GB2222902A - Railway vehicle location system - Google Patents

Railway vehicle location system Download PDF

Info

Publication number
GB2222902A
GB2222902A GB8821799A GB8821799A GB2222902A GB 2222902 A GB2222902 A GB 2222902A GB 8821799 A GB8821799 A GB 8821799A GB 8821799 A GB8821799 A GB 8821799A GB 2222902 A GB2222902 A GB 2222902A
Authority
GB
United Kingdom
Prior art keywords
metal plates
plates
code
series
transponder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB8821799A
Other versions
GB2222902B (en
GB8821799D0 (en
Inventor
Robert Edward Blake Barnard
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
GEC General Signal Ltd
Original Assignee
GEC General Signal Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by GEC General Signal Ltd filed Critical GEC General Signal Ltd
Priority to GB8821799A priority Critical patent/GB2222902B/en
Publication of GB8821799D0 publication Critical patent/GB8821799D0/en
Publication of GB2222902A publication Critical patent/GB2222902A/en
Application granted granted Critical
Publication of GB2222902B publication Critical patent/GB2222902B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B61RAILWAYS
    • B61LGUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC
    • B61L25/00Recording or indicating positions or identities of vehicles or vehicle trains or setting of track apparatus
    • B61L25/02Indicating or recording positions or identities of vehicles or vehicle trains
    • B61L25/021Measuring and recording of train speed
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B61RAILWAYS
    • B61LGUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC
    • B61L25/00Recording or indicating positions or identities of vehicles or vehicle trains or setting of track apparatus
    • B61L25/02Indicating or recording positions or identities of vehicles or vehicle trains
    • B61L25/023Determination of driving direction of vehicle or vehicle train
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B61RAILWAYS
    • B61LGUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC
    • B61L25/00Recording or indicating positions or identities of vehicles or vehicle trains or setting of track apparatus
    • B61L25/02Indicating or recording positions or identities of vehicles or vehicle trains
    • B61L25/025Absolute localisation, e.g. providing geodetic coordinates

Abstract

The system comprises a passive coded device mounted beside the track at stations, junctions, etc. A reader on the train 11 scans the device and decodes a digital message giving the location. The device consists of a number of metal plates 19 fixed on a non-conductive base 21 extending along the track. An inductive proximity detector 15 carried by the train passes closely over the plates and produces a pulse for the duration of the proximity. The plates may be arranged in a Manchester 2 code and may alternatively be arranged across the track, with corresponding increase in the required number of detectors. <IMAGE>

Description

Railway Vehicle Location System This invention relates to a railway vehicle location system for use by a railway vehicle in determining its position along a track.
Transponders, and in particular passive transponders, have been used to identify objects, vehicles and locations in railway systems. In particular, on guided transport systems, transponders on vehicles may be used to identify the vehicles passing a reader on the track. Alternatively, transponders on the track may be used to identify particular locations to passing vehicles, by means of readers on-board the vehicles.
A typical passive transponder (which is usually intended to be as cheap as possible) is a sealed unit 1, as shown in Figure 1, containing electronic circuits, together with receiver and transmitter aerials 3 and 5. Power at a high frequency, from the reader 7, is used to energise the transponder circuits inductively via its receiver aerial 3, and this causes the transponder to transmit a stored message, operated by a message generator 9, to the reader, via the transmitter aerial 5. Some transponders may also be capable of transmitting different data messages, according to the state of controlling inputs (e.g. relay contacts).
Because of the poor efficiency of energy transfer between the reader and the transponder, the transponder message received by the reader often has a very low signal-to-noise ratio, making the reading circuits prone to interference (e.g. from electric traction systems), and also costly and complex. Moreover, since the transponder contains electronic circuits, which must be designed and packaged to be capable of surviving in harsh environments, it is often relatively costly in practice.
It is an object of the present invention to overcome at least some of these disadvantages of known transponder systems.
According to the present invention, a railway vehicle location system comprises a trackside transponder and a reader mounted on a railway vehicle, the transponder comprising a plurality of passive metal plates disposed adjacent the track in such relation to proximity detector means mounted on the vehicle that a signal pulse arises in the proximity detector means for the duration of proximity between the detector means and each metal plate as the vehicle passes the transponder, the plurality of plates thereby producing a signal code identifying to the vehicle the location of the transponder. The proximity detector means may operate by magnetic induction.
The signal code may be constituted by the length and relative position of the metal plates in a series, and may comprise a series of code units, each code unit comprising a pair of opposite binary elements in an order determining the value of the code unit, one binary element being represented by a metal plate and the other binary element being represented by the absence of metal plate in a predetermined position.
The metal plates may be disposed in the direction of travel and be of one or two units length interspersed with spaces of one or two units length, according to the value of successive code units, equal or different.
Alternatively, the signal code may be constituted by the presence and absence of metal plates in a parallel array of similar metal plates relative to the direction of vehicle travel, there being a respective proximity detector for each potential metal plate position.
Moreover, the signal code may be constituted by the presence and absence of metal plates in a series/parallel array of similar metal plates, there being a respective proximity detector for each row of the array, the rows lying in the direction of vehicle travel.
In the serial arrangement, transitions between the presence and absence of plates may be detected and the signal code determined from the time between successive transitions.
The series of metal plates may be preceded by a synchronisation pattern of metal plates indicating to the reader the timing of code units in the following series of metal plates. There may be such a synchronisation pattern at both ends to accommodate vehicle travel in both directions.
The series of metal plates may further include a signal code indicative of the direction of travel.
A railway vehicle location system will now be described, by way of example, with reference to the accompanying drawings, of which: Figure 1 is a block diagram of a known radio transponder identification/location system; Figure 2 is a diagram of a locomotive on a track carrying a serial pattern of transponder plates; Figure 3 is a diagram of a serial pattern of transponder plates illustrating the derived transitions; and Figure 4 is a diagram of a locomotive on a track carrying a parallel pattern of transponder plates.
Referring to the drawings, a known radio transponder system has already been described as illustrated in Figure 1.
Figure 2 shows a locomotive 11 with driver 13, the locomotive carrying an inductive proximity detector 15 of known form, which is mounted to run alongside the track, whether between or outside the rails 17. A pattern of conductive metal plates 19, made for example, of aluminium, is mounted on a non-conductive base 21, which is fixed to the sleepers (not shown). Depending upon the length of the pattern, the base 21 may be in sections although the spacing of the sections must be controlled to conform to the basic pattern requirements, as will be explained with reference to Figure 3.
The proximity detector 15 produces a two level signal according to its position in proximity to a metal plate, i.e. over one, or not over one. The position of the plate pattern is such that the detector runs within about 100 millimetres of the surface. The pattern may of course be mounted on a vertical 'base' the detector then running alongside it.
Figure 2 shows a typical serial data pattern 23 as produced by the proximity detector, the detector providing this signal to a data processor 25 which incorporates a clock pulse generator and a program for the analysis of the signal. The output of the processor is the identity of the particular location, a station or intersection for example, which is displayed to the driver and perhaps also transmitted by radio to a control centre.
Referring now to Figure 3, this shows a series of plates 19 some (19') of one 'unit' length and some (19") of two units length.
The spacings 23 between plates are similarly of one unit (23') or two units (23") length, in the direction of travel.
The particular signal code employed in this example is that known as the Manchester 2 code, according to which an individual code unit, logical '0' or logical '1' is represented by two binary elements in a particular order. Thus, logical '0' is represented by 01 and logical '1' by 10. In a series of code units therefore, e.g. logical '0', logical '1', logical 1, logical 0, there will be single O's and l's and pairs of O's and 1's in sequence according to the value of successive code units. If a binary element of value '1' is represented by a unit length of metal plate and a binary element of value '0' by a unit length of space then a signal code in metal plates will be represented by plates of one and two units length interspersed by spaces of one and two units length as shown in Figures 2 and 3.
Decoding of such a pattern relies upon first detecting the transitions between spaces and plates and then determining the time between transitions. Since the time between transitions clearly cepends upon the speed of the train, a reference time is provided by a sync pattern preceding the coded signal message as shown in Figure 3.
In this case the sync pattern comprises a two-unit metal plate 19" followed by a two-unit space 23" and this cycle repeated once.
At each transition from a 'O' to a '1', i.e. from space to plate, the processor sets a clock to time the duration of the '1'.
Following the next 1/0 transition the processor times the duration of the '0' before the new 0/1 transition and if comparable (i.e. within a tolerance margin) averages the two periods and times the next '1'. If not comparable the check is rejected. This process is repeated up to the fifth transition as shown in Figure 3, each successive transition giving an improvement in the estimated value of a two-unit period. A single unit period is then derived and the two reference periods so produced used for assessing the durations of the plates and spaces of the subsequent data message. After each transition a comparison is made to determine the duration of the previous state as one unit or two and a further improvement in the estimated value of a single unit period is made, e.g. to cater for acceleration or braking of the train.The pattern is then apparent and the two-unit states can be split to give a series of single unit states exclusively. In Figure 3 the durations in units are: 1(1) 1(l) 1(1) 2(0) 2(1) 2(0) 1(l) I(o > 1(0) On splitting, this becomes: 1 0 1 0 0 1 1 0 0 1 0 .....
On pairing according to the Manchester 2 code: 10 10 01 10 01 01 and hence a data message reading: 110100 which is the digital address of a station or other location.
In order to make the transponder available for use by trains in both directions, on a single-line track for example, a sync pattern is provided at both ends of the message portion and a coded message portion incorporated which indicates to the driver (and to the central control) which way the train is going. The data message will of course be read in the wrong direction but this can be stored and read forward or backward according to the direction code.
The plates have been described as conductive plates which are suitable for detection by an inductive sensor, the plate providing in effect a short circuited secondary winding of a transformer the primary of which is energised in the proximity detector. The current drawn by the primary will increase in the presence of the plate and the current magnitude can be measured.
Alternatively, the plates may be essentially magnetic, thus increasing the inductance of a coil in the proximity detector and altering an oscillator frequency. The plates must of course be sufficiently remote from the magnetic/conductive rails. A central position between the rails is suitable both for this non-interference requirement and for single-line two-way running.
Again, the plates may form a common capacitor plate between two co-planar capacitor plates on the proximity detector thus again modulating the frequency of an oscillator.
In an alternative to the above serial arrangement of the signal code pattern, plates 29 may be arranged in parallel, i.e.
across the track, as shown in Figure 4. In this case there is a respective proximity detector 25 for each plate position 27 and the bank of detectors reads the data message directly, without any 2-bit coding. Precautions have to be taken to ensure that for example, a single detector triggered does not imply a data message. A parity or near parity code overcomes this difficulty. Alternatively, a combination serial/parallel arrangement may be employed in which the plates 29 are uniformly staggered along the travel direction to impose a time constraint on acceptable pulses.
In a further variation two serial rows of plates may be used, one providing a synchronisation pattern, say a regular series of plates equally spaced, while the other comprises the data message pattern of equal plates equally spaced but with certain ones (representing logical O's) omitted.
Several advantages arise from the above described transponders: (a) The transponder (which may be required in large quantities ) consists only of common engineering materials, and it could therefore be made by relatively unskilled staff e.g. in a developing country.
(b) The transponder is capable (at zero or minimal additional cost) of conveying not only location information, but also direction of travel information to each passing train.
(c) The train may be economically fitted with more than one reader head (proximity detector) since they are simple and potentially inexpensive. The use of more than one head can help prevent loss of data in the event of the locomotive stopping with its reader head over the pattern.
(d) There is potential for measuring the speed of the train, by one of the following methods: - From the bit rate calculated by the reader processor.
- By timing the train between two successive transponders.
- By timing between 2 heads on a locomotive passing over the same transponder.
Such methods of speed measurement operate independently of wheel slip/slide.

Claims (12)

1. A railway vehicle location system comprising a trackside transponder and a reader mounted on a railway vehicle, the transponder comprising a plurality of passive metal plates disposed adjacent the track in such relation to proximity detector means mounted on the vehicle that a signal pulse arises in the proximity detector means for the duration of proximity between the detector means and each metal plate as the vehicle passes the transponder, the plurality of plates thereby producing a signal code identifying to the vehicle the location of the transponder.
2. A system according to Claim 1, wherein said proximity detector means operates by magnetic induction.
3. A system according to Claim 1 or Claim 2, wherein said signal code is constituted by the length and relative position of said metal plates in a series.
4. A system according to Claim 1 or Claim 2, wherein said signal code comprises a series of code units, each code unit comprising a pair of opposite binary elements in an order determining the value of the code unit, one binary element being represented by a said metal plate and the other binary element being represented by the absence of metal plate in a predetermined position.
5. A system according to Claim 4, wherein said metal plates are disposed in the direction of travel and are of one or two units length interspersed with spaces of one or two units length, according to the value of successive code units, equal or different.
6. A system according to Claim 1 or Claim 2, wherein a signal code is constituted by the presence and absence of metal plates in a parallel array of similar metal plates relative to the direction of vehicle travel, there being a respective proximity detector for each potential metal plate position.
7. A system according to Claim 6, wherein a signal code is constituted by the presence and absence of metal plates in a series/parallel array of similar metal plates, there being a respective proximity detector for each row of the array, the rows lying in the direction of vehicle travel.
8. A system according to Claim 5, wherein transitions between the presence and absence of said plates are detected and the signal code determined from the time between successive transitions.
9. A system according to Claim 5 or Claim 8, wherein the series of metal plates is preceded by a synchronisation pattern of metal plates indicating to the reader the timing of code units in the following series of metal plates.
10. A system according to Claim 9, wherein the series of metal plates is terminated by a said synchronisation pattern at both ends to accommodate vehicle travel in both directions.
11. A system according to Claim 10, wherein said series of metal plates includes a signal code indicative of the direction of travel.
12. A railway vehicle location system substantially as hereinbefore described with reference to the accompanying drawings.
GB8821799A 1988-09-16 1988-09-16 Railway vehicle location system Expired - Fee Related GB2222902B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8821799A GB2222902B (en) 1988-09-16 1988-09-16 Railway vehicle location system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB8821799A GB2222902B (en) 1988-09-16 1988-09-16 Railway vehicle location system

Publications (3)

Publication Number Publication Date
GB8821799D0 GB8821799D0 (en) 1988-10-19
GB2222902A true GB2222902A (en) 1990-03-21
GB2222902B GB2222902B (en) 1992-07-22

Family

ID=10643731

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8821799A Expired - Fee Related GB2222902B (en) 1988-09-16 1988-09-16 Railway vehicle location system

Country Status (1)

Country Link
GB (1) GB2222902B (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0949495A1 (en) * 1998-04-02 1999-10-13 Volkswagen Aktiengesellschaft Device and method for simulating a motor vehicle accident
EP1396412A1 (en) * 2002-08-13 2004-03-10 Kunihiro Kishida Vehicle detection system, in particular for trains
FR2963683A1 (en) * 2010-08-05 2012-02-10 Senstronic Sensor for detecting e.g. hook, fixed on surface-mount component strip, has tab with free end provided opposite to detection surface, so that strip is provided between free end and surface and metal element passes close to detection element
DE102010047580A1 (en) * 2010-10-07 2012-04-12 Deutsches Zentrum für Luft- und Raumfahrt e.V. Method for determining information
CN103192853A (en) * 2013-03-21 2013-07-10 中国铁道科学研究院 Train speed measurement and location method and system based on network distributed redundancy framework
EP2724180A1 (en) * 2011-06-24 2014-04-30 Thales Canada Inc. Vehicle localization system
FR3055876A1 (en) * 2016-09-12 2018-03-16 Alstom Transport Technologies METHOD FOR DETERMINING THE POSITION OF A RAILWAY VEHICLE AND ASSOCIATED RAILWAY INSTALLATION
CN108891448A (en) * 2018-07-12 2018-11-27 中铁磁浮科技(成都)有限公司 A kind of magnetic-levitation train speed-position detection system and method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1167302A (en) * 1966-01-07 1969-10-15 Ass Elect Ind Improvements relating to Sorting Apparatus
GB1374100A (en) * 1970-11-26 1974-11-13 Sumitomo Electric Industries Device for detecting location of moving body
GB1376667A (en) * 1973-04-27 1974-12-11 British Railways Board Vehicle communication system
GB2112982A (en) * 1981-11-02 1983-07-27 Mitsui Shipbuilding Eng Position detecting arrangements for mobile cranes

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1167302A (en) * 1966-01-07 1969-10-15 Ass Elect Ind Improvements relating to Sorting Apparatus
GB1374100A (en) * 1970-11-26 1974-11-13 Sumitomo Electric Industries Device for detecting location of moving body
GB1376667A (en) * 1973-04-27 1974-12-11 British Railways Board Vehicle communication system
GB2112982A (en) * 1981-11-02 1983-07-27 Mitsui Shipbuilding Eng Position detecting arrangements for mobile cranes

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0949495A1 (en) * 1998-04-02 1999-10-13 Volkswagen Aktiengesellschaft Device and method for simulating a motor vehicle accident
EP1396412A1 (en) * 2002-08-13 2004-03-10 Kunihiro Kishida Vehicle detection system, in particular for trains
FR2963683A1 (en) * 2010-08-05 2012-02-10 Senstronic Sensor for detecting e.g. hook, fixed on surface-mount component strip, has tab with free end provided opposite to detection surface, so that strip is provided between free end and surface and metal element passes close to detection element
DE102010047580A1 (en) * 2010-10-07 2012-04-12 Deutsches Zentrum für Luft- und Raumfahrt e.V. Method for determining information
DE102010047580B4 (en) * 2010-10-07 2012-07-12 Deutsches Zentrum für Luft- und Raumfahrt e.V. Method for determining information
EP2724180A1 (en) * 2011-06-24 2014-04-30 Thales Canada Inc. Vehicle localization system
EP2724180A4 (en) * 2011-06-24 2015-01-21 Thales Canada Inc Vehicle localization system
CN103765242A (en) * 2011-06-24 2014-04-30 泰雷兹加拿大公司 Vehicle localization system
JP2014527157A (en) * 2011-06-24 2014-10-09 タレス・カナダ・インコーポレイテッド Vehicle localization system
CN103192853A (en) * 2013-03-21 2013-07-10 中国铁道科学研究院 Train speed measurement and location method and system based on network distributed redundancy framework
CN103192853B (en) * 2013-03-21 2015-08-05 中国铁道科学研究院 The method and system of the train speed and position measurement of distributed redundancy structure Network Based
FR3055876A1 (en) * 2016-09-12 2018-03-16 Alstom Transport Technologies METHOD FOR DETERMINING THE POSITION OF A RAILWAY VEHICLE AND ASSOCIATED RAILWAY INSTALLATION
CN108891448A (en) * 2018-07-12 2018-11-27 中铁磁浮科技(成都)有限公司 A kind of magnetic-levitation train speed-position detection system and method

Also Published As

Publication number Publication date
GB2222902B (en) 1992-07-22
GB8821799D0 (en) 1988-10-19

Similar Documents

Publication Publication Date Title
US10000222B2 (en) Methods and systems of determining end of train location and clearance of trackside points of interest
US5019815A (en) Radio frequency controlled interrogator-responder system with passive code generator
EP0685825B1 (en) Electronic identification system
US4459474A (en) Identification system with separation and direction capability and improved noise rejection
US3377616A (en) Vehicle identification system
CN102616249B (en) System and method for broken rail and train detection
AU611768B2 (en) A payment system for users of transport means
US4185265A (en) Vehicular magnetic coded signalling apparatus
CN100532175C (en) Automatic train protection stop apparatus for controlling train using data communication
US6511023B2 (en) Automated railway monitoring system
CA1060954A (en) Transponder system for the transfer of signalling information for rail-bounded vehicles
EP0417267B1 (en) Vehicle tire identification system
CA2106635C (en) Railway coded track circuit apparatus and method utilizing fiber optic sensing
US5055659A (en) High speed system for reading and writing data from and into remote tags
EP0245606B1 (en) Automatic/remote rf instrument reading system
US6416020B1 (en) Method and apparatus for detecting defective track wheels
US5602538A (en) Apparatus and method for identifying multiple transponders
EP1701287B1 (en) Identification system and method for determining movement informations
SU1068051A3 (en) Device for transmitting and receiving signals
ES2209141T3 (en) READER FOR RADIO-FREQUENCY IDENTIFICATION SYSTEM.
US4728063A (en) Railway signalling system especially for broken rail detection
US4931793A (en) System for providing a warning when vehicles approach a common collision point
US3696758A (en) Locomotive signaling and control system
US4130874A (en) Load management terminal having plural selectable address formats for a power line communication system
US3419865A (en) Mobile emergency unit locating system

Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 20040916