Method And System For Determining The Position Of An Object Moving Along A Course

• US 20070203640A1
• Filed: 03/03/2005
• Published: 08/30/2007
• Est. Priority Date: 03/05/2004
• Status: Active Grant

• Current Assignee: Alstom Belgium SA (Alstom SA)
• Original Assignee: Alstom Belgium SA (Alstom SA)
• Inventors: Rousseau, Michel
• Granted Patent: US 7,769,538 B2
• Time in Patent Office: Days
• US Class Current: 701/207
• CPC Class Codes: B61L 2205/04 Satellite based navigation systems, e.g. global positioning system [GPS]
• CPC Class Codes: B61L 25/021 Measuring and recording of train speed
• CPC Class Codes: B61L 25/025 Absolute localisation, e.g. providing geodetic coordinates
• CPC Class Codes: B61L 25/026 Relative localisation, e.g. using odometer

Abstract

A method is provided for determining the location and/or the positioning of an object, in particular a vehicle such as a train, moving along a known course, including the following steps: determining an absolute position of the object with a first confidence interval, determining a relative position of the object with a second confidence interval, selecting the smaller confidence interval among the first and the second confidence interval, determining said location and/or positioning of the object by means of the position corresponding to said smaller confidence interval.

Claims

1-10. -10. (canceled)

11. A method for determining a position of an object moving along a known course comprising steps of:

determining an absolute position of the object with a first confidence interval;

determining a relative position of the object with a second confidence interval;

determining a smaller confidence interval of the first and second confidence intervals; and

determining the position of the object using the absolute or relative position corresponding to the smaller confidence interval.

12. The method as recited in claim 11 wherein the object is a vehicle.

13. The method as recited in claim 12 wherein the vehicle is a train.

14. The method as recited in claim 11 wherein the step of determining the absolute position includes a railway-safe positioning method involving a digital mapping of possible trajectories and at least one satellite communication receiver.

15. The method as recited in claim 14 wherein the at least one satellite communication receiver is a GNSS receiver.

16. The method as recited in claim 11 wherein the step of determining a relative position includes detecting the presence of a beacon and integrating a speed of the object with reference to a location of the beacon.

17. The method as recited in claim 16 wherein the speed is calculated via a GNSS Doppler signal.

18. The method as recited in claim 11 wherein the first and second confidence intervals determine the position of the object with an error probability in the order of 10⁻

9.

19. The method as recited in claim 18 wherein the error probability is in the order of 10⁻

12.

20. The method as recited in claim 11 wherein the first confidence interval for the absolute position is in the order of 50 m.

27. A location device for determining a position of an object moving along a known course comprising:

an absolute position determining system yielding a first confidence interval and having access to a digital mapping of possible trajectories and at least one satellite communication receiver;

a relative position determining system yielding a second confidence interval and detecting a presence of beacons placed along the course; and

means for selecting a smaller confidence interval among the first and second confidence intervals,

the position of the object determined according to the method as recited in claim 11.

28. The location device as recited in claim 27 wherein the satellite communication receiver is a GNSS receiver.

29. The location device as recited in claim 27 wherein the absolute position device includes means to access the digital mapping of possible trajectories.

30. The location device as recited in claim 27 wherein the relative position determining system includes means to detect the presence of beacons placed along the course.

21. A location device for determining a position of an object moving along a known course comprising:

an absolute position determining system yielding a first confidence interval and having access to a digital mapping of possible trajectories and at least one satellite communication receiver; and

a relative position determining system yielding a second confidence interval and detecting a presence of beacons placed along the course.

22. The location device as recited in claim 21 wherein the object is a vehicle.

23. The location device as recited in claim 22 wherein the object is a train.

24. The location device as recited in claim 21 wherein the satellite communication receiver is a GNSS receiver.

25. The location device as recited in claim 21 wherein the absolute position device includes means to access the digital mapping of possible trajectories.

26. The location device as recited in claim 21 wherein the relative position determining system includes means to detect the presence of beacons placed along the course.