Method and apparatus for detecting hot rail car surfaces

• US 20030187605A1
• Filed: 05/29/2002
• Published: 10/02/2003
• Est. Priority Date: 03/29/2002
• Status: Active Grant

• Current Assignee: Progress Rail Services Corporation (Caterpillar Incorporated)
• Original Assignee: GE Global Research (GE Aerospace)
• Inventors: Ringermacher, Harry Israel, Davenport, David Michael, Mathews, Harry Kirk Jr., Houpt, Paul Kenneth, Dixon, Walter Vincent
• Granted Patent: US 6,911,914 B2
• Time in Patent Office: Days
• US Class Current: 702/134
• CPC Class Codes: B61K 9/04 Detectors for indicating the overheating of axle bearings and the like, e.g. associated with the brake system for applying the brakes in case of a fault

Abstract

In one embodiment of the present invention, an apparatus for detecting a hot rail car surface comprises: an infrared sensor for acquiring an infrared signal from a rail car surface of a rail car and transducing the infrared signal into an electrical signal; a rank filter for filtering the electrical signal to produce a filtered array; a first peak detector for detecting a maximum filtered value of the filtered array; and a first comparator for comparing the maximum filtered value to a detection threshold to produce a filtered alarm signal.

Claims

1. An apparatus for detecting a hot rail car surface comprising:

an infrared sensor for acquiring an infrared signal from a rail car surface of a rail car and transducing said infrared signal into an electrical signal;

a rank filter for filtering said electrical signal to produce a filtered array;

a first peak detector for detecting a maximum filtered value of said filtered array; and

a first comparator for comparing said maximum filtered value to a detection threshold to produce a filtered alarm signal.

2. The apparatus of claim 1 wherein said rank filter has a rank of about one-half.

3. The apparatus of claim 1 further comprising:

a wireless transceiver for acquiring rail car surface characteristics from a wireless tag mounted on said rail car; and

a filter parameter calculator for calculating a filter length and rank of said rank filter as a function of said rail car surface characteristics.

4. The apparatus of claim 1 further comprising:

an unfiltered signal buffer for buffering said electrical signal to produce an unfiltered array;

a second peak detector for detecting a maximum unfiltered value of said unfiltered array;

a second comparator for comparing said maximum unfiltered value to said detection threshold to produce an unfiltered alarm signal; and

an alarm comparator for comparing said unfiltered alarm signal to said filtered alarm signal to produce a censored false alarm signal.

5. The apparatus of the previous claim wherein:

said censored false alarm signal comprises a binary signal having a true value when said unfiltered alarm signal differs from said filtered alarm signal and a false value otherwise; and

said apparatus further comprises a counter for counting said false values to produce a censored false alarm count.

6. The apparatus of the previous claim further comprising a failure isolator for diagnosing a failure mode from said censored false alarm count.

7. An apparatus for detecting a hot rail car surface comprising:

an infrared sensor for acquiring an infrared signal from a rail car surface of a rail car and transducing said infrared signal into an electrical signal;

a rank filter for filtering said electrical signal to produce a filtered array;

a first peak detector for detecting a maximum filtered value of said filtered array;

a first comparator for comparing said maximum filtered value to a detection threshold to produce a filtered alarm signal;

a wireless transceiver for acquiring rail car surface characteristics from a wireless tag mounted on said rail car;

a filter parameter calculator for calculating a filter length and rank of said rank filter as a function of said rail car surface characteristics;

an unfiltered signal buffer for buffering said electrical signal to produce an unfiltered array;

a second peak detector for detecting a maximum unfiltered value of said unfiltered array;

a second comparator for comparing said maximum unfiltered value to said detection threshold to produce an unfiltered alarm signal; and

an alarm comparator for comparing said unfiltered alarm signal to said filtered alarm signal to produce a censored false alarm signal.

8. The apparatus of the previous claim wherein:

said censored false alarm signal comprises a binary signal having a true value when said unfiltered alarm signal differs from said filtered alarm signal and a false value otherwise; and

said apparatus further comprises a counter for counting said false values to produce a censored false alarm count.

9. The apparatus of the previous claim further comprising a failure isolator for diagnosing a failure mode from said censored false alarm count.

10. A method for detecting hot rail car surfaces, the method comprising:

acquiring an infrared signal from a rail car surface of a rail car;

transducing said infrared signal into an electrical signal;

filtering said electrical signal using a rank filter to produce a filtered array;

detecting a maximum filtered value of said filtered array; and

comparing said maximum filtered value to a detection threshold to produce a filtered alarm signal.

11. The method of claim 10 wherein said rank filter has a rank of about one-half.

12. The method of claim 10 further comprising:

acquiring rail car surface characteristics from a wireless tag mounted on said rail car; and

calculating a filter length and rank of said rank filter as a function of said rail car surface characteristics.

13. The method of claim 10 further comprising:

buffering said electrical signal to produce an unfiltered array;

detecting a maximum unfiltered value of said unfiltered array;

comparing said maximum unfiltered value to said detection threshold to produce an unfiltered alarm signal; and

comparing said unfiltered alarm signal to said filtered alarm signal to produce a censored false alarm signal.

14. The method of the previous claim wherein:

said censored false alarm signal comprises a binary signal having a true value when said unfiltered alarm signal differs from said filtered alarm signal and a false value otherwise; and

said method further comprises counting said false values to produce a censored false alarm count.

15. The method of the previous claim further comprising diagnosing a failure mode from said censored false alarm count.

16. A method for detecting hot rail car surfaces, the method comprising:

acquiring an infrared signal from a rail car surface of a rail car;

transducing said infrared signal into an electrical signal;

filtering said electrical signal using a rank filter to produce a filtered array;

detecting a maximum filtered value of said filtered array;

comparing said maximum filtered value to a detection threshold to produce a filtered alarm signal;

acquiring rail car surface characteristics from a wireless tag mounted on said rail car;

calculating a filter length and rank of said rank filter as a function of said rail car surface characteristics;

buffering said electrical signal to produce an unfiltered array;

detecting a maximum unfiltered value of said unfiltered array;

comparing said maximum unfiltered value to said detection threshold to produce an unfiltered alarm signal; and

comparing said unfiltered alarm signal to said filtered alarm signal to produce a censored false alarm signal.

17. The method of the previous claim wherein:

said censored false alarm signal comprises a binary signal having a true value when said unfiltered alarm signal differs from said filtered alarm signal and a false value otherwise; and

said method further comprises counting said false values to produce a censored false alarm count.

18. The method of the previous claim further comprising diagnosing a failure mode from said censored false alarm count.