| 摘要 |
PURPOSE: To provide a present position-calculating apparatus which can reset a running distance coefficient corrected in accordance with running of a vehicle and used for obtaining a running distance to an initial value. CONSTITUTION: An MPU 114 multiplies a count of output pulses of a velocity sensor 103 counted by a counter 116 by a running distance coefficient, thereby to obtain a running distance of a vehicle. Moreover, the MPU 114 estimates a running road where the vehicle runs and a present position of the vehicle on the road based on an advancing direction of the vehicle obtained from map data stored in a CD-ROM 105, measured values by an angular velocity sensor 101 and a bearing sensor 102, and the running distance of the vehicle. The running distance coefficient is dynamically corrected in accordance with a difference of a direction of the estimated road at the estimated present position and the advancing direction of the vehicle. When a switch 117 indicates that the estimated present position is to be corrected, the MPU 114 resets the corrected running distance coefficient to an initial value in response to the indication. |
