| 摘要 |
PROBLEM TO BE SOLVED: To facilitate the grasping of the position relationship between own- vehicle position in a running route section and the entire route by retrieving the information of a global edge, which is to become the target of the advancing direction of own vehicle in running, and displaying the information on a map. SOLUTION: A global-edge retrieving part 11 extracts and displays a global edge, taking into consideration of the distance, at which the global edge can be seen, and the level of easy observation with regard to the running route, selected with a running-route searching part 4 based on the data of a global edge database. At first, the entire running route to the destination is set to be the running route for computation and read out of the database 10. The global edges, the passing section area and each region are retrieved. Then, the global edge, where the effectiveness becomes a maximum, is extracted. When there is no running section area region, wherein the extracted global edge is not recognized, the entire global edge is set to be the global edge in the respective object section. When there is a running section, wherein the global edge is not recognized, the computation is performed again with the section as the object. |
