Map database apparatus

• US 5,928,305 A
• Filed: 04/19/1996
• Issued: 07/27/1999
• Est. Priority Date: 04/21/1995
• Status: Expired due to Term

• Current Assignee: Clarion Co., Ltd. (Faurecia SA)
• Original Assignee: Xanavi Informatics Corporation (Hitachi, Ltd.)
• Inventors: Nomura, Takashi
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US08/634,853
• Time in Patent Office: 1,194 Days
• Field of Search: 701/200, 701/201, 701/202, 701/206, 701/207, 701/208, 701/209, 701/210, 701/211, 701/212, 340/988, 340/990, 340/995, 73/178 R
• US Class Current: 701/207
• CPC Class Codes: G01C 21/387 Organisation of map data, e.g. version management or database structures

Abstract

A road on a map is expressed as link string data constituted with a plurality of links which represent minimum units of the road and nodes on a start point and an end point of the plurality of links. A map database apparatus is provided with a first storage device which stores in memory node information constituted with identifying information for identifying a plurality of links and position information of a node shared by adjacent links as map display data, and a second storage device which stores in memory home node information on an identical node, which is belonging to one link string data, with position information identical to that of a node of another link string data and adjacent node information which represents a node adjacent to the identical node in a link of another link string data to be connected to the identical node as route search information.

Claims

1. A map database apparatus, comprising a storage device in which link string data is stored, wherein:

a road on a map represented by a plurality of links and a plurality of nodes is expressed as said link string data, said links representing minimum units of said road, said nodes being at a start point and an end point of each of said plurality of links;

said link string data has node information relating to said nodes, said node information including identifying information for identifying a link connected to said node and position information related to a position of said node on the map; and

said node information is shared with adjacent links.

2. A map database apparatus according to claim 1, wherein:

said node information of said link string data is stored in a memory area of said storage device in an order such that said links are lined up in one direction to form a road on a map.

3. A map database apparatus according to claim 2, wherein:

said node information includes a storage position of immediately preceding node information so that said link string data can be read out in a direction reverse from said one direction.

4. A map database apparatus according to claim 1, wherein:

said link string data includes interpolation point position information for interpolating a link physical form by further dividing one of said links into a plurality of portions and position information on individual interpolation points is stored in a memory area of said storage device in a direction in which said links are lined up in one direction to form a road on a map.

5. A map database apparatus according to claim 4, wherein:

said interpolation point position information includes a storage position of immediately preceding interpolation point information or immediately preceding node information so that said set of link string data can be read out in a direction reverse from said one direction.

6. A map database apparatus according to claim 1, wherein:

said map is partitioned into a plurality of areas and among roads within one partitioned area, roads of identical type are grouped to constitute one of said link string data.

7. A map database apparatus according to claim 6, wherein:

said roads of identical type refer to roads assigned with an identical number.

8. A map database apparatus according to claim 6, wherein:

when two or more of said link string data are stored in memory for said one partitioned area and said link string data each have node information which has identical position information, said node information having said identical position information in said one link string data includes offset data which indicates a storage position of node information having said identical position information in another one of said link string data.

9. A map database apparatus according to claim 8, wherein:

when node information of said one link string data does not have position information identical to position information of node information of said another link string data, specific information indicating that said node information of said one link string data does not have position information identical to position information in said another link string data is stored in a memory area, in which said offset information is stored, for said node information of said one link string data.

10. A map database apparatus according to claim 1, wherein:

said node information includes traffic regulation information for links to be connected to a corresponding node.

11. A map database apparatus according to claim 1, wherein:

said node information includes road width information for links to be connected to a corresponding node.

12. A map database apparatus according to claim 1, wherein:

said node information includes number of lanes information for links to be connected to a corresponding node.

13. A map database apparatus according to claim 1, wherein:

said link string data includes altitude information indicating altitudes in said plurality of links.

14. A map database apparatus according to claim 13, wherein:

said altitude information for all of said plurality of links in one link string data is stored together in memory at an end of said set of link string data.

15. A map database apparatus according to claim 1, wherein:

said link string data are stored in memory for each of various maps at different map scales, said link string data corresponding to each other between said various maps being stored with common identifying information.

16. A map database apparatus, comprising a storage device in which route search data is stored, wherein:

a road on a map represented by a plurality of links and a plurality of nodes is expressed as link string data, said links representing minimum units of said road, said nodes being at a start point and an end point of each of said plurality of links; and

said route search data has home node information of an identical node of one of said link string data, position information of said identical node being identical to position information of a node of another one of said link string data, and adjacent node information of anode which is adjacent to said identical node, said adjacent node including a node of another one of said link string data.

17. A map database apparatus according to claim 16, wherein:

said route search data are stored in a memory area of said storage device in an order in which said plurality of links are lined up in one direction to form a road on a map.

18. A map database apparatus according to claim 16, wherein:

said adjacent node information comprises identifying information for identifying adjacent nodes and information related to links from said identical node to an adjacent node.

19. A map database apparatus according to claim 18, wherein:

said information related to links from said identical node to said adjacent node includes link cost and/or traffic regulation information.

20. A map database apparatus, in which a road on a map represented by a plurality of links and a plurality of nodes is expressed as link string data, said links represent minimum units of said road, and said nodes are at a start point and an end point of each of said plurality of links, comprising:

a first storage device which stores node information constituted with identifying information for identifying said plurality of links and position information for said nodes shared by adjacent links as map display data; and

a second storage device which stores home node information for an identical node of one of said link string data, position information of said identical node being identical to position information of nodes of another one of said link string data, and adjacent node information for representing a node adjacent to said identical node as route search information, said adjacent node including a node of another one of said link string data.

21. A map database apparatus according to claim 20, wherein:

said first storage device and said second storage device store various types of information using identifying information shared by corresponding link string data for each of various maps at different map scales.