Method for safe supervision of train integrity and use of on-board units of an automatic train protection system for supervision train integrity

Abstract

A method for safe supervising train integrity includes: (a) acquiring first position data of the first carriage via a first tracking unit which is installed on-board of a first carriage and acquiring second position data of a second carriage via a second tracking unit which is installed on-board of the second carriage, wherein the position data is related to a rail route coordinate system; (b) determining a deviation between a reference value which depends on the length of the train and a position value which depends on position data of at least one of the tracking units; (c) detecting whether train integrity is given by analyzing the deviation; (d) repeating steps a) through c); wherein the tracking units are part of on-board units of an automatic train protection system. Thus a cost-efficient method for supervising train integrity which complies with safety level SIL4 can be realized.

Claims

1. A method for safe supervising train integrity, at SIL4-level, the method comprising the steps of: a) providing a train on a track, the train comprising a first carriage connected directly or indirectly to a second carriage, the first carriage having a first SIL4-proved tracking unit and the second carriage having a second SIL4-proved tracking unit, wherein the first carriage is located at one end of the train and the second carriage is located at the other end of the train, wherein each tracking unit is configured to wirelessly transmit a position data of its respective carriage; b) acquiring a first position data of the first carriage via the first SIL4-proved tracking unit which is installed on-board of the first carriage and acquiring a second position data of the second carriage via the second SIL4-proved tracking unit which is installed on-board of the second carriage, wherein the first and second position data, are related to a rail route coordinate system and are determined via distance measurement along a rail route coordinate system with reference to at least one reference point on a rail route; c) determining a deviation between a reference value which depends on the length of the train and a position value which is determined by subtraction of the first and second rail route coordinate system related position data; d) detecting whether train integrity is given by analyzing the deviation; and e) repeating steps b) through d); wherein tracking units are part of on-board units of an automatic train protection system.

2. The method according to claim 1, wherein the tracking units are additionally used otherwise than for supervising train integrity.

3. The method according to claim 1, wherein balises are used as reference points.

4. The method according to claim 1, wherein first and second position data are transmitted to a control center of the automatic train protection system, in particular to a radio block center of an ETCS-system, wherein the analyzing of the deviation is carried out by means of a central processing unit of the control center.

5. The method according to claim 1, wherein the position data of the first carriage is transmitted to an on-board unit of the second carriage wherein the analyzing of the deviation is carried out by means of the on-board unit of the second carriage and/or that the position data of the second carriage is transmitted to the first carriage, wherein the analyzing of the deviation is carried out by means of the on-board unit of the first carriage.

6. The method according to claim 1, wherein the first carriage is the front carriage, in particular a locomotive, and the second carriage is the rear carriage, in particular a second locomotive, of the train.

7. The method according to claim 1, wherein an alert is initiated in case analyzing of the deviation result is a loss of train integrity.

8. The method according to claim 1, wherein movement authority is denied in case analyzing of the deviation result is a loss of train integrity.

9. The method according to claim 1, wherein the reference value the position value previously determined by having carried out steps b)-d).

Description

BRIEF DESCRIPTIONS OF THE DRAWINGS

(1) The invention is shown in the drawings:

(2) FIG. 1 shows the process of the basic method steps of the inventive method;

(3) FIG. 2 shows an installation for carrying out a first variant of the inventive method, wherein train integrity is determined by an external control center; and

(4) FIG. 3 shows an installation for carrying out a second variant of the inventive method with train based integrity supervision.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(5) FIG. 1 shows the basic method steps of the inventive method. First (front end) position data P1 of a first carriage C1 of a train T and second (rear end) position data P2 of a second carriage C2 of the train T are determined via a first tracking unit T1 and a second tracking unit T2 (see FIG. 2 and FIG. 3). The tracking units T1, T2 are preferably mounted in undividable parts of train T, e.g. locomotives. Any tracking system can be used, e.g.

(6) Doppler radar system, optical fibers, GPS, inertial sensor systems, wheel pulse transducer etc. First position data P1 (also possible: first position data P1 added to a reference value RV=RV(L), e.g. the length L of the train) and/or second position data P2 (also possible: second position data P1 added to a reference value RV, e.g. length L of the train) are transmitted to a processing unit CPU.

(7) A deviation Δ between the reference value RV (here: length L of the train) and a position value PV=PV(P1, P2) (here: the distance D between the first position P1 and the second position P2) is calculated along a rail route of the train, e.g. by subtracting rail route coordinate system related first and second position data P1, P2 and comparing it with the length L of the train T. Instead of second position data P2 only the second tracking unit T2 may also transmit the data in which a tolerable threshold GW is included (e.g. P2+L+GW). In order to get rail route coordinate system related position data it may be necessary to convert the detected (preliminary) position data (e.g. GPS data) in order to relate the position data with a rail route coordinate system.

(8) Analyzing the deviation Δ may comprise checking whether distance D corresponds within a reachable accuracy (±threshold GW) to the length L of the train T (in case offsets of the tracking units T1, T2 to the front/rear end of the train are considered). In case the deviation Δ of the determined distance D and the reference value L exceeds the specific threshold GW loss of integrity is detected.

(9) Alternatively analyzing the deviation Δ may comprise checking whether the following condition is satisfied: P2+L+GW>P1>P2+L−GW.

(10) Another possibility for analyzing the deviation Δ is that both tracking units determine third position data P3 by applying an operator which is specific for the tracking units: P3=K1(P1,L)=K2(P2,L). In case of P3=P2 this results in K1 (P1,L)=P1−L and K2(P2)=P2.

(11) It is also possible that each tracking unit P1, P2 determines expected position data of the respective other tracking unit T1, T2, and transmits the expected position data to the other tracking unit.

(12) In FIG. 2 and FIG. 3 the required components are shown. The train T with front carriage C1 and rear carriage C2 is to be supervised with respect to train integrity. A first on-board-unit OBU1 is provided in the front carriage C1 and a second on-board-unit OBU2 is provided in the rear carriage C2, wherein the first on-board-unit OBU1 is equipped with a first tracking unit T1 and the second on-board-unit OBU2 is equipped with a second tracking unit T2. The tracking units T1, T2 do not necessarily have to be mounted on a locomotive; each kind of rolling stock that allows installation of the tracking units T1, T2 with its sensors is sufficient. A minimalistic solution could be some kind of vehicle with at least one axle and only the tracking unit T1, T2 with its sensors and the according communication system installed on it. In order to realize the inventive train integrity supervision function, a safe communication is required to transmit position data P1, P2.

(13) Although the inventive idea is shown and described in the following based on an ETCS-system, it is not limited to the ETCS-system. In principle the inventive idea can be adapted to all kind of systems including a safe position determination (e.g. ATP-systems) that have a save positioning function implemented within its on-board unit. In the following the examples and semantics are related to the ETCS-standard. Within this standard the train integrity supervision can be realized as follows: The first on-board unit OBU1 (as shown in FIGS. 2 and 3) is in mode “FULL SUPERVISION”. The second on-board unit OBU2 is in mode “SLEEPING”. This guarantees that the second on-board unit OBU2 still performs the positioning function.

(14) FIG. 2 shows a configuration in which supervision is carried out via a control center RBC. Position data P1, P2 are transmitted from the tracking units T1, T2 to a central processing unit CPU of a control center RBC via a mobile network GSM-R of the ETCS-system. According to FIG. 2 GSM-R standard is used as transport layer as this is specified in the UNISIG for the connection between RBC and OBU. Yet, the shown variant also works with other transport layers such as GPRS or UMTS. This variant requires no changes within the on-board units OBU1, OBU2, but some extensions in the control center RBC (supervision, error response). Thus it is compatible to ETCS compliant on-board units. In case of detecting a loss of integrity the control center RBC will give no movement authority any more to the first on-board unit OBU1. This will cause the first on-board unit OBU1 to change into mode “TRIP”, which is a safe state.

(15) FIG. 3 shows a configuration in which train integrity supervision is carried out on the train T directly. For this variant a separate communication channel CH between the two on-board units OBU1, OBU2 is needed. FIG. 2 shows a concept for a wireless connection. Position data P2 of the second tracking unit T2 is transmitted to the first (“FULL SUPERVISION”) on-board unit OBU1 via the communication channel CH.

(16) The protocol used for the transmission channel CH should be compliant to EN50159 for category 3 networks. As such protocols contain timeliness supervision an interruption of the communication will be disclosed in time. In case of either losing the connection between the two on-board units OBU1, OBU2 or discovering a loss of integrity as described above (Δ exceeds threshold GW) the first on-board unit OBU1 changes to mode “SYSTEM FAILURE” in order to reach a safe state. This transmission protocol and the supervision functionality are implemented within the on-board units OBU1, OBU2 and are out of scope of the existing ETCS standard.

(17) Both variants use safe tracking units which may already be used by an automatic train protection system. Position data of the front end and the rear end of the train are determined by using distance measurement along a rail route coordinate system. In order to enhance availability and to ensure high safety level each tracking unit preferably uses a diverse measuring principle by using different types of position sensors. The inventive method enables supervision of train integrity on SIL4-level.