CN110146116B - Positioning method for Sagnac optical fiber sensing under multipoint disturbance - Google Patents
Positioning method for Sagnac optical fiber sensing under multipoint disturbance Download PDFInfo
- Publication number
- CN110146116B CN110146116B CN201910529199.XA CN201910529199A CN110146116B CN 110146116 B CN110146116 B CN 110146116B CN 201910529199 A CN201910529199 A CN 201910529199A CN 110146116 B CN110146116 B CN 110146116B
- Authority
- CN
- China
- Prior art keywords
- disturbance
- optical fiber
- signal
- phase difference
- sagnac
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 11
- 239000013307 optical fiber Substances 0.000 title claims abstract description 10
- 238000004422 calculation algorithm Methods 0.000 claims abstract description 8
- 230000003595 spectral effect Effects 0.000 claims abstract description 7
- 238000012897 Levenberg–Marquardt algorithm Methods 0.000 claims description 4
- 238000013528 artificial neural network Methods 0.000 claims description 4
- 239000000835 fiber Substances 0.000 claims description 3
- 238000006243 chemical reaction Methods 0.000 claims description 2
- 238000001228 spectrum Methods 0.000 abstract description 6
- 238000012544 monitoring process Methods 0.000 description 4
- 238000004364 calculation method Methods 0.000 description 1
- 230000009545 invasion Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
The invention discloses a positioning method of Sagnac optical fiber sensing under multipoint disturbance, which is characterized in that a notch spectrum under an assumed disturbance condition is adopted to fit a measured notch spectrum through a certain algorithm until the error of the notch spectrum and the notch spectrum is smaller than an expected fitting error. The invention has the advantages that: the position of the multi-point disturbance can be fitted from the power spectral density of the measured phase difference signal, so that the positioning during the multi-point disturbance is realized.
Description
Technical Field
The invention relates to the technical field of positioning of Sagnac optical fiber sensing, in particular to a positioning method of a Sagnac optical fiber sensing system under multipoint disturbance.
Background
The Sagnac optical fiber sensing system has wide application prospect, can be used for monitoring pipeline leakage and invasion, monitoring perimeter security protection, monitoring health of subway tunnels and monitoring ocean acoustic signals, and has important significance for guaranteeing life and property safety of people.
In Sagnac fiber optic sensing systems, the most common positioning method is a notch frequency based scheme. In order to realize positioning when a plurality of position points simultaneously generate disturbance, methods such as double fourier transform are proposed. However, in these methods, since the influence of the disturbances at different positions on the notch frequency is considered to be isolated, the positions of the disturbance points are directly derived by separating the notch frequencies at different periods and then measuring the respective notch frequencies or periods of the notch frequencies.
When two same disturbance points appear at different positions, the relation between the notch point notch frequency and the distance difference and the distance sum of the two disturbance positions can be deduced from a trigonometric function formula.
However, if the amplitudes of the two disturbance signals are different, or if more than two disturbances occur, the relationship between the notch frequency and the disturbance position cannot be theoretically deduced. The patent aims to solve the problem of positioning of disturbance signals under the conditions.
Disclosure of Invention
The invention aims to solve the problems that: the positioning method of the Sagnac optical fiber sensing system under multi-point disturbance is provided to solve the problem of positioning failure when disturbance occurs to a plurality of position points simultaneously.
The technical scheme provided by the invention for solving the problems is as follows: the notch spectrum of the assumed perturbation situation is fitted by a certain algorithm to the measured notch spectrum until the error between the two is smaller than the expected fitting error, and the specific steps are as follows,
(1) firstly, two paths of signals acquired by a double-channel data acquisition card are subjected to a passive homodyne demodulation method to obtain a phase difference signal
(2) And demodulating the obtained phase difference signal
The power spectral density is obtained by conversion
(3) The theoretical phase difference signal is:
wherein A is the action coefficient of the disturbance signal and the optical fiber, N is the number of disturbance points, M is the total frequency of the disturbance signal, and LsjIs the location of the disturbance, ωsiIs the frequency of the disturbing signal, BijIs LsjPosition disturbance signal at frequency omegasiAmplitude of (d), τtIs the time taken to make a loop around the Sagnac loop, LdIs the length of the delay fiber, n is the refractive index, c is the speed of light;
(4) setting Lsj，BijA value of (d);
(5) calculating power spectral density S of theta (t)θ(f)；
(6) To find
If the expected fitting error is min, the calculation can be carried out by a LevenbergMarquardt algorithm or a neural network algorithm
If it is
Then L can be modified by the Levenberg Marquardt algorithm or the neural network algorithmsj，BijReturning to the step (4); if it is
At this time Lsj，BijThe value of (b) is considered to be the actual value. At this point, positioning is achieved.
Compared with the prior art, the invention has the advantages that: the position of the multi-point disturbance can be fitted from the power spectral density of the measured phase difference signal, so that the positioning during the multi-point disturbance is realized.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.
FIG. 1 is a flow chart of an algorithm employed by the embodiment.
Detailed Description
Examples
a) Set Lsj，BijMin is the initial value of three;
b) power spectral density S of theta (t) is obtainedθ(f)；
c) If it is
Then L issj，BijThe value of (b) is considered as the fitting value if
Then L is modified according to the algorithm employedsj，BijThe value of (c).
Claims (1)
1. A Sagnac optical fiber sensing positioning method under multipoint disturbance is characterized by comprising the following steps:
(1) firstly, two paths of signals acquired by a double-channel data acquisition card are subjected to a passive homodyne demodulation method to obtain a phase difference signal
(2) And demodulating the obtained phase difference signal
The power spectral density is obtained by conversion
(3) The theoretical phase difference signal is:
wherein A is the action coefficient of the disturbance signal and the optical fiber, N is the number of disturbance points, M is the total frequency of the disturbance signal, and LsjIs the location of the disturbance, ωsiIs the frequency of the disturbing signal, BijIs LsjPosition disturbance signal at frequency omegasiAmplitude of (d), τtIs the time taken to make a loop around the Sagnac loop, LdIs the length of the delay fiber, n is the refractive index, c is the speed of light;
(4) setting Lsj，BijA value of (d);
(5) calculating power spectral density S of theta (t)θ(f)；
(6) To find
Let the expected fitting error be min, it can pass LevenbergMarquardt algorithm or neural network algorithm, solving
If it is
Then L can be modified by the Levenberg Marquardt algorithm or the neural network algorithmsj，BijReturning to the step (4); if it is
At this time Lsj，BijThe value of (b) is considered to be the actual value, and at this time, the positioning is achieved.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910529199.XA CN110146116B (en) | 2019-06-19 | 2019-06-19 | Positioning method for Sagnac optical fiber sensing under multipoint disturbance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910529199.XA CN110146116B (en) | 2019-06-19 | 2019-06-19 | Positioning method for Sagnac optical fiber sensing under multipoint disturbance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110146116A CN110146116A (en) | 2019-08-20 |
| CN110146116B true CN110146116B (en) | 2021-04-27 |
Family
ID=67595793
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910529199.XA Active CN110146116B (en) | 2019-06-19 | 2019-06-19 | Positioning method for Sagnac optical fiber sensing under multipoint disturbance |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110146116B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111238552B (en) * | 2020-02-27 | 2021-06-22 | 南昌航空大学 | Distributed optical fiber sensing system disturbance positioning method based on deep learning |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB0407386D0 (en) * | 2004-03-31 | 2004-05-05 | British Telecomm | Monitoring a communications link |
| CN100437050C (en) * | 2006-11-15 | 2008-11-26 | 北京航空航天大学 | Distribution type fiber-optic vibration sensor |
| CN101487723B (en) * | 2009-03-02 | 2011-01-05 | 北京航空航天大学 | Optical fiber distributed perturbation sensor based on Sagnac interferometer |
| CN102401667B (en) * | 2011-09-29 | 2016-03-30 | 北京航空航天大学 | There is optical fiber distributed perturbation method for sensing and the system of disturbance character recognition function |
| CN102538845B (en) * | 2011-12-08 | 2014-11-26 | 北京航空航天大学 | Multi-point disturbance location method |
| US20130265583A1 (en) * | 2012-04-06 | 2013-10-10 | Teledyne Scientific & Imaging, Llc | Fiber optic position sensing system |
| CN104008621B (en) * | 2014-06-03 | 2016-04-13 | 天津求实飞博科技有限公司 | Defence area type optical fiber disturbance perimeter security system and invasion disturbance method for rapidly judging |
| CN104215271B (en) * | 2014-07-30 | 2017-02-15 | 复旦大学 | Positioning method for disturbance position in distributed optical fiber disturbance monitoring system |
| CN104240455B (en) * | 2014-08-07 | 2016-08-17 | 北京航天控制仪器研究所 | A kind of disturbance event recognition methods in distribution type fiber-optic pipeline safety early warning system |
| CN105488935B (en) * | 2015-12-25 | 2018-01-16 | 天津大学 | A kind of distributed optical fiber disturbance positioning system and its localization method based on asymmetric double Mach Zehnder interference |
| CN106248119B (en) * | 2016-07-14 | 2018-11-13 | 南京大学 | A kind of distribution ultrahigh speed disturbance quantitative detecting method and device |
| CN206804030U (en) * | 2017-02-06 | 2017-12-26 | 安徽师范大学 | A kind of distributed vibration positioning sensor system based on linear pattern Sagnac interference and Φ OTDR |
| CN107505041B (en) * | 2017-07-31 | 2021-09-07 | 南京法艾博光电科技有限公司 | Phase demodulation device and method based on phase sensitive optical time domain reflectometer |
| CN108225541A (en) * | 2017-12-29 | 2018-06-29 | 鞍山睿科光电技术有限公司 | The distributed fiberoptic sensor and foreign body intrusion signal for identifying foreign body intrusion perceive processing method |
| CN108759882B (en) * | 2018-05-03 | 2021-01-12 | 上海大学 | Semiconductor laser mutual injection type distributed optical fiber sensing system and positioning method |
-
2019
- 2019-06-19 CN CN201910529199.XA patent/CN110146116B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110146116A (en) | 2019-08-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Liu et al. | A high-efficiency multiple events discrimination method in optical fiber perimeter security system | |
| CN101840615B (en) | Self-adaptive warning system for intelligently addressing circumferential intrusions of fiber Bragging grating | |
| CN103090961B (en) | Disturbance source positioning method of distributed type optical fiber sensing system | |
| CN107270952B (en) | Long-distance optical fiber distributed disturbance sensing signal processing method based on optical frequency domain reflection | |
| CN102624456B (en) | Optical fiber interference type sensing signal demodulating system and method | |
| CN103047540B (en) | Based on the optical path system for monitoring leakage of natural gas of Fibre Optical Sensor | |
| CN110146116B (en) | Positioning method for Sagnac optical fiber sensing under multipoint disturbance | |
| CN103983261B (en) | A fiber optic gyroscope based on vector space analysis and a signal processing method thereof | |
| CN104111082A (en) | High-precision FBG sensing signal peak searching method | |
| CN110057387B (en) | Positioning method of linear Sagnac distributed optical fiber sensing system | |
| CN101922946A (en) | All-fiber positioning monitoring system | |
| CN103196465A (en) | Method for separating noise of sensing signal and extracting signal of phase-sensitive optical time domain reflectometer | |
| CN103944174A (en) | Low frequency oscillation online identification method based on cross-correlation function denoising algorithm | |
| Ma et al. | A continuous wavelet transform based time delay estimation method for long range fiber interferometric vibration sensor | |
| CN105277272A (en) | Distributed optical fiber vibration sensing multi-point disturbance localization algorithm | |
| CN105509979A (en) | Fiber optic negative pressure wave-based oil and gas pipeline leakage monitoring positioning system and method | |
| CN103743435A (en) | Multi-sensor data fusion method | |
| CN103995969B (en) | Configurable optical fiber invasion event occurring end point detecting method and detector | |
| CN104197206A (en) | Distributed fiber-optic sensing based oil-gas pipeline safety monitoring system and method | |
| CN109188017A (en) | A kind of wind direction and wind velocity detection device and detection method based on array of ultrasonic sensors | |
| US20200141769A1 (en) | Method for processing long-distance optical fiber distributed disturbance sensing signal based on optical frequency domain reflectometry | |
| CN104376306A (en) | Optical fiber sensing system invasion identification and classification method and classifier based on filter bank | |
| CN111238552B (en) | Distributed optical fiber sensing system disturbance positioning method based on deep learning | |
| CN103499834A (en) | Method and device for recovering low-frequency signals of seismic data of analog detector | |
| CN103148872B (en) | A kind of optical fiber distributed perturbation sensor localization method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |