U.S. patent application number 13/639106 was filed with the patent office on 2013-08-08 for crossing safety system.
This patent application is currently assigned to Cohda Wireless Pty. Ltd.. The applicant listed for this patent is Paul Dean Alexander, David Victor Lawrie Haley. Invention is credited to Paul Dean Alexander, David Victor Lawrie Haley.
Application Number | 20130200223 13/639106 |
Document ID | / |
Family ID | 44761917 |
Filed Date | 2013-08-08 |
United States Patent
Application |
20130200223 |
Kind Code |
A1 |
Alexander; Paul Dean ; et
al. |
August 8, 2013 |
CROSSING SAFETY SYSTEM
Abstract
A system is described that provides redundant communication at a
railway crossing. The system comprises a first communication unit
for transmitting information associated with a railway vehicle
approaching or near the railway crossing on a railway track. A
first active warning sign located at or near the railway crossing
receives and transmits information associated with the railway
crossing. The system includes an onboard equipment unit located on
a roadway vehicle approaching or near the railway crossing, the
onboard equipment unit comprising a second communication unit for
receiving information from the first communication unit and the
active warning sign; a processor for processing the received
information to determine a first threat indicator indicative of a
potential collision, and a user interface for communicating the
threat indicator to a user. The system may include sensors to
detect and communicate the presence of a train.
Inventors: |
Alexander; Paul Dean;
(Crafers, AU) ; Haley; David Victor Lawrie;
(Stepney, AU) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Alexander; Paul Dean
Haley; David Victor Lawrie |
Crafers
Stepney |
|
AU
AU |
|
|
Assignee: |
Cohda Wireless Pty. Ltd.
Kent Town
AU
|
Family ID: |
44761917 |
Appl. No.: |
13/639106 |
Filed: |
April 5, 2011 |
PCT Filed: |
April 5, 2011 |
PCT NO: |
PCT/AU11/00385 |
371 Date: |
February 15, 2013 |
Current U.S.
Class: |
246/473.1 |
Current CPC
Class: |
B61L 29/30 20130101;
B61L 23/041 20130101; B61L 29/28 20130101; B61L 29/32 20130101 |
Class at
Publication: |
246/473.1 |
International
Class: |
B61L 29/30 20060101
B61L029/30 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 5, 2010 |
AU |
2010901429 |
Claims
1. A communication system for redundant communication at a railway
crossing, the system comprising: a first communication unit for
transmitting information associated with a railway vehicle
approaching or near the railway crossing on a railway track; a
first fixed communication unit located at or near the railway
crossing for receiving and transmitting information associated with
the railway crossing; and an onboard equipment unit located on a
roadway vehicle approaching or near the railway crossing, the
onboard equipment unit comprising: a second communication unit for
receiving information from the first communication unit and the
fixed communication unit; a processor for processing the received
information to determine a first threat indicator indicative of a
potential collision, and a user interface for communicating the
threat indicator to a user.
2. The system of claim 1 wherein the first communication unit
comprises: a sensor system located at or near the railway crossing
for sensing information associated with the railway vehicle and a
second fixed communication unit adapted to transmit the information
sensed by the sensor system, wherein in use the information is
received by the first fixed communication unit and the onboard
equipment unit.
3. The system of claim 1 wherein the first communication unit is
located on the railway vehicle and transmits information about the
railway vehicle that in use is received by the first fixed
communication unit and the onboard equipment unit.
4. The system of claim 3 further comprising: a sensor system
located at or near the railway crossing for sensing information
associated with the railway vehicle; and a second fixed
communication unit adapted to transmit the information sensed by
the sensor system.
5. The system of claim 3 or 4 wherein the onboard equipment unit
communicates information about the roadway vehicle to the first
communication unit located on the railway vehicle.
6. The system of any one of claims 3-5 wherein the onboard
equipment unit communicates information about the roadway vehicle
to the first fixed communication unit.
7. The system of any one of the preceding claims wherein the
information comprises one or more of the following: a position of
the railway or roadway vehicle, a direction of the railway or
roadway vehicle, a speed of the railway or roadway vehicle.
8. The system of any one of claims 3-7 wherein the first
communication unit located on the railway vehicle comprises: a
receiver for receiving information; a railway-vehicle processor
programmed to process the received information to determine a
second threat indicator indicative of a potential collision; and a
human-to machine interface to alert a human operator if the
railway-vehicle processor has determined a second threat
indicator.
9. The system of any one of the preceding claims wherein the first
fixed communication unit comprises: a receiver for receiving
information; a railway-sign processor programmed to processing the
received information to determine whether to close the railway
crossing; and a transmitter that in use transmits a crossing-closed
indicator if the railway-sign processor determines that the
crossing should be closed.
10. The system of any one of the preceding claims wherein the
onboard equipment unit comprises a first navigation satellite
system to monitor a position of the roadway vehicle.
11. The system of any one of claims 3-13 wherein the first
communication unit comprises a second navigation satellite system
to monitor a position of the railway vehicle.
15. An active warning sign for a railway crossing, the sign
comprising: a first communication link operable to receive sensor
information from a sensor system located at or near the railway
crossing for sensing the approach or presence of a railway vehicle;
a second communication link operable to receive a crossing-close
request (CCR) from onboard equipment located on the railway
vehicle; a warning-sign processor programmed to monitor the first
and second communication links and to generate a crossing-closed
indicator (CCI) based on received sensor information and/or a
received crossing-close request; and a transmitter to transmit the
crossing-closed indicator.
16. The active warning sign of claim 15 further comprising at least
one warning light, wherein the warning-sign processor activates the
at least one warning light if the crossing is closed.
17. The active warning sign of claim 15 or 16 wherein the railway
crossing comprises a physical barrier and the warming-sign
processor initiates closure of the physical barrier if the crossing
is closed.
18. The active warning sign of any one of claims 15-17 wherein the
first communication link is a hard-wired link between the warning
sign and the sensor system.
19. An on-board communication system for redundant communication at
a railway crossing, the system comprising: an onboard equipment
unit for use by a roadway vehicle approaching or near the railway
crossing, the onboard equipment unit comprising: a communication
unit for receiving information from a plurality of sources, said
sources comprising (a) an active warning sign that transmits a
crossing-closed indication (CCI) if the crossing is closed and (b)
a railway communication unit that transmits information indicative
of the presence or approach of a railway vehicle at the railway
crossing; a processor for processing the received information to
determine a threat indicator indicative of a potential collision,
and a user interface for communicating the threat indicator to a
user.
20. The system of claim 19 wherein the communication unit transmits
roadway vehicle information indicating at least one of a position,
direction and speed of the roadway vehicle,
21. A method of operating an active warning sign for a railway
crossing, the method comprising: monitoring for sensor information
from a sensor system located at or near the railway crossing for
sensing the approach or presence of a railway vehicle; monitoring
for receipt of a crossing-close request (CCR) from on-board
equipment located on the railway vehicle; generating a
crossing-closed indicator (CCI) based on received sensor
information and/or a received crossing-close request; and
transmitting the crossing-closed indicator,
22. A method of operating an on-board communication system for a
roadway vehicle approaching or near a railway crossing, the method
comprising: monitoring for information from an active warning sign
that transmits a crossing-closed indication (CCI) if the railway
crossing is closed; monitoring for information from a railway
communication unit that transmits information indicative of the
presence or approach of a railway vehicle at the railway crossing;
processing received information to determine a threat indicator
indicative of a potential collision, and communicating the threat
indicator to a user.
Description
FIELD OF THE INVENTION
[0001] The invention relates to wireless communications systems to
improve safety at railway crossings.
BACKGROUND OF THE INVENTION
[0002] Collisions can occur at railway crossings between trains and
other vehicles such as cars or trucks. Even if booms, signposts or
lights are used, these may be seen too late by drivers resulting in
a collision. These collisions can sometimes cause fatalities.
[0003] Dedicated Short-Range Communication (DSRC) is the globally
coordinated standard for Cooperative Intelligent Transportation
Systems (ITS). DSRC combines GPS and wireless communication in a
dedicated spectrum at 5.9 GHz. Safety-of-life applications, such as
cooperative collision avoidance are the key feature of DSRC, and
the 5.9 GHz spectrum includes a communications channel dedicated to
cooperative safety applications.
[0004] Vehicles use DSRC to share information by continually
broadcasting their location, speed, direction, vehicle type and
size, and additional status information. The DSRC system also
includes a processor that uses local position information, and
information received from other vehicles, to accurately detect
potential collisions and activate driver warnings. DSRC Roadside
Equipment (RSE) allows communications between vehicles and
infrastructure, e.g. railway warning systems including active
warning signs.
[0005] It is desirable to have a communication system that improves
collision avoidance at railway crossings.
[0006] Reference to any prior art in the specification is not, and
should not be taken as an acknowledgment or any form of suggestion
that this prior art forms part of the common general knowledge in
Australia or any other jurisdiction or that this prior art could
reasonably be expected to be ascertained, understood and regarded
as relevant by a person skilled in the art.
SUMMARY OF THE INVENTION
[0007] In one aspect the invention provides a communication System
for redundant communication at a railway crossing, the system
comprising: a first communication unit for transmitting information
associated with a railway vehicle approaching or near the railway
crossing on a railway track; a first fixed communication unit
located at or near the railway crossing for receiving and
transmitting information associated with the railway crossing; and
an onboard equipment unit located on a roadway vehicle approaching
or near the railway crossing, the onboard equipment unit
comprising: a second communication unit for receiving information
from the first communication unit and the fixed Communication unit;
a processor for processing the received information to determine a
first threat indicator indicative of a potential collision, and a
user interface for communicating the threat indicator to a
user.
[0008] The first communication unit may further comprise a sensor
system located at or near the railway crossing for sensing
information associated with the railway vehicle and a second fixed
communication unit adapted to transmit the information sensed by
the sensor system, wherein in use the information is received by
the first fixed communication unit and the onboard equipment
unit.
[0009] The first communication unit may be located on the railway
vehicle and transmits information about the railway vehicle that in
use is received by the first fixed communication unit and the
onboard equipment unit.
[0010] In another aspect the invention provides an active warning
sign for a railway crossing, the sign comprising: a first
communication link operable to receive sensor information from a
sensor system located at or near the railway crossing for sensing
the approach or presence of a railway vehicle; a second
communication link operable to receive a crossing-close request
(CCR) from onboard equipment located on the railway vehicle; a
warning-sign processor programmed to monitor the first and second
communication links and to generate a crossing-closed indicator
(CCI) based on received sensor information and/or a received
crossing-close request; and a transmitter to transmit the
crossing-closed indicator.
[0011] In another aspect the invention provides an on-board
communication system for redundant communication at a railway
crossing, the system comprising: an onboard equipment unit for use
by a roadway vehicle approaching or near the railway crossing, the
onboard equipment unit comprising: a communication unit for
receiving information from a plurality of sources, said sources
comprising (a) an active warning sign that transmits a
crossing-closed indication (CCI) if the crossing is closed and (b)
a railway communication unit that transmits information indicative
of the presence or approach of a railway vehicle at the railway
crossing; a processor for processing the received information to
determine a threat indicator indicative of a potential collision,
and a user interface for communicating the threat indicator to a
user.
[0012] Further aspects of the invention will be apparent from the
following description, including methods of operating the described
system and machine-executable instructions effective to implement
the methods in the described system.
[0013] As used herein, except where the context requires otherwise,
the term "comprise" and variations of the term, such as
"comprising", "comprises" and "comprised", are not intended to
exclude further additives, components, integers or steps.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Further aspects of the present invention and further
embodiments of the aspects described in the preceding paragraphs
will become apparent from the following description, given by way
of example and with reference to the accompanying drawings.
[0015] FIG. 1A shows a DSRC communication system that may be used
in a crossing safety system.
[0016] FIG. 1B shows a flow diagram of processes run by a Threat
Detection Unit.
[0017] FIG. 2 shows a sensor-to-sign communication system:
[0018] FIG. 3 shows a schematic representation of the
sensor-to-sign communication system of FIG. 2.
[0019] FIG. 4 shows a sensor-to-vehicle communication system.
[0020] FIG. 5 shows a schematic representation of the
sensor-to-vehicle communication system of FIG. 4.
[0021] FIG. 6 shows a train-to-sign communication system.
[0022] FIG. 7 shows a schematic representation of the train-to-sign
communication system of FIG. 6.
[0023] FIG. 8 shows a train-to-vehicle communication system.
[0024] FIG. 9 shows a schematic representation of the
train-to-vehicle communication system of FIG. 8.
[0025] FIG. 10 shows a vehicle-to-train communication system in an
example in which a vehicle has stopped across the tracks.
[0026] FIG. 11 shows a schematic representation of the
vehicle-to-train communication system of FIG. 10.
[0027] FIG. 12 shows a schematic representation of a compound
communication system.
[0028] FIG. 13 shows a schematic representation of the messages
sent in a collision avoidance communication system.
[0029] FIG. 14 shows infrastructure-to-vehicle (I2V) communication
actual timing in an example based on a collision that occurred near
Kerang in Australia.
[0030] FIG. 15 shows train-to-vehicle (T2V) communication warning
onset in the example of FIG. 14.
[0031] FIG. 16 shows T2V communication warning evolution.
[0032] FIG. 17 shows an example of how a truck passes safely behind
a train with no warnings issued.
[0033] FIG. 18 shows an example of how a truck passes safely ahead
of a train with no warnings issued.
[0034] FIG. 19 shows T2V communication of a near miss with a
warning issued.
[0035] FIG. 20 shows T2V communication in an example based on an
event that occurred at Benalla in Australia.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0036] A crossing safety system is described herein that provides
immediate safety improvement through the use of active signs and
sensors with DSRC/WAVE communications and is directly extensible
when vehicles are fitted with units. WAVE refers to wireless access
in vehicular environments. An acronym list is provided at the end
of the description, When fitted with Onboard Equipment (OBE) the
vehicles will become aware of the crossing state and/or the
presence of a crossing train or other vehicle: The OBE may then
choose to alert the driver to the presence of the crossing vehicle.
As the underlying wireless technology is DSRC, the warning can be
timely and directional, avoiding unnecessary driver distraction and
inconvenience due to extended waiting times at the crossing.
[0037] 1. System Overview
[0038] A crossing safety system employed in vehicles and
infrastructure elements using wireless communication is described
herein.
[0039] One embodiment of a DSRC system 100 is shown in FIG. 1A.
Infrastructure at the crossing will transmit messages to OBEs
indicating the state of the crossing, A vehicle is fitted with OBE
101 that is used to communicate with other OBEs 102 via
vehicle-to-vehicle (V2V) communications, and RSEs 104 via
vehicle-to-infrastructure (V2I) communications. The types of
vehicles involved in a railway crossing, and which could also
include such OBE, include cars, trucks, vans, trains, buses,
motorbikes (and variants thereof), and pedal bikes. Pedestrians may
also be involved.
[0040] The OBE 101 includes a human-machine interface (HMI) 106 for
driver interaction. The HMI 106 may be an audio, visual or haptic
interface, or any combination of these, Examples of interfaces that
may be used include a touch screen, or a display screen and a
keyboard. The OBE 101 includes a processor 108 for running
applications and providing control, The processor may be a
microprocessor, DSP, FPGA or other comparable processing device.
The OBE 101 further includes a satellite navigation system such as
a GPS 110 for providing the processor 108 with position and time
data, and a DSRC radio 112 for providing wireless connectivity to
other vehicle OBEs 102 and RSE 104 via antenna 114.
[0041] Software running on the processor 108 provides a Threat
Detection Engine (TDE). The TDE receives local position information
from the GPS 110, and receives position and state information from
other vehicles, sensors and signs via the DSRC radio 112. The TDE
determines any threat and presents required driver interaction on
the HMI 106.
[0042] The TDE in the OBE will decide which warnings, if any, will
be issued to the driver. The TDE will respond (via the human
machine interface) to:
[0043] 1. Basic Safety Messages (BSMs; broadcast messages
containing position information of the host unit e.g. train or car)
sent from trains and other vehicles; and
[0044] 2. Road Side Alert messages (RSAs; broadcast messages that
transmit a signal using serial data communication, for example one
of the SAE J2540 phrases) sent from the Crossing Infrastructure.
The complete set of ITIS codes can be found in Volume Two of the
J2540 Standard.
[0045] A TDE in a train may also warn the train driver of a
potential danger such as a vehicle parked across the crossing.
[0046] Referring to the flow diagram in FIG. 1B, the TDE functions
as follows. When a new message is received 2101 by the DSRC radio
112 (shown in FIG. 1A), then the received message is queued at step
2102. The message type is checked 2103, and if the received message
is a BSM then the remote entity (the entity that the message is
received from) is pre-qualified 2104. Pre-qualification is a step
to determine whether the remote entity, which can be a train or
other vehicle, is threatening, i.e. whether there is a possibility
of a collision. The checks that are performed at this step 2104 may
be one or more of the following:
[0047] i. Is the remote entity getting closer (determined from
heading, speed of present vehicle and remote entity)?
[0048] ii. Can the distance between the remote entity and the
present vehicle be closed within a short time based on the closing
velocity and the distance between the two entities? Closing
velocity is based on the respective headings and speed. Predicted
motion can also be employed. For example motion on a circle may be
used where each entity is aware of its radius.
[0049] iii. Are the two entities very far apart?
[0050] iv. Are the entities' speeds above a threshold (both or
any)?
[0051] v. Do the trajectories of the two entities cross in the
future?
[0052] Following the pre-qualification step 2104, if the remote
entity is threatening, then the distance to the collision is
determined at step 2106. Following this, it is determined at step
2107 whether the present vehicle is able to stop at high
deceleration. If not, then a high level HMI collision warning is
issued 2108. If yes, then at step 2108 it is determined whether the
present vehicle is able to stop at low deceleration. If not, a low
level HMI crossing warning is issued 2110. If yes, no warning is
issued.
[0053] If it is determined at step 2103 that the message is not a
BSM, then at step 2111 it is determined whether the message is an
RSA containing a CCI or CCR. If so, then the likelihood of the
present vehicle entering the crossing is determined at step 2112.
This may be done as follows:
[0054] using data from the GPS 2114 to determine whether the
present vehicle is closing on the crossing, i.e. whether the
distance to the crossing is reduced over time; or
[0055] using map matching to a map database 2115 to determine the
future path of the vehicle.
[0056] At step 2118 the following decision is made: if the
likelihood of entering the crossing is high, then an HMI crossing
warning is played 2122; if the likelihood is low, then the HMI
crossing warning is disabled 2120.
[0057] The TDE is also used to transmit a BSM 2130 based on the
local position handler 2116, The message is transmitted 2132 using
the DSRC radio 112.
[0058] A crossing safety system consists of three main equipment
types: vehicle, sensor and sign. The train and the vehicle are very
similar and may be accommodated by the same equipment type in a
different mode. The sign 104 also includes a processor and a DSRC
radio system in communication with the processor.
[0059] Table 1 shows what equipment transmits what messages and
what equipment listens to those messages. Referring to Table 1,
mobile equipment refers to equipment on trains and other vehicles.
Fixed equipment or units refer to roadside sensors and signs. The
functionality executed upon receipt is described in the summary of
the connectivity table below.
TABLE-US-00001 TABLE 1 Unit Connectivity Table Tx Rx Equipment BSM
RSA BSM RSA Vehicle OBE Train OBE Sensor Sign
[0060] The summary of this connectivity table is as follows:
[0061] 1.1 Mobile Equipment Transmit BSMs
[0062] Mobile onboard equipment (in trains and vehicles) announce
the train or vehicle's dynamic position to all via broadcast of
BSMs, e.g. periodically with a-rate of a few times per second.
Mobile equipment may have a positioning service.
[0063] 1.2 Fixed Equipment Transmit RSAs
[0064] Inbound sensors may announce the presence of the train at
the sensor location by transmission of a Crossing Close Request
message (CCR). The inbound sensor continues to transmit this
message, e.g. periodically with a rate of a few times per second
while the train is present.
[0065] Signs announce the crossing state by transmission of a
Crossing Closed message or a Crossing Open message. Transmission
may be periodic, e.g. with rate of a few times per second.
[0066] In the case of a track that supports bi-directional traffic
it is preferred but not required that the sensor should be capable
of sensing direction of travel. RSAs are transmitted upon the
occurrence of asynchronous events. The fixed units may be
programmed with their position and the co-ordinates of the crossing
at installation. Otherwise they may determine their position from
other wireless equipment in the vicinity of the crossing.
[0067] 1.3 All Units Listen for BSMs
[0068] Mobile equipment determines if a collision could occur.
Fixed equipment can still sense the train if the sensing element
fails.
[0069] Signs can signal to trains that a vehicle may enter or is
stationary in the crossing. This is achieved by the sign first
determining the current and likely position of the vehicle and then
if necessary transmitting a message that the train can use to
determine the state of the vehicle relative to the crossing.
[0070] 1.4 Mobile Units and Signs Listen for RSAs
[0071] Mobile equipment determines that the crossing is closed to
vehicles. Receipt of a Crossing Closed Indicate message (CCI) tells
the mobile equipment that the crossing is closed. Receipt of a
(Crossing Closed Request) CCR tells the Mobile equipment that the
crossing is closed.
[0072] Signs are told by the sensor via a CCR that the crossing
should be closed. Signs then close the intersection by broadcast of
CCI. This broadcast continues e.g. at a rate of several messages
per second until the crossing is opened.
[0073] Other messages may be used to convey the information
described. In the preferred embodiment DSRC is used. One benefit
for DSRC is that it has a standard way of encapsulating positional
information.
[0074] All units in the system can keep a health check on the other
units. Units may periodically transmit a special message indicating
that they are functional. This message may or may not contain
status information, and may identify the unit transmitting the
message. if this message is not heard by all units then the
crossing may enter a fail safe mode, e.g. an active sign may switch
into active mode. Normal operational messages (due to a crossing
event) may be used instead of, Or in addition to, periodic messages
to monitor system health in the same way.
[0075] For simplicity one approach direction is described herein,
but in general there may be two or more signs and an additional
inbound sensor on the other approach direction.
[0076] 2. Implementation Scenarios
[0077] The equipment of the system as described above can be
implemented in a number of ways. Five example scenarios are
described below.
[0078] 2.1 Sensor-to-Sign: Train Approaching Warning
[0079] Referring to FIG. 2, in the Sensor-to-Sign scenario 200,
DSRC RSE is installed at inbound 202 and outbound 204 rail sensors
and active warning signs 206. Approaching trains 208, and
potentially other rolling stock, trigger the inbound sensor 202. An
active warning sign 206 is then started to attract the attention of
approaching motorists, e.g. through visual and/or auditory warning.
An outbound sensor 204 detects departure of the train 208 and
deactivates the sign 206.
[0080] Inbound 202 and outbound 204 sensors are installed in each
direction of approach by rail (for clarity, only a single direction
is shown in FIG. 2). Similarly, an active warning sign 206 is
installed in each direction of approach by road.
[0081] A system schematic of the technology solution for this
scenario 200 is shown in FIG. 3. Both sensors 202, 204 are
connected to DSRC RSE. When the inbound sensor 202 is triggered, it
broadcasts a DSRC standard Roadside Alert Message 302 announcing
the arrival of the train 208. DSRC RSE at the sign 206 receives the
broadcast and activates the sign, and it also begins to broadcast a
Roadside Alert Message 302 announcing the presence of the train
208. The outbound sensor 204 (which may be co-located with the sign
206) detects the departure of the train 208. Once the train has
departed, the sign 206 is deactivated and the RSE broadcasts a
standard Roadside Alert Message announcing that the crossing is no
longer occupied.
[0082] The inbound sensor 202 may also provide information
pertaining to the speed and direction of the train 208. The speed
may be measured in a variety of ways known to those skilled in the
art including pairs of sensors such as loops, Doppler RADAR, etc.
This information may be used to adjust the amount of time that the
sign 206 is active, and minimise unnecessary delays.
[0083] 2.2 Sensor-to-Vehicle: Train Approaching Warning
[0084] Referring to FIG. 4, in the Sensor-to-Vehicle scenario 400
approaching trains 208, and potentially other rolling stock, again
trigger an active sign 206, as described in Section 2.1. DSRC OBE
is fitted to vehicles 402 approaching the railway crossing on the
road 404. Messages broadcast from the infrastructure 202, 204, 206
are also received by approaching vehicles 402, and trigger an
in-vehicle warning.
[0085] Note that in the case where the crossing has conventional
equipment already fitted, new equipment may be fitted to the
crossing to transmit messages. This new retrofitted equipment may
be sensitive to the state of the crossing as determined by the
pre-existing equipment.
[0086] A system schematic of the technology solution for this
scenario is shown in FIG. 5. The infrastructure system broadcasts
Roadside Alert Messages as described in Section 2.1. These messages
are also received by an approaching vehicle 402. DSRC OBE in the
vehicle processes the message and determines if, and how, the
driver should be warned. The nature of the warnings may be based
upon the position, speed, acceleration and heading of the
vehicle.
[0087] 2.3 Train-to-Sign: Train Approaching Warning
[0088] Referring to FIG. 6, in the Train-to-Sign scenario 600 DSRC
OBE is installed in locomotives/trains 208 and RSE 602 is installed
in active warning signs 206. Trains 208 broadcast standard DSRC
messages that are received by the RSE 602 at the sign 206. The
active warning sign is then started to attract the attention of
approaching motorists, e.g. through visual and/or auditory warning.
The sign 206 is deactivated once the train 208 has departed the
crossing.
[0089] A system schematic of the technology solution for this
scenario 600 is shown in FIG. 7. The locomotive 208 broadcasts DSRC
standard Basic Safety Messages 702. These messages contain the
position, speed, acceleration, heading, size and type of the
locomotive. The DSRC RSE 602 at the sign 206 receives each
broadcast, processes the message and determines when to activate
and deactivate the sign, based upon the speed. direction and
heading of the train.
[0090] 2.4 Train-to-Vehicle: Train Approaching Warning
[0091] Referring to FIG. 8, in the Train-to-Vehicle scenario 800
DSRC OBE is installed in locomotives 208 and vehicles 402. Trains
208 broadcast standard DSRC messages that are received by vehicles
402. An in-vehicle warning is triggered if the potential for
collision is detected.
[0092] A system schematic of the technology solution for this
scenario 800 is shown in FIG. 9. The locomotive 208 broadcasts DSRC
standard Basic Safety Messages 702. These messages contain the
position, speed, acceleration, heading, size and type of the
locomotive. The DSRC OBE in the vehicle 402 receives each
broadcast, processes the message and determines if and how the
driver should be warned. Warnings may be based upon the status of
the train and the speed, direction and heading of the vehicle.
[0093] 2.5 Vehicle-to-Train: Vehicle Stopped Across Track
Warning
[0094] Referring to FIG. 10, in the Vehicle-to-Train case scenario
DSRC. OBE is installed in locomotives 208 and vehicles 1002.
Vehicles broadcast standard DSRC messages that are received by
approaching trains 208. If a vehicle 1002 is stopped across the
rail line and the potential for collision is detected then an
in-train warning is triggered.
[0095] A system schematic of the technology solution for this
scenario is shown in FIG. 11. The vehicle broadcasts DSRC standard
Basic Safety Messages 702. These messages indicate that the vehicle
1002 is stopped, and also contain the position, size and type of
the vehicle, The DSRC OBE in the locomotive 208 receives each
broadcast, processes the message, and determines if any part of the
vehicle 1002 is obscuring the. path of the train 208. If the
potential for collision is detected then an audible in-train
warning is issued.
[0096] 3. Complete System Including Redundancy
[0097] As described in more detail below, the system described
herein includes features that provide redundancy improving the
reliability of the overall system. More specifically, redundancy is
introduced when two or more of the scenarios as described above are
implemented simultaneously.
[0098] Referring to FIG. 12, a communication system 1200 is shown
that includes the communication equipment as described above in the
five scenarios. Dashed connections shown offer redundancy in the
system and although the receiver is not the direct target of the
message the receiver can increase its confidence that the system is
operational through reception and in some cases improve safety even
further. For example, the sensor-to-vehicle RSA link allows the
approaching car 402 to understand that the crossing is closed even
if a message from the sign 206 has not been received.
[0099] A preferred embodiment using J2735 BSMs and RSAs is shown in
FIG. 13. Standard compliant SAE J2735 and SAE J2540 messages are
employed. SAE J2735 is used for over the air communications. OBEs
(on any moving vehicle) transmit and receive J2735 BSMs.
[0100] A sign upon receipt of a CCR or BSM from a train closes the
intersection via transmission of a CCI. This message may be heard
by all OBEs (including trains). If an approaching vehicle hears a
CCI it knows the crossing ahead is closed (CCIs contain the
position of the crossing). [0101] If the approaching vehicle is a
train it now has confidence that the crossing is closed. [0102] If
the approaching vehicle is a car then the driver may be alerted to
the presence of a closed crossing ahead. Also the OBE may assess
the dynamics of the vehicle and further advise the driver to stop
more rapidly or even activate brakes autonomously, or increase
brake pressure beyond that applied by the driver.
[0103] Trains can cause trackside equipment to send a Sensor Active
message to the sensor element equipment. A sensor clement, upon
receipt of a Sensor Active message or a BSM from an approaching
train broadcasts a CCR. The train, other approaching vehicles and
the signs at the crossing can hear this message. [0104] It is
valuable to the train as it now has confirmation that the crossing
has been requested to close. [0105] It is valuable to an
approaching vehicle as it is an early indication that the crossing
it about to be closed (like an orange traffic light). [0106] It is
valuable to the signs as they can now signal that the crossing is
closed, e.g. by activation of boom gates, warning lights and
transmission of CCI RSAs.
[0107] The sensor may receive a CCI. This would allow system
integrity checking as it makes the CCR issued by the sensor now
subject to closed loop verification. The CCR and CCI contain the
coordinates of the crossing.
[0108] In general equipment is able to improve system performance
and reliability by receiving and processing every kind of
transmitted message.
4. EXAMPLES
[0109] Two fatal collisions between trucks and trains are
considered as examples below in order to demonstrate the
effectiveness of the proposed system. Two specific features of the
system are demonstrated:
[0110] 1. In the conditions leading up to the collisions the system
would have provided significant warning times; and
[0111] 2. If the timing of the events were different, resulting in
a safe scenario, then false alarms would not result.
[0112] The latter is demonstrated by advancing or retarding the
truck while keeping the train timing fixed.
[0113] The timing and position of the train and truck are replayed
into a processing unit identical to that inside an OBE. In the
field the OBE determines its own position from its local GPS
service and obtains the position of remote vehicles or trains from
receipt of DSRC messages over the air.
[0114] The warning trigger points generated in the examples below
are identical to those that would be experienced in the field.
[0115] The two scenarios analysed are "Kerang" and "Benalla":
[0116] Just North of Kerang, Victoria in June 2007 a truck crashed
into the side of a commuter train resulting in 11 fatalities. The
warning devices at the crossing were active with warning lights
operating for 25.4 seconds prior to the collision. The truck was
travelling North at about 100 km/hr and started to decelerate too
late, at about 50 m out from the crossing. The train was travelling
at 91 km/hr in a South-Easterly direction, The truck impacted the
train about 50m from the front of the train.
[0117] On Oct. 22, 2002 a B-Double truck turned across the path of
a steam power locomotive in Benalla, Victoria. The train hit midway
between the two trailers of the B-Double. Three fatalities occurred
on the locomotive. The truck and train had been travelling South
parallel to each other for sometime before the truck turned left
across the path of the train on a passive level crossing.
[0118] In the results presented, Google Earth.TM. is used as a
replay engine. It works by showing several snapshots of the train
and truck with a time-window slider. The various features shown in
FIGS. 14-20 are indicated in Table 2.
TABLE-US-00002 TABLE 2 Re-Enactment Key Item Messaging Description
Grey Lines -- Train (1502) and truck (1504) location in space
(1502, 1504) and time, length of line is length of vehicle T2V A
threatening train (Cautionary Collision Warning announced in
vehicle) (1402, 1508) T2V A threatening train (Imminent Collision
Warning announced in vehicle) (1404, 1510, 1602) -- Lateral G force
indication (1406, 1604) -- Heading of vehicle (1506, 1512) Train
Sign I2V Adjacent vehicle has received a Train Crossing (1408)
alert and conventional deceleration will be sufficient. Exclamation
I2V Adjacent Vehicle has received a Train Crossing Sign (1410)
alert and severe deceleration is required.
[0119] 4.1 Sensor-to-Vehicle: Train Approaching Warning
[0120] The Infrastructure to Vehicle implementation is first
considered that applies when either new infrastructure is deployed
at a level crossing, or system elements are retrofitted to an
existing active crossing and the train does not have an OBE.
[0121] In I2V the presence of the train is determined by sensors at
inbound and island locations. In this context there are virtual
boom gates and therefore the in-vehicle warnings tend to occur
earlier and last longer than the case where the train is
transmitting directly to the vehicle.
[0122] In Table 3 the various timing offsets and the warnings (if
any) that are induced are shown.
[0123] The vehicle must be much further offset from the crossing in
order to avoid all messages. This is because the system is behaving
like a virtual boom gate, using track-side sensors only. The Train
Crossing Ahead message will last for more than 25 seconds in most
cases.
TABLE-US-00003 TABLE 3 I2V Warning Times at Kerang Truck Severe
Warning Warning Retardation (m) Range (m) Cautionary Collision
Warning (CCW) -400 Safe Imminent Collision Warning (ICW) -200 250
Actual Incident -50 250
[0124] In FIG. 14 the warnings issued to the driver by the
infrastructure elements of the proposed system are shown. The
driver is made aware that a train is approaching the crossing
several hundred metres out from the crossing. The driver then
receives a further warning when his speed has not decreased
sufficiently to stop easily prior to the crossing.
[0125] 4.2 Train-to-Vehicle: Train Approaching Warning
[0126] In the Train to Vehicle case the train is equipped with an
OBE and infrastructure is required at the crossing. Table 4 shows
the various timing offsets and the warnings (if any) that are
induced. The truck retardation value is the distance from the
crossing of the truck when the front of the train arrives at the
crossing. Negative values mean that the train passes through the
crossing first.
TABLE-US-00004 TABLE 4 T2V Warning Times at Kerang Truck Warning
Retardation (m) Range (m) No warnings (pass behind) -200 Safe CCW
only -150 170 CCW then ICW -120 170 Actual Incident -50 180 CCW
(pass ahead) +120 160 No warnings (pass ahead) +220 Safe
[0127] FIG. 15 shows that in the Kerang incident the truck driver
would have received a warning in his cabin with 170 m distance
remaining to the crossing. This is regarded as enough distance for
reaction time and stopping distance.
[0128] FIG. 16 shows the system evolution at the point of
collision. The driver was in receipt of Cautionary Collision
Warnings then Imminent Collision warnings. The Imminent Collision
Warnings occurred when the driver needed to decelerate at the
performance limits of the truck.
[0129] False alarm suppression is important. The drivers must trust
the system and not be unnecessarily alarmed by the system. FIG. 17
and FIG. 18 show that no alarms are issued if the truck arrives
later and earlier to the crossing respectively.
[0130] FIG. 19 shows that a Cautionary Collision Warning was issued
to the driver if the truck was a little later to the crossing but
still too close to pass safely behind the train.
[0131] A particularly difficult scenario is that of Benalla. In
this case the train and truck are travelling parallel to each other
with a separation of about 25 m. Ahead there is a side road that
crosses the track. Only in the last few seconds would the train
driver be aware that the truck was about to proceed across the
track. The scenario is shown in FIG. 20. The proposed system raises
an alarm as the truck driver turns the vehicle into the bend
crossing the track. With a few seconds warning the driver could
stop the truck as speeds are quite low on this corner.
[0132] The two examples described above show that the system
described herein provides improved communication for collision
prevention.
[0133] It will be understood that the invention disclosed and
defined in this specification extends to all alternative
combinations of two or more of the individual features mentioned or
evident from the text or drawings. All of these different
combinations constitute various alternative aspects of the
invention.
ACRONYMS
[0134] BSM Basic safety message [0135] CCI Crossing Closed Indicate
message [0136] CCR Crossing Close Request message [0137] DSRC
Dedicated Short-Range Communication [0138] GPS Global Positioning
System [0139] ITS Intelligent Transportation Systems [0140] OBE
Onboard Equipment [0141] RSA Road Side Alert message [0142] RSE
Roadside Equipment [0143] TDE Threat Detection Engine [0144] V2I
vehicle-to-infrastructure [0145] V2V vehicle-to-vehicle [0146] WAVE
wireless access in vehicular environments
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