GB2560581A

GB2560581A - Train integrity determination

Info

Publication number: GB2560581A
Application number: GB1704302.7A
Authority: GB
Inventors: Saracino Giuseppe
Original assignee: Hitachi Rail Europe Ltd
Current assignee: Hitachi Rail Ltd
Priority date: 2017-03-17
Filing date: 2017-03-17
Publication date: 2018-09-19
Anticipated expiration: 2037-03-17
Also published as: GB2560581B; GB201704302D0

Abstract

An electrical bus 5 extends from a control unit 1 and, in use, runs the length of the train between the front and rear vehicles (2a,b). An RFID tag (3a,b) is mounted on each of the vehicles and is operatively connected to the bus so that each tag may communicate with the control unit. The control unit determines the integrity of the train by interrogating the tags, which each encode a unique identifier to identify the vehicle to which it is mounted. This determination may be done repeatedly. The connection 9 of the bus between vehicles may be integrated with mechanical couplings 10 of the vehicles so that the bus is electrically terminated upon decoupling of the vehicles. The tags may contain read-only or rewritable data, and may be encased by hermetically sealed enclosures. A second bus and tag system may be used concurrently (Fig. 1) to provide redundancy.

Description

(54) Title of the Invention: Train integrity determination Abstract Title: Train integrity determination using RFID (57) An electrical bus 5 extends from a control unit 1 and, in use, runs the length of the train between the front and rear vehicles (2a,b). An RFID tag (3a,b) is mounted on each of the vehicles and is operatively connected to the bus so that each tag may communicate with the control unit. The control unit determines the integrity of the train by interrogating the tags, which each encode a unique identifier to identify the vehicle to which it is mounted. This determination may be done repeatedly. The connection 9 of the bus between vehicles may be integrated with mechanical couplings 10 of the vehicles so that the bus is electrically terminated upon decoupling of the vehicles. The tags may contain read-only or rewritable data, and may be encased by hermetically sealed enclosures. A second bus and tag system may be used concurrently (Fig. 1) to provide redundancy.

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Intellectual

Property

Office

Application No. GB1704302.7

RTM

Date :16 August 2017

The following terms are registered trade marks and should be read as such wherever they occur in this document:

CENELEC

ERTMS

ETCS

IEC

Intellectual Property Office is an operating name of the Patent Office www.gov.uk/ipo

TRAIN INTEGRITY DETERMINATION

Field of the Invention

The present invention relates to a system for determining the integrity of a train composed of coupled rolling stock vehicles.

Background

Ensuring train integrity is critical for safe operation of railway networks.

One known system for determining train integrity detects the position of the tail of the train by an end-of-train (EOT) GPS device. The position of the tail device is then transmitted by radio to an evaluation unit installed on the leading vehicle. However, problems can arise due to incomplete satellite signal coverage caused by shading due to e.g. buildings, topography and tunnels.

Other EOT systems include: radio devices located at the head and tail of the train, along with evaluation of the signal transmission time between the devices; detection of brake air pipe pressure reduction on the tail vehicle and radio transmission of the status to an evaluation unit on the leading vehicle; and a device on the tail vehicle which feeds acoustic waves into the brake air pipe for evaluation by the leading vehicle.

Systems relying on EOT devices and/or GPS are generally used on freight railways running on networks without trackside signalling infrastructure. However, as well as the technical limitations of such systems caused by physical constraints such as satellite coverage and air brake pipe behaviour, the need to mount an EOT device constrains railway operations, as procedures have to be established and staff provided to ensure that a suitable EOT device is available and mounted on the last car whenever a train is composed. Such operational constraints are incompatible with the logistical requirements of high performance railways.

In addition, due to the latency of the pressure reduction in an air brake pipe when a train is separated, systems monitoring the pneumatic brake pressures may not offer the performance needed on main lines operated with short headways.

Thus other train-based approaches not reliant on EOT devices have been developed. For example, ultrasonic signals can be fed into the rails across the wheels of the leading vehicle, followed by detection of the spacing and number of wheels by evaluation of the reflections provided by the wheels of the subsequent cars. Another approach is to monitor several parameters of the air brake pipe on the leading vehicle, such as pressure and volumetric air flow. Indeed, measurement acoustic waves can be fed into the air brake pipe. However none of these approaches has sufficient reliability. For example, it is difficult to reliably detect brake pipe leakage somewhere along a train with low latency times on the leading vehicle. Moreover, acoustic waves fed into the air brake pipe are heavily reflected and attenuated at high frequencies. Thus practical frequencies for such waves would typically be between 10 and 20 Hz, but in this range there are considerable disturbances caused by the noise of the train movement, especially when the brakes are applied.

Yet another approach is taken by systems which make use of trackside infrastructure. Such systems can transmit start of train and end of train signals to a trackside device and back to the train for confirmation of train integrity. Another option is to compare the number of known axles with the number of axles counted by a trackside device. However systems requiring trackside infrastructure incur high installation and maintenance costs.

Thus it would be desirable to have an on-board system for determining train integrity which is reliable, provides low latencies, and is relatively low cost.

Summary

Accordingly, in a first aspect, the present invention provides a system for determining the integrity of a train composed of coupled rolling stock vehicles, the system including:

a control unit for installation in one of the vehicles;

a first electrical bus extending from the control unit and, in use, running the length of the train between a front one and a rear one of the vehicles;

and plural first RFID tags for mounting on respective of the vehicles, each first tag being operatively connected to the bus to allow communication between the first tag and the control unit;

wherein each first tag encodes a unique identifier which is interrogatable by the control unit to uniquely identify the vehicle to which it is mounted; and wherein the control unit is configured to interrogate the first tags and thereby to determine the integrity of the train.

Advantageously, RFID tags are reliable, cheap, and can be interrogated with low latency by hard-wired electrical connections (i.e. via the first bus). In addition, they can be provided with read-only unique identifiers which are highly resistant to being corrupted, which is important in a system which has a very low tolerance to false positives (i.e. false detection of a lost vehicle must be avoided because of the disruption to railway services which lost vehicles can cause).

The system can be used on both low traffic density railway lines and high-speed lines with high traffic density. Furthermore, by reducing average headways, the system can promote more efficient utilisation of railway networks. The system allows the train itself to determine its own integrity, so that conventional wayside train detection systems such as trackside circuits and axle counters are not needed, thereby helping to reduce infrastructure installation and maintenance costs.

In a second aspect, the present invention provides a train composed of coupled rolling stock vehicles and fitted with the system according to the first aspect.

Optional features of the invention will now be set out. These are applicable singly or in any combination with any aspect of the invention.

The control unit may be configured to store a record of the unique identifiers of the first tags. The control unit can then determine the integrity of the train by comparing the unique identifiers of the first tags obtained by the interrogation thereof with the stored record of the unique identifiers of the first tags.

The control unit may be configured to repeatedly interrogate the first tags and thereby to determine the integrity of the train. In this way, the train operator can be continually updated on the integrity of the train.

Conveniently, pluggable electrical connectors may extend the first bus across neighbouring vehicles of the train such that the first bus can be electrically terminated at any pair of neighbouring vehicles by unplugging the respective connectors. For example, the electrical connectors may be integrated with mechanical coupling devices of the vehicles such that the first bus is electrically terminated at any pair of neighbouring vehicles when those neighbouring vehicles are mechanically decoupled from each other.

Each first tag may encode the unique identifier as a read-only identifier. In this way, the system can ensure that the identifiers are not alterable, thereby assuring the reliability and robustness of the system. Each first tag may further encode other read-only information, such as the length of the respective vehicle.

Each first tag may be configured to encode read-write data. Typically these data are less critical for train integrity determination, and can include information such as the respective vehicle number, and the respective vehicle keeper marking.

The first tags are preferably encased by hermetically sealed enclosures. In this way the tags are protected against ingress of water, dirt and other environmental agents.

The system may further include: a second electrical bus extending from the control unit and, in use, running the length of the train between the front one and the rear one of the vehicles; and plural second RFID tags for mounting on respective of the vehicles, each second tag being operatively connected to the bus to allow communication between the second tag and the control unit; wherein each second tag encodes a unique identifier which is interrogatable by the control unit to uniquely identify the vehicle to which it is mounted; and wherein the control unit is also configured to interrogate the second tags and thereby to determine the integrity of the train. By providing two electrical buses and two series of RFID tags, the system has built-in redundancy, improving its reliability and robustness up to safety integrity level 4, i.e. SIL 4 as defined by Railway CENELEC standards EN 50126/50128/50129. Optional features of the first tags and the first bus discussed above pertain also to the second tags and the second bus. For example, the control unit may be configured to store a record of the unique identifiers of the second tags. The control unit can then determine the integrity of the train by comparing the unique identifiers of the first and the second tags obtained by the interrogations thereof with the stored records of the unique identifiers of the first and the second tags. Each first or second tag of a given vehicle may further encode as read-only information the unique identifier of the counterpart tag of that vehicle.

In a train composed of coupled rolling stock vehicles and fitted with the system, the RFID tags may conveniently be mounted on sides of the vehicles, e.g. accessible for external interrogation. In particular, when the system has two electrical buses and two series of RFID tags, the first tags may be mounted on one lateral side of the train and the second tags may be mounted on the opposing lateral side of the train.

Brief Description of the Drawings

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 shows schematically an on-board train integrity system;

Figure 2 shows schematically, for just a head locomotive and a following vehicle, a control unit, a left electrical bus and corresponding RFID tags of the system of Figure 1;

Figure 3 shows the head locomotive of Figure 2 when uncoupled from the following vehicle, and a close-up schematic view of the terminated electrical bus;

Figure 4 shows the head locomotive of Figure 2 when coupled or about to be coupled to the following vehicle, and a close-up schematic view of the extended electrical bus;

Figure 5 shows schematically (a) a vehicles control unit table for a train composed of five vehicles, (b) an initial scan phase performed by a control unit of a train integrity system and (c) a subsequent polling cycle performed by a control unit of the train integrity system.

Detailed Description and Further Optional Features

The present invention provides an on-board train integrity system (TIS), for providing realtime and safe information (at CENELEC SIL 4) about rolling stock completeness, length and composition throughout a train’s whole journey and also during train composition activities.

The TIS, which is modular and distributed across all the rolling-stock vehicles (e.g. wagons, coaches, traction units etc.) using preferably two network buses, is shown schematically in Figure 1. It is driven by an on-board control unit 1, typically located in the locomotive 2a which forms the head vehicle of the coupled rolling stock vehicles 2a-d of the train, although the TIS may have plural such units, e.g. a control unit may be located at each end of the train. The control unit can be a specific TIS master unit or can be part of a more general onboard TCS (e.g. the European vital computer (EVC) of an on-board European railway traffic management system (ERTMS) or European train control system (ETCS) subsystem). The control unit interfaces a left series of passive RFID tags 3a-d, and a right series of passive RFID tags 4a-d, the series of tags being connected to the control unit via respective left 5 and right 6 electrical buses which run the length of the train between the head vehicle 2a and the rear vehicle 2d, with one tag for each rolling stock vehicle within each series. The buses can be multi-point serial network buses or the like.

Each RFID tag 3a-d, 4a-d provides internal and read-only information to the control unit 1. This information includes its unique ID, but it can also provide other read-only information, such as the ID of the counterpart RFID tag on the other side of the same vehicle, the length of the vehicle and other vehicle information. More particularly, the unique ID is hard-wired into the tag itself and preferably uses at least 3-bytes (24 bits) for its coding. Each tag can also provide read-write information, such as its vehicle number, and its vehicle keeper marking. The tags are configured to be used in harsh environments, and thus preferably have a hermetically sealed rigid polycarbonate plastic enclosure, e.g. conforming at least to IP67 (or at least to IP68 or IP69K) classification under International Electrotechnical Commission (IEC) standard 60529.

The control unit 1 stores the historical composition of the train, and thus is able to compare the information received from the tags 3a-d, 4a-d with its stored knowledge of what the composition should be. If the comparison indicates that one or more vehicles have been lost, then suitable action can be taken by the control unit, such as alerting the driver who can in turn report to a track supervisor. The two independent series of tags provide redundancy so that if a malfunction occurs in one of the buses, in one of the tags, or in the interfacing of a bus to one of the tags, the system can still determine the integrity of the train based on the bus and the tags of the other series. However, in this case, the control unit may issue a maintenance alert in the event of a discrepancy in the data provided by the two series of tags.

The control unit 1 can read, either repeatedly at a given intervals or on demand from e.g. an ETCS, the information from the two series of tags 3a-d, 4a-d, thereby obtaining information in a safe and reliable way (i.e. consistent with SIL 4) about train integrity, length and composition during (i) the whole of a journey, (ii) any scheduled operational train composition activity, and (iii) any accidental or other operational change in rolling stock composition, whether at standstill, in stations/depots/yards, or any other time. Thus the control unit can dynamically handle any composition activities and any lost rolling stock vehicles without any need of for coupling staff intervention. Moreover, the TIS is compatible with freedom of rolling stock composition (i.e. an unlimited number of vehicles can be queued/de-queued and/or inserted/removed from the train), no constraints on vehicle positioning in a train composition, and no constraints on selection of the tail vehicle. Advantageously, the TIS can be composed exclusively of on-board components, and so does not require any wayside equipment to realize its functions. The interrogation of the tags can be performed via a broadcast request from the control unit to all the tags, or can be via tag-by-tag individual requests from the control unit.

Although the RFID tags 3a-d, 4a-d have wired interfaces to the buses 5, 6, the data carried by the tags can also be read externally, e.g. wirelessly by a suitable RFID reader. Thus typically the left and right series of tags are mounted on opposing lateral sides of the train for convenient external interrogation. For example, the tags can be located on each vehicle adjacent to standard vehicle labels.

Figure 2 shows schematically, for just the head locomotive 2a and the following vehicle 2b, the control unit 1, the left bus 5 and the corresponding tags 3a, 3b. The control unit and the tags communicate with the bus over respective bus interfaces 7. Electrical connectors 8 on the neighbouring vehicles plug into mating connectors at the ends of a joining cable 9 to extend the bus across the neighbouring vehicles. These connectors can be straightforwardly plugged and unplugged during commissioning and service works (e.g. train composition) inside the coupling areas of the locomotive and the other vehicles. Thus Figure 3 shows the head locomotive 2a when uncoupled from the following vehicle, the unplugged connector 8 of the head locomotive closing the loop of the bus 5, and Figure 4 shows the head locomotive 2a when coupled or about to be coupled to the following vehicle 2b, the plugged connectors 8 of the neighbouring vehicles and the joining cable 9 extending the bus across the vehicles. Figures 3 and 4 both also show respective close-up schematic views of respectively the terminated bus and the extended bus.

Separate joining cables 9 may be needed for extending the buses 5, 6 across freight wagons, which typically have unsophisticated coupling arrangements. However, in a variant arrangement (not illustrated) the connectors of the neighbouring vehicles may be plugged directly to each other (i.e. without the intermediary of a joining cable). The connectors can then be integrated with mechanical coupling devices 10 of the vehicles so that mechanical coupling/decoupling of the vehicles automatically causes extension/termination of the bus.

Preferably, the control unit 1 and the tags 3a-d, 4a-d are suitable to be automatically “hotpluggable” directly onto the buses 5, 6 and to be recognized, linked and used after a short (few seconds) transient re-configuration time.

Figure 5 shows schematically (a) a vehicles control unit table for a train composed of five vehicles, (b) an initial scan phase performed by a control unit of the TIS and (c) a subsequent polling cycle performed by a control unit of the TIS.

More particularly, as shown in Figure 5(a), the train has a lead vehicle (#001) which is a locomotive containing a control unit, three following vehicles (#002, #003 and #004) which are a coach, a wagon and another coach, and then a rear vehicle (#005) which is another locomotive containing a control unit. The two locomotives have left and right RFID tags connected to the left and right buses at their respective control units (the buses starting and ending at the control units), while the three central vehicles have left and right RFID tags connected to the left and right buses as they extend between the two control units. Each RFID tag has a unique 24 bit identifier, and each connection between a tag and a bus has a 7 or 10 bit address in the control unit of the lead vehicle.

In the initial scan phase shown in Figure 5(b), the control unit of the lead vehicle uses a broadcast read command to build the entries for the table of Figure 5(a), which is then stored in the control unit memory. In the scan phase, each connection to an RFID tag is interrogated, and as well as the unique identifier of the tag at that connection, other data stored by the tag (such as the vehicle length, the vehicle ID number, the unique identifier of the tag on the other side of the vehicle etc.) are retrieved (in multiple banks) and used to form the table.

Then, in the subsequent and repeatedly performed polling cycle shown in Figure 5(c), each RFID tag in the table is checked by confirming the RFID tag unique identifier from each connection. Also the polling cycle performs another broadcast read to check that there are no new connections to new RFID tags.

A possible hazard condition can arise in the unlikely event that both the left and right RFID tags of a given vehicle malfunction while both the electrical buses continue unterminated across that vehicle. However, this possible hazard condition can be mitigated by confirming that the number of vehicles composing the train, as determined by the TIS, is correct before the train starts its journey. A further possible hazard condition can arise if one or more TISincompatible vehicles are inserted into the train composition. In this possible hazard condition, train integrity can be guaranteed only as far as the uninterrupted extension of the buses from the control unit. For example, if one or more TIS-incompatible vehicles are coupled to the rear of the train, then these vehicles will not be included in the integrity determination. As another example, If one or TIS-incompatible vehicles are inserted between the front and rear vehicles then not only will the TIS-incompatible vehicles not be included in the integrity determination, but also all the vehicles from the inserted vehicles to the rear of the train which were previously included in the determination will no longer be included.

The TIS is suitable for use on freight vehicles, locomotives, passenger vehicles, freight wagons, on-track maintenance vehicles, railway compatible freight trailers and, where applicable, any other vehicles regularly moving on rail.

While the invention has been described in conjunction with the exemplary embodiments 5 described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

Claims

1. A system for determining the integrity of a train composed of coupled rolling stock vehicles, the system including:

a control unit for installation in one of the vehicles;

2. A system according to claim 1, wherein the control unit is configured to store a record of the unique identifiers of the first tags.

3. A system according to claim 2, wherein the control unit determines the integrity of the train by comparing the unique identifiers of the first tags obtained by the interrogation thereof with the stored record of the unique identifiers of the first tags.

4. A system according to any one of the previous claims, wherein the control unit is configured to repeatedly interrogate the first tags and thereby to determine the integrity of the train.

5. A system according to any one of the previous claims, wherein pluggable electrical connectors extend the first bus across neighbouring vehicles of the train such that the first bus can be electrically terminated at any pair of neighbouring vehicles by unplugging the respective connectors.

6. A system according to claim 5, wherein the electrical connectors are integrated with mechanical coupling devices of the vehicles such that the first bus is electrically terminated at any pair of neighbouring vehicles when those neighbouring vehicles are mechanically decoupled from each other.

7. A system according to any one of the previous claims, wherein each first tag encodes the unique identifier as a read-only identifier.

8. A system according to any one of the previous claims, wherein each first tag is configured to encode read-write data.

9. A train according to claim 8, wherein the first tags are mounted on one lateral side of the train and the second tags are mounted on the opposing lateral side of the train.

Intellectual

Property

Office

Application No: GB1704302.7 Examiner: Dr Maurice Blount

9. A system according to any one of the previous claims, wherein the first tags are encased by hermetically sealed enclosures.

10. A system according to any one of the previous claims, wherein the system further includes:

a second electrical bus extending from the control unit and, in use, running the length of the train between the front one and the rear one of the vehicles; and plural second RFID tags for mounting on respective of the vehicles, each second tag being operatively connected to the bus to allow communication between the second tag and the control unit;

wherein each second tag encodes a unique identifier which is interrogatable by the control unit to uniquely identify the vehicle to which it is mounted; and wherein the control unit is also configured to interrogate the second tags and thereby to determine the integrity of the train.

11. A system according to claim 10, wherein the control unit is configured to store a record of the unique identifiers of the second tags.

12. A system according to claim 11, wherein the control unit determines the integrity of the train by comparing the unique identifiers of the first and the second tags obtained by the interrogations thereof with the stored records of the unique identifiers of the first and the second tags.

13. A train composed of coupled rolling stock vehicles and fitted with the system according to any one of the previous claims.

14. A train according to claim 13, wherein the tags are mounted on sides of the vehicles.

15. A train composed of coupled rolling stock vehicles and fitted with the system according to any one of claims 10 to 12, wherein the first tags are mounted on one lateral side of the train and the second tags are mounted on the opposing lateral side of the train.

Amendments to the claims have been filed as follows :CLAIMS

Ί“2Ό

a control unit for installation in one of the vehicles;

a first electrical bus and a second electrical bus, each bus extending from the control unit and, in use, running the length of the train between a front one and a rear one of the vehicles;

plural first RFID tags for respectively mounting on all of the vehicles of the train, each first tag being operatively connected to the first bus to allow communication between the first tag and the control unit; and plural second RFID tags for respectively mounting on all of the vehicles of the train, each second tag being operatively connected to the second bus to allow communication between the second tag and the control unit;

wherein each first tag encodes a unique identifier which is interrogatable by the control unit to uniquely identify the vehicle to which it is mounted, and each second tag encodes a unique identifier which is interrogatable by the control unit to uniquely identify the vehicle to which it is mounted;

wherein the control unit is configured to store a record of the unique identifiers of the first tags and a record of the unique identifiers of the second tags; and wherein the control unit is configured to compare the unique identifiers of the first and the second tags obtained by the interrogation thereof with the stored records of the unique identifiers of the first and the second tags and thereby to determine the integrity of the train.

2. A system according to claim 1, wherein the control unit is configured to repeatedly interrogate the first and the second tags and thereby to determine the integrity of the train.

25 3. A system according to claim 1 or 2, wherein pluggable electrical connectors extend the first and the second buses across neighbouring vehicles of the train such that the first and the second buses can be electrically terminated at any pair of neighbouring vehicles by unplugging the respective connectors.

4. A system according to any one of the previous claims, wherein each first and second

30 tag encodes the unique identifier as a read-only identifier.

5. A system according to any one of the previous claims, wherein each first and second tag is configured to encode read-write data.

6. A system according to any one of the previous claims, wherein the first and second tags are encased by hermetically sealed enclosures.

5 7. A train composed of coupled rolling stock vehicles and fitted with the system according to any one of the previous claims.

8. A train according to claim 7, wherein the tags are mounted on sides of the vehicles.