Method for controlling a level crossing and railway installation for implementing such method

Abstract

Controlling a level crossing of a railway track by providing a train having an onboard processor communicating with a wayside processor associated to a level crossing, said train having a forward end and a rear end; moving the train forward along the railway track lowering down gates of the level crossing when train is at a predetermined distance upon detection of the train approaching the level crossing; when the forward end passes over a first reference point defining the beginning of an island area of the level crossing, sending a first message from the onboard safety processor towards the wayside processor informing that the train is approaching the level crossing; maintaining down gates; when the rear end passes over a second reference point defining the end of the island area, sending a second message from the onboard safety processor to the wayside processor informing that the train has left the level crossing; and lifting the gates.

Claims

1. A method for controlling a level crossing of a railway track comprising at least the following steps of: providing a train having an onboard processor arranged to determine a forward end and a rear end of the train by using a location determination system and to communicate with a wayside processor associated to a level crossing, said train extending between said forward end and said rear end; moving the train forward along the railway track in a predetermined direction so that the forward end and the rear end move correspondingly along the railway track in the same direction; lowering down gates of the level crossing upon detection of the train approaching the level crossing based on the actual location of the train; when the forward end passes over a first reference point defining the beginning of an island area associated to the level crossing, sending a first message from the onboard safety processor towards the wayside processor to inform that the train is approaching the corresponding level crossing; maintaining down gates of the level crossing; when the rear end passes over a second reference point defining the end of the island area, sending a second message from the onboard safety processor to the wayside processor to inform that the train has left the corresponding level crossing; and lifting the gates of the level crossing.

2. The method of claim 1, further comprising, after the step of sending a first message, a step of sending an acknowledgment message from the wayside processor to the onboard processor.

3. The method of claim 1, further comprising, after the step of sending a second message, a step of sending an acknowledgement message from the wayside processor to the onboard processor.

4. The method of claim 1, further comprising a step of sending, together with the first message, an expected time value which represents the time instant at which the second message is expected.

5. The method of claim 4, further comprising a step of sending to the wayside processor an updated time value in case the train slows down or stops after it enters in the island area.

6. The method of claim 4, further comprising, in case no second message is received within the expected time, a step of sending, from the wayside processor, a false activation message to a remote control unit notifying that the level crossing has been falsely activated.

7. The method of claim 6, further comprising a step of sending, from the remote control unit, a release crossing message to the wayside processor to allow it to lift the gates of the level crossing.

8. The method of claim 7, wherein the release crossing message is sent upon confirmation that the train has actually left the island area.

9. The method of claim 1, further comprising the step of providing an auxiliary backup train detection system at the level crossing in case of communication failures.

10. Railway installation comprising a railway track, a level crossing placed along said railway track, a train having an onboard processor arranged to move on said railway track towards the level crossing, and a wayside processor placed adjacent to said railway track, the wayside processor and the onboard processor being arranged to cooperate so as to implement a method according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further characteristics and advantages of the present invention will become apparent from the following description, provided merely by way of a non-limiting example, with reference to the enclosed drawings, in which:

(2) FIG. 1 shows a schematic lateral view of a train on a railway track;

(3) FIG. 2 shows a block diagram of the steps of a method for controlling a level crossing of a railway track according to the present invention;

(4) FIG. 3 shows a schematic graphic of the messages exchanged between an onboard processor and a wayside processor; and

(5) FIG. 4 shows a schematic graphic of alternatives messages exchanged between the onboard processor and the wayside processor of FIG. 3.

DETAILED DESCRIPTION

(6) Briefly, the method of the present invention is based on the exchange of messages between onboard and wayside safety processors to detect the presence of a train in an island area, this wayside safety processors being usually placed in a shelter adjacent to a level crossing. The solution uses the wireless train control system already existing between trains and wayside control units for exchanging signals for the activation of bars of the level crossing. The method requires that the onboard safety processor knows the location of the front and the rear ends of the train, and this can be accomplished by any location determination system (e.g. GPS, beacons, cab signals, etc.).

(7) FIG. 1 shows a schematic lateral view of a train 1 on a railway track 2 provided with an onboard safety processor 4 arranged to determine, in a manner known per se, a WCA (worst case ahead) point 6 and a WCB (worst case behind) 8 for the train 1. The WCA point 6 and WCB point 8 respectively define the two ends of the train 1, and a portion of the railway track 2 comprised between the WCA point 6 and the WCB point 8 corresponds to an area of occupancy of the train 1 on the railway track 2.

(8) In a preferred embodiment, a safety space 10 is added respectively after the WCA point 6 and before the WCB point 8, thus obtaining respective updated WCA point 6 and updated WCB point 8 to get a safer enlarged area of occupancy of the train 1 on the railway track 2.

(9) Advantageously, the railway track 2 is devoid of island track circuit and preferably also of approach track circuit. The approach track circuit being replaced, for example, by the use of the wireless train control system, a signal being wirelessly sent from the onboard safety processor 4 towards a control unit associated to the level crossing, thus allowing the latter to properly control the opening or closing of bars or gates placed in correspondence of the level crossing.

(10) In the following, a method for controlling a level crossing of a railway track according to the present invention is disclosed in detail, with reference to FIG. 2, which shows a block diagram of the steps of such a method.

(11) In a first step 100, a train of the type above disclosed is provided. Then, in step 102, the train 1 is moved forward along the railway track 2 in a direction A, so that the WCA point 6 and WCB point 8 move correspondingly along the railway track 2 in the same direction A.

(12) Subsequently, at step 104, a wayside processor, not shown in the figures, lowers down the gates of a level crossing, and preferably activates warning devices, upon detection, in a manner known per se, of the approach of the train 1 to the level crossing. For example, the gates are lowered when the train is a predetermined distance from the level crossing.

(13) Subsequently, at step 106, the WCA point 6 enters in a first island area placed along the railway track 2, as herein below disclosed. Then, at step 108 the onboard safety processor 4 sends to the wayside safety processor a first signal or message informing that the train 1 is approaching a corresponding level crossing.

(14) The island area is a portion of the railway track 2 placed in correspondence of a level crossing and is defined as the portion of the railway track 2 placed between respectively a first and a second reference point of said railway track 2, the first reference point being the first one along the direction A. The positions of said reference points are stored in a database onboard the train 1, which contains the positions of all the island areas present along the railway track 2.

(15) In step 106, therefore, the WCA point 6 passes over the first reference point during the movement of the train in the direction A.

(16) The train 1 continues its movement on the railway track 2 in the direction A, and the gates at step 109 are maintained down, until, at step 110, the train 1 exits the island area, in particular, the WCB point 8 passes over the second reference point.

(17) At subsequent step 112 the onboard safety processor 4 sends to the wayside safety processor a second signal or message informing that the train 1 has left the corresponding level crossing.

(18) At this point, at step 114, the wayside safety processor lifts the crossing gates and inactivates the warning devices.

(19) Specific messages, preferably with acknowledgements, are used to perform these operations, as disclosed herein below.

(20) FIGS. 3 and 4 shows a schematic graphic of the messages exchanged between the onboard processor 4 and the wayside processor.

(21) An island occupancy message 200, corresponding to the first message, is sent from the onboard safety processor 4 to the wayside processor at step 108, this island occupancy message 200 including an expected time value which represents the time instant t.sub.8 at which it is expected that the WCB point 8 will pass over the second reference point, based on current speed of the train 1. This allows the wayside safety processor to foresee when to expect the second message from the onboard processor 4 informing that the train 1 has left the corresponding level crossing, this being done as a safety measure in case of failure of the communication system.

(22) Advantageously, after the reception of the island occupancy message 200, an island occupancy acknowledgment message 202 is immediately sent back from the wayside processor to the onboard processor 4 to confirm correct receipt of the message 200.

(23) At step 112, an island cleared message 204 is sent from the onboard processor 4 to the wayside processor, and a corresponding island cleared acknowledgment message 206 is in turn preferably sent back.

(24) The dispatch of the island occupancy message 200 allows the onboard processor 4 to send also an updated time value t.sub.8 to the wayside processor in case the train 1 significantly slows down or stops after it has occupied the island. In particular, an updated occupancy message 200, which contains the updated time value t.sub.8, is sent to the wayside processor.

(25) If the expected time expires before the wayside processor has received from the onboard processor 4 the island cleared message 204, this means that the communications system may have failed. In this case, the wayside processor continues to keep the crossing gates down and the warning devices active but, as shown in FIG. 4, it sends also a false activation message 300 to a remote control unit notifying that the crossing may be falsely activated. A corresponding false activation acknowledgement message 302 is sent back from the remote control unit and the wayside processor.

(26) This allows performing a further verification about the real occupancy of the level crossing, for example by sending an operator on the site or by activating a video-surveillance etc.

(27) In a preferred embodiment of the invention, the remote control unit sends a release crossing message 304 to the wayside processor to allow it to lift the gates. This release crossing message 304 is sent after confirmation that the train 1 has actually left the island area, and this could be done by local or remote surveillance known per se. The wayside processor sends in turn a release crossing acknowledgement message 306.

(28) In an alternative embodiment, an auxiliary backup train detection system such as infrared, radar, video, etc. is placed at the crossing in case of communication failures.

(29) The present invention relates also to a railway installation comprising the railway track 2, the level crossing placed along said railway track 2 and the train 1, wherein the wayside processor and the onboard processor are arranged to cooperate so as to implement the method above disclosed.

(30) Clearly, the principle of the invention remaining the same, the embodiments and the details of production can be varied considerably from what has been described and illustrated purely by way of non-limiting example, without departing from the scope of protection of the present invention as defined by the attached claims.