U.S. patent application number 11/721657 was filed with the patent office on 2008-05-08 for broken rail detection system.
Invention is credited to Kenneth A. Karg.
Application Number | 20080105791 11/721657 |
Document ID | / |
Family ID | 36588431 |
Filed Date | 2008-05-08 |
United States Patent
Application |
20080105791 |
Kind Code |
A1 |
Karg; Kenneth A. |
May 8, 2008 |
Broken Rail Detection System
Abstract
A system is for performing broken rail detection on a railway
track. The system includes at least one locomotive and a monitoring
entity. Each locomotive includes a receiver for receiving a track
signal that is circulating in the railway track and a processing
unit that is in communication with the receiver. The processing
unit is operative for detecting a characteristic of the track
signal and generating a signal indicative of a potential broken
rail in response to a change in the characteristic of the track
signal. The locomotive further includes a wireless transmitter for
transmitting the signal indicative of a potential broken rail over
a wireless communication link. The monitoring entity includes a
receiver for receiving the signal indicative of a potential broken
rail and a processing unit for detecting a broken rail at least in
part on the basis of the signal indicative of a potential broken
rail from the locomotive.
Inventors: |
Karg; Kenneth A.; (Belle
Vernon, PA) |
Correspondence
Address: |
KENYON & KENYON LLP
ONE BROADWAY
NEW YORK
NY
10004
US
|
Family ID: |
36588431 |
Appl. No.: |
11/721657 |
Filed: |
December 12, 2005 |
PCT Filed: |
December 12, 2005 |
PCT NO: |
PCT/US05/44884 |
371 Date: |
June 13, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60635003 |
Dec 13, 2004 |
|
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|
Current U.S.
Class: |
246/120 |
Current CPC
Class: |
B61L 23/044 20130101;
B61K 9/10 20130101; B61L 3/121 20130101 |
Class at
Publication: |
246/120 |
International
Class: |
B61K 9/10 20060101
B61K009/10 |
Claims
1-33. (canceled)
34. A locomotive for travelling on a railway track, comprising: a
receiver configured to receive a track signal circulating in the
railway track; a processor unit in communication with the receiver,
the processor unit configured to: (a) detect a characteristic of
the track signal; and (b) generate a signal indicative of a
potential broken rail in response to a change in the characteristic
of the track signal circulating in the railway track.
35. The locomotive according to claim 34, wherein the
characteristic includes presence of the track signal circulating in
the railway track.
36. The locomotive according to claim 34, wherein the
characteristic includes a strength of the track signal circulating
in the railway track.
37. The locomotive according to claim 34, wherein the
characteristic includes a signature of the track signal circulating
in the railway track.
38. The locomotive according to claim 34, further comprising a
transmitter configured to transmit the track signal into the
railway track.
39. The locomotive according to claim 38, wherein the track signal
includes a low frequency signal.
40. The locomotive according to claim 39, wherein the track signal
includes an audio signal.
41. The locomotive according to claim 38, wherein the processor
unit includes a signal generation unit in communication with the
transmitter, the signal generation unit configured to select a
frequency of the track signal.
42. The locomotive according to claim 41, wherein the receiver is
configured to select a frequency of track signals being
detected.
43. The locomotive according to claim 34, further comprising a
wireless transmitter configured to transmit the signal indicative
of a potential broken rail to a monitoring entity.
44. The locomotive according to claim 43, wherein the wireless
transmitter is configured to transmit, to the monitoring entity,
information indicative of a location of the locomotive.
45. The locomotive according to claim 43, further comprising a
wireless receiver configured to receive signals from the monitoring
entity.
46. The locomotive according to claim 45, wherein the wireless
receiver is configured to receive railway track information from
the monitoring entity.
47. The locomotive according to claim 46, wherein the railway track
information includes information indicative of at least one of: (a)
a location of a shunt on the railway track; (b) a location of
another locomotive on the railway track; and (c) a position of a
switch on the railway track.
48. The locomotive according to claim 43, wherein the signal
indicative of a potential broken rail includes information
associated with a portion of track surveyed by the locomotive.
49. The locomotive according to claim 45, wherein the wireless
transmitter and the wireless receiver are configured to communicate
with the monitoring entity over an RF communication link.
50. A system for performing broken rail detection on a railway
track, comprising: at least one locomotive including: a receiver
configured to receive a track signal circulating in the railway
track; a processor unit in communication with the receiver and
configured to: (a) detect a characteristic of the track signal; and
(b) generate a signal indicative of a potential broken rail in
response to a change in the characteristic of the track signal
circulating in the railway track; and a wireless transmitter
configured to transmit the signal indicative of a potential broken
rail over a wireless communication link; and a monitoring entity
including: a receiver configured to receive the signal indicative
of a potential broken rail from the locomotive; and a processor
unit configured to detect a broken rail at least in part in
accordance with the signal indicative of a potential broken rail
from the locomotive.
51. The system according to claim 50, wherein the characteristic
includes presence of the track signal circulating in the railway
track.
52. The system according to claim 50, wherein the characteristic
includes a strength of the track signal circulating in the railway
track.
53. The system according to claim 50, wherein the characteristic
includes a signature of the track signal circulating in the railway
track.
54. The system according to claim 50, wherein the locomotive
includes a transmitter configured to transmit the track signal into
the railway track.
55. The system according to claim 50, wherein the wireless
transmitter is further configured to transmit a signal indicative
of a location of the locomotive to the monitoring entity.
56. The system according to claim 50, wherein the locomotive
includes a wireless receiver configured to receive signals from the
monitoring entity.
57. The system according to claim 56, wherein the wireless receiver
is configured to receive railway track information from the
monitoring entity.
58. The system according to claim 57, wherein the railway track
information includes information indicative of at least one of: (a)
a location of a shunt on the railway track; (b) a location of
another locomotive on the railway track; and (c) a position of a
switch on the railway track.
59. The system according to claim 50, wherein the signal indicative
of a potential broken rail includes information associated with a
portion of track surveyed by the locomotive.
60. The system according to claim 50, wherein the monitoring entity
is configured to initiate an action upon detection of a broken
rail.
61. The system according to claim 60, wherein the action includes
sending a repair team to repair the broken rail.
62. A monitoring entity for performing broken rail detection,
comprising: a wireless receiver configured to receive a signal,
indicative of a potential broken rail, from at least one
locomotive; a processor unit configured to detect a broken rail at
least in part in accordance with the signal from the
locomotive.
63. The monitoring entity according to claim 62, wherein the signal
indicative of a potential broken rail includes information
indicative of a portion of track surveyed by the locomotive.
64. The monitoring entity according to claim 62, further comprising
a wireless transmitter configured to transmit railway track
information to the locomotive.
65. The monitoring entity according to claim 64, wherein the
railway track information includes information indicative of at
least one of: (a) a location of a shunt on the railway track; (b) a
location of a locomotive on the railway track; and (c) a position
of a switch on the railway track.
66. A system for performing broken rail detection, comprising: a
receiver mountable onboard a locomotive that travels on a railway
track, the receiver configured to receive a track signal
circulating in the railway track; and a processor device configured
to communicate with the receiver, the processor device configured
to: (a) detect a characteristic of the track signal; and (b)
generate a signal indicative of a potential broken rail in response
to a change in the characteristic of the track signal circulating
in the railway track.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S.
Provisional Patent Application Ser. No. 60/635,003, filed on Dec.
13, 2004, which is expressly incorporated herein in its entirety by
reference thereto.
FIELD OF THE INVENTION
[0002] The present invention relates to the field broken rail
detection systems, and more particularly to detection systems that
use voltage and/or current signals circulating in the railway track
for detecting broken rails.
BACKGROUND INFORMATION
[0003] In order to ensure the safety of railway transportation, it
is not only important to keep the locomotives in good working
condition, it is also important to keep the railway tracks
themselves in good working condition. Due to excessive use, and
environmental conditions such as extreme temperatures, railway
tracks can deteriorate and eventually break. It is therefore
important to monitor the condition of the railway tracks in order
to ensure that they do not include breaks that could cause them to
be unsafe.
[0004] Certain systems for detecting broken rails are conventional.
As shown in FIG. 1, such systems generally include wayside-based
equipment 10 that is positioned in proximity to the railway tracks
12. The wayside-based equipment 10 is in communication with a
transmitter 14 and a receiver 16. The railway track 12 that is
being monitored is divided into sections by placing shunts 18
across the rails. By so doing, the railway track 12 and the shunts
18 create a closed conductive loop. The transmitter 14 then
introduces either a current or a voltage signal into the closed
loop, such that the signal is able to circulate through the railway
track 12. Meanwhile, the receiver 16 monitors this signal
circulating through the closed loop of the railway track 12. When a
break occurs in the railway track 12, the break will interrupt the
path of the signal, thus preventing the signal from reaching the
receiver 16. When the wayside equipment 10 detects the absence of
the signal at the receiver 16, the wayside-based equipment 10
determines that there is a break in the railway tracks 12.
[0005] Unfortunately, such broken rail detection systems are
plagued with numerous deficiencies. A first such deficiency is that
a significant amount of wire is required in order to connect the
transmitters 14 and the receivers 16 to the wayside equipment 10.
This is not only costly, but is also difficult to maintain.
[0006] A further deficiency with existing systems is that when
trains are running on the track, the broken rail detection system
cannot always be used. More specifically, when a train is
travelling on the railway track between the transmitter 14 and the
receiver 16, the train's axles act as shunts. As such, if a train
is on the track, it will short out the section of track between
itself and the shunt. Referring to FIG. 1, and assuming that a
train's axles are positioned just in front of the break in the
rails 12, the train's axles will complete the closed loop, such
that the receiver 16 will continue to receive the signal that is
circulating in the rails, regardless of the fact that there is a
break in the rails just beyond the train's axle. Therefore,
depending on the placement of the transceiver 14 and the receiver
16, the portion of the rails positioned beyond the portion of the
track that is shunted by the train cannot be monitored. As such,
the wayside equipment will not be able to accurately perform broken
rail detection on the rails when there are trains travelling
thereon. The more trains that are running on the track, the less
the system can accurately perform broken rail detection, since the
trains cause shunting of so much of the track.
[0007] In light of the above, it can be seen that there is a need
in the industry for an improved broken rail detection system that
alleviates, at least in part, the deficiencies of the prior art,
and improves on the overall efficiency of the systems.
SUMMARY
[0008] In accordance with a first broad aspect, example embodiments
of the present invention provide a locomotive for travelling on a
railway track. The locomotive includes a receiver for receiving a
track signal that is circulating in the railway track and a
processing unit that is in communication with the receiver. The
processing unit is operative for detecting a characteristic of the
track signal and for generating a signal indicative of a potential
broken rail in response to the characteristic of the track signal
circulating in the railway track.
[0009] The locomotive may further include a transmitter for
transmitting the track signal into the railway track. It should be
appreciated that the track signal can also be introduced into the
railway track by a different locomotive, or by track-side
equipment.
[0010] In accordance with an example embodiment of the present
invention, a system is provided for performing broken rail
detection on a railway track. The system includes at least one
locomotive and a monitoring entity. The locomotive includes a
receiver for receiving a track signal that is circulating in the
railway track and a processing unit that is in communication with
the receiver. The processing unit is operative for detecting the
presence of the track signal and generating a signal indicative of
a potential broken rail in response to the absence of the track
signal circulating in the railway track. The locomotive further
includes a wireless transmitter for transmitting the signal
indicative of a potential broken rail over a wireless communication
link. The monitoring entity includes a receiver for receiving the
signal indicative of a potential broken rail and a processing unit
for detecting a broken rail at least in part on the basis of the
signal indicative of a potential broken rail from the
locomotive.
[0011] In accordance with an example embodiment of the present
invention, a monitoring entity is provided for performing broken
rail detection. The monitoring entity includes a wireless receiver
and a processing unit. The wireless receiver is operative for
receiving a signal from at least one locomotive; the signal being
indicative of a potential broken rail. The processing unit is
operative for detecting a broken rail at least in part on the basis
of the signal from the at least one locomotive.
[0012] In accordance with an example embodiment of the present
invention, a system is provided for performing broken rail
detection. The system includes a receiving device for mounting
onboard a locomotive that is travelling on a railway track. The
receiving device is operative for receiving a track signal that is
circulating in the railway track. The system further includes a
processing device in communication with the receiving device. The
processing device is operative for detecting the presence of the
track signal and generating a signal indicative of a potential
broken rail in response to the absence of the track signal
circulating in the railway track.
[0013] These and other aspects and features of example embodiments
of the present invention are described in further detail in the
following description with reference to the appended Figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows a schematic view of a conventional broken rail
detection system.
[0015] FIG. 2 shows a top schematic view of a locomotive-based
broken rail detection system in accordance with a non-limiting
example embodiment of the present invention.
[0016] FIG. 3 shows a schematic diagram of a locomotive in
accordance with a non-limiting example embodiment of the present
invention, travelling over a portion of railway track.
[0017] FIG. 4 shows a non-limiting schematic diagram of portions of
a railway track surveyed by the locomotive-based broken rail
detection system of FIG. 2.
[0018] FIG. 5 shows a block diagram of a locomotive in accordance
with a non-limiting example embodiment of the present
invention.
[0019] FIG. 6 shows a schematic diagram of a non-limiting example
embodiment of the present invention.
[0020] FIG. 7 shows a non-limiting example of a flow diagram
performed by a locomotive for generating a signal indicative of a
potential broken rail in accordance with a non-limiting example
embodiment of the present invention.
DETAILED DESCRIPTION
[0021] Shown in FIG. 2 is a broken rail detection system 20 in
accordance with a non-limiting example embodiment of the present
invention. The broken rail detection system 20 includes a
monitoring entity 22 that is in communication with one or more
locomotives 24. For the purposes of the following description,
three locomotives 24a, 24b and 24c are included in the schematic
diagram of FIG. 2. It should, however, be understood that any
number of locomotives 24 can be included as part of the broken rail
detection system 20, without departing from the spirit of the
present invention.
[0022] The monitoring entity 22 is responsible for monitoring the
condition of the railway track 24 in a predefined area or region in
order to determine, among other things, whether the rails in that
region include a break. The predefined area or region may be based
on a certain length of railway track (i.e., 100 miles of track, for
example) or based on a certain geographical area.
[0023] The monitoring entity 22 can be a track-side device, such as
wayside equipment, or can be a remotely located device, such as a
computing unit that is located at a control station, for example.
In use, monitoring entity 22 is operative for detecting a broken
rail in the railway track 26 at least in part on the basis of
signals received from the locomotives 24 travelling on the railway
track 26. As the locomotives 24a, 24b and 24c travel along the
railway track 26, they are operative for surveying a portion of the
railway track 26 in order to detect a potential break in the rails.
The surveying is performed by monitoring a track signal that is
circulating in the railway track 26. As will be described in more
detail below, the track signal can be introduced into the railway
track 26 by the locomotive that is monitoring the signal, by a
different locomotive or by track-side equipment.
[0024] Upon detection of a potentially broken rail in the portion
of railway track being surveyed, the locomotive transmits a signal
indicative of a potential broken rail to the monitoring entity 22.
As such, the monitoring entity 22 includes a receiver 21 for
receiving the signals from the locomotives 24a, 24b and 24c, and a
processing unit 23 for determining, among other things, if there is
a break in one of the rails. As will be described in more detail
below, the monitoring entity 22 can perform the broken rail
detection solely on the basis of the signals received from the
locomotives 24, or in combination with conventional techniques (as
described above) which involve introducing a signal into the rails
via a track-side transmitter 25.
[0025] In order to facilitate the ability of locomotives 24a, 24b
and 24c to survey portions of the railway track 26, the railway
track 26 is divided into sections via shunts 28. The railway track
26 shown in FIG. 2 includes five shunts, which have been labelled
28a, 28b, 28c, 28d and 28e for clarity.
[0026] In accordance with a non-limiting example embodiment, at
least some of the locomotives 24a, 24b and 24c are operative for
introducing a signal into the track 26. Shown in FIG. 3 is a
non-limiting example embodiment of a locomotive 24 in accordance
with the present invention. As shown, the locomotive 24 includes a
transmitter 30 for issuing a signal into a rail of the railway
track 26, and a receiver 32 for receiving the signal introduced
into the railway track 26. The transmitter 30 and the receiver 32
are positioned on the locomotive 24 such that they are set
correctly with respect to the rails.
[0027] The signal that is transmitted into the rails can either be
a current signal or a voltage signal. In a non-limiting example
embodiment, the signal can be, but is not limited to, a low
frequency audio signal having a frequency in the range of 4,000 Hz
to 10,000 Hz. Such signals are inductively transmitted into the
rails.
[0028] Once the signal has been introduced into one of the rails by
the transmitter 30, the signal travels through the rail to the
nearest shunt 28 and then travels back towards the locomotive 24
through the other rail. The shunt 28 can be a conductive rod that
is placed across the rails of the track 26, or alternatively, the
shunt 28 can be an axle of another locomotive travelling on the
track 26. Once the signal has traveled through the shunt 28, it
travels back towards the locomotive 24 that issued the signal. That
locomotive's axle 34 then acts as a second shunt, such that a
closed loop is created between the locomotive 24 and the shunt 28.
The signal introduced into the track 26 is then able to circulate
through this closed loop continuously. In this manner, the receiver
32 is able to receive the signal as it circulates through the
closed loop. As long as the rails are intact, the signal introduced
into the rails is also intact, and the receiver 32 receives the
signal such that it can detect a characteristic of the signal. The
characteristic of the signal can be the presence of the signal, the
strength of the signal or a signature of signal, that can be
detected by digital signal processing techniques, for example. On
the basis of one or more of these characteristics, the locomotive
24 can surveys the railway track 26 for possible breaks.
[0029] In the case where the receiver 32 no longer receives the
signal that is circulating through the railway track 26, it
generally means that there is a break in one or both of the rails,
thus causing a short in the closed circuit. Alternatively, in the
case where the strength of the signal has deteriorated, or the
signature of the signal is incorrect, it could also mean that there
is a break, or a deterioration of the rails in the portion of the
railway track 26 being surveyed. As such, when the receiver 32
fails to receive the track signal, or detects a deterioration in
signal strength, or an incorrect signal signature, the locomotive
24 determines that there is a potential break or deterioration in
one or both of the rails that it is surveying.
[0030] Although FIG. 3 shows only the front end of the locomotive
24, it should be understood that the locomotive 24 may have a
similar transmitter 30 and receiver 32 positioned at the rear end
of the locomotive 24. In such a non-limiting example embodiment,
the locomotive 24 is able to survey both the portion of railway
track 26 in front of it and the portion of railway track 26 behind
it.
[0031] As mentioned above, although the closed loop shown in FIG. 3
is between the front axle 34 of the locomotive 24 and a shunt 28 in
the form of a conductive rod, the loop could also be formed between
two locomotives 24. For example, in the case where there are no
shunts positioned between two locomotives 24 (such as in the case
of locomotives 24b and 24c shown in FIG. 2) then the closed loop is
formed between the rear axle of the front locomotive and the front
axle of the rear locomotive.
[0032] Shown in FIG. 4 is a representation of the portions of the
railway track 26 surveyed by the locomotives 24a, 24b and 24c of
FIG. 2. In this non-limiting example, the locomotive 24a is
operative to introduce a signal into the railway track 26 both
ahead of it and behind it. As such, the locomotive 24a is surveying
the portion of railway track between its rear axle and the shunt
28a, as well as the portion of the railway track 26 between its
front axle and the shunt 28b. The locomotive 24b is also
introducing a signal into the railway track 26 both ahead of it and
behind it. As such, it is surveying the portion of railway track
between its rear axle and the shunt 28b, and the portion of railway
track between its front axle and the rear axle of locomotive 24c.
In the non-limiting example embodiment shown, the locomotive 24c is
only introducing a signal into the railway track ahead of it. As
such, locomotive 24c is only surveying the portion of the railway
track 26 between its front axle and the shunt 28c.
[0033] Although in the non-limiting example embodiment shown in
FIG. 4, locomotive 24c is only introducing a signal into the
railway track 26 ahead of it, it should be understood that it could
also introduce a signal into the railway track behind it. In such
as case, both the locomotive 24b and the locomotive 24c would be
introducing a signal into the portion of railway track positioned
between them, such that they are both surveying that portion of the
railway track 26. In such a case, it may be beneficial for the two
locomotives to introduce signals having two different frequencies
into the rail in order to avoid frequency collisions.
[0034] As will be described in more detail further on, the
monitoring entity 22 is operative for receiving location
information from each of the locomotives 24a, 24b and 24c such that
the monitoring entity 22 has a complete picture of where each
locomotive 24a, 24b and 24c is in relation to the track, and in
relation to each other. As such, when the monitoring entity 22
notices that there is a portion of track that is being monitored by
two locomotives (such as the portion of track positioned between
locomotive 24b and 24c) the monitoring entity 22 can issue signals
to each of these two locomotives in order to assign to each of the
locomotives a specific carrier frequency for the signals that that
locomotive transmits into, and receives from, the track 26.
Alternatively, the monitoring entity 22 can issue signals to only
one of the locomotives, such as locomotive 24c, for example, in
order to instruct that locomotive to stop transmitting a signal
into the track behind it. In such a case, the portions of the
railway track 26 being surveyed would be as shown in FIG. 4. In the
case where the monitoring entity 22 transmits signals to the
locomotives 24, the monitoring entity 22 would also include a
transmitter.
[0035] As such, it should be understood that the manner in which
the locomotives 24 survey the railway track 26 can be dependent on
the configuration of the tracks, or on the basis of the number of
locomotives 24 travelling on the track 26. The decision as to which
locomotives perform the surveying operation, and which transmitters
are used, can be predetermined, or can be dynamically controlled as
the locomotives 24 travel across the railway track 26. For example,
in the case where there are many locomotives 24 travelling across
the track 26, it may be determined that each locomotive 24 will
only transmit and receive track signals from their front ends.
Alternatively, it may be determined that only every second
locomotive 24 will perform the railway track surveying. In
accordance with a non-limiting example embodiment, the
co-ordination of the dynamically changing surveying operations will
be controlled by the monitoring entity 22, which is in
communication with each locomotive 24.
[0036] In yet another non-limiting example embodiment, it is
possible that one locomotive 24 transmits a signal into the rails,
and that another locomotive 24 receives the signal. As such, only
one locomotive transmits and only one locomotive receives.
[0037] Shown in FIG. 5 is a non-limiting block diagram of the
components of a locomotive 24 that perform the functionality of the
broken rail detection. As described above, the locomotive 24
includes the rail transmitter 30 and the rail receiver 32. The
locomotive 24 further includes a processing unit 40 and a
transceiver 42. The processing unit 40 includes a signal generation
unit 46 in communication with the transmitter 30, and a signal
detection unit 44 in communication with the receiver 32. In the
case where the locomotive 24 includes a transmitter 30 and a
receiver 32 at both the front and back of the locomotive, the
locomotive may include two processing units 40, one for each of the
transmitter/receiver pairs.
[0038] The transceiver 42 is operative for communicating over a
wireless communication link with the monitoring entity 22. It
should be appreciated that the transceiver 42 of the locomotive 24
and the receiver 21 of the monitoring entity 22 are operative to
communicate over a wireless communication link. In accordance with
a non-limiting example embodiment, this wireless communication link
is an RF communication link, however, other suitable communication
links could also be used without departing from the spirit of the
invention. In addition, although FIG. 5 shows the locomotive 24 as
having a transceiver 42, the locomotive 24 could instead have
included a separate receiver and transmitter for communicating with
the monitoring entity 22.
[0039] In operation, the signal generation unit 46 is operative for
generating a current or voltage signal for being introduced into
the rails by the transmitter 30. In the case where the signal being
generated is a current (audio) signal, the signal generation unit
46 may include a programmable selectable oscillator, such that the
frequency of the signal being introduced into the rails can be
selected. It should be understood that the frequency of the signal
generated by the signal generation unit 46 may be constant such
that it is always the same, or may be selected based on a set of
pre-programmed instructions stored in the memory unit 48.
Alternatively, the frequency of the signal generated by the signal
generation unit may be selected on the basis of a control signal
from the monitoring entity 22. As described above, this may occur
in the case where the frequency of the signals is selected in order
to avoid frequency collisions with signals originating from other
locomotives. Alternatively, in the case where the locomotives
travelling on the track 26 are able to communicate with one
another, and they are surveying the same portion of track, the
locomotives can communicate in order to establish different carrier
frequencies for their respective signals. Alternatively, in the
case where two different signals are travelling in the same portion
of railway track 26, the signal signatures can be used to
differentiate between the two signals. For example, the locomotives
may use a signal sorting techniques, such as signal signature
analysis, in order to differentiate the two signals travelling in
the track.
[0040] As described above, once the transmitter 30 has introduced
the signal into the closed loop of the railway tracks 26, the
receiver 32 receives this signal (assuming there are no breaks in
the rails). The signal detection unit 44, which is in communication
with the receiver 32 is operative for detecting from the receiver
32 the presence of the signal circulating in the rails. The signal
detection unit 44 is further operative to measure the signal
strength to help in determining the rail status. A weak signal may
indicate a deterioration of the railway track 26. Likewise, the
signal detection unit 44 may also detect the signal signature.
[0041] The receiver 32 may be a programmable selectable receiver
32, such that it is able to adjust the frequency of the signals it
is receiving. The programmable selectable receiver 32 can select
the frequency of signals to be received in the same manner as the
frequency of the signals generated by the signal generation unit 46
selects the frequency of signals to be transmitted.
[0042] In addition to detecting the presence of the track signal,
the processing unit 40 is also operative for detecting the location
of the locomotive 24 on the railway track 26 as it travels along.
This may be done in a variety of manners, such as those described
below.
[0043] In a non-limiting example embodiment, the locomotive 24 is
operative for determining its location based on track-side
positioning devices. For example, positioned along the railway
track 26 can be transponders, or some other type of wayside
information storage device. The transponders are located at various
positions along the railroad track 26 and include coded information
that is stored by tuned resonators. In order to read the coded
information from these transponders, one or more antennas 50, which
utilise a given frequency band and which emit an electromagnetic
wave in that frequency band are positioned on the locomotive 24. As
such, when the locomotive 24 transporting the one or more antennas
50 passes in the vicinity of a transponder, the antenna emits
electromagnetic waves in a frequency band to which the transponder
is tuned, such that the antenna's electromagnetic waves power the
transponder. This causes the resonator circuit in the transponder
to resonate, which results in the transmission of the data stored
therein. This data is received by the antenna 50 and is transmitted
to the signal detection unit 44 that is coupled to the antenna
50.
[0044] In accordance with this example, the locomotive 24 includes
a map of the railway track 26 that includes an indication of where
the transponders are located on the railway track, as well as their
associated coded information. This map can be stored in the memory
unit 48. As such, the processing unit 40 is operative to process
the coded information received from the antenna 50 in combination
with the map, such that it can determine its location on the
railroad track 26.
[0045] In an alternative non-limiting example embodiment, the
locomotive is operative to determine its location on the railroad
track 26 based on GPS technology. In this example, the processing
unit 40 would be equipped with a GPS receiver such that it can
receive GPS co-ordinates from a GPS satellite. These GPS
co-ordinates can then be plotted on a corresponding map (which
could be stored in the memory 48), such that the processing unit 40
could determine the locomotive's position on the railway track
26.
[0046] As shown in FIG. 6, and as described above, the locomotives
24a, 24b and 24c of the system 20 are in communication with the
monitoring entity 22, such that information can be transmitted
between the locomotives 24a, 24b and 24c and the monitoring entity
22. During normal operation, the locomotives 24a, 24b and 24c, are
operative for continually transmitting their location information
to the monitoring entity 22 via transceiver 42. In this manner, the
monitoring entity 22 is aware of the location of each locomotive
24a, 24b and 24c travelling in its region.
[0047] Referring to the flowchart of FIG. 7, the process of
surveying a portion of railway track that is performed by one or
more of locomotive 24a, 24b and 24c will be described.
[0048] At step 60, the receiver 32 receives the signal circulating
in the railway track 26 and the signal detection unit 44 monitors a
characteristic of this track signal, whether it is the presence of
the signal, the strength of the signal, or the signature of the
signal. As described above, the track signal can be introduced into
the rail by the locomotive 24 that is doing the signal monitoring,
by another locomotive 24 or even by the monitoring entity 22.
[0049] At step 62, the signal detection unit 44 continuously
monitors the characteristic of the track signal. In the case where
the characteristic of the track signal being monitored has not
changed, the receiver 32 and the signal detection unit 44 continue
to monitor the track signal.
[0050] In the case where the signal detection unit 44 detects that
the characteristic of the signal being received at receiver 32 has
changed, whether that is the presence of the signal, the strength
of the signal or the signature of the signal, the signal detection
unit 44 proceeds to step 64 where it generates a signal indicative
of a potentially broken rail. The generated signal can include an
indication as to whether it the broken rail was detected in front
of the locomotive or behind the locomotive. The signal detection
unit 44 then passes this signal to the transceiver 42, such that at
step 66, the transceiver 42 transmits the signal indicative of a
potential broken rail to the monitoring entity 22.
[0051] The signal indicative of a potentially broken rail can
include a variety of information. In accordance with a non-limiting
example embodiment, the signal indicative of a potential broken
rail advises the monitoring entity 22 of the portion of the railway
track 26 it was surveying, and thus in which portion of track there
could be a broken rail. For the sake of example, it is assumed that
locomotive 24b in FIG. 2 has issued a signal to the monitoring
entity 22 indicative of a potential broken rail.
[0052] In accordance with this example, the locomotive 24b includes
a map of the railway track 26 over which it is travelling. The map
may include the location of the shunts 28a, 28b and 28c on the
track, as well as the location of the switches and any other
relevant rail information. This map may be stored in the memory
unit 48, for example. The map may also be downloaded to the
locomotive 24b prior to its journey, or the map can be transmitted
to the locomotive 24b from the monitoring entity 22. In such as
scenario, as the train passes into a region covered by a different
monitoring entity 22, it is operative to receive a new map from the
new monitoring entity 22.
[0053] In accordance with this example, the monitoring entity 22 is
operative to transmit to the locomotive 24b information associated
with the railway track on which it is travelling.
[0054] For example, the monitoring entity 22 may transmit
information to the locomotive 24b indicative of the location of
shunts, the location of other locomotives travelling on the track
26, or the location of other items, such as switches located on the
track 26.
[0055] Therefore, as the locomotive 24b travels over the railway
track 26, it receives location information from the track-side
transponders (or GPS), such that it is able to confirm/determine
its position on the map, and also receives information indicative
of the position of upcoming shunts and other locomotives 24 from
the monitoring entity 22. This information is then stored in the
memory unit 48 of the processing unit 40. Based on all this
information the locomotive 24b has a complete picture of the things
shunting the track 26 both ahead of it and behind it. As such, the
locomotive 24b can accurately determine the portion of the railroad
track 26 that it is surveying, at any point in time.
[0056] Keeping with the example of locomotive 24b, and assuming
that the locomotive 24b is positioned in the location as shown in
FIG. 2, based on the information received from the track-side
transponders, and the information received from the monitoring
entity 22, the locomotive 24b would know that it is positioned
between shunt 28b and shunt 28c, and that locomotive 24c is
positioned between it and the shunt 28c. On the basis of this
information, the processing unit 40 would be able to determine that
it is surveying the portion of railway track 26 between its rear
axle and the shunt 28b, and the portion of railway track 26 between
its front axle and the rear axle of locomotive 24c. As such, in the
case where the locomotive 24b detects a change in the signal
characteristic being monitored, the signal indicative of a
potential broken rail that it transmits to the monitoring entity 22
is indicative that there is a potential broken rail in the portion
of railway track between its front axle and the rear axle of the
locomotive 24c.
[0057] In accordance with a non-limiting example embodiment, the
signal indicative of a potential broken rail that is sent from the
locomotive 24b to the monitoring entity 22 may simply be indicative
of a change in the characteristic of the track signal being
monitored. As mentioned above, this change in characteristic may be
the absence of the track signal, a decrease in signal strength or a
change in signal signature, among other possibilities. In such a
situation, the processing performed to determine the portion of
railway track being surveyed by the locomotive 24b is performed at
the monitoring entity 22 instead of at the locomotive 24b.
[0058] In such an example embodiment, the transceiver 42 shown in
FIG. 5 may simply be a transmitter, since the locomotive 24b does
not need to receive any railway track information from the
monitoring entity 22. Instead, the locomotive 24b is only aware of
its current location information, which is continually sent to the
monitoring entity 22, and that is has detected a change in the
track signal that is circulating in the railway track 26. The
locomotive 24b is not aware of the positioning of other
locomotives, or the positioning of the shunts on the railway track
26. Therefore, the locomotive 24b is not aware of the portion of
the railway track that it is surveying.
[0059] In such an example embodiment, upon receipt of the signal
indicative of a potential broken rail from the locomotive 24b, the
monitoring entity 22 is operative for processing the location
information from locomotive 24b in combination with the location
information of the other locomotives 24a and 24c, and the location
information associated with the shunts and switches located on the
railway track 26. Based on this information, the monitoring entity
22 is operative to determine the portion of railway track 26 that
was being surveyed by the locomotive 24b at the time the locomotive
24b sent the signal indicative of the potential broken rail.
[0060] For the sake of example, it is assumed that the locomotive
24b sends a signal indicative of a potential broken rail when it is
in the position on the railway track shown in FIG. 2. In such a
case, the monitoring entity 22 knows the position of locomotive
24b, and knows that locomotive 24c is positioned between locomotive
24b and the shunt 28b. Based on this information, the monitoring
entity 22 can determine that the portion of railway track being
surveyed by the locomotive 24b at the time it sent the signal
indicative of the potential broken rail, is the portion of railway
track 26 between the front axle of locomotive 24b, and the rear
axle of locomotive 24c. As such, the monitoring entity 22 is
operative for determining the portion of railway track 26 in which
there is a broken rail.
[0061] Regardless of whether the determination of the portion of
railroad track 26 being surveyed by the locomotive 24b is performed
by the locomotive 24b, or the monitoring entity 22, upon receipt of
a signal indicative of a potential break in the rail, the
monitoring entity 22 is operative to determine that there is a
broken rail in a portion of railway track 26 in its region. More
specifically, based on the signals received from all the
locomotives 24a, 24b and 24c travelling along the railway track 26,
the monitoring entity 22 is operative for determining a complete
picture of the condition of the railway track 26. Upon detection of
a broken rail within its region, the monitoring entity 22 may
forward this information to a central control unit that is in
communication with multiple monitoring entities 22, such that the
control unit can determine how to proceed. Alternatively, the
monitoring entity 22 may issue a signal to advise railway
maintenance workers that there is a potential broken rail in a
certain portion of the railway track. In this manner, the
maintenance workers can go to the specific section of railway track
identified and can then find the location of the broken rail, and
repair it.
[0062] As such, the monitoring entity 22 is operative for detecting
broken rails in the region of railway track in large part on the
basis of signals received from the locomotives 24a, 24b and 24c.
However, as shown in FIG. 6, the monitoring entity 22 may also use
conventional detectors 64 for detecting broken rails, in
combination with the methods described above. Conventional methods
of detecting a broken rail may be used in portions of the railway
track that include difficult physical layouts, such as switches,
that may cause a locomotive to provide a false broken rail reading.
For example, referring to FIG. 2, the monitoring entity 22 may use
the traditional broken rail detection techniques to detect broken
rails in the portion of railway track 26 between shunt 28c and 28d.
As described above, a conventional method of broken rail detection
involves a transmitter and a receiver that are either connected
directly to the monitoring entity 22, or that are connected to
wayside equipment that is then in turn connected to the monitoring
entity 22.
[0063] In a non-limiting example embodiment, as the locomotive 24c
passes the shunt 28c, the monitoring entity 22 may issue a signal
to the locomotive 24c advising the locomotive not to perform broken
rail detection in this region. Alternatively, in the case where the
locomotive 24c does continue to perform broken rail detection in
this region, when the monitoring entity 22 receives a signal
indicative of a broken rail from the locomotive 24c, the monitoring
entity 22 knows that there is a railway switch within this section
that may cause the locomotive 24c to detect a false broken rail.
Once the locomotive 24c has passed outside of this section, the
monitoring entity 22 would use the conventional equipment 64 to
determine whether there is in fact a broken rail within the
section. In this manner, the processing unit 23 of the monitoring
entity 22 may have to filter out false detection readings and
combine information received from multiple different sources, i.e.,
more than one locomotive, or a locomotive in combination with
conventional techniques, in order to determine whether there is a
broken rail in a portion of its railway track 26.
[0064] In addition, while the method of performing broken rail
detection using the locomotives works well while there are many
locomotives travelling on the railway track 26, in the case where
there are no locomotives travelling along the railway track 26, the
monitoring entity 22 may choose to perform broken rail detection
using a conventional method, which can easily survey large sections
of railway track 26 between shunts.
[0065] Those skilled in the art should appreciate that in some
non-limiting example embodiments of the invention, all or part of
the functionality previously described herein with respect to the
locomotive 24, and the monitoring entity 22, may be implemented as
pre-programmed hardware or firmware elements (e.g., application
specific integrated circuits (ASICs), electrically erasable
programmable read-only memories (EEPROMs), etc.) or other related
components.
[0066] In other non-limiting example embodiments of the invention,
all or part of the functionality of the locomotives 24, and the
monitoring entity 22 may be implemented as software consisting of a
series of instructions for execution by a computing unit. The
series of instructions could be stored on a medium which is fixed,
tangible and readable directly by the computing unit (e.g.,
removable diskette, CD-ROM, ROM, PROM, EEPROM or fixed disk) or the
instructions could be stored remotely but transmittable to the
computing unit via a modem or other interface device (e.g., a
communications adapter) connected to a network over a transmission
medium. The transmission medium may be either a tangible medium
(e.g., optical or analog communications lines) or a medium
implemented using wireless techniques (e.g., microwave, infrared or
other transmission schemes).
[0067] As shown in FIG. 5, the processing unit 40 of the locomotive
24 includes a memory 48 connected to both the signal generation
unit 46 and the signal detection unit 44 by a communication bus.
The memory 48 may include data and program instructions. The
processing unit 40 is adapted to process the data and the program
instructions in order to implement the method of performing broken
rail detection described herein and depicted in the drawings.
[0068] Although the present invention has been described in
considerable detail with reference to certain non-limiting example
embodiments thereof, variations and refinements are possible
without departing from the spirit of the invention. Therefore, the
scope of the invention should be limited only by the appended
claims and their equivalents.
* * * * *