EP0007271B1 - Device for transmitting information by the rails between a railway track and the vehicles running on this track - Google Patents

Description

The present invention relates to a device for transmitting information by rails between a railway track and a set of vehicles traveling in the same direction on this track, along which a plurality of information transmission zones succeed one another.

Railways and mainly those with heavy traffic are usually equipped with a blocking system, in particular by track circuits, which in general uses the running rails as a transmission track.

In modern equipment, it has become necessary to have a device for transmitting information between the track and the vehicles, a device capable of coexisting with the cantonment system, the assembly operating with intrinsic safety, in the railway sense of this term. .

A known solution consists in transmitting information by induction from a cable placed in the track, or along it, but this solution has a certain number of drawbacks: the cost of the cable and the resulting constraints. for track maintenance.

• . - la première provient du fait que les rails de roulement servent de circuit de retour au courant de traction sur les lignes électrifiées et, très souvent, de voie de transmission pour les signaux de cantonnement. Les signaux de tout système de transmission d'informations par les rails doivent donc se superposer à ces courants et signaux existants sans les perturber et pouvoir en être séparés.
• - la deuxième est liée au découpage de la voie en cantons. Il faut que ce découpage n'affecte pas la transmission des informations dont les zones de transmission, lorsque celle-ci s'effectue par zones se succédant le long de la voie, doivent pouvoir être délimitées indépendamment des sections du système de cantonnement.

The use of running rails as a transmission path eliminates these drawbacks, but faces two difficulties:

• . - The first comes from the fact that the running rails serve as a return circuit to the traction current on the electrified lines and, very often, as a transmission channel for the blocking signals. The signals of any information transmission system by rails must therefore be superimposed on these existing currents and signals without disturbing them and able to be separated from them.
• - the second is linked to the division of the track into cantons. This division must not affect the transmission of information, the transmission zones of which, when this takes place in successive zones along the track, must be able to be delimited independently of the sections of the cantonment system.

The device described in British Patent GB 1,451,431 is known and makes it possible to transmit simple local information to the conductor of a train, such as the state of the signals downstream. However, this device is constituted by a track circuit with central supply of alternating current to which are added a second and a third track circuits disposed respectively at each end of each block in order to remove an imprecision as to the precise location of the incompatible train. with security. The transmission of information in this case can only be carried out by means of these second and third track circuits, with a range reduced to around twenty meters upstream of the corresponding turn, while the average length of a block is around two kilometers.

Such a device is therefore incompatible with automatic piloting of trains since it is discontinuous and very little information can thus be transmitted. In addition, such a device is obviously not independent of the sections of the cantonment system, while the information to be transmitted often has nothing in common with these sections.

The device according to the invention overcomes these difficulties because it uses, to transmit the information, an alternative carrier wave modulated in frequency or in amplitude, or both, and of characteristics such as its propagation in the rails n ' is not effected by traction return currents and by blocking signals; moreover, it allows delimitation of its own propagation zones independently of the sections of the cantonment system; finally, it ensures a continuous transmission of information along the way.

• - un générateur de signaux alternatifs à une fréquence déterminée qui constitue la fréquence porteuse des informations à transmettre, cette fréquence étant prise à l'extérieur des bandes de fréquences utilisées dans le système de cantonnement,
• - un modulateur desdits signaux,
• - un organe de commande du modulateur de manière que ces signaux soient modulés en fonction des informations à transmettre,
• - u-_" spire conductrice isolée disposée en forme cadre entre les deux files de rails, près de I'e× mité aval de ladite zone de transmission d'informations,
• - un transformateur adaptateur d'impédance et de séparation de circuits dont le primaire reçoit les signaux modulés et dont le secondaire est relié aux bornes de la spire en forme de cadre,
• - deux circuits résonnants accordés sur la fréquence porteuse, branchés entre les deux files de rails, l'un à l'extrémité aval et l'autre à l'extrémité amont de la zone de transmission d'informations,
• - à bord de chaque véhicule, des moyens de réception accordés sur les fréquences porteuses respectives de zones de transmission d'informations.

This device comprises on the channel, for each information transmission zone:

• - an alternating signal generator at a determined frequency which constitutes the carrier frequency of the information to be transmitted, this frequency being taken outside the frequency bands used in the cantonment system,
• - a modulator of said signals,
• a modulator control member so that these signals are modulated as a function of the information to be transmitted,
• - u- _"insulated conductive winding arranged in frame form between the two lines of rails, near I'e × moth-eaten downstream transmission of said information area,
• - an adapter transformer for impedance and separation of circuits whose primary receives the modulated signals and whose secondary is connected to the terminals of the turn in the form of a frame,
• - two resonant circuits tuned to the carrier frequency, connected between the two rows of rails, one at the downstream end and the other at the upstream end of the information transmission zone,
• - on board each vehicle, reception means tuned to the respective carrier frequencies of information transmission zones.

The information transmission zones which are independent of the sections of the cantonment system are adjacent, so as to ensure continuous transmission of information over the entire length of the track.

• la figure 1 représente le cas d'un dispositif unique de transmission d'informations,
• la figure 2, le cas d'une série de dispositifs semblables, répartis le long de la voie,
• la figure 3, le détail des circuits résonnants entre les files de rails en un point de transition entre deux zones d'émission consécutives,
• la figure 4, un circuit complémentaire de contrôle applicable aux cas précédents.

The invention will be better understood with the aid of a few exemplary embodiments and the accompanying drawings in which:

• FIG. 1 represents the case of a single device for transmitting information,
• FIG. 2, the case of a series of similar devices distributed along the track,
• FIG. 3, the detail of the resonant circuits between the rows of rails at a transition point between two consecutive emission zones,
• FIG. 4, a complementary control circuit applicable to the preceding cases.

FIG. 1 represents a section of rail traffic track comprising only one information transmission zone. The marks 1 and 2 designate the rows of rails. The transmitter circuit 3 of this information, represented in a dashed line frame, is placed on the track near the downstream end of the transmission zone which is delimited by the rails 1 and 2 and by two resonant circuits represented by impedances 4 and 5 at the two ends of this zone. The transmitter circuit 3 is connected to the terminals of an insulated conductive turn 6 arranged in the form of a frame between the two rows of rails 1 and 2, near the impedance 4 located at the downstream end of the emission zone. As an indication, three sections 7, 8, 9 of the cantonment system have been represented. These are, for example, sections covered by three successive track circuits. It can be seen in FIG. 1 that these three sections have limits which do not coincide with those of the information transmission zone delimited by the impedances 4 and 5. The arrow 10 shows the direction of movement of the vehicles on the track.

The transmitter circuit includes a generator 11 of alternating signals serving as a carrier wave for the information to be transmitted and which enters a modulator 12 receiving from a control member 13 the modulating signal necessary for the modulation to be carried out according to the information to be transmitted. . The modulated signal is transmitted to the turn 6 in the form of a frame via a transformer 14 playing the role of impedance adapter and circuit separator.

The frequency of the carrier wave is determined so as to be outside the frequency bands used in the track circuits 7, 8, 9.

For example, carrier frequencies of the order of a kilohertz will be chosen.

Impedances 4 and 5 consist of an inductor in series with a capacitor, so as to produce a resonant circuit whose impedance is minimum for the frequency of the carrier wave of the transmitter 3. These impedances therefore do not leave pass the blocking signals.

The signal emitted in the coil 6 is transmitted by induction to the loop formed by the two rows of rails 1 and 2 and the impedances 4 and 5 acting practically as a short circuit between these rows 1 and 2.

Each vehicle comprises for example as a receiving circuit a sensor tuned to the frequency of the carrier wave of the signals transmitted and receiving them by induction.

FIG. 2 shows three successive emission zones, similar to that of FIG. 1, forming part of a series of emission zones distributed along the track. The numerical references used are two-digit numbers, the tens digit corresponding to the homologous element in FIG. 1 and the units digit representing the serial number of the zone. The first zone has as frequency carrier wave the frequency f1, the second the frequency f2 and the third the frequency f3. These frequencies are considered here as distinct, but they can also be equal. When they are different, the vehicle is fitted with as many sensors on board as there are separate frequencies used.

FIG. 3 shows the detail of the upstream impedance 51 of the first zone which is a resonant circuit tuned to the frequency f1, and of the downstream impedance 42 of the second zone which is a resonant circuit tuned to the frequency f2.

In the case where the frequencies f1, f2, f3 are equal, the diagram in FIG. 3 is reduced to a single resonant circuit tuned to the single carrier frequency used.

When it is necessary to control, to increase the reliability of the device, whether a current flows in the loop 6 of an area, it is checked that an induced current flows in the loop formed by the rows of rails 1 and 2 and the impedances 4 and 5. In this case (see fig. 4), a control circuit is added, consisting of a current transformer 15 whose primary is inserted in series between impedance4 and the line of rails 2 and whose secondary is connected to a current flow detector 16.

In the foregoing, it has been admitted that in each information transmission zone only one carrier wave frequency is used. It is possible, without departing from the scope of the invention, to use several carrier frequencies in the same zone, for example by switching on the turn 6 different transmitter circuits such as 3, each of them corresponding to a particular carrier frequency. In this case, the impedances corresponding to _' 5 and 5 would be constituted by as many resonant circuits in parallel as there are distinct carrier frequencies, each of these frequencies corresponding to a single resonant circuit tuned to it.

Finally, it is possible to superimpose in the same information transmission zone two devices according to the invention, one for each direction of movement of the vehicles, with for example the same carrier frequency.

Claims (1)

1. A device for transmitting data via the rails between a railway track and a vehicle travelling on this track, comprising on the track, for each data transmission zone, a generator (11) of alternating-current signals at a particular frequency constituting the carrier frequency of the signals to be transmitted, a modulator (12) of said alternating-current signals, an element (13) for controlling said modulator in such a way that these alternating-current signals are modulated as a function of the data to be transmitted, an insulated conductive winding (6) arranged in the form of a frame between the two lines (1, 2) of rails near the downstream end of said data transmission zone, an impedance matching device (14) located between said modulator and said winding, and, on board said vehicle, receiving means tuned to said carrier frequency, said device being characterised in that the data transmission zones are adjacent so as to ensure continuous transmission of the data over the entire length of the track, each zone being delimited, independently of the sections of the block system of said track, by two resonant circuits (4, 5) which are tuned to said carrier frequency and which are connected, between the two lines of rails, respectively to the downstream end and to the upstream end of said transmission zone, said carrier frequency being selected outside the frequency bands used in the block system of said track.

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