Patent ID: 6078865
Filing Date: 2000-06-20
Classification: G01C

Abstract:
A navigation system which guides a mobile unit through a route to a destination, comprising:a road map database containing road map data and landmark data on landmark candidates at each crossing in a road map expressed by the road map data;a landmark table describing priority of each type of landmark candidates expressed by the landmark data;landmark selection means for detecting landmark candidates at the crossing where the mobile unit on the route is going to enter based on the road map data and the landmark data, and for selecting a landmark candidate as a landmark from the detected landmark candidates based on the landmark table, wherein said landmark candidate selected as a landmark has the highest-priority type among the detected landmark candidates;guidance means for providing guidance information by referencing the selected landmark candidate as a landmark and the route;decision means for determining whether a current time is in the daytime or in the nighttime; andchanging means for changing the priority of each type of the landmark candidates described in said landmark table according to decision of the decision means.