Navigation system

• US 20030220735A1
• Filed: 04/23/2003
• Published: 11/27/2003
• Est. Priority Date: 04/25/2002
• Status: Active Grant

• Current Assignee: Aisin AW Company Limited (Aisin Corp.)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.)
• Inventors: Nimura, Mitsuhiro
• Granted Patent: US 6,937,936 B2
• Time in Patent Office: Days
• US Class Current: 701/208
• CPC Class Codes: G01C 21/3878 Hierarchical structures, e.g. layering
• CPC Class Codes: G09B 29/10 Map spot or coordinate position indicators; Map reading aids optical projection apparatus per se G03B

Abstract

The map data may be updated on a specified area basis. This may shorten the time for updating the map data as well as lowers the cost of map data update. A navigation system comprising a data center 51 for distributing map data about a designated area upon receipt of a data-distribution request; an on-board device 14 having a data storage that stores map data, for updating the map data about the designated area with new map data distributed from the data center; and wherein the map data distributed from the data center has a layered structure in which the map data in a lowest-layer represents the designated area while the map data in a higher-layer represents a wider area that includes a smaller area represented by a lower-layer map data.

Claims

1. A navigation system, comprising:

a data center for distributing map data about a designated area upon receipt of a data-distribution request; and

an on-board device having a data storage of map data, for updating the map data about the designated area with new map data distributed from the data center, wherein the map data distributed from the data center has a layered structure in which the map data in a lowest-layer represents the designated area while the map data in a higher-layer represents a wider area that includes a smaller area represented by a lower-layer map data.

2. A navigation system according to claim 1, wherein the data storage stores both updated map data and pre-update map data.

3. A navigation system according to claim 2, further comprising an operator terminal whereby the data-distribution request is sent to the data center and thereupon the map data is downloaded from the data center to an external storage medium.

4. A navigation system according to claim 2, wherein the data-distribution request is sent to the data center from the on-board device and the map data is downloaded directly to the data storage of the on-board device.

5. A method of operating a navigation system comprising:

determining a present position of a vehicle;

selecting an actual destination;

determining the location of the destination within stored map data;

determining, based on the stored map data, a route beginning at the present position and ending at the determined location of the destination;

communicating the route to a user of the navigation system, wherein the stored map data may be updated at the user'"'"'s request in portions smaller than the whole of the stored map data.

6. The method of operating a navigation system of claim 5, wherein the stored map data has a layered structure in which the map data in a lowest-layer represents the smallest and most detailed portions while the map data in a higher-layer represents a less detailed, wider portion(s) that include(s) a smaller area represented by a lower-layer map data portion.

7. The method of operating a navigation system of claim 6, wherein the map data may be periodically updated by a data center.

8. The method of operating a navigation system of claim 7, further comprising updating the stored map data for at least one data portion within at least one layer by receiving new data from the data center.

9. The method of operating a navigation system of claim 8, further comprising connecting the updated at least one data portion within the at least one layer to the adjacent map data of that at least one layer that is of the same version, wherein the connected data may still be reconnected to another adjacent area.

10. The method of operating a navigation system of claim 9, wherein if the determined destination is determined based on the lowest-layer map data the determined destination is the actual destination.

11. The method of operating a navigation system of claim 9, wherein if the determined destination is determined based on a layer other than the lowest-layer map data, the determined destination is a destination on a road within that other than the lowest-layer map data closest to the actual destination.

12. The method of operating a navigation system of claim 11, wherein the route is communicated visually.

13. The method of operating a navigation system of claim 12, wherein the route is communicated audibly.

14. A method of communicating the route using the navigation system of claim 6, comprising:

determining whether the present position is within a latest-version of a lowest-layer stored map data portion;

determining whether the actual destination is within a latest-version of a lowest-layer stored map data portion;

determining whether at least one of the higher-layers containing the present position is within a latest-version of the stored map data;

determining whether at least one of the higher-layers containing the actual destination is within a latest-version of the stored map data;

15. The method of communicating the route of claim 14, wherein;

if the present position is within the latest-version of a lowest-layer stored map data portion, further comprising communicating as much of the route that may be communicated based on that latest-version of the lowest-layer stored map data portion;

or

if the present position is not within the latest-version of the lowest-layer stored map data portion, further comprising communicating as much of the route that would have been within the latest-version of the lowest-layer stored map data portion based on a higher-layer that is of the latest version and contains the present position;

if the actual destination is within the latest-version of a lowest-layer stored map data portion, further comprising communicating as much of the route that may be communicated based on that latest-version of that lowest-layer stored map data portion;

or

if the actual destination is not within the latest-version of a lowest-layer stored map data portion, further comprising communicating as much of the route that would have been within that latest-version of that lowest-layer stored map data portion based on a higher-layer that is of the latest version and contains the determined destination; and

communicating as much of the determined route that traverses stored map data portions containing neither the present position nor the actual destination, by using the lowest of the layered portions which the route traverses that are of the latest-version.

16. The method of communicating the route of claim 14, wherein;

if the present position is within the latest-version of a lowest-layer stored map data portion, further comprising determining and communicating as much of the route that may be communicated based on that latest-version of that lowest-layer stored map data portion;

or

if the present position is not within the latest-version of a lowest-layer stored map data portion, further comprising determining and communicating as much of the route that may be communicated based on a lower-layer stored map data portion which contains the present position and is not of the latest-version;

if the actual destination is within the latest-version of a lowest-layer stored map data portion, further comprising communicating as much of the route that may be communicated based on that latest-version of that lowest-layer stored map data portion;

or

if the actual destination is not within the latest-version of a lowest-layer stored map data portion, further comprising determining and communicating as much of the route that may be communicated based on a lower-layer stored map data portion which contains the actual destination and is not of the latest-version; and

communicating as much of the determined route that traverses stored map data portions containing neither the present position nor the actual destination, by using a lower-layer portion which the route traverses regardless of that portions version, wherein whenever the determined route crosses a boarder between lower-layer stored map data portions that are of differing versions, the route must be re-determined and re-communicated according to the version of the lowest-layer map data portion that was crossed into.

17. The method of communicating the route of claim 16, wherein lowest-layer stored map data portions of different versions are communicated such that the data communicated from a lowest-layer map data portion of one version is distinguishable from a lowest-layer map data portion of another version.

18. A method of communicating the route using the navigation system of claim 6, wherein:

if each lowest-level map data portion necessary to determine a route from the present position to the actual destination is of the latest-version, the route is determined an communicated using those latest-version lowest-level map data portions;

or

if each lowest-level map data portion necessary to determine a route from the present position to the actual destination not of the latest version, the user may select a version of map data portions that will be used to determine and communicate the route, wherein if a map data portion of that version does not exist for a portion of the determined route a most-recent stored map data portion will be used for that non-existent portion and whenever the determined route crosses a boarder between stored map data portions that are of differing versions, the route must be re-determined and re-communicated according to the version of the map data portion that was crossed into.

19. The method of communicating the route of claim 18, wherein lowest-layer stored map data portions of different versions are communicated such that the data communicated from a lowest-layer map data portion of one version is distinguishable from a lowest-layer map data portion of another version.

20. A program embodied in a recording medium or dedicated circuit comprising the following subroutines:

a subroutine that determines a starting point of a vehicle;

a subroutine that determines a finishing point of a vehicle;

a subroutine that determines a route between the starting point and the finishing point, based on stored map data; and

a subroutine that updates the stored map, wherein the data to may be updated in portions smaller than a whole of the data.

21. A navigation system, comprising:

a data center for distributing map data in portions smaller than the whole;

an on-board device having a data storage of map data, for updating the map data about the designated area with new map data portions distributed from the data center, wherein the on-board device makes a decision whether to use updated map data or previous map data for any particular portion of route development.