GB2237959A

GB2237959A - Transmission system for rail vehicles

Info

Publication number: GB2237959A
Application number: GB9018461A
Authority: GB
Inventors: Walter Jaeger
Original assignee: ADCOUNT Ltd
Current assignee: ADCOUNT Ltd
Priority date: 1989-09-01
Filing date: 1990-08-22
Publication date: 1991-05-15
Anticipated expiration: 2010-08-22
Also published as: GB9018461D0; ES2024922A6; DE4027186A1; FR2651471B1; IT1241780B; GB2237959B; IT9009476A1; IT9009476A0; FR2651471A1

Abstract

To transmit information and/or commands from one rail vehicle (1) to the next (3) of the same train assembly, a transmission system is used which is designed such that the data items which are to be transmitted modulate, in coded form, a microwave transmitter (6) of the first rail vehicle (1), and the radiation from the said transmitter is transmitted by a transmitting antenna (8) of the latter in the direction of the receiving antenna (9) of a microwave receiver (7) of the second rail vehicle (3). The radiation received by the microwave receiver (7) of the second rail vehicle is forwarded and if necessary is demodulated or is demodulated and decoded. <IMAGE>

Description

1 - 4 1 1 -- _ 1. ', A TRANSMISSION SYSTEM FOR RAIL VEHICLES The invention

relates to a transmission system for the transmission of information and/or commands from at least one rail vehicle to the next of the same train assembly.

In the context of rail vehicles it is known to use electromechanical plug couplings to transmit information and/or commands. In the case of nonautomatic couplings, as are conventionally used in normal railway traffic, such plug couplings must be coupled and decoupled manually, which is extremely complicated and often unreliable.

In the future railways will require the transmission of a considerable number of signals, such as for example commands and information. By using a coded high frequency carrier all the above-mentioned signals could be transmitted via one sipgle line, for example with a band width of 70 MHz. An electromechanical coupling of two such high frequency lines between two consecutive rail vehicles suitable both for the extreme roughness of railway operation and the security demanded in signalling technology would be too costly in practice and does not permit coupling to be carried out prior to the final mechanical coupling of the rail vehicles.

The aim of the present invention is, in particular, to provide a transmission system which does not entail the above-mentioned disadvantages.

This aim is fulfilled in a transmission system of the type referred to in the introduction, in accordance with the invention, as described in the characterising part of Patent Claim 1.

To achieve signalling security it is expedient to monitor the transmission path in that the data items which are to be transmitted are fed back, unchanged in their contents, from the last rail vehicle of the train assembly to the first rail vehicle and are checked for 1 i 2 accuracy, and for this purpose it is also advantageous for at least two transmission paths extending in parallel with each other to be provided in each of the rail vehicles, in the longitudinal direction thereof, that the ends of the said transmission paths each lead to a transmitting- receiving antenna, and that transmission paths are preferably connected to one or more transmitting-receiving unit(s).

As, during use, the rail vehicles are moved in relation to one another both in the vertical and the horizontal directions, it is expedient for the radiation patterns of the antennae of the microwave transmitter and the microwave receiver to each possess a divergent characteristic and for the antennae to be designed as microstrip antennae.

To prevent cross-talk from transmitters which do not form part of the train assembly by screening by the metal masses, it is advantageous for the antennae of the receiver and transmitter to be arranged in the plane of symmetry of the rail vehicle at the front end thereof, preferably in the vicinity of the vehicle roof.

In order that undesired reflections between the antenna groups of two consecutive, coupled rail vehicles can be weakened to a level which is no longer disturbing, it is advantageous for the antennae of the microwave transmitter and the microwave receiver to be designed as microstrip antennae and for at least the near surrounding field of the antennae, preferably in a region surrounding these antennae whose breadth at least corresponds to the wave length being used, to be designed to absorb the radiation which is used.

As the distance between the rail vehicles to be coupled will always be less than 1 metre, it can be advantageous for the antennae to be in the form of magnet coils which generate a magnetic alternating field but do not generate high frequency which is radiated over long distances.

3

Claims

Additional advantageous further developments of the invention are the

subjects of Claims 3, 4, 6, 7 and 12.

In the following, the invention will be explained in detail in the form of an example, making reference to the drawing in which:

Fig. 1 is a schematic diagram of the transmission system corresponding to the invention in a train assembly linked by signals; Fig. 2 is a lateral view of one single rail vehicle of the train assembly illustrated in Fig. 1, showing the antenna arrangement; Fig. 3 is a schematic plan view of the antenna group of rail vehicle; Fig. 4 is a block diagram of a transmitting- and receiving unit; Fig. 5 is the component diagram of the transmitting- and receiving unit illustrated in Fig. 3, with the antenna group, and Fig. 6 is an illustration of another exemplary embodiment of a transmitting- and receiving unit connected to coil antennae.

The train assembly illustrated in Figure 1 comprises the two driving units 1 and 2 and the carriage 3 coupled between them.

As can be seen from this Figure 1, the driving units 1 and 2 are each provided with a data processing unit 4 and the carriages coupled between them are each provided with a data processing unit 5. The data processing units 4 and 5 are each electrically connected to the desired signal receivers, for example TVreceivers, and signal emitting units, e.g. a telephone.

On their other side the data processing units 4 and 5 are electrically connected to the transmitters 6 and receivers 7 which they are assigned, and the latter are electrically connected to the transmitting- and 4 receiving antennae 8 and 9 respectively, which are in each case combined to form antenna groups.

To facilitate signalling security two closed-loop signal circuits are provided so that at all times and at all locations the response can be monitored.

Naturally in such a transmission system it is also possible, when an appropriately designed, stationery opposite station 12 (Fig. 1) is provided, to transmit information and/or commands between the train assembly and a ground station.

If necessary, for this purpose antennae operating in the downwards direction towards the region of the rails can also be arranged on the train assembly.

As can be seen from Figure 2, the antenna group 10 comprising transmitting and receiving antennae 8 and 9 respectively is arranged in the axis of symmetry of the carriage 3 at the front end thereof, in the vicinity of the roof. With such an arrangement of the antenna groups 10, the assigned carriages 3 serve to screen external interference influences.

As can be seen from Figure 3, the antenna groups 10 are provided with microstrip antennae 8 and 9. This antenna group 10 is constructed for a transmission system which has been duplicated for security reasons. In this case the near surrounding field 11 of the antennae 8 and 9, in a region surrounding these antennae whose breadth at least corresponds to the wave length being used, is designed to absorb the radiation which is used.

As can be seen from the block diagram in Figure 4, in the transmitter 6 the coded signal occurring at 2 Mbit/sec is steepened in gradient by means of the integrated circuit RS 421, amplified in the integrated circuit TTLj, and used as supply voltage for the crystal oscillator SC. The 10 GHz-oscillation formed in this way is refined in the filter F, and fed to the transmitting antenna 8. The corresponding component diagram is shown in Figure 5.

The signal response is received in the antenna 9, refined in the filter F2 and rectified in the rectifier G1. In the filter F3 the 70 MHz- component is filtered out, steepened in gradient in the integrated circuit RS 421 and amplified in the integrated circuit TTL2. The corresponding component diagram is likewise shown in Figure 5.

As can be seen from the block diagram of another exemplary embodiment, shown in Figure 6, a signal occurring at 2 Mbit/sec is used to modulate a 20 MHztransmitter 6'. The latter acts on a magnet coil 8' which serves as transmitting antenna.

The magnet coil 9' which serves as receiving antenna is itself connected to a receiver 7' and supplies the output signal at 2 Mbit/sec.

6 CLAIMS 1. A transmission system for the transmission of information and/or commands from at least one rail vehicle to the next of the same train assembly, characterised in that it is designed such that the data items to be transmitted modulate, in coded form, a transmitter of electromagnetic waves of the first rail vehicle and the radiation from the said transmitter is transmitted by an antenna of the latter in the direction of the antenna of a receiver of electromagnetic waves of the second rail vehicle, and the information received in this way by the receiver of the second rail vehicle is forwarded and if necessary is demodulated or is demodulated and decoded.
2. A system as claimed in Claim 1, characterised in that in order to monitor the transmission path, the data items to be transmitted are fed back, unchanged in their contents, from the last rail vehicle of the train assembly to the first rail vehicle and are checked for accuracy.
3. A system as claimed in one of Claims 1 and 2, characterised in that a monitoring signal is fed into the internal data transmission system of the train assembly and it is established whether all the transmitterreceiver units coupled to each other are correctly connected to each other.
4. A system as claimed in one of Claims 1 to 3, characterised in that the data items to be transmitted are transmitted by means of two mutually independent data transmission systems from one rail vehicle to the next and in the event that the signals incoming therein are not identical an alarm signal is triggered.

1 7
5. A system as claimed in one of Claims 1 to 4, characterised in that at least two transmission paths extending in parallel with one another are provided in each of the rail vehicles in the longitudinal direction thereof, that the ends of said transmission paths each lead to a transmitting-receiving antenna and that transmission paths are preferably connected to one or more transmitting-receiving unit(s).
6. A system as claimed in one of Claims 1 to 5, characterised in that a plurality of transmission paths are provided, which operate at different frequencies to one another.
7. A system as claimed in Claim 6, characterised in that one and the same antenna is used for different transmission paths.
8. A system as claimed in one of Claims 1 to 7, characterised in that the antennae of the receiver and transmitter are arranged in the plane of symmetry of the rail vehicle at the front end thereof, preferably in the vicinity of the vehicle roof.
9. A system as claimed in one of Claims 1 to 8, characterised in that microwave radiation operating in the range from 1 to 20 GHz is used.
10. A system as claimed in Claim 9, characterised in that the antennae of the microwave transmitter and receiver are in the form of microstrip antennae and at least the near surrounding field of the antennae, preferably in the region surrounding these antennae whose breadth at least corresponds to the wave length being used, is designed to absorb the radiation which is used.

8
11. A system as claimed in Claim 9 or 10, characterised in that the radiation patterns of the antennae of the microwave transmitter and of the microwave receiver each possess a divergent characteristic and the antennae are in the form of microstrip antennae.
12. A system as claimed in one of Claims 1 to 8, characterised In that electromagnetic waves operating in the range from 1 to 50 MHz are used.
13. A system as claimed in Claim 12, characterised in that the antennae of the microwave transmitter and the microwave receiver are each in the form of a magnet coil.
14. A system as claimed in one of Claims 1 to 13, characterised in that additionally at least one stationary opposite station, comprising at least one microwave transmitter and/or microwave receiver, is provided.
15. A system as claimed in Claim 14, characterised in that the opposite station(s) is/are arranged in the region of the rails.

P193bobed 1991 atMw Patent Office. State House-66/71 High Holborn. LandonWIR47P. Further copies maybe obtained from Sales BMX436 Unit a N11ne We Point. CwmIchnfach. Cross Keys Newport. NPI = Printed by Multiplex techniques ltd. St Mary Cray. Kent.

1 i i 1 1