GB2355622A - Signalling through steel walls - Google Patents

Signalling through steel walls Download PDF

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Publication number
GB2355622A
GB2355622A GB9917095A GB9917095A GB2355622A GB 2355622 A GB2355622 A GB 2355622A GB 9917095 A GB9917095 A GB 9917095A GB 9917095 A GB9917095 A GB 9917095A GB 2355622 A GB2355622 A GB 2355622A
Authority
GB
United Kingdom
Prior art keywords
information
electromagnet
crawler
steel wall
transmitted
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.)
Withdrawn
Application number
GB9917095A
Other versions
GB9917095D0 (en
Inventor
Quinton Francis Lucy
John Macleod
Victor Kurosaev
Alexander Bakoonov
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.)
JME Ltd
Original Assignee
JME 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 JME Ltd filed Critical JME Ltd
Priority to GB9917095A priority Critical patent/GB2355622A/en
Publication of GB9917095D0 publication Critical patent/GB9917095D0/en
Publication of GB2355622A publication Critical patent/GB2355622A/en
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B5/00—Near-field transmission systems, e.g. inductive or capacitive transmission systems
    • H04B5/40—Near-field transmission systems, e.g. inductive or capacitive transmission systems characterised by components specially adapted for near-field transmission
    • H04B5/48—Transceivers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J27/00—Ion beam tubes
    • H01J27/02—Ion sources; Ion guns
    • H01J27/16—Ion sources; Ion guns using high-frequency excitation, e.g. microwave excitation
    • H01J27/18—Ion sources; Ion guns using high-frequency excitation, e.g. microwave excitation with an applied axial magnetic field

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
  • Near-Field Transmission Systems (AREA)

Abstract

A method of signalling information through a steel wall is described wherein an electromagnet 12 acting as a transmitter is located adjacent an inner (or outer) surface of a steel wall 10, a high sensitivity coil 18 acting as a receiver is employed to detect electromagnetic emissions from the outer (or inner) surface of the steel wall, and the electromagnet is energised by an a.c. signal 14 modulated 16 with the information to be transmitted through the steel wall to the receiver. The frequency of the a.c. signal used to energise the electromagnet, and act as a carrier for the information to be transmitted, lies in the range 50 to 600 Hz.

Description

2355622 Si2nallin,2 throu2h Steel Walls This invention relates generally
to signalling through steel walls and more specifically to a method of and apparatus for transmitting information through steel walls.
According to one aspect of the invention, there is provided a method of signalling information through steel walls wherein an electromagnet acting as a transmitter is located adjacent an inner (or outer) surface of a steel wall, a high sensitivity coil acting as a receiver is employed to detect electromagnetic emissions from the outer (or inner) surface of the steel wall, and the electromagnet is energised by an a.c. signal modulated with the information to be transmitted through the steel wall to the receiver.
Preferably, the a.c. signal used to energise the electromagnet, and act as a carrier for the information to be transmitted, operates in the range 50 to 600 Hz.
Within this range, the amplitude of the emissions to be detected by the high sensitivity receiver coil is maximised. Nevertheless, these emissions are of relatively low level, and desirably these signals are amplified in a high-gain receiver before being filtered and demodulated to recover the information being signalled.
The information to be signalled may be imposed on the transmitted signal by any convenient method of modulation, such as pulse position modulation (PPM), frequency shift keying (FSK) or frequency modulation (FM).
An example of use of the method is for signalling information to or from a crawler in a steel pipeline. The crawler may be controlled by the information carried by the transmitted signal, or information and/or data about the operations -2of the crawler in the pipeline may be signalled to the outside.
Prefer-red apparatus for use in carrying out the method according to the invention comprises an electromagnet, an a.c. source for energising the electromagnet, modulation means for modulating the a.c. signal from the source with the information or data to be transmitted, a high sensitivity receiver coil, means for amplifying the signal detected by the receiver coil, and means for demodulating the amplified signal to extract the information or data being signalled.
The precise nature of the mechanism by which the method according to the invention is made possible is not fully understood since, due to eddy currents and secondary flux generation in opposition to the primary flux, reliable detection of alternating magnetic flux transmission through steel has been considered impractical. Testing of the apparatus of the invention, however, in the context of a steel pipeline and crawler therein, has shown the method to be both efficient and reliable.
For completeness, a system in accordance with the invention is shown in the accompanying drawing, for transmission of signals from outside a steel pipe to the inside thereof.
The items outside the steel pipe 10 comprise a C-shaped or U-shaped electromagnet 12 having its polar axis (principal direction of magnetic flux) normal to the pipe axis, an a.c. source 14, and means 16 for modulating the a.c. signal with the information to be transmitted. The items inside the pipeline, for example on a pipeline crawler to be controlled, comprise a high sensitivity detector coil 18 having its axis normal to the pipe axis and parallel to the polar axis of the magnet, receiver 20, amplifier 22 and demodulator 24. Reference 26 indicates means responsive to the information extracted from the transmitted signal, e.g. a crawler control system.
a - I

Claims (11)

  1. I. A method of signalling information through a steel wall wherein an electromagnet acting as a transmitter is located adjacent an inner (or outer) surface of a steel wall, a high sensitivity coil acting as a receiver is employed to detect electromagnetic emissions from the outer (or inner) surface of the steel wall, and the electromagnet is energised by an ax signal modulated with the information to be transmitted through the steel wall to the receiver.
  2. 2. A method as claimed in claim 1, wherein the frequency of the a.c. signal used to energise the electromagnet, and act as a carrier for the information to be transmitted, lies in the range 50 to 600 Hz.
  3. 3. A method as claimed in claim I or 2, wherein the detected emissions are converted to a.c. currents in the coil and these currents are amplified, filtered, and demodulated, to recover the modulating information.
  4. 4. A method as claimed in claim 1, 2 or 3, wherein the information to be signalled is imposed on the transmitted signal by pulse position modulation (PPM), frequency shift keying (FSK) or frequency modulation (FM).
  5. 5. A method as claimed in any of claims I to 4, for signalling information to or from a crawler in a steel pipeline.
  6. 6. A method as claimed in claim 5, wherein the information is transmitted to the crawler and the latter is controlled by the information carried by the transmitted signal.
  7. 7. A method as claimed in claim 5 or 6, wherein a transmitter is located on the crawler and information and/or data about the operation of the crawler in the pipeline is signalled to a detector outside the pipeline.
    4
  8. 8. Apparatus for use in carrying out the method according to claim 1, comprising an electromagnet on one side of the steel wall, an a.c. source for energising the electromagnet, modulation means for modulating the a-c signal from the source with information or data to be transmitted, a high sensitivity receiver coil on the other side of the steel wall, means for amplifying electric signals induced in the receiver coil, and means for demodulating the amplified signal to extract the information or data being signalled.
  9. 9. Apparatus as claimed in claim 8, which further comprises filter circuit means for filtering the amplified signals prior to demodulation.
  10. 10. A method of controlling a crawler within a pipeline from outside the pipeline comprising the steps of locating an electromagnet transmitter outside the pipeline, locating a high sensitivity coil on the crawler, passing a modulated a.c current through the electromagnet having a carrier frequency in the range 50-60OHz, the modulation comprising, when demodulated, control signals for instructing the crawler, amplifying and demodulating signals received by a high sensitivity coil on the crawler and supplying the demodulated signals as control signals to the crawler.
  11. 11. Apparatus and methods of communicating through a steel wall using a modulated current flowing in an electromagnet substantially as herein described, with reference to as illustrated in the accompanying drawings.
GB9917095A 1999-07-22 1999-07-22 Signalling through steel walls Withdrawn GB2355622A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9917095A GB2355622A (en) 1999-07-22 1999-07-22 Signalling through steel walls

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9917095A GB2355622A (en) 1999-07-22 1999-07-22 Signalling through steel walls

Publications (2)

Publication Number Publication Date
GB9917095D0 GB9917095D0 (en) 1999-09-22
GB2355622A true GB2355622A (en) 2001-04-25

Family

ID=10857654

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9917095A Withdrawn GB2355622A (en) 1999-07-22 1999-07-22 Signalling through steel walls

Country Status (1)

Country Link
GB (1) GB2355622A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105172929A (en) * 2015-09-30 2015-12-23 昆明鑫辉检测有限公司 Steel wall crawl device with left tray and right tray capable of floating in multiple directions

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3691385A (en) * 1968-06-06 1972-09-12 Houston Gamma Ray Co Control system for welding inspection machine
GB1296257A (en) * 1969-10-01 1972-11-15
GB1538132A (en) * 1975-07-09 1979-01-10 Mefina Sa Information transmitting system
GB2105041A (en) * 1981-07-25 1983-03-16 Ferranti Ltd Pipeline traveller detection system
GB2107063A (en) * 1981-09-23 1983-04-20 British Gas Corp Fixing geographical reference of pipeline pigs in pipelines
GB2138248A (en) * 1983-03-28 1984-10-17 Inst Francais Du Petrole Near field signal transmission system
GB2202414A (en) * 1987-03-10 1988-09-21 Oxley Dev Co Ltd Transmission of power and/or data
EP0302841A2 (en) * 1987-08-04 1989-02-08 Franco Fratta A device for the control and automatic positioning of equipment trolleys used in verifying pipeline weldments by radiography
EP0356741A1 (en) * 1988-08-08 1990-03-07 FABBRICHE RIUNITE MISURATORI SACOFGAS S.p.A Process and apparatus for transmitting measurements through a metal pipe
GB2297666A (en) * 1995-01-31 1996-08-07 British Gas Plc Signalling to a vehicle inside a pipeline

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3691385A (en) * 1968-06-06 1972-09-12 Houston Gamma Ray Co Control system for welding inspection machine
GB1296257A (en) * 1969-10-01 1972-11-15
GB1538132A (en) * 1975-07-09 1979-01-10 Mefina Sa Information transmitting system
GB2105041A (en) * 1981-07-25 1983-03-16 Ferranti Ltd Pipeline traveller detection system
GB2107063A (en) * 1981-09-23 1983-04-20 British Gas Corp Fixing geographical reference of pipeline pigs in pipelines
GB2138248A (en) * 1983-03-28 1984-10-17 Inst Francais Du Petrole Near field signal transmission system
GB2202414A (en) * 1987-03-10 1988-09-21 Oxley Dev Co Ltd Transmission of power and/or data
EP0302841A2 (en) * 1987-08-04 1989-02-08 Franco Fratta A device for the control and automatic positioning of equipment trolleys used in verifying pipeline weldments by radiography
EP0356741A1 (en) * 1988-08-08 1990-03-07 FABBRICHE RIUNITE MISURATORI SACOFGAS S.p.A Process and apparatus for transmitting measurements through a metal pipe
GB2297666A (en) * 1995-01-31 1996-08-07 British Gas Plc Signalling to a vehicle inside a pipeline

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105172929A (en) * 2015-09-30 2015-12-23 昆明鑫辉检测有限公司 Steel wall crawl device with left tray and right tray capable of floating in multiple directions
CN105172929B (en) * 2015-09-30 2017-05-31 昆明鑫辉检测有限公司 Steel wall crawl device with the multi-direction left and right disk that floats

Also Published As

Publication number Publication date
GB9917095D0 (en) 1999-09-22

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)