Method for identifying current position of vehicle
First Claim
Patent Images
1. A method for identifying the current position of a vehicle on a road map, comprising the steps of:
- storing data on the positions of roads and intersections on a road map as map data in the form of numerical values;
detecting a traveling of a predetermined distance by the vehicle and a current azimuth of the vehicle to thereby obtain a measured portion on said road map;
calculating the distance between said measured position and the point on a road proximate to said measured position on said road map;
comparing said distance with a predetermined threshold value to judge whether or not said distance is less than said predetermined threshold value;
identifying said point as a current position on said road map when said distance is less than said predetermined threshold value;
judging whether or not the vehicle has curved when said distance is not less than said predetermined threshold value; and
carrying out an intersection loading to coincide said measured position of the vehicle with the intersection proximate to said measured position when it is judged that the vehicle has curved.
1 Assignment
0 Petitions
Accused Products
Abstract
A momentarily changing position of a travelling vehicle is correctly identified by a vehicular nagivation system on which a magnetism sensor, angular velocity sensor, travel distance sensor and global positioning system are mounted. The current position of the vehicle is identified by, for example, storing data of a road on a map in the form of numerical values, measuring a predetermined distance which the vehicle has travelled and computing the current position on the road based upon the predetermined distance thus measured.
112 Citations
5 Claims
-
1. A method for identifying the current position of a vehicle on a road map, comprising the steps of:
-
storing data on the positions of roads and intersections on a road map as map data in the form of numerical values; detecting a traveling of a predetermined distance by the vehicle and a current azimuth of the vehicle to thereby obtain a measured portion on said road map; calculating the distance between said measured position and the point on a road proximate to said measured position on said road map; comparing said distance with a predetermined threshold value to judge whether or not said distance is less than said predetermined threshold value; identifying said point as a current position on said road map when said distance is less than said predetermined threshold value; judging whether or not the vehicle has curved when said distance is not less than said predetermined threshold value; and carrying out an intersection loading to coincide said measured position of the vehicle with the intersection proximate to said measured position when it is judged that the vehicle has curved. - View Dependent Claims (2, 3, 5)
-
-
4. A method for identifying the current position of a vehicle on a road map, comprising the steps of:
-
storing data on the positions of roads traveling distances, azimuths, and intersections on a road map as map data in the form of numerical values; detecting a traveling of a predetermined distance by the vehicle and a current azimuth of the vehicle to thereby obtain a measured portion on said road map; calculating the distance between said measured position and the point on a road proximate to said measured position on said road map; comparing said distance with a first predetermined threshold value to judge whether or not said distance is less than said predetermined threshold value; identifying said point as a current position on said road map when said distance is less than said first predetermined threshold value; obtaining a distance correcting coefficient for correcting an error of the detected traveling distance of the vehicle and an azimuth correcting coefficient for converting the detected current azimuth into the corresponding azimuth in said road map; and comparing the detected traveling distance of the vehicle from a previously-identified intersection and the detected current azimuth with the corresponding traveling distance and azimuth in said map data each time an intersection is detected or the vehicle travels at a predetermined distance to thereby update said distance correcting coefficient and said azimuth correcting coefficient.
-
Specification