| 摘要 |
PURPOSE:To improve the specifying accuracy of a point on a stored road when a motor vehicle is returned to said stored road by providing means for setting a virtual node at the present position detected by a dead reckoning method when said motor vehicle is running on a road other than said stored road. CONSTITUTION:Many nodes N1, N2... are set on a road as map data to be stored in a map data memory device 13, which is then stored. At the same time, data representing the connecting relation (Fig. (b)) of these nodes are inputted. These nodes are set a predetermined distance from each other even on a crossing point, a corner and a straight road, for example, as shown in Fig. (a). While the motor vehicle is running, an operating circuit 16 judges whether the road is a stored road in the memory device 13 as road data. If the road is judged to be a road not stored in the memory device, a virtual node is set at the present position obtained by the estimating navigating method. Then, a true node when the motor vehicle is returned to a stored road is specified on the basis of the connecting relation between the virtual node and the true nodes stored in the device 13 and, the advancing direction of the motor vehicle. |
