CN106483199A - A kind of acoustic emission signal detecting system based on coupling bragg grating - Google Patents
A kind of acoustic emission signal detecting system based on coupling bragg grating Download PDFInfo
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- CN106483199A CN106483199A CN201610893735.0A CN201610893735A CN106483199A CN 106483199 A CN106483199 A CN 106483199A CN 201610893735 A CN201610893735 A CN 201610893735A CN 106483199 A CN106483199 A CN 106483199A
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- bragg grating
- signal
- acoustic emission
- coupling
- laser
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/14—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object using acoustic emission techniques
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- 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
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/22—Details, e.g. general constructional or apparatus details
- G01N29/24—Probes
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/028—Material parameters
- G01N2291/0289—Internal structure, e.g. defects, grain size, texture
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/26—Scanned objects
- G01N2291/262—Linear objects
Abstract
The invention provides a kind of acoustic emission signal detecting system based on coupling bragg grating, including flexible acoustic emission signal detection substrate diaphragm；The bragg grating being connected with described flexibility acoustic emission substrate diaphragm, realizes the acousto-optic modulation to laser signal for the mechanical elasticity ripple；The photo-coupler connecting described bragg grating and mating bragg grating, senses laser for positive input reference laser, reverse transfer；The LD LASER Light Source being connected with described photo-coupler, for producing reference laser signal to be modulated；The coupling bragg grating being connected with described photo-coupler, for entering traveling optical signal matching detection with sensing laser；The photodetector being connected with described coupling bragg grating, realizes the opto-electronic conversion of coupling optical signal；The signal preamplifier being connected with described photodetector, realizes conditioning, the amplification of low light signals.
Description
Technical field
The present invention relates to sensory field of optic fibre, particularly to a kind of acousto-optic electroacoustic three-level for sonar leak detector
The adaptive device of conversion, realizes what the Weak Ultrasonic signal caused to the leakage of air-liquid body in severe, complex environment was detected
Method
Background technology
At present, the tiny leakage of the pressure pipeline such as oil, gas carries out leak detection is a global difficult problem, and sonar leak detector utilizes sonar
Technology, to leakage failure, unique faint acoustic emission signal is detected, analyzed and is processed, and is just used widely.
But some special occasions, equipment or pipeline are wrapped up by deadener, or it is dipped in corrosivity oil, water, in vapour, passes
System ultrasonic probe is difficult to work.Grating sensor can be accessed sonar leak detection by the sonar leak detector adaption system of present invention design
The adaptive device of instrument, by light, electricity, the conversion of sound two-stage O_3-BAC, is connected convenient to grating sensing and sonar leak detector, is not destroying
More rich sensing modality is provided, thus realizing limited space, sound wave is obstructed, bad environments condition on the premise of former instrument structure
Under leakage ultrasound detection, there is higher engineering application value.Laser be used for gas detecting in environment measuring and analysis and
The aspects such as various industrial stokehold have significant application value.
Accordingly, it would be desirable to a kind of can how using sonar technique come the detection method of accurate detection acoustic emission signal and system.
Content of the invention
In order to solve the above problems, according to an aspect of the invention, it is provided a kind of be based on coupling bragg fiber light
The acoustic emission signal detecting system of grid, described system includes band bragg grating villous, the optical coupling being sequentially connected
Device, coupling bragg grating, light source, photodetector, signal preamplifier, electric signal output module, electroacoustic output
Module and sonar leak detector, wherein said band Bragg grating villous includes flexible acoustic emission signal detection basement membrane
The tapetum of piece, the bragg grating being attached on described substrate diaphragm and the setting of described bragg grating, uses
In realizing the acousto-optic modulation to laser signal for the mechanical elasticity ripple；
Described photo-coupler connects described bragg grating and mate bragg grating, inputs for forward direction
Reference laser, reverse transfer sensing laser；
Described light source is connected with described photo-coupler, for producing reference laser signal to be modulated；
Described coupling bragg grating is connected with described photo-coupler, mates for entering traveling optical signal with sensing laser
Detection；
Described photodetector is connected with described coupling bragg grating, realizes the opto-electronic conversion of coupling optical signal；
Described signal preamplifier is connected with described photodetector, realizes conditioning, the amplification of low light signals；
Described electric signal output module is connected with described signal preamplifier, is suitable for sonar leak detector for generation defeated
The multiple electrical signal form entering；
Described electroacoustic output module is connected with described signal preamplifier, produces and is suitable for the inspection of sonar leak detector pick-up head
The pseudo- sound source surveyed.
Preferably, signal flow path switch be acousto-optic conversion, opto-electronic conversion, electroacoustic change three level conversions.
Preferably, described substrate diaphragm adopts ultra-thin PVC material.
Preferably, using electrospinning fibre as acoustic matching material fluff structures, absorb transmission acoustical signal.
Preferably, the length using electrospinning fibre electrospinning fibre fluff structures is 1-2mm.
Preferably, described electroacoustic output module adopts piezoelectric transducer.
According to the acoustic emission signal detecting system based on coupling bragg grating for the present invention, detection sensitivity is high,
On the premise of not destroying existing sonar leak detector configurations, expanded its application under high corrosion, high humidity hot environment it is easy to
In multiple applications.
It should be appreciated that aforementioned description substantially and subsequently detailed description are exemplary illustration and explanation, should not
As the restriction to the claimed content of the present invention.
Brief description
With reference to the accompanying drawing enclosed, the more purpose of the present invention, function and advantage will be as follows by embodiment of the present invention
Description is illustrated, wherein：
Fig. 1 schematically shows the system knot of adaption system of hunting leak according to the coupling bragg grating formula sonar of the present invention
Structure schematic diagram；
Fig. 2 schematically shows the substrate diaphragm structure schematic diagram according to the present invention.
Specific embodiment
Hereinafter, embodiments of the invention will be described with reference to the drawings.In the accompanying drawings, identical reference represent identical
Or similar part, or same or similar step.
By reference to one exemplary embodiment, the purpose of the present invention and function and the side for realizing these purposes and function
Method will be illustrated.However, the present invention is not limited to one exemplary embodiment disclosed below；Can by multi-form Lai
It is realized.The essence of description is only to aid in the detail of the various equivalent modifications Integrated Understanding present invention.
It is described in detail with reference to schematic diagram for the present invention, when describing the embodiment of the present invention in detail, for purposes of illustration only, representing
The profile of device architecture can be disobeyed general ratio and be made partial enlargement, and described schematic diagram is example, and its here should not limit
The scope of protection of the invention processed.Additionally, the three-dimensional space of length, width and depth should be comprised in actual fabrication.
The invention provides a kind of coupling bragg grating formula sonar leak detection adaption system, by acousto-optic-electric
Sound three level conversion, realizes the sensing of the acoustic emission signal of pipeline tiny leakage generation, and provides adaptation to connect for existing sonar leak detector
Mouthful, on the premise of not destroying existing sonar leak detector configurations, expand its application under high corrosion, high humidity hot environment.
The method and system are not limited solely to the detection to pipe leakage, also can easily be generalized to and other sonar leak detectors are answered
With in field.
The invention provides a kind of acoustic emission signal based on coupling bragg grating of utilization fine hair optical grating construction
Detecting system, Fig. 1 schematically shows the coupling bragg grating formula sonar of the utilization fine hair optical grating construction according to the present invention
The system structure diagram of leak detection adaption system.Described system 100 includes the band bragg fiber villous light being sequentially connected
Grid 101, photo-coupler 102, coupling bragg grating 103, light source 104, photodetector 105, signal preamplifier
106th, electric signal output module 107, electroacoustic output module 108 and sonar leak detector 109.
Specifically, bragg grating 101 (in figure show FBG1 101) villous, described Bragg grating are carried
101 include flexible acoustic emission signal detects substrate diaphragm and the bragg fiber being connected with described flexibility acoustic emission substrate diaphragm
Grating, realizes the acousto-optic modulation to laser signal for the mechanical elasticity ripple；The concrete structure of Bragg grating 101 will be below with reference to figure
2 detailed descriptions.
Photo-coupler 102 connects described bragg grating 101 and mates bragg grating 103, for forward direction
Input reference laser, reverse transfer sensing laser；
Light source 104 is connected with described photo-coupler 102, preferably LD LASER Light Source, swashs for producing benchmark to be modulated
Optical signal；
Coupling bragg grating 103 is connected with described photo-coupler 102, for entering traveling optical signal with sensing laser
Collating is surveyed；
Photodetector 105 is connected with described coupling bragg grating 103, and the photoelectricity realizing coupling optical signal turns
Change；
Signal preamplifier 106 is connected with described photodetector 105, realizes conditioning, the amplification of low light signals；
Electric signal output module 107 is connected with described signal preamplifier 106, is suitable for sonar leak detector for producing
Multiple electrical signal form of 109 inputs；
Electroacoustic output module 108 is connected with described signal preamplifier 106, produces and is suitable for input to sonar leak detector
The pseudo- sound source of 109 pick-up head detections.
According to one embodiment of present invention, signal flow path switch be acousto-optic conversion, opto-electronic conversion, electroacoustic conversion three-level turn
Change.
Preferably, described electroacoustic output module 108 adopts piezoelectric transducer.
According to the present invention, the core diameter of bragg fiber is determined by the Active Optical Fiber being adopted, covering core diameter is preferably 125 μ
M, the core diameter of fiber core can select 4 μm, 8 μm or 10 μm, preferably 10/125 μm.According to the specific embodiment of the invention, light
Fine type should be matched with the pumping wavelength of light source 104.For example, according to one embodiment of present invention, bragg fiber choosing
From Er-doped fiber, Yb dosed optical fiber or erbium-ytterbium co-doped fiber.
The pumping wavelength that Er-doped fiber is mated can adopt 980nm or 1480nm, and the pumping wavelength of Yb dosed optical fiber can adopt
976nm or 915nm, the pumping wavelength of erbium-ytterbium co-doped fiber can adopt 976nm, further determines that light according to wavelength and core diameter parameter
The parameter of bonder 102.The optical maser wavelength of final outgoing in the certain gain ranging of Active Optical Fiber (as 1530-1560nm) by cloth
The reflection wavelength of glug fiber grating determines.The typical exit wavelength of Yb dosed optical fiber is 1535nm, the typical exit of Er-doped fiber
Wavelength is 1064nm, and the typical exit wavelength of erbium-ytterbium co-doped fiber is 1550nm.
For example, in the present embodiment, if being 10/125 μm of Er-doped fiber as gain media from core diameter.Light source 104 is defeated
Go out wavelength 976nm, FBG selection range is 1530nm-1560nm, laser output can be obtained within the range.If selecting in experiment
For 10/125 μm of Yb dosed optical fiber as gain media, LD tail optical fiber need to choose same model core diameter to core diameter.LD is that 915nm single mode is defeated
Go out, FBG chooses near 1064nm, laser output can be obtained within the range.
The coupling bragg grating formula sonar leak detection of the utilization fine hair optical grating construction according to the present invention shown in Fig. 1 is suitable
The operation principle of match system is as follows：
Light source 104 sends laser, is coupled to band bragg grating 101 villous, projection by photo-coupler 102
To on object to be detected, laser is back to bragg grating 101 through detected object, then couples through photo-coupler 102
To coupling bragg grating 103.The optical signal of coupling bragg grating 103 modulation output is imported into photodetection
Device 105 is converted into the signal of telecommunication, is then passed through the amplification of signal preamplifier 106, is input to electric signal output module 107 and electricity
Voice output module 108, then be input to sonar leak detector 109 and detected.
Fig. 2 schematically shows the coupling bragg grating formula sonar inspection of the utilization fine hair optical grating construction according to the present invention
Structural representation with bragg grating villous in leakage adaption system.
As shown in Fig. 2 carrying bragg grating 101 villous to include bragg grating 201, tapetum 202
And substrate diaphragm 203.This substrate diaphragm 203 for example can adopt flexible PVC substrate, is pasted with bragg grating thereon
201, tapetum 202 is provided with bragg grating 201, tapetum 202 preferably can adopt electrospinning fibre fine hair
Structure.
Can be made by following process according to the tapetum 202 of the present invention, to be formed at bragg grating 201
On.For example, by being loaded with polymer solution or the fused solution of charging in injection apparatus.Under DC Electric Field, by surface
Tension force effect and be maintained at the macromolecule drop at nozzle, electric field induction lower surface assemble electric charge, opened with surface by one
The contrary electric field force of force direction.When electric field gradually strengthens, drop at nozzle is elongated as taper by spherical, is formed so-called
Taylor cone.And when electric field intensity increases to a marginal value, electric field force will overcome the surface tension of liquid, from taylor cone
Spray.Injection stream occurs to shake and unstable, the scrambling screw of generation very high frequency in the presence of high electric field.In height
In speed concussion, injection stream is drawn and attenuated rapidly, and solvent also volatilizees rapidly, ultimately forms the nano level fiber of diameter, and with random
Mode is scattered on collection device, forms copolymer of fiber suede batt.
According to one embodiment of present invention, described substrate diaphragm adopts ultra-thin PVC material, greatly reduces to table to be measured
The impact in face, such as thickness are between 10nm-100mm.
According to one embodiment of present invention, described substrate diaphragm, by the use of electrospinning fibre as acoustic matching material, absorbs
Transmission acoustical signal.Electrospinning fibre adopts and substrate diaphragm identical PVC, forms nanoscale fine hair by high-pressure electrostatic wire drawing, right
The transmitted acoustic pulse of substrate is absorbed, and prevents multiple reflections and causes the conditions of streaking of acoustic emission signal.
According to one embodiment of present invention, the length of electrospinning fibre fluff structures is 1-2mm.
According to the acoustic emission signal detecting system based on coupling bragg grating for the present invention, detection sensitivity is high,
On the premise of not destroying existing sonar leak detector configurations, expanded its application under high corrosion, high humidity hot environment it is easy to
In multiple applications.
Explanation in conjunction with the present invention disclosing here and practice, the other embodiment of the present invention is for those skilled in the art
All will be readily apparent and understand.Illustrate and embodiment be to be considered only as exemplary, the true scope of the present invention and purport equal
It is defined in the claims.
Claims (6)
1. a kind of acoustic emission signal detecting system based on coupling bragg grating, described system includes the band being sequentially connected
Bragg grating villous, photo-coupler, coupling bragg grating, light source, photodetector, advance signal are put
Big device, electric signal output module, electroacoustic output module and sonar leak detector, wherein
Described band Bragg grating villous includes flexible acoustic emission signal detection substrate diaphragm, is attached at described substrate diaphragm
On bragg grating and described bragg grating setting tapetum, be used for realizing mechanical elasticity ripple to laser
The acousto-optic modulation of signal；
Described photo-coupler connects described bragg grating and mates bragg grating, for positive input reference
Laser, reverse transfer sensing laser；
Described light source is connected with described photo-coupler, for producing reference laser signal to be modulated；
Described coupling bragg grating is connected with described photo-coupler, mates inspection for entering traveling optical signal with sensing laser
Survey；
Described photodetector is connected with described coupling bragg grating, realizes the opto-electronic conversion of coupling optical signal；
Described signal preamplifier is connected with described photodetector, realizes conditioning, the amplification of low light signals；
Described electric signal output module is connected with described signal preamplifier, is suitable for the input of sonar leak detector for producing
Multiple electrical signal form；
Described electroacoustic output module is connected with described signal preamplifier, produces and is suitable for the detection of sonar leak detector pick-up head
Pseudo- sound source.
2. acoustic emission signal detecting system as claimed in claim 1, its signal flow path switch be acousto-optic conversion, opto-electronic conversion,
Electroacoustic changes three level conversions.
3. acoustic emission signal detecting system as claimed in claim 1, described substrate diaphragm adopts ultra-thin PVC material.
4. acoustic emission signal detecting system as claimed in claim 1, using electrospinning fibre as acoustic matching material fluff structures,
Absorb transmission acoustical signal.
5. acoustic emission signal detecting system as claimed in claim 4, using the length of electrospinning fibre electrospinning fibre fluff structures
For 1-2mm.
6. acoustic emission signal detecting system as claimed in claim 1, described electroacoustic output module adopts piezoelectric transducer.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111449629A (en) * | 2020-04-28 | 2020-07-28 | 北京信息科技大学 | Optical coherence elastography method and device |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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