CN114777899B - Monitoring system and method based on distributed sensor - Google Patents
Monitoring system and method based on distributed sensor Download PDFInfo
- Publication number
- CN114777899B CN114777899B CN202210318122.XA CN202210318122A CN114777899B CN 114777899 B CN114777899 B CN 114777899B CN 202210318122 A CN202210318122 A CN 202210318122A CN 114777899 B CN114777899 B CN 114777899B
- Authority
- CN
- China
- Prior art keywords
- optical fiber
- polarization
- coherent
- coherent light
- unit
- 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
- 238000012544 monitoring process Methods 0.000 title claims abstract description 27
- 238000000034 method Methods 0.000 title claims abstract description 20
- 239000013307 optical fiber Substances 0.000 claims abstract description 122
- 230000010287 polarization Effects 0.000 claims abstract description 104
- 230000001427 coherent effect Effects 0.000 claims abstract description 77
- 230000003287 optical effect Effects 0.000 claims description 32
- 238000010219 correlation analysis Methods 0.000 claims description 18
- 238000001228 spectrum Methods 0.000 claims description 16
- 239000000835 fiber Substances 0.000 claims description 9
- 230000004807 localization Effects 0.000 claims 1
- 238000001514 detection method Methods 0.000 abstract description 4
- 238000005562 fading Methods 0.000 abstract description 4
- 230000035945 sensitivity Effects 0.000 abstract description 2
- 230000000694 effects Effects 0.000 description 8
- 230000001133 acceleration Effects 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 238000009412 basement excavation Methods 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000012806 monitoring device Methods 0.000 description 2
- 239000011435 rock Substances 0.000 description 2
- 230000008054 signal transmission Effects 0.000 description 2
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G01H9/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
- G01H9/004—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means using fibre optic sensors
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The invention discloses a monitoring system and a monitoring method based on a distributed sensor, wherein the monitoring system comprises: a sensing unit; the first coherent light generating unit comprises a first pulse laser, a first polarization beam splitter, a first optical fiber polarization controller, a first polarization optical fiber coupler and a first compensation optical fiber; the first coherent phase analysis unit is used for carrying out phase analysis on the first coherent light generated by the first coherent light generation unit; the second coherent light generating unit comprises a second pulse laser, a second polarization beam splitter, a second optical fiber polarization controller, a second polarization optical fiber coupler and a second compensation optical fiber; and a second coherent phase analysis unit for performing phase analysis on the second coherent light generated by the second coherent light generation unit. The system provided by the invention is simple, low in cost, high in signal-to-noise ratio and sensitivity, long in distributed sensing detection distance, low in requirements on light source coherence, free of coherent fading influence, good in system stability and durability, high in reliability and capable of being monitored online for a long time.
Description
Technical Field
The invention relates to a super-long distance distributed vibration sensing technology and a device, which are used for distributed sensing of various vibrations, microseism, earthquake waves, sound waves, ultrasonic waves, dynamic strain or acceleration. The real-time on-line monitoring and positioning of vibration and acoustic signals such as structural damage, geological activity, engineering vibration, underwater sound monitoring, resource exploration, marine exploration, optical cable detection, intrusion disturbance and the like in a long-distance range can be realized.
Background
At present, the existing full-distributed optical fiber vibration and acoustic sensing system is basically based on an interference type or coherent type sensing technology, generally adopts a loop or converging light path design, mainly generates interference or coherence through light converging of two opposite propagation paths or two different propagation paths, and detects and analyzes the intensity and phase change of the interference or coherent signal so as to acquire external vibration or acoustic signals of the propagation paths. The existing system has the defects that in order to realize long-distance distributed interference sensing, a sensing light source is generally required to have an extremely narrow line width so as to improve the coherence and the sensing distance, the system cost is greatly increased, and the sensing distance of the light source is severely limited by the line width of the light source. In addition, the loop or double-path coherent sensing structure causes the increase of the signal transmission distance, can limit the system sensing distance, can bring coherent fading and seriously affects the distributed sensing effect. The technical performance of the distributed optical fiber vibration sensing system is still limited, so that the sensing distance cannot be greatly improved, the distributed effect is difficult to further improve, the system is complex, and the cost is difficult to reduce.
Disclosure of Invention
The invention aims to provide a monitoring system and a monitoring method based on a distributed sensor, which are used for distributed sensing of various types of vibration, microseism, earthquake waves, sound waves, ultrasonic waves, dynamic strain or acceleration. The system has the advantages of simplicity, low cost, high coherent signal power, high signal to noise ratio and high sensitivity, can realize sensing through self-coherence in transmission pulse, has low requirements on the coherence of the light source, avoids limitation of the coherence to the sensing distance, ensures long detection distance of distributed sensing, does not need loop or double-path convergence interference design, has no influence of coherent fading, has good stability and durability and high reliability, and can realize long-term on-line monitoring.
The technical scheme of the invention is as follows:
the invention first provides a monitoring system based on a distributed sensor, comprising:
the sensing unit is internally provided with an optical fiber sensor;
The first coherent light generating unit comprises a first pulse laser, a first polarization beam splitter, a first optical fiber polarization controller, a first polarization optical fiber coupler and a first compensation optical fiber; the pulse light signal generated by the first pulse laser enters the sensing unit and then enters the first polarization beam splitter; the first polarization beam splitter divides an incoming optical signal into two paths of linearly polarized light output with mutually perpendicular vibration directions, a first path of the linearly polarized light output enters the first optical fiber polarization controller to rotate in the vibration direction and is parallel to the vibration direction of a second path of the linearly polarized light output, and the second path of the linearly polarized light output enters the first compensation optical fiber to perform phase compensation and has the same phase as that of the first path of the linearly polarized light output; the first path of output rotated by the first optical fiber polarization controller and the second path of output compensated by the first compensation optical fiber enter a first polarization optical fiber coupler to be coupled to form first coherent light;
A first coherent phase analysis unit configured to perform phase analysis on the first coherent light generated by the first coherent light generation unit;
The second coherent light generating unit comprises a second pulse laser, a second polarization beam splitter, a second optical fiber polarization controller, a second polarization optical fiber coupler and a second compensation optical fiber; the pulse light signals generated by the second pulse laser enter the sensing unit and then enter the second polarization beam splitter; the second polarization beam splitter divides the incoming optical signal into two paths of linearly polarized light output with mutually perpendicular vibration directions, the first path enters the second optical fiber polarization controller to rotate in the vibration direction and be parallel to the vibration direction of the second path, and the second path enters the second compensation optical fiber to perform phase compensation and has the same phase as the first path; the first path of output through the second optical fiber polarization controller (rotating and the second path of output through the second compensation optical fiber are compensated by the second compensation optical fiber and enter a second polarization optical fiber coupler to be coupled to form second coherent light;
a second coherent phase analysis unit configured to perform phase analysis on the second coherent light generated by the second coherent light generation unit;
And a correlation analysis unit for performing correlation analysis on the analysis results of the first and second coherent phase analysis units.
The monitoring system further comprises: time delay judging and positioning and vibration characteristic analysis; the time delay judging and positioning is used for analyzing and comparing the correlation of the two groups of phase changes and the time delay so as to realize disturbance positioning; and analyzing and identifying signal characteristics such as phase change frequency spectrums of interference signals among different pulses by vibration characteristic analysis so as to determine the type and characteristics of external disturbance.
The front end of the sensing unit is connected with a first optical fiber coupler, and the rear end of the sensing unit is connected with a second optical fiber coupler; the output of the first pulse laser enters the sensing optical cable through the first optical fiber coupler and is output from the second optical fiber coupler; the output of the second pulse laser enters the sensing unit through the second optical fiber coupler and is output from the first optical fiber coupler.
The first coherent light generating unit further comprises a first photoelectric detector and a first data acquisition unit; the first photoelectric detector converts the first coherent light generated by the first polarization fiber coupler into an electric signal and then enters the first data acquisition unit.
The second coherent light generating unit further comprises a second photodetector and a second data acquisition unit; the second photoelectric detector converts the second coherent light generated by the second polarization fiber coupler into an electric signal and then enters the second data acquisition unit.
The sensing unit is a sensing optical cable.
The invention also provides a monitoring method based on the distributed sensor, which is characterized by comprising the following steps:
a first pulse laser is adopted, so that pulse laser passing through a sensing unit generates first coherent light under the action of a first polarization beam splitter, a first optical fiber polarization controller, a first polarization optical fiber coupler and a first compensation optical fiber;
A second pulse laser is adopted, so that pulse laser passing through the sensing unit generates second coherent light under the action of a second polarization beam splitter, a second optical fiber polarization controller, a second polarization optical fiber coupler and a second compensation optical fiber;
Carrying out phase analysis on the first coherent light and the second coherent light;
And performing correlation analysis and time delay analysis on the two groups of coherent light subjected to phase analysis to realize disturbance positioning.
The method for carrying out correlation analysis and time delay analysis on two groups of coherent light subjected to phase analysis so as to realize disturbance positioning comprises the following steps: the two photoelectric detectors are respectively analyzed to receive the cross correlation of the disturbance characteristics of the light signals transmitted by the two ends of the sensing optical fiber, whether the light signals are the same disturbance signal is analyzed, identified and confirmed, and the disturbance occurrence position is confirmed by analyzing the time delay of the two signals on the basis.
Further comprises: and analyzing and identifying the phase change spectrum signal characteristics of the interference signals among different pulses so as to identify the external disturbance source.
The method for analyzing and identifying the phase change spectrum signal characteristics of the interference signals among different pulses comprises the following steps:
Demodulating a series of pulse coherent optical signal phases in sequence;
The change rule and trend of the phase signal are obtained by difference through signals between adjacent pulses and equidistant pulses respectively, and the frequency spectrum characteristics of the phase signal change are analyzed;
And matching the spectrum characteristics obtained through analysis with the set disturbance type to obtain the type of the disturbance source. Sources of disturbance such as excavation, vehicle travel, earthquakes, structural cracking, landslides, falling rocks, and the like.
The monitoring device and the monitoring method are used for distributed sensing of various vibration, microseism, earthquake waves, sound waves, ultrasonic waves, dynamic strain or acceleration, any pulse light signal can be decomposed into two vertical vibration components, the two vertical vibration components are converted into components with parallel vibration directions through the optical rotation crystal, so that the two components can meet interference conditions and converge to generate self-coherence, the requirement of ultra-long distance optical fiber sensing on high coherence of a light source is reduced, the optical fiber birefringence effect is combined on the basis, the optical fiber micro-deformation is caused by utilizing external vibration or sound to enable the phase change of the two vibration components to be different, the external vibration and acoustic signal sensing is realized by detecting the phase difference change of the two self-coherent signals of the resolved light signal, the influence caused by coherent or polarization fading is effectively avoided, and finally the high signal-to-noise ratio long distance distributed acoustic sensing is realized.
Drawings
Fig. 1 is a schematic view of a specific structure of the present invention.
Detailed Description
The present invention will be described in detail below with reference to the attached drawings, but should not be construed as limiting the scope of the invention.
The invention is described in detail below with reference to fig. 1:
The present embodiment provides a monitoring device, which includes a first pulse laser 1, a first optical fiber coupler 2, a sensing optical cable 3, a second optical fiber coupler 4, a first polarization beam splitter 5, a first optical fiber polarization controller 6, a first polarization optical fiber coupler 7, a first compensation optical fiber 8, a first photodetector 9, a first data acquisition unit 10, a first coherent phase analysis unit 11, a second pulse laser 13, a second polarization beam splitter 14, a second optical fiber polarization controller 15, a second polarization optical fiber coupler 16, a second compensation optical fiber 17, a second photodetector 18, a second data acquisition unit 19, a second coherent phase analysis unit 20, and a correlation analysis unit 12.
The first pulse laser 1 emits laser pulses to enter the sensing optical cable 3 through the first optical fiber coupler 2, the light transmitted by the sensing optical cable 3 enters the first polarization beam splitter 5 through the second optical fiber coupler 4 and is divided into two paths, wherein the first path enters the first polarization optical fiber coupler 7 after passing through the first optical fiber polarization controller 6, and the other path enters the first polarization optical fiber coupler 7 after passing through the first compensation optical fiber 8. The output light of the first polarization fiber coupler 7 is converted into an electric signal by the first photoelectric detector 9, and then sequentially passes through the first data acquisition unit 10 and the first coherent phase analysis unit 11 to respectively acquire data and analyze phase, and then enters the correlation analysis unit 12. The second pulse laser 13 emits laser pulse and enters the sensing optical fiber 3 cable through the second optical fiber coupler 4, the transmission light of the sensing optical fiber 3 enters the second polarization beam splitter 14 through the first optical fiber coupler 2 and is divided into two paths, the first path enters the second polarization optical fiber coupler 16 through the second optical fiber polarization controller 15, and the other path enters the second polarization optical fiber coupler 16 through the second compensation optical fiber 17. The output light of the second polarization fiber coupler 16 is converted into an electrical signal by the second photodetector 18, and then sequentially passes through the second data acquisition unit 19 and the second correlation phase analysis unit 20 to perform data acquisition and phase analysis, respectively, and then enters the correlation analysis unit 12.
In one embodiment, the monitoring system of the present invention further comprises a Porro delay determination positioning unit 22, a vibration characteristic analysis unit 23 and a display storage unit 24. The two paths of signals are analyzed by the correlation analysis unit 12 and then sequentially subjected to time delay judgment positioning unit 22 and vibration characteristic analysis unit 23 to obtain external disturbance positions and disturbance signal characteristics, and finally the external disturbance positions and the disturbance signal characteristics enter the display storage unit 24 to display and store the final results.
The first pulse laser 1 generates high-power laser pulses, the high-power laser pulses enter the sensing optical cable 3 through the first optical fiber coupler 2 and then propagate forwards along the sensing optical cable 3, in the propagation process, due to the birefringence effect of the sensing optical cable, when external vibration and sound disturbance actions are used for sensing the optical cable, the polarization states of the laser pulses transmitted and output through the sensing optical cable 3 are changed, the transmitted laser pulses enter the first polarization beam splitter 5 through the second optical fiber coupler 4 and then are divided into two paths of linearly polarized light with mutually perpendicular vibration directions, one path of the linearly polarized light enters the first polarization optical fiber coupler 7 after the deflection direction of the first path of the linearly polarized light is changed through the first polarization optical fiber coupler 6, the other path of the linearly polarized light enters the first polarization optical fiber coupler 7 after the delay deviation of the light caused by the first polarization optical fiber coupler 6 is compensated through the first compensating optical fiber 8, the vibration directions of the two paths of light are parallel due to polarization control, so that the coherent conditions are met and interference is generated at the first polarization optical fiber coupler 7, and the first optical detector 9 converts interference light signals into electric signals, and then sequentially analyzes the changes of the signals through the first data acquisition unit 10 and the first coherent phase analysis unit 11. Meanwhile, the second pulse laser 13 generates high-power laser pulses to perform symmetrical reverse transmission, the high-power laser pulses enter the sensing optical cable 3 through the second optical fiber coupler 4 and then propagate forwards along the sensing optical cable 3, the polarization state of the laser pulses transmitted and output through the sensing optical cable 3 can be changed in the propagation process due to the double refraction effect of the sensing optical cable, the transmitted laser pulses enter the second polarization beam splitter 14 through the first optical fiber coupler 2 and then are divided into two paths of linearly polarized light with mutually perpendicular vibration directions, one path of the linearly polarized light enters the second polarization optical fiber coupler 16 after the deflection direction of the linearly polarized light is changed through the second polarization controller 15, the other path of the linearly polarized light enters the second polarization optical fiber coupler 16 after the optical path delay deviation caused by the second polarization controller 15 is compensated through the second compensating optical fiber 17, the two paths of light meet the coherence condition and interference is generated at the second polarization optical fiber coupler 16, and the second photoelectric detector 18 converts interference light signals into electric signals and then sequentially passes through the second data acquisition unit 19 to perform signal acquisition and the second coherence phase analysis unit 20 to analyze the phase change of the signals. The analysis result obtained by the first coherent phase analysis unit 11 enters the correlation analysis unit 12, the analysis result obtained by the second coherent phase analysis unit 20 also enters the correlation analysis unit 12 through the signal transmission unit 21, the correlation analysis unit carries out correlation analysis and identification on two paths of analysis results, and carries out time delay analysis on two paths of signal changes through the time delay judgment positioning 22 so as to realize disturbance positioning, and on the basis, the analysis and identification are carried out on signal characteristics such as analysis result frequency spectrums through the vibration characteristic analysis 23 so as to determine the external disturbance type and characteristics. Finally, all signals and analysis results thereof are displayed and stored in the display storage 24.
The first pulse laser 1 and the second pulse laser 13 simultaneously emit a series of laser pulses and enter the sensing optical cable 3 from two ends of the sensing optical cable 3 respectively, and the propagation directions in the sensing optical cable 3 are opposite. When any point on the sensing optical cable 3 is subjected to vibration or acoustic disturbance, two pulses with opposite propagation directions passing through the point are influenced, each laser pulse signal can be divided into two linear polarization components with perpendicular vibration directions due to the optical fiber birefringence effect, and the phase difference between the two components is related to the microbending, deformation and other disturbance effects of the optical fiber, but because the two vibration components are perpendicular to each other, the vibration directions of the two components are parallel by rotating one of the vibration directions of the polarization components, the two components can generate superposition interference, and external disturbance is measured by analyzing the phase difference change of interference signals. Based on this, all laser pulses emitted by the first pulse laser 1 are divided into two vertical vibration components by the first polarization beam splitter 5, wherein one component interferes with the other component at the first fiber polarization coupler 7 after rotating the vibration direction by the first fiber polarization controller 6; and all laser pulses emitted by the second pulse laser 13 are divided into two vertical vibration components by the second polarization beam splitter 14, wherein one component generates interference at the second fiber polarization coupler 16 by rotating the vibration direction of the second fiber polarization controller 15 and the other component. Because the interference is the interference between two polarization states of the same signal, the coherence requirement of the optical pulse signal is greatly reduced, and the optical pulse signal can still be coherent even after being transmitted for a very long distance, thereby realizing ultra-long distance distributed sensing. In addition, since the first and second optical fiber polarization controllers 6 and 15 cause an additional optical path between the two components, causing a delay difference in the two component pulse light, the delay difference can be eliminated by the first and second compensation optical fibers 7 and 17, respectively. After photoelectric detection and acquisition, the two groups of interference signal phases and intensity changes at the first optical fiber polarization coupler 7 and the second optical fiber polarization coupler 16 are respectively and synchronously analyzed through the first coherent phase analysis unit 11 and the second coherent phase analysis unit 20, on the basis, the correlation and time delay of the two groups of phase changes are respectively analyzed and compared through the correlation analysis unit 12 and the time delay judging and positioning 22 to realize disturbance positioning, and finally, the signal characteristics such as the frequency spectrum of the interference signal phase changes among different pulses are analyzed and identified through the vibration characteristic analysis 23 to determine the external disturbance type and the external disturbance characteristics.
The embodiment provides a monitoring method based on a distributed sensor, which comprises the following steps:
the first pulse laser 1 is adopted, so that the pulse laser passing through the sensing unit 3 generates first coherent light under the action of a first polarization beam splitter 5, a first optical fiber polarization controller 6, a first polarization optical fiber coupler 7 and a first compensation optical fiber 8;
The second pulse laser 13 is adopted, so that the pulse laser passing through the sensing unit 3 generates second coherent light under the action of a second polarization beam splitter 14, a second optical fiber polarization controller 15, a second polarization optical fiber coupler 16 and a second compensation optical fiber 17;
Carrying out phase analysis on the first coherent light and the second coherent light;
And performing correlation analysis and time delay analysis on the two groups of coherent light subjected to phase analysis to realize disturbance positioning.
The two photoelectric detectors are respectively analyzed to receive the cross correlation of the disturbance characteristics of the light signals transmitted by the two ends of the sensing optical fiber, whether the light signals are the same disturbance signal is analyzed, identified and confirmed, and the disturbance occurrence position is confirmed by analyzing the time delay of the two signals on the basis.
The monitoring method of the embodiment further comprises the following steps: and analyzing and identifying the phase change spectrum signal characteristics of the interference signals among different pulses so as to identify the external disturbance source.
The method for analyzing and identifying the phase change spectrum signal characteristics of the interference signals among different pulses comprises the following steps:
Demodulating a series of pulse coherent optical signal phases in sequence;
The change rule and trend of the phase signal are obtained by difference through signals between adjacent pulses and equidistant pulses respectively, and the frequency spectrum characteristics of the phase signal change are analyzed;
and matching the spectrum characteristics obtained through analysis with the set disturbance type to obtain the type of the disturbance source. The set disturbance sources are such as excavation, vehicle running, earthquakes, structural cracking, landslides, falling rocks, and the like.
Claims (10)
1. A distributed sensor-based monitoring system, comprising:
a sensing unit (3) in which an optical fiber sensor is arranged;
The first coherent light generation unit comprises a first pulse laser (1), a first polarization beam splitter (5), a first optical fiber polarization controller (6), a first polarization optical fiber coupler (7) and a first compensation optical fiber (8); the pulse light signal generated by the first pulse laser (1) enters the sensing unit (3) and then enters the first polarization beam splitter (5); the first polarization beam splitter (5) divides an incoming optical signal into two paths of linearly polarized light output with mutually perpendicular vibration directions, a first path of the linearly polarized light output enters the first optical fiber polarization controller (6) to rotate in the vibration direction and be parallel to the vibration direction of a second path of the linearly polarized light output, and the second path of the linearly polarized light output enters the first compensation optical fiber (8) to perform phase compensation and has the same phase as the first path of the linearly polarized light output; the first path of output rotated by the first optical fiber polarization controller (6) and the second path of output compensated by the first compensation optical fiber (8) enter a first polarization optical fiber coupler (7) to be coupled to form first coherent light;
a first coherent phase analysis unit (11) that performs phase analysis on the first coherent light generated by the first coherent light generation unit;
The second coherent light generation unit comprises a second pulse laser (13), a second polarization beam splitter (14), a second optical fiber polarization controller (15), a second polarization optical fiber coupler (16) and a second compensation optical fiber (17); the pulse light signal generated by the second pulse laser (13) enters the sensing unit (3) and then enters the second polarization beam splitter (14); the second polarization beam splitter (14) divides an incoming optical signal into two paths of linearly polarized light output with mutually perpendicular vibration directions, a first path of the linearly polarized light output enters the second optical fiber polarization controller (15) to rotate in the vibration direction and be parallel to the vibration direction of a second path of the linearly polarized light output, and a second path of the linearly polarized light output enters the second compensation optical fiber (17) to perform phase compensation and has the same phase as that of the first path of the linearly polarized light output; the first path of output rotated by the second optical fiber polarization controller (15) and the second path of output compensated by the second compensation optical fiber (17) enter a second polarization optical fiber coupler (16) to be coupled to form second coherent light;
A second coherent phase analysis unit (20) that performs phase analysis on the second coherent light generated by the second coherent light generation unit;
And a correlation analysis unit (12) that performs correlation analysis on the analysis results of the first coherent phase analysis unit (11) and the second coherent phase analysis unit (20).
2. The monitoring system of claim 1, wherein the monitoring system further comprises:
A time delay determination positioning unit (22) and a vibration characteristic analysis unit (23); the time delay judging and positioning unit (22) analyzes and compares the correlation of the two groups of phase changes and the time delay to realize disturbance positioning; the vibration characteristic analysis unit (23) analyzes and identifies signal characteristics such as phase change frequency spectrums of interference signals among different pulses so as to determine the external disturbance type and characteristics.
3. The monitoring system according to claim 1, characterized in that a first optical fiber coupler (2) is connected to the front end of the sensing unit (3), and a second optical fiber coupler (4) is connected to the rear end of the sensing unit (3); the output of the first pulse laser 1 enters the sensing unit (3) through the first optical fiber coupler (2) and is output from a second optical fiber coupler (4); the output of the second pulse laser (13) enters the sensing unit (3) through the second optical fiber coupler (4) and is output from the first optical fiber coupler (2).
4. The monitoring system according to claim 1, wherein the first coherent light generating unit further comprises a first photodetector (9) and a first data acquisition unit (10); the first photoelectric detector (9) converts first coherent light generated by the first polarization optical fiber coupler (7) into an electric signal and then enters the first data acquisition unit (10).
5. The monitoring system according to claim 1, characterized in that the second coherent light generating unit further comprises a second photodetector (18) and a second data acquisition unit (19); the second photodetector (18) converts the second coherent light generated by the second polarization fiber coupler (16) into an electric signal and then enters the second data acquisition unit (19).
6. Monitoring system according to claim 1, characterized in that the sensing unit (3) is a sensing cable.
7. A method of monitoring a monitoring system based on a distributed sensor according to any one of claims 1-6, comprising:
The method comprises the steps that a first pulse laser (1) is adopted, so that pulse laser passing through a sensing unit (3) generates first coherent light under the action of a first polarization beam splitter (5), a first optical fiber polarization controller (6), a first polarization optical fiber coupler (7) and a first compensation optical fiber (8);
A second pulse laser (13) is adopted, so that the pulse laser passing through the sensing unit (3) generates second coherent light under the action of a second polarization beam splitter (14), a second optical fiber polarization controller (15), a second polarization optical fiber coupler (16) and a second compensation optical fiber (17);
Carrying out phase analysis on the first coherent light and the second coherent light;
And performing correlation analysis and time delay analysis on the two groups of coherent light subjected to phase analysis to realize disturbance positioning.
8. The method of claim 7, wherein the correlation analysis and the time delay analysis are performed on the two sets of coherent light beams subjected to phase analysis to achieve disturbance localization, wherein the method comprises: the two photoelectric detectors are respectively analyzed to receive the cross correlation of the disturbance characteristics of the light signals transmitted by the two ends of the sensing optical fiber, whether the light signals are the same disturbance signal is analyzed, identified and confirmed, and the disturbance occurrence position is confirmed by analyzing the time delay of the two signals on the basis.
9. The method of monitoring of claim 7, further comprising:
And analyzing and identifying the phase change spectrum signal characteristics of the interference signals among different pulses so as to identify the external disturbance source.
10. The method of claim 9, wherein the method for analyzing and identifying the phase change spectrum signal characteristics of the interference signals between different pulses is:
Demodulating a series of pulse coherent optical signal phases in sequence;
The change rule and trend of the phase signal are obtained by difference through signals between adjacent pulses and equidistant pulses respectively, and the frequency spectrum characteristics of the phase signal change are analyzed;
And matching the spectrum characteristics obtained through analysis with the set disturbance type to obtain the type of the disturbance source.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210318122.XA CN114777899B (en) | 2022-03-29 | 2022-03-29 | Monitoring system and method based on distributed sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210318122.XA CN114777899B (en) | 2022-03-29 | 2022-03-29 | Monitoring system and method based on distributed sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114777899A CN114777899A (en) | 2022-07-22 |
| CN114777899B true CN114777899B (en) | 2024-04-26 |
Family
ID=82424554
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210318122.XA Active CN114777899B (en) | 2022-03-29 | 2022-03-29 | Monitoring system and method based on distributed sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114777899B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2647560A1 (en) * | 1989-05-23 | 1990-11-30 | Thomson Csf | DEVICE FOR READING POLARIMETRIC AND INTERFEROMETRIC SENSORS |
| CN103245299A (en) * | 2013-05-14 | 2013-08-14 | 东南大学 | High-spatial-resolution optical fiber sensing system based on wavelength tunable laser |
| CN104089636A (en) * | 2014-07-15 | 2014-10-08 | 鞍山鹏泽伟业科技有限公司 | Double-peak stimulative type monitor based on Brillouin scattering |
| CN106525362A (en) * | 2016-12-02 | 2017-03-22 | 山东省科学院激光研究所 | Fiber optic distributed sensing monitoring system |
| CN206161145U (en) * | 2016-11-04 | 2017-05-10 | 安徽师范大学 | Distributed optical fiber vibration sensing system |
| CN106768278A (en) * | 2017-01-06 | 2017-05-31 | 天津大学 | A kind of distributed optical fiber vibration and the double physical quantity sensing positioning systems of temperature |
| CN108759884A (en) * | 2018-05-22 | 2018-11-06 | 南京大学 | Eliminate the distributed dim light grid array sensor-based system and method that polarization decay influences |
| CN109596576A (en) * | 2017-09-30 | 2019-04-09 | 清华大学 | Nanometer light field spin-orbit interaction measuring system and method |
| CN113532414A (en) * | 2021-08-10 | 2021-10-22 | 杭州友孚科技有限公司 | Interference type fiber-optic gyroscope and dual-port differential noise suppression method thereof |
| CN113686366A (en) * | 2021-07-30 | 2021-11-23 | 南方科技大学 | Optical frequency domain reflectometer device based on Fourier domain mode locking and measuring method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101600968B (en) * | 2006-12-22 | 2013-01-02 | Abb研究有限公司 | Optical voltage sensor |
| FR3017945B1 (en) * | 2014-02-26 | 2017-07-28 | Ixblue | INTERFEROMETRIC MEASURING DEVICE |
-
2022
- 2022-03-29 CN CN202210318122.XA patent/CN114777899B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2647560A1 (en) * | 1989-05-23 | 1990-11-30 | Thomson Csf | DEVICE FOR READING POLARIMETRIC AND INTERFEROMETRIC SENSORS |
| CN103245299A (en) * | 2013-05-14 | 2013-08-14 | 东南大学 | High-spatial-resolution optical fiber sensing system based on wavelength tunable laser |
| CN104089636A (en) * | 2014-07-15 | 2014-10-08 | 鞍山鹏泽伟业科技有限公司 | Double-peak stimulative type monitor based on Brillouin scattering |
| CN206161145U (en) * | 2016-11-04 | 2017-05-10 | 安徽师范大学 | Distributed optical fiber vibration sensing system |
| CN106525362A (en) * | 2016-12-02 | 2017-03-22 | 山东省科学院激光研究所 | Fiber optic distributed sensing monitoring system |
| CN106768278A (en) * | 2017-01-06 | 2017-05-31 | 天津大学 | A kind of distributed optical fiber vibration and the double physical quantity sensing positioning systems of temperature |
| CN109596576A (en) * | 2017-09-30 | 2019-04-09 | 清华大学 | Nanometer light field spin-orbit interaction measuring system and method |
| CN108759884A (en) * | 2018-05-22 | 2018-11-06 | 南京大学 | Eliminate the distributed dim light grid array sensor-based system and method that polarization decay influences |
| CN113686366A (en) * | 2021-07-30 | 2021-11-23 | 南方科技大学 | Optical frequency domain reflectometer device based on Fourier domain mode locking and measuring method |
| CN113532414A (en) * | 2021-08-10 | 2021-10-22 | 杭州友孚科技有限公司 | Interference type fiber-optic gyroscope and dual-port differential noise suppression method thereof |
Non-Patent Citations (2)
| Title |
|---|
| In-Fiber Dispersion Compensated Polarizer and Mode-Locked Fiber Laser Application;Jie Hu等;IEEE Photonics Technology Letters;20200316;第510 – 513页 * |
| 光纤分布式声波传感器原理与应用;何祖源等;激光与光电子学进展;20211231;第11-25页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114777899A (en) | 2022-07-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Liu et al. | Advances in phase-sensitive optical time-domain reflectometry | |
| CN108286992B (en) | Distributed optical fiber acoustic sensing device and method based on digital double-chirp pulse modulation | |
| CN101764646B (en) | Wavelength-encoding optical time domain reflection test device and measurement method thereof | |
| US4420260A (en) | Interferometer transmitting the useful phase information through optical fibres | |
| CN105466548A (en) | Phase sensitive optical time domain reflection fiber sensing system positioning method | |
| US20030043697A1 (en) | Apparatus and method for processing optical signals from two delay coils to increase the dynamic range of a sagnac-based fiber optic sensor array | |
| CN102639966A (en) | Optical sensor and method of use | |
| CN101893475B (en) | A kind of distributed optical fiber vibration sensing system based on fiber delay line | |
| CN111308547B (en) | Six-dimensional seismic wave measuring device based on composite interferometer | |
| EP1423986B1 (en) | Apparauts and method for processing optical signals from two delay coils to increase the dynamic range of a sagnac-based fiber optic sensor array | |
| US6678211B2 (en) | Amplified tree structure technology for fiber optic sensor arrays | |
| CN109058054A (en) | A kind of the bolt on-line monitoring system and method for wind power generator group | |
| JP3147616B2 (en) | Distributed waveguide sensor | |
| CN104296783A (en) | Sensor detecting method and device for enhanced coherent optical time domain reflection | |
| Chen et al. | Denoising method of the Φ-OTDR system based on EMD-PCC | |
| CN113721287B (en) | Monitoring method and device based on sensing optical fiber | |
| CN107389978A (en) | A kind of weak reflective Bragg gratings accelerometer and its method for sensing | |
| Zhong et al. | Nuisance alarm rate reduction using pulse-width multiplexing Φ-OTDR with optimized positioning accuracy | |
| CN114777899B (en) | Monitoring system and method based on distributed sensor | |
| CN114993448B (en) | Long-distance distributed vibration monitoring device and monitoring method | |
| AU2020103312A4 (en) | A sensitivity enhanced type optical time domain reflection distributed Michelson interferometer based on a dual-core optical fiber | |
| CN113503955A (en) | Optical fiber hydrophone based on optical frequency domain reflection technology | |
| CN112504433A (en) | Temperature self-reference sensitivity tunable optical fiber distributed vibration detection device and method | |
| EP1423987B1 (en) | Amplified tree structure technology for fiber optic sensor arrays | |
| CN115752696A (en) | Distributed optical fiber vibration sensing system based on forward transmission and signal processing 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 |