CN1683903A - Method for simultaneously measuring bending curvature and bending direction - Google Patents
Method for simultaneously measuring bending curvature and bending direction Download PDFInfo
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- CN1683903A CN1683903A CN 200510024425 CN200510024425A CN1683903A CN 1683903 A CN1683903 A CN 1683903A CN 200510024425 CN200510024425 CN 200510024425 CN 200510024425 A CN200510024425 A CN 200510024425A CN 1683903 A CN1683903 A CN 1683903A
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Abstract
The simultaneous measurement method of bending curvature and bending direction includes first measuring long period fiber grating bending characteristic and drawing the bending sensitivity curve of resonance wavelength of long period fiber grating LPFGA and LPFGB vs circumferential direction in 360 deg; cascading LPFGA and LPFGB and LPFGC with unimodal fibers and embedding into the measured engineering structure; measuring variation in resonance wavelength; calculating bending curvature; and judging the bending direction of the measured engineering structure based on the variation in LPFGA and LPFGB resonance wavelength and the bending curvature and through comparison with the bending sensitivity curve. The present invention realizes the simultaneous measurement method of bending curvature and bending direction of engineering structure, and the sensor is small, low in cost, compatible with fiber and easy in embedding into the measured engineering structure.
Description
Technical field
The present invention relates to a kind of measuring method of technical field of optical fiber sensing, measuring method when specifically being a kind of bending curvature and bending direction.
Background technology
Long period fiber grating (long period fiber grating:LPFG) is a kind of optical fiber passive bandreject filtering device that just occurred in recent years.Long period fiber grating has without male offspring to reflection, be compatible with optical fiber entirely, volume is little, can imbed advantage such as intellectual material and have in some aspects than the better sensing characteristics of Fiber Bragg Grating FBG.Therefore, long period fiber grating is from once occurring having obtained widespread use at sensory field of optic fibre.The resonance wavelength of the long period fiber grating that ultraviolet light writes in ordinary optic fibre is linear change with the increase of bending curvature.Therefore, this long period fiber grating is a bend sensor preferably.Because the crooked sensitivity of the resonance wavelength of the differently curved direction of long period fiber grating that ultraviolet light commonly used writes much at one, therefore general long period fiber grating bend sensor can only be measured bending curvature and can not differentiate bending direction.Yet, to measure in the application in many practical project, the size but also the needs that not only need sometimes to measure amount of bow are differentiated bending direction.Therefore, not only energy measurement amount of bow but also the bend sensor that can differentiate bending direction (particularly differentiating any bending direction in 360 ° of scopes) have important practical significance to the practical problems that solves engineering survey.High frequency CO
2Laser pulse can write high-quality LPFG in high-efficiency and low-cost ground in ordinary optic fibre, because CO
2Single survey incident of laser causes grating xsect index distribution inhomogeneous, thereby makes it may have the characteristic of many uniquenesses.
Find by prior art documents, people such as Patrick H J are at " Electronics Lett. " 1998,34 (18), " the Long period fibre gratings for structural bendsensing " that delivers on the 1773-1774, (" electronics wall bulletin " long period fiber grating crooked sensory).Mention in this article that carrying two LPFG with certain bending direction correlativity that write in the optical fiber with ultraviolet light at hydrogen cooperatively interacts and can solve engineering survey to a certain extent and not only need to measure the size of amount of bow but also the problem of needs differentiation bending direction in using.But this method can only realize can not realizing the differentiation of two symmetric curvature directions (promptly be bent upwards or be bent downwardly) differentiation to any bending direction.In further retrieving, do not find when measuring the engineering structure bending curvature, to judge the bibliographical information of any bending direction as yet.
Summary of the invention
The objective of the invention is to deficiency, measuring method when having proposed a kind of bending curvature and bending direction at existing fiber crooked sensory technology.This method can not only be measured amount of bow and can differentiate bending direction arbitrarily, overcome the deficiency that existing other bend sensor can only be measured bending curvature or can only differentiate the bending direction of two symmetries at the most, thus the real real-time monitoring that realizes engineering structure.
The present invention is achieved by the following technical solutions, comprises following five steps:
(1) measure the long period fiber grating flexural property:
At first build the device of measuring the long period fiber grating flexural property, measure high frequency CO with this flexural property measurement mechanism then
2Two long period fiber grating LPFG that laser pulse writes
AAnd LPFG
BAnd long period fiber grating LPFG who writes with ultraviolet light
CFlexural property, mainly be to measure the crooked sensitivity of its resonance wavelength and amplitude to differently curved direction.With the graphing method LPFG that draws
AAnd LPFG
BResonance wavelength to the crooked sensitivity curve of different circumference bending directions in 360 ° of scopes of circumference.
High frequency CO
2The flexural property of the long period fiber grating that laser pulse writes has tangible bending direction correlativity, crooked sensitivity for each bending direction grating resonance wavelength and amplitude is different, and in 360 ° of scopes of circumference, exist two resonance wavelengths and amplitude to the most responsive direction of bending and two resonance wavelength and the amplitude direction least responsive to bending, the resonance wavelength of the long period fiber grating that ultraviolet light writes is linear change with the increase of bending curvature, and the sensitivity of each bending direction is identical.
(2) grating cascade:
The LPFG that records flexural property
AAnd LPFG
BAnd LPFG
CWith the mutual cascade of single-mode fiber, and imbed tested engineering structure.Make LPFG during the grating cascade
AAnd LPFG
BResonance wavelength the sensitive direction of bending is intersected 45 ° of angles and LPFG mutually
CBe in LPFG
AAnd LPFG
BBetween.Should make grating be in free relaxed state when imbedding, bending strain is not arranged.
3) measuring resonance wavelength changes:
As input, monitor the variation of three Resonant Wavelengths of Long Period Fiber Gratings with the width light source in real time with spectrometer.Measure the variation of a certain moment three Resonant Wavelengths of Long Period Fiber Gratings.
(4) calculate bending curvature:
According to LPFG
CThe variation of resonance wavelength and crooked Calculation of Sensitivity thereof go out the size of tested engineering structure bending curvature.
(5) differentiate bending direction:
According to the LPFG that records
AAnd LPFG
BThe size of the variation of resonance wavelength and (4) bending curvature that calculates of step, and contrast the bending direction that crooked sensitivity curve that (1) step drew can be judged tested engineering structure.
The inventive method has solved the decision problem of the bending direction in the flexural measurement simultaneously, overcome the deficiency that other bend sensor can only be measured bending curvature or can only differentiate the bending direction of two symmetries at the most, with long period fiber grating as sensing element, volume is little, cost is low, be compatible with optical fiber entirely, can easily imbed this structure of tested engineering, can realize real-time monitoring, form so-called intelligence structure engineering structure.Therefore, the present invention is expected to obtain to use widely at sensory field of optic fibre.
Description of drawings
The schematic diagram of measuring method when Fig. 1 is bending curvature and bending direction
Wherein: (a) connected mode of long period fiber grating, (b) embedded mode of long period fiber grating.
Fig. 2 is the flexural property instrumentation plan of long period fiber grating
Fig. 3 high frequency CO
2Curve map when the different circumferencial directions of the long period fiber grating that laser pulse writes are crooked
Wherein: (a) variation of resonance wavelength, (b) variation of loss peak amplitude.
Fig. 4 is along with the increase of different circumferencial direction bending curvatures, high frequency CO
2The curve map of the long period fiber grating that laser pulse writes
Wherein: (a) variation of resonance wavelength, (b) variation of loss peak amplitude;
(a) LPFG that Fig. 5 represents with sinusoidal curve
A(b) LPFG
BThe directional correlation linearity curve of the crooked sensitivity of resonance wavelength, wherein the curve of (b) expression is obtained for 45 ° to the translation of negative axle by the curve of (a) expression.
Embodiment
For understanding technical scheme of the present invention better, be further described below in conjunction with accompanying drawing and specific embodiment.
The schematic diagram of measuring method as shown in Figure 1 in the time of bending curvature proposed by the invention and bending direction.This scheme mainly is based on high frequency CO
2The flexural property of the long period fiber grating that laser pulse writes has tangible bending direction correlativity and proposes.The measuring process of instantiation is as follows:
(1) measures the crooked sensitivity of the resonance wavelength of long period fiber grating and loss peak amplitude with flexural property measurement mechanism shown in Figure 2 to the different directions bending.LPFG represents tested long period fiber grating; P represents applied pressure; The length that l represents crooked optical fiber (grating) promptly about distance between two fulcrums; H is the amount of bow of the x=l/2 place optical fiber (grating) read of micrometer caliper; X-o-y coordinate representation is the coordinate system that initial point is set up with the left fulcrum of crooked steel ruler.
The optical fiber at long period fiber grating two ends is held on two supports that spacing is l, and makes long period fiber grating be positioned at the central authorities of two supports, elasticity preferably steel ruler be pressed on the optical fiber.Smooth thin rubber cushion is glued to the rack surface that contacts with steel ruler, thereby prevents that steel ruler from pressing crisp optical fiber and the optical fiber at long period fiber grating two ends can be moved axially, in order to avoid long period fiber grating produces the axial tension strain when crooked.The optical fiber at long period fiber grating two ends is pasted on the surface of two banking stops respectively and banking stop is inserted the fluting of index plate and makes optical fiber be in the center of circle of index plate.The effect of banking stop makes optical fiber rotate synchronously around axis when being the index plate rotation on the one hand, when making fibre-optical bending again on the other hand small moving axially can be arranged.Thereby the index plate that rotates both sides synchronously drives optical fiber and rotates the flexural property of measuring the different circumferencial directions of long period fiber grating.The counterweight that hangs 5g on the index plate outer fibers makes optical fiber be in tensioned state all the time, so that long period fiber grating is close to the lower surface of steel ruler, but is unlikely to produce bigger axial strain.Wideband light source (SLED1550S5A) is as the input of long period fiber grating, and spectroanalysis instrument (HP86140A) is measured the variation of grating transmission spectrum.Utilizing micrometer caliper to exert pressure in steel ruler central authorities bends long period fiber grating.Left fulcrum with crooked steel ruler in Fig. 2 is that initial point is set up the xoy coordinate system.According to the relevant knowledge of the mechanics of materials, the bending curvature C of long period fiber grating can be expressed as:
Y is the amount of bow of corresponding x place steel ruler (optical fiber) among Fig. 2 in the formula, and y ' is a first order derivative, y, and " be second derivative, H is the amount of bow of the x=l/2 place optical fiber (grating) read of micrometer caliper, and l=150mm is the length of the optical fiber (grating) that is bent.
At first long period fiber grating is done the directional dependency experiment of flexural property.Tested long period fiber grating is for using high frequency CO
2Laser pulse has write resonance wavelength=1531.4nm in Corning SMF-28 optical fiber, the loss peak amplitude is the long period fiber grating of A=-15.391dB.CO
2The one-sided incident of laser causes the xsect index distribution of the long period fiber grating that this method writes unbalanced, so that it may have the characteristic of many uniquenesses.Steel ruler is taken out in each experiment earlier, rotates the index plate of the right and left clockwise synchronously, so that long period fiber grating is rotated 18 ° around axis, then steel ruler is pressed on the optical fiber.The adjustable screw mircrometer gauge makes crooked 2.5mm (the curvature C=1.3m of grating
-1), with the resonance wavelength of spectrometer test long period fiber grating loss peak and the variation of amplitude.Read one time number after being pressed on the optical fiber to steel ruler at every turn, the adjustable screw mircrometer gauge is read number one time after reaching and specifying amount of bow again, the resonance wavelength of the long period fiber grating loss peak that bending causes and amplitude be changed to the poor of twice reading, thereby eliminate the influence to Resonant Wavelengths of Long Period Fiber Gratings or loss peak amplitude such as the operation of rotating optical fiber and mobile steel ruler.Each long period fiber grating is rotated 18 ° around axis and is just tested the first order buckling characteristic, continues the once flexural property of different circumferencial directions of progressively rotating shutter one all repeated tests behind the flexural property of having surveyed 360 ° of scopes of long period fiber grating circumference again.
This long period fiber grating is to circumference different directions bending (curvature 1.3m
-1) time resonance wavelength and loss peak amplitude variation respectively as Fig. 3 (a) with (b), 0 ° of direction of horizontal ordinate is a circumferencial direction of getting at random, provided the test result of rotating for two weeks among the figure, and the plots changes in the curve in 0 °～360 ° scopes and 360 °～720 ° scopes is about the same, this shows that the directional dependency of measuring the flexural property of long period fiber grating with this device is feasible, and experimental result is reliable.As shown in Figure 3, high frequency CO
2The flexural property of the resonance wavelength of the long period fiber grating that laser pulse writes and loss peak amplitude has stronger bending direction correlativity---and resonance wavelength and loss peak amplitude are responsive to the bend ratio of some circumferencial direction, and to the bend-insensitive of other circumferencial directions, and in 360 ° of scopes of circumference, exist two resonance wavelengths or loss peak amplitude to the most responsive direction of bending and two resonance wavelength or the loss peak amplitude direction least responsive to bending.
Do the experiment that bending curvature increases gradually once more respectively corresponding to the several special circumference bending direction among Fig. 3 (the most responsive and least responsive direction).Having provided bending curvature among the figure is 1.3m
-1The time bending direction change two weeks, 0 °～720 ° test result.Experimental result as shown in Figure 4, ◆ expression circumference 234 ° of directions, total amount of bow H=2.7mm; ■ represents 36 ° of directions of circumference, total amount of bow H=3.9mm; 144 ° of directions of ▲ expression circumference, total amount of bow H=4.5mm, (a) resonance wavelength, (b) loss peak amplitude, horizontal ordinate is that amount of bow increases progressively Δ H=0.3mm at every turn by the curvature C of the corresponding amount of bow H of formula (1) calculating among the figure.By Fig. 3 and Fig. 4 as can be known, on the long period fiber grating circumferencial direction the most responsive to bending (36 ° and 234 °), resonance wavelength is moved with the increase approximately linear ' indigo plant ' of bending curvature, and sensitivity is about-6.4nm/m
-1, and at C≤4.0m
-1Scope internal linear degree is better.The loss peak amplitude reduces with the increase approximately linear of bending curvature, and sensitivity is about 6.2dB/m
-1, and at C≤2.0m
-1Scope internal linear degree is also better, but along with the increase loss peak amplitude sensitivity of curvature has the trend that reduces.On the circumferencial direction (144 °) of long period fiber grating, if the not too big (C≤1.0m of bending curvature to bend-insensitive
-1), then along with the increase of bending curvature, resonance wavelength and loss peak amplitude are almost constant, and maximum the variation is about respectively-0.05nm and 0.2dB; But when bending curvature was big, resonance wavelength and amplitude had certain variation.
Select two high frequency CO similarly
2The resonance wavelength that laser writes is respectively λ
AAnd λ
BLong period fiber grating (LPFG
AAnd LPFG
B) and the resonance wavelength that writes of ultraviolet light be λ
CThe long period fiber grating (LPFG that does not have the bending direction correlativity
C), attention should make λ
A≠ λ
B≠ λ
CAnd it is overlapping so that guarantee that the loss peak of three gratings in the flexural measurement process does not have to differ greatly.Accurately test LPFG with flexural property measurement mechanism shown in Figure 2
AAnd LPFG
BThe crooked sensitivity of resonance wavelength directional dependency and the minimum and maximum direction of sensitivity made mark, and with this device to test LPFG
CThe crooked sensitivity k of resonance wavelength
C
(2) grating cascade: use single-mode fiber as shown in Figure 1 LPFG
A, LPFG
BAnd LPFG
CCascade is also imbedded the surface of tested engineering structure.Wideband light source is as input among Fig. 1 (a), the resonance wavelength of three long period fiber grating when the spectrometer measurement engineering structure is crooked
A, λ
BAnd λ
CVariation.Fig. 1 (b) is for imbedding the cross sectional representation of long period fiber grating, in order to represent to know that the ratio of grating is exaggerated among the figure.LPFG
AAnd LPFG
BRepresent high frequency CO respectively
2The flexural property that laser pulse writes has the long period fiber grating of bending direction correlativity; LPFG
CThe flexural property that the expression ultraviolet light writes does not have the long period fiber grating of bending direction correlativity; Max and min represent LPFG respectively
AAnd LPFG
BThe minimum and maximum direction of crooked sensitivity of resonance wavelength, promptly the most responsive and least responsive direction.Should make LPFG when imbedding long period fiber grating
AAnd LPFG
BResonance wavelength, preferably intersects with 45 ° of angles, shown in Fig. 1 (b) not in same direction the sensitive direction of bending.Long period fiber grating bending direction correlativity by the front is tested as can be known high frequency CO
2The directional correlation linearity curve of the crooked sensitivity of the resonance wavelength of the long period fiber grating that laser pulse writes is similar to sinusoidal curve, and in 360 ° of scopes of circumference, there are two cycles, the LPFG that is without loss of generality and imbeds and mark with among the sinusoidal curve approximate representation that has two cycles in 0 ° of-360 ° of scope shown in Figure 5 such as Fig. 1 (b)
AAnd LPFG
BThe directional correlation linearity curve of the crooked sensitivity of resonance wavelength.(a) expression LPFG among Fig. 5
A, (b) expression LPFG
B, horizontal ordinate is represented the circumference bending direction.LPFG in the horizontal ordinate zero degree corresponding diagram 1 (b) among Fig. 5 (a)
ADirection shown in the upside max.Because LPFG among Fig. 1 (b)
BThe direction of the crooked sensitivity maximum of resonance wavelength with respect to LPFG
AThe direction of the crooked sensitivity maximum of resonance wavelength has turned clockwise 45 °, thus the curve among Fig. 5 (b) with respect to the curve among Fig. 5 (a) to 45 ° of negative direction of principal axis translations.
(3) measure: with the spectrometer variation of three long period fiber grating transmission spectrums of monitoring in real time.When tested engineering structure bends because of certain reason, measure LPFG by spectrometer
A, LPFG
BAnd LPFG
CThe variation of resonance wavelength is respectively Δ λ
A, Δ λ
BWith Δ λ
C
(4) calculate bending curvature: by C=Δ λ
C/ k
CObtain LPFG
CBe the bending curvature C of tested engineering structure, then by k
A=Δ λ
A/ C and k
B=Δ λ
B/ C obtains LPFG respectively
AAnd LPFG
BThe crooked sensitivity k of resonance wavelength
AAnd k
B
(5) differentiate bending direction: standardized of with dashed lines is represented sensitivity k respectively in Fig. 5 (a) and Fig. 5 (b)
AAnd k
BStraight line, be respectively α with the intersection point of the directional correlation linearity curve of crooked sensitivity
1, α
2, α
3, α
4And β
1, β
2, β
3, β
4As sensitivity k
AAnd k
BFor maximum or hour, represent k
AAnd k
BStraight line and the intersection point of the directional correlation linearity curve of crooked sensitivity have only two intersection points respectively, but this does not influence generality discussed below.By Fig. 5 (a) as can be known, LPFG
AThe crooked sensitivity k of resonance wavelength
ACorresponding bending direction may be α
1, α
2, α
3Or α
4By Fig. 5 (b) as can be known, LPFG
BThe crooked sensitivity k of resonance wavelength
BCorresponding bending direction may be β
1, β
2, β
3Or β
4But actual bending direction has only one, so satisfy | and α
i-α
j| the α of=min ≈ 0 (i, j=1,2,3,4)
i(β
j) pairing direction is exactly real bending direction.As shown in Figure 5, for (a) shown in the figure and (b) the most special situation of two bending direction correlativity curves identical (only being the translation certain angle), satisfy | α
i-β
j| the direction of=min has two α
2(β
1) and α
4(β
3), promptly | α
2-β
1|=| α
4-β
3|=0.Yet, the actual high frequency CO of using
2Laser pulse writes LPFG
AAnd LPFG
BThe time, because parameters such as the cycle of each grating that is provided with, periodicity, laser frequency, laser energy, time shutter are different and the resonance wavelength of consideration
AAnd λ
BAlso inequality, so LPFG
AAnd LPFG
BResonance wavelength
AAnd λ
BThe directional correlation linearity curve of crooked sensitivity certainly can not be in full accord, neither strict sinusoidal curve, and the difference of two curves is generally bigger.So, satisfy among the Fig. 5 that obtains with graphing method by above step | α
i-β
j| the direction of=min has and only has one, promptly real bending direction.In Fig. 5 of the directional dependency curve representation of using actual crooked sensitivity,, therefore approximate the k of maximum or minimum sensitivity because the directional correlation linearity curve is not strict sinusoidal curve
AAnd k
BThe intersection point of the straight line of representative and directional correlation linearity curve may have only one, two or three (having four at most) respectively.
When imbedding long period fiber grating, make LPFG
AAnd LPFG
BThe purpose that the most responsive direction of resonance wavelength bending intersects with 45 ° angle is LPFG when making engineering structure crooked
AAnd LPFG
BThe crooked sensitivity k of resonance wavelength
AAnd k
BBetween difference big as far as possible so that obtain bending direction with above-mentioned graphing method more accurately.Differentiate the precision and the LPFG of bending direction with above-mentioned sensing scheme
AAnd LPFG
BThe precision of the directional correlation linearity curve of the crooked sensitivity of resonance wavelength is closely related.Therefore, describing LPFG
AAnd LPFG
BShould be accurate as far as possible during the directional correlation linearity curve of the crooked sensitivity of resonance wavelength.LPFG in actual applications
CAlso available resonance wavelength and bending curvature have the Fiber Bragg Grating FBG of better linear relationship to replace, and it is identical with the step of differentiating bending direction that remaining measures sensitivity.
Claims (4)
1, measuring method a kind of bending curvature and bending direction the time is characterized in that concrete steps are as follows:
(1) measures the long period fiber grating flexural property: at first build the device of measuring the long period fiber grating flexural property, use this measurement device high frequency CO then
2Two long period fiber grating LPFG that laser pulse writes
AAnd LPFG
BAnd long period fiber grating LPFG who writes with ultraviolet light
CFlexural property, measure the crooked sensitivity of its resonance wavelength and amplitude, with the graphing method LPFG that draws to bending direction
AAnd LPFG
BResonance wavelength to the crooked sensitivity curve of each circumference bending direction in 360 ° of scopes of circumference;
(2) grating cascade: the LPFG that records flexural property
A, LPFG
BAnd LPFG
CWith the mutual cascade of single-mode fiber, and imbed tested engineering structure;
(3) measuring resonance wavelength changes: use the width light source as input, with the spectrometer variation of three Resonant Wavelengths of Long Period Fiber Gratings of monitoring in real time, the variation of measuring a certain moment three Resonant Wavelengths of Long Period Fiber Gratings;
(4) calculate bending curvature: according to LPFG
CThe variation of resonance wavelength and crooked Calculation of Sensitivity thereof go out the size of tested engineering structure bending curvature;
(5) differentiate bending direction: according to the LPFG that records
AAnd LPFG
BThe size of the variation of resonance wavelength and (4) bending curvature that calculates of step, and contrast the bending direction that crooked sensitivity curve that (1) step drew is judged tested engineering structure.
2, measuring method bending curvature according to claim 1 and bending direction the time is characterized in that, in the step (1), and high frequency CO
2The flexural property of the long period fiber grating that laser pulse writes has tangible bending direction correlativity---and the crooked sensitivity for each bending direction grating resonance wavelength and amplitude is different, and in circumference 360 scopes, exist two resonance wavelengths and amplitude to the most responsive direction of bending and two resonance wavelength and the amplitude direction least responsive to bending, the resonance wavelength of the long period fiber grating that ultraviolet light writes is linear change with the increase of bending curvature, and the sensitivity of each bending direction is identical.
3, measuring method bending curvature according to claim 1 and bending direction the time is characterized in that, in the step (2), should make grating be in free relaxed state when grating is imbedded, and has avoided bending strain.
4, measuring method bending curvature according to claim 1 and bending direction the time is characterized in that, in the step (2), uses the single-mode fiber cascade between the grating, wherein LPFG
AAnd LPFG
BResonance wavelength the sensitive direction of bending is intersected 45 ° of angles and LPFG mutually
CBe in LPFG
AAnd LPFG
BBetween.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102109395A (en) * | 2010-04-27 | 2011-06-29 | 南京航空航天大学 | Monitoring method for LPFG (Long Period Fiber Grating) transverse load direction characteristic and pavement pressure sensor |
| CN103123254A (en) * | 2013-02-07 | 2013-05-29 | 南开大学 | Two-dimensional bending vector sensor based on fiber grating interference structure |
| CN104330032A (en) * | 2014-07-09 | 2015-02-04 | 国家电网公司 | Fiber displacement sensor, fiber displacement detection device and fiber for sensor |
| CN105423953A (en) * | 2015-12-23 | 2016-03-23 | 中国计量学院 | Embedded spherical structure long-period fiber grating curvature sensor |
| CN105928469A (en) * | 2016-06-07 | 2016-09-07 | 华中科技大学 | High-sensitivity fiber curvature sensor capable of discriminating bending direction and free of cross temperature sensitivity |
| CN109000687A (en) * | 2018-07-19 | 2018-12-14 | 西南交通大学 | A kind of curvature demodulating equipment and its method based on core shift phase-shifted fiber grating |
| CN110940292A (en) * | 2019-12-31 | 2020-03-31 | 大连博瑞鑫科技有限公司 | Fiber bragg grating buckling monitoring sensor and preparation method thereof |
| CN113156573A (en) * | 2021-03-29 | 2021-07-23 | 江苏大学 | Orthogonal long-period fiber grating and application thereof in sensing bending |
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2005
- 2005-03-17 CN CN 200510024425 patent/CN1289893C/en not_active Expired - Fee Related
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102109395A (en) * | 2010-04-27 | 2011-06-29 | 南京航空航天大学 | Monitoring method for LPFG (Long Period Fiber Grating) transverse load direction characteristic and pavement pressure sensor |
| CN102109395B (en) * | 2010-04-27 | 2012-09-05 | 南京航空航天大学 | Monitoring method for LPFG (Long Period Fiber Grating) transverse load direction characteristic |
| CN103123254A (en) * | 2013-02-07 | 2013-05-29 | 南开大学 | Two-dimensional bending vector sensor based on fiber grating interference structure |
| CN103123254B (en) * | 2013-02-07 | 2015-05-27 | 南开大学 | Two-dimensional bending vector sensor based on fiber grating interference structure |
| CN104330032A (en) * | 2014-07-09 | 2015-02-04 | 国家电网公司 | Fiber displacement sensor, fiber displacement detection device and fiber for sensor |
| CN105423953A (en) * | 2015-12-23 | 2016-03-23 | 中国计量学院 | Embedded spherical structure long-period fiber grating curvature sensor |
| CN105928469A (en) * | 2016-06-07 | 2016-09-07 | 华中科技大学 | High-sensitivity fiber curvature sensor capable of discriminating bending direction and free of cross temperature sensitivity |
| CN105928469B (en) * | 2016-06-07 | 2019-01-04 | 华中科技大学 | It is a kind of it is highly sensitive differentiate bending direction without the sensitive Curvature Optical Fiber Sensor of Temperature cross-over |
| CN109000687A (en) * | 2018-07-19 | 2018-12-14 | 西南交通大学 | A kind of curvature demodulating equipment and its method based on core shift phase-shifted fiber grating |
| CN109000687B (en) * | 2018-07-19 | 2021-01-01 | 西南交通大学 | Curvature demodulation device and method based on core-shift phase-shift fiber grating |
| CN110940292A (en) * | 2019-12-31 | 2020-03-31 | 大连博瑞鑫科技有限公司 | Fiber bragg grating buckling monitoring sensor and preparation method thereof |
| CN113156573A (en) * | 2021-03-29 | 2021-07-23 | 江苏大学 | Orthogonal long-period fiber grating and application thereof in sensing bending |
| CN113156573B (en) * | 2021-03-29 | 2023-02-17 | 江苏大学 | Orthogonal long-period fiber grating and application thereof in sensing bending |
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