| 摘要 |
PROBLEM TO BE SOLVED: To maintain the quality of a route obtained by a route search, and reduce a time required for the route search. SOLUTION: A navigation apparatus for searching the route from a departure place to a destination includes: an information storage means (3) for storing a map data having a hierarchy structure other than at least one hierarchy of the map data; a route search means (4a) for reading the hierarchically-structured map data from the information storage means, searching the route within a predetermined area at the departure place and the destination, and obtaining the shortest cost route in a range in which search areas are overlapped; and a control means (4b) for controlling the search by the route search means. The route search means expands the predetermined area to the search area at an upper hierarchy in the search of the hierarchy at which the map data of the nearest upper hierarchy does not exist, and searches it. When a cost of the shortest cost route obtained by searching it to the upper hierarchy is lower than a cost of the obtained shortest cost route, the control means updates the cost of the shortest cost route. COPYRIGHT: (C)2010,JPO&INPIT |
