| 摘要 |
PURPOSE: To carry out a route search in which the travelling azimuth of a vehicle is taken into consideration even after U-turn operation by computing a recommended route on the basis of an azimuth close to an updated travelling azimuth of the vehicle when an azimuth difference between a road azimuth and the updated travelling azimuth of the vehicle is not less than a predetermined angle. CONSTITUTION: The azimuth of a road on which a vehicle travelled when map matching is performed immediately before is read out by a control circuit 2 from a DRAM 4 and it is compared with the current travelling azimuth of the vehicle which is detected by a current position detection device 1, and the difference between two azimuths is determined as a predetermined angle, for instance, 135 deg. or more, a vehicle position where map matching is performed immediately before is adopted as a starting point, and the road azimuth of the travelling direction of the vehicle and the road azimuth of the opposite direction of the travelling azimuth of the vehicle are detected on the basis of the starting point. It is detected that the current (updated) travelling azimuth of the vehicle detected by the device 1 is close to either one of two azimuths detected before, and the closer azimuth is set as a standard azimuth for a route search, and a recommended route is computed on the basis of it. |
