Route Planning Method of Low-Altitude Rescue Flight in 3D Airspace Grid

A method that is applicable to strategic initial flight path planning based on a 3D airspace grid is presented to address the problem of aviation emergency rescue flight safety in complex low altitude environment. The algorithm divides the airspace into grids to generate flight path nodes. The terrain, weather, flight rules, and aircraft performance constraints should be considered to meet the requirements of actual flight safety. An improved A* algorithm is used to search the optimal flight path based on 3D airspace grid. Two methods are proposed on the basis of a single flight track of an aircraft to resolve the multi-aircraft strategic, conflict-free flight track planning problem, which are combined with the time window principle. Finally, simulated and real data were used to validate the presented method.