| 摘要 |
PURPOSE:To make it possible to return the position of a vehicle wherein an error has occurred by erroneous map matching on a correct road. CONSTITUTION:Every time a vehicle runs by a specified distance, a primary vehicle-position computing part 5c computes the primary vehicle position by dead reconing method. A vehicle- position correcting part 5d checks map data stored in a CD-ROM 1 and performs map matching by a projecting method. Thus, the corrected vehicle position is obtained. Every time when the corrected vehicle position is obtained, an integrating part 5e integrates the corrected vector quantities. In a vehicle-position-correction permitting and prohibiting part 5f, the integrated amount is compared with the reference amount. When the integrated amount does not exceed the reference amount, the correction at this time is made effective, and the corrected vehicle position is made to be the determined vehicle position and outputted. When the integrated amount exceeds the reference amount, the correction at this time is made invalid, and the primary vehicle position before the correction is outputted as the determined vehicle position. In an initializing part 5g, the normal correcting state is discriminated based on the magnitude of the corrected amounts of three times when the corrections at the latest three times are made effective continuously. When the state is normal, the integrated amount in the integrating part 5e is initialized. |
