CN107167226B - Optical fiber grating sonic device and acoustic pressure sensor-based system - Google Patents
Optical fiber grating sonic device and acoustic pressure sensor-based system Download PDFInfo
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- CN107167226B CN107167226B CN201710387983.2A CN201710387983A CN107167226B CN 107167226 B CN107167226 B CN 107167226B CN 201710387983 A CN201710387983 A CN 201710387983A CN 107167226 B CN107167226 B CN 107167226B
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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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Abstract
The present invention provides a kind of optical fiber grating sonic device and acoustic pressure sensor-based systems, belong to fiber optic sensor technology field.The optical fiber grating sonic device includes pedestal, the quick cylinder of sound, balance pipe and fiber grating.Intercommunicating pore is equipped in pedestal, the first end of the quick cylinder of sound is connect with pedestal, forms a cavity.Balance pipe is set in cavity, and the first opening of balance pipe is connected to intercommunicating pore, and the second opening of balance pipe is connected to cavity.Fiber grating is set in cavity, and the axial deformation occurred under sound pressure signal to be measured effect for measuring the quick cylinder of sound, output carries the signal light of sound pressure signal to be measured.Optical fiber grating sonic device provided by the invention is not only small in size, structure is simple, is conducive to the miniaturization of optical fiber grating sonic device, additionally it is possible to effectively balance hydrostatic pressing, improve the frequency measurement range of resistance to hydrostatic pressure ability and sound pressure signal.
Description
Technical field
The present invention relates to fiber optic sensor technology fields, pass in particular to a kind of optical fiber grating sonic device and acoustic pressure
Sensing system.
Background technique
Fibre optical sensor is relative to conventional electromagnetism class sensor, in sensitivity, Larger Dynamic range, reliability, multiplexing energy
Power etc. has apparent advantage, becomes an important directions of high-performance sensors development.Fibre optic hydrophone is to utilize light
The fine mudulation effect for passing light characteristic and the effect generation of ambient enviroment acoustic pressure, detects the instrument of sound in water.With traditional electricity
Magnetic class hydrophone is compared, fibre optic hydrophone have the advantage that sound pressure sensitivity it is high, not by electromagnetic interference, small in size, waterproof is resistance to
The advantages that burn into has both sensing and transmission, has in fields such as ocean oil and gas resource exploration, underwater navigation, ocean national defence
There is good application prospect.
The main technical schemes of fibre optic hydrophone include intensity modulation type, interference formula, fiber Bragg grating type etc., optical fiber light at present
Grating hydrophone due to high sensitivity, it is small in size, be easy to the advantages such as wavelength-division multiplex, for manufacture it is highly sensitive, ultra-fine, light
Just, Quick distributor underwater sound sensor array provides possibility, and with ship underwater acoustic measurement, the fields such as island, harbour are quickly guarded against have
Broad application prospect.
The existing balance hydrostatic profile optical fiber grating sonic device with air bag is one air bag of connection on the cavity of hydrophone,
To reach the pressure equilibrium inside and outside hydrophone cavity.This hydrophone structure is complicated, and volume is heavy, is unfavorable for hydrophone structure
Miniaturization, and be easy destroyed, operating depth is limited.
Summary of the invention
In consideration of it, the purpose of the present invention is to provide a kind of optical fiber grating sonic device and acoustic pressure sensor-based system, it can be effective
Ground improves the above problem.
To achieve the goals above, The technical solution adopted by the invention is as follows:
In a first aspect, the embodiment of the invention provides a kind of optical fiber grating sonic devices, comprising: the quick cylinder of pedestal, sound, balance pipe
And fiber grating.Pedestal is equipped with intercommunicating pore, and the first end of the quick cylinder of sound is connect with the pedestal, forms a cavity.Balance
Pipe is set in the cavity, and the first opening of the balance pipe is connected to the intercommunicating pore, the second opening of the balance pipe
It is connected to the cavity, so that flowing into the cavity through the balance pipe after external fluid is entered by the intercommunicating pore.Optical fiber
Grating is set in the cavity, and the first tail optical fiber of the fiber grating is fixedly connected with the pedestal, the fiber grating
Second tail optical fiber is fixedly connected with the second end of the quick cylinder of the sound, and the fiber grating is for measuring the quick cylinder of the sound in acoustic pressure to be measured
The axial deformation occurred under signal function, output carry the signal light of the sound pressure signal to be measured.
Further, above-mentioned optical fiber grating sonic device further include: for improving the compressible of the quick cylinder interior media of the sound
The elastic compensating body of property, the elastic compensating body are set in the cavity.
Further, above-mentioned elastic compensating body invests the outer wall of the balance pipe.
Further, above-mentioned fiber grating is located in the balance pipe, and the first tail optical fiber of the fiber grating is pierced by described
First opening is fixedly connected with the pedestal, and the second tail optical fiber of the fiber grating is pierced by second opening and the quick cylinder of the sound
Second end be fixedly connected.
Further, above-mentioned intercommunicating pore include along first direction setting the first inlet opening and in a second direction be arranged the
Two inlet openings, first inlet opening are intersected and are connected to second inlet opening, second inlet opening and the balance pipe
The first open communication so that external fluid by first inlet opening enter after, through second inlet opening, the balance
Pipe flows into the cavity.
Further, said base is cylindrical structure, and the first direction is the radial direction of the pedestal, described the
Two directions are the central axis direction of the pedestal.
Further, one end of said base is provided with boss, and the intercommunicating pore is through the boss and the balance pipe
Connection, the first end of the quick cylinder of sound are open end, and the second end of the quick cylinder of sound is closed end, the open end with it is described convex
Platform connection, to form the cavity.
Further, the quick cylinder of above-mentioned sound is cylindrical structure, and the balance pipe is arranged along the axial direction of the quick cylinder of the sound
In in the cavity.
Further, the wall thickness of the quick cylinder of above-mentioned sound is in the range of 0.5-0.8mm.
Second aspect, the embodiment of the invention also provides a kind of acoustic pressure sensor-based system, including light supply apparatus, demodulating equipment with
And above-mentioned optical fiber grating sonic device.The light supply apparatus and optical fiber of the demodulating equipment with the optical fiber grating sonic device
Grating is optical coupled.The detection light that the light supply apparatus issues enters the fiber grating, the spy reflected by the fiber grating
Light is surveyed as the signal light for carrying sound pressure signal to be measured and is incident on the demodulating equipment, demodulates to obtain through the demodulating equipment to be measured
Acoustic pressure.
Compared with the prior art, optical fiber grating sonic device provided in an embodiment of the present invention has abandoned air bag, using the quick cylinder of sound
As acoustic pressure sensing element, balance pipe and fiber grating are respectively positioned in the quick cylinder of sound, small in size, structure is simple, are conducive to optical fiber light
The miniaturization of grid hydrophone.In addition, the acoustic cavity knot being made up of the cavity of the intercommunicating pore, the quick cylinder of balance pipe harmony that are sequentially communicated
Structure can effectively balance hydrostatic pressing, improve the frequency measurement range of resistance to hydrostatic pressure ability and sound pressure signal.
To enable the above objects, features and advantages of the present invention to be clearer and more comprehensible, preferred embodiment is cited below particularly, and cooperate
Appended attached drawing, is described in detail below.
Detailed description of the invention
In order to illustrate the technical solution of the embodiments of the present invention more clearly, below will be to needed in the embodiment attached
Figure is briefly described, it should be understood that the following drawings illustrates only certain embodiments of the present invention, therefore is not construed as pair
The restriction of range for those of ordinary skill in the art without creative efforts, can also be according to this
A little attached drawings obtain other relevant attached drawings.
Fig. 1 is a kind of structural schematic diagram for optical fiber grating sonic device that first embodiment of the invention provides;
Fig. 2 is the structural schematic diagram of the pedestal in Fig. 1 under the visual angle along Y-axis positive direction;
Fig. 3 is the structural schematic diagram of the pedestal in Fig. 1 under the visual angle along X-axis positive direction;
Fig. 4 is the structural schematic diagram for another optical fiber grating sonic device that first embodiment of the invention provides;
Fig. 5 is the finite element simulation amplitude-frequency characteristic result schematic diagram of the optical fiber grating sonic device shown in Fig. 4;
Fig. 6 is a kind of structural schematic diagram for acoustic pressure sensor-based system that second embodiment of the invention provides.
In figure: 100- optical fiber grating sonic device;110- pedestal;111- intercommunicating pore;The first inlet opening 101-;102- second into
Water hole;112- boss;The first optic fibre hole of 113-;The quick cylinder of 120- sound;121- cavity;The second optic fibre hole of 122-;130- balance pipe;
140- fiber grating;The first tail optical fiber of 141-;The second tail optical fiber of 142-;150- elastic compensating body;10- acoustic pressure sensor-based system;200- light
Source device;300- demodulating equipment.
Specific embodiment
The existing balance hydrostatic profile optical fiber grating sonic device with air bag is one air bag of connection on the cavity of hydrophone,
To reach the pressure equilibrium inside and outside hydrophone cavity.This hydrophone structure is complicated, and volume is heavy, is unfavorable for hydrophone structure
Miniaturization, and be easy destroyed, operating depth is limited, influences practical application.For example, Steven Goodman etc. is proposed
With air bag balance hydrostatic profile optical fiber grating sonic device scheme, air bag volume be 5 times of hydrophone cavity volume when, hydrophone
Theoretical maximum operating depth there was only 50m.In consideration of it, the embodiment of the invention provides a kind of optical fiber grating sonic device and uses
The acoustic pressure sensor-based system of the optical fiber grating sonic device, can effectively improve the existing balance hydrostatic profile fiber grating with air bag
Hydrophone structure is complicated, and volume is heavy, is easy to be destroyed, the limited problem of operating depth.
In order to make the object, technical scheme and advantages of the embodiment of the invention clearer, below in conjunction with the embodiment of the present invention
In attached drawing, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment is
A part of the embodiment of the present invention, instead of all the embodiments.The present invention being usually described and illustrated herein in the accompanying drawings is implemented
The component of example can be arranged and be designed with a variety of different configurations.
Therefore, the detailed description of the embodiment of the present invention provided in the accompanying drawings is not intended to limit below claimed
The scope of the present invention, but be merely representative of selected embodiment of the invention.Based on the embodiments of the present invention, this field is common
Technical staff's every other embodiment obtained without creative efforts belongs to the model that the present invention protects
It encloses.
It should also be noted that similar label and letter indicate similar terms in following attached drawing, therefore, once a certain Xiang Yi
It is defined in a attached drawing, does not then need that it is further defined and explained in subsequent attached drawing.
In the description of the present invention, it should be noted that the instructions such as term " center ", "upper", "lower", "left", "right"
Orientation or positional relationship be based on the orientation or positional relationship shown in the drawings or the invention product using when usually put
Orientation or positional relationship is merely for convenience of description of the present invention and simplification of the description, rather than the device of indication or suggestion meaning or
Element must have a particular orientation, be constructed and operated in a specific orientation, therefore be not considered as limiting the invention.This
Outside, term " first ", " second " etc. are only used for distinguishing description, are not understood to indicate or imply relative importance.
In the description of the present invention, it is also necessary to which explanation is unless specifically defined or limited otherwise, term " setting ",
" installation ", " optical coupled ", " connection " shall be understood in a broad sense.For example, connection may be a fixed connection, it is also possible to detachably connect
It connects, or is integrally connected;It can be mechanical connection, be also possible to be electrically connected;It can be directly connected, intermediate matchmaker can also be passed through
Jie is indirectly connected, and can be the connection inside two elements.Optical coupled between two devices, expression is gone out by one of device
The light penetrated is incident on another device.For the ordinary skill in the art, above-mentioned term can be understood with concrete condition
Concrete meaning in the present invention.
First embodiment
As shown in Figure 1, first embodiment of the invention provides a kind of optical fiber grating sonic device 100, including pedestal 110, sound
Quick cylinder 120, balance pipe 130 and fiber grating 140.The first end of the quick cylinder 120 of sound is connect with pedestal 110, forms a cavity
121.Balance pipe 130 and fiber grating 140 are all set in the cavity 121 of the quick cylinder 120 of sound.Pedestal 110 is equipped with intercommunicating pore 111,
For introducing external fluid into cavity 121.First opening of balance pipe 130 is connected to intercommunicating pore 111, and the of balance pipe 130
Two openings are connected to cavity 121, so that flowing into cavity 121 through balance pipe 130 after external fluid is entered by intercommunicating pore 111.
It should be noted that the quick cylinder 120 of sound can be with pedestal 110 it is integrally formed, be also possible to two it is mutually indepedent
Element.In the present embodiment, since the quick cylinder 120 of sound is made of acoustic sensing material, and pedestal 110 can not need to use sound quick
Sense material is made, for example, can be using metal, plastics etc..Therefore, the quick cylinder 120 of sound and pedestal 110 are preferably mutually independent member
Part.
In the present embodiment, pedestal 110 can be formed by metal material processing.Certainly, the present embodiment is not intended to limit pedestal 110
Material, specifically can according to need and be made of suitable material.Specifically, intercommunicating pore 111 may include along first direction
The first inlet opening 101 being arranged and the second inlet opening 102 being arranged in a second direction.First inlet opening 101 and the second inlet opening
102 intersect and are connected to.At this point, the first open communication of the second inlet opening 102 and balance pipe 130, so that external fluid is by the
After one inlet opening 101 enters, cavity 121 is flowed into through the second inlet opening 102, balance pipe 130.Wherein, first direction and second party
To can be arranged according to the concrete shape of pedestal 110.
In the present embodiment, intercommunicating pore 111 in pedestal 110 can be "T"-shaped intercommunicating pore 111 as shown in Figure 1, i.e., first
Inlet opening 101 and the second inlet opening 102 constitute "T"-shaped intercommunicating pore 111.When pedestal 110 is cylindrical structure, the first inlet opening
101 along pedestal 110 radial direction be arranged, the second inlet opening 102 along pedestal 110 central axis be arranged.For example, the first water inlet
Hole 101 can be the circular through hole for being 2mm along the radial diameter of pedestal 110, and the second inlet opening 102 is along the center of pedestal 110
The diameter of axis is the circular hole of 2mm and is connected to the first inlet opening 101.
The quick cylinder 120 of sound is made of acoustic sensing material, can deform under acoustic pressure effect, for incuding extraneous acoustic pressure letter
Number.Specifically, the quick cylinder 120 of sound can be process using stiff polymer material, for example, can use Young's modulus for
400MPa, density 250kg/m3Hard polyurethane material.And the specific size of the quick cylinder 120 of sound can be set according to specific needs
Meter.For example, size can be with when the quick cylinder 120 of sound is columnar structured are as follows: outer diameter 7mm, it is interior through 5.6mm, wall thickness 0.7mm, cylinder
Long 40mm.In a preferred embodiment of the present invention, in order to improve measurement sensitivity and measurable sound-pressure frequency range, the quick cylinder of sound
120 wall thickness is preferably in the range of 0.5-0.8mm.For example, the wall thickness of the quick cylinder 120 of sound can for 0.5mm, 0.6mm or
0.8mm。
It should be noted that being used in series in order to facilitate optical fiber grating sonic device 100, in the present embodiment, said base
110 preferably cylindrical structures, and the quick cylinder 120 of above-mentioned sound is then preferably columnar structured.Certainly, the quick cylinder 120 of 110 harmony of pedestal
Shape can also design according to specific needs.
In the present embodiment, the quick cylinder 120 of sound is rigidly connected with pedestal 110.Specific connection type can be with are as follows: as shown in Figure 1,
One end of pedestal 110 is provided with boss 112, and intercommunicating pore 111 is connected to through boss 112 with balance pipe 130, and the of the quick cylinder 120 of sound
One end is open end, and the second end of the quick cylinder 120 of sound is closed end, and open end is connect with boss 112, to form cavity 121.Separately
Outside, specifically, the second inlet opening 102 is connected to through boss 112 with balance pipe 130, and the 112 quick cylinder 120 of insertion sound of boss is opened
Mouth end and therewith clamping, so that the outer diameter close-fitting of the boss 112 of the open end internal diameter of the quick cylinder 120 of sound and pedestal 110
Close installation.It should be noted that a kind of pedestal 110 of optical fiber grating sonic device 100 shown in fig. 1 is cylindrical structure.In Fig. 1
Rectangular coordinate system is established by origin of arbitrary point, wherein X-direction is parallel to the central axial direction of pedestal 110, Y-axis side
To the radial direction for being parallel to pedestal 110.Fig. 2 shows the structure of pedestal 110 is shown in Fig. 1 under the visual angle along Y-axis positive direction
It is intended to.Fig. 3 shows the structural schematic diagram of the pedestal 110 in Fig. 1 under the visual angle along X-axis positive direction.
Certainly, other than aforesaid way, the quick cylinder 120 of sound can also be connect with pedestal 110 using other connection types.Example
Such as, the groove being adapted to the open end of the quick cylinder 120 of sound can also be set in one end of pedestal 110, the open end of the quick cylinder 120 of sound is inserted
Enter groove and therewith clamping.Alternatively, can also be connected using thread connecting mode between the quick cylinder 120 of sound and pedestal 110.
In addition, the leakproofness in order to guarantee junction, the quick cylinder 120 of sound and the junction of pedestal 110 can use epoxy glue
Bonding.
In the present embodiment, above-mentioned balance pipe 130 can be rigid metal tube.Certainly, in order to increase the use of balance pipe 130
Service life, balance pipe 130 can preferably use stainless steel tube.In addition, in order to realize preferable resistance to hydrostatic pressure ability and biggish
Frequency measurement range, the value range of 130 internal diameter of balance pipe are preferably 0.5-1mm, and the value range of outer diameter is preferably 2-3mm.
For example, the internal diameter of balance pipe 130 can be 0.5mm, 0.7mm or 1mm, outer diameter can be 2mm, 2.5mm or 3mm.For example, balance
Pipe 130 can use interior through for 0.5mm, outer diameter 2mm, length is the stainless steel tube of 35mm.
Specifically, the mode for realizing that the first opening of balance pipe 130 is connected to intercommunicating pore 111 can be preferred are as follows: balance pipe
The second inlet opening 102, and the hole wall tight fit of the outer wall of balance pipe 130 and the second inlet opening 102 are inserted into 130 one end.At this point,
In order to further consolidate balance pipe 130, balance pipe 130 and pedestal 110 can be welded by being welded.Certainly, in addition to above-mentioned side
Outside formula, can also using other can be realized balance pipe 130 first opening be connected to intercommunicating pore 111 by the way of, for example, it is also possible to
One end of balance pipe 130 is directly welded in the opening of the close cavity 121 of the second inlet opening 102.
Preferably, balance pipe 130 is arranged along the central axis of the quick cylinder 120 of sound.It is understood that when actual fabrication, In
In acceptable error range, the central axis of the extending direction and the quick cylinder 120 of sound of balance pipe 130 may be deviated.
Optical fiber grating sonic device 100 provided in this embodiment passes through intercommunicating pore 111,130 harmony of balance pipe being sequentially communicated
The acoustic cavity structure that quick 120 inner chamber body 121 of cylinder is constituted, can play the role of low-pass filtering, effectively balance hydrostatic pressing, improve
The frequency measurement range of resistance to hydrostatic pressure ability and sound pressure signal.
In the present embodiment, fiber grating 140 is set in above-mentioned cavity 121, is conducive to that fiber grating 140 is protected not to be damaged
It is bad, improve the reliability of hydrophone.Preferably, the grid region of fiber grating 140 is located in balance pipe 130.In order to improve measurement essence
Degree, fiber grating 140 are arranged also along the central axis of the quick cylinder 120 of sound.The first tail optical fiber 141 and pedestal 110 of fiber grating 140
It is fixedly connected, the second tail optical fiber 142 of fiber grating 140 is fixedly connected with the second end of the quick cylinder 120 of sound, and fiber grating 140 is used for
The axial deformation that the quick cylinder 120 of measurement sound occurs under sound pressure signal to be measured effect, output carry the signal light of sound pressure signal to be measured,
Acoustic pressure to be measured is obtained in order to further demodulate the signal light.In the present embodiment, fiber grating 140 can be ordinary optic fibre Bradley
Lattice grating or Active Optical Fiber grating.Wherein, Active Optical Fiber grating includes distributed Blatt reflective (DBR) structure and distributed feed-back
(DFB) structure.
In order to install fiber grating 140, the first optic fibre hole 113, the second end of the quick cylinder 120 of sound are additionally provided in pedestal 110
I.e. closed end is provided with the second optic fibre hole 122.It is understood that when fiber grating 140 is along the central axis of the quick cylinder 120 of sound
When setting, the first optic fibre hole 113 and the second optic fibre hole 122 are arranged also along the central axis of the quick cylinder 120 of sound.Wherein, the first light
Fine hole 113 for drawing the first tail optical fiber 141 of fiber grating 140, and is fixed with the first tail optical fiber 141 of fiber grating 140 and is connected
It connects;Second optic fibre hole 122, for drawing the second tail optical fiber 142 of fiber grating 140, and the second tail optical fiber with fiber grating 140
142 are fixedly connected.For example, the first tail optical fiber 141 and the second tail optical fiber 142 can be correspondingly bonded and fixed to respectively by epoxy glue
In first optic fibre hole 113 and the second optic fibre hole 122.In addition, fiber grating 140 can be made to keep certain when being adhesively fixed
Prestretching, for example, the prestretching of about 100pm can be kept.
In addition, in order to further increase the measurement sensitivity of this optical fiber grating sonic device 100, as shown in figure 4, the present embodiment
The optical fiber grating sonic device 100 of offer further includes elastic compensating body 150, for improving the compressible of quick 120 interior media of cylinder of sound
Property.In the present embodiment, elastic compensating body 150 can be made of water-fast rubber material, for example, polyurethane material can be used.
Elastic compensating body 150 is set in the cavity 121 of the quick cylinder 120 of sound.For example, can be set in the inner wall or chamber of the quick cylinder 120 of sound
Other positions in body 121.Certainly, it in order to avoid the measurement accuracy that elastic compensating body 150 influences fiber grating 140, should be avoided
Elastic compensating body 150 is contacted with the fiber grating 140 being arranged in cavity 121.Preferably, elastic compensating body 150 invests balance pipe
130 outer wall.For example, being then attached to balance pipe 130 after can solidifying by die perfusion polyurethane material, polyurethane material
Outer wall forms elastic compensating body 150.The thickness for being attached to the elastic compensating body 150 of 130 outer wall of balance pipe, which can according to need, to be set
It sets, such as may be about 1mm.
121 interior media compressibility of cavity is improved by setting elastic compensating body 150, is conducive to improve this fiber grating
The measurement sensitivity of hydrophone 100 enables optical fiber grating sonic device 100 i.e. biggish quiet within the scope of larger water depth ratio
Retention property in range is pressed to stablize.
In order to illustrate the technical solution of the embodiments of the present invention more clearly, below will be with a kind of fiber grating shown in Fig. 4
For hydrophone 100, to the present embodiment provides the working principles of optical fiber grating sonic device 100 and effect to be illustrated.
All in all, the acoustic pressure detection principle of this optical fiber grating sonic device 100 are as follows: the quick cylinder 120 of sound is acted in acoustic pressure to be measured
Under deform, cause the axial tension of fiber grating 140, cause the central wavelength of the reflected light of fiber grating 140 to occur inclined
It moves, that is, underwater sound signal is converted into optical signal.It further, can by the center wavelength variation of detection fiber grating 140
To obtain the size of acoustic pressure to be measured.
In concrete application, this optical fiber grating sonic device 100 under the action of the quasi-static hydraulic pressure of hydrostatic pressing or low frequency variations,
External fluid reaches pressure equilibrium by the fluid in the cavity 121 of intercommunicating pore 111 and balance pipe 130 and the quick cylinder 120 of sound.Work as sound
When the inside and outside pressure equilibrium of quick cylinder 120, extremely small deformation only occurs for the quick cylinder 120 of sound, accordingly results in fiber grating 140
Extremely small axial tension occurs.At this point, the variation of the central wavelength of fiber grating 140 is smaller, i.e., to hydrostatic pressing or low
Frequency acoustic pressure is insensitive, and resistance to hydrostatic pressure ability is strong.
And when under the effect of upper frequency acoustic pressure, by intercommunicating pore 111 and balance pipe 130 to the cavity 121 of the quick cylinder 120 of sound
The acoustic pressure of interior propagation is since there are time delays, so that the pressure equilibrium with external fluid is temporarily not achieved in the fluid in the quick cylinder 120 of sound.
Therefore, there are instantaneous pressure differences for the inner and outer wall of the quick cylinder 120 of sound, cause the quick cylinder 120 of sound that moderate finite deformation occurs.And work as sound
When filling out hydraulically full inside quick cylinder 120, although the compressibility of liquid is smaller, due to the presence of elastic compensating body 150, increase
The compressibility of quick 120 interior media of cylinder of sound.Therefore, the amplitude of deformation of the quick cylinder 120 of sound will not fill out hydraulically full because of inside
And it varies widely.That is, within the scope of biggish static pressure, higher-frequency acoustic pressure can all cause the quick cylinder 120 of sound occur compared with
Big deformation causes the axial tension of fiber grating 140.At this point, the center wavelength variation of fiber grating 140 is larger, acoustic pressure is sensitive
Degree is higher, and hydrophone is sensitive to higher-frequency acoustic pressure.
It is the intercommunicating pore 111 that is sequentially communicated, flat it should be noted that in optical fiber grating sonic device 100 provided in this embodiment
The acoustic cavity structure that the cavity 121 of the weighing apparatus quick cylinder 120 of 130 harmony of pipe is constituted plays the role of low-pass filtering, this fiber grating water
Listen the detectable sound pressure signal lower-frequency limit of device 100 related with the cutoff frequency of the acoustic cavity.The specific structure of the acoustic cavity can
It is designed with the sound pressure signal frequency range for needing to measure according to hydrophone.For example, in order to reduce sound pressure signal lower-frequency limit as far as possible,
Realize that preferable sound pressure signal frequency range, the value range of the internal diameter of balance pipe 130 can be 0.5-1mm, the value of outer diameter
It may range from 2-3mm.
The effect for the optical fiber grating sonic device 100 that embodiment provides in order to better illustrate the present invention.Inventor is according to Fig. 4
100 structure of optical fiber grating sonic device shown constructs limit element artificial module.Fiber grating water provided in this embodiment is listened
The wavelength sensitivity amplitude-frequency characteristic of device 100 is emulated, and simulation result is as shown in Figure 5.Abscissa indicates sound pressure signal in Fig. 5
Frequency, unit Hz, ordinate indicate the sensitivity of hydrophone, unit pm/Pa.As seen from Figure 5, low-frequency sound pressure is believed
Number, hydrophone sensitivity is lower, i.e. alignment staticaccelerator sound pressure signal is insensitive, and for higher-frequency sound pressure signal, hydrophone is sensitive
Degree is higher, for example, sensitivity is about 0.002pm/Pa in 30Hz-2000Hz frequency range, and it is smaller to rise and fall, and amplitude-frequency characteristic is flat.
In conclusion optical fiber grating sonic device 100 provided in an embodiment of the present invention has abandoned air bag, using the quick cylinder 120 of sound
As acoustic pressure sensing element, balance pipe 130 and fiber grating 140 are respectively positioned in the quick cylinder 120 of sound, small in size, structure is simple, not only
It is not damaged to also help protection fiber grating 140 for the miniaturization for being conducive to optical fiber grating sonic device 100.In addition, by successively
The acoustic cavity structure that the cavity 121 of the quick cylinder 120 of intercommunicating pore 111,130 harmony of balance pipe of connection is constituted, can effectively balance
Hydrostatic pressing improves the frequency measurement range of resistance to hydrostatic pressure ability and sound pressure signal.Further, pass through the chamber in the quick cylinder 120 of sound
Elastic compensating body 150 is set in body 121, increases the compressibility of quick 120 interior media of cylinder of sound, improves this fiber grating water
The measurement sensitivity for listening device 100 enables the retention property within the scope of biggish static pressure of optical fiber grating sonic device 100 to stablize.
Second embodiment
As shown in fig. 6, second embodiment of the invention additionally provides a kind of acoustic pressure sensor-based system 10, including light supply apparatus 200,
The optical fiber grating sonic device 100 that demodulating equipment 300 and above-mentioned first embodiment provide.Wherein, optical fiber grating sonic device 100 can
To be one, it is also possible to multiple.As shown in fig. 6, light supply apparatus 200 and demodulating equipment 300 with optical fiber grating sonic device 100
Fiber grating 140 it is optical coupled, wherein arrow is for illustrating optical signal.The detection light that light supply apparatus 200 issues enters optical fiber
Grating 140, the detection light reflected by fiber grating 140 are incident on demodulating equipment as the signal light for carrying sound pressure signal to be measured
300, the demodulated demodulation of device 300 obtains acoustic pressure to be measured.
In the present embodiment, light supply apparatus 200 may include laser or laser diode etc..
In the present embodiment, demodulating equipment 300 may include using Wavelength demodulation module, photodetector and data processing mould
Block.Light supply apparatus 200, optical fiber grating sonic device 100 and photodetector are coupled with Wavelength demodulation modular optical, data processing
Module is coupled with photodetector.The central wavelength for the signal light that Wavelength demodulation module is exported for demodulating fiber bragg grating 140 becomes
Change amount.Photodetector is used to the optical signal that Wavelength demodulation module exports being converted to voltage signal, and the voltage signal is sent out
Give data processing module.Data processing module obtains acoustic pressure to be measured for handling the voltage signal.
In the present embodiment, Wavelength demodulation module may include non-equilibrium interferometer, pass through non-equilibrium interferometer Wavelength demodulation
The central wavelength that the signal light that method exports fiber grating 140 is demodulated to obtain the signal light of the output of fiber grating 140 becomes
Change amount.For example, non-equilibrium interferometer can use optical fiber type Michelson's interferometer or optical fiber type Mach-Zehnder interferometer.
Data processing module can be computer, or may be that single-chip microcontroller, DSP, ARM or FPGA etc. have at data
Manage the chip of function.Data processing module can pass through the preset Wavelength demodulation algorithm or base that carrier wave algorithm is generated based on phase
The center wavelength variation amount of the signal light of the output of fiber grating 140 is obtained in the Wavelength demodulation algorithm process of heterodyne detection, in turn
Acoustic pressure to be measured is measured according to the center wavelength variation.
Certainly, acoustic pressure sensor-based system 10 provided in this embodiment can also include other knots other than above structure
Structure, such as optical isolator, display etc..These other structures are specifically referred to existing acoustic pressure sensor-based system, herein not
It elaborates.
The above description is merely a specific embodiment, but scope of protection of the present invention is not limited thereto, any
Those familiar with the art in the technical scope disclosed by the present invention, can easily think of the change or the replacement, and should all contain
Lid is within protection scope of the present invention.Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. a kind of optical fiber grating sonic device characterized by comprising
Pedestal is equipped with intercommunicating pore;
The first end of the quick cylinder of sound, the quick cylinder of sound is connect with the pedestal, forms a cavity;
Balance pipe is set in the cavity, and the first opening of the balance pipe is connected to the intercommunicating pore, the balance pipe
Second opening is connected to the cavity, so that after external fluid is entered by the intercommunicating pore, through described in balance pipe inflow
Cavity;
Fiber grating is set in the cavity, and the first tail optical fiber of the fiber grating is fixedly connected with the pedestal, the light
Second tail optical fiber of fine grating is fixedly connected with the second end of the quick cylinder of the sound, and the fiber grating exists for measuring the quick cylinder of the sound
The lower axial deformation occurred of sound pressure signal effect to be measured, output carry the signal light of the sound pressure signal to be measured;
Wherein, the quick cylinder of the sound is made of acoustic sensing material, and the quick cylinder of sound deforms under acoustic pressure effect, the quick cylinder of sound
For incuding extraneous sound pressure signal.
2. optical fiber grating sonic device according to claim 1, which is characterized in that further include: for improving the quick cylinder of the sound
The elastic compensating body of the compressibility of interior media, the elastic compensating body are set in the cavity.
3. optical fiber grating sonic device according to claim 2, which is characterized in that the elastic compensating body invests the balance
The outer wall of pipe.
4. optical fiber grating sonic device according to claim 1, which is characterized in that the fiber grating is located at the balance pipe
Interior, the first tail optical fiber of the fiber grating is pierced by first opening and is fixedly connected with the pedestal, and the of the fiber grating
Two tail optical fibers are pierced by second opening and are fixedly connected with the second end of the quick cylinder of the sound.
5. optical fiber grating sonic device according to claim 1, which is characterized in that the intercommunicating pore includes setting along first direction
The first inlet opening set and the second inlet opening being arranged in a second direction, first inlet opening and second inlet opening intersection
And be connected to, the first open communication of second inlet opening and the balance pipe, so that external fluid is intake by described first
After hole enters, the cavity is flowed into through second inlet opening, the balance pipe.
6. optical fiber grating sonic device according to claim 5, which is characterized in that the pedestal is cylindrical structure, described
First direction is the radial direction of the pedestal, and the second direction is the central axis direction of the pedestal.
7. optical fiber grating sonic device according to claim 1, which is characterized in that one end of the pedestal is provided with boss,
The intercommunicating pore is connected to through the boss with the balance pipe, and the first end of the quick cylinder of sound is open end, the quick cylinder of sound
Second end be closed end, the open end is connect with the boss, to form the cavity.
8. optical fiber grating sonic device according to claim 1, which is characterized in that the quick cylinder of sound is cylindrical structure, institute
The axial direction that balance pipe is stated along the quick cylinder of the sound is set in the cavity.
9. optical fiber grating sonic device according to claim 1, which is characterized in that the wall thickness of the quick cylinder of sound is in 0.5-
In the range of 0.8mm.
10. a kind of acoustic pressure sensor-based system, which is characterized in that including light supply apparatus, demodulating equipment and at least one want such as right
Seek optical fiber grating sonic device described in any one of 1-9, the light supply apparatus and the demodulating equipment with the fiber grating
The fiber grating of hydrophone is optical coupled, and the detection light that the light supply apparatus issues enters the fiber grating, by the optical fiber
The detection light of optical grating reflection is incident on the demodulating equipment as the signal light for carrying sound pressure signal to be measured, through the demodulating equipment
Demodulation obtains acoustic pressure to be measured.
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CN110673204B (en) * | 2019-11-13 | 2021-06-11 | 山东省科学院激光研究所 | Fiber grating hydrophone based on balance static pressure of spiral pipe |
CN113405645B (en) * | 2021-06-08 | 2022-09-27 | 哈尔滨工程大学 | Hydrostatic pressure resistant optical fiber hydrophone based on piston |
CN114623918A (en) * | 2022-02-28 | 2022-06-14 | 浙江大学 | Low-pass filtering fiber grating hydrophone adopting tensile coating for sensitization |
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CN101210842A (en) * | 2006-12-31 | 2008-07-02 | 中国科学院半导体研究所 | Static pressure self-compensation optical fibre grating sonic device |
US20110305116A1 (en) * | 2009-08-19 | 2011-12-15 | Nicholas Lagakos | Intensity Modulated Fiber Optic Hydrophones |
CN103344316A (en) * | 2013-07-02 | 2013-10-09 | 山东省科学院激光研究所 | Sound wave sensor probe of asymmetric structure and hydrophone |
CN103492842A (en) * | 2011-04-14 | 2014-01-01 | 泰勒斯公司 | All-optical hydrophone that is not sensitive to temperature or static pressure |
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CN101210842A (en) * | 2006-12-31 | 2008-07-02 | 中国科学院半导体研究所 | Static pressure self-compensation optical fibre grating sonic device |
US20110305116A1 (en) * | 2009-08-19 | 2011-12-15 | Nicholas Lagakos | Intensity Modulated Fiber Optic Hydrophones |
CN103492842A (en) * | 2011-04-14 | 2014-01-01 | 泰勒斯公司 | All-optical hydrophone that is not sensitive to temperature or static pressure |
CN103344316A (en) * | 2013-07-02 | 2013-10-09 | 山东省科学院激光研究所 | Sound wave sensor probe of asymmetric structure and hydrophone |
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