Apparatus and method for displaying a travel position

• US 5,266,948 A
• Filed: 11/27/1991
• Issued: 11/30/1993
• Est. Priority Date: 11/28/1990
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Matsumoto, Yoshiyuki
• Primary Examiner(s): Swarthout, Brent
• Application Number:
  US07/798,962
• Time in Patent Office: 734 Days
• Field of Search: 340/995, 340/988, 340/990, 340/905, 73/178 R, 364/449, 364/460, 364/444
• US Class Current: 340/995.22
• CPC Class Codes: G01C 21/30 Map- or contour-matching

Abstract

Disclosed is an apparatus for displaying a travel position, which, in carrying out steps of calculating X- and Y-coordinates of a current position of the moving body; renewably presents said current position on a road map indicated on a display screen; matches between a travel trace pattern formed by subsequent current positions and each road pattern on the road map; and puts the travel trace on the mated road pattern for correction of the current position of the moving body deviated from the road on the map, to determine what class of the road the moving body is running on, e.g. mountain road, superhighway or other ordinary road, and also changes the pattern matching condition to be adapted for the class of the road, as determined by a measured number of curves per unit of distance.

Claims

1. An apparatus for displaying a travel position comprising:

(a) means for detecting a running distance travelled and a running direction of a moving body;

(b) means for calculating X- and Y- coordinates of a current position of said moving body;

(c) means for renewably presenting, on a display screen, the current position of said moving body on a road map read out from a road map storage medium;

(d) means for accumulating data, in a memory device, on subsequent current positions of said moving body to form data on a travel trace;

(e) means for matching between a travel trace pattern of said moving body and a selected road pattern by means of a given algorithm;

(f) means for putting the travel trace on the road pattern for correcting the current position of said moving body deviated from the road on the map;

(g) means for determining what class of road the moving body is running on by measuring a number of curves per unit distance; and

(h) means for changing a pattern matching condition, including parameters and thresholds usable in the algorithm according to the result of a road class determination.

2. The apparatus for displaying a travel position of claim 1 further comprising:

means for selectively using a plurality of algorithms, according to a result of said road class determination, each of which includes a pattern matching condition, including parameters and thresholds set for a specific class of roads.

3. The apparatus for displaying a travel position of claim 1 further comprising:

means for selectively using a plurality of pattern matching conditions, according to a result of said road class determination, each of which includes parameters and thresholds set for a specific class of roads.

4. A machine implemented process for displaying a travel position comprising the steps of:

(a) detecting a running distance travelled and a changing direction of a moving body;

(b) calculating X- and Y- coordinates of a current position of the moving body;

(c) renewably presenting, on a display screen, the current position of the moving body on a road map read out from a road map storage medium;

(d) accumulating data, in a memory device, on subsequent current positions of said moving body to form data on a travel trace;

(e) matching between a travel trace pattern of the moving body and a selected road pattern by means of a given algorithm;

(f) putting the travel trace on the road pattern for correcting the current position of said moving body deviated from the road on the map;

(g) determining what class of road the moving body is running on by measuring a number of curves per unit distance; and

(h) changing a pattern matching condition, including parameters and thresholds usable in the algorithm according to the result of a road class determination.

5. The machine implemented process of claim 4 wherein a plurality of algorithms are selectively used according to the result of the road class determination, and further wherein each algorithm used includes a pattern matching condition, including parameters and thresholds set for a specific class of roads.

6. The machine implemented process of claim 4 wherein a plurality of pattern matching conditions is selectively used according to the result of the road class determination, and further wherein, each pattern matching condition used includes parameters and thresholds set for a specific class of roads.