U.S. patent application number 16/609228 was filed with the patent office on 2020-06-11 for advanced preemption.
The applicant listed for this patent is Siemens Mobility, Inc.. Invention is credited to Richard Alan McGavock, Jr..
Application Number | 20200180670 16/609228 |
Document ID | / |
Family ID | 59054302 |
Filed Date | 2020-06-11 |
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United States Patent
Application |
20200180670 |
Kind Code |
A1 |
McGavock, Jr.; Richard
Alan |
June 11, 2020 |
ADVANCED PREEMPTION
Abstract
An advanced preemption system may comprise at least one motion
detector and at least one advanced preemption processing system in
communication with the at least one motion detector. The at least
one motion detector may be configured to detect motion within at
least one motion detection zone, the at least one motion detection
zone containing a section of railroad track outside of a track
circuit containing a railroad crossing where a thoroughfare crosses
the railroad track. The at least one advanced preemption processing
system may be configured to receive, from the at least one motion
detector, an indication that motion has been detected within the at
least one motion detection zone and activate at least one traffic
control element for the thoroughfare before a train enters the
track circuit.
Inventors: |
McGavock, Jr.; Richard Alan;
(Columbia, MO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Siemens Mobility, Inc. |
New York |
NY |
US |
|
|
Family ID: |
59054302 |
Appl. No.: |
16/609228 |
Filed: |
June 2, 2017 |
PCT Filed: |
June 2, 2017 |
PCT NO: |
PCT/US2017/035579 |
371 Date: |
October 29, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B61L 3/02 20130101; B61L
25/02 20130101; B61L 27/0077 20130101; B61L 29/22 20130101; B61L
29/30 20130101; B61L 29/228 20130101; B61L 29/32 20130101; B61L
29/28 20130101 |
International
Class: |
B61L 29/22 20060101
B61L029/22; B61L 29/32 20060101 B61L029/32; B61L 25/02 20060101
B61L025/02; B61L 29/30 20060101 B61L029/30; B61L 27/00 20060101
B61L027/00; B61L 3/02 20060101 B61L003/02 |
Claims
1. An advanced preemption system comprising: at least one motion
detector configured to detect motion within at least one motion
detection zone, the at least one motion detection zone containing a
section of railroad track outside of a track circuit containing a
railroad crossing where a thoroughfare crosses the railroad track;
and at least one advanced preemption processing system in
communication with the at least one motion detector and configured
to: receive, from the at least one motion detector, an indication
that motion has been detected within the at least one motion
detection zone; and activate at least one traffic control element
for the thoroughfare before a train enters the track circuit.
2. The system of claim 1, wherein the at least one motion detector
comprises at least one camera.
3. The system of claim 1, wherein the at least one advanced
preemption processing system comprises an event recorder configured
to receive the indication and generate an advanced preemption
output in response to the indication.
4. The system of claim 3, wherein the event recorder is further
configured to log the indication in a memory.
5. The system of claim 1, wherein the at least one advanced
preemption processing system comprises train detection equipment
configured to generate a preemption output in response to the
indication.
6. The system of claim 5, wherein the train detection equipment is
further configured to generate the preemption output in response to
the track circuit detecting a train on the track circuit.
7. The system of claim 1, wherein the at least one traffic control
element comprises crossing access control equipment configured to
selectively control access to the railroad crossing from the
thoroughfare, the system further comprising crossing activation
equipment configured to activate the crossing access control
equipment in response to the indication.
8. The system of claim 1, wherein the at least one traffic control
element comprises at least one traffic signal for the thoroughfare,
the system further comprising traffic signal control equipment
configured to control the at least one traffic signal in response
to the indication.
9. The system of claim 1, wherein: the least one advanced
preemption processing system is further configured to start a timer
in response to a train leaving the track circuit; and activate the
at least one traffic control element in response to both the
indication and an expiration of the timer.
10. The system of claim 1, wherein: the least one advanced
preemption processing system is further configured to start a timer
in response to the indication; and activate the at least one
traffic control element in response to both the indication and an
expiration of the timer.
11. The system of claim 1, further comprising the track circuit,
the at least one traffic control element, or a combination
thereof.
12. An advanced preemption method comprising: detecting, by at
least one motion detector, motion within at least one motion
detection zone, the at least one motion detection zone containing a
section of railroad track outside of a track circuit containing a
railroad crossing where a thoroughfare crosses the railroad track;
receiving, by at least one advanced preemption processing system in
communication with the at least one motion detector, an indication
from the at least one motion detector that motion has been detected
within the at least one motion detection zone; and activating, by
the at least one advanced preemption processing system, at least
one traffic control element for the thoroughfare before a train
enters the track circuit.
13. The method of claim 12, further comprising: receiving, by an
event recorder of the at least one advanced preemption processing
system, the indication; and generating, by the event recorder, an
advanced preemption output in response to the indication.
14. The method of claim 13, further comprising logging, by the
event recorder, the indication in a memory.
15. The method of claim 12, further comprising: generating, by
train detection equipment of the at least one advanced preemption
processing system, a preemption output in response to the
indication.
16. The method of claim 15, further comprising generating, by the
train detection equipment, the preemption output in response to the
track circuit detecting a train on the track circuit.
17. The method of claim 12, wherein the at least one traffic
control element comprises crossing access control equipment
configured to selectively control access to the railroad crossing
from the thoroughfare, the method further comprising activating, by
crossing activation equipment of the at least one advanced
preemption processing system, the crossing access control equipment
in response to the indication.
18. The method of claim 12, wherein the at least one traffic
control element comprises at least one traffic signal for the
thoroughfare, the method further comprising controlling, by
crossing activation equipment of the at least one advanced
preemption processing system, the at least one traffic signal in
response to the indication.
19. The method of claim 12, further comprising: starting, by the
least one advanced preemption processing system, a timer in
response to a train leaving the track circuit; and activating, by
the least one advanced preemption processing system, the at least
one traffic control element in response to both the indication and
an expiration of the timer.
20. The method of claim 12, further comprising: starting, by the
least one advanced preemption processing system, a timer in
response to the indication; and activating, by the least one
advanced preemption processing system, the at least one traffic
control element in response to both the indication and an
expiration of the timer.
Description
BACKGROUND
[0001] Railroad tracks cross other paths, such as roads and
walkways, at railroad crossings. As a train approaches a railroad
crossing, train detection systems detect the train and prepare the
railroad crossing. For example, traffic signals on either side of
the crossing can indicate the approach of the train (e.g., by
turning red), crossing gates and lights can be activated (e.g.,
gates are lowered and warning lights flash), and/or audible alarms
(e.g., bells) can sound. Generally, the train is detected by a
track circuit, which detects the train by detecting a short between
parallel rails caused by a conductive train axle on the rails. For
example, a track circuit can be arranged to extend some distance
beyond a railroad crossing in either direction of the track, and
when the track circuit detects a train on that portion of the
track, crossing signals and gates activate. This is known as
preemption.
SUMMARY OF THE DISCLOSURE
[0002] Systems and methods described herein may provide advanced
preemption by detecting a train before it reaches a track circuit
associated with a railroad crossing. For example, some embodiments
described herein may deploy sensors such as motion-sensing cameras
beyond the ends of the track circuit. These sensors may detect a
train as it approaches the track circuit area, detecting the train
before it enters the track circuit. Advanced preemption may improve
railroad crossing safety through earlier and more reliable train
detection, allowing crossing signals and gates to activate earlier
and/or allowing additional warnings such as traffic signals
positioned at a distance from the railroad crossing. Advanced
preemption systems and methods described herein may be inexpensive,
compact, and more easily set up compared with installing additional
track circuits in series with the track circuit at the railroad
crossing, for example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is a block diagram of a railroad crossing according
to an embodiment of the invention.
[0004] FIG. 2 is a block diagram of an advanced preemption element
architecture according to an embodiment of the invention.
[0005] FIGS. 3-5 are advanced preemption processes according to an
embodiment of the invention.
DETAILED DESCRIPTION OF SEVERAL EMBODIMENTS
[0006] Systems and methods described herein may combine camera
technology with train predictors and/or event recorders to provide
an advanced preemption indication to traffic signaling equipment.
For example, motion detecting cameras may be set up past the
boundaries of railroad crossing track circuit(s) in order to detect
train motion and send an advanced preemption indication to railroad
crossing and/or traffic signaling equipment.
[0007] FIG. 1 is a block diagram of a railroad crossing 100
according to an embodiment of the invention. Railroad crossing 100
may be an area where the railroad crosses another thoroughfare such
as a road 101. Crossing access control equipment 102 may be
installed at railroad crossing 100 to prevent collisions between
traffic on the railroad and traffic on the road 101. For example,
crossing access control equipment 102 may include gates that close
and lights that flash when a train is approaching and/or crossing
at railroad crossing 100. Traffic signals 104, such as traffic
lights, may be disposed along the road 101 at a distance further
removed from the railroad crossing 100 than the crossing access
control equipment 102. The advanced preemption systems and methods
described herein may enable control of traffic signals 104 when a
train is approaching and/or crossing at railroad crossing 100, as
described below.
[0008] Railroad crossing 100 may include one or more track circuits
configured to detect the presence of a train and perform
preemption. The track circuits may include island circuit 106
configured to detect the train in the immediate vicinity of the
road 101 (e.g., on the portion of the track that crosses the road
101 itself) and track circuit 108 configured to detect the train in
the area of the track extending out from railroad crossing 100.
Island circuit 106 and track circuit 108 may each be
communicatively coupled to crossing access control equipment 102,
for example by wires (not shown). Island circuit 106 and/or track
circuit 108 may detect a train by detecting a short between
parallel rails caused by a conductive train axle on the rails. When
a train is detected, island circuit 106 and/or track circuit 108
may send a signal to crossing access control equipment 102 causing
crossing access control equipment 102 to activate (e.g., causing
gates to close and/or lights to flash). In some embodiments, island
circuit 106 and/or track circuit 108 may send a signal to equipment
in crossing equipment bungalow 120, as discussed below, which in
turn may control crossing access control equipment 102.
[0009] Railroad crossing 100 may benefit from advanced preemption
in addition to the basic preemption provided by island circuit 106,
track circuit 108, and crossing access control equipment 102.
Advanced preemption equipment may include one or more motion
detecting cameras 112 (in this example, two cameras 112a and 112b)
configured to monitor one or more motion detection zones 110 (in
this example, two zones 110a and 110b). Motion detecting cameras
112 are discussed in the examples herein, but any other motion
detecting technology (e.g., radar, etc.) may be used. Motion
detecting cameras 112 may be configured to monitor multiple motion
detection zones 110. In some embodiments, each motion detecting
cameras 112 may be configured to monitor up to ten motion detection
zones 110 (e.g., for areas wherein multiple tracks are in use).
This feature may reduce cost and complexity by allowing for the
installation of fewer cameras.
[0010] Motion detecting cameras 112 may be configured to detect
motion and generate an output in response to detecting motion. For
example, motion detecting cameras 112 may capture images in
response to detecting motion and/or output a signal indicating the
presence of motion within motion detection zones 110. In some
embodiments, motion detecting cameras 112 may transmit outputs to
external equipment (e.g., equipment in crossing equipment bungalow
120) using various protocols (e.g., SNMP, HTTP, HTTPS, etc.)
through integrated and/or separate wireless devices or buried
Ethernet cable. In some embodiments, motion detecting cameras 112
may transmit outputs to external equipment (e.g., equipment in
crossing equipment bungalow 120) using a direct wire connection
(e.g., supplying a high voltage in response to detecting motion and
a low voltage otherwise, or supplying a low voltage in response to
detecting motion and a high voltage otherwise). Motion detecting
cameras 112 may utilize onboard digital relay outputs with buried
cable in some embodiments. Motion detecting cameras 112 may be
powered locally with power over Ethernet or using integrated and/or
separate solar, battery, or other power sources. Motion detecting
cameras 112 may be non-vital systems in some embodiments, because
the track circuit 108 and island circuit 106 provide a vital system
for closing railroad crossing 100 that is installed in conjunction
with motion detecting cameras 112.
[0011] Motion detecting cameras 112 may transmit outputs to
equipment in crossing equipment bungalow 120. Crossing equipment
bungalow 120 may contain equipment used to control and monitor
crossing access control equipment 102 and, in some embodiments,
traffic signals 104. For example, crossing equipment bungalow 120
may include event recorder 122, office communication equipment 126,
crossing activation equipment 128, and/or train detection equipment
130. Each of these elements may be embodied as one or more
dedicated circuits or processors and/or one or more software
modules contained in a memory and executed by a processor.
[0012] Vehicle traffic signal control box 114 may contain equipment
used to control and monitor traffic signals 104, such as traffic
signal control equipment 116. For example, traffic signal control
equipment 116 may be in communication with equipment in crossing
equipment bungalow 120, and the respective elements may work
together to control traffic signals 104 in response to motion
detected by one or more motion detecting cameras 112. These
elements may communicate with one another using various protocols
(e.g., SNMP, HTTP, HTTPS, etc.) through integrated and/or separate
wireless devices or buried Ethernet cable, or through direct wire
connections sending a high or low voltage signal, for example. In
some embodiments, each traffic signal 104 may be controlled by a
separate vehicle traffic signal control box 114. Vehicle traffic
signal control box 114 may be coupled to and/or integrated with
traffic signals 104, for example. In some embodiments, vehicle
traffic signal control box 114 may control multiple traffic signals
104. Vehicle traffic signal control box 114 may be in communication
with multiple traffic signals 104 from a single location, and may
be collocated with crossing equipment bungalow 120 in some
cases.
[0013] The equipment in crossing equipment bungalow 120 and/or
vehicle traffic signal control box 114 may control crossing access
control equipment 102 and/or traffic signals 104 when a train is in
the vicinity of the railroad crossing 100. For example, when motion
detecting camera 112 detects motion, it may send output (e.g., a
message using a protocol or a voltage on a direct wire) to event
recorder 122. Event recorder 122 may perform further processing and
output advanced preemption data 124. Event recorder 122 may perform
other functions, such as logging each motion detection event and/or
logging track circuit 108 and/or island circuit 106 events. Train
detection equipment 130 may receive advanced preemption data 124,
perform further processing, and generate preemption data 118. Train
detection equipment 130 may also receive signals from island
circuit 106 and/or track circuit 108 (e.g., signals indicating the
presence of a train) and control crossing access control equipment
102 based on these signals. Train detection equipment 130 may
generate preemption data 118 based on the signals from island
circuit 106 and/or track circuit 108 as well in some embodiments.
Traffic signal control equipment 116 may receive preemption data
118 and control traffic signals 104. Example embodiments of this
process is described in detail in FIGS. 3-5 below.
[0014] In some embodiments, crossing equipment bungalow 120 can
include office communication equipment 126. Office communication
equipment 126 may be configured to communicate status of other
equipment in crossing equipment bungalow 120 and/or vehicle traffic
signal control box 114 to a central office. For example, office
communication equipment 126 may report on the status of the
equipment periodically and/or report in the event of failure of any
of the equipment.
[0015] FIG. 2 is a block diagram of an advanced preemption element
architecture 200 according to an embodiment of the invention. In
some embodiments, one or more of traffic signal control equipment
116, event recorder 122, office communication equipment 126,
crossing activation equipment 128, and train detection equipment
130 may be implemented partially or entirely by one or more
computer systems. FIG. 2 shows an example computer architecture 200
that may provide any of these elements or a combination
thereof.
[0016] Architecture 200 may be implemented on any electronic device
that runs software applications derived from compiled instructions.
In some implementations, architecture 200 may include one or more
processors 202, one or more input devices 204, one or more power
supplies 206, one or more network interfaces 208, and one or more
computer-readable mediums 210. Each of these components may be
coupled by bus 212.
[0017] Power supply 206 may be any power supply technology,
including connection to a power grid, renewable source, battery, or
combination thereof. Input device 204 may be any input device
technology, including but not limited to a human interface such as
a keyboard, mouse, touchpad, etc. and/or a device interface such as
a direct connection to equipment (e.g., a connection to motion
detecting camera 112). Bus 212 may be any internal or external bus
technology, including but not limited to ISA, EISA, PCI, PCI
Express, NuBus, USB, Serial ATA or FireWire. Computer-readable
medium 210 may be any medium that participates in providing
instructions to processor(s) 202 for execution, including without
limitation, non-volatile storage media (e.g., optical disks,
magnetic disks, flash drives, etc.), or volatile media (e.g.,
SDRAM, ROM, etc.).
[0018] Computer-readable medium 210 may include various
instructions 214 for implementing an operating system (e.g., Mac
OS.RTM., Windows.RTM., Linux). The operating system may be
multi-user, multiprocessing, multitasking, multithreading,
real-time, and the like. The operating system may perform basic
tasks, including but not limited to: recognizing input from input
device 204; keeping track of files and directories on
computer-readable medium 210; controlling peripheral devices (e.g.,
crossing access control equipment 102, traffic signals 104, etc.)
which can be controlled directly or through an I/O controller; and
managing traffic on bus 212. Network communications instructions
216 may establish and maintain network connections (e.g., software
for implementing communication protocols, such as TCP/IP, HTTP,
Ethernet, etc.).
[0019] Preemption system equipment instructions 218 can include
instructions that may implement one or more of traffic signal
control equipment 116, event recorder 122, office communication
equipment 126, crossing activation equipment 128, and train
detection equipment 130. For example, preemption system equipment
instructions 218 may be used to perform some or all parts of the
process of FIG. 3 discussed below.
[0020] Application(s) 220 may be an application that uses or
implements the processes described herein or other processes. The
processes may also be implemented in operating system 214.
[0021] The described features may be implemented in one or more
computer programs that may be executable on a programmable system
including at least one programmable processor coupled to receive
data and instructions from, and to transmit data and instructions
to, a data storage system, at least one input device, and at least
one output device. A computer program is a set of instructions that
can be used, directly or indirectly, in a computer to perform a
certain activity or bring about a certain result. A computer
program may be written in any form of programming language (e.g.,
Objective-C, Java), including compiled or interpreted languages,
and it may be deployed in any form, including as a stand-alone
program or as a module, component, subroutine, or other unit
suitable for use in a computing environment.
[0022] Suitable processors for the execution of a program of
instructions may include, by way of example, both general and
special purpose microprocessors, and the sole processor or one of
multiple processors or cores, of any kind of computer. Generally, a
processor may receive instructions and data from a read-only memory
or a random access memory or both. The essential elements of a
computer may include a processor for executing instructions and one
or more memories for storing instructions and data. Generally, a
computer may also include, or be operatively coupled to communicate
with, one or more mass storage devices for storing data files; such
devices include magnetic disks, such as internal hard disks and
removable disks; magneto-optical disks; and optical disks. Storage
devices suitable for tangibly embodying computer program
instructions and data may include all forms of non-volatile memory,
including by way of example semiconductor memory devices, such as
EPROM, EEPROM, and flash memory devices; magnetic disks such as
internal hard disks and removable disks; magneto-optical disks; and
CD-ROM and DVD-ROM disks. The processor and the memory may be
supplemented by, or incorporated in, ASICs (application-specific
integrated circuits).
[0023] FIG. 3 is an advanced preemption process 300 according to an
embodiment of the invention. Advanced preemption system elements of
FIG. 1 may work together to perform this process 300 to help
prevent accidents at railroad crossing 100. This example process
300 is for a single track with two motion detection zones 110
outside the boundaries of track circuit 108, as shown in FIG. 1,
although it may be applied to railroad crossings 100 with different
configurations as well. Process 300 may begin when there is no
train on track circuit 108.
[0024] At 302, track circuit 108 may deactivate. As those of
ordinary skill in the art understand, track circuit 108 may be
configured to detect a train by detecting a short between parallel
rails of the track. The short is caused by a train's conductive
axle contacting both rails. When the rails are shorted, track
circuit 108 may be regarded as active (e.g., having a train
thereon). Accordingly, track circuit 108 deactivation may indicate
a transition from an active state, where there is a short between
the rails, to an inactive state where the rails are not
electrically coupled. Track circuit 108 may communicate its state
to event recorder 122. When track circuit 108 deactivates, event
recorder 122 may start a track circuit inactive timer. The track
circuit inactive timer may expire after a certain period of time.
The period of time may be customized based on the properties of
each individual track (e.g., track speeds, distances between motion
detection zones 110 and track circuit 108, size of track circuit
108, customer preference, etc.).
[0025] At 304, railroad crossing 100 may be inactive. Railroad
crossing 100 may be inactive when no preemption equipment (e.g.,
island circuit 106, track circuit 108, and/or motion detecting
camera(s) 112) is detecting the presence of a train.
[0026] At 306, one or more motion detecting cameras 112 may detect
motion. For example, motion detecting camera 112a may detect motion
within its associated motion detection zone 110a, and/or motion
detecting camera 112b may detect motion within its associated
motion detection zone 110b. It will be appreciated from FIG. 1 that
motion detecting cameras 112 may detect motion caused by a train
entering motion detection zones 110 before the train shorts
parallel rails in track circuit 108.
[0027] At 308, event recorder 122 may receive data indicating
motion detection from at least one motion detecting camera 112. For
example, as noted above, motion detecting cameras 112 may be
connected wirelessly or by wire to equipment in crossing equipment
bungalow 120, including event recorder 112. Event recorder 122 may
receive messages from motion detecting cameras 112 indicating
motion in associated motion detection zones 110.
[0028] At 310, event recorder 122 may start an advanced preemption
timer if the track circuit inactive timer has expired. As noted
above, the track circuit inactive timer starts when a train first
moves off track circuit 108. The train may need time to travel
beyond track circuit 108, through motion detection zone 110, and
beyond. Accordingly, while the train circuit inactive timer is
running, the advanced preemption system may be expecting motion in
motion detection zone 110 from the known train passing through
motion detection zone 110. Thus, event recorder 112 may start the
advanced preemption timer only after the track circuit inactive
timer has expired.
[0029] At 312, event recorder 122 may activate its advanced
preemption output 124. Train detection equipment 130 may detect
this advanced preemption output 124 from event recorder 112.
[0030] At 314, in response to detecting advanced preemption output
124, train detection equipment 130 may activate its preemption
output 118. Traffic signal control equipment 116 may detect this
preemption output 118 from train detection equipment 130.
[0031] At 316, traffic signal control equipment 116 may adjust
traffic signals 104 in response to receiving preemption output 118.
For example, traffic signal control equipment 116 may hold traffic
signals 104 at red while preemption output 118 is active to prevent
traffic from moving into railroad crossing 100. In some
embodiments, crossing activation equipment 128 may also receive
preemption output 118 and control crossing access control equipment
102 in response to receiving preemption output 118. However, in
other embodiments, because preemption output 118 may be based on
input from a non-vital system (e.g., motion detecting cameras 112),
crossing activation equipment 128 may control crossing access
control equipment 102 only in response to track circuit 108 and/or
island circuit 106 detecting the presence of a train.
[0032] In the example of FIG. 3, traffic signal control equipment
116 receives preemption output 118 from train detection equipment
130, which in turn receives advanced preemption output 124 from
event recorder 122. As noted above, train detection equipment 130
may also control crossing access control equipment 102 in response
to detecting a train on track circuit 108 and/or island circuit
106. Routing preemption data through train detection equipment 130
to traffic signal control equipment 116 may allow the advanced
preemption system to be installed at railroad crossings 100 where
train detection equipment 130 and track circuit 108/island circuit
106 systems are already in place, using the same train detection
equipment 130 to perform basic track circuit-based preemption and
advanced preemption. Routing preemption data through train
detection equipment 130 to traffic signal control equipment 116 may
also coordinate control of traffic signals 104 and crossing access
control equipment 102. However, in some embodiments, step 314 may
be skipped, and traffic signal control equipment 116 may receive
advanced preemption output 124 directly from event recorder 122 at
step 316.
[0033] At 318, track circuit 108 may activate as the train moves
past motion detection zone 110 and onto track circuit 108.
[0034] At 320, island circuit 106 may activate as the train moves
onto island circuit 106.
[0035] At 322, island circuit 106 may deactivate as the train moves
off island circuit 106. At this point, the train may be clear of
railroad crossing 110.
[0036] At 324, in response to deactivation of island circuit 106,
all preemption signals (e.g., advanced preemption output 124,
preemption output 118) may deactivate, indicating that railroad
crossing 100 is now safe to cross.
[0037] At 326, in response to deactivation of preemption signals,
crossing access control equipment 102 and traffic signals 104 may
resume normal operation, allowing traffic from the thoroughfare to
enter railroad crossing 100.
[0038] Returning to 310, the advanced preemption timer may expire
if track circuit 108 does not activate within a certain period of
time. The period of time may be customized based on the properties
of each individual track (e.g., track speeds, distances between
motion detection zones 110 and track circuit 108, size of track
circuit 108, customer preference, etc.). The advanced preemption
timer may expire without track circuit 108 activating in cases
where a train enters motion detection zone 110 and stops before
reaching track circuit 108. Event recorder 122 may not activate its
advanced preemption output 124 when the advanced preemption timer
is not active (e.g., after it expires). This may prevent
unnecessary activation of crossing access control equipment 102
and/or traffic signals 104 when the train does not reach railroad
crossing 100.
[0039] FIG. 4 is an advanced preemption process 400 according to an
embodiment of the invention. Advanced preemption system elements of
FIG. 1 may work together to perform this process 400 to help
prevent accidents at railroad crossing 100. This example process
400 is for a single track with two motion detection zones 110
outside the boundaries of track circuit 108, as shown in FIG. 1,
although it may be applied to railroad crossings 100 with different
configurations as well. Process 400 may begin when there is no
train on track circuit 108.
[0040] At 402, track circuit 108 may deactivate. As those of
ordinary skill in the art understand, track circuit 108 may be
configured to detect a train by detecting a short between parallel
rails of the track. The short is caused by a train's conductive
axle contacting both rails. When the rails are shorted, track
circuit 108 may be regarded as active (e.g., having a train
thereon). Accordingly, track circuit 108 deactivation may indicate
a transition from an active state, where there is a short between
the rails, to an inactive state where the rails are not
electrically coupled. Track circuit 108 may communicate its state
to train detection equipment 130. When track circuit 108
deactivates, train detection equipment 130 may start a track
circuit inactive timer. The track circuit inactive timer may expire
after a certain period of time. The period of time may be
customized based on the properties of each individual track (e.g.,
track speeds, distances between motion detection zones 110 and
track circuit 108, size of track circuit 108, customer preference,
etc.).
[0041] At 404, railroad crossing 100 may be inactive. Railroad
crossing 100 may be inactive when no preemption equipment (e.g.,
island circuit 106, track circuit 108, and/or motion detecting
camera(s) 112) is detecting the presence of a train.
[0042] At 406, one or more motion detecting cameras 112 may detect
motion. For example, motion detecting camera 112a may detect motion
within its associated motion detection zone 110a, and/or motion
detecting camera 112b may detect motion within its associated
motion detection zone 110b. It will be appreciated from FIG. 1 that
motion detecting cameras 112 may detect motion caused by a train
entering motion detection zones 110 before the train shorts
parallel rails in track circuit 108.
[0043] At 408, train detection equipment 130 may receive data
indicating motion detection from at least one motion detecting
camera 112. For example, as noted above, motion detecting cameras
112 may be connected wirelessly or by wire to equipment in crossing
equipment bungalow 120, including train detection equipment 130.
Train detection equipment 130 may receive messages from motion
detecting cameras 112 indicating motion in associated motion
detection zones 110. Train detection equipment 130 may communicate
with event recorder 122 so event recorder 122 can record the motion
detection event.
[0044] At 410, train detection equipment 130 may start an advanced
preemption timer if the track circuit inactive timer has expired.
As noted above, the track circuit inactive timer starts when a
train first moves off track circuit 108. The train may need time to
travel beyond track circuit 108, through motion detection zone 110,
and beyond. Accordingly, while the train circuit inactive timer is
running, the advanced preemption system may be expecting motion in
motion detection zone 110 from the known train passing through
motion detection zone 110. Thus, train detection equipment 130 may
start the advanced preemption timer only after the track circuit
inactive timer has expired.
[0045] At 412, train detection equipment 130 may activate its
preemption output 118. Traffic signal control equipment 116 may
detect this preemption output 118 from train detection equipment
130.
[0046] At 414, traffic signal control equipment 116 may adjust
traffic signals 104 in response to receiving preemption output 118.
For example, traffic signal control equipment 116 may hold traffic
signals 104 at red while preemption output 118 is active to prevent
traffic from moving into railroad crossing 100. In some
embodiments, crossing activation equipment 128 may also receive
preemption output 118 and control crossing access control equipment
102 in response to receiving preemption output 118. However, in
other embodiments, because preemption output 118 may be based on
input from a non-vital system (e.g., motion detecting cameras 112),
crossing activation equipment 128 may control crossing access
control equipment 102 only in response to track circuit 108 and/or
island circuit 106 detecting the presence of a train.
[0047] In the example of FIG. 4, traffic signal control equipment
116 receives preemption output 118 from train detection equipment
130. As noted above, train detection equipment 130 may also control
crossing access control equipment 102 in response to detecting a
train on track circuit 108 and/or island circuit 106. Routing
preemption data through train detection equipment 130 to traffic
signal control equipment 116 may allow the advanced preemption
system to be installed at railroad crossings 100 where train
detection equipment 130 and track circuit 108/island circuit 106
systems are already in place, using the same train detection
equipment 130 to perform basic track circuit-based preemption and
advanced preemption. Routing preemption data through train
detection equipment 130 to traffic signal control equipment 116 may
also coordinate control of traffic signals 104 and crossing access
control equipment 102.
[0048] At 416, track circuit 108 may activate as the train moves
past motion detection zone 110 and onto track circuit 108.
[0049] At 418, island circuit 106 may activate as the train moves
onto island circuit 106.
[0050] At 420, island circuit 106 may deactivate as the train moves
off island circuit 106. At this point, the train may be clear of
railroad crossing 110.
[0051] At 422, in response to deactivation of island circuit 106,
all preemption signals (e.g., preemption output 118) may
deactivate, indicating that railroad crossing 100 is now safe to
cross.
[0052] At 424, in response to deactivation of preemption signals,
crossing access control equipment 102 and traffic signals 104 may
resume normal operation, allowing traffic from the thoroughfare to
enter railroad crossing 100.
[0053] Returning to 410, the advanced preemption timer may expire
if track circuit 108 does not activate within a certain period of
time. The period of time may be customized based on the properties
of each individual track (e.g., track speeds, distances between
motion detection zones 110 and track circuit 108, size of track
circuit 108, customer preference, etc.). The advanced preemption
timer may expire without track circuit 108 activating in cases
where a train enters motion detection zone 110 and stops before
reaching track circuit 108. Train detection equipment 130 may not
activate its advanced preemption output 124 when the advanced
preemption timer is not active (e.g., after it expires). This may
prevent unnecessary activation of crossing access control equipment
102 and/or traffic signals 104 when the train does not reach
railroad crossing 100.
[0054] FIG. 5 is an advanced preemption process 400 according to an
embodiment of the invention. Advanced preemption system elements of
FIG. 1 may work together to perform this process 500 to help
prevent accidents at railroad crossing 100. This example process
500 is for a single track with two motion detection zones 110
outside the boundaries of track circuit 108, as shown in FIG. 1,
although it may be applied to railroad crossings 100 with different
configurations as well. Process 500 may begin when there is no
train on track circuit 108.
[0055] At 502, one or more motion detecting cameras 112 may detect
motion. For example, motion detecting camera 112a may detect motion
within its associated motion detection zone 110a, and/or motion
detecting camera 112b may detect motion within its associated
motion detection zone 110b. It will be appreciated from FIG. 1 that
motion detecting cameras 112 may detect motion caused by a train
entering motion detection zones 110 before the train shorts
parallel rails in track circuit 108.
[0056] At 504, traffic signal control equipment 116 may receive
data indicating motion detection from at least one motion detecting
camera 112. For example, motion detecting cameras 112 may be
connected wirelessly or by wire to equipment in vehicle traffic
signal control box 114, including traffic signal control equipment
116. Traffic signal control equipment 116 may receive messages from
motion detecting cameras 112 indicating motion in associated motion
detection zones 110.
[0057] At 506, traffic signal control equipment 116 may adjust
traffic signals 104. For example, traffic signal control equipment
116 may hold traffic signals 104 at red while traffic signal
control equipment 116 is receiving messages from motion detecting
cameras 112 indicating motion in associated motion detection zones
110 to prevent traffic from moving into railroad crossing 100.
[0058] At 508, traffic signal control equipment may maintain
traffic signals 104 at red to prevent traffic from moving into
railroad crossing 100 until traffic signal control equipment 116 is
no longer receiving messages from motion detecting cameras 112
indicating motion in associated motion detection zones 110.
Additionally, traffic signal control equipment may further require
indication that track circuit 108 and/or island circuit 106 are no
longer detecting a train to switch traffic signals 104 from
red.
[0059] As mentioned above, motion detecting cameras 112 may be
non-vital. This may be possible because if no motion is detected by
motion detecting cameras 112 prior to track circuit 108 becoming
active, train detection equipment 130 will activate its preemption
output 118 in response to track circuit 108 activity. Traffic
signal control equipment 116 may detect preemption output 118 and
control traffic signals 104. This is backup logic used in case a
motion detecting camera 112 experiences a malfunction.
[0060] The above-described systems may require less setup and may
have a smaller footprint than other train detection systems. The
above-described systems may provide a relatively low cost and low
maintenance approach while also getting the railroads more familiar
with camera technology that may be used in future applications.
Pairing camera technology with event recorders and other crossing
equipment may have many future uses such as crossing light out
detection, crossing gate level detection, the monitoring of
movements within train yards, intrusion detection, automated
inspections, and more. The above-described systems may be set up
completely isolated from the railroad if desired, pushing more of
the advanced preemption burden back on the municipalities over
time. For example, the advanced preemption systems described above
may be installed and maintained by the same entities that install
and maintain municipal traffic signals in some embodiments.
[0061] While various embodiments have been described above, it
should be understood that they have been presented by way of
example and not limitation. It will be apparent to persons skilled
in the relevant art(s) that various changes in form and detail can
be made therein without departing from the spirit and scope. In
fact, after reading the above description, it will be apparent to
one skilled in the relevant art(s) how to implement alternative
embodiments. Other steps may be provided, or steps may be
eliminated, from the described flows, and other components may be
added to, or removed from, the described systems. Accordingly,
other implementations are within the scope of the following
claims.
[0062] In addition, it should be understood that any figures which
highlight the functionality and advantages are presented for
example purposes only. The disclosed methodology and system are
each sufficiently flexible and configurable such that they may be
utilized in ways other than that shown.
[0063] Although the term "at least one" may often be used in the
specification, claims and drawings, the terms "a", "an", "the",
"said", etc. also signify "at least one" or "the at least one" in
the specification, claims and drawings.
[0064] Finally, it is the applicant's intent that only claims that
include the express language "means for" or "step for" be
interpreted under 35 U.S.C. 112(f). Claims that do not expressly
include the phrase "means for" or "step for" are not to be
interpreted under 35 U.S.C. 112(f).
* * * * *