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(11) | EP 1 752 355 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Train control system |
| (57) A train control system comprises an interlocking for producing signalling information,
processing equipment for communication with a train for relaying safety information
therebetween and an interface between the interlocking and the processing equipment,
wherein the interface is bi-directional to enable signals to be passed between the
processing equipment and the interlocking in both directions, and the processing equipment
passes indications between the processing equipment and the interlocking that modify
interlocking functions and / or enable delegation of specific interlocking functions
to the processing equipment.
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[0002] Conventionally, an interlocking is responsible for maintaining the safety of train movements across sections of track which have been set, locked and held for use by a particular train. Functions such as route setting, route locking, aspect control and route release are among the features commonly implemented according to standard signalling practice within an interlocking. These functions conventionally are based on information from physical train detection sections, such as track circuits or axle counter sections.
[0003] By adding specialised processing and communications equipment both at the trackside for example and on each train, it is possible to enhance the operation of the railway by providing automatic train control. There are various examples in operation and in development, in particular that of the European Train Control System (ETCS), part of the European Rail Traffic Management System (ERTMS). Use of this additional equipment provides, amongst other things, the possibility of running trains faster and at closer headway than would be allowed by using lineside signalling alone. A train which incorporates this additional equipment, and thus has the additional functionality of automatic train protection (ATP) and the ability to be communicated with, is hereafter called a "fitted train". An "unfitted" train does not have this equipment and so is driven based on manual observation of signal aspects only.
[0004] Typically in a communication-based train control system, the equipment on each fitted train determines the absolute position of the train within the railway. The train-carried equipment then reports this position within the railway to processing equipment e.g. Trackside Processing Equipment (TPE) via the communication system either at frequent intervals or when reaching a defined location.
[0005] The trackside processing equipment monitors signalling information from the interlocking and determines from this information, and possibly also from its knowledge of other train locations, the extent to which an authority can be given for a train to proceed along the railway. This movement authority may then be communicated to the train-carried equipment from the trackside processing equipment.
[0006] Using its knowledge of train and track characteristics, the location of the train and the movement authority issued to the train, the train-carried equipment calculates one or more braking profiles for the train which may then be used to ensure that the train does not exceed the movement authority it has been given.
[0007] It is clear that this integration of a communication-based train control system with conventional trackside signalling introduces diverse sources of train location information, with associated timing issues, and a shared responsibility for some of the signalling functions. This raises a number of functional implications for the system as a whole, for example:
- (i) The authority to proceed beyond a route entry point may be issued from the trackside processing equipment to a train at any location of the train, unrelated to the sighting of any lineside signals.
- (ii) If an authority to proceed beyond a route entry point is withdrawn at the trackside, the recognition by the train-carried equipment that the authority has been removed is not directly related to the replacement of any lineside signal aspects.
- (iii) Where conventional lineside signals exist, any movement authority must be consistent with the signal aspects being displayed and should not require aspects to have different meanings for a driver depending on the train being operated.
- (iv) The trackside processing equipment has to be able to distinguish between removal of authority due to a train entering a route and removal of authority due to route cancellation.
[0008] It is an object of the present invention to provide a train control system which addresses the aforementioned implications. This is achieved by the use of a novel interface between interlocking equipment, as may be applied for signalling purposes to a conventional railway, and trackside processing equipment which communicates safety related information to and receives safety related information from one or more trains within a defined area of the railway. In particular, this interface enables a bi-directional flow of information between the interlocking equipment and the processing equipment. Such an interface provides enhancements to operational safety, reliability and performance for a fitted railway. An important factor contributing to these benefits is the implementation of a closed loop method of control which safely manages the diverse sources of train location information.
[0009] In accordance with a first aspect of the present invention there is provided a train control arrangement comprising an interlocking for producing signalling information, processing equipment for communication with a train for relaying safety information therebetween and an interface between the interlocking and the processing equipment, wherein the interface is bi-directional to enable signals to be passed between the processing equipment and the interlocking in both directions.
[0010] In accordance with a second aspect of the present invention there is provided a method of train control for use with an arrangement comprising an interlocking and processing equipment, the method comprising the step of passing indications from the processing equipment to the interlocking that modify interlocking functions.
[0011] With this method, signals may be sent to the processing equipment from the interlocking to enable delegation of specific interlocking functions to the processing equipment.
[0012] In accordance with a third aspect of the present invention there is provided a train control system comprising an interlocking for producing signalling information, processing equipment for communication with a train for relaying safety information therebetween and an interface between the interlocking and the processing equipment, wherein the interface is bi-directional to enable signals to be passed between the processing equipment and the interlocking in both directions, and the processing equipment passes indications between the processing equipment and the interlocking that modify interlocking functions and / or enable delegation of specific interlocking functions to the processing equipment.
[0013] The processing equipment may indicate to the interlocking routes where an approaching train is under control of the processing equipment. The processing equipment may indicate that the train approaching a route is under control of the processing equipment if the interlocking indicates that there is a valid route set. The processing equipment may indicate that the train approaching a route is under control of the processing equipment when the train is in possession of an authority that allows movement up to the route entry point. Alternatively or additionally, the processing equipment may indicate that the train approaching a route is under control of the processing equipment when the train reports a location such that the front of the train is within a defined distance in rear of the route entry point.
[0014] Preferably, the interlocking provides a route specific proceed indication to the processing equipment that indicates the processing equipment may authorise the approaching train into that specific route. The interlocking may provide a route specific proceed indication to the processing equipment if the appropriate signalling conditions allowing route entry are satisfied and the processing equipment indicates that the train approaching a route is under control of the processing equipment. The interlocking may maintain the route specific proceed indication until one of the following occur:-
- a) the processing equipment removes the indication to the interlocking that the next approaching train is under control of the processing equipment; or
- b) the interlocking detects a set of conditions in which the emergency removal of the route specific proceed indication is necessary.
[0015] In this case, the processing equipment may remove the indication to the interlocking that the train approaching a route is under control of the processing equipment if the train reports to the processing equipment that the front of the train has passed the route entry point. Alternatively and/or additionally, the processing equipment may remove the indication to the interlocking that the train approaching a route is under control of the processing equipment if the interlocking removes the indication that there is a valid route set, or the processing equipment may remove the indication to the interlocking that the train approaching a route is under control of the processing equipment if the authority issued to the train no longer allows movement up to the route entry point.
[0016] Advantageously, the interlocking may only set a specific lineside proceed aspect if a route specific proceed indication has been provided to the processing equipment.
[0017] Preferably, the processing equipment indicates to the interlocking the individual routes that are subject to external approach locking. The processing equipment may indicate that a route is subject to external approach locking when the train approaching the route is under control of the processing equipment and the interlocking indicates that there is a valid route set.
[0018] The interlocking may prevent the release of a route if the processing equipment indicates that the routes are subject to external approach locking.
[0019] The interlocking may provide a route specific proceed indication to the processing equipment that indicates the processing equipment may authorise the approaching train into that specific route. The interlocking may only provide a route specific proceed indication to the processing equipment if the appropriate signalling conditions allowing route entry are satisfied and the processing equipment indicates that the route is subject to external approach locking. The processing equipment may remove the indication to the interlocking that a route is subject to external approach locking when the interlocking removes the route specific proceed indication and the processing equipment no longer requires external approach locking to be held. The processing equipment may no longer require external approach locking if the train reports to the processing equipment that the front of the train has passed the route entry point. Alternatively and/or additionally the processing equipment may no longer require external approach locking if an authority past the route entry point has not been issued to the train by the processing equipment, or if a previously issued authority past the route entry point has been withdrawn and the train indicates that it has stopped or is able to stop in rear of the route entry point, or if a previously issued authority past the route entry point has been withdrawn and sufficient time has elapsed for the train to cancel its own movement authority and for the train to come to a stand.
[0020] The invention will now be described, by way of example, with reference to the accompanying drawing, in which:-
Fig. 1 schematically shows a train control arrangement in accordance with the present invention.
Fig. 1 shows a train control arrangement comprising an interlocking which may control signalling and track switching, and which receives train detection signals. Also shown is trackside processing equipment connected to radio communications equipment for exchanging safety related information with equipment onboard a train. The interlocking and trackside processing equipment are linked via a bi-directional interface.
In the following description, the present invention is described with reference to "normal" functions of a railway signalling system, such as route locking and release.
Route Setting and Providing Authority
[0021] As for conventional signalling, a route is set on a signal to signal basis. There might not actually be a lineside signal at the start or the end of each route, but the concept of a signal to signal route remains in terms of interlocking logic and interaction with the Trackside Processing Equipment (TPE). Also the interlocking retains responsibility for all route-based functions, for example locking, releasing, etc., although it uses information provided by the TPE in addition to that from the trackside. Where lineside signals exist, a separate aspect for fitted trains may be provided.
[0022] In order to give the correct authority to an approaching train, the interlocking needs to know if the train is fitted or not and is under control of the TPE. The TPE needs to know which route has been set and when it is safe for a train to enter the route so that it can issue a correct movement authority. The following indications are provided on the TPE-I/L interface to achieve these functions:
| Indication | From | To | Purpose |
| Route Authorised | I/L | TPE | Advises the TPE that a valid route has been set from a route entry point for any train. There must be one Route Authorised for each route from the route entry point, allowing the TPE to determine which route has been set. |
| Request To Proceed | TPE | I/L | Informs the interlocking that a fitted train under the control of the TPE is the next train approaching the route entry point. The TPE uses this indication to request the interlocking to authorise a TPE controlled train to enter the route. There only needs to be one Request To Proceed for each route entry point. |
| Proceed | I/L | TPE | Indicates that the interlocking has locked the route, any aspect or route entrance conditions are clear and the TPE has requested a proceed indication. It is safe for the TPE to extend a movement authority beyond the route entry point. There only needs to be one Proceed indication for each route entry point, although different Proceed indications may be used for different types of route. |
| TPE Approach Locking | TPE | I/L | Holds the route locked whilst a train in rear of the route entry point may be in possession of a valid movement authority for the route. There only needs to be one TPE Approach Locking indication for each route entry point. |
[0023] When a route is called from a control system, the route, if available, is set and locked by the interlocking in the normal way. Once the route is set and locked, the interlocking may clear any trackside signal, if one exists and the route is clear, according to the conventional lineside aspect sequence. This allows an unfitted train to enter the route in the normal way. The interlocking also passes the route information to the TPE in the form of a 'Route Authorised' indication which indicates the route entry point and the route from it that is being set. This route indication can be sent from the interlocking after the route has been set and locked or at any time during the setting of the route.
[0024] If, having received the Route Authorised information, the movement authority for a train reaches this route entry point (or has already reached it), then the TPE indicates this to the interlocking by setting the TPE Approach Locking bit for that route together with the Request to Proceed. Once the route has been set and locked and the TPE has applied approach locking for the route together with a request for a train to proceed past the route entry point, the interlocking replies with a Proceed indication to the TPE and can display any additional lineside aspect to the approaching fitted train. Once the Proceed indication is received from the interlocking, the TPE can issue a movement authority to the train that allows movement into the route.
[0025] The same process is repeated to extend the movement authority past each route entry point in turn. The order in which a route is called or an MA reaches the entry point is not important, the TPE waits until both conditions are satisfied before applying TPE approach locking and requesting a proceed.
[0026] An exception exists for a train that is communicating with the TPE but has not been given any movement authority. In this case, the TPE will only set the TPE Approach Locking bit and Request to Proceed for a route for which Route Authorised is set if the train reports a location indicating that the front of the train is within a defined distance in rear of the route entry point. This is a process called 'Proving Clear Ahead' and ensures that there can be no second train between the first communicating train and the route entry point but unknown to the TPE. The defined distance is chosen such that if a second train were to exist then it would have to occupy the route in advance of the route entry point in order to allow the first communicating train to enter the defined distance in rear of the entry point. If the interlocking detects any train entering a route it will inhibit the setting of a Proceed authority to the TPE, if it has not been set already, until the conditions for detecting route entry have normalised.
[0027] The interaction between the TPE and the interlocking ensures that at every lineside signal for which the train has a proceed authority, the driver of a fitted train is presented with the additional aspect irrespective of the extent of that authority in advance of the signal. In addition, this interaction also ensures that it is only the drivers of fitted trains who are presented with the additional aspect; drivers of unfitted trains continue to see normal aspect sequences.
[0028] The interaction between the TPE and the interlocking also ensures that before a movement authority is issued to a train to pass a route entry point, full approach locking is applied even though the train may not be within the conventional approach locking distance of the route entry point.
Route Releasing
i) Train in Route
[0029] The normal process of route releasing occurs after the train has entered the route. For a fitted train, it is necessary for both the interlocking and the TPE to detect the train in the route before normal route release can commence. The interlocking detects a train entering a route using train detection sections, whereas the TPE may use the reported location from the train. There may therefore be a difference in timing of this information between the interlocking and the TPE, however the sequence of detection is not important.
[0030] The interlocking maintains the Proceed indication to the TPE until the TPE removes its Request to Proceed, even if the interlocking has detected the train as being in the route. This is to ensure that, from the TPE's viewpoint, the proceed authority does not appear to be replaced in front of the apparent (i.e. last reported) location of the train. Similarly, the interlocking must not begin route release until the TPE Approach Lock has been removed, even if the conventional route release conditions have been satisfied. It is possible, however, for the interlocking to remove the Route Authorised indication and replace the aspect of lineside signals to danger once the conventional conditions for 'train entered route' are satisfied.
[0031] When the train reports a location in the route, the TPE removes Request to Proceed on the interface to the interlocking. The interlocking responds by removing the Proceed indication on the TPE interface and the TPE responds to this by removing the TPE Approach Locking.
[0032] The TPE will not re-assert Request to Proceed until the Route Authorised clears and becomes set again and the interlocking will not re-assert Route Authorised until TPE Approach Locking has been removed. This ensures that the interaction completes for each train and eliminates any possibility of misinterpreting a Proceed authority for the wrong train.
ii) Route Cancelled
[0033] If the signalman requests the cancellation of a route in front of a train, this will cause any lineside signal to be replaced. The cancellation request is also passed to the TPE, if appropriate, by the removal of both the Proceed and the Route Authorised for that route. Depending on the location and speed of the train, there are different conditions that must be satisfied before the route can be released. In each case, both the interlocking and the TPE must release their own approach locking before the route can release. The interlocking applies conventional approach locking using the same conditions as it would without the TPE. For an unfitted train, this would be the only approach locking applied. For a fitted train, the TPE additionally applies its own approach locking. To allow for earlier indication of proceed authority and faster train speeds, the TPE approach locking is likely to apply over a greater distance than that of the interlocking. For a fitted train that is not within the conventional approach locking distance of the start of the route when the route is cancelled, the TPE approach locking would be the only locking applied. The release of the conventional interlocking approach locking is as normal for the particular railway and is not described in detail here.
[0034] The release of TPE Approach Locking can result from a number of different scenarios. Briefly, TPE Approach Locking may be removed:
- a) immediately if no movement authority into the cancelled route has yet been issued to the train; or
- b) once a shorter authority to the start location of the cancelled route has been issued to the train and the train either stops or confirms that it is able to stop in rear of that location; or
- c) after a short time delay if the train reports that it has entered the route. The short delay is to ensure that the interlocking will also have detected the train in the route before TPE Approach Locking is removed.
[0035] To allow for possible loss of communication with the train, the TPE can also release its approach locking after the timeout of a timer. The length of this timer ensures that the train will have timed out its own movement authority and that the train has time to come to a stand.
[0036] A further possibility is that communication between the interlocking and the TPE is lost, in which case the interlocking will run a timer before assuming that TPE approach locking has been released. This timer again allows for the possible worst case delay in removing the movement authority from the train and the train coming to a stand.
[0037] As stated above, if a train indicates that it can stop safely in rear of a new shortened movement authority then the TPE can remove its own TPE Approach Locking. This removal of TPE Approach Locking can be utilised within the interlocking logic to override its own approach locking for a fitted train and release the cancelled route far sooner than would be possible with conventional logic, thus providing a significant performance improvement.
Route Locking for a Second Train
[0038] After one train has entered a route, it is possible for a second and any subsequent train under TPE protection to also enter the same route. Whether or not another train is allowed into an occupied route is controlled by the logic within the interlocking and will depend on the operating rules and application requirements for a particular railway. Where such operation is allowed, the interaction between the TPE and the interlocking ensures that the interlocking maintains control over the sequence of events. After the first train enters, which may or may not be under TPE control, the interlocking must ensure that the route entry logic has normalised before starting the entry process again for a second train. As soon as the first train is detected in the route, the interlocking removes Route Authorised. This ensures a defined sequence is followed for each train rather than a design in which the TPE removes Request to Proceed for the first train and immediately re-asserts it for a second. The interlocking then waits until Request to Proceed, its own Proceed indication and TPE Approach Locking have all been removed and its own internal logic has normalised before allowing Route Authorised to become set for a second or subsequent train. The setting of Route Authorised allows the interaction between the interlocking and the TPE to begin again, if appropriate, for another train.
1. A train control arrangement comprising an interlocking for producing signalling information,
processing equipment for communication with a train for relaying safety information
therebetween and an interface between the interlocking and the processing equipment,
wherein the interface is bi-directional to enable signals to be passed between the
processing equipment and the interlocking in both directions.
2. A method of train control for use with an arrangement comprising an interlocking and
processing equipment, the method comprising the step of passing indications from the
processing equipment to the interlocking that modify interlocking functions.
3. A method according to Claim 2, wherein signals are sent to the processing equipment
from the interlocking to enable delegation of specific interlocking functions to the
processing equipment.
4. A train control system comprising an interlocking for producing signalling information,
processing equipment for communication with a train for relaying safety information
therebetween and an interface between the interlocking and the processing equipment,
wherein the interface is bi-directional to enable signals to be passed between the
processing equipment and the interlocking in both directions, and the processing equipment
passes indications between the processing equipment and the interlocking that modify
interlocking functions and / or enable delegation of specific interlocking functions
to the processing equipment.
5. A train control system according to Claim 4, wherein the processing equipment indicates
to the interlocking routes where an approaching train is under control of the processing
equipment.
6. A train control system according to Claim 5, wherein the processing equipment only
indicates that the train approaching a route is under control of the processing equipment
if the interlocking indicates that there is a valid route set.
7. A train control system according to Claim 6, wherein the processing equipment indicates
that the train approaching a route is under control of the processing equipment when
the train is in possession of an authority that allows movement up to the route entry
point.
8. A train control system according to either of Claims 6 and 7, wherein the processing
equipment indicates that the train approaching a route is under control of the processing
equipment when the train reports a location such that the front of the train is within
a defined distance in rear of the route entry point.
9. A train control system according to Claim 5, wherein the interlocking provides a route
specific proceed indication to the processing equipment that indicates the processing
equipment may authorise the approaching train into that specific route.
10. A train control system according to Claim 9, wherein the interlocking provides a route
specific proceed indication to the processing equipment if the appropriate signalling
conditions allowing route entry are satisfied and the processing equipment indicates
that the train approaching a route is under control of the processing equipment.
11. A train control system according to Claim 10, wherein the interlocking maintains the
route specific proceed indication until one of the following occur:-
a) the processing equipment removes the indication to the interlocking that the next approaching train is under control of the processing equipment; or
b) the interlocking detects a set of conditions in which the emergency removal of the route specific proceed indication is necessary.
12. A train control system according to Claim 11, wherein the processing equipment removes
the indication to the interlocking that the train approaching a route is under control
of the processing equipment if the train reports to the processing equipment that
the front of the train has passed the route entry point.
13. A train control system according to either of Claims 11 and 12, wherein the processing
equipment removes the indication to the interlocking that the train approaching a
route is under control of the processing equipment if the interlocking removes the
indication that there is a valid route set.
14. A train control system according to any of Claims 11 to 13, wherein the processing
equipment removes the indication to the interlocking that the train approaching a
route is under control of the processing equipment if the authority issued to the
train no longer allows movement up to the route entry point.
15. A train control system according to Claim 9, wherein the interlocking sets a specific
lineside proceed aspect if a route specific proceed indication has been provided to
the processing equipment.
16. A train control system according to Claim 5, wherein the processing equipment indicates
to the interlocking the individual routes that are subject to external approach locking.
17. A train control system according to Claim 16, wherein the processing equipment initially
indicates that a route is subject to external approach locking when the train approaching
the route is under control of the processing equipment and the interlocking indicates
that there is a valid route set.
18. A train control system according to Claim 16, wherein the interlocking prevents the
release of a route if the processing equipment indicates that the routes are subject
to external approach locking.
19. A train control system according to Claim 16, wherein the interlocking provides a
route specific proceed indication to the processing equipment that indicates the processing
equipment may authorise the approaching train into that specific route.
20. A train control system according to Claim 19, wherein the interlocking only provides
a route specific proceed indication to the processing equipment if the appropriate
signalling conditions allowing route entry are satisfied and the processing equipment
indicates that the route is subject to external approach locking.
21. A train control system according to Claim 20, wherein the processing equipment removes
the indication to the interlocking that a route is subject to external approach locking
when the interlocking removes the route specific proceed indication and the processing
equipment no longer requires external approach locking to be held.
22. A train control system according to Claim 21, wherein the processing equipment no
longer requires external approach locking if the train reports to the processing equipment
that the front of the train has passed the route entry point.
23. A train control system according to either of Claims 21 and 22, wherein the processing
equipment no longer requires external approach locking if an authority past the route
entry point has not been issued to the train by the processing equipment.
24. A train control system according to Claim 21, wherein the processing equipment no
longer requires external approach locking if a previously issued authority past the
route entry point has been withdrawn and the train indicates that it has stopped or
is able to stop in rear of the route entry point.
25. A train control system according to Claim 21, wherein the processing equipment no
longer requires external approach locking if a previously issued authority past the
route entry point has been withdrawn and sufficient time has elapsed for the train
to cancel its own movement authority and for the train to come to a stand.