Method for detecting a vehicle traffic status and system for detecting said traffic status

• US 6,489,920 B1
• Filed: 01/17/2001
• Issued: 12/03/2002
• Est. Priority Date: 07/17/1998
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Stein, Matthias, Anders, Armin
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US09/744,008
• Time in Patent Office: 685 Days
• Field of Search: 342/25, 342/27, 342/28, 342/52-66, 342/175, 342/176, 342/179, 342/188, 342/189-197, 342/104, 340/934, 340/933, 705/7, 705/8, 701/117, 701/118, 701/119
• US Class Current: 342/179
• CPC Class Codes: G08G 1/04 using optical or ultrasonic detectors

Abstract

From a body located at a distance above the surface of the earth, an image is recorded of a region that is located underneath the body on or above the surface of the earth and that has a diameter of at least one kilometer. The recorded image is fully geocoded and comprises a grid dimension small enough that vehicle densities located in the region can be recognized. The recorded image is evaluated with respect to these vehicle densities and the spatial allocation thereof to the associated roadways. The method is used for acquisition of the state of street traffic over a large area.

Claims

1. A method for acquiring a traffic state of vehicles, comprising the steps of:

from a body located at a distance above a surface of the earth, generating an image of a region located underneath the body at or above the surface of the earth and that has a lateral diameter of at least one kilometer;

recording said image with a resolution that is small enough so that a density of at least one particular vehicle type located in the region is recognized up to a predetermined maximum density; and

evaluating the recorded image with regard to at least one density for at least one type of vehicle.

2. The method according to claim 1 wherein a geosatellite orbiting the earth is used as the body.

3. The method according to claim 1 whereby the image of the region having a diameter on the order of magnitude of at least 10 kilometers is recorded.

4. The method according to claim 1 whereby a geostationary geosatellite is used as the body.

5. The method according to claim 1 wherein an aircraft is used as the body.

6. The method according to claim 5 wherein the image recorded of the region has a diameter on the order of magnitude of one kilometer.

7. The method according to claim 1 wherein the image is recorded using a radar radiation.

8. The method according to claim 1 wherein the image is recorded with the use of interferometry.

9. The method according to claim 1 wherein the image is recorded with use of Doppler effect.

10. The method according to claim 1 wherein a spatial allocation is produced by means of georeferencing between a density recognized in the image of the region of vehicles, and a roadway of the region.

11. The method according to claim 1 wherein after the recording of the image of the region, at least one additional image of the region is recorded, and is likewise evaluated with respect to the at least one density of the at least one particular type of vehicle located in the region, and whereby at least two images recorded in this way are compared with one another.

12. The method according to claim 11 wherein at least one sequence of two images of the region is produced by individual momentary exposures succeeding one another chronologically within one hour.

13. The method according to claim 1, further comprising the step of converting a particular information content of the recorded image into coded data signals.

14. The method according to claim 13, wherein the coded signals are georeferenced coded signals.

15. The method according to claim 14, further comprising the step of processing the data signals to obtain an item of information concerning a traffic state in the region.

16. The method according to claim 15, further comprising the step of supplying the obtained item of information to a use unit.

17. A method of determining a traffic state of vehicles, comprising the steps of:

selecting a resolution for an image-producing beam so that separate vehicles whose traffic state is to be determined cannot be distinguished in an image produced by the image-producing beam when a spacing between the vehicles is less than or equal to the resolution;

radiating the image-producing beam having the selected resolution from a body located at a distance above a surface of a region in which the state of traffic is to be determined, the region having a lateral diameter of at least one kilometer;

recording the image produced by the image-producing beam, wherein first vehicles spaced apart more than the resolution are separately distinguishable in the recorded image and wherein groups of plural second vehicles spaced apart less than or equal to the resolution form continuous lines in the recorded image; and

evaluating a density of vehicles in the recorded image based on occurrences of the continuous lines.

18. The method according to claim 17, further comprising the steps of:

recording another image in the region;

evaluating a density of vehicles in the another recorded image; and

comparing the recorded and the another recorded images to determine changes in the state of traffic.

19. The method according to claim 18, wherein in said recording another image step, the image and the another image are recorded chronologically within one hour.

20. The method according to claim 17, further comprising the step of controlling a traffic guidance system based on the compared images.