초록 ▼

A number of navigation functions are performed on terrain navigation space. One function is to define a dynamic dangerous zone based on flight altitude by locating and aggregating, a set of nodes of terrain height over a minimum flight altitude. Algorithms such as collision check, mountainous area b

A number of navigation functions are performed on terrain navigation space. One function is to define a dynamic dangerous zone based on flight altitude by locating and aggregating, a set of nodes of terrain height over a minimum flight altitude. Algorithms such as collision check, mountainous area boundary and region growing technique are developed as basic operations for this terrain model. In addition a visibility graph approach for dynamic route selection may adapted to reduce the real-time computational requirements. This approach reduces the size of the search space by establishing a partial visibility graph of terrain and avoids details of the terrain, which do not influence the choice of flight path, independent of the size of the navigation space. By exploiting the multiple and variable resolution properties of Oct-tree terrain models, a series of CFIT warning functions using terrain data as reference are implemented efficiently with existing-on-board terrain data resources.

대표청구항 ▼

[ What is claimed is:] [1.]1. A method of performing real-time flight path selection and path planning for general aviation, comprising the following steps:using Digitized Terrain Elevation Data (DTED) to generate a terrain model, said terrain model containing a set of nodes, each of said nodes cont

[ What is claimed is:] [1.]1. A method of performing real-time flight path selection and path planning for general aviation, comprising the following steps:using Digitized Terrain Elevation Data (DTED) to generate a terrain model, said terrain model containing a set of nodes, each of said nodes containing four parameters I,J,K,S, the four parameters I,J,K,S being obtained by mapping each elevation peak point I, J, K of a DTED file into a 3-D locational code of the corresponding Oct-tree, parameters I, J defining the 2-D coordinates of planar location, with elevation K, the parameters I,J,K defining the 3-D coordinates of a space location, and a scaling factor of the elevation being introduced which divides the terrain elevation into bands, parameter K representing scaled elevation, the nodes of said Oct-tree with equal scaled value of elevation occurring in the same quadrant of the corresponding quad-tree being merged, the scaling factor also being non-linear, or beginning with a baseline instead of the mean sea level, parameter S being the coverage area of a node which is added to represent the size of a node, and bit positions of said four parameters I,J,K,S being interleaved to form an integer representation of a node;using this terrain model to provide a navigation space;accessing and retrieving terrain model to generate a terrain map;giving start and goal points on navigation space to determine a ground track of direct flight path on the terrain map;identifying a dangerous zone based on ground track and flight altitude;using said dangerous zone to allocate a set of way-points for avoidance;constructing a visibility graph of navigation space, in which is included a set of collision free path segments;linking start point to goal point by using a flight path searching algorithm; andobtaining the terrain profile of the flight path from the terrain model.