Patent ID: 6256579
Filing Date: 2001-07-03
Classification: G01C

Abstract:
A vehicle navigation system that calculates an optimum route between two geographical points designated as a starting point and a destination point, said navigation system comprising:(a) at least one data table containing sets of road data each set representing characteristics of one road segment,(b) at least one coefficient table containing a set of coefficients each coefficient corresponding to one road segment, and(c) means for searching said optimum route between said two geographical points, using modified road data that are obtained by weighting said road data by said coefficients;wherein said navigation system further comprises a history table storing geographical points designated in the past as a starting point or a destination point, and said optimum route is calculated, using both said modified road data and said road data, said modified road data being used to search an area within a certain distance of either or each of two newly designated geographical points when either of the points is already stored in said history table, and said road data being used to search areas other than the area searched with said modified road data.