| 摘要 |
PURPOSE:To improve the correction accuracy of a vehicle position by map matching by correcting a vehicle azimuth. CONSTITUTION:Every time a distance sensor 4 detects a constant-distance travel, a vehicle azimuth calculation part 5d integrates an azimuth change detected by a relative azimuth sensor 3 to the vehicle azimuth in a vehicle azimuth memory 5c to find a new vehicle azimuth and rewrite the memory 5c, and a primary vehicle position calculation part 5d finds position variation by using the found vehicle azimuth and adds it to a last determined vehicle position to calculate a primary vehicle position; every time the primary vehicle position is found, a vehicle position correction part 5f searches for a matching candidate road by referring to map data and corrects the primary vehicle position on the road as a determined vehicle position. When the vehicle position is corrected, a decision part 5g decides whether or not the corrected link of the vehicle position is at longer than a constant distance by referring to the map data and when so, a vehicle azimuth correction part 5j finds the azimuth of the corrected ling and rewrites the memory 5c with the azimuth. |
