Patent ID: 6023653
Filing Date: 2000-02-08
Classification: G01C

Abstract:
A vehicle position detecting apparatus comprising:road data recording means for recording road data composed of linear road portions;reading means for reading out the recorded road data from said road data recording means;present position detecting means for detecting a present position of a vehicle;vehicle bearing detecting means for detecting a progress bearing corresponding to a progress direction of the vehicle at the present position; andmap matching means for receiving outputs of said reading means, said present position detecting means, and said vehicle bearing detecting means, wherein said map matching means comprises:degree of similarity calculating means for retrieving linear road portions from the recorded road data which are close to the detected present position of the vehicle, and calculating a degree of similarity value for each of the retrieved linear road portions on the basis of the present position and the progress direction of the vehicle, wherein the degree of similarity value reflects a degree of similarity between a bearing of the retrieved linear road portion and a running history of the vehicle; andposition correcting means comprising:degree of similarity judgement means for receiving an output of said degree of similarity calculating means and for judging whether the degree of similarity value calculated for each of the retrieved linear road portions is larger than a predetermined value; andsection measurement means for receiving an output of said degree of similarity judgement means and measuring either a distance traveled by the vehicle or a time period which is passed during a period the degree of similarity value for a single retrieved linear road portion is continuously judged to be larger than the predetermined value;said position correcting means corrects the present position of the vehicle on the single retrieved linear road portion when either the measured distance is greater than a predetermined distance or the measured time period is greater than a predetermined time period.