduces the contrail cost, the emission cost, and the total flight cost, respectively by 64.26%, 15.34% and 1.76%, and the minimum total flight cost trajectory reduces the contrail cost, the emission cost, and the total flight cost respectively, by 46.67%, 11.86% and 1.94%.