Digital map position information transfer method

• US 20030109984A1
• Filed: 10/16/2002
• Published: 06/12/2003
• Est. Priority Date: 04/27/2001
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Adachi, Shinya
• Granted Patent: US 6,920,392 B2
• Time in Patent Office: Days
• US Class Current: 701/208
• CPC Class Codes: G01C 21/30 Map- or contour-matching
• CPC Class Codes: G09B 29/106 using electronic means

Abstract

It is an object of the invention to provide a method of transmitting position information of a digital map which can enhance matching precision on a receiving side.

The invention provides a method of transmitting position information of a digital map in which a transmitting side transmits a vector shape on the digital map and a receiving side specifies the vector shape on a self-digital map by map matching, wherein the transmitting side selects a portion in which a plurality of candidate points are generated with difficulty during the map matching as an endpoint of the vector shape and transmits the vector shape having the endpoint in the portion to the receiving side. Mismatching on the receiving side can be prevented and the position information on the digital map can be transmitted accurately.

Claims

1. A method of transmitting position information of a digital map for transmitting a vector shape on the digital map from a transmitting side and specifying the vector shape on a digital map in a receiving side by map matching at the receiving side, the method comprising the steps of:

selecting a portion in which a plurality of candidate points are generated with difficulty during the map matching as an endpoint of the vector shape; and

transmitting the vector shape having the endpoint in the portion to the receiving side,

wherein the steps of the selecting and transmitting are executed at the transmitting side.

2. A method of transmitting position information of a digital map for transmitting a vector shape on the digital map from a transmitting side and specifying the vector shape on a digital map in a receiving side by map matching at the receiving side, the method comprising the steps of:

setting a plurality of candidate points for an endpoint of the vector shape,

drawing a perpendicular on a vicinal vector shape from each of the candidate points,

calculating a distance between an intersecting point and the candidate point and a difference in angle between an intercept azimuth of the intersecting point and an intercept azimuth of the candidate point, and

selecting, for the endpoint of the vector shape, a candidate point determined by a decision value including the distance and the difference in angle between the intercept azimuths as elements,

wherein the steps of setting, drawing, calculating, and selecting are executed at the receiving side.

3. A method of transmitting position information of a digital map for transmitting a vector shape on the digital map from a transmitting side and specifying the vector shape on a digital map in a receiving side by map matching at the receiving side, the method comprising the steps of:

shifting an endpoint of the vector shape to a portion in which a plurality of candidate points are generated with difficulty during map matching; and

transmitting the vector shape having an endpoint position deformed to the receiving side,

wherein the steps of shifting and transmitting are executed at the transmitting side.

7. The method of transmitting position information according to any of claims 3 to 6, further comprising the step of:

transmitting, to the receiving side, information about a distance error or a direction error which is obtained in the deformation of the vector shape together with the vector shape,

wherein the step of the transmitting is executed at the transmitting side.

8. The method of transmitting position information according to claim 7, further comprising the step of

ascertaining whether or not an error between the vector shape on a digital map in the receiving side specified by map matching and a received vector shape is included in a range of the error transmitted from the transmitting side,

wherein the step of ascertaining is executed at the receiving side.

4. A method of transmitting position information of a digital map for transmitting a vector shape on the digital map from a transmitting side and specifying the vector shape on a digital map in a receiving side by map matching at the receiving side, the method comprising the steps of:

drawing a perpendicular on each of vicinal vector shapes from an endpoint of the vector shape;

calculating a distance between an intersecting point and the endpoint and a difference in angle between an intercept azimuth of the intersecting point and an intercept azimuth of the endpoint;

selecting the intersecting point based on a decision value including the distance and the difference in angle between the intercept azimuths as elements; and

shifting the endpoint in an opposite direction to the intersecting point from the endpoint,

wherein the steps of drawing, calculating, selecting, and shifting are- executed at the transmitting side.

5. A method of transmitting position information of a digital map for transmitting a vector shape on the digital map from a transmitting side and specifying the vector shape on a digital map in a receiving side by map matching at the receiving side, the method comprising the steps of:

deforming an azimuth of the vector shape at an intersection in the middle of the vector shape in such a direction as to increase an angle formed by the vector shape and a connecting vector to be connected to the vector shape when the angle is small at the intersection; and

transmitting the vector shape having the azimuth deformed to the receiving side;

wherein the steps of deforming and transmitting are executed at the transmitting side.

6. The method of transmitting position information according to claim 5, further comprising the steps of:

extracting intersection included in the vector shape,

calculating an angle formed by the connecting vector to be connected to an intersection to be noted and an intersection provided in the vicinity thereof and the vector shape and a distance between the intersection to be noted and the intersection to be connected by the connecting vector,

deciding whether or not the deformation is carried out based on a decision value including at least the angle and the distance as elements, and

deforming an azimuth of the vector shape at the intersection to be noted in such a direction as to increase the angle and deforms a position of the intersection to be noted in such a direction as to increase the distance when the deformation is to be carried out,

wherein the steps of extracting, calculating, deciding, and deforming are executed at the transmitting side.

9. A program of a transmitting device for transmitting a vector shape on a digital map which is specified through map matching by a receiving side,

wherein a computer is caused to execute:

a procedure for setting a plurality of candidate points of an endpoint of the vector shape;

a procedure for drawing a perpendicular on a vicinal vector shape from each of the candidate points, and calculating a distance between an intersecting point and the candidate point and a difference in angle between an intercept azimuth of the intersecting point and an intercept azimuth of the candidate point;

a procedure for calculating a decision value including at least the distance and the difference in angle between the intercept azimuths as elements;

a procedure for selecting a candidate point to be an endpoint of the vector shape based on the decision value; and

a procedure for generating the vector shape including the selected candidate point as an endpoint.

10. A program of a transmitting device for transmitting a vector shape on a digital map which is specified through map matching by a receiving side,

wherein a computer is caused to execute the procedures of:

drawing a perpendicular on each of vicinal vector shapes from an endpoint of the vector shape, and calculating a distance between an intersecting point and the endpoint and a difference in angle between an intercept azimuth of the intersecting point and an intercept azimuth of the endpoint;

calculating a decision value including at least the distance and the difference in angle between the intercept azimuths as elements;

selecting the intersecting point based on the decision value;

shifting the endpoint in an opposite direction to the intersecting point from the endpoint;

calculating the decision value in such a state that the endpoint is shifted;

correcting a shifting distance of the endpoint based on the decision value in such a state that the endpoint is shifted; and

a procedure for generating the vector shape including the shifted endpoint.

11. A program of a transmitting device for transmitting a vector shape on a digital map which is specified through map matching by a receiving side,

wherein a computer is caused to execute:

a procedure for extracting an intersection included in the vector shape;

a procedure for calculating an angle formed by a connecting vector to be connected to an intersection to be noted and an intersection provided in the vicinity thereof and the vector shape, and a distance between the intersection to be noted and the intersection connected by the connecting vector;

a procedure for calculating a decision value including the angle and the distance as elements;

a procedure for extracting the connecting vector based on the decision value;

a procedure for deforming an azimuth of the vector shape at the intersection to be noted in such a direction as to increase an angle formed by the connecting vector thus extracted;

a procedure for calculating the decision value in such a state that the angle is changed;

a procedure for correcting an amount of change in the angle based on the decision value in such a state that the angle is changed; and

a procedure for generating the vector shape having the angle changed.