EP2216230A1

EP2216230A1 - Method for releasing a route after cancellation of the route by an interlocking

Info

Publication number: EP2216230A1
Application number: EP09001487A
Authority: EP
Inventors: Marina Kresse; Nader Nayeri; Karl Schnabl; Georg Hemzal
Original assignee: Thales Deutschland GmbH; Thales Deutschland Holding GmbH
Current assignee: GTS Deutschland GmbH
Priority date: 2009-02-04
Filing date: 2009-02-04
Publication date: 2010-08-11

Abstract

A method for releasing a route (B-C) after cancellation of the route (B-C) by an interlocking (IL) comprises the following steps:
sending a cancellation message (10) from the interlocking (IL) to a radio block center, RBC, for cancelling the route (B-C);
checking by the RBC whether or not a train (3) under RBC responsibility is affected by the route cancellation;
sending a first confirmation message (11) from the RBC to the interlocking (IL) indicating whether or not a train (3) under RBC responsibility is affected by the route cancellation; and
if a train (3) under RBC responsibility is affected by the route cancellation,
- sending a command (12) from the RBC to an on-board unit, OBU, of the affected train (3) for shortening a Movement Authority, MA, of the OBU,
- after receiving an acknowledgement message (13) from the OBU, sending a second confirmation message (14) from the RBC to the interlocking (IL) for allowing the route release; and
- after receiving both the first and second confirmation messages (11, 14), releasing the route (B-C) by the interlocking (IL).

Description

Background of the invention

The invention relates to a method for releasing a route after cancellation of the route by an interlocking, and a computer product comprising code means adapted for performing all steps of this method.
In "European Train Control System" (ETCS) - L2 (level 2) & L3 (level 3), following hazard has to be avoided to reach the required safety level of an "European Train Control System" (ERTMS): A train with cab signalling moves on a released route after route cancellation. Derailment and collision are possible consequences. The cause for the mentioned hazard is a route cancellation and release by the system responsible for route protection without any confirmation from ERTMS system about an affected train and successful shortening of the "Movement Authority" (MA) on-board. The system responsible for the route protection will be called "Interlocking System" (IL) in the following, because the proposed procedure relates to trackside equipment where the function of route protection and train protection are distributed in different systems resp. units.
In ETCS systems, the interlocking system allows the route release after the cancellation:

a) either authorized by the operator with a command automatically registered (applied in Germany). But human error (e.g. selecting wrong route, violate operational rules, insufficient knowledge about successful shortening of MA) may lead to this hazard.
b) or automatically after expiration of a timer (applied mostly abroad). The problem is that the timer shall be long from safety point of view and as short as possible from operational point of view. That leads to the conflict to find an optimum between safety and operation.

These two measures a) and b) are operationally obstructive and unnecessarily time consuming for the railway operation, due to the following reasons:

The train has to reach standstill before the route cancellation is allowed to be performed by an operational rule in both cases a and b).
The timer has to expire (in case b).
The train has to be deactivated and activated again, if the driver is not able to see a shortening of the movement authority on the display (in case a).

The measures a) and b) do not solve the hazard completely and systematically. The hazard can still occur with a remaining probability, in case of

a) human errors: The operator releases the route without guarantee of shortening of the movement authority stored on-board.
The driver can make a mistake and forget to take appropriated measures for deleting the movement authority.
b) interruptions on RBC-IL ("Radio Block Center of IL") and/or RBC-on-board interfaces, which inhibit the shortening of movement authority in time.

Object of the invention

It is therefore the object of the invention to completely avoid the hazard that a train with cab signalling moves on a released route after route cancellation.

Short description of the invention

This object is achieved, in accordance with the invention, by a method for releasing a route after cancellation of the route by an interlocking, comprising the following steps:

sending a cancellation message from the interlocking to a radio block center, RBC, for cancelling the route;
checking by the RBC whether or not a train under RBC responsibility is affected by the route cancellation;
sending a first confirmation message from the radio block center to the interlocking indicating whether or not a train under RBC responsibility is affected by the route cancellation; and
if a train under RBC responsibility is affected by the route cancellation,
- sending a command from the RBC to an onboard unit, OBU, of the affected train for shortening a Movement Authority, MA, of the OBU,
- after receiving an acknowledgement message from the OBU, sending a second confirmation message from the RBC to the interlocking for allowing the route release; and
- after receiving both the first and second confirmation messages, releasing the route by the interlocking.

According to the invention, two confirmation messages are sent from RBC to the IL. The first confirmation message indicates, if a train under RBC responsibility is affected. (A train is under RBC responsibility, if the train follows a movement authority or has stored a movement authority which will be used after switching under responsibility of the continuous train protection system). If yes, the IL has to wait until a second confirmation. If no train with cab signalling is affected, the IL can continue with the same measures as for other train protection systems (e.g. timer has expired). In case of disturbance of the interface between RBC and IL a timer-based solution can be applied, which ensures that the train comes to standstill before the route is released.
The second confirmation message indicates that the movement authority is successfully shortened on-board, after an acknowledgement from on-board is received by RBC. The IL is not allowed to release the route before the two confirmation messages are received from RBC.
This confirmation procedure on IL-RBC interface systematically solves the hazard and is completely independent from track topology and operational situations. Operational obstruction occurs only in cases of degraded situations or failures of the involved components, but not during normal operation. The method according to the invention is a systematic technical solution without any impact on the existing on-board units. This is a high economic advantage for railway companies, because the high number of trains can be used without any changes. Moreover, the solution remedies defects in the currently standardized UNISIG SRS ("Union Industry of Signalling"), which does not provide sufficient measures to RBC to handle the shortening of movement authority during the entry to ETCS-L2/L3.
The invention is applicable not only to ETCS L2&L3, but to all systems using a continuous train protection with cab signalling.

Preferred embodiments of the invention

In a preferred embodiment of the invention, the second confirmation message is sent from the RBC to the interlocking not until the RBC has received a standstill message from the OBU of the affected train, i.e. not until standstill of the train.
Finally, the invention relates to a computer product which comprises code means adapted for performing all steps of the above method.
Further advantages can be extracted from the description and the enclosed drawing. The features mentioned above and below can be used in accordance with the invention either individually or collectively in any combination. The embodiments mentioned are not to be understood as exhaustive enumeration but rather have exemplary character for the description of the invention.

Drawing

The invention is shown in the drawing, in which:

Fig. 1: schematically shows a "European Train Control System" (ETCS) with a train under RBC responsibility and the messages sent between the interlocking, the RBC and the train according to the invention, when a route after cancellation of the route is released by the interlocking; and
Fig. 2: shows the steps of a method for releasing a route after cancellation of the route by an interlocking, according to the invention.

Fig. 1 shows schematically a "European Train Control System" (ETCS) 1 comprising at the trackside an interlocking IL, balises or loops (not shown) laid in the track 2 and a RBC ("radio block center") connected to the interlocking IL. A train 3 under RBC responsibility comprises an ETCS on-board unit OBU for communicating with the RBC via GSM-R (Global System for Mobile Communications - Rail). A train is under RBC responsibility, if the train follows a movement authority (MA) or has stored a movement authority which will be used after switching under responsibility of the continuous train protection system.
In Fig. 1, the train 3 is on the route from A over B to C. If the route B to C is to be canceled and then released by the interlocking IL e.g. for another train, the following steps shown in Fig. 2 are carried out.
At time t1, a cancellation message 10 is sent from the interlocking IL to the RBC for cancelling the route B to C (step S1). The RBC checks whether or not a train under RBC responsibility is affected by the route cancellation (step S2) and, if yes like in the case under consideration, sends a first confirmation message 11 to the interlocking IL indicating that a train under RBC responsibility, i.e. train 3, is affected by the route cancellation (step S3). Then, the RBC sends a command 12 to the OBU of the train 3 for shortening a "Movement Authority", MA, of the OBU (step S4), in oder to bring the train 3 to a standstill (emergency stop). The OBU acknowledges the reception of the command 12 by sending an acknowledgement message 13 to the RBC (step S5). After receiving the acknowledgement message 13, the RBC sends a second confirmation message 14 to the interlocking IL for allowing the route release (step S6). After the interlocking IL has received both the first and second confirmation messages 11, 14 (YES in step S7), the interlocking IL is allowed to release the route B-C e.g. for another train (step S8). Optionally, the second confirmation message 14 is sent from the RBC to the interlocking IL not until the RBC has received a standstill message 15 from the OBU of the affected train 3, i.e. not until standstill of the train 3 at time t2.
If no train under RBC responsibility is affected (NO in step 2), the interlocking IL can continue with the same measures (step S9) as for other train protection systems (e.g. timer has expired). In case of disturbance of the interface between RBC and interlocking IL, a timer-based solution can be applied, which ensures that a train comes to standstill before the route is released.

Claims

Method for releasing a route (B-C) after cancellation of the route (B-C) by an interlocking (IL), comprising the following steps:
sending a cancellation message (10) from the interlocking (IL) to a radio block center, RBC, for cancelling the route (B-C);

checking by the RBC whether or not a train (3) under RBC responsibility is affected by the route cancellation;

sending a first confirmation message (11) from the RBC to the interlocking (IL) indicating whether or not a train (3) under RBC responsibility is affected by the route cancellation; and

if a train (3) under RBC responsibility is affected by the route cancellation,
- sending a command (12) from the RBC to an on-board unit, OBU, of the affected train (3) for shortening a Movement Authority, MA, of the OBU,

- after receiving an acknowledgement message (13) from the OBU, sending a second confirmation message (14) from the RBC to the interlocking (IL) for allowing the route release; and

- after receiving both the first and second confirmation messages (11, 14), releasing the route (B-C) by the interlocking (IL).
Method according to claim 1, characterized in that the second confirmation message (14) is sent from the RBC to the interlocking (IL) not until the RBC has received a standstill message (15) from the OBU of the affected train (3).
Computer product comprising code means adapted for performing all steps of the method according to claim 1 or 2.