Method for transmitting location information on a digital map

• US 20030154019A1
• Filed: 02/14/2002
• Published: 08/14/2003
• Est. Priority Date: 08/27/1999
• Status: Active Grant

• Current Assignee: Panasonic Automotive Systems Company of America (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Yamada, Naoki, Ichikawa, Yukio, Yoshida, Seiji, Maeda, Hiroyuki, Adachi, Shinya, Miyama, Satoko, Kawasato, Takashi
• Granted Patent: US 7,634,452 B2
• Time in Patent Office: Days
• US Class Current: 701/200
• CPC Class Codes: G01C 21/34 Route searching; Route guidance
• CPC Class Codes: G08G 1/096775 where the origin of the information is a central station

Abstract

When transmitting an on-road location on a digital map, an information provider transmits, as on-road location information, string of coordinates information representing the road shape of a road section including the on-road location having a predetermined length, additional information including at least one information item chosen from a group of the attribute information on the road including the road location and detailed information on the nodes in the road section, and relative information indicating the on-road location in the road section. Receiving party receiving this on-road location information performs shape matching to identify the road section on a digital map and uses relative data to identify the on-road location in this road section. The receiving party can identify the road shape with high accuracy even when only a small amount of string of coordinates data is available. This makes it possible to reduce the data transmission amount and identify an on-load location with high accuracy.

Claims

1. A location information transmission method for reporting on-road location information on a digital map, characterized in that

an information provider reports, as on-road location information;

a string of coordinates line information representing a road shape of a road section including the on-road location having a length determined depending on difficulty of shape matching;

additional information including an information item selected from a group of attribute information on a road including said road location and detailed information on nodes in said road section; and

relative information indicating said on-road location in said road section, and that

a party that receives said on-road location information performs shape matching to identify said road section on a digital map and uses said relative data to identify the on-road location in said road section.

2. A location information transmission method according to claim 1, characterized in that a string of coordinates where coordinate data indicating the positions of the nodes and interpolation points included in said road section are arranged sequentially is used as said string of coordinate information.

3. A location information transmission method according to claim 2, characterized in that interpolation points that contribute less to shape matching are omitted out of the interpolation points included in said road section in order to generate said string of coordinate information.

4. A location information transmission method according to claim 3, characterized in that an interpolation point is omitted where a change in bearing is less than a predetermined angle with respect to bearing from an adjacent interpolation point or node and a distance from said interpolation point or node is less than a predetermined distance in order to generate said string of coordinates information.

5. A location information transmission method according to claim 2, characterized in that, as said string of coordinate information, coordinate data of a member chosen from a group of nodes and interpolation points included in said road section is represented using absolute coordinates and

that data of members of nodes and interpolation points excluding said chosen member is represented using relative coordinates.

6. A location information transmission method according to claim 1, characterized in that said additional information includes at least one information item chosen from a group of road type code, road number, toll highway code, number of traffic lanes, regulation information, road width, number of connecting links to a crossing node, and connection angle of each connecting link to a crossing node.

7. A location information transmission method according to claim 6, characterized in that said additional information includes accuracy information on a digital map data used.