Method for making available route data for a navigational device

• US 7,110,879 B2
• Filed: 12/16/2002
• Issued: 09/19/2006
• Est. Priority Date: 12/18/2001
• Status: Active Grant

• Current Assignee: Tomtom Global Content B.V (TomTom NV)
• Original Assignee: Robert Bosch GmbH
• Inventors: Draeger, Gerd, Friedrichs, Arne, Skwarek, Volker
• Primary Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US10/320,024
• Publication Number:
  US 20030158652A1
• Time in Patent Office: 1,373 Days
• Field of Search: 701/202, 701/201, 701/204, 701/208, 701/209, 701/211, 340/995.12, 340/995.19, 340/995.23
• US Class Current: 701/202
• CPC Class Codes: G01C 21/3415 Dynamic re-routing, e.g. recalculating the route when the user deviates from calculated route or after detecting real-time traffic data or accidents
• CPC Class Codes: G01C 21/3446 Details of route searching algorithms, e.g. Dijkstra, A*, arc-flags, using precalculated routes

Abstract

For the purpose of making available route data for a navigational device, an overall route is divided up into route segments which each include a part of the overall route. A first route segment is transmitted to the navigational device, upon its request, which around the starting point includes a starting field including a plurality of possible routes, as well as a main route to an intermediate destination. Before the intermediate destination is reached, a further route segment is transmitted to the navigational device, which includes a plurality of possible routes around the intermediate destination as its starting field, as well as a main route to an additional intermediate destination or to the destination itself. The latter step is repeated for route segments for further intermediate destinations until the destination is reached.

Claims

1. A method for making available route data for a navigational device, comprising:

dividing up a route from a starting point to a destination requested by the navigational device into a plurality of route segments each including a part of the route;

transmitting a first route segment to a navigational unit of the navigational device upon request, the first route segment including a starting field around the starting point, the starting field including a plurality of possible routes and a main route to an intermediate destination on the route to the destination;

transmitting a second route segment, before the intermediate destination is reached, to the navigational unit of the navigational device, the second route segment including a plurality of possible routes around the intermediate destination as a starting field and a main route to one of an additional intermediate destination on the route to the destination and the destination; and

repeating the second route segment transmitting step for additional route segments for additional intermediate destinations until the destination is reached.

2. The method of claim 1, further comprising selecting the intermediate destination of a route segment within a starting field of a subsequent route segment.

3. The method of claim 1, further comprising:

transmitting to the navigational device as additional information at least one of a travel time and a distance to the starting point to at least one of at least one intermediate destination and the destination.

4. The method of claim 1, further comprising determining the starting field for the route segment with respect to one of information content of the route segment and a size of the route segment by at least one of a position finding quality, a positioning accuracy, a shape of the starting field, a circumference of the starting field, a diameter of the starting field and a radius of the starting field.

5. The method of claim 1, further comprising transmitting, in response to a follow-on request of the navigational device to a server, a plurality of parameters that influence a routing algorithm so that a route starting from an intermediate destination is continued exactly as computed starting from the starting point.

6. The method of claim 1, further comprising selecting a size of the starting field as a function of at least one of a vehicle speed, a street classification, a position-finding type and a position-finding accuracy.

8. The method of claim 1, further comprising:

transmitting to the navigational device as additional information at least one of a travel time and a distance from the starting point to at least one of at least one intermediate destination and the destination.

9. The method of claim 1, further comprising:

transmitting to the navigational device as additional information at least one of a travel time and a distance from the intermediate destination to at least one of the starting point and the destination.

10. The method of claim 1, wherein the route segments are loaded into a volatile memory by a CD-ROM.

11. The method of claim 1, wherein each intermediate destination lies on a main route from the starting point to the destination.

12. The method of claim 1, wherein each of the route segments includes at least one of a map geometry, driving instructions, and travel times.

13. The method of claim 1, wherein each of the route segments is restricted to at least one of a maximum available memory of the navigational device, a maximum length, a maximum travel time, and a maximum fuel usage.

14. The method of claim 1, wherein each starting field includes additional starting points, and wherein the possible routes include routes from each of the additional starting points.

15. The method of claim 1, further comprising:

performing map matching after a segment of the plurality of segments is loaded.

7. A method for making available route data for a navigational device, comprising:

dividing up a route from a starting point to a destination requested by the navigational device into a plurality of route segments each including a part of the route;

transmitting a first route segment to a navigational unit of the navigational device upon request, the first route segment including a starting field around the starting point, the starting field including a plurality of possible routes and a main route to an intermediate destination on the route to the destination;

transmitting a second route segment, before the intermediate destination is reached, to the navigational unit of the navigational device, the second route segment including a plurality of possible routes around the intermediate destination as a starting field and a main route to one of an additional intermediate destination on the route to the destination and the destination;

repeating the second route segment transmitting step for additional route segments for additional intermediate destinations until the destination is reached; and

providing an advisory notice on a display unit during a time period of loading a route segment into a display unit of the navigational device that no navigation is occurring.