Location detecting method
First Claim
1. A location detecting method for detecting the location of a vehicle within a predetermined area, comprising the steps of:
- outputting distance data at a predetermined interval, the distance data being representative of the distance that said vehicle has traveled;
outputting heading angle data at a predetermined interval, the heading angle data being representative of the heading angle change of the vehicle travel;
storing road map data representative of roads;
computing a present location data from said distance data and said heading angle data;
computing a first limit error (E1) and a second limit error (E2) of said present location data which are determined on the basis of errors in said distance data, in said heading angle data and in said road map data;
registering locations of all roads located within said first limit error (E1), as estimate locations;
computing a correlation coefficient for each of said registered estimate locations to each of said roads located within said first limit error, by accumulating a function having as a parameter the errors between the estimate locations to the registered roads and a location on said road map at a particular point;
selecting one of said correlation coefficients indicating the error with respect to one of said roads is smallest of the errors indicated by said correlation coefficients;
outputting as a present location one of said estimate locations corresponding to the selected one correlation coefficient; and
if any of said roads location within said first limit error (E1) do not exist, outputting as a present location said present location data computed from said distance data and said heading angle data and also registering locations on all said roads located within said second limit error (E2) as second estimate locations, and if a second one of said correlation coefficients indicating that error with respect to each said road of the registered second estimate locations is less than a predetermined value and is smallest of the errors indicated by said correlation coefficients, is obtained, then outputting as a present location one of said second estimate locations corresponding to said second correlation coefficient.
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Abstract
A location detecting method for detecting the location of a vehicle within a predetermined area, comprising the steps of: outputting distance data at every predetermined interval, the distance data being representative of the distance that a vehicle has travelled; outputting heading angle data at every predetermined interval, the heading angle data being representative of the heading angle change of vehicle travel; storing road map data representative of roads; computing a present location data from the distance data and the heading angle data; computing a first limit error (E1) and a second limit error (E2) of the present location data which are determined on the basis of errors in the distance data, in the heading angle data and in the road map data; registering locations on the roads, which roads are located within the first limit error (E1) of the present location data, as estimate locations; computing correlation coefficients respectively corresponding to the registered estimate locations; selecting a correlation coefficient whose error is smallest with respect to the road from the computed correlation coefficients; and outputting the registered estimate location corresponding to the selected correlation coefficient as a present location.
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Citations
16 Claims
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1. A location detecting method for detecting the location of a vehicle within a predetermined area, comprising the steps of:
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outputting distance data at a predetermined interval, the distance data being representative of the distance that said vehicle has traveled; outputting heading angle data at a predetermined interval, the heading angle data being representative of the heading angle change of the vehicle travel; storing road map data representative of roads; computing a present location data from said distance data and said heading angle data;
computing a first limit error (E1) and a second limit error (E2) of said present location data which are determined on the basis of errors in said distance data, in said heading angle data and in said road map data;registering locations of all roads located within said first limit error (E1), as estimate locations; computing a correlation coefficient for each of said registered estimate locations to each of said roads located within said first limit error, by accumulating a function having as a parameter the errors between the estimate locations to the registered roads and a location on said road map at a particular point; selecting one of said correlation coefficients indicating the error with respect to one of said roads is smallest of the errors indicated by said correlation coefficients; outputting as a present location one of said estimate locations corresponding to the selected one correlation coefficient; and if any of said roads location within said first limit error (E1) do not exist, outputting as a present location said present location data computed from said distance data and said heading angle data and also registering locations on all said roads located within said second limit error (E2) as second estimate locations, and if a second one of said correlation coefficients indicating that error with respect to each said road of the registered second estimate locations is less than a predetermined value and is smallest of the errors indicated by said correlation coefficients, is obtained, then outputting as a present location one of said second estimate locations corresponding to said second correlation coefficient. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification