SYSTEM AND METHOD FOR GEOGRAPHIC INTERPOLATION OF TRAFFIC DATA

• US 20090088963A1
• Filed: 09/28/2007
• Published: 04/02/2009
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: Xanavi Informatics Corporation (Hitachi, Ltd.)
• Original Assignee: Xanavi Informatics Corporation (Hitachi, Ltd.)
• Inventors: Kato, Manabu, Machii, Kimiyoshi, Horiguchi, Sadanori
• Granted Patent: US 8,290,699 B2
• Time in Patent Office: Days
• US Class Current: 701/200
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G08G 1/096844 where the complete route is dynamically recomputed based on new data

Abstract

A method for geographic interpolation of traffic data in a vehicle navigation system in which the navigation system includes a map database divided into geographic meshes. Each mesh includes a plurality of road links of different types. That data also includes a first set of meshes containing traffic flow data while a mutually exclusive second set of meshes contains no such traffic flow data. A border between the first and second set of meshes is first identified and thereafter a blend zone of blend meshes is created by selecting at least one mesh adjacent the border so that the blend mesh is interposed between the first and second set of meshes. Thereafter, the traffic data for each type of road link in the blend mesh is adjusted to a value intermediate the first and second set of adjacent meshes for each type of road link and the blend mesh data is then stored.

Claims

1. For use with a vehicle navigation system having a map database divided into geographic meshes, each mesh containing a plurality of road links of different types, wherein a first set of said meshes contain traffic flow data while a mutually exclusive second set of said meshes contain primarily statically preassigned speed values, a method for geographic interpolation of traffic data comprising the steps of:

identifying one or more borders between said first set and said second set of said meshes,

selecting at least one blend mesh from one of said first and second sets of meshes by selecting at least one mesh adjacent said border so that said at least one blend mesh is interposed between said first and said second set of meshes,

adjusting the traffic data for each type of road link in the at least one blend mesh to a value between adjacent meshes in said first set of meshes and adjacent meshes in said second set of meshes for each type of road link,

storing said adjusted traffic data for said at least one blend mesh.

2. The invention as defined in claim 1 wherein said at least one blend mesh is selected from said first set of meshes.

3. The invention as defined in claim 1 wherein said at least one blend mesh is selected from said second set of meshes.

4. The invention as defined in claim 1 wherein said selecting step further comprises the step of selecting a plurality of meshes adjacent each said border to form said at least one blend mesh.

5. The invention as detailed in claim 1 wherein said first set of meshes contains road link data for each type of road link which varies as a function of a further parameter and wherein said adjusting step further comprises the step of adjusting the traffic data in said at least one blend mesh as a function of said further parameter.

6. The invention as defined in claim 5 wherein said further parameter comprises time of day.

7. The invention as defined in claim 5 wherein said further parameter comprises different types of weather conditions.

8. The invention as defined in claim 1 wherein said adjusting step further comprises the step of adjusting the traffic data in said at least one blend mesh as a function of distance across said at least one blend mesh between said first and said second set of meshes.

9. A vehicle navigation system having a map database divided into geographic meshes, each mesh containing a plurality of road links of different types, wherein a first set of said meshes contain traffic flow data while a mutually exclusive second set of said meshes contain primarily statically preassigned speed values, apparatus for geographic interpolation of traffic data comprising:

means for identifying one or more borders between said first set and said second set of said meshes,

means for selecting at least one blend mesh from one of said first and second sets of meshes by selecting at least one mesh adjacent each said border so that said at least one blend mesh is interposed between said first and said second set of meshes,

means for adjusting the traffic data for each type of road link in the at least one blend mesh to a value between adjacent meshes in said first set of meshes and adjacent meshes in said second set of meshes for each type of road link,

means for storing said adjusted traffic data for at least one said blend mesh.

10. The invention as defined in claim 9 wherein said at least one blend mesh is selected from said first set of meshes.

11. The invention as defined in claim 9 wherein said at least one blend mesh is selected from said second set of meshes.

12. The invention as defined in claim 9 wherein said means for creating further comprises means for selecting a plurality of meshes adjacent each said border to form said at least one blend mesh.

13. The invention as defined in claim 9 wherein said first set of meshes contains road link data for each type of road link which varies as a function of a further parameter and wherein said means for adjusting further comprises means for adjusting the traffic data in said at least one blend mesh as a function of said further parameter.

14. The invention as defined in claim 13 wherein said further parameter comprises time of day.

15. The invention as defined in claim 13 wherein said further parameter comprises different types of weather conditions.

16. The invention as defined in claim 9 wherein said means for adjusting further comprises means of adjusting the traffic data in said at least one blend mesh as a function of distance across said at least blend mesh between said first and said second set of meshes.

17. For use with a map database divided into geographic meshes, each mesh containing a plurality of road links of different types, wherein a first set of said meshes contain traffic flow data while a mutually exclusive second set of said meshes contain primarily statically preassigned speed values, a method for geographic interpolation of traffic data comprising the steps of:

identifying one or more borders between said first set and said second set of said meshes,

selecting at least one blend mesh from one of said first and second sets of meshes by selecting at least one mesh adjacent each said border so that said at least one blend mesh is interposed between said first and said second set of meshes,

adjusting the traffic data for each type of road link in the blend meshes to a value between adjacent meshes in said first set of meshes and adjacent meshes in said second set of meshes for each type of road link,

storing said adjusted traffic data for said at least one blend mesh.

18. The invention as defined in claim 17 wherein said at least one blend mesh is selected from said first set of meshes.

19. The invention as defined in claim 17 wherein said at least one blend mesh is selected from said second set of meshes.