| 摘要 |
PURPOSE:To search the road concerned within a short time, by searching the road concerned from a road group wherein roads are grouped on the basis of the azimuth approximate to that to be detected. CONSTITUTION:Data of a plurality of groups of roads to which their distances and azimuths are given respectively and which are divided into groups for every approximate azimuth are recorded on a map data recording medium 7 of a CD-ROM. When the azimuth detected by a car speed sensor 3 for azimuth sensor4 is different from the azimuth of a road, a central processing apparatus 2 searches the road concerned from the road group wherein roads are grouped on the basis of an approximate azimuth and subjects the same to the estimated present place to the actual road. |
