WO2000057148A1 - Strain sensing - Google Patents
Strain sensing Download PDFInfo
- Publication number
- WO2000057148A1 WO2000057148A1 PCT/GB2000/000994 GB0000994W WO0057148A1 WO 2000057148 A1 WO2000057148 A1 WO 2000057148A1 GB 0000994 W GB0000994 W GB 0000994W WO 0057148 A1 WO0057148 A1 WO 0057148A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- light
- wavelength
- change
- strain
- reflecting
- Prior art date
Links
- 238000002310 reflectometry Methods 0.000 claims abstract description 36
- 230000003287 optical effect Effects 0.000 claims abstract description 18
- 239000013307 optical fiber Substances 0.000 claims description 30
- 239000000835 fiber Substances 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 16
- 230000002238 attenuated effect Effects 0.000 claims description 8
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 6
- 230000005540 biological transmission Effects 0.000 claims description 6
- YBMRDBCBODYGJE-UHFFFAOYSA-N germanium oxide Inorganic materials O=[Ge]=O YBMRDBCBODYGJE-UHFFFAOYSA-N 0.000 claims description 4
- PVADDRMAFCOOPC-UHFFFAOYSA-N oxogermanium Chemical compound [Ge]=O PVADDRMAFCOOPC-UHFFFAOYSA-N 0.000 claims description 4
- 239000002019 doping agent Substances 0.000 claims description 3
- 239000000377 silicon dioxide Substances 0.000 claims description 3
- 230000001419 dependent effect Effects 0.000 claims 1
- 238000010408 sweeping Methods 0.000 claims 1
- 230000003595 spectral effect Effects 0.000 description 16
- 238000012544 monitoring process Methods 0.000 description 5
- 238000001228 spectrum Methods 0.000 description 4
- 230000008602 contraction Effects 0.000 description 3
- 230000009977 dual effect Effects 0.000 description 3
- 208000032365 Electromagnetic interference Diseases 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052691 Erbium Inorganic materials 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- UYAHIZSMUZPPFV-UHFFFAOYSA-N erbium Chemical compound [Er] UYAHIZSMUZPPFV-UHFFFAOYSA-N 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000012886 linear function Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/24—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet
- G01L1/242—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
- G01B11/18—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge using photoelastic elements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35383—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using multiple sensor devices using multiplexing techniques
Definitions
- This invention relates to strain sensing and more especially to a strain sensor, apparatus
- sensors relied on a change in electrical resistance with strain and typically comprised four
- Optical fibre strain sensors comprise an
- optical fibre containing a number of components which are responsive to applied strain.
- Such components can comprise birefringent elements, micro-bends, Fabry-Perot
- each Bragg grating which itself constitutes a respective strain
- This characteristic wavelength will change if the optical fibre is subjected
- the Bragg grating characteristic wavelength is a linear function of change
- fibre Bragg gratings are inherently wavelength encoded and consequently
- the optical fibre eliminates any point of mechanical weakness, they are immune to
- EMI electro-magnetic interference
- Fibre Bragg gratings can be addressed in the
- optical sources is 30 to 40 nm and it is usually required to be able to measure strains in
- the present invention has arisen in an endeavour to overcome at least in part the
- a strain sensor comprises an optical waveguide having a plurality of reflecting structures along its length, wherein each structure reflects light
- wavelength is based on the relative magnitude of their reflectivities, this allows reflecting
- any change in length of the object will cause a change in the length of the object
- any change in temperature will cause a change in the physical length of the
- the strain sensor of the present invention thus acts as an effective temperature sensor. It
- strain sensor is intended to be construed broadly as a sensor which relies on a change in
- the reflecting structure which reflects light at two characteristic
- wavelengths is configured such that the two wavelengths are separated by at least the
- optical waveguide comprises an optical fibre and preferably the
- each reflecting structure comprises a grating structure, most preferably a Bragg grating,
- the optical fibre includes a photo
- refractive dopant such as for example a silica optical fibre doped with germanium oxide
- each grating structure is optically written into the fibre core by, for example,
- an apparatus for measuring strain comprises a strain sensor described above; a light source operable to apply light to the
- said light having a wavelength range which covers at least the
- the detector means measures light
- the detector means further comprises means
- a method of measuring strain comprises
- said light having a wavelength range which covers at least the range of wavelengths over which the reflecting structure reflects light, and detecting any change in the characteristic
- the method further comprises detecting the relative magnitude of the intensity
- the method further comprises
- the method further comprises placing a part of
- the waveguide having at least a part of one of the reflecting structures in thermal contact
- Figure 1 is a schematic of a strain and/or temperature sensing apparatus in accordance
- Figure 2(a) is a series of plots of measured reflectivity I versus wavelength for different
- Figure 2(b) is a plot of the measured wavelength shift ⁇ of the peak (x) of Figure 2(a)
- Figure 3(a) is a series of plots of measured reflectivity I versus wavelength for a further
- Figure 3(b) is a plot of the measured wavelength shift ⁇ for the two peaks (x,y) of
- a strain sensing apparatus comprises a broad band light source 2,
- optical fibre strain 10 and 12 respectively, a mixer circuit 14 and a processor 16.
- silica optical fibre which is doped germanium oxide.
- Each grating is produced within the core of the optical fibre by exposing the core of the fibre to ultra-violet (UN) light using holographic
- Germanium oxide is a photo refractive dopant which when exposed to UV light
- Each grating structure within the fibre is selected to have a characteristic wavelength
- the gratings which reflect at adjacent wavelengths, for example ⁇ ⁇ and ⁇ j or ⁇ n and ⁇ n+1
- the optical fibre sensor 6 further comprises
- each grating region mechanical securing means to enable the fibre to be
- Such mechanical securing means can comprise an encapsulating tube, flanges or mounting brackets made
- the broad band light source 2 which conveniently comprises a light emitting diode or
- Erbium doped fibre amplifier is operable to produce a continuous broad band light
- wavelength selective filter 4 which can comprise for example an acousto-
- optical output which is swept over the range of wavelengths of the broad band source 2.
- the light source 2 and tuneable filter 4 can be replaced with
- a suitable optical source which is tuneable in the wavelength domain such as for example
- the swept light output is applied to the first input of the
- directional coupler 8 which splits the light such that half passes into and along the optical
- reflected by the optical fibre sensor 6 passes along the length of the optical fibre and is
- the output from the mixer 14 represents the reflection spectrum of the sensor 6 which has been normalised relative to the light applied to it and this spectrum is detected by the processor 16 which preferably comprises a spectrum analyser. It is preferable, though not essential, to normalise the reflection spectrum as described since the source 2 is unlikely to produce a uniform light intensity output over its full spectral range.
- FIG. 2(a) there are shown the reflection intensity I profiles for a pair of "low” and “high” reflectivity gratings which are adjacent in wavelength versus wavelength for increasing amounts of applied tensile strain to the "low” reflectivity grating.
- These test data are for a sensor having an array of Bragg gratings having a 2nm spectral spacing and a typical grating bandwidth of ⁇ 0.4nm.
- the "high” (95%) reflectivity grating was kept strain free whilst the "low” (50%) reflectivity grating was strained in steps of 80 ⁇ up to 4000 ⁇ , which corresponds to a 4nm change in wavelength.
- Figure 2(b) is a plot of the wavelength shift ⁇ of the reflectivity peak x versus applied
- n ⁇ SR / ⁇ BG where ⁇ ⁇ SR is the spectral range of the light source
- ⁇ BG is the spectral bandwidth of each fibre Bragg grating.
- ⁇ BG is necessary to ensure that reflection peaks for adjacent gratings do not cross each
- the sensor of the present invention additionally
- narrow spectral response gratings will reflect less light, which will degrade the signal to noise
- the sensor is
- strain sensor has been described by way of example to strain sensing
- strain sensor and apparatus can also be used to measure temperature, since a change in temperature of the grating will cause
- optical fibre is placed in thermal contact, with the object rather than being secured to it.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Optical Transform (AREA)
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA002366557A CA2366557A1 (en) | 1999-03-19 | 2000-03-17 | Strain sensing |
US09/936,551 US6816638B1 (en) | 1999-03-19 | 2000-03-17 | Strain sensing |
AU33058/00A AU3305800A (en) | 1999-03-19 | 2000-03-17 | Strain sensing |
DE60014631T DE60014631T2 (en) | 1999-03-19 | 2000-03-17 | STRAIN MEASUREMENT |
EP00911061A EP1183510B1 (en) | 1999-03-19 | 2000-03-17 | Strain sensing |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9906361.2 | 1999-03-19 | ||
GB9906361A GB2348000B (en) | 1999-03-19 | 1999-03-19 | Strain sensing |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2000057148A1 true WO2000057148A1 (en) | 2000-09-28 |
Family
ID=10849964
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/GB2000/000994 WO2000057148A1 (en) | 1999-03-19 | 2000-03-17 | Strain sensing |
Country Status (7)
Country | Link |
---|---|
US (1) | US6816638B1 (en) |
EP (1) | EP1183510B1 (en) |
AU (1) | AU3305800A (en) |
CA (1) | CA2366557A1 (en) |
DE (1) | DE60014631T2 (en) |
GB (1) | GB2348000B (en) |
WO (1) | WO2000057148A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2372322B2 (en) † | 2010-04-01 | 2023-08-09 | Koninklijke BAM Groep N.V. | System and method for determining the axle load of a vehicle and a sensor device |
Families Citing this family (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2372100B (en) * | 2001-02-13 | 2003-04-16 | Marconi Caswell Ltd | Optical Waveguide Bragg Grating System |
DE10145350B4 (en) * | 2001-09-14 | 2006-03-30 | Airbus Deutschland Gmbh | Increasing the resolution of Bragg sensor measurement systems |
US6876786B2 (en) * | 2002-10-02 | 2005-04-05 | Cicese-Centro De Investigation | Fiber-optic sensing system for distributed detection and localization of alarm conditions |
US7129470B2 (en) | 2003-06-04 | 2006-10-31 | Weatherford/Lamb, Inc. | Optical sensor using a long period grating suitable for dynamic interrogation |
US7488929B2 (en) * | 2003-08-13 | 2009-02-10 | Zygo Corporation | Perimeter detection using fiber optic sensors |
BRPI0403268B1 (en) * | 2004-08-10 | 2017-07-18 | Petroleo Brasileiro S.A. - Petrobras | SYSTEM FOR READING AND DATA ACQUISITION FOR FIBER OPTICAL SENSORS |
EP1800087A2 (en) * | 2004-10-15 | 2007-06-27 | Morgan Research Corporation | Embeddable polarimetric fiber optic sensor and method for monitoring of structures |
WO2006075972A1 (en) * | 2005-01-14 | 2006-07-20 | Sif Universal Pte Ltd | Bending sensor arrangement |
DE102005020125B3 (en) * | 2005-04-29 | 2006-10-12 | Siemens Ag | Device to measure contact force on a current pick up on the drive wire of an overhead wire for a rail driven vehicle has extension sensor with force measuring cells and an evaluation system |
DE102006027414A1 (en) * | 2006-06-13 | 2007-12-27 | Siemens Ag | Fiber optic measuring device for determining restraint forces of e.g. pelvic belt, in motor vehicle, has strap at which measuring point is fitted by textile, where change of characteristics of fiber at point causes change of fiber behavior |
US8525979B2 (en) * | 2008-06-16 | 2013-09-03 | Duhane Lam | Monitoring device for detecting stress strain and method for using same |
CN101701450B (en) * | 2009-09-30 | 2011-12-21 | 法尔胜集团公司 | Bridge intelligent cable system with built-in fiber grating sensor |
DE102010035958B8 (en) * | 2010-08-31 | 2012-07-05 | Airbus Operations Gmbh | Device and method for producing a component and aircraft structural component |
IN2014DN03226A (en) * | 2011-09-30 | 2015-05-22 | Vestas Wind Sys As | |
WO2013117954A1 (en) * | 2012-02-09 | 2013-08-15 | Osmos Sa | A monitoring device, system and method for the monitoring of an area of building or land, using at least one light waveguide |
GB201503861D0 (en) * | 2015-03-06 | 2015-04-22 | Silixa Ltd | Method and apparatus for optical sensing |
US9983121B2 (en) * | 2015-04-23 | 2018-05-29 | Faz Technology Limited | Photonic sensor tracking |
FR3049342B1 (en) * | 2016-03-23 | 2018-04-13 | Universite De Nantes | FIBER OPTIC CURVE SENSOR AND MEASURING DEVICE COMPRISING SAID SENSOR |
NL2016744B1 (en) * | 2016-05-09 | 2017-11-16 | Fugro Tech Bv | Fiber-optic based traffic and infrastructure monitoring system |
CN117270098A (en) * | 2017-10-02 | 2023-12-22 | 直观外科手术操作公司 | Optical fiber with micro-gratings and methods and apparatus for making and using the same |
CN112798262B (en) * | 2021-02-05 | 2022-09-27 | 天津求实飞博科技有限公司 | Shield constructs quick-witted tool bit wearing and tearing monitoring devices based on fiber grating |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0216565A2 (en) * | 1985-09-10 | 1987-04-01 | Gec-Marconi Limited | Improvements relating to optical devices |
US5680489A (en) * | 1996-06-28 | 1997-10-21 | The United States Of America As Represented By The Secretary Of The Navy | Optical sensor system utilizing bragg grating sensors |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2268581A (en) * | 1992-07-03 | 1994-01-12 | Marconi Gec Ltd | Optical fibre diffraction grating sensor |
US5426297A (en) * | 1993-09-27 | 1995-06-20 | United Technologies Corporation | Multiplexed Bragg grating sensors |
US5451772A (en) * | 1994-01-13 | 1995-09-19 | Mechanical Technology Incorporated | Distributed fiber optic sensor |
US5748312A (en) * | 1995-09-19 | 1998-05-05 | United States Of American As Represented By The Secretary Of The Navy | Sensing apparatus and method for detecting strain between fiber bragg grating sensors inscribed into an optical fiber |
GB2317008B (en) * | 1996-09-06 | 2000-02-02 | British Aerospace | A fibre optic interferometric strain gauge assembly |
US5828059A (en) * | 1996-09-09 | 1998-10-27 | Udd; Eric | Transverse strain measurements using fiber optic grating based sensors |
US6072567A (en) * | 1997-02-12 | 2000-06-06 | Cidra Corporation | Vertical seismic profiling system having vertical seismic profiling optical signal processing equipment and fiber Bragg grafting optical sensors |
US5987197A (en) * | 1997-11-07 | 1999-11-16 | Cidra Corporation | Array topologies for implementing serial fiber Bragg grating interferometer arrays |
-
1999
- 1999-03-19 GB GB9906361A patent/GB2348000B/en not_active Expired - Fee Related
-
2000
- 2000-03-17 AU AU33058/00A patent/AU3305800A/en not_active Abandoned
- 2000-03-17 WO PCT/GB2000/000994 patent/WO2000057148A1/en active IP Right Grant
- 2000-03-17 US US09/936,551 patent/US6816638B1/en not_active Expired - Fee Related
- 2000-03-17 EP EP00911061A patent/EP1183510B1/en not_active Expired - Lifetime
- 2000-03-17 CA CA002366557A patent/CA2366557A1/en not_active Abandoned
- 2000-03-17 DE DE60014631T patent/DE60014631T2/en not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0216565A2 (en) * | 1985-09-10 | 1987-04-01 | Gec-Marconi Limited | Improvements relating to optical devices |
US5680489A (en) * | 1996-06-28 | 1997-10-21 | The United States Of America As Represented By The Secretary Of The Navy | Optical sensor system utilizing bragg grating sensors |
Non-Patent Citations (1)
Title |
---|
PUTNAM M A ET AL: "BROADBAND SQUARE-PULSE OPERATION OF A PASIVELY MODE-LOCKED FIBER LASTER FOR FIBER BRAGG GRATING INTERROGATION", OPTICS LETTERS,US,OPTICAL SOCIETY OF AMERICA, WASHINGTON, vol. 23, no. 2, 15 January 1998 (1998-01-15), pages 138 - 140, XP000733981, ISSN: 0146-9592 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2372322B2 (en) † | 2010-04-01 | 2023-08-09 | Koninklijke BAM Groep N.V. | System and method for determining the axle load of a vehicle and a sensor device |
Also Published As
Publication number | Publication date |
---|---|
AU3305800A (en) | 2000-10-09 |
EP1183510A1 (en) | 2002-03-06 |
GB2348000A (en) | 2000-09-20 |
US6816638B1 (en) | 2004-11-09 |
DE60014631T2 (en) | 2006-03-02 |
GB2348000B (en) | 2001-02-07 |
DE60014631D1 (en) | 2004-11-11 |
CA2366557A1 (en) | 2000-09-28 |
EP1183510B1 (en) | 2004-10-06 |
GB9906361D0 (en) | 1999-05-12 |
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