CN103017884A - Cavity body calibrating hydrophone array elements in the air - Google Patents
Cavity body calibrating hydrophone array elements in the air Download PDFInfo
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- CN103017884A CN103017884A CN2012105497346A CN201210549734A CN103017884A CN 103017884 A CN103017884 A CN 103017884A CN 2012105497346 A CN2012105497346 A CN 2012105497346A CN 201210549734 A CN201210549734 A CN 201210549734A CN 103017884 A CN103017884 A CN 103017884A
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Abstract
The invention discloses a cavity body calibrating hydrophone array elements in the air. The cavity body calibrating hydrophone array elements in the air comprises a pressure wave generator, a sound wave transmission channel, an entrant sound subsystem, wherein the pressure wave generator comprises a speaker, a first wave cavity and a sound insulation cavity, the entrant sound subsystem comprises an outer cover and a second wave cavity, the outer cover axially extending to a receiving array channel, the second wave cavity is formed by connecting the sound wave transmission channel and an entrant sound opening, and the hole diameter of the entrant sound opening axially extends to a selected array element. The cavity body calibrating hydrophone array elements in the air has the advantages that: (1) a required sound field is provided for testing of a single array element of a long-line hydrophone array in the air, and simultaneously, by changing drive signals of the speaker, optional drives are provided for single array element during testing; (2) sound insulation designs such as sound insulation boxes and sound insulation materials filling are utilized, accordingly background noise encountered during normal hydrophone array testing can be reduced, and signal-to-noise ratio during testing is improved.
Description
Technical field
The present invention relates to a kind of cavity of calibrating hydrophone array array element, more specifically, it relates to a kind of cavity in air alignment hydrophone array array element.
Background technology
Along with the development of commercial and military domain, the long alignment array that utilizes the low frequency nautical receiving set to form obtains the marine acoustics environmental data and becomes more and more important.Because the length of linear array has rice up to a hundred, according to the free field far field collimation technique requirement of routine, measuring distance is very far away, under laboratory condition, can't calibrate it, if measure in open waters, then not only enforcement is very difficult, and of a high price.Simultaneously, because measuring distance is very large, often be difficult to guarantee all even isotropy of sound field and location fix accurately, add the reduction of signal to noise ratio (S/N ratio), also greatly affected measuring accuracy, can only carry out guestimate to sensitivity and directivity, and can't grasp the performance of linear array with the variation tendency of temperature and pressure.In addition, along with the use of long linear array, in many application scenarios, array also develops into two dimension by one dimension.Receive the analysis ability of information in order to improve pair array array element, need to obtain phase place and the sensitivity information of online array element, and require the phase place of array element and sensitivity to possess reasonable consistance.Therefore, abroad before and after the 1970s and 1980s in last century, in succession developed the method for several linear arrays calibrations: 1) winding method, sensitivity that can the lubber-line array, directivity that can not the lubber-line array; 2) watertight aircase method, the lower frequency limit of calibration is lower, but directivity that equally can't the lubber-line array; 3) manage the alignment method, not only can calibrate the sensitivity of towing line array or array element group, also can calibrate its far field directive property.Simultaneously, the pressure and temperature in all right control tube.But the array installation is very inconvenient during the calibration of pipe alignment device, can only use in the laboratory.In above-mentioned all appraisal procedures and equipment to hydrophone array array element, manyly be not suitable for production facility, some equipment need to carry out in fluid media, and other needs are with reference to nautical receiving set.In test, these characteristics with reference to nautical receiving set array element can change with temperature, use and time, also had other reference to understand can't to eliminate because of nautical receiving set array element densely covered to cause the generation of not wanting signal.In other words, these are used for determining with reference to the equipment that can not provide simple, hold usefulness whether the single array element of hydrophone array accurately installs and on-line performance.In order to satisfy the testing requirement of long line hydrophone array and array element acoustical behavior under outfield or working condition thereof, must solve method of testing or test required sound field condition question.
Summary of the invention
The objective of the invention is to overcome deficiency of the prior art, provide a kind of rational in infrastructure, precision is high, and good stability is at the cavity of air alignment hydrophone array array element.
The objective of the invention is to be achieved through the following technical solutions.This cavity in air alignment hydrophone array array element, comprise pressure wave generator, Acoustic Wave Propagation passage, entrant sound subsystem, wherein pressure wave generator comprises loudspeaker, first wave chamber, sound insulation chamber, wherein the entrant sound subsystem comprises that one extends axially the outer cover that receives the battle array passage and one by connecting the Acoustic Wave Propagation passage and extending axially the aperture and form to formed Second Wave chamber the entrant sound mouth of selecting array element.
As preferably: described Second Wave chamber is for axially being a design of falling the bugle, and the Second Wave chamber has maximum ga(u)ge or width in the excircle direction of outer cover, then reduces to gradually the minimum dimension that can contain hydrophone array.
As preferably: cavity space is combined by first wave chamber, propagation ducts and Second Wave chamber, the loudspeaker that is placed on upper end, first wave chamber by excitation produces pressure wave, make pressure wave pass through the Acoustic Wave Propagation channels spread from the first wave chamber in the Second Wave chamber of the shape of falling the bugle of entrant sound subsystem, finally pressure wave is converged to the bugle smallest end faces the position of tested array element towards the test cavity entrant sound groove place.
As preferably: loudspeaker is installed in the top in first wave chamber, the first wave chamber is positioned at first sound insulation chamber, between first wave chamber and sound insulation chamber, fill sound insulating material, outside first sound insulation chamber, also had second sound insulation chamber, also filled sound insulating material between two sound insulation chambeies.
As preferably: also be provided with sound insulating material between Second Wave chamber and the outer cover.
As preferably: satisfy in the Second Wave chamber strict makes pressure wave generator propagate the sound wave of coming to converge to the axially trapezoidal shape of the narrowest concentric circles annular entrant sound groove of Second Wave chamber.
As preferably: the width of described entrant sound groove is less than the spacing of tested array element.
As preferably: the width of described entrant sound groove is 1/4～1/2 of tested array element distance.
The invention has the beneficial effects as follows: in air, for the single array element of testing long line hydrophone array provides required sound field, simultaneously, by changing the pumping signal of loudspeaker, can when test, provide optional excitation for single array element.Utilize the sound insulation designs such as sound insulation chamber and filling sound insulating material, can reduce the ground unrest that runs in the test of normal hydrophone array, the signal to noise ratio (S/N ratio) when having improved test.The width of entrant sound groove is less than the array element distance of tested hydrophone array, approximately is 1/4～1/2 of array element distance, does not survey array element to guarantee that pressure wave only acts on not have influence on the tested array element.The design of annular entrant sound groove is in order to guarantee that pressure wave is applied on the tested array element accurately, and supporting construction is in order to guarantee the axial level of tested segment.Simultaneously, isolated sound wave blazes abroad from test chamber and has affected other array element.
The design of whole test cavity utilizes that loudspeaker can satisfy the low frequency operation requirement better in the aeroacoustics.Simultaneously, utilize the remittance sound effect of Acoustic Wave Propagation in the aeroacoustics and bugle structure thereof, for the test of the single array element of long line hydrophone array provides needed sound field.By the design of sound insulating material and structure, reduced the impact of ground unrest on tested array element, improved signal to noise ratio (S/N ratio).Utilize the cavity of this design, only need common audio-frequency generator and testing apparatus just can form test macro, satisfy the on-the-spot test that hydrophone array is listed in lab investigation, production test and outfield.In addition, utilize the performance that the cavity of this design and corresponding method also can the measurement hydrophone array.
Description of drawings
Fig. 1 is structural representation of the present invention;
Fig. 2 is entrant sound subsystem schematic diagram;
Fig. 3 is the A-A cut-open view of Fig. 2;
Reference numeral: pressure wave generator 1, sound insulation chamber 2, Acoustic Wave Propagation passage 3, entrant sound subsystem 4, loudspeaker 5, first wave chamber 6, sound insulating material 7, tested array element 8, Second Wave chamber 9, test cavity 10, outer cover 11, entrant sound groove 12, hydrophone array 13.
Embodiment
Below in conjunction with drawings and Examples the present invention is described further.Although the present invention is described in connection with preferred embodiment, should know, do not represent to limit the invention among the described embodiment.On the contrary, the present invention will be contained alternative, modified and the equivalent in the scope of the present invention that can be included in attached claims restriction.
The design concept of cavity: the control to sound wave is realized in the sound wave that sends with loudspeaker 5 utilizes the combination of different cavitys to change sound wave when propagating in air route of transmission, obtains testing the required sound field of hydrophone array array element performance by guide sound wave propagation approach and size.Utilize this cavity, the phase and magnitude by control loudspeaker 5 pumping signals provides optional sound field for the test of array element; Utilize the sound insulation chamber 7 of cavity to design, select the test cavity of sound insulating material filling and particular design can also reduce the ground unrest that runs in the normal nautical receiving set test, improve the signal to noise ratio (S/N ratio) of test.Therefore, the sound field of utilizing this cavity to produce can realize the test to hydrophone array array element acoustic performance in air, satisfy the long linear array array element of low frequency in the laboratory, outfield or production line realization be to the test of array element acoustic performance.In addition, utilize this cavity, by the next test that can realize whole array performance of specific method.
Whole cavity comprises that a pressure wave generator 1, Acoustic Wave Propagation passage 3 and one can form the pressure wave direct effect to the entrant sound subsystem 4 on the chosen tested nautical receiving set array element.(as shown in Figure 1).Pressure wave generator 1 arrives entrant sound subsystem 4 to the pressure-wave emission that produces by Acoustic Wave Propagation passage 3, and entrant sound subsystem 4 utilizes the test cavitys that chosen tested array element 8 fully is in the encirclement of required pressure wave sound field.
Needed pressure wave occurs in pressure wave generator 1; Sound insulation chamber 2, the sound wave of isolated pressure wave generator 1 leaks; Acoustic Wave Propagation passage 3 is sent to entrant sound subsystem 4 to the sound wave that produces in the pressure wave generation cavity; Entrant sound subsystem 4 is propagated pressure wave generator 1 pressure wave of coming by falling after the effect of converging of bugle direct effect on the tested array element 8 of chosen hydrophone array.In Fig. 1, pressure wave generator 1 comprises a loudspeaker 5 that is driven by low-frequency sine, first wave chamber 6, and sound insulation chamber 2 and sound wave propagation ducts 3 form.Loudspeaker 5 is installed in the top in first wave chamber 6, first wave chamber 6 is positioned at first sound insulation chamber 2, between first wave chamber 6 and sound insulation chamber 2, filled sound insulating material 7, outside first sound insulation chamber 2, also had between 2, two cavitys in second sound insulation chamber and also filled sound insulating material 7.Utilize two sound insulation chambeies 2 can completely cut off the sound wave diffusion that pressure wave generator 1 produces fully, also can completely cut off extraneous sound field to the impact of acoustic wavefield in the pressure wave chamber.Simultaneously, also avoided loudspeaker 5 front-end and back-end to leak sound wave to the impact of tested hydrophone array 13.
From Fig. 1, Fig. 2 and Fig. 3, can find out, entrant sound subsystem 4 has 9, one outward directions in Second Wave chamber of the annular of an axial passage that includes certain pore size to fill the circular cylindrical cavity of sound insulating material 7, cingens, the axially extended Second Wave of annular chamber 9 and test cavity 10.Second Wave chamber 9 axially is being a design of falling the bugle, and bugle has maximum ga(u)ge or width in the excircle direction of circular cylindrical cavity, then reduces to gradually the minimum dimension that can contain tested long alignment.As shown in Fig. 1 and Fig. 2, strict trapezoidal shape is satisfied in the Second Wave chamber 9 of entrant sound subsystem 4.This feature can make from pressure wave generator 1 and propagate the axially entrant sound groove 12 of the narrowest concentric circles annular of Second Wave chamber 9 that the sound wave of coming converges to entrant sound subsystem 4.The width of entrant sound groove 12 is less than tested array element 8 spacings of tested hydrophone array, approximately is 1/4～1/2 of tested array element 8 spacings.Do not survey array element with regard to having guaranteed that pressure wave only acts on not have influence on the tested array element 8 like this.The test cavity of entrant sound subsystem 4 comprises entrant sound groove 12 and supports the structure of tested hydrophone array tested segment.The design of annular entrant sound groove 12 is in order to guarantee that pressure wave is applied on the tested array element 8 accurately, and outer cover 11 is in order to guarantee the axial level of tested segment.Simultaneously, isolated sound wave blazes abroad from test cavity 10 has affected other array element.
In Fig. 1, the Acoustic Wave Propagation passage 3 that connects between first wave chamber 6 and the Second Wave chamber 9 has guaranteed that pressure wave produces focussing force on the tested array element 8 of tested hydrophone array.Also be to be wrapped in sound insulating material 7 outside the Acoustic Wave Propagation passage 3, guarantee sound wave the least possible leaking in propagating the way.
Claims (8)
1. cavity in air alignment hydrophone array array element, it is characterized in that: comprise pressure wave generator (1), Acoustic Wave Propagation passage (3) and entrant sound subsystem (4), wherein pressure wave generator (1) comprises loudspeaker (5), first wave chamber (6) and sound insulation chamber (2), wherein entrant sound subsystem (4) comprises that one extends axially the outer cover (11) that receives the battle array passage and one by connecting Acoustic Wave Propagation passage (3) and extending axially the aperture to formed Second Wave chamber (9) the entrant sound mouth of selecting array element.
2. the cavity in air alignment hydrophone array array element according to claim 1, it is characterized in that: described Second Wave chamber (9) is for axially being a design of falling the bugle, Second Wave chamber (9) has maximum ga(u)ge or width in the excircle direction of outer cover (11), then reduces to gradually the minimum dimension that can contain hydrophone array (13).
3. the cavity in air alignment hydrophone array array element according to claim 1, it is characterized in that: cavity space is by first wave chamber (6), propagation ducts (3) and Second Wave chamber (9) combine, the loudspeaker (5) that is placed on upper end, first wave chamber (6) by excitation produces pressure wave, pressure wave is propagated into by Acoustic Wave Propagation passage (3) from first wave chamber (6) in the Second Wave chamber (9) of the shape of falling the bugle of entrant sound subsystem (4), finally pressure wave is converged to the bugle smallest end and locate towards the entrant sound groove (12) that test cavity (10) faces the position of tested array element (8).
4. the cavity in air alignment hydrophone array array element according to claim 1, it is characterized in that: loudspeaker (5) is installed in the top of first wave chamber (6), first wave chamber (6) is positioned at first sound insulation chamber (2), between first wave chamber (6) and sound insulation chamber (2), filled sound insulating material (7), outside first sound insulation chamber (2), also have second sound insulation chamber (2), filled sound insulating material (7) between two sound insulation chambeies (2).
5. the cavity in air alignment hydrophone array array element according to claim 1 is characterized in that: be provided with sound insulating material (7) between Second Wave chamber (9) and the outer cover (11).
6. the cavity in air alignment hydrophone array array element according to claim 1 is characterized in that: satisfy Second Wave chamber (9) strict makes pressure wave generator (1) propagate the sound wave of coming to converge to the axially trapezoidal shape of the narrowest concentric circles annular entrant sound groove (12) of Second Wave chamber (9).
7. according to claim 2 or 6 described cavitys in air alignment hydrophone array array element, it is characterized in that: the width of described entrant sound groove (12) is less than the spacing of tested array element (8).
8. according to claim 2 or 6 described cavitys in air alignment hydrophone array array element, it is characterized in that: the width of described entrant sound groove (12) is 1/4～1/2 of tested array element (8) spacing.
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Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104198593A (en) * | 2014-08-26 | 2014-12-10 | 中国船舶重工集团公司第七一五研究所 | High-hydrostatic-pressure low-frequency calibrating cavity and testing method thereof |
| CN104237870A (en) * | 2014-08-21 | 2014-12-24 | 中国船舶重工集团公司第七一五研究所 | Device and method for testing low-frequency linear array acoustic performance in air |
| CN104237870B (en) * | 2014-08-21 | 2017-01-04 | 中国船舶重工集团公司第七一五研究所 | The device of a kind of low frequency wire array acoustical behavior of test in atmosphere and method of testing |
| CN107102060A (en) * | 2017-04-26 | 2017-08-29 | 北京理工大学 | A kind of two-dimensional underwater sound Free field measurement method based on acoustic pressure compensation mechanism |
| CN105444874B (en) * | 2015-11-10 | 2018-10-26 | 株洲时代新材料科技股份有限公司 | A kind of sound intersity measurement calibrating installation and method |
| CN109413560A (en) * | 2018-08-30 | 2019-03-01 | 南京粒子声学科技有限公司 | A kind of device for realizing vector sensor calibration using matching layer |
| CN109443515A (en) * | 2018-09-13 | 2019-03-08 | 中国船舶重工集团公司第七〇五研究所 | Test macro and method in a kind of small size hydrophone sensitivity air |
| CN109764950A (en) * | 2019-01-28 | 2019-05-17 | 中国船舶重工集团公司第七一五研究所 | A kind of synchronous vibration type vector hydrophone absolute Calibrating Method based on accelerometer |
| CN111289095A (en) * | 2020-02-24 | 2020-06-16 | 南京俏声波动科技有限公司 | Sine pressure wave standard source for sensor calibration and working method thereof |
| CN112556817A (en) * | 2020-12-04 | 2021-03-26 | 中国船舶重工集团有限公司第七一0研究所 | System and method for detecting amplitude consistency of low-frequency acoustic array elements in air |
| CN112630757A (en) * | 2020-11-30 | 2021-04-09 | 海鹰企业集团有限责任公司 | Hydrophone array element consistency rapid detection device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4205394A (en) * | 1978-11-03 | 1980-05-27 | The United States Of America As Represented By The Secretary Of The Navy | Sealed cavity hydrophone array calibration |
| CN102322935A (en) * | 2011-08-22 | 2012-01-18 | 江苏大学 | Flowing noise measuring device |
| CN202133462U (en) * | 2011-05-17 | 2012-02-01 | 哈尔滨工程大学 | Real-time calibrating device suitable for coseismic vector hydrophone |
-
2012
- 2012-12-17 CN CN201210549734.6A patent/CN103017884B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4205394A (en) * | 1978-11-03 | 1980-05-27 | The United States Of America As Represented By The Secretary Of The Navy | Sealed cavity hydrophone array calibration |
| CN202133462U (en) * | 2011-05-17 | 2012-02-01 | 哈尔滨工程大学 | Real-time calibrating device suitable for coseismic vector hydrophone |
| CN102322935A (en) * | 2011-08-22 | 2012-01-18 | 江苏大学 | Flowing noise measuring device |
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104237870A (en) * | 2014-08-21 | 2014-12-24 | 中国船舶重工集团公司第七一五研究所 | Device and method for testing low-frequency linear array acoustic performance in air |
| CN104237870B (en) * | 2014-08-21 | 2017-01-04 | 中国船舶重工集团公司第七一五研究所 | The device of a kind of low frequency wire array acoustical behavior of test in atmosphere and method of testing |
| CN104198593B (en) * | 2014-08-26 | 2016-06-29 | 中国船舶重工集团公司第七一五研究所 | A kind of high hydrostatic pressure low-frequency calibration cavity and method of testing |
| CN104198593A (en) * | 2014-08-26 | 2014-12-10 | 中国船舶重工集团公司第七一五研究所 | High-hydrostatic-pressure low-frequency calibrating cavity and testing method thereof |
| CN105444874B (en) * | 2015-11-10 | 2018-10-26 | 株洲时代新材料科技股份有限公司 | A kind of sound intersity measurement calibrating installation and method |
| CN107102060A (en) * | 2017-04-26 | 2017-08-29 | 北京理工大学 | A kind of two-dimensional underwater sound Free field measurement method based on acoustic pressure compensation mechanism |
| CN107102060B (en) * | 2017-04-26 | 2019-09-10 | 北京理工大学 | A kind of two-dimensional underwater sound Free field measurement method based on acoustic pressure compensation mechanism |
| CN109413560A (en) * | 2018-08-30 | 2019-03-01 | 南京粒子声学科技有限公司 | A kind of device for realizing vector sensor calibration using matching layer |
| CN109443515B (en) * | 2018-09-13 | 2021-05-14 | 中国船舶重工集团公司第七一五研究所 | System and method for testing sensitivity of small-size hydrophone in air |
| CN109443515A (en) * | 2018-09-13 | 2019-03-08 | 中国船舶重工集团公司第七〇五研究所 | Test macro and method in a kind of small size hydrophone sensitivity air |
| CN109764950A (en) * | 2019-01-28 | 2019-05-17 | 中国船舶重工集团公司第七一五研究所 | A kind of synchronous vibration type vector hydrophone absolute Calibrating Method based on accelerometer |
| CN111289095A (en) * | 2020-02-24 | 2020-06-16 | 南京俏声波动科技有限公司 | Sine pressure wave standard source for sensor calibration and working method thereof |
| CN111289095B (en) * | 2020-02-24 | 2023-11-03 | 南京俏声波动科技有限公司 | Sinusoidal pressure wave standard source for sensor calibration and working method thereof |
| CN112630757A (en) * | 2020-11-30 | 2021-04-09 | 海鹰企业集团有限责任公司 | Hydrophone array element consistency rapid detection device |
| CN112630757B (en) * | 2020-11-30 | 2024-04-19 | 海鹰企业集团有限责任公司 | Hydrophone array element uniformity rapid detection device |
| CN112556817A (en) * | 2020-12-04 | 2021-03-26 | 中国船舶重工集团有限公司第七一0研究所 | System and method for detecting amplitude consistency of low-frequency acoustic array elements in air |
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