Detecting Train Separation

• US 20150000415A1
• Filed: 02/01/2013
• Published: 01/01/2015
• Est. Priority Date: 02/01/2012
• Status: Abandoned Application

• Current Assignee: Optasense Holdings Limited (Luna Innovations, Inc.)
• Original Assignee: Optasense Holdings Limited (Luna Innovations, Inc.)
• Inventors: Kelley, John
• Application Number:
  US14/375,906
• Publication Number:
  US 20150000415A1
• Time in Patent Office: Days
• US Class Current: 73/649
• CPC Class Codes: B61L 1/14 Devices for indicating the passing of the end of the vehicle or train
• CPC Class Codes: B61L 1/166 Optical
• CPC Class Codes: B61L 15/00 Indicators provided on the vehicle or train for signalling purposes
• CPC Class Codes: B61L 15/0054 Train integrity supervision, e.g. end-of-train [EOT] devices
• CPC Class Codes: B61L 5/12 Visible signals
• CPC Class Codes: B61L 5/206 Signalling means for special purposes
• CPC Class Codes: G01H 9/004 using fibre optic sensors light guides per se G02B6/00, acousto-optical devices specially adapted for gating or modulating in optical wave guides G02F1/125
• CPC Class Codes: G01N 2291/011 Velocity or travel time
• CPC Class Codes: G01N 2291/023 Solids
• CPC Class Codes: G01N 2291/025 Change of phase or condition
• CPC Class Codes: G01N 29/07 by measuring propagation velocity or propagation time of acoustic waves
• CPC Class Codes: G01N 29/4454 Signal recognition, e.g. specific values or portions, signal events, signatures

Abstract

This application describes method and apparatus for detecting train separation, where one or more railway cars/carriages (401) accidentally decouple from the rest of the train. The method involves performing distributed acoustic sensing on at least one optical fibre (104a, 104b) to provide a plurality of longitudinal acoustic sensor portions along the railway (201). The acoustic response is analysed to detect a signature indicative of a train separation. This may involve detecting acoustic events (302, 303) associated with different parts of the train and detecting when the separation between the two events exceeds a threshold amount. The method may identify the front of the train and the rear of the train and detect when the distance between the front and rear changes by more than a threshold amount and/or sounds associated with wheelsets passing track features (402) may be used to determine the intervals (T₃, T₄) between wheelsets of adjacent cars and determine when the interval exceeds a threshold amount. The threshold may be based on the interval (T₂) between wheelsets of the same car passing the track feature.

Claims

1. A method detecting separation of a train comprising:

performing distributed acoustic sensing on at least one optical fibre deployed along the length of a railway so as to provide a plurality of longitudinal acoustic sensor portions along the railway;

analysing the acoustic response from said acoustic sensor portions to detect a signature indicative of a train having separated.

2. A method as claimed in claim 1 wherein said detecting said signature comprises detecting a first acoustic event associated with a first part of a train and a second acoustic event associated with a second different part of the train and detecting that the separation between the first acoustic event and second acoustic event is beyond a threshold.

3. A method as claimed in claim 1 comprising analysing the acoustic response from the acoustic sensor portions to locate an acoustic signal indicative of the front of the train and an acoustic signal associated with the rear of the train and determining the distance between the acoustic signals indicative of the front and the rear of the train.

4. A method as claimed in claim 3 comprising repeatedly determining the distance between the acoustic signals indicative of the front and the rear of the train and detecting if said distance increases beyond a threshold amount.

5. A method as claimed in claim 4 wherein said threshold is based on the previously determined distance between the front and rear of the train.

6. A method as claimed in claim 3 wherein detecting the acoustic signals associated with the front and rear of the train respectively comprises identifying the beginning and end of a continuous acoustic disturbance indicative of the train.

7. A method as claimed in claim 3 wherein detecting the acoustic signals associated with the front and rear of the train respectively comprises identifying the first sensing portion and last sensing portion to detect an acoustic signature resulting from the wheelsets passing track features.

8. A method as claimed in claim 1 comprising identifying acoustic features associated with separate cars of the train.

9. A method as claimed in claim 8 comprising identifying acoustic signals associated with a wheelset and detecting the interval between acoustic signals corresponding to different wheelsets.

10. A method as claimed in claim 9 wherein identifying acoustic signals associated with a wheelset comprises identifying a relatively intense broadband noise component in the acoustic response from said acoustic sensor portions.

11. A method as claimed in claim 9 wherein identifying acoustic signals associated with a wheelset comprises identifying acoustic signals associated with a wheelset passing a track feature.

12. A method as claimed in claim 9 comprising identifying the interval between acoustic features generated by the wheelsets on the same car and the interval between features generated by wheelsets on different cars.

13. A method as claimed in claim 12 wherein the method comprises determining whether the interval between features generated by wheelsets on different cars exceeds a threshold based on the interval between wheelsets on the same car.

14. A method as claimed in claim 1 wherein the optical fibre is deployed alongside the track.

15. A method as claimed in claim 1 wherein at least part of the optical fibre is buried along the path of the track.

16. A method as claimed in claim 1 wherein at least part of the optical fibre is attached to the track.

17. A method as claimed in claim 1 wherein at least part of the optical fibre is deployed adjacent to a plurality of adjacent tracks.

18. A method as claimed in claim 17 further comprising identifying which of the plurality of adjacent tracks a train is travelling on.

19. A method as claimed in claim 1 comprising, in the event a train having separated is detected, identifying the location of the train split.

20. A method as claimed in claim 1 comprising, in the event a train having separated is detected, generating an alarm.

23. A computer program stored on non-transitory storage medium, the computer program comprising computer readable code for instructing a suitable computer system to perform the method of claim 1.

21. A method of detecting separation of a train comprising:

receiving measurement signals corresponding to detected acoustic signals from a plurality of locations along the length of a railway; and

analysing the measurement signals to detect a signature indicative of a train having separated.

22. A method as claimed in claim 21 wherein said measurement signals are acquired by performing distributed acoustic sensing on an optical fibre deployed along the length of the railway.

24. (canceled)

25. A system for detecting for train split comprising:

a controller configured to;

receive measurement signals from at least one distributed acoustic sensor unit configured to perform distributed acoustic sensing on at least one optical fibre deployed along the length of a railway so as to provide a plurality of longitudinal acoustic sensor portions along the railway; and

analyse the acoustic response from said acoustic sensor portions to detect a signature indicative of a train separation.

26. A system as claimed in claim 25 further comprising at least one distributed acoustic sensor unit.

27. (canceled)