CN102997945B - The multipoint disturbance positioning method of optical fiber distributed perturbation sensor - Google Patents
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Abstract
The invention discloses a kind of multipoint disturbance positioning method of optical fiber distributed perturbation sensor, described optical fiber distributed perturbation sensor is based on two Mach-Zehnder interferometer type optical fiber distributed perturbation sensor, said method comprising the steps of: S1: two interferometers respectively by two Mach-Zehnder interferometer obtain the first output signal and the second output signal; S2: carry out pre-service to described first output signal and the second output signal respectively, obtains the phase information in described first output signal and the second output signal; S3: time domain cross correlation process will be carried out through described pretreated described first and second output signals; S4: frequency domain spectra analyzing and processing is carried out to the result after described time domain cross correlation process; Extract the positional information of multipoint disturbance signal.The method of the application of the invention, makes it possible to adopt the location that structure is simple, hardware cost is low optical fiber distributed perturbation sensor realizes multipoint disturbance.
Description
Technical field
The present invention relates to optical fiber disturbance signal monitoring technical field, particularly relate to a kind of multipoint disturbance positioning method of optical fiber distributed perturbation sensor.
Background technology
Optical fiber distributed perturbation sensor can be monitored the disturbance (time varying signal) at any point place on sensor fibre, obtains the time domain waveform of disturbing signal, judges, provide warning message according to disturbance event character; Provide the spatial positional information that disturbance event occurs simultaneously.
According to different principle of work, optical fibre distribution type sensor can be divided into interferometer type, grating type optical fiber, optical time domain reflectometer type, the sensing technologies such as optical frequency domain reflectometer type and intensity modulation type.Wherein, realize principle simply because interferometer type distributed sensor has, highly sensitive, fast response time, hardware cost is low, is suitable for the good characteristics such as long-distance sensing, has become the main technical schemes of optical fiber distributed perturbation sensor.
At present, the theoretical scheme of interferometer type distributed optical fiber disturbance sensor mainly comprises single Sagnac type, span He-Ze De type, two Sagnac type, Sagnac+Michaelson and Sagnac+Mach-Ze De type, dual wavelength Sagnac type and double modulation frequency Sagnac type interferometer etc.Wherein, simple based on span He-Ze De type optical fibre distribution type sensor light channel structure, hardware cost is low, there is not the restriction of signal spectrum scope, can be realized the location of single-point disturbance by associated time delays algorithm.But in prior art when multiposition (multiple spot) disturbance simultaneously, the accurate location of disturbance location cannot be provided, reduce the Practical Performance of sensor.And except dual wavelength Sagnac type interferometer, the problem of disturbances location while that other interferometer type optical fiber distributed perturbation sensor being also difficult to realize multiple spot in prior art.
Based on the optical fiber distributed perturbation sensor of dual wavelength Sagnac type interferometer light path principle figure as shown in Figure 1.A broadband low-coherence light source is used wavelength-division multiplex technique and is divided into two band of light by wavelength.Light is propagated in two different Sagnac interferometers with different wavelength.The bidirectional optical path that first interferometer is made up of light source A, light path B, fiber delay time coil light path C, sensor fibre light path E, Piezoelectric Phase modulator light path F, light path H and detector I is formed; The bidirectional optical path that second Sagnac interferometer is made up of light source A, light path B, Piezoelectric Phase modulator light path D, sensor fibre light path E, fiber delay time coil light path G, light path H and detector I is formed.With a sinusoidal strain signal, (frequency is respectively f to each Sagnac interferometer
1, f
2) produce a phase bias, and f
1, f
2be different, should meet | f
1-f
2| be greater than the forcing frequency of measured signal, be namely greater than the fundamental frequency width of the output of sensor.Because phase bias provides the which amplitude modulation carrier signal of different frequency, so two interferometers can share a photo-detector to different interferometers.The sensitivity of interferometer can be improved to the corresponding high sloped region of sinusoidal phase by the working point of adjustment System.When sagnac loop there being disturbance, the odd harmonic signal of bias modulator starts to be detected.Photoelectric detector to signal to solve the output signal of two Sagnac interferometers through two active homodyne demodulation technical point.Fig. 2 is the theory diagram of the optical fiber distributed perturbation sensor demodulator circuit of dual wavelength Sagnac type interferometer, and wherein clock is clock, f
1, f
2, 2f
1, 2f
2be respectively the modulating frequency of two bias modulator frequencies and twice.Signal enters in two lock-in amplifiers, demodulates D (f respectively
1), D (f
2), D (2f
1), D (2f
2) result relevant with position that can process out simply.When system keeps the light phase modulation that causes of disturbance to be less than 0.1rad, just almost it doesn't matter with the rate of change of disturbance and amplitude for Output rusults.
The shortcoming of the above-mentioned optical fiber distributed perturbation sensor based on dual wavelength sagnek interferometer is:
1) prerequisite of disturbing signal demodulation and location is the effect (phase differential that namely disturbing signal causes is less than 0.1rad) that supposing the system is subject to small-signal; 2) relative phase shift that disturbance produces is the function of position on Sagnac loop, wherein sensor in the sensitivity of ring center close to zero; 3) owing to have employed the devices such as wavelength division multiplexer (WDM), the hardware cost of system and the complicacy of structure is added; 4) due to the imperfect type of wavelength division multiplexer, make to there is a certain amount of smooth serial interference, cause the error of system Output rusults, thus the mistake that improve system is warned rate and reduced the positioning precision of system.
These defects have above had a strong impact on the reliability of sensor in actual monitoring application, limit the actual enforcement of the program.
Summary of the invention
(1) technical matters that will solve
The technical problem to be solved in the present invention is: the multipoint disturbance positioning method providing a kind of optical fiber distributed perturbation sensor, the optical fiber distributed perturbation sensor that its structure based is simple, hardware cost is low achieves the location of multipoint disturbance, and there is not the intrinsic defect of dual wavelength Sagnac type interferometer.
(2) technical scheme
For solving the problem, the invention provides a kind of multipoint disturbance positioning method of optical fiber distributed perturbation sensor, described optical fiber distributed perturbation sensor is based on two Mach-Zehnder interferometer type optical fiber distributed perturbation sensor, said method comprising the steps of:
S1: two interferometers respectively by two Mach-Zehnder interferometer obtain the first output signal and the second output signal;
S2: carry out pre-service to described first output signal and the second output signal respectively, obtains the phase information in described first output signal and the second output signal;
S3: time domain cross correlation process will be carried out through described pretreated described first and second output signals;
S4: frequency domain spectra analyzing and processing is carried out to the result after described time domain cross correlation process; Extract the positional information of multipoint disturbance signal.
Preferably, the pre-service described in step S2 comprises:
S21: carry out every straight process to described first output signal and the second output signal respectively, filtering DC terms and low-frequency disturbance item;
S22: ask for the light intensity through described first and second output signals after straight process and visibility information respectively, to eliminate the change of the first and second output signal visibilitys and to obtain light intensity and the visibility information of described first and second output signals;
S23: the phase information extracting described first and second output signals after step S22 process respectively, and the undesired signal that filtering phase place is gradual.
Preferably, realizing every straight process by the direct electric capacity that adds on circuit or being realized by active or passive high-pass filtering mode in described step S21.
Preferably, the method asking for peak-to-peak value by segmentation in described step S22 is eliminated the change of described first and second output signal visibilitys and is obtained light intensity and the visibility information of described first and second output signals.
Preferably, eliminated the change of described first and second output signal visibilitys in described step S22 by anti-polarization decay technology and light power stabilising control technology, and obtain the intensity signal of described first and second output signals by asking for peak-to-peak value.
Preferably, described step S23 obtains the phase information of described first and second output signals by phase extraction method or PGC modulator approach.
Preferably, described step S23 carrys out the gradual undesired signal of filtering phase place by high-pass filtering.
Preferably, the pre-service described in described step S2 is also included between step S21 and S22 to be increased described first and second steps that output signal is amplified and filtering is nursed one's health, for restraint speckle and interference.
(3) beneficial effect
1) present invention preserves the light channel structure that current most advantage is also most widely used pair of Mach-Zehnder interferometer, there is light channel structure simple, the advantages such as hardware cost is low; 2) change of interference signal visibility of the present invention by eliminating the factor such as the optical power fluctuation that may be subject in positioning calculation process and signal polarization induction decline to the pre-service of disturbing signal and causing, thus also indirectly eliminate the problem of the possible sensor localization inefficacy that visibility change causes; 3) the present invention is by the phase drift signal to the pre-service of disturbing signal also filtering simultaneously, thus eliminates the gradual impact of phase place; 4) the present invention is correlated with and frequency domain spectra analysis by carrying out time domain to pretreated signal, has extracted positional information separately when different disturbance occurs simultaneously.The means realizing multipoint disturbance location only act on signal processing module, can pass through software simulating, not change light channel structure, thus do not introduce extra path error and device cost.
Accompanying drawing explanation
Fig. 1 is the light path principle figure based on the optical fiber distributed perturbation sensor of dual wavelength Sagnac type interferometer in prior art;
Fig. 2 is that prior art is based on dual wavelength Sagnac type optical fiber distributed perturbation sensor demodulator circuit schematic diagram;
Fig. 3 is the light path principle figure that the present invention is based on two Mach-Zehnder interferometer type optical fiber distributed perturbation sensor;
Fig. 4 is the process flow diagram according to multipoint disturbance positioning method of the present invention;
Fig. 5 is the process flow diagram according to preprocessing process of the present invention.
Embodiment
Below in conjunction with drawings and Examples, that the present invention is described in detail is as follows.
Fig. 3 is the light path principle figure that the present invention is based on two Mach-Zehnder interferometer type optical fiber distributed perturbation sensor.As shown in Figure 3, the light wave that sends of laser instrument Laser is via the first coupling mechanism C
1light splitting: a road light wave is propagated, through the first optical fiber L along counter clockwise direction
ctransmission, through the 3rd coupling mechanism C
3pickup arm L is injected respectively after light splitting
awith reference arm L
b, and then at the second coupling mechanism C
2place interferes, by the first photoelectric detector PD
1receive, constitute first interferometer; Another road light wave is propagated clockwise, through the second coupling mechanism C
2pickup arm L is injected respectively after light splitting
awith reference arm L
b, and then at the 3rd coupling mechanism C
3place interferes, by the second optical fiber L
dtransmission, by the second photoelectric detector PD
2receive, constitute second interferometer.
Ignore arm length difference in the present embodiment, therefore establish pickup arm L
a, reference arm L
b, the first optical fiber L
cwith the second optical fiber L
dlength be L.
The present embodiment records a kind of multipoint disturbance positioning method based on above-mentioned pair of Mach-Zehnder interferometer type optical fiber distributed perturbation sensor.Fig. 4 is the process flow diagram of multipoint disturbance positioning method of the present invention, as shown in Figure 4, said method comprising the steps of:
S1: by the first photoelectric detector PD of two Mach-Zehnder interferometers first interferometer
1obtain the first output signal; Simultaneously by the second photoelectric detector PD of described pair of Mach-Zehnder interferometer second interferometer
2obtain the second output signal;
For 2 disturbances simultaneously.As 2 disturbance f
1(t) and f
2when () occurs simultaneously t, the length of optical fiber and propagation constant will change, thus cause the phase place in interferometer to change.If the phase place change that two disturbances cause is respectively
with
wherein
In formula, L is the brachium of interferometer, and β is propagation constant, Δ L
1with Δ L
2the fiber lengths change of two-arm, Δ β
1with Δ β
2it is the propagation constant change of two-arm.Theoretical according to Fibre Optical Sensor, the change exporting phase information is proportional to disturbing signal, has
In formula, B is the scale factor corresponding with disturbance phase place.
Therefore described first detector PD
1with the second detector PD
2to receive and the two paths of signals exported is respectively
In formula, τ
1and τ
2that light is from two disturbance points to the first detector PD respectively
1travel-time, τ
3and τ
4that light is from two disturbance points to the second detector PD respectively
2travel-time.K
1and K
2the visibility of interferometer,
the first difference of interferometer, I
0depend on the luminous power that laser instrument exports.For simplifying the analysis, the length difference of sensor fibre and conduction optical fiber is ignored, L
1and L
2two perturbation distance the 3rd coupling mechanism C respectively
3distance, the travel-time is expressed as:
S2: carry out pre-service to described first output signal and the second output signal respectively, obtains the phase information in described first output signal and the second output signal;
Pre-service described in step S2 comprises:
S21: carry out every straight process to described first output signal and the second output signal respectively, filtering DC terms and low-frequency disturbance item; Realizing every straight process by the direct electric capacity that adds on circuit or being realized by active or passive high-pass filtering mode in described step S21;
S22: ask for the light intensity through described first and second output signals after straight process and visibility information respectively, to eliminate the change of the first and second output signal visibilitys and to obtain light intensity and the visibility information of described first and second output signals;
Interference signal generally has cosine function form, visibility information can be asked for by the mode asking for signal peak peak value, but due to the impact of the factors such as polarization decay, the visibility of different time sections can change, therefore the method asking for peak-to-peak value in the present embodiment by carrying out segmentation to the time is eliminated the change of described first and second output signal visibilitys and obtains the intensity signal of described first and second output signals, object is the impact reducing or eliminate visibility, realize better asking for light intensity and visibility information, reduce error; The first and second output signals after step S22 process are:
Except the method that peak-to-peak value is asked in above-mentioned segmentation, the present embodiment can also adopt anti-polarization decay technology and light power stabilising control technology to eliminate the change of described first and second output signal visibilitys, and obtains light intensity and the visibility information of described first and second output signals by asking for peak-to-peak value;
S23: the phase information extracting described first and second output signals after step S22 process respectively, and the undesired signal that filtering phase place is gradual.
I is obtained by carrying out cosine function phase extraction algorithms to formula (11) and (12) in the present embodiment
1' (t) and I
2the phase information of ' (t), obtains:
Wherein,
the gradual undesired signal of phase place, in the present embodiment by high-pass filtering by its filtering, formula (13) and (14) are become:
In the present embodiment, the object of the phase information that cosine function phase extraction algorithms extracts in trigonometric function is for signal framing below provides basic preparation, and by other phase unwrapping algorithm or similar phase information extraction algorithm, as PGC modulation (comprising PGC internal modulation and PGC external modulation), the phase information in trigonometric function also can be extracted.
In other embodiments, can also increase described first and second steps that output signal is amplified and filtering is nursed one's health between step S21 and S22, for restraint speckle and interference.
S3: time domain cross correlation process will be carried out through described pretreated described first and second output signals;
Usually, two disturbing signal f are supposed
1(t) and f
2t () is respectively
A in formula
i, A '
j, ω
i, ω '
j,
with
represent the amplitude of two disturbances, angular frequency and initial phase respectively, N and M is the quantity of the frequency content component of two disturbances respectively.
According to formula (3) and (4), can obtain
In formula, B
iand B
j' represent that two disturbances cause the amplitude of phase differential respectively.
Wushu (19) and (20) substitute into formula (15) and (16) respectively, can obtain
Derive according to formula (21) and (22) and draw:
(23)
To I
3(t) and I
4t () does computing cross-correlation, can obtain
(24)
In formula (24), B
k", ω
k" and
represent the amplitude of same frequency composition component in two disturbances, angular frequency and initial phase respectively, P is the quantity of same frequency composition.In formula (24), same frequency composition component can be expressed as:
Wherein,
S4: carry out frequency domain spectra analyzing and processing to the result after described time domain cross correlation process, extracts the positional information of multipoint disturbance signal; Namely be that variable carries out phase spectral analysis to formula (24) with τ, the position L of two disturbances can be extracted
1and L
2.The location algorithm of 2 disturbances is generalized to the disturbance of more than 3 and 3, the detection and positioning of the optical fiber distributed perturbation sensor multiple spot disturbance simultaneously based on two Mach-Zehnder interferometer can be realized.
Above embodiment is only for illustration of the present invention; and be not limitation of the present invention; the those of ordinary skill of relevant technical field; without departing from the spirit and scope of the present invention; can also make a variety of changes and modification; therefore all equivalent technical schemes also belong to category of the present invention, and scope of patent protection of the present invention should be defined by the claims.
Claims (5)
1. a multipoint disturbance positioning method for optical fiber distributed perturbation sensor, is characterized in that, described optical fiber distributed perturbation sensor is based on two Mach-Zehnder interferometer type optical fiber distributed perturbation sensor, said method comprising the steps of:
S1: two interferometers respectively by two Mach-Zehnder interferometer obtain the first output signal and the second output signal;
S2: carry out pre-service to described first output signal and the second output signal respectively, obtains the phase information in described first output signal and the second output signal;
S3: time domain cross correlation process will be carried out through described pretreated described first and second output signals;
S4: frequency domain spectra analyzing and processing is carried out to the result after described time domain cross correlation process; Extract the positional information of multipoint disturbance signal;
Pre-service described in step S2 comprises:
S21: carry out every straight process to described first output signal and the second output signal respectively, filtering DC terms and low-frequency disturbance item;
S22: ask for the light intensity through described first and second output signals after straight process and visibility information respectively, asks for the method for peak-to-peak value to utilize segmentation or eliminates the change of the first and second output signal visibilitys by anti-polarization decay technology and light power stabilising control technology and obtain light intensity and the visibility information of described first and second output signals;
S23: the phase information extracting described first and second output signals after step S22 process respectively, and the undesired signal that filtering phase place is gradual.
2. the multipoint disturbance positioning method of optical fiber distributed perturbation sensor as claimed in claim 1, is characterized in that, being realized every straight process by the direct electric capacity that adds on circuit or being realized by active or passive high-pass filtering mode in described step S21.
3. the multipoint disturbance positioning method of optical fiber distributed perturbation sensor as claimed in claim 1, is characterized in that, described step S23 obtains the phase information of described first and second output signals by phase extraction method or PGC modulator approach.
4. the multipoint disturbance positioning method of optical fiber distributed perturbation sensor as claimed in claim 1, it is characterized in that, described step S23 carrys out the gradual undesired signal of filtering phase place by high-pass filtering.
5. the multipoint disturbance positioning method of optical fiber distributed perturbation sensor as claimed in claim 1, it is characterized in that, pre-service described in described step S2 is also included between step S21 and S22 to be increased described first and second steps that output signal is amplified and filtering is nursed one's health, for restraint speckle and interference.
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CN113639847A (en) * | 2021-08-06 | 2021-11-12 | 天津大学 | Pulse modulation and demodulation module and distributed optical fiber vibration sensing positioning method |
CN114018392B (en) * | 2021-11-04 | 2024-03-01 | 全球能源互联网研究院有限公司 | Polarization fading inhibition method and device |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0160450A2 (en) * | 1984-04-25 | 1985-11-06 | The Board Of Trustees Of The Leland Stanford Junior University | Phase reading fiber optic interferometer |
CN101464166A (en) * | 2009-01-08 | 2009-06-24 | 北京航空航天大学 | Optical fiber distributed perturbation sensor and method for implementing perturbation positioning |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100561144C (en) * | 2006-06-15 | 2009-11-18 | 华中科技大学 | Distributed optical fiber vibration sensing method and device |
-
2011
- 2011-09-16 CN CN201110274681.7A patent/CN102997945B/en active Active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0160450A2 (en) * | 1984-04-25 | 1985-11-06 | The Board Of Trustees Of The Leland Stanford Junior University | Phase reading fiber optic interferometer |
CN101464166A (en) * | 2009-01-08 | 2009-06-24 | 北京航空航天大学 | Optical fiber distributed perturbation sensor and method for implementing perturbation positioning |
Non-Patent Citations (2)
Title |
---|
双马赫-曾德尔分布式光纤传感系统定位技术;陈伟民等;《光学学报》;20071231;第27卷(第12期);第2128-2132页及附图1 * |
长途油气管道破坏预警的干涉型分布式光纤传感系统定位技术研究;吴俊;《优秀硕士论文全文库工程科技Ⅰ辑B019-33》;20070531;正文第7-30页 * |
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Effective date of registration: 20211025 Address after: 421000 Hengshan Science City mangrove R & D Innovation Zone, group 12, Dongfeng Village, Yueping Town, Yanfeng District, Hengyang City, Hunan Province Patentee after: HUNAN SHUAIWEI CONTROL TECHNOLOGY Co.,Ltd. Address before: 100191 Institute of optoelectronic technology, Beijing University of Aeronautics and Astronautics, 37 Xueyuan Road, Haidian District, Beijing Patentee before: BEIHANG University |