| 摘要 |
PURPOSE:To prevent a driver from getting lost by relying on erroneous information even when the error of information on a position is large by a method wherein the difference between map data in a storage device and information on a present position is found as a measuring error range and the difference is displayed together with the present position. CONSTITUTION:As a vehicle 1 is moved, the present position of the vehicle 1 is found by a position sensor 4. In a navigation system 2, map data in a storage device 3 is compared with information on the present position in the sensor 4, and their difference is used as a measuring error. That is to say, it is found how much information on an actual position found by the sensor 4 differs substantially from road data in the storage device 3. Then, when the measuring error is small, only the present position which has been found is displayed by a mark 71 indicating the present position. When the measuring error is judged to be large, a mark 31 indicating a region which takes into consideration the measuring error by the sensor 4 and which can exist is displayed simultaneously on a map while the mark 71 indicating the present position is used as the center. |
