Road data generating method for use in an on-board navigation system

摘要

A road data generating method for use in an on-board navigation system. Points on roads in a map are expressed in numerical form and memorized as map data previously, and co-ordinates of the present position of the vehicle and the compass direction of the movement of the vehicle are detected and the distance to a point on a road nearest to the present position and the angle of the road at that point are determined on the basis of the map data, as decision values for the generation of road data, every time a certain distance is traveled by the vehicle. Judgment is made as to whether or not there already is registered learning data in the vicinity of the present position when the decision values exceed the predetermined values, and standard deviations of the distance and the angle with respect to the registered learning data are calculated when there is the registered learning data. The registered learning data is registered as the road data if the standard deviations are equal to or smaller than predetermined values.