(19)
(11) EP 2 090 491 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Mention of the grant of the patent:
17.08.2011 Bulletin 2011/33

(21) Application number: 08425091.9

(22) Date of filing: 14.02.2008
(51) International Patent Classification (IPC): 
B61L 1/18(2006.01)
B61L 27/00(2006.01)

(54)

System for the detection of trains on railway lines

System zur Detektion von Zügen auf Eisenbahnschienen

Système de détection de trains sur les lignes ferroviaires


(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

(43) Date of publication of application:
19.08.2009 Bulletin 2009/34

(60) Divisional application:
11171102.4

(73) Proprietor: ALSTOM Transport SA
92300 Levallois-Perret (FR)

(72) Inventors:
  • Rizzo, Antonio
    40033 Casalecchio di Reno (BO) (IT)
  • Aisa, Pier Alessandro
    40057 Granarolo Emilia (BO) (IT)

(74) Representative: Karaghiosoff, Giorgio Alessandro 
Studio Karaghiosoff e Frizzi S.r.l. Via F. Baracca 1R 4° piano
17100 Savona
17100 Savona (IT)


(56) References cited: : 
EP-A- 0 878 373
DE-A1- 2 047 147
WO-A-01/96164
   
       
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] The invention relates to a system for detecting trains on railway lines according to the preamble of claim 1

    [0002] Train detection systems are known in the art, as disclosed for example in a prior patent application by the applicant hereof, with publication number EP 1338492. This train detection system is known as track circuit. The track of a railway line is divided into a plurality of segments. Each segment, known as block, has a unit associated therewith, with a transmitter and a receiver designed for alternate connection to each other and to one of the two opposite ends of a corresponding track segment. One signal is injected by the transmitter to one end of the track segment and is received at the opposite end thereof. The transmitted signal has predetermined and appropriately defined frequency, amplitude and coding characteristics wherefore, when a train is present on the track segment, the short circuit between the rails of the track segment caused by the train axles causes a change, particularly a reduction of the signal and allows train detection.

    [0003] Further prior art systems are the so-called axle counters, which include sensors for detecting the axles of a train passing a block.

    [0004] Train detection systems according to the preamble of claim 1 are further known from EP0878 373, De 2047 147 and WO 01/96164

    [0005] In yet other systems the track and the segments are used for communication of messages between the train and the wayside unit and vice versa.

    [0006] All the above prior art systems include electronic operating units, which are basically of hardware type and have a dedicated, special-purpose construction designed for the specific function thereof. For example, concerning the track circuits and as disclosed in the above document with publication number EP 1338492, whose information content is integrated herein by reference, the operating units of the track circuit located at the track, i.e. the trackside or wayside units, include all the sections required for their operation. Particularly, these operating units include track segment interface sections and diagnostic sections, as well as sections for generating the signals to be transmitted and for processing the receive signals and sections for communicating with the central railway traffic management unit, i.e. for transmitting train presence data to said central management unit and for receiving controls from said central management unit.

    [0007] Also, still concerning the track circuits, various construction types are known, which are used in different systems, each involving specific advantages and drawbacks.

    [0008] Thus, for example, in certain track circuits, the joint that connects the receiver and the transmitter to the track segment is controlled by a switch that, depending on the expected train direction, selects the transmitter end of the track segment, and consequently the receiver end, thereby actually defining a signal propagation direction within the track segment. These joints, known as directional joints, allow the use of acoustic or pulse signal coding techniques. The units, that are specially designed to operate in one of the above mentioned modes, cannot operate in other modes wherefore specific dedicated operating units have to be provided for each track circuit type, that have track interfacing heads with a construction specially dedicated to the particular signal coding and transmission mode and especially include the sections for generating the signal to be transmitted and for processing the received signal, which sections are constructed in accordance with the techniques used for coding and decoding or processing said signals for retrieval of train presence information. As a result, any technological modification to a railway line requires either the maintenance of the existing track circuit technology to avoid replacement of the operating units or the replacement of the operating units for adaptation to the new track circuit technologies, the latter option involving the replacement of parts of these operating units that might be used even in combination with the new track circuit technologies.

    [0009] Furthermore, each of the various track circuit types have particular characteristics that make it more or less suitable to use in different operating, wear or degradation conditions of the track segments. In prior art, once a track circuit type has been selected and the operating units dedicated to the selected track circuit type have been installed, the operating mode of the track circuit cannot be changed unless the operating units are also replaced. Such replacement would involve cost drawbacks, and be unfeasible due to time constraints. Nevertheless, in certain cases, for instance in case of oxidative rail degradation, impulsive track circuits should be used, which ensure lower signal attenuation.

    [0010] The operating conditions of the track can also depend on weather. Whole short weather variations might be neglected as transient events, there are climatic zones in which weather effects, such as rain, snow and ice are of seasonal nature and remain for a relatively long period of time, while being still of short duration when considering the time and costs required for shifting to train detection technologies other than those in use and particularly suitable for those weather conditions. It shall be further noted that, at the end of one season, a new season follows, with weather conditions changing again.

    [0011] Yet another drawback of prior art track circuits is that each operating unit is connected independently of the others to the track and the central railway traffic management unit, i.e. the interlocking computers. This requires considerable costs in terms of both materials and installation.

    [0012] The structural rigidity of the modes of the operating units associated with the track circuits is a constraint especially when adapting and maintaining existing lines, but also when making new lines having devices or systems from different manufacturers to be combined together, in which the selection of operation and construction technologies depends on tradition.

    [0013] Track circuit types are also known in which the joints for connection of the transmitter and the receiver of the operating units are of non-directional type and the signal injected into the track circuits propagates in both directions.

    [0014] Here again the operating units are constructed with a structure and an architecture dedicated to their intended tasks and namely to the track interfacing modes.

    [0015] Concerning the track circuits, there exist a number of variants thereof, mostly including:

    Jointless Audio Frequency ,

    Mechanical Joint Low Frequency;

    Mechanical Joint Impulsive.



    [0016] A further drawback concerning all track circuits is that the controlled track sections cannot be longer than about 2 km. Even at such length, track sections require the provision of capacitors arranged along the track segment with the purpose of compensating for signal energy loss.

    [0017] Furthermore, any failure or malfunctioning of an operating unit or a track circuit requires the track circuit and/or the corresponding operating unit to be restored, because the malfunctioning or damage condition triggers a restrictive signal for the corresponding track circuit, i.e. a train presence condition, which signal is transmitted to the traffic management unit. Here, if no replacement operating unit is available, then the corresponding track circuit will be idle, wherefore either it will be forced into a permissive condition or it will always indicate a malfunctioning condition.

    [0018] Concerning the other units, such as the axlecounters and the track to train communication sections, these have substantially the same problems as the track circuits. Furthermore, if several different train detection systems are required to be simultaneously present on the same railway line, i.e. on the same track, e.g. particularly at least one track circuit, at least one axle counter and/or at least one system for exchanging messages from and to the train, a full operating unit is required in prior art for each of these systems, as many operating units being required as there are track segments or blocks.

    [0019] Therefore, considering for example the above mentioned systems, hardware requirements will be three times as great, and this will generate problems both in terms of implementation times and costs and in terms of space requirements for the installation of operating units.

    [0020] Thus, the object of the invention is to improve a train detection system in view of overcoming the above drawbacks without requiring any cost increase, while further simplifying and enhancing the efficiency of the general system architecture, towards a more flexible configuration of the detection methods being used.

    [0021] The invention achieves the above purposes by providing a system according to the preamble of claim 1 further comprising the combination of features of the characterizing part of claim 1.

    [0022] According to the present invention, traditional operating units include, on the one hand, units designed for direct connection to the track and allowing interfacing with the track and transmission and reception of signals having a well determined structure and organization. On the other hand, central processing and control units are provided which also carry out the tasks of prior art operating units, i.e. define the structure of the signals to be transmitted, the detection result by processing the received signals, such as the presence/absence of the train on a given track block and/or the number of axles or even define the content of the messages to be transmitted to the train.

    [0023] While the block interface units, interfacing with the individual track segments, substantially include controllable transmitter and receiver units and are hardware-based, the processing and control units are formed of a combination of hardware and software, including a computer with at least one program stored in its memory, to be executed by such computer, thereby forming a hardware/software operating unit adapted to accomplish the tasks of the processing and control units, required for determining the structure of the signals to be transmitted and the content of any messages to be transmitted, controlling the block interface units to transmit and receive and decode or extract information from the received signals.

    [0024] Therefore, concerning the various train detection methods, the operating tasks involved in these methods are introduced in the processing and control units by the software which changes according to the method being used, whereas the hardware part for software processing and execution is substantially the same and the track interface units are substantially the same and are dedicated to the pitch of signal injection and extraction from and into the track.

    [0025] Communication between the interface heads, i.e. the track interface units and the processing and control units advantageously relies on a communication network, with the interface heads and the processing and control units being connected thereto, each of them being identifiable by a unique ID code.

    [0026] Therefore, thanks to the invention, one processing and control unit hardware configuration and a few specific interface hardware units will allow construction of several different train detection devices, such as a track circuit, an axle counter and/or a track to train communication unit, by simply providing different software programs to be executed by the processing and control unit, each of which software programs causing the processing and control unit to perform the typical tasks of one of the various train detection devices.

    [0027] Particularly, considering the above train detection devices, one hardware configuration may be also provided for the track segment interface units, particularly in the form of signal transmitting and/or receiving units.

    [0028] However, concerning the various track circuit variants, for example, here again the processing and control unit can perform the tasks of said different track circuit variants by executing a corresponding software program.

    [0029] The flexibility of the present system, owing to the implementation of the tasks of train detection devices at software level, the device consisting of the combination of hardware and executable software, and also considering the combination with track interface units, whose tasks are limited to communication with the track and whose configuration is reduced to a minimized number of parts, provides further advantages.

    [0030] An traditional train detection device construction may be provided, for example, in which each track segment comprises at least one interface unit and at least one processing and control unit for each interface unit with a track segment associated therewith.

    [0031] Otherwise, one processing and control unit may be arranged to cooperate with multiple interface units, each associated with one or more blocks, i.e. track segments.

    [0032] In both cases, the processing and control units may execute several different processing and control software programs, each being designed to cause the operation of the processing and control unit according to a different type of detection device and particularly a different type of track circuit.

    [0033] In one practical example, for instance, a track segment has a track circuit associated therewith with pulse signal operation and, in the variant in which each interface unit has its own dedicated processing and control unit, a processing and control program for performing the tasks of an operating unit of a track circuit with pulse signal operation is stored in this processing and control unit. However, the track circuit for another track segment, e.g. an adjacent track segment, may be for example of the low frequency or jointless audio frequency operation type, wherefore a corresponding processing and control program is stored in the processing and control unit, whereby such processing and control unit performs the tasks of a track circuit of the low frequency or jointless audio frequency type.

    [0034] Likewise, the above also applies to the case in which certain track circuits have an additional interface unit which is designed to form, in combination with the processing and control unit and a corresponding software program executed by such unit, an axle counting device or a track to train communication device. When this is possible, instead of providing two or more different track interface units for two or more different detection devices or track circuits, a common interface unit is provided. For injection of signals into a track segment and reception of signals existing on the track segment irrespective of the information to be transmitted or extracted from the signals, identical interface units can be used, the different tasks associated with the type of signal being transmitted, such as a particular coding or modulation of the signal transmitted to the track or a particular processing of the signal received for extracting the requested information being implemented in the processing and control software program executed by the processing and control unit.

    [0035] The above described practical configuration example, in which each interface unit associated with a track segment has a dedicated processing and control unit associated therewith also applies to the variant in which a processing and control unit is associated with or serves multiple interface units, each associated with one of multiple track segments.

    [0036] The above mentioned possibility of switching among several variant track circuit types by simply providing a different processing and control software program to be executed by the processing and control unit, which causes said unit to perform the typical tasks of the selected track circuit type, allows the track circuit to be adapted to the changing conditions of the track segments and possibly to the various conditions of operation of the track circuits, namely to weather conditions.

    [0037] By simply using a different processing and control program, which implements the tasks of a different track circuit type or a different detection device type, a track circuit type and/or a detection device type may be set for each track segment and each weather condition to best suit the specific conditions of the track segments and/or the weather conditions.

    [0038] Thus, for example, track circuits with pulse signal coding should be used in case of highly oxidized tracks, whereas other track circuit types that use different signal coding techniques and different signal frequencies can be more advantageous in case of heavy rains.

    [0039] Advantages especially derive from an implementation of the different types of track circuit or train detection device that essentially consists in the storage and execution of a different processing and control software program, wherefore the system can be realistically and simply adapted to weather conditions, i.e. to short-duration changes of the operating conditions.

    [0040] Particularly, if one processing and control unit is associated with multiple interface units of multiple track segments, then ascertained malfunctioning conditions of certain track circuits may be corrected. With common control of multiple track circuits, an operating fault of a damaged track circuit can be hidden and corrected at the processing and control unit. Hazards are obviously associated with the above arrangement, wherefore a parallel diagnostics system has to be provided to particularly make sure that a false train detection on a track segment is actually caused by malfunctioning of the corresponding track circuit.

    [0041] In this case, a remedy action might consist in merging the damaged track circuit with the adjacent track circuit, and using the train presence or absence indication obtained from the correctly operating track circuit as an indication for the track segment associated with the damaged track circuit.

    [0042] The wrong indication of the malfunctioning track circuit is thus hidden in a safe manner, without causing traffic interruptions either before or during repair of the damaged or malfunctioning track circuit.

    [0043] The invention relates to further characteristics and improvements which form the subject of the dependent claims.

    [0044] The characteristics of the invention and the advantages deriving therefrom will appear more clearly from the following description of a non-limiting embodiment which is illustrated in the accompanying drawings, in which:

    Figure 1 shows a block diagram of the architecture of the system of the present invention.

    Figure 2 shows a block diagram of the architecture of a train detection operating unit of the present invention.

    Figure 3 shows a block diagram of the system in two possible variants of the present invention, in which the left half includes a processing and control unit for each interface unit or head, and the right half includes a processing and control unit that serves multiple interface units or heads.

    Figure 4 shows a more detailed block diagram of the structure of the processing and control unit, according to the variant in which said processing and control unit serves multiple interface heads.

    Figure 5 shows a block diagram of the processing logic section.

    Figure 6 shows a block diagram of the transmitter module of the processing and control logic subsection.

    Figure 7 shows a block diagram of the receiver module of the processing and control logic subsection.

    Figure 8 shows a block diagram of the interface unit or head.

    Figure 9 is a block diagram of the field interface.

    Figures 10 and 11 show the block diagrams of the vital receiver and the AD converter of said field interface.

    Figure 12 shows a block diagram of the structure of a track interface.

    Figure 13 shows a block diagram of the track elements.

    Figure 14 shows a block diagram of a coding example, using a track circuit type with non directional joints using DSSS signal coding.



    [0045] Referring to Figure 1, a system for train detection, i.e. for occupancy detection in a railway line, or the like, and for digital communication with trains running along said railway line comprises at least one track that forms the railway line and is divided into a plurality of successive galvanically insulated segments having a predetermined length, known as blocks, which track segments form, in combination with the control and monitoring subunits 2, 2', 2", an element named track circuit. In Figure 1, track circuits are indicated as Cdb1, Cdb2 and Cdb3. These track circuits use rails to send the signals that allow train detection on the corresponding track segment, and to communicate with a train. Moreover, the signals sent to each track segment may be used to detect any track failures or damages.

    [0046] The system includes a central management and control unit, designated by numeral 1 and indicated as TDM. This management unit generates control signals to execute procedures for detection of a train T and/or procedures for communication with a train on said track and/or to execute diagnostic procedures and transmits them to the control and monitoring subunits 2, 2', 2 " associated with each track block or segment and forming therewith the track circuit Cdb1, Cdb2 and Cdb3. The subunits 2, 2', 2 " are operating units that are designed to execute the procedures for detection of the train T within the associated block, the communication procedures and/or the diagnostic procedures and transmit the control signals, i.e. the detected information about the presence or absence of the train T within the corresponding block and/or about proper communication being established with the train and/or the diagnostic signals relating to the track circuit to the central control and monitoring unit. Each control and monitoring subunit 2 is associated with each corresponding block to form a train detection device in the form of a so-called track circuit Cdb1 Cdb2 and Cdb3, and is connected to the terminal ends thereof by means of a transmitter 3 and a receiver 4. Each subunit 2 and its respective block, i.e. track segment associated therewith are uniquely identified by a predetermined identification code.

    [0047] Namely, the subunits 2, 2', 2" named TDH are of the type designed to operate in insulated double-rail track circuits. In this type of tracks, both rails are mechanically interrupted, and traction power is returned by inductive connections.

    [0048] The control and monitoring subunits 2 are designed for use on two-direction track circuits and, to this end, a signal transmission reversal feature is provided to propagate train detection signals and coded communication signals in the direction opposite to the train running direction.

    [0049] A train is detected by injecting a fixed current signal into each track circuit, i.e. a signal having a fixed current level once it is decoded. The signal transmitted by the transmitter to the track circuit towards the receiver in a direction opposite to the train running direction is received if no train is detected. When a train is present, the rails are shortcircuited by the train itself, and the receiver is not reached by any signal.

    [0050] The control and monitoring subunit 2 can handle (transmit/receive/acknowledge) the following signals:

    codes;

    "fixed frequency" signal, which is used to obtain the occupied/unoccupied function when no code is provided (no path or routing).



    [0051] The track circuit is coded by interrupting a carrier frequency a predetermined number of times per minute (amplitude modulation). This application uses four code types. These types are obtained by using a 50 HZ carrier interrupted 75, 120, 180 or 270 times a minute (the corresponding code is indicated by the number of interruptions per minute).

    [0052] A nine code coding may be also used. In this case, the above mentioned PWM coded signal may be added or superposed to an additional signal derived by an identical PWM modulation of a carrier having a different frequency, i.e. a carrier of 100 to 200 Hz, particularly of 178 Hz.

    [0053] The characteristics of the Fixed Current (CF) train detecting signal must ensure the maintenance of safety conditions even when insulation losses occur at the joints between adjacent track circuits. A track circuit architecture according to an embodiment that will be described in greater detail hereafter includes a transmitter for each track circuit, connected via the operating unit 2, 2', 2" to the central railway traffic management unit 1. A modulation is introduced in the CF signal, which is different between adjacent track circuits and is adapted to ensure safety conditions even when power is transferred from one track circuit to the following one.

    [0054] A possible solution that is also used in prior art, provides different CF signals (4 sets) to be appropriately allocated to track circuits so as to ensure that there is not the same signal on adjacent track circuits. In all sets, the signal is composed of a 50 Hz carrier alternately transmitted in phase and in phase opposition with respect to a hypothetical 50 Hz reference. The sets are differentiated by the time intervals between two successive phase steps. Opposed sections are connected via a 90 ms signal gap, corresponding to 4.5 50 Hz signal periods. By this arrangement, a constant amplitude signal is always provided at the output of a 50Hz tuned pass band filter, ensuring occupancy detection anytime.

    [0055] The above constitutes one of the possible signal coding arrangements for the signals transmitted to the track for train detection using the train detection system of the present invention, which is further illustrated in Figure 2. It shall be noted that this architecture is also used with different types of train detection devices or with different track circuit variants. These variants are differentiated by the techniques they use for coding the transmitted signal and for demodulating the received signal to retrieve train detection information as well as by the techniques for interfacing the operating unit 2, 2', 2" with the track segment which can also use a non directional joint, that does not impart a unique direction of propagation of the signal transmitted over a track segment between a transmitter and a receiver of the operating unit.

    [0056] Therefore, regardless of the specific signal coding technique and of the particular prior art track circuit type as described above, all train detection devices intended in the most general sense as used herein and defined above have the same architecture, particularly as regards the operating unit 2, 2', 2" and suffer from the same drawbacks as described in the general introduction hereto.

    [0057] Figure 2 shows in greater detail the block diagram of the train detection system of the present invention, in which the operating units 2, 2', 2" have a different structure.

    [0058] According to the present invention, the operating unit 2 is composed of several separate units, that is:

    a processing and control unit designated by numeral 10 and named TDM (Train Detection Module);

    a track segment interface unit or head designated by numeral 30 and named TDH (Train Detection Head);

    and a unit for communication between the above two units 10 and 30, which is provided in the form of a digital communication network, such as an Intranet network or the like and is designated by numeral 20 and named TDN (Train Detection Network).



    [0059] As mentioned above, this break-up of the operating units allows the train detection system to have a distributed topology, in which the processing and control units 10 are allocated in a technical room and interact with the track segments via the interface heads 30, i.e. trackside field units, using a typical digital network communication protocol through a communication network designated by numeral 20.

    [0060] This architectural decomposition also causes the tasks carried out by the traditional operating units to be distributed among the various processing and control units 10 over the communication network 20 and the track interface units or heads.

    [0061] The processing and control unit TDM 10 is a section that provides the processing platform of the train detection system. On the one hand, this unit receives information from the interlocking system, i.e. from the central railway traffic management unit 1 using the communication modules PSCOM 110. On the other hand, the processing and control unit generates the information to be transmitted to the track segments and/or to the train using the interface units or heads 30 and the communication network 20. Furthermore, through the network 20, the processing and control unit 10 receives the signals that the interface units or heads 30 detect from the track segments and transmit thereto, and processes them to identify the occupancy state of a specific track segment, i.e. the presence of a train within the specific track segment or to identify other parameters of the railway system or train, such as the number of axles or to identify the content of messages transmitted by the train through the track. The result of such processing is transmitted by the processing and control unit 10 to the railway traffic management unit 1 through a transmission interface 110. Transmission between the processing and control units 10 and the central railway traffic management unit 1 may be of the type known in the art as CAN-BUS, that is widely used in transport systems.

    [0062] As better explained below, the processing and control unit is composed of a hardware and software combination, the hardware part being of substantially general type and adapted to store and execute several different configuration and task implementation programs. Therefore, these programs include the instructions for the hardware part, for the processing and control unit to carry out the above specific tasks, which depend on the type of train detection device being used, i.e. specifically corresponding to a particular type of track circuit or axle counter or track to train communication system. By this arrangement, the processing and control unit exhibit a very high flexibility, and the detection system features may be changed in very short times and at very low costs.

    [0063] As shown in Figure 3, the architecture may be provided in two general variants. One of these variants is shown on the left of Figure 3 and only implies that the traditional prior art operating units are divided into the operating units as mentioned above.

    [0064] Here, at least two interface units or heads 30 are provided for each track segment designed to form a track circuit or a different circuit or device for detection of the train or other operating parameters or conditions of the train and the track segment, and one dedicated processing and control unit 10 is provided for each interface unit or head 30. All the processing and control units 10 communicate via the same communication network 20 with the corresponding track segment interface unit or head. This variant embodiment is defined as Single Track Topology and already provides considerable advantages as compared with prior art architectures.

    [0065] Referring to the right side of Figure 3, the broken-down architecture of the system of the present invention provides a variant topology in which one processing and control unit serves and is thus connected with multiple track segments through the corresponding interface units or heads associated with each track segment.

    [0066] As mentioned above with reference to prior art, each track segment, and hence each track circuit or other device for detection of or communication with the train including the track segment, is identified by a unique identification code, wherefore the processing and control units 10 and the track segment interface units functionally associated therewith can acknowledge and cooperate with each other without interfering with other pairs of processing and control units 10 and interface units 30 within the system.

    [0067] Concerning the interface units, these are dedicated to track management and are located close to the corresponding track segment, or block. The interface units or heads receive control signals from the central or dedicated processing or control unit 10 depending on the selected one of the variants of Figure 3.

    [0068] The controls contain information about the signal type that has to be generated and transmitted to the track segment.

    [0069] Furthermore, the interface units transmit the signals received from the track segment to the processing and control unit 10 irrespective of whether the latter is a central unit or dedicated, as required by the use of a single-track or multi-track topology respectively, illustrated in Figure 3.

    [0070] The connection allowing communication of the interface units 30 with the processing and control unit 10 relies on a digital communication network and shall be deemed an important part of the system architecture, because such communication section provides advantages in terms of system logic and power distribution.

    [0071] Concerning the types of train detection devices that can be used with the train detection system of the present invention, these include:

    jointless audio frequency track circuits;

    low frequency track circuits with mechanical joints

    pulse signal track circuits with mechanical joints axle counters.



    [0072] The above list is provided for illustration purposes only and shall not be deemed to limit the configuration flexibility of the train detection system of the invention.

    [0073] It shall be further noted, for example, that the joints 130 for connection of the track segment interface units may be of directional type, wherefore the track circuit operates like the one known in the prior art and described with reference to Figure 1 in which, depending on the train direction, the signal is injected to either end of the track segment and received at the opposite end of the same track. Otherwise, the track circuit type may include joints 130 with no directional feature, that cause two-way propagation of the signal injected at each block and hence from each interface unit 30 in the track. In this case, the signal transmitted to the track and the signal received therefrom will be coded and decoded in different manners, allowing to precisely and uniquely identify the relation between one component of the received signal and a given track segment.

    [0074] The detailed construction of the processing and control units/s 10 is shown in the block diagram of Figure 4. Referring to Figure 4, the processing and control unit 10 has a processing and control section 210 with a two out of two configuration, also known as 2002. The processing and control section 110 has two processing logic subsections A and B, designated by numerals 310 and 310', which are connected via an internal bus to respective CPUs A and B, designated by numerals 410 and 410'. The two processing sections 310 and 310' also communicate with each other via a communication line, designated as xport. This port is used for synchronization of processes and exchange of vital data and is part of the 2002 platform. Likewise, the two CPUs A and B, designated by numerals 410 and 410', communicate with each other by a serial link line, designated by numeral 510.

    [0075] The processing and control section further includes a power supply subsection 510 and a configuration subsection 610 which stores the configuration parameters of the detection devices that the processing and control unit has to use in combination with corresponding interface units 30.

    [0076] The processing and control section 210 is connected to a communication interface PSCOM, designated by numeral 110, whereby said section 210 communicates with the central railway traffic management unit 1.

    [0077] Furthermore, the processing and control section 210 has network communication interfaces A and B, designated by numerals 710, 710', connected to each of the processing logics 310 and 310'. The processing and control section 210 communicates via the network communication interfaces 710 and 710', through the network 20, with the individual interface units or interface heads 30, each of which is in turn designed to be connected with one of the track segments.

    [0078] The CPUs 410 and 410' operate as a CAN BUS interface with a processing platform 2002 and manage the information generated by the corresponding processing section 310, 310'. These processing sections may be considered as interface drivers for interfacing with the external sections, i.e. the interface heads 30, and for access thereto for control and signal transmission and reception via the connector sections A and B 710 and 710'.

    [0079] The CPUs 410 and 410' communicate with other sections of the processing and control unit 10 using internal bus modules or the CAN BUS.

    [0080] Figure 5 shows in greater detail the structure of the processing sections 310 and 310' that have identical constructions.

    [0081] Each processing section 310, 310'.

    [0082] One of the relevant subsections is the digital signal processing section named DSP and designated by 311. This subsection is the receiving part of the processing engine and has the following tasks:

    Digital processing of signal flows coming from the interface heads 30;

    Generation of test signals to validate the receiving chains of the interface heads 30;

    Mathematical signal processing (RMS measures, FFT, i.e. Fast Fourier Transform analysis), etc.;



    [0083] Determination of the occupancy status of the various track circuits and/or information designed to be detected by a particular train detection device, such as an axle counter or a track to train message communication unit.

    [0084] The DSP subsection 311 may execute various signal processing techniques, in the form of software programs to be executed by said DSP subsection and incorporating specific signal processing or treatment steps according to the processing or treatment methods as selected or required for the type of train detection device to be used. Therefore, a memory 311 is connected to the digital signal processing DSP subsection 311, for storage of the processing software or programs to be executed by said DSP subsection 311.

    [0085] The other section, also programmable, is the configuration subsection 312 which allows configuration of the interface heads managed by the processing and control section 310.

    [0086] Such configuration subsection 312, as well as the digital signal processing DSP subsection 311 communicate via an internal bus with a track to train communication logic subsection, for determining the direction and status of the interface heads, which is designated by numeral 313 and manages the information exchanged with the CPU A and CPU B sections 410, 410' through a communication bus 314. The TDM bus is a bus located in the processing and control unit 10 which manages the communication between modules and subsections, as well as the redundancy of the 2002 architecture and the vital protection of messages.

    [0087] The management of information exchange by the subsection 313 includes management of message transmission from the interface heads 30 to the train, determination of the direction of propagation of the transmitted signal for each interface head 30 when a directional joint is provided as used in prior art and described with reference to the prior art of Figure 1, and such management further includes the status of the track segment relative to each interface head.
    The interface heads 30 communicate with the processing and control sections 310 via the connector subsections 710, 710' which are in turn connected to the processing and control subsection 310 via a connector interface 315.

    [0088] The latter is connected to the subsection 313 via a transmitter module 316 and to the digital signal processing DSP subsection designated by numeral 311 via a receiver module 317.

    [0089] The purpose of the transmitter module 316, which is shown in greater detail in Figure 6 is to generate the train detection signal, e.g. including bit message modulation and phase control, to code the information and the messages of the transmit signal to be transmitted to the interface heads 30, to set the direction of propagation of the transmit signal for each interface head associated with a track segment.

    [0090] Each transmitter module 316 comprises a main logic subsection 160 whereby it communicates with the track to train communication logic subsection 313 for determining the direction and the status of the interface heads. This main logic subsection 160 of the transmitter manages three subsections having different tasks, i.e. message coding, configuration of the transmit signal to be injected into the track signal, and check of the transmit signal to be injected into the track segment.

    [0091] The configuration subsection includes a frequency generator 161 which, in this example, can provide two carriers of different frequencies F1 and F2, giving the symbols bit = 1 and bit = 0 depending on the configuration that has been read by the internal bus of the processing and control module.

    [0092] The module 162 generates a FSK (Frequency Shift Keying) type modulation of the signal to be transmitted to the track segment using as an input the message provided by the bus subsystem TDM 314 and using the carrier signals with the frequencies F1 and F2 generated by the generator 161.

    [0093] On the other hand, the signal checking module 164 determines the amplitude and phase of the signal transmitted to track circuits and the switching module 165 of the track determines the setting of the transmit signal propagation direction from the setting of the switch that sets the signal input end of the track circuit, when the joint of the track segment interface units is of the directional type.

    [0094] The signal at the output of the FSK modulation module 163 is provided to a coding module 166 which adds signal phase and amplitude information to the signal to be transmitted to the track segment, and the signal so coded at the output of the coding module 166 is provided to a network interface 167 wherefrom it is provided to the connection interface subsection 315 for communication with a corresponding interface head 30 through the network 20.

    [0095] Fig. 7 shows an exemplary receiver module 317. The receiver module communicates with the digital signal processing subsection 311 via an internal bus and comprises an interface for communication via said bus, designated by numeral 171. On the other hand, the receiver module 317 communicates with the interface heads 13 through the network 20 and via a network interface 172.

    [0096] On the one hand, the receiver module transmits test signals to a data coder 174. The signals to be transmitted to the track segment are packed with information about the test signals that are used to certify the operation of the interface heads 30.

    [0097] On the other hand, the receiver module receives from the interface head 30 the signals that the latter has received from a corresponding track segment and transmits them, via the network interface 172, to a data decoder 173. Such data decoder processes the signal received from the circuit with information about the recheck signals used to certify the operation of the interface heads 30 and the track occupancy status, whereas a demultiplexing subsection 175 demultiplexes the data from the decoder 173. In the particular example of Figure 6, the demultiplexing operation provides data to the bus interface 171.

    [0098] An exemplary structure for the interface units or heads 30 is shown in Figure 8.

    [0099] The interface unit 30 includes a field interface 301 for communication with the processing and control unit 10, which comprises the means for performing tasks of signal transmission and reception to and from the track segment; a track interface 302 whereby it communicates via track elements 303 with a track segment or block. The track interface 302 comprises the elements required for interconnection with the track segment, such as the tuning unit, wheel detectors, or the like. The track elements include track or rail parts, such as joints, capacitors and other devices, that are directly mounted to the track or the rails.

    [0100] Figure 9 is a block diagram of the field interface 301.

    [0101] A subsection 100 named COM has the purpose of managing transmission and reception and of coding and decoding the data flow of communication with the processing and control unit 10.

    [0102] More in detail, in this example, the data flow is functionally broken down into the following signals:
    • Transmit signals: these are data flows that represent the information used to build or generate the signals to be transmitted or injected to the track segment;
    • Test signals: these signals are transmitted and received from the processing and control unit 10 to certify proper operation of the field interface section 301;
    • Receive signals: these signals come from the track segment and are the track segment response to the transmit signals. These signals are processed by the processing and control unit 10 to retrieve information about the occupancy state of a track segment.


    [0103] The transmit signals are provided to a power driver interface 101 which adapts the signal level and processes the messages from the processing and control unit 10 to control the power amplification subsection 103. This power amplification subsection 103 amplifies AC and pulse signals to ensure compliance thereof with the power requirements for the control of the various track interfaces. Particular advantages can be achieved by the use of a subsection that can dynamically adjust amplitude, frequency and phase of the signal to be transmitted. This section provides a transmit signal portion, named Transmission rechecker, which is designed to be checked by the vital receiver subsection 104. By this arrangement, the transmit signal transmitted to the track segment can be safely checked. The power amplifier 103 receives power from a power section 106 that generates the power amplification signal and converts the power source to be used for the power amplifier.

    [0104] The identification key module 105 contains the unique identification key of the track circuit and has the purpose of checking the identity of the field interface.

    [0105] The vital receiver provides test signals and receive signals to the processing and control unit 10 and communicates with a diagnostic data acquisition section 107.

    [0106] The output of the power amplifier 103 provides the signal to be transmitted to the track segment and to a track switch 108. The latter is also connected to an input of the vital receiver 104, and the receive signal acquired from the track segment is provided to said receiver through it.

    [0107] The input and output of the track switch 108 are connected to the track connection interface section on the left side 200 and the track connection interface section on the right side 200' of the track interface 302.

    [0108] This block is only used when a Signal to Train feature is required, and the associated feature consists in connecting the transmit and receive signals with the right and left ends of the track segment to transmit information to the train in the direction of propagation towards the train, depending on the train direction over the track. The switch 108 is controlled by the processing and control unit 10 using the transmit signal itself.

    [0109] The vital receiver 104 provides vital monitoring of all the parameters required to ensure safe operation of the system. Its main tasks are to acquire and manage the following signals:
    • Receive voltage from the track segment (RX_Track signal);
    • Adapted transmit signal (TX_Recheck signal);
    • Test signal used for safe operation of the receiver (TEST_SIGNALS signal);
    • Identification key (ID_KEY signal);
    • Power supply (POWER SUPPLY RECHECK signal);
    • Time base and reference voltage for A/D and D/A conversion;
    • Diagnostic data (DIAG_DATA signal).


    [0110] The vital receiver 104 has the purpose of managing analog to digital conversion of the signals transmitted and received to and from the track segment.

    [0111] The safe architecture is based on a MooN platform, where M and N are natural numbers and particularly M = N = 2 in the minimum configuration of the present example. In the 2002 configuration, each section, each module and each signal are replicated once.

    [0112] Figure 10 shows the structure of the vital receiver in greater detail.

    [0113] The vital receiver comprises two adders 41, 42. These adders separate the input signals into two individual A/D conversion channels designated by numerals 40 and 40' and particularly separate the signals that come from the track segment TX-TRACK from the check signal TX-RECHECK signal that comes from the power amplifier 103. Also, the adders inject the amplitude test signal by providing an analog addition of the input signal and two test signals (TEST_V1 e TEST_V2) for each A/D conversion channel. An external clock 43 generates an independent time base that is used as a reference frequency for the A/D conversion channels. These channels perform analog/digital conversion of the following signals:
    • RX-TRACK 1,2: signals received from the track segment with the test signal used to certify safe operation of the section (signals TEST_V1 and TEST-V2) superposed thereupon.
    • TX-RECHECK 1,2: signals coming from the power amplifier 104 with the test signal used to certify safe operation of said amplifier (signals TEST_V1 and TEST-V2) superposed thereupon;
    • DIAG_DATA: Diagnostic data acquired by the diagnostic section and designed to be transmitted to the processing and control unit 10. These acquired parameters include, for example: temperature of the field interface devices 301, temperature of the track segment, current consumption, noise measures in- and out-of-band;
    • IDENTIFICATION KEY: - information about the identity of the section (ID_KEY signal);
    • POWER SUPPLY: - Information about the reference power supply values (POWER SUPPLY RECHECK signal);
    • TEST_F1, TEST_F2: signals used to certify proper A/D conversion.


    [0114] The structure of the A/D conversion channels 40 and 40' is shown in Figure 11.

    [0115] The ADC analog to digital conversion section 410 and the multiplexer MUX 411 are controlled by a driver unit 412. The following signals are provided at the input of the multiplexer 411:

    TEST_F: this signal is generated by the section 414 which receives at its input the signal of the external clock 43 and is used to certify the time base of each analog-to-digital conversion 40, 40';

    TEST_PS: this test signal is generated by a power source monitoring section that receives at its input the power source signal;

    TX_RECHECK: this signal is used to certify the signals to be transmitted to the track segment and is generated by the power amplifier 103 of the field interface 301 with the adder 41, 42 superposing thereupon the test signal TEST_V1 or TEST_V2 depending on which of the two digital conversion channels is used. The signal produced by the adder 41, 42 is provided at the input of the multiplexer 411 after being filtered by an antialiasing filter 415;

    RX_TRACK: These signals are received from the track segment through the track elements 303 and the track interface 302, with the adder 41, 42 superposing thereupon the test signal (TEST_V1 or TEST_V2 depending on the A/D channel being used) and are provided at the input of the multiplexer 411 after being filtered by an antialiasing filter 416.



    [0116] A voltage reference signal for the analog-to-digital converter 410 is further provided at the input of the multiplexer. This reference signal is generated by a section 417 that is part of the analog-to-digital converter 410.

    [0117] Finally, diagnostic parameters acquired by the diagnostic subsection 107 are provided to the multiplexer 411.

    [0118] The test signals TEST_V (i.e. TEST_V1 and TEST_V2 a depending on the A/D channel being used) are generated by two DAC sections 418 that are controlled by the processing and control section 10 using the TEST_V signal to certify safe operation of the analog-to-digital conversion process.

    [0119] The analog-to-digital conversion section 410 turns the analog signals from the track segment into digital signals and transmits them through the network interface module 100 and through the network 20 to the processing and control unit 10 once the signals converted into digital form have been coded with the identification key in a section located at the output of the AD converter 410 and designated by numeral 419. Likewise, the test signals TEST_V and TEST_F are generated from TEST signals that come from the processing and control unit 10 in a section 420 specially designed therefor.

    [0120] The track interface module 302 is shown in Figure 13 and consists of the part of the system that is designed to perform the tasks of interconnection with the track in terms of impedance matching and signal level adaptation to the track.

    [0121] The present example has been only described with reference to track circuit features. However, when using axle counters and any other different train detection devices, such as devices for communication between the train and a wayside unit, the structure will be modified according to the peculiarities of these devices which are known in their general structure, wherefore adaptation to the system architecture of the present invention is well known to those of ordinary skill in the art, once adaptation has been described for the track circuit, which is one of prior art train detection devices.

    [0122] The track interface 302 receives the transmit signals TX-SIGNALS, i.e. the signals to be transmitted to the track segment from the field interface 301 and provides them to the track elements 303 as TX_TRACK signals, after submitting these signals to the following steps:

    cable adaptation 500: this step allows impedance matching between the signals provided by the field interface 302 and the cable impedance at which the signals are physically provided to the track to minimize power losses caused by impedance mismatching.

    Galvanic insulation 510: electrical separation between the system and the track and particularly between the track and the field interface and the processing and control unit 10.

    Preshunt 520: preshunt prevention features.

    Joint impedance matching 530;

    Overvoltage protection 540;

    Track connection 550.



    [0123] These steps are also carried out with the signals received from the RX_TRACK track through the track elements 303 and provided at the input of the field interface 302.

    [0124] Concerning the track elements, these are schematically summarized in Figure 14. The track elements physically consist of the components or devices of the system that are located close to the track and are used to balance traction return currents, to compensate for track impedance, to ensure safe operation and to implement electric joints.

    [0125] Electric connection with the track rails is provided by an electric receive and transmit joint 600. This joint is used to electrically separate adjacent track segments and balance the traction return current.

    [0126] Obviously, the rails 610 that carry the track circuit signals and the traction return signal of the train are also to be considered as a track circuit element and hence as a track element.

    [0127] The impedance joint 620 ensures continuity of the return current and ground connection of the rails.

    [0128] The compensation capacity 630 allows equalization of the frequency response of the track and affords longer track segments of the track circuits.

    [0129] Referring to the communication network 20 between the processing and control unit/s 10 and the track segment interfacing unit/s 30, this is a typical digital connection network that can be of various types and operate according to various protocols.

    [0130] Without excluding other types, protocols or architectures of existing and future networks, a star topology is currently preferable for the logic network and possibly also for the power network. Alternatively, the power network may also have a ring topology.

    [0131] In the former topology, power distribution and logic connections will be provided by the same cable. If fiber optic is used for logic connection, a mixed cable will be used, comprising the fiber optic cable and a conduction cable for power distribution. However, if different topologies are used for the logic and the power networks, like in the above variant, two separate cables will be provided and the power network will have a power cable laid along the track. A network structure example from the point of view of communication techniques is the ISO-OSI layer model. The network model is preferably, but without limitation, a client/server network model in which the processing and control units 10 act as servers and the track segment interfacing units act as clients. The communication technique is of the message passing type.

    [0132] The above description only related to the example of track circuits. As explained above, the structure as described herein will not change in its general form with axle counters and other devices for detection of or communication with a train through the track. Changes or integrations may be required as would be obvious to those skilled in the art.

    [0133] It shall be further noted that the above description relates to a specific track circuit example in which, like in Figure 1 showing the prior art, the joint for connection to the track is of the directional type, with signals being always transmitted along the track segments from one end of said segment to the opposite end in a direction opposite to that of the train, so that the transmitted signals propagate towards the train that enters or runs over the track segment.

    [0134] The above disclosure and architecture, as well as the division of the operating units into interface units and processing and control units, both being programmable depending on the system configuration and the type of track circuit and signal coding being used, allow the system as described above to be changed to obtain a non directional track connection type. In this case, the signals transmitted to the track segments propagate in all directions and the received signals include various signal components deriving from the signals transmitted to the track segments.

    [0135] In order to identify the receive signal associated with a transmit signal for a specific track segment, in this case the transmit signals are coded. First, two different frequencies are used for the transmit signals provided to the track. The transmit signals with the two different frequencies are distributed over the track circuits so that signals with different frequencies, corresponding to these two frequencies, are transmitted to two adjacent track segments.

    [0136] Also, the transmit signals with different frequencies are coded, coding being also carried out using two different codes, each of said two codes being only used for coding signals having one of these two frequencies.

    [0137] Signal coding is advantageously a Direct Sequence Spread Spectrum (DSSS) or a Frequency Hopping Spread Spectrum (FHSS) coding, allowing determination of the receive signal component associated with a particular track segment by decoding the receive signals through relation with the signal that is deemed to be associated with the relevant track segment.

    [0138] The block diagram of Figure 15 shows the above principle, the same reference numerals being used therein to denote the same parts as in the previous figures.

    [0139] It will be appreciated that this track circuit variant is obtained, according to the present invention, by only changing the track connection joint from a directional design to a non directional design and by storing a logic processing and control program in the processing and control unit and/or in other programmable units, the execution of which program causes the processing and control unit to operate according to the track circuit variant and a configuration program. This allows the system to be changed as desired by the customer, and as required by the track and weather conditions, by only storing a different processing and control program and without requiring heavy hardware changes.


    Claims

    1. A system for detection of a train, comprising:

    a) a railway line having at least one track, which track is divided into a plurality of successive track segments, known as track blocks,

    b) means (10, 100) for generating and transmitting signals for detection of the train being provided for each of said track segments;

    c) and means (317, 104) for receiving from the track block said detection signals produced by a change of the transmitted signals;

    d) means (311) for processing the detection signals received from the track block to determine the operating or working conditions of the track block based on the changes found in the received signals with respect to the transmitted signals;

    e) means (313) for generating status signals indicative of the operating or working conditions of the track block and for transmitting said status signals to a central railway network control unit (1);

    f) the means (110) for receiving control signals for detection of the train from said central railway network control unit (1);

    g) one or more local interface heads (30) are associated with each track block for interfacing with a corresponding track block, which include: the means (100) for generating and transmitting signals for detection of the train and the means (104) for receiving from the track block said detection signals produced by a change of the detection signals transmitted to the track block;

    h) said local interface heads (30) further include an interface (301) for digital message communication, according to a predetermined communication protocol, with a separate processing and control unit (10);

    i) said processing and control unit (10) includes a digital message communication interface (172) which operates with the same communication protocol as the local interface heads (30);

    j) and said processing and control unit (10) includes hardware 311, 312, 313, 318) in whose memories a processing and control program is stored, to be executed by said hardware and whereby said processing and control unit (10) generates and transmits the control signals to the local interface heads (30) for triggering said local interface heads to generate and transmit predetermined detection signals and for receiving detection signals;

    k) and whereby the processing and control unit (10) processes the detection signals received from the local interface heads (30) to determine the operating or working conditions of the track block based on the changes found in the received signals with respect to the transmitted signals, and generates the status signals indicative of the operating or working conditions of the track block;

    l) whereas said processing and control unit (10) communicates with the central railway network control unit (1) for transmitting thereto said status signals;

    m) wherein the interface heads (30) and/or the track block and the processing and control unit (10) have means (104, 107, 311, 317) for a diagnostic check of their operating conditions,
    characterized in that

    n) the central processing unit has means for integrating two or more track circuits;

    o) the diagnostic means and the means for integrating two or more track circuits are a diagnostic program and a track circuit integrating program which is stored and executed by the processing and control unit (10) or a subsection of said unit (311, 312, 313).


     
    2. A system as claimed in claim 1, characterized in that the interface (301) for communication between the local interface heads (30) and the processing and control unit (10) operate with a network communication protocol, a communication network (20) being provided.
     
    3. A system as claimed in claim 1 or 2, characterized in that multiple parallel processing and control units (10) are provided, which are arranged along a railway line, each controlling and processing the signals of a subset of local interface heads (30) that are connected to corresponding track blocks of a subset of track blocks, whereas each processing and control unit (10) communicates independently with the central railway network control unit (1), each local interface head (30) and/or each track block and each processing and control unit (10) being uniquely identified by an identification code that is associated to the signals for communication between the local interface heads (30) and the corresponding processing and control unit (10) and between said processing and control units (10) and the central railway network control unit (1).
     
    4. A system as claimed in one or more of the preceding claims, characterized in that the local interface heads (30), interfacing with each track block constitute the transmitter unit and the receiver unit of the track circuit, for generating a train detection signal and transmitting said signal to the track block and for receiving said train detection signal from said track block, whereas the processing and control unit (10) is the unit that controls the transmitter and receiver units and the means for processing the detection signals received from the track block for determining the presence or absence of a train on said track block.
     
    5. A system as claimed in claim 4 characterized in that the processing and control unit (10) has means (312, 313, 316) for generating signals for simulated indication of the presence or absence of the train within one or more track blocks.
     
    6. A system as claimed in claim 5, characterized in that means (310, 310'; 311, 312, 313, 318) for integrating two or more track circuits corresponding to two or more adjacent track blocks in a single composite track circuit and, in case of failure of one of said two or more track circuits, the transmitter and receiver units of the faulty track circuits are replaced by at least one transmitter unit and one receiver unit among those of the working circuit/s, said at least one transmitter unit and at least one receiver unit serving the assembly of two or more integrated track circuits.
     


    Ansprüche

    1. System zum Detektieren eines Eisenbahnzugs, umfassend:

    a) eine Bahnstrecke mit mindestens einem Gleis, wobei das Gleis in mehrere aufeinanderfolgende Gleissegmente geteilt ist, die als Gleisblöcke bekannt sind,

    b) für jedes der Gleissegmente bereitgestellte Mittel (10, 100) zum Erzeugen und Senden von Signalen zum Detektieren des Zugs;

    c) und Mittel (317, 104) zum Empfangen der durch eine Änderung der gesendeten Signale erzeugten Detektiersignale von dem Gleisblock;

    d) Mittel (311) zum Verarbeiten der von dem Gleisblock empfangenen Detektiersignale, um auf der Grundlage der in den empfangenen Signalen gegenüber den gesendeten Signalen festgestellten Änderungen die Betriebs- oder Arbeitsbedingungen des Gleisblocks zu ermitteln;

    e) Mittel (313) zum Erzeugen von Statussignalen, welche die Betriebs- oder Arbeitsbedingungen des Gleisblocks angeben, und zum Senden der Statussignale an eine zentrale Bahnnetzleitstelle (1);

    f) die Mittel (110) zum Empfangen von Steuersignalen zum Detektieren des Zugs von der zentralen Bahnnetzleitstelle (1);

    g) einen oder mehrere jedem Gleisblock zugeordnete lokale Schnittstellenköpfe (30) zur Anbindung an einen entsprechenden Gleisblock, welche umfassen: die Mittel (100) zum Erzeugen und Senden von Signalen zum Detektieren des Zugs und die Mittel (104) zum Empfangen der Detektiersignale, die durch eine Änderung der an den Gleisblock gesendeten Detektiersignale erzeugt werden, von dem Gleisblock;

    h) wobei die lokalen Schnittstellenköpfe (30) ferner eine Schnittstelle (301) für die digitale Nachrichtenübertragung gemäß einem vorgegebenen Kommunikationsprotokoll mit einer gesonderten Verarbeitungs- und Steuereinheit (10) umfassen;

    i) wobei die Verarbeitungs- und Steuereinheit (10) eine digitale Nachrichtenübertragungsschnittstelle (172) umfasst, die mit demselben Kommunikationsprotokoll wie die lokalen Schnittstellenköpfe (30) betrieben wird;

    j) und wobei die Verarbeitungs- und Steuereinheit (10) Hardware (311, 312, 313, 318) umfasst, in deren Speicher ein Verarbeitungs-und Steuerprogramm gespeichert ist, um von der Hardware ausgeführt zu werden, und wobei die Verarbeitungs- und Steuereinheit (10) die Steuersignale erzeugt und zu den lokalen Schnittstellenköpfen (30) sendet, zum Anstoßen der lokalen Schnittstellenköpfe, um die vorgegebenen Detektiersignale zu erzeugen und zu senden, und zum Empfangen der Detektiersignale;

    k) und wobei die Verarbeitungs- und Steuereinheit (10) die von den lokalen Schnittstellenköpfen (30) empfangenen Detektiersignale verarbeitet, um auf der Grundlage der in den empfangenen Signalen festgestellten Änderungen gegenüber den gesendeten Signalen die Betriebs- oder Arbeitsbedingungen des Gleisblocks zu ermitteln, und Statussignale erzeugt, welche die Betriebs- oder Arbeitsbedingungen des Gleisblocks angeben;

    l) während die Verarbeitungs- und Steuereinheit (10) mit der zentralen Bahnnetzleitstelle (1) kommuniziert, um die Statussignale an diese zu senden;

    m) wobei die Schnittstellenköpfe (30) und/oder der Gleisblock und die Verarbeitungs- und Steuereinheit (10) Mittel (104, 107, 311, 317) für eine Diagnoseprüfung ihrer Betriebsbedingungen aufweisen,
    dadurch gekennzeichnet, dass

    n) die zentrale Verarbeitungseinheit Mittel zum Integrieren von zwei oder mehr Gleiskreisen aufweist;

    o) die Diagnosemittel und die Mittel zum Integrieren von zwei oder mehr Gleiskreisen ein Diagnoseprogramm und ein Gleiskreis-Integrierprogramm sind, welche von der Verarbeitungs- und Steuereinheit (10) oder einem Unterabschnitt dieser Einheit (311, 312, 313) gespeichert und ausgeführt werden.


     
    2. System nach Anspruch 1, dadurch gekennzeichnet, dass die Schnittstelle (301) für die Kommunikation zwischen den lokalen Schnittstellenköpfen (30) und der Verarbeitungs- und Steuereinheit (10) mit einem Netzkommunikationsprotokoll betrieben wird, wobei ein Kommunikationsnetz (20) vorgesehen ist.
     
    3. System nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass mehrere parallele Verarbeitungsund Steuereinheiten (10) vorgesehen sind, welche entlang einer Bahnstrecke angeordnet sind, wobei jede die Signale einer Teilmenge von lokalen Schnittstellenköpfen (30) steuert und verarbeitet, welche mit entsprechenden Gleisblöcken einer Teilmenge von Gleisblöcken verbunden sind, während jede Verarbeitungs- und Steuereinheit (10) unabhängig mit der zentralen Bahnnetzleitstelle (1) kommuniziert, wobei jeder lokale Schnittstellenkopf (30) und/oder Gleisblock und jede Verarbeitungs- und Steuereinheit (10) durch einen Identifizierungscode eindeutig identifiziert ist, welcher den Signalen für die Kommunikation zwischen den lokalen Schnittstellenköpfen (30) und der entsprechenden Verarbeitungs- und Steuereinheit (10) und zwischen den verarbeitungs- und Steuereinheiten (10) und der zentralen Bahnnetzleitstelle (1) zugeordnet ist.
     
    4. System nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die lokalen Schnittstellenköpfe (30), die an jeden Gleisblock angebunden sind, die Sendereinheit und die Empfängereinheit des Gleiskreises bilden, zum Erzeugen eines Zugdetektiersignals und zum Senden des Signals an den Gleisblock und zum Empfangen des Zugdetektiersignals von dem Gleisblock, während die Verarbeitungs- und Steuereinheit (10) die Einheit ist, welche die Sender- und die Empfängereinheiten und die Mittel zum Verarbeiten der Detektiersignale, die von dem Gleisblock empfangen werden, steuert, zum Ermitteln des Vorhandenseins oder Nichtvorhandenseins eines Zugs auf dem Gleisblock.
     
    5. System nach Anspruch 4, dadurch gekennzeichnet, dass die Verarbeitungs- und Steuereinheit (10) Mittel (312, 313, 316) zum Erzeugen von Signalen für die simulierte Anzeige des Vorhandenseins oder Nichtvorhandenseins des Zugs innerhalb eines oder mehrerer Gleisblöcke aufweist.
     
    6. System nach Anspruch 5, dadurch gekennzeichnet, dass Mittel (310, 310'; 311, 312, 313, 318) zum Integrieren von zwei oder mehreren Gleiskreisen, die zwei oder mehreren benachbarten Gleisblöcken entsprechen, zu einem einzigen zusammengesetzten Gleiskreis und, beim Ausfall von einem der zwei oder mehr Gleiskreise, die Sender- und Empfängereinheiten der gestörten Gleiskreise durch mindestens eine Sendereinheit und eine Empfängereinheit von denen des/der funktionierenden Kreise(s) ersetzt werden, wobei die mindestens eine Sendereinheit und die mindestens eine Empfängereinheit die Gruppe aus zwei oder mehreren integrierten Gleiskreisen bedienen.
     


    Revendications

    1. Système de détection de train, comprenant:

    a) une ligne ferroviaire présentant au moins un rail de voie ferrée, lequel rail de voie ferrée est divisé en une pluralité de segments de rail de voie ferrée successifs, appelés blocs de rail de voie ferrée;

    b) un moyen (10, 100) pour générer et transmettre des signaux en vue de la détection du train, fournis pour chacun desdits segments de rail de voie ferrée; et

    c) un moyen (317, 104) pour recevoir, en provenance du bloc de rail de voie ferrée, lesdits signaux de détection générés sous l'effet d'une modification des signaux émis;

    d) un moyen (311) pour traiter les signaux de détection reçus à partir du bloc de rail de voie ferrée en vue de déterminer l'état de fonctionnement ou d'exploitation du bloc de rail de voie ferrée sur la base des modifications rencontrées dans les signaux reçus relativement aux signaux émis;

    e) un moyen (313) pour générer des signaux d'état indiquant l'état de fonctionnement ou d'exploitation du bloc de rail de voie ferrée et pour transmettre lesdits signaux d'état à une unité centrale de commande de réseau ferroviaire (1);

    f) un moyen (110) pour recevoir les signaux de commande en vue de la détection du train à partir de ladite unité centrale de commande de réseau ferroviaire (1);

    g) une ou plusieurs têtes d'interface locales (30) associées à chaque bloc de rail de voie ferrée en vue d'un interfaçage avec un bloc de rail de voie ferrée correspondant, et comportant: le moyen (100) pour générer et transmettre les signaux en vue de la détection du train et le moyen (104) pour recevoir, à partir du bloc de rail de voie ferrée, lesdits signaux de détection générés sous l'effet d'une modification des signaux de détection transmis au bloc de rail de voie ferrée;

    h) dans lequel lesdites têtes d'interface locales (30) comprennent en outre une interface (301) pour la communication de messages numériques, selon un protocole de communication prédéterminé, avec une unité de commande et de traitement distincte (10);

    i) dans lequel ladite unité de commande et de traitement (10) comprend une interface de communication de messages numériques (172) qui fonctionne avec le même protocole de communication que les têtes d'interface locales (30); et

    j) dans lequel ladite unité de commande et de traitement (10) comprend des équipements (311, 312, 313, 318) dont les mémoires stockent un programme de commande et de traitement, à exécuter par lesdits équipements, et moyennant quoi ladite unité de commande et de traitement (10) génère et transmet les signaux de commande aux têtes d'interface locales (30) pour amener lesdites têtes d'interface locales à générer et à transmettre des signaux de détection prédéterminés et à recevoir les signaux de détection; et

    k) moyennant quoi l'unité de commande et de traitement (10) traite les signaux de détection reçus à partir des têtes d'interface locales (30) afin de déterminer l'état de fonctionnement ou d'exploitation du bloc de rail de voie ferrée sur la base des modifications rencontrées dans les signaux reçus relativement aux signaux émis, et génère les signaux d'état indiquant étant de fonctionnement ou d'exploitation du bloc de rail de voie ferrée,

    l) alors que l'unité de commande et de traitement (10) communique avec l'unité centrale de commande de réseau ferroviaire (1) pour lui transmettre lesdits signaux d'état;

    m) dans lequel les têtes d'interface (30) et/ou le bloc de rail de voie ferrée et l'unité de commande et de traitement (10) présentent un moyen (104, 107, 311, 317) pour réaliser un contrôle de diagnostic de leurs états de fonctionnement; caractérisé en ce que:

    n) l'unité de traitement centrale présente un moyen pour intégrer deux circuits de rail de voie ferrée ou plus; et

    o) le moyen de diagnostic et le moyen d'intégration de deux circuits de rail de voie ferrée ou plus représentent un programme de diagnostic est un programme d'intégration de circuits de rail de voie ferrée, lesquels sont stockés et exécutés par l'unité de commande et de traitement (10) ou une sous-section de ladite unité (311, 312, 313).


     
    2. Système selon la revendication 1, caractérisé en ce que l'interface (301) pour la communication entre les têtes d'interface locales (30) et l'unité de commande et de traitement (10) utilise un protocole de communication réseau, et en ce qu'un réseau de communication (20) est fourni.
     
    3. Système selon la revendication 1 ou 2, caractérisé en ce que de multiples unités de commande et de traitement parallèles (10) sont fournies, lesquelles sont agencées le long d'une ligne ferroviaire, et commandent et traitent chacune les signaux d'un sous-ensemble de têtes d'interface locales (30) qui sont connectées à des blocs de rail de voie ferrée correspondants d'un sous-ensemble de blocs de rail de voie ferrée, tandis que chaque unité de commande et de traitement (10) communique de façon indépendante avec l'unité centrale de commande de réseau ferroviaire (1), chaque tête d'interface locale (30) et/ou chaque bloc de rail de voie ferrée est chaque unité de commande et de traitement (10) étant identifié(e) de manière unique par un code d'identification qui est associé aux signaux pour la communication entre les têtes d'interface locales (30) et l'unité de commande et de traitement correspondante (10) et entre ladite unité de commande et de traitements (10) et l'unité centrale de commande de réseau ferroviaire (1).
     
    4. Système selon l'une quelconque ou plusieurs des revendications précédentes, caractérisé en ce que les têtes d'interface locales (30), lesquelles s'interfacent avec chaque bloc de rail de voie ferrée, constituent l'unité d'émetteur et l'unité de récepteur du circuit de rails de voie ferrée, pour générer un signal de détection de train et transmettre ledit signal au bloc de rail de voie ferrée, et pour recevoir ledit signal de détection de train en provenance dudit bloc de rail de voie ferrée, alors que l'unité de commande et de traitement (10) est l'unité qui commande les unités de récepteur et d'émetteur et le moyen de traitement des signaux de détection reçus à partir du bloc de rail de voie ferrée, en vue de déterminer la présence ou l'absence d'un train sur ledit bloc de rail de voie ferrée.
     
    5. Système selon la revendication 4, caractérisé en ce que l'unité de commande et de traitement (10) comporte un moyen (312, 313, 316) pour générer des signaux en vue d'indiquer par simulation la présence ou l'absence du train sur un ou plusieurs blocs de rail de voie ferrée.
     
    6. Système selon la revendication 5, caractérisé par un moyen (310, 310'; 311, 312, 313, 318) pour intégrer deux circuits de rail de voie ferrée ou plus correspondant à deux blocs de rail de voie ferrée adjacents ou plus dans un circuit de rails de voie ferrée composite unique et, caractérisé en ce que, en cas de défaillance d'un desdits deux circuits de rails de voie ferrée ou plus, les unités de récepteur et d'émetteur des circuits de rails de voie ferrée défectueux sont remplacées par au moins une unité d'émetteur et une unité de récepteur parmi celles du ou des circuits opérationnels, ladite au moins une unité d'émetteur et ladite au moins une unité de récepteur desservant le montage de deux circuits de rails de voie ferrée intégrés ou plus.
     




    Drawing
































    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description