U.S. patent application number 10/962328 was filed with the patent office on 2006-04-13 for system and method for self powered wayside railway signaling and sensing.
This patent application is currently assigned to General Electric Company. Invention is credited to David Michael Davenport, Lynn Ann DeRose, John Erik Hershey, Roland Sidney Sedziol, Charles Erklin Seeley, Kenneth Brakeley II Welles.
Application Number | 20060076461 10/962328 |
Document ID | / |
Family ID | 36144310 |
Filed Date | 2006-04-13 |
United States Patent
Application |
20060076461 |
Kind Code |
A1 |
DeRose; Lynn Ann ; et
al. |
April 13, 2006 |
System and method for self powered wayside railway signaling and
sensing
Abstract
System and method for self powered wayside railway signaling and
sensing. The system includes a power scavenging module and a power
utilizing module. The power scavenging module is configured to
convert an excitation of a rail into electrical power. The power
utilizing module is powered by the electrical power and is
configured to detect a predetermined characteristic in relation to
the rail, a train moving on the rail or an environment of the
railroad and to communicate data in relation to the predetermined
characteristic.
Inventors: |
DeRose; Lynn Ann;
(Gloversville, NY) ; Seeley; Charles Erklin;
(Niskayuna, NY) ; Davenport; David Michael;
(Niskayuna, NY) ; Sedziol; Roland Sidney;
(Niskayuna, NY) ; Hershey; John Erik; (Ballston
Lake, NY) ; Welles; Kenneth Brakeley II; (Scotia,
NY) |
Correspondence
Address: |
GENERAL ELECTRIC COMPANY;GLOBAL RESEARCH
PATENT DOCKET RM. BLDG. K1-4A59
NISKAYUNA
NY
12309
US
|
Assignee: |
General Electric Company
|
Family ID: |
36144310 |
Appl. No.: |
10/962328 |
Filed: |
October 12, 2004 |
Current U.S.
Class: |
246/122R |
Current CPC
Class: |
B61K 9/00 20130101 |
Class at
Publication: |
246/122.00R |
International
Class: |
B61C 11/00 20060101
B61C011/00 |
Claims
1. A railroad signaling system, comprising: a power scavenging
module configured to convert an excitation of a rail into
electrical power; at least one sensor coupled to said power
scavenging module and configured to detect a predetermined
characteristic in relation to at least one selected from the group
consisting of said rail, a train moving on said rail, an
environment of said railroad signaling system, and combinations
thereof; and circuitry coupled to said at least one sensor and
configured to receive a signal sent by said at least one sensor in
relation to said predetermined characteristic and communicate data
in relation to said predetermined characteristic.
2. The system according to claim 1, wherein said at least one
sensor comprises at least one broken rail sensor.
3. The system according to claim 1, wherein said at least one
sensor comprises at least one occupancy detector configured to
detect an occupancy status of said rail.
4. The system according to claim 1, wherein said predetermined
characteristic in relation to said train comprises a sequential
count of a plurality of at least one selected from the group
consisting of wheels, axles, railroad cars, and combinations
thereof of said train.
5. The system according to claim 1, wherein said predetermined
characteristic in relation to said train comprises a temperature of
at least one selected from the group consisting of an axle, a
wheel, a bearing, and combinations thereof of said train.
6. The system according to claim 1, wherein said predetermined
characteristic in relation to said train comprises an identity of
said train.
7. The system according to claim 1, wherein said predetermined
characteristic in relation to said train comprises a speed of said
train.
8. The system according to claim 1, wherein said predetermined
characteristic in relation to said environment comprises at least
one selected from the group consisting of wind speed, rainfall,
snowfall, earthquake, landslide, temperature, barometric pressure,
humidity, and combinations thereof.
9. The system according to claim 1, wherein said excitation
comprises at least one selected from the group consisting of a
vibration of said rail, a displacement of said rail, an
electromagnetic excitation of said rail, and combinations
thereof.
10. The system according to claim 9, wherein said power scavenging
module further comprises a transducer configured to convert said
excitation into at least one selected from the group consisting of
a voltage, a current, and combinations thereof.
11. The system according to claim 10, wherein said transducer
comprises a piezoelectric system configured to convert said
vibration of said rail into said at least one selected from the
group consisting of said voltage, said current, and combinations
thereof.
12. The system according to claim 11, wherein said piezoelectric
system is configured based on a cantilever design to convert said
vibration of said rail into said at least one selected from the
group consisting of said voltage, said current, and combinations
thereof.
13. The system of claim 12 wherein said cantilever design comprises
a temperature compensated flexural mode structure to maximize an
efficiency of said cantilever design.
14. The system according to claim 10, wherein said transducer
comprises a hydraulic system configured to convert said
displacement of said rail into said at least one selected from the
group consisting of said voltage, said current, and combinations
thereof.
15. The system according to claim 14, wherein said displacement
comprises a vertical displacement.
16. The system according to claim 10, wherein said transducer
comprises a electromagnetic system configured to convert said
electromagnetic excitation of said rail into said at least one
selected from the group consisting of said voltage, said current,
and combinations thereof.
17. The system according to claim 1, wherein said power scavenging
module further comprises a power storage system configured to store
said electrical power.
18. The system according to claim 17, wherein said power storage
system comprises a capacitor.
19. The system according to claim 17, wherein said power storage
system comprises a battery.
20. The system according to claim 1, wherein said power scavenging
module further comprises a power conditioning circuit comprising: a
rectifier to rectify said electrical power; and a regulator to
regulate said electrical power.
21. The system according to claim 1, wherein said circuitry further
comprises: a signal conditioning module coupled to said at least
one sensor and configured to condition said signal sent by said at
least one sensor in relation to said predetermined characteristic;
a controller coupled to said power scavenging module, said at least
one sensor and said signal conditioning module and configured to
control and coordinate activities of said power scavenging module,
said at least one sensor and said signal conditioning module; and
an output module coupled to said controller and configured to
receive a conditioned signal from said controller and to
communicate said data in relation to said predetermined
characteristic, wherein said controller is further configured to
control and coordinate activities of said output module.
22. The system according to claim 21, wherein said signal
conditioning module is further configured to convert said signal
sent by said at least one sensor to a digital form for further
analysis and storage.
23. The system according to claim 21, wherein said data comprises
data in relation to status of at least one selected from the group
consisting of a local signal, a visual signal, and combinations
thereof.
24. The system according to claim 21, wherein said data comprises
data in relation to position of at least one selected from the
group consisting of a gate, a switch, and combinations thereof.
25. The system according to claim 21, wherein said output module
further comprises a transmitter configured to send said data to a
remote location.
26. The system according to claim 25, wherein said remote location
comprises a railroad operations control center.
27. The system according to claim 26, wherein said railroad
operations control center is configured to process at least one
data stream and configured to create a high level decisioning
system based on integration of said at least one data stream with
said data communicated by said output module.
28. The system according to claim 27 wherein said at least one data
stream comprises at least one data stream related to at least one
selected from the group consisting of logistics, maintenance,
diagnostics, repair history, calibration, and combinations thereof
of said system.
29. The system according to claim 25, wherein said transmitter is
further configured to send said data to a train.
30. The system according to claim 25 further comprising a data
processing module configured to receive said data communicated by
said output module.
31. The system according to claim 30, wherein said data comprises
at least one selected from the group consisting of a vibration
signature, an electronic signature of said train, and combinations
thereof.
32. The system according to claim 31 further configured to process
said data based on a predetermined analysis technique.
33. The system according to claim 32, wherein said predetermined
analysis technique comprises a regression analysis technique.
34. The system according to claim 32, wherein said predetermined
analysis technique comprises a pattern recognition technique.
35. The system according to claim 32, wherein said predetermined
analysis technique comprises a counting technique.
36. The system according to claim 32, wherein said predetermined
analysis technique comprises a principal component analysis
technique.
37. The system according to claim 32, wherein said predetermined
analysis technique comprises a standard comparative analysis
technique.
38. The system according to claim 21, wherein said output module is
further configured to communicate based on a predetermined
communication protocol.
39. The system according to claim 38, wherein said predetermined
communication protocol comprises an advanced train control
system.
40. The system according to claim 21 further comprising a receiver
configured to receive a signal from a remote location.
41. The system according to claim 21, wherein said controller is
further configured to activate at least one selected from the group
consisting of a switch, a gate, a visual signal, and combinations
thereof.
42. The system according to claim 1, wherein said railroad
signaling system is packaged in a hollow tie located in a rail-bed
of said rail.
43. A railroad signaling system, comprising: a power scavenging
module configured to convert an excitation of a rail into
electrical power; at least one sensor coupled to said power
scavenging module and configured to detect a predetermined
characteristic in relation to at least one selected from the group
consisting of said rail, a train moving on said rail, an
environment of said railroad signaling system, and combinations
thereof; and circuitry coupled to said at least one sensor and
configured to receive a signal sent by said at least one sensor in
relation to said predetermined characteristic and communicate data
in relation to said predetermined characteristic.
44. The system according to claim 43, wherein said at least one
sensor comprises at least one broken rail sensor.
45. The system according to claim 43, wherein said excitation
comprises at least one selected from the group consisting of a
vibration of said rail, a displacement of said rail, an
electromagnetic excitation of said rail, and combinations
thereof.
46. The system according to claim 43, wherein said power scavenging
module further comprises a transducer configured to convert said
excitation into at least one selected from the group consisting of
a voltage, a current, and combinations thereof.
47. The system according to claim 43, wherein said power scavenging
module further comprises a power conditioning circuit comprising: a
rectifier to rectify said power; and a regulator to regulate said
power.
48. The system according to claim 42, wherein said circuitry
further comprises: a signal conditioning module coupled to said at
least one sensor and configured to condition said signal sent by
said at least one sensor in relation to said predetermined
characteristic; a controller coupled to said power scavenging
module, said at least one sensor and said signal conditioning
module and configured to control and coordinate activities of said
power scavenging module, said at least one sensor and said signal
conditioning module; and an output module coupled to said
controller and configured to receive a conditioned signal from said
controller and to communicate said data in relation to said
predetermined characteristic, wherein said controller is further
configured to control and coordinate activities of said output
module.
49. The system according to claim 48, wherein said signal
conditioning module is further configured to convert said signal
sent by said at least one sensor to a digital form for further
analysis and storage.
50. The system according to claim 48, wherein said output module
further comprises a transmitter configured to send said data to a
remote location.
51. A railroad signaling system, comprising: a power scavenging
module configured to convert an excitation of a rail into
electrical power; at least one sensor coupled to said power
scavenging module and configured to detect a predetermined
characteristic in relation to at least one selected from the group
consisting of said rail, a train moving on said rail, an
environment of said railroad signaling system, and combinations
thereof; a signal conditioning module coupled to said at least one
sensor and configured to condition a signal sent by said at least
one sensor; a controller coupled to said power scavenging module,
said at least one sensor and said signal conditioning module and
configured to control and coordinate activities of said power
scavenging module, said at least one sensor and said signal
conditioning module; and an output module coupled to said
controller and configured to receive a conditioned signal from said
controller and to communicate data in relation to said
predetermined characteristic detected by said at least one sensor,
wherein said controller is further configured to control and
coordinate activities of said output module.
52. A system for generating local power on railroad, comprising: a
power scavenging module configured to convert an excitation of a
rail into electrical power; and a power utilizing module powered by
said electrical power.
53. A method for railroad signaling, comprising: generating power
from an excitation of a rail and using said power to energize at
least one sensor; sensing a predetermined characteristic in
relation to at least one selected from the group consisting of said
rail, a train moving on said rail, an environment of said railroad
signaling using said power, and combinations thereof; conditioning
a signal generated based on said sensing of said predetermined
characteristic; and communicating data in relation to said
predetermined characteristic.
54. The method according to claim 53, wherein said sensing
comprises sensing electrically.
55. The method according to claim 53, wherein said predetermined
characteristic in relation to said rail comprises a break in said
rail.
56. The method according to claim 53, wherein said predetermined
characteristic in relation to said rail comprises an occupancy
status of said rail.
57. The method according to claim 53, wherein said predetermined
characteristic in relation to said train comprises a sequential
count of at least one selected from the group consisting of a
plurality of axles, a plurality of wheels, a plurality of railroad
cars, and combinations thereof of said train.
58. The method according to claim 53, wherein said predetermined
characteristic in relation to said train comprises a temperature of
at least one selected from the group consisting of an axle, a
wheel, a bearing, and combinations thereof of said train.
59. The method according to claim 53, wherein said predetermined
characteristic in relation to said train comprises an identity tag
of said train.
60. The method according to claim 53, wherein said predetermined
characteristic in relation to said train comprises a speed of said
train.
61. The method according to claim 53, wherein said predetermined
characteristic in relation to said environment comprises at least
one selected from the group consisting of wind speed, rainfall,
snowfall, earthquake, landslide, temperature, barometric pressure,
humidity, and combinations thereof.
62. The method according to claim 53, wherein said generating power
comprises: positioning a power scavenging module on said rail;
converting power from said excitation of said rail; and storing
said power electrically.
63. The method according to claim 62, wherein said converting power
comprises converting power from at least one selected from the
group consisting of a vibration of said rail, a displacement of
said rail, an electromagnetic excitation of said rail, and
combinations thereof.
64. The method according to claim 63, wherein said displacement is
a vertical displacement.
65. The method according to claim 62, wherein said converting power
comprises converting power into at least one selected from the
group consisting of a voltage, a current, and combinations
thereof.
66. The method according to claim 53, further comprising
conditioning said power.
67. The method according to claim 66, wherein said conditioning
said power comprises rectifying said power.
68. The method according to claim 67, wherein conditioning said
power comprises regulating said power.
69. The method according to claim 53, wherein said conditioning a
signal further comprises converting said signal to a digital form
for further analysis and storage.
70. The method according to claim 53, wherein communicating data
comprises communicating status of at least one selected from the
group consisting of a local signal, a visual signal, and
combinations thereof.
71. The method according to claim 53, wherein communicating data
comprises communicating position of at least one selected from the
group consisting of a gate, a switch, and combinations thereof.
72. The method according to claim 53, wherein communicating data
comprises communicating based on a predetermined communication
protocol.
73. The method according to claim 72, wherein said predetermined
communication protocol comprises an advanced train control
system.
74. The method according to claim 53, further comprising receiving
said data.
75. The method according to claim 53, further comprising
transmitting said data to a remote location.
76. The method according to claim 75, further comprising processing
said data based on a predetermined analysis technique.
77. The method according to claim 76, wherein said data comprises
at least one selected from the group consisting of a vibration
signature, an electronic signature, and combinations thereof.
78. The method according to claim 77, wherein said vibration
signature comprises at least two vibration signatures from two
different rails.
79. The method according to claim 76, wherein said predetermined
analysis technique comprises regression analysis technique.
80. The method according to claim 76, wherein said predetermined
analysis technique comprises a pattern recognition technique.
81. The method according to claim 76, wherein said predetermined
analysis technique comprises a counting technique.
82. The method according to claim 76, wherein said predetermined
analysis technique comprises a principal component analysis
technique.
83. The method according to claim 76, wherein said predetermined
analysis technique comprises a standard comparative analysis
technique.
84. The method according to claim 53, further comprising receiving
a signal from a remote location.
85. The method according to claim 53, further comprising activating
at least one selected from the group consisting of a switch, a
gate, a visual signal, and combinations thereof.
86. A method for railroad signaling, comprising: generating power
from an excitation of a rail and using said power to energize at
least one sensor; sensing a predetermined characteristic in
relation to at least one selected from the group consisting of said
rail, a train moving on said rail, an environment of said railroad
signaling, and combinations thereof using said at least one sensor;
conditioning a signal generated based on said sensing of said
predetermined characteristic; and communicating data in relation to
said predetermined characteristic.
87. The method according to claim 86, wherein said generating power
comprises: positioning a power scavenging module on said rail;
converting power from said excitation of said rail; and storing
said power electrically;
88. The method according to claim 87, wherein said converting power
comprises converting power from at least one selected from the
group consisting of a vibration of said rail, a displacement of
said rail, an electromagnetic excitation of said rail, and
combinations thereof.
89. The method according to claim 86, further comprising
conditioning said power.
90. The method according to claim 89, wherein conditioning said
power comprises rectifying said power.
91. The method according to claim 86, wherein said conditioning a
signal further comprises converting said signal to a digital form
for further analysis and storage.
92. The method according to claim 86 further comprising
transmitting said data to a remote location.
93. A method for generating local power on railroad, comprising:
generating power from an excitation of a rail; and energizing a
power utilizing module using said power.
Description
BACKGROUND
[0001] This invention relates to a wayside sensor for railroads.
More particularly this invention relates to a system for the
reading of a sensor, processing the sensor output data and
communicating the data in a wireless manner through the use of a
power scavenging module.
[0002] Wayside sensors for railroad operations perform a variety of
functions. Because wires must be run to each sensor for
communication and electrical power, this results in significant
installation costs and maintenance costs as well as reliability
concerns.
[0003] Accordingly, there is a need in the art to provide a more
effective method and system for wireless rail sensing systems
specifically augmented by use of a localized power generation
system.
BRIEF DESCRIPTION
[0004] In accordance with one embodiment of the present invention,
a system for generating local power on railroad is provided. In
this embodiment, the system includes a power scavenging module and
a power utilizing module. The power scavenging module is configured
to convert an excitation of a rail into electrical power. The power
utilizing module is powered by the electrical power and is
configured to detect a predetermined characteristic in relation to
the rail or a train moving on the rail or an environment of the
railroad and to communicate data in relation to the predetermined
characteristic.
[0005] In accordance with another embodiment of the invention, a
method is provided for generating local power on railroad. The
method includes generating power from an excitation of a rail and
energizing a power utilizing module using the power to detect a
predetermined characteristic in relation to the rail or a train
moving on the rail or an environment of the railroad and
communicate data in relation to the predetermined
characteristic.
DRAWINGS
[0006] FIG. 1 is a perspective view of a railroad signaling system
constructed in accordance with an exemplary embodiment of the
invention that includes a power scavenging module, a sensor module,
a signal conditioning module and an output module for data
communication.
[0007] FIG. 2 is a block diagram of a railroad signaling system
constructed in accordance with an exemplary embodiment of the
invention that includes a power scavenging module, a sensor module,
a signal conditioning module and an output module for data
communication and
[0008] FIG. 3 illustrates a method for railroad signaling in
accordance with an exemplary embodiment of the invention.
DETAILED DESCRIPTION
[0009] FIG. 1 illustrates a perspective view of a railroad
signaling system 10 constructed in accordance with an exemplary
embodiment of the invention that includes a power scavenging module
12, a sensor module 14, a signal conditioning module 16 and an
output module 18. In this embodiment, power scavenging module 12,
sensor module 14, signal conditioning module 16 and output module
18 are depicted as four different components. In other embodiments,
however, these components can be combined into one or more
integrated signaling system(s). The principles of the invention are
not limited to only railroad systems. One of ordinary skill will
recognize that other embodiments of the invention are suited for
other types of detection systems, for example, systems to detect
flaws in various types of rails used for track guided vehicles that
are generally installed at amusement parks and rails used for
tramways.
[0010] According to one embodiment of the invention as described in
FIG. 1, when a train passes over a point in the rail 28, a downward
force is applied to the rails at the contact points with the wheels
because of the weight of the train. The rail deflects in a downward
motion as a result of this force. As the wheel passes and another
wheel approaches, the rail deflects upward due to bending of the
rail between wheels. This motion typically occurs at low frequency
(0.1-10 Hz). Considerable rail vibration is also induced at higher
frequency (>10 Hz) in both horizontal and vertical directions
due to the passing train. The power scavenging module 12 utilizes
one or both of the low and high frequency motions of the rail to
generate electrical charge and a resultant voltage differential
across its two output nodes. The voltage is tapped using contacts
to power other systems that are electrically coupled to the output
nodes of the power scavenging module 12. The power scavenging
module 12 and a power utilizing module together complete an
electrical circuit that receives and conducts the current resulting
from the power scavenging module 12.
[0011] In one embodiment of the invention, the power utilizing
module is the sensor module 14 that senses various operational
parameters in relation to integrity of the rail and the train. In
another embodiment of the invention, the power utilizing module is
the signal conditioning module 16 that receives the output signals
from the sensor module 14 and then converts these signals into
digital form for further analysis and storage. In yet another
embodiment of the invention, the power utilizing module is the
output module 18 that receives conditioned signals from the signal
conditioning module 16 and then communicates the resulting data to
a control unit. Each of these elements--the power scavenging module
12, the sensor module 14, the signal conditioning module 16 and the
output module 18 will be described in more detail below.
[0012] FIG. 2 is a detailed block diagram of a railroad signaling
system 10 constructed in accordance with an exemplary embodiment of
the invention. Power scavenging module 12 typically includes a
transducer 44, a power conditioning circuit 46 and a power storage
system 48. A transducer is a system that converts energy from one
input form to another output form. In one embodiment of the
invention as illustrated in FIG. 2, the input excitation for the
transducer 44 is a vibration or a displacement of the rail as a
train passes over that and the output is electrical energy. In this
embodiment, transducer 44 includes a vibrating device that is made
of piezoelectric material. Typically, piezoelectric materials
deform due to the application of a physical force and the
mechanical energy of this deformation is converted into electrical
energy. This phenomenon is known in the art as `piezoelectric
effect.`
[0013] In one embodiment of the invention, the power producing
piezoelectric transducer 88 is attached to the rail 28 of FIG. 1
either directly, or via an intermediate mechanical device used to
amplify the effects of the rail vibration provided by a passing
train. As a result of the force from the passing trains, electrical
charges are generated across the two output nodes of the
piezoelectric transducer 88. Converting the output electrical
energy of the piezoelectric transducer 88 into useful electric
power typically requires several steps. In one embodiment, the
output electrical energy of the piezoelectric transducer 88 is
transformed into a DC voltage and a current in a power conditioning
circuit 46 comprising a rectifier 96 and a regulator 98. The
regulated DC output of the power conditioning circuit 46 is
temporarily stored in a storage system 48 and then used by the
sensor module 14, the signal conditioning module 16 or the output
module 18.
[0014] Technical details of piezoelectric transducer 88 are known
to persons skilled in the art and the specifics are not disclosed
herein. Different embodiments of the railroad signaling system 10
of the present invention are herein described. However, it should
be understood that the different modes for carrying out the
invention hereinafter described are offered by way of illustration
and not by the way of limitation. It is intended that the scope of
the invention include all modifications that incorporate its
principal design features.
[0015] The mechanical, electrical, physical and other properties of
a particular piezoelectric transducer 88 determine the amount of
electrical charge that is generated in response to a given applied
force. The polarity of the generated charge on the other hand
depends on whether the element is under compression or tension as a
result of the externally applied force. The amount of electrical
charge generated and the impedance of the external system that uses
the power affect the voltages developed at the contacts, leads and
nodes of the power scavenging module 12.
[0016] Functionally, in other embodiments of the invention, the
stressing of the piezoelectric transducer 88 is done by subjecting
the piezoelectric transducer 88 to a force or a stress or a strain
in a single, multiple or other impulsive manner or in a cyclical or
other repetitive manner. This is done either at a constant
frequency or any other frequency or range of frequencies found to
be desirable. If efficiency of energy harvesting device depends
upon resonant quality factor that may vary with ambient
temperature, a temperature compensated flexural mode structure may
be incorporated to retain a high quality factor independent of
temperature.
[0017] In this embodiment of the invention, the piezoelectric
transducer 88 is configured based on a cantilever design and
specifically a temperature compensated flexural mode structure
maximizes the efficiency of the cantilever design. Moreover, the
piezoelectric transducer 88 is designed to function near its
resonance mode by appropriately choosing the dimensions. In a
resonant state, the mechanical energy applied on the piezoelectric
transducer 88 is transformed very efficiently into electrical
energy. The resonance frequency varies as a function of a number of
properties of the piezoelectric transducer 88 e.g., the size,
shape, density and other physical parameters. The factors affecting
resonance also include the constituent makeup, for example, the
basic crystal constituents and the various additives used to
provide and vary the piezoelectric properties of the crystal or
crystals being employed.
[0018] Operationally, in yet another embodiment of the invention,
the piezoelectric transducer 88 is made of materials that include
thin polymer films, single crystal materials, or other
piezoelectric element structures. These materials are used to form
structures that are easily excited from a vibration input. This
input may be a single discrete frequency, a combination of
frequencies, or broadband vibration with a very large number of
frequencies. The shape, size, density and other physical parameters
of the materials and geometry of the structure have a direct impact
on the efficiency of the piezoelectric structure to convert
mechanical energy into electrical energy. These parameters are
chosen to design the most efficient system obtainable.
[0019] In other embodiments of the invention, other systems such as
hydraulic transducers, electromagnetic transducers and other types
of transducers are considered for different alternative
configurations of the power scavenging module 12 based on
operational parameters such as `performance` as measured in terms
of power output, `cost`, `ease of installation`, `environmental
impact`, `reliability` etc. Various types of power scavenging
modules produce different amounts of voltage and current. Various
internal and external parameters are used to match the internal
impedance of the power scavenging module 12 with the external
impedance of the power utilizing modules like the sensor module 14,
the signal conditioning module 16 or the output module 18. In an
`impedance-matched` state, the overall flexibility and performance
of the railroad signaling system 10 is improved.
[0020] Referring to FIG. 2 again, one other embodiment of the
invention employs a hydraulic transducer 92 as a displacement
transducer. The hydraulic transducer 92 uses hydraulic fluid to
scavenge energy from passing trains using the low frequency
displacement of the rail as the rail car trucks pass overhead. In
operation, when a train passes over the rails, a downward force
compresses the rails and the ties relative to the ballast. This
relative motion and force depresses the hydraulic transducer 92 and
pressurizes its hydraulic flow circuit. A pilot valve (not shown)
controls the release of hydraulic fluid under high pressure into a
motor or a generator (not shown) where the mechanical energy is
converted into electrical energy using an associated rectifier and
regulator electronics. The hydraulic fluid exits into a reservoir
where it is stored until it is needed for successive cycles. The
hydraulic transducer 92 also serves as an energy storage system
holding the pressurized hydraulic fluid until power is actually
needed. Energy storage systems will be described in more detail
later. A return spring returns the hydraulic transducer 92 to its
original position after an energy producing cycle.
[0021] In another embodiment of the invention, the input excitation
to the transducer 44 in FIG. 2 is an electromagnetic excitation. An
electromagnetic vibratory, linear-velocity transducer 94 is built
from a coil (not shown) attached to the vibrating rails and a
permanent magnet (not shown) that is suspended within the coil by a
spring. When the frequency of vibration of the coil exceeds the
resonance frequency of the coil-magnet mechanical system, the
magnet remains almost immovable. At that time, a voltage is
generated across the coil due to the motion of the turns of the
coil in the magnetic field of the permanent magnet. The voltage is
proportional to the speed of the coil.
[0022] Referring back to FIG. 2, the power generated by the
different embodiments of the power scavenging module 12 is
conditioned, first by rectifying and then by regulating the power
so that the power is usable. Power conditioning circuit 46 includes
rectifier 96 and regulator 98. The rectifier 96 receives the
alternating electrical current from the piezoelectric transducer 88
and produces a corresponding pulsating direct current (DC) output.
The electrical current rectified by the rectifier 96 is regulated
by a voltage regulator 98. The regulator 98 maintains the output
voltage at a constant level for a range of input voltages.
[0023] In one embodiment, the regulator 98 is a shunt-type voltage
regulator. A shunt regulator using a zener diode is the simplest
and least expensive alternative. Shunt regulators keep the voltage
across them to a maximum constant value, when a very low current is
allowed to flow through it. In an alternative embodiment of the
invention, a series regulator is used in the power conditioning
circuit 46. The series regulator employs an impedance in series to
drop any extra voltage between the generator and the impedance
itself. Both the series and the shunt regulators are dissipative in
nature and they both operate in step down mode. In another
embodiment of the invention, a switching regulator is used in the
power conditioning circuit 46, when the power generated is much
higher than required. Switching regulators employ a switching
element in their power regulating circuit and they operate in both
step up and step down modes. Switching regulators need a very low
current to maintain a high constant input voltage. Moreover, they
need over-voltage protection in the form of a low current zener
diode.
[0024] Referring to FIG. 2 again, the power conditioned in the
power conditioning circuit 46 is typically stored in a power
storage system 48. Power storage system 48 typically includes
battery 102 and/or capacitor 104 to receive and store the regulated
electrical output coming from regulator 98. Such output is smoothed
in voltage and has a nearly constant value. The energy is typically
stored in a battery 102 for long term use or stored in a capacitor
104 for short term use. There are systems like wireless sensors
that are required to transmit data at regular intervals for
relatively short times. When such systems depend on the power
scavenging module 12 for operating power, energy stored in the
battery 102 or the capacitor 104 is used.
[0025] There are various types of batteries 102 available. The
factors to be considered while selecting a battery for the power
storage system 48 are capacity, leakage current and number of
charge-discharge cycles possible during the lifetime of the
battery. Capacity of a battery is decided based on the load
current, as the maximum current that is drawn depends on the
`Ampere-hour` rating of the battery and the charging current
available from the power generator e.g., the power scavenging
module 12 in the case of this embodiment of the invention. `Leakage
current of a battery` determines how much of electrical energy is
lost from the battery and whether the battery will remain in a
charged state for considerably long time. The battery used in this
embodiment is a Lithium-ion Battery. The advantage of using such
batteries is their high capacity and low leakage. That ensures that
the voltage rarely falls below the required level and hence there
is low startup time.
[0026] Referring to FIG. 2 again, the power generated by the power
scavenging module 12 is subsequently utilized by the sensor module
14. The sensor module 14 senses one or more operational parameters
related to the integrity of the rail or a train passing over the
rails. The sensor module 14 may include a broken rail detector 52
to detect any breakage or fissure in the rails, an occupancy
detector 54 to detect the presence of a train over a block or
sector of rails or a train characteristics detector 56 to detect a
number of characteristic parameters such as number of wheels or
axles or railroad cars of a train or temperature of wheels or axles
or bearings of the train passing over the rails. The sensor module
14 may also be enabled to determine the speed of a train. The
sensor module 14 may also include defect detectors such as dragging
equipment, hot bearing, hot wheel or wheel impact load. The sensor
module 14 may further include an `Automatic Equipment
Identification` (AEI) tag reader system to detect an identity of a
train. These sensors are well known to those familiar with
state-of-the-art in railway signaling.
[0027] The technical details of sensor module 14 and the sensing
process therein are known to persons skilled in the art and
specifics are not disclosed herein. The different embodiments and
modes of sensing contemplated for the sensor module 14 of the
present invention are herein described. It should be understood
that the invention is not limited to the above-described
configuration of the sensor module 14. The best mode for carrying
out the invention hereinafter described is offered by way of
illustration and not by the way of limitation. It is intended that
the scope of the invention include all modifications that
incorporate its principal design features.
[0028] In another embodiment of the invention, the sensor module 14
may include sensing systems to sense the status of a local signal
or a visual signal. In yet another embodiment of the invention,
sensor module 14 may include sensing systems to sense the position
of a gate or a switch. In another embodiment of the invention, the
sensor module 14 may include sensing systems to senses
environmental characteristics such as wind speed, rainfall,
snowfall, earthquake, landslide, temperature, barometric pressure,
humidity etc.
[0029] Referring to FIG. 2 again, in one embodiment of the
invention, the power generated by the power scavenging module 12 is
utilized by a circuitry 15 that is coupled to the sensor module 14
and is configured to receive the output signals of the sensor
module 14. The circuitry 15 also communicates data in relation to
the rail or train or environmental characteristics sensed by the
sensor module 14. The circuitry 15 includes the signal conditioning
module 16. The signal conditioning module 16 receives the signals
obtained by the sensor module 14 and processes them. In operation,
the functions of the signal conditioning module 16 include analog
amplification, gating, digital signal capture, signal processing
and digital data analysis and processing. This module provides
additional functionalities for power management, duty cycle, analog
to digital conversion, time stamp, digital memory and environmental
compensation.
[0030] Another element of the circuitry 15 as illustrated in FIG. 2
is a controller 22. The power scavenging module 12, the sensor
module 14 and the signal conditioning module 16 communicate with
the controller 22. The controller 22 includes a microcontroller
(not shown) and it is the central unit that controls and
coordinates all the activities of all the modules of the railroad
signaling system 10 and thereby coordinates the overall functioning
of the system 10. The controller 22 is an analog-to-digital
converter accessible through all types of analog input ports and
the function of the controller 22 is to convert the input analog DC
voltage to a digital format recognizable by a central processing
unit located in a command control circuit or a remote control unit.
A number of switches, gates and visual signals are part of any
typical railroad signaling system and controller 22 activates
various switches using command module 122, various gates using
command module 124 and various visual signals using command module
126. The controller 22 also controls and coordinates the activities
of the output module 18 and sends the conditioned signal coming
from the signal conditioning module 16 to the output module 18. The
structure and the function of the output module 18 will be
described in more details below.
[0031] The invention is not limited to the above-described
configuration of the controller 22. In other embodiments of the
invention, the controller 22 includes other solid-state equipments,
relays, microprocessors, software, hardware, firmware, etc. or
combinations thereof. All the read-out logic circuits in the system
10 also communicate with the controller 22 and the controller 22 in
turn activates appropriate fail-time or warning alerts if the
threshold level of an excitation from the broken rail detector 52
or the occupancy detector 54 or the train characteristics detector
56 is exceeded. The command signals issued by controller 22 take
the form of simple go/no-go decisions wherein proper and improper
performances are differentiated. Alternatively, more robust
information is developed depending upon the type of situation being
monitored, the sophistication of the sensor involved and logic
performed by controller 22. For example, a history of field or
performance data is recorded with future performance being
predicted on the basis of the data trend. For audio performance
data, the information includes volume, frequency, and pattern of
sound verses time. For visual performance data, the information
includes wavelength, visual images, intensity and pattern of light
verses time. One should appreciate that the information stored by
the controller 22 is directly responsive to known failure modes and
performance characteristics of the particular type of railroad
situation being monitored.
[0032] Referring to FIG. 2 again, the circuitry 15 also includes
the output module 18. The output module 18 receives the processed
signals from the controller 22 and then transmits them to a control
unit. Hardware options for transmission include radio or wired
communication links and transceivers or plug-in memory extension
cards. Moreover, an Internet or other multi-media communication
links are especially useful for this application to facilitate
convenient access to the information by a plurality of interested
parties and to facilitate two-way communication. There are various
communication protocols for use in various communications modes
depending on the specific embodiment of this module. The output
module 18 in this embodiment includes a receiver 72 and a
transmitter 66 to communicate with the controller 22 or with a
command control circuit (not shown) or with a wayside bungalow (not
shown). Both receiver 72 and transmitter 66 are enabled to
communicate using the necessary modes of communication protocol.
Typical examples of communication protocols include TCP/IP and
railroad standardized `Automatic Train Control System` (ATCS).
[0033] An alternative to the embodiment described above is the use
of a remote control unit 26 to control the operations of the
railroad signaling system 10 remotely. The remote control unit 26
typically includes and makes use of access to the Internet or other
wide area information networks. The receiver 72 of the output
module 18, in this embodiment, receives communication signals from
the controller 22 or from the remote control unit 26 or from the
command control circuit (not shown) or from the wayside bungalow
(not shown). In the same manner, the output module 18, in this
embodiment communicates with the remote control unit 26.
Functionally, the remote control unit 26 includes a
microcontroller, such as a computerized data processor or an analog
micro controller that receives the communication signals from the
output module 18.
[0034] In an alternative embodiment, the remote control unit 26
includes a transmitter (not shown) and a remote receiver (not
shown). The transmitter and the receiver can communicate in one or
more of wireless, landline and fiber optic communication modes.
Corresponding units housed in the output module 18 for two-way
communication are the receiver 72 and the transmitter 66. The
readiness of railroad signaling system 10 throughout the network is
easily and automatically monitored by the remote control unit 26.
In another embodiment of the invention, the remote control unit 26
has an additional database to store various operational and field
maintenance data in relation to various components, subsystems of
the railroad signaling system 10. For instance, data regarding the
make, model, location, installation date, service history etc. of
each component or each subsystem throughout the network are
maintained in the database. Similar communication in relation to
operation of the various components or subsystems of the railroad
signaling system 10, such as the power scavenging module 12, the
sensor module 14, the signal conditioning module 16 or the output
module 18 is transmitted from the remote control unit 26 to the
railroad signaling system controller 22 via the output module
18.
[0035] In yet another embodiment of the invention, the remote
control unit 26 includes communication equipments located on a
passing train, so that communication signals are conveyed between
the remote control unit 26 and the output module 18 using a
transmitter or a receiver positioned in the train. In yet another
alternative embodiment, remote control unit 26 communicates with a
remotely located operations control center (not shown) so that
appropriate warnings are provided to trains moving on the rail line
regarding a breakage in the rails or a malfunction of a component
or a subsystem. Approaching trains are signaled to stop or to
proceed at a slow speed in such eventualities. Data streams from
other systems can also be incorporated in to the operations control
center such as logistics and maintenance and diagnostics systems to
create a higher level of decisioning for the rail companies.
Decisions can be made concerning scheduling based on the data
streams of maintenance records, location of the train, jobs in the
queue, asset location etc. In another embodiment of the invention,
decisions can be made based on integration of the data streams
mentioned above with the data communicated by said output module.
In similar manner, decisions for occupancy and consist can be
optimized as well as alerts for security etc.
[0036] In an alternative embodiment, the system 10 also includes a
data processing unit 24. Referring to FIG. 2 again, the remote
control unit 26 communicates with the data processing unit 24 for a
higher-level analysis of the data processed and transmitted by the
controller 22. The data processing unit 24 includes a train
signature analysis module 132 and a statistical data analysis
module 134. Train signature analysis module 132 analyzes vibration
signatures or electronic signatures of a train as detected by the
train characteristics detector 56 using statistical techniques like
regression analysis, pattern recognition techniques, counting
technique, principal component analysis etc. and compares the
vibration signatures or electronic signatures to standard
signatures using various comparative analysis techniques. On the
other hand, the statistical data analysis module 134 performs a
number of statistical analysis techniques on the data stored in the
controller 22 and accessed using remote control unit 26. For
instance, in one embodiment, a trending analysis of `mean time
between failure` (MTBF) of various components is performed. In
another embodiment, a change in the time interval between the
delivery of a test signal and the operation of a component or a
subsystem are used to diagnose a developing problem. An early
recognition of a change in the system characteristics permits
problems to be addressed before they result in a condition wherein
a component or a subsystem fails to respond in a safe manner.
[0037] In other embodiments of the invention, analysis techniques
performed by the data processing unit 24 involves numeric
processing including computation of average values, peak values,
time-to-maximum values, minimum values, time-to-minimum values,
root mean square (RMS) values, cycle time, frequency, rise time,
fall time, area values, integer values, pulse width, duty cycle,
specified level time, differential pulse count of various sensing
signals and their interpretation in various railroad related events
such as acceleration or deceleration or stoppage of a train. In yet
another embodiment of the data processing unit 24, algorithms are
developed that relate a typical vibration signature of a train as
detected by the train characteristics detector 56 and the power
output of the power scavenging module 12 to other railroad related
events such as a train stopping, accelerating, idling etc. In the
event when the vibration signature of a train changes, it is
possible to use the power scavenging module 12 and the train
characteristics detector 56 in tandem to detect a possibility of a
breakage in the rails. In such an event, the data processing unit
24 analyzes the data and communicates with the controller 22 via
the remote control unit 26 to activate an appropriate warning
signal switch. It is also be possible to compare vibration
signatures of a train from both the rails and identify a breakage
in the rails by analyzing the difference between the two signals
from two different rails.
[0038] The invention is not limited to the above-described
stand-alone configuration of the railroad signaling system 10. In
another embodiment of the invention, the railroad signaling system
10 may be configured specifically for on-site use and it may be
packaged in a hollow tie located in a rail-bed.
[0039] The overall operation of the system 10 is illustrated in
FIG. 3 using a process flow chart for railroad signaling in
accordance with an exemplary embodiment of the invention. A power
scavenging module is positioned directly on the rail as in step 142
to generate power from various excitations of the rails using
various transducers as in step 144. Converting power from various
excitations of the rails includes converting power from vibrational
excitations as in step 146 or converting power from displacement
excitations as in step 148 or converting power from electromagnetic
excitations as in step 152. The power is converted into voltage
form as in step 154 and into current form as in step 156. The power
converted by the different embodiments of the power scavenging
module is conditioned as in step 158, first by rectifying as in
step 162 and then by regulating the power as in step 164 so that
the power is usable. The power conditioned this way is then stored
in a power storage system as in step 166.
[0040] The transducers and the power storage system together ensure
that there is sufficient power available all the time to operate
all the other modules of the railroad signaling system 10. This
way, drawing power either directly from the transducers or from the
power storage system, the sensor module 14 is activated for sensing
various operational parameters of passing trains, of the rails and
a number of environmental characteristics as in step 168. More
specifically, sensing operational parameters includes sensing any
broken rail as in step 172, sensing block occupancy as in step 174
and sensing train characteristics as in step 176. In another
embodiment of the invention, sensing operational parameters
includes sensing status of a local signal or a visual signal. In
yet another embodiment of the invention, sensing operational
parameters includes sensing position of a gate or a switch. In
another embodiment of the invention, sensing operational parameters
includes sensing environmental characteristics such as wind speed,
rainfall, snowfall, earthquake, landslide, temperature, barometric
pressure, humidity etc. The output signals from the sensor module
are next conditioned as in step 178 for further analysis and
storage. Typically, the conditioning of the signals takes place by
conversion of the analog output signals from the sensor modules
into digital form.
[0041] Referring back to FIG. 3, direct power from the transducers
or stored power from the storage system is used to operate an
output module that receives the signals of sensed train and rail
status and environmental characteristics and from the controller as
in step 182. The controller is a central unit that controls and
coordinates all the activities, such as converting power from
various excitations of the rails as in step 144, sensing various
operational parameters of any passing train, rail as well as a
number of environmental characteristics as in step 168,
conditioning of the sensed signals as in step 178 and communicating
with the output module of the railroad signaling system 10 as in
step 182. Moreover, a number of switches, gates and visual signals
are part of any typical railroad signaling system and the
controller activates these various switches, gates and visual
signals as in step 186.
[0042] On the other hand, the operation of the output module
further includes communicating with a remote control unit as in
step 184. The output module communicates data related to all
operational parameters to the remote control unit and receives
command signals from the remote control unit and then passes that
on to the controller. The controller processes the command signals
to control and monitor various functions of the railroad signaling
system 10. The communication between the output module and the
remote control unit, as in step 184, takes place via landline or
wireless means. The remote control unit also communicates with a
data processing unit. The data processing unit processes various
operational data related to the train and the rail as in step 188.
Processing of the operational data includes processing train
signatures as in step 192 and processing various statistical data
related to the operation of the train and the rail as in step
194.
[0043] In essence, the different embodiments described above make
this invention a self-powered, flexible, surface mountable, small,
lightweight, cost effective, mass producible system. All the
subcomponents are typically housed in a hollow railroad tie and can
be rapidly deployed in the rail bed eliminating the need of any
separate bungalows or AC line power.
[0044] While only certain features of the invention have been
illustrated and described herein, many modifications and changes
will occur to those skilled in the art. It is, therefore, to be
understood that the appended claims are intended to cover all such
modifications and changes as fall within the true spirit of the
invention.
* * * * *