| 摘要 |
PROBLEM TO BE SOLVED: To provide a map data delivery system capable of acquiring useful detailed maps at exact timing and to provide a map data acquisition apparatus on a mobile body side suitable for this system. SOLUTION: This map data acquisition apparatus is installed integrally to an onboard navigation apparatus. Route guiding along a main road is first executed by using the large-scale map stored in the navigation apparatus. The detailed map is acquired when the moving condition of the vehicle is detected and the detailed map is judged to be necessary in accordance with the moving condition. Such time is, for example, when the vehicle deviates from the set route or approaches a construction point, etc., indicated in traffic information or approaches a destination. The adequate detailed maps are acquired at the exact timing in correspondence to a change in the moving condition. |
