| 摘要 |
PROBLEM TO BE SOLVED: To suppress the quantity of road data to be recorded in an external DRAM, in a navigation device for a vehicle for acquiring the road data of a mesh where a guide route passes from DVD-ROM or the like and recording the data in the external DRAM. SOLUTION: When a temporary guide route to a destination enters the second adjacent mesh from the first mesh of map data and has a return part route entering the first mesh from the second mesh without passing another mesh (130, 150), the navigation device for the vehicle replaces the return part route with an alternate part route passing only the first mesh (140, 160), and selects the resultant route as the guide route (170). The device records in the external DRAM only a mesh where the guide route passes between a wide-area mesh, a medium-area mesh and a detailed mesh partitioned in each hierarchy of the map data having a hierarchical structure. COPYRIGHT: (C)2007,JPO&INPIT |
