Research On Auxiliary Guidance Technology For Low Level Flight

Auxiliary guidance technology for low level flight plays an important role inensuring the safety of low level flight and improving the mission success rate of lowlevel flight. In this paper, we make relevant research on auxiliary guidance technologyfor low level flight. Aimed to three key problems: threat warning technology, terrainvisibility computation and mission trajectory planning, we mainly do these jobs:(1) Research on a threat warning technology. Aimed to dangerous terrain warning,we generate terrain safety surface by dealing digital map with terrain gradient limit andterrain curvature limit, provide a dangerous terrain warning approach based on3D scene.We add a converse check step into both terrain gradient limit algorithm and terraincurvature limit algorithm. The modified algorithm is more competitive in efficiencythan original one. Aimed to dangerous object warning, we provide a dangerous objectwarning approach based on2D threat map. Taking both dangerous terrain anddangerous object into consideration, we equalize dangerous object to mountain,generate threat degree surface. Add threat degree surface to terrain safety surface, wecan get comprehensive safety surface. At last, a threat warning approach based oncomprehensive safety surface is provided.(2) Make an improvement on terrain visibility computation algorithm. This paperanalyses the computation unbalance of the LOS (line of sight) algorithm in visibilitycomputation field, presents a level based approach, which improves the original LOSalgorithm. Our approach divides the terrain into several parts, makes the visibilitycomputation relatively balance in space. Compared with incremental terrain visibilitycomputation, our approach is faster.(3) We do a lot of research on multi-object mission trajectory planning based onAnt Colony Algorithm (ACA). Different from general trajectory planning that findoptimal path from start point to end point, we set several object area need to reconnoitre.Then regard threat degree, terrain covering degree and path length as the performanceindex of trajectory. At last, apply Ant Colony Algorithm to find an optimal trajectorythat not only can ensure the safety of flight, but also can satisfy multi-objectreconnaissance requirements.(4) Design the framework of low level flight auxiliary guidance prototype system.Our framework has five modules: threat warning module, terrain visibility computationmodule, mission trajectory planning module, flight simulation module and auxiliaryguidance module. The workflow of each module and the interactive mode is described.The framework of low level flight auxiliary guidance prototype system is shown at last.