Method and system for automatic generation of shape and curvature data for a geographic database

• US 6,674,434 B1
• Filed: 10/25/1999
• Issued: 01/06/2004
• Est. Priority Date: 10/25/1999
• Status: Expired due to Term

• Current Assignee: HERE Global B.V. (Nokia Corporation)
• Original Assignee: Navigation Technologies Corp. (Nokia Corporation)
• Inventors: Chojnacki, Robert, Feigen, Jerry, Boylan, A. Merri
• Primary Examiner(s): Zimmerman, Mark
• Assistant Examiner(s): MANCUSO, HUEDUNG XUAN CAO
• Application Number:
  US09/426,036
• Time in Patent Office: 1,534 Days
• Field of Search: 345/428, 345/751, 345/442, 701/200, 701/201, 701/212, 701/208, 701/209, 701/210, 701/213
• US Class Current: 345/428
• CPC Class Codes: G01C 21/3819 Road shape data, e.g. outline of a route
• CPC Class Codes: G01C 21/3837 Data obtained from a single source
• CPC Class Codes: G01C 21/3844 Data obtained from position sensors only, e.g. from inertial navigation
• CPC Class Codes: G06F 30/15 Vehicle, aircraft or watercraft design
• CPC Class Codes: G06T 17/05 Geographic models

Abstract

A process and system for collecting data about roads located in a geographic area and using the collected data to develop representations of the locations and geometry of the roads for a geographic database. A vehicle in which data acquisition equipment is installed is driven on the roads. Using the data acquisition equipment, data are collected representing positions of the vehicle as it is being driven along the roads and data indicating the path of the vehicle as it is being driven along the roads. The data acquired while traveling may be smoothed and fused. The data acquired while traveling are processed by a program that automatically selects which of the data are necessary to provide a specified level of accuracy in a geographic database that includes data that represent the roads including data that represent positions and geometry of the roads. The data selected by the program are stored in the geographic database.

Claims

1. A method of storing data in a geographic database to represent road shape comprising the steps of:

obtaining source data that represent a plurality of points along roads;

determining which of said plurality of points are necessary to represent the roads with a desired level of accuracy; and

storing in said geographic database data to represent those points determined to be necessary,

wherein said step of determining is based upon an evaluation of said plurality of points such that a straight line connecting any two adjacent necessary points is not farther from any of said plurality of points located between said two adjacent necessary points than a distance associated with said level of accuracy away.

2. A method of storing data in a geographic database to represent road shape comprising the steps of:

obtaining source data that represent a plurality of points along roads;

determining which of said plurality of points are necessary to represent the roads with a desired level of accuracy; and

storing in said geographic database data to represent those points determined to be necessary,

wherein said step of determining is based upon an evaluation of said plurality of points such that each point determined not to be necessary is located less than a distance associated with said level of accuracy away from a straight line that connects the closest necessary points on either side of said point determined not be necessary.

3. A method of making geographic database products comprising the steps of:

obtaining source data that represent a plurality of points along roads;

determining which of said source data are necessary to represent said roads with a level of accuracy corresponding to a highest level of accuracy required for a derived database product;

storing in a master geographic database those source data determined to be necessary to represent said roads with at least said highest level of accuracy;

forming the first derived database product with the source data contained in said master geographic database;

determining which of said source data are necessary to represent said roads with a level of accuracy that is lower than the highest level; and

forming a second derived database product from the source data determined to be necessary to represent said roads with said level of accuracy that is lower than the highest level.

4. The method of claim 3 wherein said highest level of accuracy is specified to be a value less than approximately 1 meter.

5. The method of claim 3 wherein said highest level of accuracy is specified to be a value between approximately 3 and 5 meters.

6. The method of claim 3 wherein said highest level of accuracy is specified to be a value between approximately 1 and 3 meters.

7. The method of claim 3 wherein said source data comprise raw sensor data.

8. The method of claim 3 wherein said source data comprise raw sensor data formed as a result of a fusing step in which each raw sensor reading is modified to take into account sensor readings from a plurality of different types of sensors.

9. The method of claim 3 wherein said source data are acquired while driving a vehicle along said roads.

10. The method of claim 3 wherein said source data are acquired using an inertial sensor system and a GPS system.

11. The method of claim 3 further comprising the step of:

modifying those data that represent a plurality of points along roads to align with centerlines of the roads represented thereby.

12. The method of claim 11 wherein said step of modifying is performed after said step of determining.

13. The method of claim 3 wherein said second derived database product is formed from the source data contained in said master geographic database.

14. A method of making geographic database products comprising the steps of:

obtaining source data that represent a plurality of points along roads;

determining which of said source data are necessary to represent said roads with a specified planar level of accuracy and a specified vertical level of accuracy; and

storing in a master geographic database those source data determined to be necessary to represent said roads with said specified planar level of accuracy and said specified vertical level of accuracy.

15. The method of claim 14 wherein said source data are acquired using a data collection system installed in a vehicle that is driven along said roads.

16. A geographic database stored on a computer readable medium formed according to the process of claim 3 or 14.

17. The method of claim 14 wherein said specified planar level of accuracy is different from said specified vertical level of accuracy.