Method and system for obtaining lane data

• US 6,850,841 B1
• Filed: 05/15/2003
• Issued: 02/01/2005
• Est. Priority Date: 05/15/2003
• Status: Expired due to Term

• Current Assignee: HERE Global B.V. (Nokia Corporation)
• Original Assignee: Navtech North American LLC
• Inventors: Casino, Roy
• Primary Examiner(s): Chin, Gary
• Application Number:
  US10/439,000
• Time in Patent Office: 628 Days
• Field of Search: 701/200, 701/208, 701/213, 340/995.1, 340/995.14, 340/995.18, 340/995.28
• US Class Current: 701/208
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network

Abstract

A method for collecting data for a geographic database is disclosed. A plurality of vehicles moving on roads in a geographic region collects data indicating position of the vehicle. For a location on a selected road, the method obtains a cross sectional distribution of the position data. The method identifies a number of steps in the distribution indicating a number of lanes on the selected road and updates the geographic database with data indicating the number of lanes.

Claims

1. A method of obtaining data for a geographic database using a plurality of vehicles moving on roads in a geographic region comprising the steps of:

for each vehicle, collecting data indicating positions of the vehicle as the vehicle travels the roads in the geographic region,

for a location on a selected road, obtaining a cross sectional distribution graph of the position data;

identifying a number of incremental steps in said distribution graph to indicate a number of lanes on the selected road; and

updating said geographic database with said data indicating said number of lanes.

2. The method of claim 1 further comprising determining a lane width as a distance between adjacent incremental steps of said distribution graph.

3. The moth of claim 1 further comprising if said number of incremental steps is an odd number, identifying a location of a centerline as a position corresponding to a center of said distribution graph.

4. The method of claim 1 further comprising if said number of incremental steps is an even number, identifying a location of a lane boundary line as a position corresponding to a center of said distribution graph.

5. The method of claim 1 further comprising:

determine a lane width as a distance between adjacent incremental steps of said distribution graph;

if said number of incremental steps is an odd number, identifying a location of a lane boundary line as a position approximately a distance of one half of said lane width from a position corresponding to a center of said distribution graph; and

if said number of incremental steps is an even number, identifying a location of a lane center line as a position approximately a distance of one half of said lane width from the position corresponding to the center of said distribution graph.

6. The method of claim 1 wherein the position data is collected with a vehicle navigation system.

7. The method of claim 1 further comprising filtering the position data.

8. The method of claim 1 wherein the position data is determined with a positioning system having accuracy worse than a width of a lane of said roads.

9. The method of claim 8 wherein said positioning system is a GPS unit having accuracy of approximately 15 meters.

10. The method of claim 1 further comprising inferring a location of a median on the selected road segment.

11. A method for collecting data for a geographic database that represents roads in a geographic region, the method comprising:

with a plurality of vehicles that travel along the roads, collecting position data having accuracy worse than a width of a lane of the road;

obtaining a cross sectional distribution graph of the position data for a selected road;

analyzing said cross sectional distribution graph, wherein said analyzing step comprises identifying a number of incremental steps in said distribution graph indicating a number of lanes of the selected road; and

storing data in said geographic database that represent lane attribute information.

14. The method of claim 11 wherein said analyzing step comprises:

if said number of incremental steps is an odd number, identifying a location of a centerline corresponding to a center of said distribution graph; and

if said number of incremental steps is an even number, identifying a location of a lane boundary line corresponding to a center of said distribution graph.

15. The method of claim 11 wherein said analyzing step comprises:

determining a lane width as a distance between adjacent incremental steps of said distribution graph;

if said number of incremental steps is an odd number, identifying a location of a lane boundary line as a position approximately a distance of one half of said lane width from a center of said distribution graph; and

if said number of incremental steps is an even number, identifying a location of a lane centerline as a position approximately the distance of one half of said lane width from the center of said distribution graph.

17. The method of claim 11 wherein said position data is determined with a GPS unit having accuracy of approximately 15 meters.

12. A method for collecting data for a geographic database that represents roads in a geographic region, the method comprising:

with a plurality of vehicle that travel along the roads, collecting position data having accuracy worse than a width of a lane of the road;

obtaining a cross sectional distribution graph of the position data for a selected road;

analyzing said cross sectional distribution graph, wherein said analyzing step comprising determining a distance between end edges of said distribution graph and comparing said distance to predetermined values indicating a number of lanes of said selected road; and

storing data in said geographic database that represent lane attribute information.

13. A method for collecting data for a geographic database that represents roads in a geographic region, the method comprising:

with a plurality of vehicles that travel along the roads, collecting position data having accuracy worse than a width of a lane of the road;

obtaining a cross sectional distribution graph of the position data for a selected road;

analyzing said cross sectional distribution graph, wherein said analyzing step comprises determining a lane width as a distance between adjacent incremental steps of said distribution graph; and

storing data in said geographic database that represent lane attribute information.

16. A method for collecting data for a geographic database that represents roads in a geographic region, the method comprising:

with a plurality of vehicles that travel along the roads, collecting position data having accuracy worse than a width of a lane of the road;

obtaining a cross sectional distribution graph of the position data for a selected road;

analyzing said cross sectional distribution graph, wherein said analyzing step comprises;

for one side of the distribution graph, identifying distance values between each adjacent incremental step;

if one of said distance values is larger than another of said distance values by a predetermined amount, inferring a location of a median; and

storing data in said geographic database that represent lane attribute information.

18. A system for collecting data for a geographic database that represents roads in a geographic region comprising:

a data collection unit located in a vehicle that travel along the road in the geographic region;

a GPS unit associated with the vehicle, said GPS unit providing position data having an accuracy worse than a width of a lane of the roads to said data collection unit;

a data processing unit receiving position data from a plurality of the vehicles, obtaining a cross sectional distribution graph of the position data and identifying a number of incremental steps in said distribution graph to indicate a number of lanes.

19. The system of claim 18 wherein said data processing unit is located in a data collection facility.

20. The system of claim 18 wherein said data processing unit determines a distance between end edges of said distribution graph and compares said distance to predetermined values indicating a number of lanes of a selected road.

21. The system of claim 18 wherein said data processing unit determines a lane width as a distance between adjacent incremental steps of said distribution.

22. The system of claim 18 wherein the data processing unit identifies said number of incremental steps in said distribution graph;

if said number of incremental steps is an odd number, the data processing unit identifies a location of a centerline corresponding to a center of said distribution graph; and

if said number of incremental steps is an even number, the data processing unit identifies a location of a lane boundary line corresponding to a center of said distributions graph.