GB2498564A - Level-crossing protection system which sends a warning to an approaching train via GSM-R network - Google Patents

Abstract

A rail crossing system comprising means for detecting an obstacle on a crossing and a radio communication network for sending information to a train approaching the crossing. The radio communication network may be based on GSM or Global System for Mobile Communications - Railway (GSM-R) and the information may be sent using a protocol based on the GSM-R standard, e.g. as an Emergency Group Call message. The intrusion on the grade-crossing and the advancing train may be detected using RADAR detectors (e.g. positioned at or near the crossing).

Description

Rail Crossing Protection System A system for detecting major obstructions on un-manned rail crossings and sending information to approaching trains to warn them of the obstruction is disclosed. According to one embodiment of the invention, the Global System for Mobile Communications -Railway (GSM-R) radio network is used for sending the information directly to the trains.

In many instances where the road network intersects the rail network the crossing poinns are un-manned. In some cases they are protected by full barriers but in many cases Auto-matic Half Barriers are used and in others the crossings are passive' relying on the user to open gates and check that there are no trains approaching before traversing the rails.

At all un-manned crossings there is a risk that a vehicle may enter the crossing space when a train is approaching.

This may be, for example, because the vehicle driver has chosen to ignore the warning Wig-Vag signals (where they are provided) , or alternatively may genuinely be unable to clear the crossing space, perhaps because they have broken down.

As a secondary problem it is possible, when road junctions are in very close proximicy to a rail crossing, for vehicles to accidentally turn off che crossing onto the rails. Such vehicles can cause an obsuruction to oncoming trains even though the vehicles are not actually on the crossing (and may not be detected by conventional crossing protection sys-tems) Existing rail crossing protection systems use several means to detect potential obstructions at the crossing and then interface to the rail signaling system to stop trains that are approaching the crossings. However in many cases there are no suitabie signals in place that can be activated in time to stop an approaching train. These may be either too far away from the crossing so the train has already passed them at the point that the crossing is identified as ob- structed, or they are too close to the crossing so that ac-tivating the signal does not provide enough time to slow or stop the train.

It is known in the art to use radio network infrastructure to establish communication between transceivers at a rail crossing and trains. Examples of this are disclosed in W02007/134430 Al, US 5,86,304 or FR 2 784 342.

The object of the present invention is therefore to provide a system that allows at least a warning to be issues to an approaching train in such circumstances.

According to the invention, a system is provided comprising at least means for detecting an obstruction on a rail cross- ing and sending an information to at least one train ap- proaching the crossing, wherein the sending of the informa-tion to the train is realised using a radio communication network. This has the advantage that such information, e.g. a warning message sent to the train to notify the train driver and/or train control system of a detected obstruction on the rail crossing, is received without further delay which might be caused by involvement of other network compo-nents and/or rail signalling infrastruture.

According to one embodiment of the invention, a radio commu-nication protocol based on the GSN-R radio communication standard is used. The GSM-R standard is inter alia defined in ETSI standards EN 301 515 and the technical specification ETSI TS 102 281. According to a further embodiment of the invention, an Emergency Group Call message is used for send-ing the information.

According to another embodiment of the invention, radar de- tectors are used to detecu an obstruction!on the rail cross-ing. Such radar based detector is for example the Heimdall traffic detector of Siemens which is already used for detec- tion of road based traffic, see for example the document en-titled "Heiradall traffic detector family", available via the following link: http://www.siemens.co.uk/craffio/pool/documents/brochure/hei mdall2.pdf According to another embodiment of the invention, radar de-tectors are also used to detect trains approaching the rail crossing.

The present invention is intended to enhance the safety at a variety of different crossing types and provides an addi-tional safety feature.

Examples of the inventive concepts are further described with reference to the following figures.

FIG 1 shows an overview of an automatic half barrier sys-tern, FIG 2 the system of FG 1 with additional on-track detec-tons, FIG 3 shows an overview of a user worked crossing pro-tected by miniature warning lights, and FIG 4 shows an overview of a user worked single track crossing.

System at Automatic Half Barrier (AHB) crossings System topography: (FIG 1) . The system consists of two spe-cial radar detectors posinioned to detect vehicles or other potential obstructions on the crossing, which are able to detect both moving and stationary obstructions. Two further detectors are arranged to detect the approaching trains, so that the system can be disabled as the train passes through the crossing, to prevent unwanted warning messages being sent to the train.

A processor unit and a GSM-F( radio module are located in an equipment cabinet which might is mounted on the pole of the Wig-Wag crossing signal. Such processor may be a processor used for the so called Gemini platform of Siemens. For fur-ther information, please refer to the following link: http://www.siernens.co.uk/nraffic/pooi/doournents/brochure/gem ml.pdf The processor unit is responsible for analysing data from the detectors and also from the barrier controller and also for sending an Emergency Group Call according to the GEM-P protocol, the Emergency Group Call containing the crossing name or identifier of the crossing, should an obstruction be detected when the barriers are down.

Operational details: The system is armed' by a confirmation signal from the barrier controller indicating that the bar-rier is down' Such confirmation may be provided via a volt-free contact, where an open contact indicates barrier down. This is fault tolerant as any loss in cable integrity will automatically arm the system.

Once the system is armed, any presence detected cn the crossing which persists for greater than a configurable time, (initially set at e.g. 2 seconds) will give rise to an Emergency Group Call via The GSYI-R network. For example, a voice call message will be automatically generated by the processor unit and will contain a warning that the crossing may be obstructed, together with the crossing name to ensure that if mare than one train is within group call area in which the Emergency Group Call will be broadcasted, it is clear which train may be at risk of a potential collision with the obstruction on the crossing. For example, two cy-cles of the warning message wili be played, after which the processor unit will release the uplink of the radio cornrnuni-cation to the GSM-R communication network. The call will be automatically answered by all train based radio transceivers (aiso called cab radios) in the group call area. The cab ra- dio in the train will display the emergency call and. for ex- ample the message STOP" and the driver will hear the warn-ing announcement. The driver wiil then stop the train and acknowledge the emergency call which will remove the "STOP" message from the display of the cab radio. The driver can then attempt to speak to The signaller by pressing the PTT (Push-To-Talk) button on The handset. The signaller will then release the call.

As the train approaches the crossing, it will be detected by the approach detector which will disable the sending of any warning messages during the trains passage over the crossing and for a configurable time after it has passed the cross- ing. This time may be typically a few seconds. If the barri-ers are still down at the end of this configurable period the system will be re-armed, as it will be assumed another train is approaching. The approach detectors, specifically the above mentioned Heimdall detectors from Siemens, will be able to detect trains approaching at speeds between approxi-mately 4 and 120 KPH.

The system will be disarmed when the barrier down signal in-dicates that the barrier is no longer in the down position.

As part of the processor functionality, a time-stamped log may record the time and date of each barrier down event and each Group Call made for future reference should this be needed.

Further features Detector fault Monitoring: The system is dependent on its detectors functioning properly and these may be regularly validated using Detector Fault 4onitoring (DFM) principals.

B

For the on-crossing deteccors the detection of vehicles nor- mally traversing the crossing is used to validate the cor-rect operation of the detectors. If detector activation has not been seen for a configured time (i.e.the DFM time) then the detector will be assumed to be faulty. The HEM time set-ting must take account of times of low crossing usage (such as Holidays etc.) so it may be set to be up to 18 hours. If required, further sophistication is able to be configured to provide a Holiday Clock' feature so that DFM times could be set up more precisely to account for such special days. Fcr example, during the day the HEM time is short, e.g. 30 min-utes, whereas at night this should be longer, e.g. 2 hours, and on holidays e.g. B hours.

Similarly, the train approach detectors may be included in the DFM system and be validated by their regular activation by trains.

The actions taken on the failure of a system detector may be configured in the system and range from simply logging the fault, through to sending a activating a regular CSM-R voice message warning approaching trains that the system is not functioning properly.

Alternatively the system can send a warring to the rail net-work maintenance team who will notify the signaller, who can then notify the train driver if required. In this case the warning will be a data message rather than a voice message.

Barrier Monitoring: If volt free contacts are available tc indicate when the barriers are down and also when the TATig_ Wag signals are operational an additional level off monitor-ing is able to be provided as follows.

If the barrier down confirmation is not received within a configurable time after the wig-wag signals show red, an F-mergency Group Call message will be automatically generated by the processor and will contain a warning that the cr0ss-ing barriers may not be down, together with the crossing name. Note: If an emergency call is made all trains will automatically stop and they can then be advised to proceed at caution by the signaller.

Protection against vehicles turning onto the tracks: With the wide use of mobile satellite navigation systems in cars and trucks, the number of incidence of drivers accidentally turning cntc tracks at rail crossings located very close to road intersections, mistaking the tracks for a road turning and then becoming stuck there, has increased. This type of incident is even more prevalent at night.

By adding additional detectors at rail crossings it is pos- sible to provide a degree of protection against this eventu-ality.

The system will monitor the on-track detectors whenever the barriers are up and if a presence is observed for more than a configurable time (e.g. nominally a few seconds) a poten-tial hazard situation will be logged. See FIG 2.

To warn approaching trains of the hazard, the system will send a Emergency Group Call message to warn approaching trains that there is a vehicle on the track. The message will contain the crossing name or identifier to ensure that if more than one train is within group call area, it is clear which trains may be at risk. This message will for ex-ample typically be repeated every 30 seconds (but this may be configurable) whilst the presence continues to be de-tected.

System at Automatic Open Crossings Locally Monitored (AOCL) These will be monitored as for the AHB orossing exoept the system will be armed by the Wig-Wag active signal after a configurable delay.

System at User Worked Crossings Protected by Miniature Warn ing Lights For double tracked sections the system is similar to the AHB topography but dedicated poles are required to mount the de-tectors as there will not be Wig-Wag poles available (FIG 3) . In addition it is possible that local mains power will also not be present so a combination of solar and/or wind power source for powering the detectors, processor unit and GSM-R radio module may be required.

In this specific configuration, it would be required to gen-erate an activate' signal from the red miniature warning signal. This will involve inserting a relay in the lamp power line or to use an optical sensor to detect when the warning light is lit.

For single track sites the overall topography is able to be arranged so that all equipment is provided on the same side of the tracks, eliminating the need to cable across them (FIG 4).

Passive Crossings These may be be protected in a similar fashion to User Worked crossings. However, in these cases there is usually no indication at the crossing that a train is approaching, consequently a simple radar detector is located along the track at sufficient distance to give adequate warning of the approaching train. The distance is dependent on track speed but should allow for at least 40 seconds notice of the on-coming train.

Physical cables may be used to link the detectors to the system, but alternatively, this may also be done using wire-less equipment.

Although the foregoing description refers to GSM-R, the de-scribed invention may also be implemented in the same way using other radio communication systems or standards, for example a rail specific adaptation of communication system based on the UMTS (Universal Mobile Telecommunication Stan-dard) standard as an evolutionary step from the well-known GS4-R standard.

Claims (1)

1. <claim-text>Claims 1. Rail crossing system, comprising at least means for detecting an obstruction on a rail cross-ing, and means for sending an information to at least one train ap- proaching the crossing, wherein the sending of the informa-tion to the train is realised using a radio communication network.</claim-text> <claim-text>2. Rail crossing system according to claim 1, wherein the radio communication network is a GSM or GSM-R based net-work or an evolution of this radio communication systems.</claim-text> <claim-text>3. Rail crossing system according to claim 1 or 2, wherein a radio communication prorocol based on the GSM-R radio ccm-munication standard is used for sending the information.</claim-text> <claim-text>4. Rail crossing system according to claim 3, wherein an Emergency Group Call message is used for sending the in-formation.</claim-text> <claim-text>5. Rail crossing system according to any of the preceding claims, wherein at least one first radar detector is used to detect the ob-struction on the rail crossing.</claim-text> <claim-text>6. Rail crossing system according to any of the preceding claims, wherein at least one second radar detector is used to detect trains approaching the raii crossing.</claim-text> <claim-text>7. Rail crossing system according to claim 6, wherein the at least one second radar detector is positioned at or in proximity to the rail crossing.</claim-text>