Note: Descriptions are shown in the official language in which they were submitted.
CA 02528568 2005-11-29
1 RAILROAD CROSSING WARNING SYSTEM
2
3 Field of the Invention
4 This invention relates to highway/railroad crossing warning systems, and
particularly to remote sensing of train traffic approaching such crossings.
6
7 Background of the Invention
8 Railroad crossings have long been dangerous for motorists because
9 inattention, failure to see approaching trains, or failure to correctly
judge the speed
of approaching trains can lead to catastrophic accidents and loss of life.
Some
11 studies have shown that the cause of two-thirds of the rail associated
deaths in the
12 United States are highway/railway crossing accidents. These studies provide
13 evidence that thousands of people die in crossing accidents every year,
with
14 approximately fifty percent of the crossing accidents resulting in death.
Many
highway/railroad crossings still have only passive warning signs, but
increasing
16 numbers today have active protection and include active warning devices
located
17 an extended distance from the crossing to provide adequate warning.
18 Conventional warning systems typically use an electric connection across
the
19 rails of an electrically isolated section of track. A detector is wired
across the tracks
so that when the train enters the isolated section, the tracks form a closed
circuit
21 and the detector receives a signal to indicate the presence of a train. A
controller
22 connected to the detector by long, in-ground wires, senses the short-
circuit as the
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CA 02528568 2005-11-29
1 presence of a train and activates the signal devices. These hard-wired
connections
2 are subject to many faults and, like any electrical connections, are subject
to being
3 shorted out by water, ice, corrosion or other problems.
4
Objects of the Invention
6 The objects of the present invention are: to provide a highway/railroad
7 crossing detection and warning system which is capable of being used at
extended
8 distances from the crossing to provide warning of trains; to provide such a
detection
9 and warning system which does not require hard-wiring and buried underground
cables, which can lead to faults or erroneous signals; to provide such a
crossing
11 and warning system which provides long distance warning of the approach of
trains;
12 and to provide such a crossing and warning system which is effective in use
and not
13 readiiy subject to electrical shorts and other malfunctions. Other objects
and
14 advantages of the invention will become apparent from the following
disclosure.
16 Summary of the Invention
17 A highway/railroad crossing detection and warning system uses a Doppler
18 radar transmitter and receiving warning system arrayed around a crossing
site to
19 detect movement of a train approaching the crossing. The radar warning
system
uses two sets of first and second transmitter/receiver units respectively
positioned
21 adjacent the railroad track and located an extended distance from the
crossing.
22 One set is positioned on the track direction side of the crossing, and the
other set
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CA 02528568 2005-11-29
I on the other track direction side of the crossing. The first
transmitter/receiver unit
2 of each set is directed away from the crossing and the second
transmitter/receiver
3 unit of each set is directed toward the crossing. The radar warning system
provides
4 long distance detection of moving trains. For detection of stationary or
near
stationary trains at the crossing, a presence detection system is situated at
the
6 crossing site and comprises presence detector units respectively positioned
7 adjacent the railroad track and located a close distance from the crossing.
Warning
8 signal devices at the crossing are positioned for providing aural and visual
warning
9 to motorists and work crews. A wireless communication device transmits and
receives signals between the radar waming system and the presence detection
11 warning system to the warning signal devices to control their actuation.
The system
12 is powered by solar panel arrays and storage batteries so as to avoid
running utility
13 lines to the crossing.
14
Brief Description of the Drawings
16 Fig. 1 is a plan view of the general layout of a highway/railroad crossing
17 system of the present invention.
18 Fig. 2 is a diagrammatic view of a motion detector system on a right track
19 side of the crossing.
Fig 3 is a diagrammatic view of a motion detection system on a left track side
21 of the crossing.
22 Fig. 4 is a diagrammatic view of a presence detector system on a right
track
23 side of the crossing.
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CA 02528568 2005-11-29
1 Fig 5 is a diagrammatic view of a presence detector system on a left track
2 side of the crossing.
3
4 Description of the Preferred Embodiment
In general, the highway/railroad crossing warning system consists of two
6 complete sets of warning signals such as comprising bell 17,28 and beacon
24, 35,
7 presence detectors 21, 32, and motion detectors 3, 5 and 11,13. Each set of
8 warning signals, presence detectors, and motion detectors with associated
power
9 and control equipment, is arrayed on a side, such as a left direction track
side or
right direction track side of a highway/railroad crossing. Each set is
preferably self-
11 powered, such as by a solar electrical powered system with a battery
storage
12 device. Each side also contains its own computer and transmitters relaying
13 information to the warning signals when the movement or presence of train
is
14 detected along the track. Although the disclosed system can use regular
utility
power, solar power is preferred for many installations that are remote from
utility
16 lines.
17 The warning signals provide warning signals to motorists or work crews on
18 the roadway approaching the intersection of the railroad track with the
roadway or,
19 in the case of work crews, who are working in the immediate area of the
tracks. The
warning signals are preferably both aural, such as a bell 17, 28 or siren, and
visual,
21 such as a flashing beacon 24, 35. Warning signals may also include an arm
which
22 is activated to swing downwardly and across the traffic lane.
23
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1 In the preferred embodiment, there are four separate solar power systems
2 powering the warning system. Each consists of a battery cabinet containing
storage
3 batteries 39,46,53,60 and mounting solar panel arrays 1,9,19,30. The solar
panel
4 arrays may vary in wattage from 40 to 70 watts and the number and size of
the
panels is determined by the geographical location of motion detector units 3,
5 and
6 11,13, which may vary in power requirements. The solar panels convert
sunlight to
7 electrical energy, which is then used to charge the storage batteries
located in a
8 battery cabinet. A solar controller, such as a Prostar 15, controls the
charging and
9 discharging of the batteries. A charging algorithm is designed into the
solar
controller to prevent overcharging of the batteries and will detach the load
if the
11 battery voltage reaches 11.4 volts DC. The safeguard protects the battery
from
12 damage caused by overcharging and/or over-discharging.
13 The detection system consists of presence detectors 21, 32 and motion
14 detectors 3, 5 and 11,13 arrayed so as to detect the presence and/or
movement of
trains on the track. The presence detector 21, 32 is preferably a MS Sedco
TC3O,
16 or equivalent which provides an ultrasonic detection at 49.75 Khz in a
conical
17 projection pattern. The presence detector 21, 32 senses the presence of
rail traffic
18 in the intersection of the track with the highway and causes the warning
signals to
19 continue emitting warning signals from activation by motion detectors or to
activate
upon detection of the presence of rail traffic. The presence detector 21, 32
outputs
21 a signal which is applied to a logic circuit and to a radio transmitter,
such as a linear
22 radio XT-1 H. The logic circuit sends a pulse to a latching circuit. After
sending the
23 signal to the latching circuit, the logic circuit locks out the signal from
the presence
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1 detector for a period of time, such as ten seconds. After the period is
expired, the
2 logic detector checks for the presence of an output from the presence
detector and
3 if present, sends a pulse to the latching circuit. If no signal is present
at the output
4 of the presence detector, no pulse is sent to the latching circuit.
Concurrently, the
radio transmitter transmits a signal to a radio receiver in the second warning
signal
6 system, which is usually located on the opposite side of the track on the
railroad
7 crossing and is so shown in Fig. 1.
8 A radio receiver performs a similar function to the presence detector, but
9 receives its input from a transmitter in the motion detector system 3, 5 and
11, 13.
As long as the motion detector is detecting rail traffic motion in the
direction of the
11 crossing, the radio receiver in the flashing beacon system will receive a
transmitter
12 signal from the transmitter. The radio receiver outputs a pulse to the
latching circuit
13 The latching circuit processes the pulse from either the radio receiver
orfrom
14 the presence detector and outputs a signal to the warning signal system.
The
latching circuit latches this signal in the on position so that the beacons
flash in an
16 alternating or wig-wag pattern. The output will continue to be applied to
the flasher
17 until the timer times out and disconnects the power to the latching
circuit. The timer
18 is set to disconnect power to the latching circuit after a period of time,
such as
19 twenty seconds. To allow rail traffic sufficient time to pass safely
through the
intersection, each new signal received from eitherthe radio receiverfrom the
motion
21 detector via the radio transmitter, or from the presence detector, causes
the timer
22 to reset to, for example, twenty seconds. Thus, the flasher will continue
to cause
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CA 02528568 2005-11-29
1 the beacons to flash until twenty seconds have elapsed after the last
detection of
2 rail traffic presence or motion.
3 The presence detectors 21 and 32 are located in the immediate areas of the
4 highway/railroad crossing. The motion detectors are located a substantial
distance
away from the crossing, such as 1/4 mile and may be located any distance which
6 is in line of sight range of the receiver equipment located at the crossing.
As a
7 system provides a presence detector on each side of the crossing, it also
provides
8 a motion detector on each side of the crossing.
9 The motion detector, being remotely positioned from the crossing, is part of
a system that consists of a solar panel, mounting rack, battery cabinet, back
panel
11 with solar controller, radio transmitter, motion detector, detection logic
circuit,
12 battery, aluminum pole assembly with break away base and associated wiring.
13 A motion detector, such as a MS Sedco 268, senses the motion of rail
traffic
14 coming toward or away from the motion detector. The motion detector is
preferably
a Doppler radar transmitter/receiver unit. The motion detector receiver unit
16 transmits a signal via wiring to a logic circuit which then sends a pulse
to a
17 transmitter located with the motion detection system and remotely
positioned from
18 the crossing. The transmitter may be a linear radio XT-1 H and the
transmitter
19 transmits a coded signal to a receiver located in the warning signal unit.
As long as
motion is present, either toward or away from the remotely positioned motion
21 detector 3, 5 and 11, 13 the motion detector system transmits a signal.
Since the
22 transmitter must be pulsed to transmit, the logic circuit locks out the
output of the
23 motion detector for five seconds. After five seconds, the logic detector
polls the
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CA 02528568 2005-11-29
1 motion detector for the presence of a signal. If a signal is present, it
again pulses
2 the transmitter to transmit a signal to the receiver located at the warning
signal unit.
3 If no signal is present, no pulse is sent to the transmitter.
4 The remotely positioned solar assembly is substantially identical to the
solar
assembly located at the crossing. The entire power system, with the exception
of
6 solar panels, is located in the battery cabinet. One or more solar panels
are
7 mounted on the same pole as the battery cabinet and may vary in wattage from
40
8 to 70 watts. The number and size of the panels is determined by the sunlight
9 available at the various latitudes.
In operation, when moving rail traffic comes into view of the motion detector
11 3 remotely located from the crossing, such as area 67, the motion detector
3 is
12 programmed to activate the warning system when the rail traffic's movement
is
13 toward the protected crossing by continuously sending an electronic signal
to a
14 control panel 41, Fig 2., through a hard wire 4. The control panel 41
electronically
signals the radio transmitter 43 through wire 45. The radio transmitter 43
16 broadcasts a signal to radio receivers 56 and 63, Figs. 4 and 5. The radio
receivers
17 56 and 63 electronically signal control panels 55 and 62 through wires 58
and 65.
18 Control panels 55 and 62 activate the flashing beacons 24 and 35 through
wires 25
19 and 36 and bells 17 and 28 through wires 18 and 29.
Referring again to Fig. 1, when moving rail traffic occupies the detection
area
21 68, that is, moving away from the position of the motion detector 5, the
other
22 directional transmitter/receiver unit therein directed toward the area 68
is
23 programmed to activate the highway/railroad crossing system only when the
rail
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1 traffic's movement is toward the protected crossing by continuously sending
an
2 electronic signal to control panel 41 through wire 6. Control panel 41
electronically
3 signals a radio transmitter 43 through wire 45. The radio transmitter 43
broadcasts
4 a signal to radio receivers 56 and 63. Radio receivers 56 and 63
electronically
signal control panels 55 and 62 through wires 58 and 65. The control panels 55
6 and 62 activate flashing beacons 24 and 35 through wires 25 and 36 and bells
17
7 and 28 through wires 18 and 29.
8 Turning to the other side of the crossing, when moving rail traffic occupies
9 the detection area 70, as it would when approaching the motion detector 11
on that
side, the motion detector is programmed to activate the highway/railroad
crossing
11 system only when the rail traffic's movement is toward the protected
crossing by
12 continuously sending an electronic signal to the control panel 48 through
wire 12.
13 The control panel 48 electronically signals a radio transmitter 50 through
wire 52.
14 A radio transmitter 50 broadcasts a signal to radio receivers 56 and 63.
The radio
receivers 56 and 63 electronically signal control panels 55 and 62 through
wires 58
16 and 65. The control panels 55 and 62 activate flashing beacons 24 and 35
through
17 wires 25 and 36 and bells 17 and 28 through wires 18 and 29. When moving
rail
18 traffic occupies the detection area 69, that is away from the location of
the motion
19 detector 13, the motion detector 13 is programmed to activate the
highway/railroad
crossing system only when rail traffic's movement is toward the protected
crossing
21 by continuously sending an electronic signal to control panel 48 through
wire 14.
22 Control panel 48 electronically signals radio transmitter 50 through a wire
52. The
23 radio transmitter 50 broadcasts a signal to radio receivers 56 and 63.
Radio
CA 02528568 2005-11-29
I receivers 56 and 63 electronically signal control panels 55 and 62 through
wires 58
2 and 65. Control panels 55 and 62 activate flashing beacons 24 and 35 through
3 wires 25 and 36 and bells 17 and 28 through wires 18 and 29.
4 The presence detectors have a close-in range. Referring to presence
detection area 71, on the right side of the crossing, Fig. 1, the presence
detector 21,
6 Fig. 4, electronically signals the control panel 55 through a wire 22.
Control panel
7 55 electronically signals radio transmitter 57 through wire 59. Radio
transmitter 57
8 broadcasts a signal to radio receiver 63. Radio receiver 63 electronically
signals
9 control panel 62 through wire 65. Control panel 55 maintains the activation
of
flashing beacon 24 through wire 25 and activation of bell 17 through wire 18
until
11 the signal from the presence detector 21 ceases. Control panel 62 maintains
the
12 activation of a flashing beacon 35 through wire 36 and the activation of
bell 28
13 through wire 29 until the signal broadcast from the radio transmitter 57
ceases.
14 When the rail traffic occupies the close-in presence detector area 72, the
presence detector 32 electronically signals control panel 62 through wire 33.
16 Control panel 62 electronically signals radio transmitter 64 through wire
66. Radio
17 transmitter 64 broadcasts a signal to radio receiver 56. Radio receiver 56
18 electronically signals control panel 55 through wire 58. Control panel 62
maintains
19 the activation of flashing beacon 35 through wire 36 and activation of bell
28
through wire 29 until the signal from the presence detector 32 ceases. The
control
21 panel 55 maintains the activation of the flashing beacon 24 through the
wire 25 and
22 the activation of bell 17 through wire 18 until the signal broadcast from
radio
23 transmitter 64 ceases.
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1 The invention as disclosed here may be practiced in various forms and the
2 invention is not to be limited to the specific embodiment disclosed herein,
except
3 insofar as set forth in the following claims.
12
