Method for locating road shapes using erroneous map data
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.
1. A method for identifying a location of a road segment in digital maps, each map containing errors inherent in the reduced-scaling of the digital maps and/or depending on the kind of the digital maps, the digital maps including a first digital map and a second digital map, the second digital map showing the road segment at a different location from the first digital map due to the errors, the first digital map being stored in a transmitting apparatus, the second digital map being stored in a receiving apparatus, the method comprising the steps of:
creating location information based on the first digital map by the transmitting apparatus, the location information including: a string of coordinates of points which represents a first road shape of the road segment on the first digital map, and attribute information about the points or the road segment;
transmitting the location information from the transmitting apparatus to the receiving apparatus;
receiving the location information by the receiving apparatus;
selecting from one or more road shapes on the second digital map a second road shape which is most closely matched with the first road shape specified by the received location information; and
identifying the location of the road segment on the second digital map as the location of the second road shape.
2. The method according to claim 1 , wherein the attribute information includes at least one information item chosen from a group consisting 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.
3. A transmitting apparatus for providing location information to a receiving apparatus for identifying a location of a road segment in digital maps, each map containing errors inherent in the reduced-scaling of the digital maps and/or depending on the kind of the digital maps, the digital maps including a first digital map and a second digital map, the second digital map showing the road segment at a different location from the first digital map due to the errors, the transmitting apparatus comprising:
the first digital map;
an information generator that generates, based on the first digital map, location information including: a string of coordinates of points which represents a first road shape of the road segment on the first digital map, and attribute information about the points or the road segment; and
a transmitter that transmits the location information from the transmitting apparatus to the receiving apparatus.
4. A receiving apparatus for receiving location information from a transmitting apparatus for identifying a location of a road segment in digital maps, each map containing errors inherent in the reduced-scaling of the digital maps and/or depending on the kind of the digital maps, the digital maps including a first digital map and a second digital map, the second digital map showing the road segment at a different location from the first digital map due to the errors, the receiving apparatus comprising:
a receiver that receives the location information including: a string of coordinates of points which represents a first road shape of the road segment on the first digital map, the first digital map being stored in a transmitting apparatus, and attribute information about the points or the road segment;
the second digital map; and
an identifying unit that selects from one or more road shapes on the second digital map a second road shape which is most closely matched with the first road shape specified by the received location information and identifies the location of the road segment on the second digital map as the location of the second road shape.
5. A system for identifying a location of a road segment in digital maps, each map containing errors inherent in the reduced-scaling of the digital maps and/or depending on the kind of the digital maps, the digital maps including a first digital map and a second digital map, the second digital map showing the road segment at a different location from the first digital map due to the errors, the first digital map being stored in a transmitting apparatus, the second digital map being stored in a receiving apparatus, the system comprising:
the transmitting apparatus that includes:
the first digital map;
an information generator that generates, based on the first digital map, location information including: a string of coordinates of points which represents a first road shape of the road segment on the first digital map, and attribute information about the points or the road segment; and
a transmitter that transmits the location information to the receiving apparatus; and the receiving apparatus that includes:
a receiver that receives the location information from the transmitting apparatus;
the second digital map; and
an identifying unit that selects from one or more road shapes on the second digital map a second road shape which is most closely matched with the first road shape specified by the received location information and identifies the location of the road segment on the second digital map as the location of the second road shape.
6. The transmitting apparatus according to claim 3 , wherein the attribute information includes at least one information item chosen from a group consisting 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. The receiving apparatus according to claim 4 , wherein the attribute information includes at least one information item chosen from a group consisting 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.
8. The system according to claim 5 , wherein the attribute information includes at least one information item chosen from a group consisting 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.