MAP DISTRIBUTION SERVER FOR AUTOMOTIVE NAVIGATION SYSTEMS, MAP DATA DISTRIBUTION SYSTEM, AND ROAD DIFFERENCE DATA PRODUCTION METHOD

• US 20140188386A1
• Filed: 12/26/2013
• Published: 07/03/2014
• Est. Priority Date: 12/28/2012
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: OBARA, KIYOHIRO
• Granted Patent: US 9,470,533 B2
• Time in Patent Office: Days
• US Class Current: 701/532
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G01C 21/367 Details, e.g. road map scale, orientation, zooming, illumination, level of detail, scrolling of road map or positioning of current position marker
• CPC Class Codes: G01C 21/3815 Road data
• CPC Class Codes: G01C 21/3878 Hierarchical structures, e.g. layering

Abstract

Automotive navigation map data has a multilevel structure in which links have a relationship of association with one another among the minutest level and upper levels that are different from the minutest level in scale. A lowermost-level translation unit uses as original data items old and new RDB-form map data items of the minutest level to produce RDB-form difference data of the minutest level. An upper-level difference translation unit produces CSV-format data of a difference of each of the levels of the multilevel structure on the basis of CSV-format data, into which the difference data of the minutest level is translated, and information on the relationship of association among the links of the upper and lower levels in the automotive navigation map data, and integrates the difference data items as final map difference data for an automotive navigation map.

Claims

1. A map distribution server that produces automotive navigation map data for automotive navigation systems, comprising:

a lowermost-level difference translation unit; and

an upper-level difference translation unit, wherein

an automotive navigation map is represented by network data in which roads are expressed with links and intersections are expressed with nodes;

automotive navigation map data has a multilevel structure in which the links are associated with one another among the minutest level and upper levels which are different from the minutest level in scale;

the lowermost-level difference translation unit uses as original data items old and new map data items of the minutest level, which are of a relational database (RDB) form, to produce RDB-form difference data of the minutest level; and

the upper-level difference translation unit produces difference data of each of the relevant levels of the multilevel structure on the basis of data, into which the difference data of the minutest level is translated, and information on a relationship of association among the links of the upper and lower levels of the automotive navigation map data, and integrates the resultant difference data items so as to produce final map difference data for the automotive navigation map.

2. The map distribution server for automotive navigation systems according to claim 1, wherein the difference data to be produced by the lowermost-level difference translation unit and the final map difference data to be produced by the upper-level difference translation unit are CSV-format data items.

3. The map distribution server for automotive navigation systems according to claim 2, wherein the RDB-form original data of the minutest level includes information concerning each of road attributes of each of the links, and the final map difference data is data produced based on a difference in a road attribute between the old and new original data items.

4. The map distribution server for automotive navigation systems according to claim 3, further comprising a storage unit, wherein:

based on a difference between the original data items of the minutest level preserved in the storage unit, the upper-level difference translation unit creates CSV-format automotive navigation map data of each of the relevant upper levels so as to produce difference data of each of the levels for the automotive navigation map.

5. The map distribution server for automotive navigation systems according to claim 4, wherein:

an ID with which a minimal component of the automotive navigation map is identified is assigned to each of the links of the multilevel structure, the link IDs are used to produce an upper/lower link association table indicating a relationship of association among the lower-level links and upper-level links of the multilevel structure, and the upper/lower link association table is preserved in the storage unit; and

for production of the difference data, the upper-level difference translation unit uses the upper/lower link association table to produce difference data items of all relevant levels of the multilevel structure for the automotive navigation map, and integrates the difference data items as final map difference data for the automotive navigation map.

6. The map distribution server for automotive navigation systems according to claim 4, wherein:

an ID with which a minimal component of the automotive navigation map is identified is assigned to each of the links of the multilevel structure, the link IDs are used to produce an upper/lower link association table indicating a relationship of association among the lower-level links and upper-level links of the multilevel structure, and the upper/lower link association table is preserved in the storage unit; and

the upper-level difference translation unit produces difference data of each of the upper levels from a link, which substantially has a difference, on the basis of a difference between the original data items of the minutest level, and integrates the difference data items as final map difference data for the automotive navigation map.

7. The map distribution server for automotive navigation systems according to claim 6, wherein for production of difference data, the upper/lower link association table is used to produce as difference data a change of an upper-level link that is associated with the changed part of a lower-level link.

8. The map distribution server for automotive navigation systems according to claim 7, wherein:

whether the difference of the upper-level link from the lower-level link is smaller than a resolution of a display unit of an automotive navigation system is decided; and

if the difference is smaller than the resolution, display of the difference of the upper level is omitted, and difference data of each of the levels for the automotive navigation map is produced.

9. The map distribution server for automotive navigation systems according to claim 8, wherein:

the original data of the minutest level includes information concerning each of a plurality of road attributes of each of the links that are the components;

the final map difference data is data based on a difference in a road attribute between the old and new original data items; and

if omission of display concerning the road attribute is inhibited, display of the difference of the upper level is not omitted but the difference data of each of the levels for the automotive navigation map is produced.

10. A map data distribution system comprising:

a map distribution server; and

an automotive navigation terminal that is provided with an automotive navigation map by the map distribution server over a network, wherein

the automotive navigation map is represented by data having a multilevel structure that includes the minutest level and upper levels which are different from the minutest level in scale;

the map distribution server includes a lowermost-level difference translation unit and an upper-level difference translation unit;

the lowermost-level difference translation unit uses as original data items two old and new map data items of the minutest level of an RDB form, which are provided by a map dealer, to produce RDB-form difference data of the minutest level;

the upper-level difference translation unit produces difference data of each of the levels of the multilevel structure on the basis of data, into which the difference data of the minutest level is translated, and information on a relationship of association among links of the upper and lower levels of the automotive navigation map data, and integrates the difference data items as final map difference data for the automotive navigation map;

in response to a map distribution request issued from the automotive navigation terminal, the final map difference data is distributed to the automotive navigation terminal; and

the automotive navigation terminal performs updating processing on the automotive navigation map on the basis of the final map difference data, which is provided by the map distribution server, and old-generation data of the automotive navigation map which the automotive navigation terminal holds.

11. The map data distribution system according to claim 10, wherein the difference data to be produced by the lowermost-level difference translation unit and the final map difference data to be produced by the upper-level difference translation unit are CSV-format data items.

12. The map data distribution system according to claim 11, wherein:

the RDB-form original data of the minutest level includes information concerning each of attributes of each of links that are components;

the map distribution server decides whether a difference of an upper-level link from the link of the minutest level is smaller than a resolution of a display unit of an automotive navigation system; and

if the difference is smaller than the resolution, the map distribution server omits display of the difference of the upper-level link, and produces difference data of each of the levels for the automotive navigation map.

13. A road difference data production method for producing automotive navigation map data for automotive navigation systems in a map distribution server,

the map distribution server including a lowermost-level difference translation unit that produces difference data of the minutest level of an RDB form, and an upper-level difference translation unit that produces difference data of each of levels of a multilevel structure, and

an automotive navigation map being represented by network data in which roads are expressed with links and intersections are expressed with nodes, and the automotive navigation map data having the multilevel structure in which the links have a relationship of association with one another among the minutest level and upper levels which are different from the minutest level in scale,

the road difference data production method comprising the steps of:

producing RDB-form difference data of the minutest level using as original data items old and new RDB-form map data items of the minutest level; and

producing as road difference data difference data items of the respective levels of the multilevel structure on the basis of data, into which the difference data of the minutest level is translated, and information on the relationship of association among the links of the upper and lower levels of the automotive navigation map data.

14. The road difference data production method according to claim 13, wherein the difference data to be produced by the lowermost-level difference translation unit and the final map difference data to be produced by the upper-level difference translation unit are CSV-format data items.

15. The road difference data production method according to claim 14, wherein the RDB-form original data of the minutest level includes information concerning each of road attributes of each of the links, and the final map difference data is data produced based on a difference in a road attribute between the old and new original data items.