Voronoi diagram and GIS-based 3D path planning

The integration of terrain following, terrain avoidance, threat avoidance (TF/TA
²
) is the key technique for aircrafts to achieve low altitude penetration flight. Depending on this technique, survival ability, accuracy and diversity of aerial assault have been greatly improved. In this paper, the optimal trajectory programming algorithm of TF/TA
²
has been improved, and threat avoidance has been studied. Effective route planning is very important for successful attacking the target in depth. In order to obtain an optimized 3D route under complicated terrain environment and threats of enemy firepower, a method for optimizing the route planning based on geography information system (GIS) is proposed. According to the performance of airplane, the space of 3D route searching is changed into that of 2D simply by introducing the method of GIS, since GIS is a very powerful tool in dealing with geography space information. Thus the original planning problem is simplified as an optimization searching problem in the horizontal and vertical space. Smoothing algorithm is also integrated into dynamic trajectory programming. Firstly, the whole horizontal trajectory is planned using voronoi diagram method, and then, and then, iteratively smooth gradient and curvature of terrain until it is fit for flight with the limitation of vertical trajectory. So the phenomena jumping-off from point to end-point on trajectory will be eliminated. In preflight planning phase, threat models are constructed, and weighted undirection graph is accordingly calculated on the base of Voronoi diagram. Using graph theory's shortest route search algorithm, such as Dijkstra search algorithm, the initial optimal route is found. As the initial route may include sharp angle which can not be reached by aircraft, the feasible route will be further revised with cubic spline interpolation method. The simulation results showed that: 1) the initial route planning computation could be considerably reduced using Voronoi graph which also has the quality to be easily adjusted when unexpected threat appeared, and 2) By using the GIS method which can upply feasible route planning with its enormous space analysis ability, it will sufficiently avoid new threats.