3-Dimensional Flight Path Planning Of General Aviation Rescue In Complex Low-Altitude Airspace

In the earthquakes,mudslides,forest fires and a variety of rescue events disposal that have occurred,general aviation has played a key role because of its mobility,small restrictions and other characteristics.However,the current domestic general aviation rescue capability is relatively weak,mainly in the number of general aviation aircraft used for emergency rescue is relatively small,general aviation supporting equipment is insufficient,the maturity of cooperation between units to be improved,etc.And the airspace environment in which rescue aircraft operate is usually complex,with low rescue flight altitudes,large changes in terrain and intensive flight activities,and the above factors affect the safety of rescue flights.Aimed at the safety of general aviation rescue flights and the need to improve the efficiency of rescue operations,this thesis studied the path planning of general aviation for rescue operations in complex low-altitude airspace,focused on forest fire rescue scenarios.Major research efforts include:(1)In response to the problems of low rescue efficiency and weak of coordination capability revealed by the rescue through aviation,an Air-ground integrated command system model suitable for general aviation rescue was established.Based on OODA cycle theory and collaborative decision theory,an Air-ground rescue command system is designed.At the same time,based on information technology,the general aviation rescue command information system for Air-ground integrated command is designed,and the research results can provide theoretical support for the development of corresponding rescue command platforms.(2)In response to the previous static airspace segmentation model based on latitude and longitude,it is difficult to adapt to the dynamic evolution of rescue scenarios and the adjustment of rescue flight airspace occupancy requirements,a raster airspace model for complex low-altitude navigation and rescue is established.Started from the special characteristics of disaster rescue,considered the key elements information,used the rasterization method,and used the hexagonal grid as the base grid for airspace dissecting.At the same time,based on the Geo SOT grid to encode address,height and property of the grid airspace,a grid airspace model for rescue is established to lay the foundation for carrying out rescue flight path of general aviation in complex low-altitude airspace.(3)In response to the level flight problem of general aviation in rescue operations,a rescue multi-type flight path planning model and algorithm for the leveling process is established.Started from the type of general aviation rescue,the number of starting points and destinations of rescue flights is used as a basis to classify them into three types of rescue:single starting point-single target point,single starting point-multi-target point,and multi-starting point-multi-target point.To minimize the cost of disaster rescue and disaster rescue flight safety risk as the optimization goal,consider the maximum range of general aviation aircraft and other performance constraints.And based on A* algorithm,we improved from two aspects of heuristic function and search strategy design to establish a rescue path planning solution model algorithm for level flight process.(4)In response to the whole rescue process of path planning for general aviation,considered the influence of uncertainties such as disaster rescue terrain and disaster situation development on the safety of disaster rescue flights,a model and algorithm for general aviation rescue path planning for the whole process of rescue is established.Based on the optimization objectives for the leveling process,with the objectives of shortest flight time for general aviation,lowest cost for disaster rescue and minimum safety risk,a 3D path planning solution model algorithm for general aviation disaster rescue considering static obstacle avoidance is established based on RRT algorithm and improved A* algorithm.Also considered the influence of fire airflow in forest fire scenarios,a 3D path planning solution model algorithm for general aviation rescue under fire airflow avoidance is established.