| 摘要 |
PURPOSE:To make it possible to correct the present position of a vehicle by reading the vehicle position data which were outputted in the past from a buffer memory, reproducing the vehicular swept path from the past time to the present, and comparing the locus with the path pattern on a road map. CONSTITUTION:The past vehicle position data are read out of a buffer memory 3. The running locus is reproduced based on the read vehicle position data and compared with a locus on a road map. When the result agrees with the degree for satisfying a specified evaluating reference, the present position of the vehicle which is outputted from a locator 1 is corrected. Namely, the locator 1 counts the numbers of output signals from, e.g. a wheel-speed sensor 11 and obtains the number of rotations of the left and right wheels. The counted data are multiplied by the specified constant indicating the running distance per count in a multiplier, and the running distance per unit time is computed. At the same time, the relative change in bearing is obtained based on the difference in pulse numbers of the left and right wheels. A bearing signal is obtained with a geomagnetism sensor 12 and the relative change, and the bearing of the vehicle is computed. |
