CN103674079B - Based on the method for real-time measurement of fiber Bragg grating sensor measuring system - Google Patents
Based on the method for real-time measurement of fiber Bragg grating sensor measuring system Download PDFInfo
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Abstract
The present invention is the method for real-time measurement based on fiber Bragg grating sensor measuring system, and system for use in carrying comprises tunable laser source, optical splitter, host computer, a light power meter and n fiber-optic grating sensor.The step of this method for real-time measurement is: I, experiment obtains the calibrating parameters of the linear relation between each fiber Bragg grating sensor centre wavelength and the measured physical quantity of demarcation; II, the reference data table of n fiber-optic grating sensor is generated; III, the physical parameter of the corresponding test point of each fiber-optic grating sensor is surveyed.This law PC control LASER Light Source first carries out reference scan to each FBG, obtain the reference data table of each FBG, first specific wavelength is exported successively by table during actual measurement, measure reflected optical power, adjust specific output wavelength according to reference data table thus and calculate the side-play amount of each FBG centre wavelength and carry out demodulation.Measuring speed improves greatly, ensures to measure real-time; Measuring accuracy is high, can detect and be low to moderate physical quantity variation corresponding to 0.1pm wavelength shift.
Description
(1) technical field
The present invention relates to field of photodetection, be specially a kind of method for real-time measurement based on fiber Bragg grating sensor measuring system.
(2) background technology
The method for making of fiber grating maturation has greatly promoted the development of fiber grating application technology, makes fiber grating become one of the most rising passive device.It is typically applied is fiber-optic grating sensor, there is electrical insulating property good, electromagnetism interference (EMI) and anti-Radio frequency interference (RFI) (RFI) ability strong, stable chemical performance, corrosion-resistant, the characteristics such as volume is little, lightweight, and loss is little, capacity is large, and version is flexible, sensitivity is high, therefore the optical fiber grating sensing network that the many reference amounts such as its stress formed, strain, temperature and vibration detect has outstanding advantage, replace traditional sensors just gradually and become the main force of sensor family.
Fiber Bragg Grating FBG (FiberBraggGrating, be abbreviated as FBG) be the light sensitive characteristic utilizing fiber optic materials, in a segment limit of bare fibre, the in-core body grating with periodic refractive index is write with certain Writing Technology, its Essential Action is the narrow band optical filter formed in fibre core centered by resonant wavelength, wideband light source or tunable optical source export light through grating, narrow-band spectrum in spectrum centered by the Bragg wavelength of grating is demodulated by reflecting at grating place, and other most of light will transmission occur and transmit along original direction.Fiber grating fibre core is under the effect of ambient temperature, stress and so on physical quantities, and refractive index will change, thus causes optical grating reflection center wavelength of light to drift about.This characteristic is the principle of work of fiber Bragg grating sensor, can be drawn the change of environment measured physical quantity residing for fiber-optic grating sensor by the change of detection of reflected optical wavelength.
At present, Optical Fiber Sensor Measurement System light source adopts broad band laser light source or continuously adjustable LASER Light Source.The Optical Fiber Sensor Measurement System disadvantage of broad band laser light source is adopted to be that the optical power density that light source exports is low, useful power is only below its per mille exporting general power, thus, the Fibre Optical Sensor of this system can only use in short range, and measurement is counted less.Comply with the future development trend of Optical Fiber Sensor Measurement System towards wavelength-division multiplex and optical fiber sensor network, Optical Fiber Sensor Measurement System adopts tunable laser source, improves power and resolution.But tunable laser source mainly adopts continuous sweep mode at present, the Partial Power only having corresponding Fibre Optical Sensor to set wavelength (or frequency) is applied, and therefore laser power utilizes insufficient, and measuring speed is limited, and its resolution also has much room for improvement.
(2) summary of the invention
The object of this invention is to provide a kind of method for real-time measurement based on fiber Bragg grating sensor measuring system, in the Optical Fiber Sensor Measurement System of tunable laser source, adopt wavelength-division multiplex method, improve measuring speed and resolution.
The present invention devises the method for real-time measurement based on fiber Bragg grating sensor measuring system, and what this method was used comprises tunable laser source, optical splitter, host computer, a light power meter and n fiber-optic grating sensor based on Bragg optical-fiber grating sensor measuring system.Described fiber-optic grating sensor is fiber Bragg grating sensor (FiberBraggGratingSensor, FBG).Host computer connection control tunable laser source and light power meter, tunable laser source connects a three-dB coupler, laser inputs from a point of optical port of three-dB coupler, arrive n the fiber-optic grating sensor that it closes road port serial connection, and n is the integer of 1 ~ 120.Another point of optical port of three-dB coupler is connected to light power meter, the reflected optical power of n fiber-optic grating sensor of terminal series connection is closed in order to catch this three-dB coupler, and the synchronous triggering input port of power meter connects the synchronous triggering delivery outlet of tunable laser source, makes power meter image data change synchronous with optical source wavelength.
Each fiber-optic grating sensor has certain wavelength response range, and its reflectance spectrum is emergent power reflection at peak within the scope of this, the peak value P of power
maxcorresponding wavelength is called central wavelength lambda
c, be also this fiber grating sensor wavelength, the crest residing for power peak is main mould.Meanwhile, the peak power of adjacent with the main mould most flash mould of definition is main mould bottom power P
min, the power P of main mould crest both sides spectral line
minthe difference of the wavelength that place is corresponding is the bandwidth λ of this fiber-optic grating sensor reflectance spectrum
bW.
When the temperature of fiber-optic grating sensor surrounding outer environment, stress and so on physical quantities change, the effective refractive index of fibre core grating or cycle will be made to change thereupon, therefore reflectance spectrum is at certain scope bias internal, center sensor wavelength shift, by detecting the change of each fiber-optic grating sensor reflectance spectrum, therefrom demodulation the change of extraneous specific physical quantity can be obtained.The operating wavelength range of n fiber-optic grating sensor of series connection is without juxtaposition, and namely their reflectance spectrum deviation range is all not identical.According to extraneous test condition, delimit the operating wavelength range of n fiber-optic grating sensor, and in the wavelength coverage that covers of the tunable laser source that the operating wavelength range of each fiber-optic grating sensor all belongs to native system use.
As the bandwidth λ of the reflectance spectrum of n fiber-optic grating sensor
bWequal, the dynamic range of its measure physical quantities is also equal simultaneously, and namely reflectance spectrum offset Δ λ is equal, and on the basis ensureing each sensor reflectance spectrum waveform integrality, the quantity n of fiber-optic grating sensor meets:
n<(λ
ALL-λ
BW)/Δλ
Wherein, λ
aLLfor the scanning wavelength total bandwidth of native system tunable laser source used.The center wavelength shift amount Δ λ of each fiber-optic grating sensor is larger, the dynamic range of the physical quantity of test is larger, but multiplexing fiber-optic grating sensor quantity n will reduce, therefore should according to actual conditions reasonable distribution number of sensors and measurement dynamic range.
Each fiber-optic grating sensor pair input light reflectance same with wherein cardiac wave appearance is 80 ~ 90%.
The job step based on fiber Bragg grating sensor measuring system method for real-time measurement of the present invention's design is as follows:
I, experiment obtains the calibrating parameters of the linear relation between each fiber Bragg grating sensor centre wavelength and the measured physical quantity of demarcation
The spectral shift amount of fiber-optic grating sensor is all considered as linear relation from different physical parameter, but the slope difference in linear relation.When the fiber-optic grating sensor that germanium fused quartz optical fiber makes as mixed is for strain measurement, the theoretical relationship between the wave length shift of its fiber grating Bragg sensor and axial strain amount is expressed as:
Δλ=0.78λε
ε is axial strain amount, and in 1550nm window, the response of its axial strain amount is: 1.209pm/ μ ε.
And be used for temperature survey by mixing the fiber-optic grating sensor that germanium fused quartz optical fiber makes, the theoretical relationship of its wavelength shift and temperature variation is expressed as:
Δλ=8.85×10
-6λΔT
Δ T is temperature variation, and in 1550nm window, its temperature-responsive is about: 10pm/ DEG C.
Due to the manufacture craft of fiber Bragg grating sensor and the difference of encapsulating material, each fiber Bragg grating sensor also can be different from the response parameter slope in the linear relation of identical measured physical quantity and intercept.Therefore, need to demarcate the slope in the center wavelength shift amount of each fiber Bragg grating sensor and the linear relation of measured physical quantity and intercept by experiment, just can be obtained the change of measurand by the center wavelength shift demodulation of fiber Bragg grating sensor.
Reference instrument is used to demarcate the different value of measured physical quantity at least three, the centre wavelength of each fiber Bragg grating sensor corresponding under being simultaneously recorded in the measured physical quantity effect of each demarcation, use linear fit method to calculate the linear relation of measured physical quantity and fiber Bragg grating sensor centre wavelength, and record response parameter slope and the values of intercept of this linear equation.
When the making material of the multiple fiber Bragg grating sensors used in measuring system, technique are all identical with packaged type, the response parameter can demarcating one of them fiber Bragg grating sensor is as the common response parameter of each fiber Bragg grating sensor used in measuring system, and the measuring accuracy of this kind of situation is not high.
II, the reference data table of n fiber-optic grating sensor is generated
Before real-time testing in an initial condition, tunable laser source is used to carry out length scanning to n fiber-optic grating sensor, measured the reflectance spectrum distribution situation of n cascaded fiber grating sensor by light power meter, power unit is mw, and a crest represents a fiber-optic grating sensor.I-th main mould peak power of fiber-optic grating sensor reflectance spectrum is P
imax, bottom power is P
imin, i is the sequence number of n fiber-optic grating sensor, i=0,1,2,3 ... n-1.Choose in any side of i-th fiber-optic grating sensor reflectance spectrum main mould crest there is monotonicity one section of spectral line as the reference spectra of this fiber-optic grating sensor, be monotone increasing on the left of main mould crest, right side is monotone decreasing then.The upper extreme point corresponding wavelength of reference spectra is λ
iH, corresponding power is P
iH, its lower extreme point corresponding wavelength is λ
iL, corresponding power is P
iL.The i.e. performance number P of reference spectra upper extreme point
iHmaximum, preferred plan is that P is got in selection
iHbe main mould peak power P
imax90 ~ 95%, the value P of the power of the lower extreme point of reference spectra
iLminimum, preferred plan is that P is got in selection
iLbe main mould bottom power P
imin105 ~ 110%.Wavelength width corresponding to reference spectra is λ
iHand λ
iLthe absolute value of difference, the making characteristic primarily of fiber-optic grating sensor determines.Conveniently calculate, the reference spectra of each fiber-optic grating sensor of native system is all got on the left of main mould crest or is all got right side, thus obtains taking i as the reference data table of sequence, comprises the reflectance spectrum parameter lambda of each fiber-optic grating sensor under original state
iE, λ
i, P
iHand P
iL, wherein λ
ifor the middle wavelength of reference spectra, λ
iassignment is λ for the first time
i=0.5 (λ
iL+ λ
iH); λ
iE=0.5| λ
iH-λ
iL|.In addition, the centre wavelength value λ of reflectance spectrum under this fiber-optic grating sensor original state must also be recorded
iC.
III, the physical parameter of the corresponding test point of each fiber-optic grating sensor is surveyed
According to the wavelength X of n fiber-optic grating sensor in step II gained reference data table
iset the output wavelength of tunable laser source successively, use light power meter to measure the reflected optical power of each fiber-optic grating sensor in real time, record each λ
ithe reflected optical power that corresponding fiber-optic grating sensor is current, and calculate each fiber-optic grating sensor center wavelength shift amount Δ λ
i.Because the operating wavelength range of each sensor is different, namely can judge corresponding fiber-optic grating sensor sequence number according to the output wavelength of LASER Light Source and reflected optical power, and then utilize method of interpolation to calculate the skew of each fiber-optic grating sensor reflectance spectrum by current reflective luminous power and reference table.Demodulation can obtain measured physical quantity corresponding to each sensor place test point according to step I gained each fiber Bragg grating sensor centre wavelength with the linear relation of measured physical quantity, the gradual situation of this measured physical quantity during continuous coverage, can be obtained.Concrete steps are as follows:
I, i=0 is set;
II, the output wavelength arranging tunable laser source are λ
i;
III, measure i-th fiber-optic grating sensor reflected optical power value P by light power meter
iand judge according to i-th fiber-optic grating sensor corresponding power value of step I gained reference data table:
III-1, work as P
iL< P
i< P
iH, perform step IV;
III-2, work as P
i≤ P
iL, the output wavelength of adjustment tunable laser source,
When reference spectra is on the left of main mould crest, λ is set
i=λ
i+ λ
iE,
When reference spectra is on the right side of main mould crest, λ is set
i=λ
i-λ
iE,
Return afterwards and perform step II;
III-3, work as P
i>=P
iH, the output wavelength of adjustment tunable laser source,
When reference spectra is on the left of main mould crest, λ is set
i=λ
i-λ
iE,
When reference spectra is on the right side of main mould crest, λ is set
i=λ
i+ λ
iE,
Return afterwards and perform step II;
IV, computational reflect spectral shift amount, Real-time demodulation measured physical quantity; In step II gained reference data table, method of interpolation is utilized to draw this fiber-optic grating sensor current power value P
icorresponding wavelength value λ
i', by λ
i' with the output wavelength λ of current tunable laser source
icompare, calculate the offset Δ λ of its reflectance spectrum centre wavelength thus
i=λ
i-λ
i', according to i-th fiber-optic grating sensor emission spectrum original state central wavelength lambda that Step II obtains
iCthe emission spectrum centre wavelength calculating current i-th fiber-optic grating sensor is: λ '
iC=λ
iC+ Δ λ
i, and then demodulation obtains the data of temperature or the physical parameter to be measured such as pressure or stress.
V, work as i=n-1, do not receive when ceasing and desisting order and skip to step I, cease and desist order if receive, end of run; As i ≠ n-1, i=i+1 is set, skips to step II.
IV, lasting Real-time demodulation measured physical quantity
Continuous circulation performs step III, measures and continues demodulation to measured physical quantity, the measured physical quantity that real-time follow-up is gradual, cease and desist order, run and stop until receiving the data persistence circulation of n fiber-optic grating sensor.
The advantage that the present invention is based on the method for real-time measurement of fiber Bragg grating sensor measuring system is: 1, PC control tunable laser source first carries out reference scan to each fiber-optic grating sensor, obtain the reference data table of each fiber-optic grating sensor, only need according to wavelength X in the middle of the reference spectra of fiber-optic grating sensor each on this table during actual measurement
iset tunable laser source successively and export specific wavelength, measure the side-play amount of each fiber-optic grating sensor centre wavelength and carry out demodulation, the skew of certain fiber-optic grating sensor reflectance spectrum of each mensuration, scan in whole tuning range without the need to tunable laser source, thus measuring speed is improved greatly, ensure the real-time measured; 2, measuring accuracy is high, can detect and be low to moderate physical quantity variation corresponding to 0.1pm wavelength shift.
(4) accompanying drawing explanation
Fig. 1 is originally based on method for real-time measurement embodiment certain fiber Bragg grating sensor reflected light spectrogram used of fiber Bragg grating sensor measuring system;
Fig. 2 is that this is used based on fiber Bragg grating sensor measuring system structural representation based on the method for real-time measurement embodiment of fiber Bragg grating sensor measuring system;
Fig. 3 is originally based on the process flow diagram of the method for real-time measurement embodiment of fiber Bragg grating sensor measuring system;
Fig. 4 is originally based on the part reflected light spectrogram of method for real-time measurement embodiment 3 fiber Bragg grating sensor original states used of fiber Bragg grating sensor measuring system.
(5) embodiment
As shown in Figure 1, its reflectance spectrum has main mould and Bian Mo to this method for real-time measurement embodiment i-th fiber Bragg grating sensor reflected light spectrogram used based on fiber Bragg grating sensor measuring system.Main mould peak power is P
imax, the wavelength of its correspondence is called the central wavelength lambda of this fiber Bragg grating sensor
iC, be also this fiber grating sensor wavelength.Meanwhile, the peak power of adjacent with the main mould most flash mould of definition is main mould bottom power P
imin, the power P of main mould crest both sides spectral line
iminthe difference of the wavelength that place is corresponding is the bandwidth λ of this fiber-optic grating sensor reflectance spectrum
iBW.
This based on method for real-time measurement embodiment of fiber Bragg grating sensor measuring system used based on fiber Bragg grating sensor measuring system block diagram as shown in Figure 2, comprise tunable laser source, optical splitter, host computer, a light power meter and n fiber-optic grating sensor, in figure, dotted line represents light path.Described fiber-optic grating sensor is fiber Bragg grating sensor (FBG), and the employing of this example is mixed germanium fused quartz optical fiber and made, and for not carry out the naked fine Bragg grating sensor encapsulating, do not add protection tube.Host computer connection control tunable laser source and light power meter, tunable laser source connects a three-dB coupler, and laser inputs from a point of optical port of three-dB coupler, arrive n the fiber-optic grating sensor that it closes road port serial connection.Another point of optical port of three-dB coupler is connected to light power meter, and synchronizing cable connects the synchronous triggering input port of power meter and the synchronous triggering delivery outlet of tunable laser source.
Each fiber-optic grating sensor pair input light reflectance same with wherein cardiac wave appearance is 80 ~ 90%.This example is the method for the strain measurement for steel disc.
The tuning range of this routine tunable laser source is 1524 ~ 1610nm, total bandwidth λ
aLLfor 86nm, suppose that dependent variable scope to be measured is for ± 400 μ ε, the skew λ of so each fiber-optic grating sensor reflectance spectrum
dscope is about ± 0.49nm, and namely the necessary >0.98nm in the centre wavelength interval of each sensor reflectance spectrum, supposes the maximum λ of each sensor
bWfor 0.53nm, so, the number of sensors of series connection must meet n< (λ
aLL-λ
bW)/λ
d, therefore n maximal value is 87.This example gets n=3.
Originally based on fiber Bragg grating sensor measuring system method for real-time measurement embodiment process flow diagram as shown in Figure 3, specific works step is as follows:
I, experiment obtains the calibrating parameters of the linear relation between each fiber Bragg grating sensor centre wavelength and the measured physical quantity of demarcation
In this example, 3 Fiber Bragg Grating FBG (FBG) sensors are walked abreast and is pasted on the middle part of steel disc, one end of steel disc is fixed, steel disc is level, the steel disc other end connects spring clip one end, counterweight is hung at the spring clip other end, counterweight varies in weight, and one end of spring clip suspension counterweight is up and down, spring clip produces tension to steel disc.The state that counterweight is not hung in the setting of this example is original state, and the strain of steel disc is 0.Straingauge pasted by steel disc near FBG sensor, and straingauge connects static resistance strainmeter, can record the electrostrictive strain resistance of steel disc, and obtain the dependent variable of steel disc thus.This example changes the counterweight weight that spring clip hangs, and demarcates three different steel disc strain values, and be recorded in the centre wavelength of each fiber Bragg grating sensor of correspondence under the dependent variable effect of each demarcation, the data obtained is as shown in table 1 simultaneously.The sequence number of this example 3 fiber Bragg grating sensors is i=0,1,2.
The centre wavelength of table 1 each FBG sensor under demarcating steel disc dependent variable
| ε=0 | ε=100με | ε=200με | ε=300με | |
| The centre wavelength (nm) of FBG 0 | 1540.820 | 1540.939 | 1541.055 | 1541.176 |
| The centre wavelength (nm) of FBG 1 | 1546.840 | 1546.960 | 1547.077 | 1547.199 |
| The centre wavelength (nm) of FBG2 | 1552.880 | 1552.977 | 1553.118 | 1553.236 |
According to table 1 the data obtained, use the slope (k) of the linear relation of linear fit method calculating steel disc dependent variable and fiber Bragg grating sensor centre wavelength as follows with intercept (b):
FBG0, slope k
0=0.845 μ ε/pm, intercept b
0=-1301290 μ ε;
FBG1, slope k
1=0.838 μ ε/pm, intercept b
1=-1295434 μ ε;
FBG2, slope k
2=0.841 μ ε/pm, intercept b
2=-1305988 μ ε.
II, the reference data table of 3 fiber-optic grating sensors is generated
Under steel disc one end is without the state hanging counterweight, reference scan is carried out to 3 fiber-optic grating sensors.Use tunable laser source to carry out length scanning to fiber-optic grating sensor, measured the reflectance spectrum distribution situation of 3 cascaded fiber grating sensors by light power meter, power unit is mw, and a crest represents a fiber-optic grating sensor, as shown in Figure 4.This example chooses the one section of spectral line with monotonicity as with reference to spectrum on the left of the reflectance spectrum crest of each FBG sensor, reference spectra upper end performance number P
iHbe 95% of main mould peak power, i.e. P
iH=0.95P
imax, corresponding wavelength is λ
iH; Reference spectra lower power value P
iLbe 105%, i.e. P of main mould waveform bottom power
iL=1.05P
imin, corresponding wavelength λ
iL.Obtain the reference data table of the fiber-optic grating sensor of 3 shown in table 2 thus, comprise the reflectance spectrum parameter lambda of each fiber-optic grating sensor under original state
iC, λ
iE, λ
i, P
iHand P
iL, wherein λ
iE=0.5| λ
iH-λ
iL|, λ
i=0.5 (λ
iH+ λ
iL).
The reference data table of table 2 fiber-optic grating sensor
Counterweight is hung on steel disc connect the free end of spring clip, change counterweight quantity or manually apply stress, measuring the dependent variable of the steel disc of each FBG sensor present position in real time.
According to the wavelength X of 3 fiber-optic grating sensors in step II gained reference data table
iset the output wavelength of tunable laser source successively, use light power meter to measure the reflected optical power of each fiber-optic grating sensor in real time, to each λ
ithe reflected optical power that corresponding fiber-optic grating sensor is current carries out record.Because the bandwidth of operation of each FBG sensor is different, namely corresponding fiber-optic grating sensor sequence number can be judged according to the output wavelength of LASER Light Source and reflected optical power, and then use method of interpolation to be calculated the side-play amount of this fiber-optic grating sensor centre wavelength by current reflective luminous power and reference data table, the i.e. side-play amount of its reflectance spectrum, in conjunction with before the strain measurement coefficient demarcated thus demodulate the current dependent variable of its place test point steel disc.
I, i=0 is set;
II, the output wavelength arranging tunable laser source are λ
i;
III, measure corresponding fiber-optic grating sensor reflected optical power value P by light power meter
iand carry out power judgement according to the data of step I gained reference table:
III-1, work as P
iL< P
i< P
iH, perform step IV.
III-2, work as P
i≤ P
iL, the output wavelength of adjustment light source, arranges λ
i=λ
i+ λ
iE, return and perform step II.
III-3, work as P
i>=P
iH, the output wavelength of adjustment light source, arranges λ
i=λ
i-λ
iE, return and perform step II.
IV, computational reflect spectral shift amount, Real-time demodulation steel disc strain value.In step II gained reference data table, method of interpolation is utilized to draw this fiber-optic grating sensor current power value P
icorresponding wavelength value λ
i', by λ
i' with the output wavelength λ of current tunable laser source
icompare, calculate the offset Δ λ of its reflectance spectrum centre wavelength thus
i=λ
i-λ '
i, according to i-th fiber-optic grating sensor emission spectrum original state central wavelength lambda that Step II obtains
iCcalculate i-th fiber-optic grating sensor emission spectrum Current central wavelength X '
iC=λ
iC+ Δ λ
i, and then demodulation obtains steel disc strain value.
V, work as i=2, skip to step I when confiscating and ceasing and desisting order, cease and desist order if receive, end of run; When i ≠ 2, i=i+1 is set, skips to step II.
IV, lasting Real-time demodulation steel disc strain value change
Continuous circulation performs step III, persistent loop mensuration is carried out to the data of 3 fiber-optic grating sensors and continues to carry out demodulation to the dependent variable of steel disc each point, the dependent variable of real-time follow-up each fiber-optic grating sensor present position steel disc, ceases and desist order until receive, and runs and stops.
The method of testing of this example has high speed real-time, and measurement sensistivity reaches 0.1 μ ε.
Above-described embodiment, be only the specific case further described object of the present invention, technical scheme and beneficial effect, the present invention is not defined in this.All make within scope of disclosure of the present invention any amendment, equivalent replacement, improvement etc., be all included within protection scope of the present invention.
Claims (5)
1., based on the method for real-time measurement of fiber Bragg grating sensor measuring system, what described method was used comprises tunable laser source, optical splitter, host computer, a light power meter and n fiber-optic grating sensor based on fiber Bragg grating sensor measuring system; Described fiber-optic grating sensor is fiber Bragg grating sensor; Host computer connection control tunable laser source and light power meter, tunable laser source connects a three-dB coupler, laser inputs from a point of optical port of three-dB coupler, arrive n the fiber Bragg grating sensor that it closes road port serial connection, and n is the integer of 1 ~ 120; Another point of optical port of three-dB coupler is connected to light power meter; And the synchronous triggering input port of light power meter connects the synchronous triggering delivery outlet of tunable laser source; Each fiber Bragg grating sensor has certain wavelength response range, and its reflectance spectrum is emergent power reflection at peak within the scope of this, the peak value P of power
maxcorresponding wavelength is called central wavelength lambda
c, the peak power of the most flash mould adjacent with main mould is main mould bottom power P
min, the power P of main mould crest both sides spectral line
minthe difference of the wavelength that place is corresponding is the bandwidth λ of this fiber Bragg grating sensor reflectance spectrum
bW; Each fiber Bragg grating sensor pair input light reflectance same with wherein cardiac wave appearance is 80 ~ 90%; It is characterized in that the job step of described method for real-time measurement is as follows:
I, experiment obtains the calibrating parameters of the linear relation between each fiber Bragg grating sensor centre wavelength and the measured physical quantity of demarcation
Reference instrument is used to demarcate the different value of measured physical quantity at least three, the centre wavelength of each fiber Bragg grating sensor corresponding under being simultaneously recorded in the measured physical quantity effect of each demarcation, use linear fit method to calculate the linear relation of measured physical quantity and fiber Bragg grating sensor centre wavelength, and record response parameter slope and the values of intercept of this linear equation;
II, the reference data table of n fiber Bragg grating sensor is generated
Before real-time testing in an initial condition, tunable laser source is used to carry out length scanning to n fiber Bragg grating sensor, the reflectance spectrum distribution situation of n cascaded fiber Bragg grating sensor is measured by light power meter, power unit is mw, and a crest represents a fiber Bragg grating sensor; I-th main mould peak power of fiber Bragg grating sensor reflectance spectrum is P
imax, bottom power is P
imin, i is the sequence number of n fiber Bragg grating sensor, i=0,1,2,3 ... n-1; Choose in any side of i-th fiber Bragg grating sensor reflectance spectrum main mould crest there is monotonicity one section of spectral line as the reference spectra of this fiber Bragg grating sensor; The upper extreme point corresponding wavelength of reference spectra is λ
iH, corresponding power is P
iH, its lower extreme point corresponding wavelength is λ
iL, corresponding power is P
iL, the reference spectra of each fiber Bragg grating sensor of described system is all got on the left of main mould crest or is all got right side, thus obtains taking i as the reference data table of sequence, comprises the reflectance spectrum parameter lambda of each fiber Bragg grating sensor under original state
iE, λ
i, P
iHand P
iL, wherein λ
ifor the middle wavelength of reference spectra, λ
iassignment is λ for the first time
i=0.5 (λ
iL+ λ
iH); λ
iE=0.5| λ
iH-λ
iL|; Record the centre wavelength value λ of reflectance spectrum under this fiber Bragg grating sensor original state simultaneously
iC;
III, the physical parameter of the corresponding test point of each fiber Bragg grating sensor is surveyed
According to the wavelength X of n fiber Bragg grating sensor in step II gained reference data table
iset the output wavelength of tunable laser source successively, use light power meter to measure the reflected optical power of each fiber Bragg grating sensor in real time, record each λ
ithe reflected optical power that corresponding fiber Bragg grating sensor is current, and calculate each fiber Bragg grating sensor center wavelength shift amount Δ λ
i; According to the output wavelength of tunable laser source and the fiber Bragg grating sensor sequence number of reflected optical power judgement correspondence, method of interpolation is utilized to calculate the skew of each fiber Bragg grating sensor reflectance spectrum by current reflective luminous power and reference data table; Measured physical quantity corresponding to each sensor place test point is obtained according to step I gained each fiber Bragg grating sensor centre wavelength and the linear relation demodulation of measured physical quantity;
IV, lasting Real-time demodulation measured physical quantity
Continuous circulation performs step III, measures and continues demodulation to measured physical quantity, the measured physical quantity that real-time follow-up is gradual, cease and desist order, run and stop until receiving the data persistence circulation of n fiber Bragg grating sensor.
2. the method for real-time measurement based on fiber Bragg grating sensor measuring system according to claim 1, is characterized in that the concrete steps of described step III are as follows:
I, i=0 is set;
II, the output wavelength arranging tunable laser source are λ
i;
III, measure i-th fiber Bragg grating sensor reflected optical power value P by light power meter
iand judge according to i-th fiber Bragg grating sensor corresponding power value of step II gained reference data table:
III-1, work as P
iL< P
i< P
iH, perform step IV;
III-2, work as P
i≤ P
iL, the output wavelength of adjustment tunable laser source,
When reference spectra is on the left of main mould crest, λ is set
i=λ
i+ λ
iE,
When reference spectra is on the right side of main mould crest, λ is set
i=λ
i-λ
iE,
Return afterwards and perform step II;
III-3, work as P
i>=P
iH, the output wavelength of adjustment tunable laser source,
When reference spectra is on the left of main mould crest, λ is set
i=λ
i-λ
iE,
When reference spectra is on the right side of main mould crest, λ is set
i=λ
i+ λ
iE,
Return afterwards and perform step II;
IV, computational reflect spectral shift amount, Real-time demodulation measured physical quantity; In step II gained reference data table, method of interpolation is utilized to draw this fiber Bragg grating sensor current power value P
icorresponding wavelength value λ '
i, by λ '
iwith the output wavelength λ of current tunable laser source
icompare, calculate the offset Δ λ of its reflectance spectrum centre wavelength thus
i=λ
i-λ '
i, according to i-th fiber Bragg grating sensor emission spectrum original state central wavelength lambda that Step II obtains
iCthe emission spectrum centre wavelength calculating current i-th fiber Bragg grating sensor is: λ '
iC=λ
iC+ Δ λ
i, and then demodulation obtains the data of the physical parameter to be measured of temperature or pressure or stress;
V, work as i=n-1, do not receive when ceasing and desisting order and skip to step I, cease and desist order if receive, end of run; As i ≠ n-1, i=i+1 is set, skips to step II.
3. the method for real-time measurement based on fiber Bragg grating sensor measuring system according to claim 1, is characterized in that:
When the making material of the multiple fiber Bragg grating sensors used in measuring system, technique are all identical with packaged type, the described step I response parameter of demarcating one of them fiber Bragg grating sensor is as the common response parameter of each fiber Bragg grating sensor used in measuring system.
4. the method for real-time measurement based on fiber Bragg grating sensor measuring system according to claim 1, is characterized in that:
The performance number P of reference spectra upper extreme point in described step II
iHbe main mould peak power P
imax90 ~ 95%, the value P of the power of the lower extreme point of reference spectra
iLbe main mould bottom power P
imin105 ~ 110%.
5. the method for real-time measurement based on fiber Bragg grating sensor measuring system according to claim 1, is characterized in that:
As the bandwidth λ of the reflectance spectrum of n fiber Bragg grating sensor of measuring system
bWequal, the dynamic range of its measure physical quantities is also equal simultaneously, and namely reflectance spectrum offset Δ λ is equal, and on the basis ensureing each sensor reflectance spectrum waveform integrality, the quantity n of fiber Bragg grating sensor meets:
n<(λ
ALL-λ
BW)/Δλ
Wherein, λ
aLLfor the scanning wavelength total bandwidth of described system tunable laser source used.
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| CN117109465B (en) * | 2023-08-31 | 2024-04-12 | 交通运输部天津水运工程科学研究所 | Decoupling calibration method for multi-physical-field strain sensing signals |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| CN201322624Y (en) * | 2008-11-27 | 2009-10-07 | 世纪晶源科技有限公司 | Fiber grating sensing device and circuit thereof |
| CN101650509A (en) * | 2009-09-15 | 2010-02-17 | 南京航空航天大学 | Bragg grating high-speed demodulating system based on cascade-connection long period fiber grating |
| CN102288289A (en) * | 2011-07-20 | 2011-12-21 | 厦门大学 | Method for determining peak wavelength of fiber grating |
| CN102374873A (en) * | 2011-09-19 | 2012-03-14 | 武汉邮电科学研究院 | Sensing system based on optical OFDM (Orthogonal Frequency Division Multiplexing) and FBG (Fiber Bragg Grating) monitoring method thereof |
| CN102506916A (en) * | 2011-11-22 | 2012-06-20 | 武汉邮电科学研究院 | Distributed sensor network using weak reflection fiber Bragg grating (FBG) and precise positioning method of each FBG |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6876786B2 (en) * | 2002-10-02 | 2005-04-05 | Cicese-Centro De Investigation | Fiber-optic sensing system for distributed detection and localization of alarm conditions |
| US20080106745A1 (en) * | 2006-08-31 | 2008-05-08 | Haber Todd C | Method and apparatus for high frequency optical sensor interrogation |
-
2012
- 2012-09-26 CN CN201210363013.6A patent/CN103674079B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| CN201322624Y (en) * | 2008-11-27 | 2009-10-07 | 世纪晶源科技有限公司 | Fiber grating sensing device and circuit thereof |
| CN101650509A (en) * | 2009-09-15 | 2010-02-17 | 南京航空航天大学 | Bragg grating high-speed demodulating system based on cascade-connection long period fiber grating |
| CN102288289A (en) * | 2011-07-20 | 2011-12-21 | 厦门大学 | Method for determining peak wavelength of fiber grating |
| CN102374873A (en) * | 2011-09-19 | 2012-03-14 | 武汉邮电科学研究院 | Sensing system based on optical OFDM (Orthogonal Frequency Division Multiplexing) and FBG (Fiber Bragg Grating) monitoring method thereof |
| CN102506916A (en) * | 2011-11-22 | 2012-06-20 | 武汉邮电科学研究院 | Distributed sensor network using weak reflection fiber Bragg grating (FBG) and precise positioning method of each FBG |
Non-Patent Citations (3)
| Title |
|---|
| 一种新型光纤光栅复用传感解调技术的研究;李志全等;《 光电子·激光 》;20040531;第15卷(第5期);第569-571页 * |
| 光纤布拉格光栅传感器阵列实时解调方案的研究;陈亮等;《舰船电子工程》;20081231;第28卷(第12期);第185-188页 * |
| 光纤布拉格光栅波长解调系统的研制;孟宪玮等;《吉林大学学报(地球科学版)》;20090331;第39卷(第2期);第342-346页 * |
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