CN118075668A - Microphone array capable of inhibiting edge diffraction effect and design method thereof - Google Patents
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Abstract
The invention belongs to the technical field of aerodynamic noise wind tunnel test, and discloses a microphone array capable of inhibiting edge diffraction effect and a design method thereof, wherein the microphone array comprises an array body which is formed by splicing an array panel and a back shell and is provided with an inner cavity; the edge of the array body is provided with a plurality of cantilevers which are spirally distributed on the plane of the array body; the microphones are arranged along the axial direction of the cantilever, and a plurality of micropores are formed in the edge of the array panel and access to the inner cavity of the array body. The micro holes arranged on the surface of the array panel and the inner cavity of the array body are used for absorbing sound waves, so that a new secondary wave source is prevented from being formed due to diffraction phenomenon when the sound waves meet the cantilever, and the influence of the new secondary wave source on a test result is eliminated.
Description
Technical Field
The invention belongs to the technical field of aerodynamic noise wind tunnel tests, and particularly relates to a microphone array capable of inhibiting an edge diffraction effect and a design method thereof.
Background
The magnetic levitation flight wind tunnel is a new concept aerodynamic test facility combining a vacuum pipeline high-speed magnetic levitation technology with a dynamic model test principle, can form a 'body dynamic wind static' test environment which is close to a real flight state, has the characteristics of rapid acceleration/deceleration, variable density and the like, has natural advantages in researching low noise, low Reynolds number and dynamic aerodynamic problems, can be used for researching aerodynamic problems in the aerodynamic noise, high-altitude flight performance and rapid maneuvering process of an aircraft, and solving the problems of noise reduction, dynamics evaluation and the like of a high-speed drag reduction train, and powerfully supports innovative development of an aerospace aircraft and high-speed traffic equipment. The magnetic levitation flight wind tunnel test section consists of a closed pipeline and a floor. The wall surface of the pipeline has a silencing function, and can eliminate sound wave reflection generated by the motion model. Therefore, the method is suitable for developing aerodynamic noise test evaluation, noise generation mechanism and noise reduction technology research of motion models such as aircrafts, high-speed trains and the like in the magnetic levitation flight wind tunnel.
The positioning and evaluation of aerodynamic noise sources are carried out in wind tunnels and are mainly realized by means of microphone arrays. The microphone array is composed of an array panel, microphones, cables, a bracket and the like, wherein the microphones are arranged on the array panel in a certain regular manner, and the microphones receive sound waves emitted from the sound source position. Due to the existence of the sound path difference, the sound waves received by the microphone have a phase difference. Generating a scanning surface at the potential sound source position in the test model area, reconstructing a sound field by using a sound wave propagation model, and superposing sound waves measured by all microphones (delay summation), so that the sound source can be positioned. After the sound source position is obtained, the sound power of the specific sound source area is integrated, and then the magnitude of the sound source can be estimated. The sound source localization and evaluation plays an important role in low-noise selection, noise reduction technology research and the like of aerospace vehicles and high-speed traffic equipment.
The microphone array is optimally designed, so that the accuracy and the accuracy of sound source positioning and evaluation can be remarkably improved. The array optimization design mainly comprises microphone installation position optimization, array panel optimization and the like. A great deal of research work has been carried out at home and abroad on microphone mounting position optimization, for example, in order to avoid the spatial aliasing effect generated by periodic sampling, and to improve the dynamic range and reduce the sidelobe level as objective functions, underbrink et al propose a multi-arm spiral array design, and have been widely used. According to the acoustic principle, the acoustic wave can generate diffraction, reflection, nonlinear distortion and other effects in the propagation process. When the sound wave encounters an obstacle, a diffraction effect is generated, and a new secondary wave source is formed at the edge of the obstacle, so that the local sound field is amplified. In particular, sound waves will produce a pronounced diffraction effect at the edges of the microphone array panel.
In view of this, there is a need for a microphone array capable of suppressing the edge diffraction effect.
Disclosure of Invention
The invention aims to provide a microphone array capable of inhibiting an edge diffraction effect and a design method thereof, which can solve or relieve the problems to a certain extent, thereby effectively inhibiting the influence of sound wave diffraction at the edge of the microphone array on test measurement and further improving the accuracy and the accuracy of sound source positioning and evaluation.
In order to solve the technical problems, the invention adopts the following technical scheme: a microphone array capable of inhibiting edge diffraction effect comprises an array body which is formed by splicing an array panel and a back shell and is provided with an inner cavity; the edge of the array body is provided with a plurality of cantilevers which are spirally distributed on the plane of the array body; the microphones are arranged along the axial direction of the cantilever, and a plurality of micropores are formed in the edge of the array panel and access to the inner cavity of the array body.
As an improvement, the number of the cantilevers is more than five, and the number of microphones arranged on the cantilevers is more than six; the radian of each cantilever is consistent, and the microphones corresponding to the positions on all the cantilevers are on the same circumference taking the center of the array body as the center of a circle.
As an improvement, the micropores are more than three rows distributed along the edge of the array body.
As an improvement, the microphone mounting device also comprises a mounting seat for mounting the microphone; the mounting seat is annular and is coaxially fixed with the mounting holes on the array panel; the microphone sleeved with the rubber tube extends into the inner hole of the mounting seat and the mounting hole on the array panel and is fixed by the bolt.
As an improvement, the array body is fixed on the tripod, and a lifting rocker arm is arranged between the array body and the tripod. The lifting rocker arm comprises a pitching adjusting mechanism for adjusting a pitching angle and a horizontal adjusting mechanism for adjusting a horizontal angle.
As an improvement, the array panel and the back shell are made of lightweight materials with high acoustic impedance.
As an improvement, the diameter of the array panel is 190 mm-510 mm; the thickness of the array panel is 4.9 mm-5.1 mm; the diameter of the micropores is 0.9 mm-1.1 mm; the hole distance between the micropores is 3.8 mm-4.2 mm; the depth of the cavity is 48 mm-52 mm.
As an improvement, the outermost microphone on the cantilever is on a circumference with the center of the array body as the center and the diameter of 450mm, and the innermost microphone on the cantilever is on a circumference with the center of the array body as the center and the diameter of 300 mm.
The invention also provides a microphone array design method, which is used for obtaining the key design parameters of the microphone array capable of inhibiting the edge diffraction effect; the microphone array parameters comprise the thickness of an array panel, the aperture of micropores, the hole distance between the micropores and the depth of an inner cavity; the design method specifically comprises the following steps:
placing the microphone array in front of a wind tunnel test model to acquire the frequency spectrum characteristics of an aerodynamic noise source;
And in the frequency band range in which the pneumatic noise source energy distribution is concentrated, the maximum sound absorption coefficient is used as an objective function, and the optimal parameters are obtained through an optimization algorithm.
As an improvement, the objective function is:
；
，
，
，
；
Wherein alpha is the sound absorption coefficient; θ is the angle between the normal direction of the micropore and the incidence direction of the sound wave; k r,km is the acoustic resistivity constant and acoustic mass constant, respectively; ω=2pi f is the angular frequency of the sound wave, f is the frequency of the sound wave; c 0 = 340m/s is the speed of sound in air under standard conditions; μ=1.48× -5m2/s is the kinematic viscosity coefficient of air; phi is the perforation rate, which is the ratio of the perforation area to the total area; for round holes arranged in square, the perforation rate ; L is the thickness of the array panel; d is the pore diameter of the micropore; b is the pitch of the micropores; h is the depth of the inner cavity; rs is the ratio of acoustic resistivity; m is the acoustic mass; k is the puncture constant.
As an improvement, the optimization algorithm is one of a particle swarm algorithm or an ant swarm algorithm.
The invention has the advantages that: the microphone array provided by the invention comprises an array body with a sealed inner cavity; the edge of the array body is provided with a plurality of cantilevers which are spirally distributed on the plane of the array body; the microphones are arranged along the axial direction of the cantilever, and a plurality of micropores are formed in the edge of the array panel, and the micropores access the inner cavity of the array body, so that the micropores and the inner cavity cooperate to form a 'filter' for absorbing sound waves. The micro holes arranged on the surface of the array panel and the inner cavity of the array body are used for absorbing sound waves, so that the phenomenon that the sound waves generate diffraction when encountering a cantilever to form a new secondary wave source is avoided, and the influence of the new secondary wave source on a test result is eliminated.
In order to facilitate the installation of the microphone, the microphone mounting seat comprises the mounting seat, and the microphone is fastened by using fasteners such as bolts after being installed in the inner hole of the annular mounting seat, so that the microphone is very convenient and quick to assemble and disassemble.
In order to facilitate the adjustment of the height, the pitching angle and the horizontal angle, the array body is fixed on the tripod, and a lifting rocker arm is arranged between the array body and the tripod. The lifting rocker arm comprises a pitching adjusting mechanism for adjusting a pitching angle and a horizontal adjusting mechanism for adjusting a horizontal angle.
In order to obtain the best effect, the invention also provides a method for obtaining the best parameters of the microphone array capable of inhibiting the edge diffraction, wherein the microphone array parameters comprise the thickness of an array panel, the aperture of micropores, the hole distance among the micropores and the depth of an inner cavity, and the above description uses the maximum sound absorption coefficient as an objective function to obtain the best parameters through an optimization algorithm.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. Like elements or portions are generally identified by like reference numerals throughout the several figures. In the drawings, elements or portions thereof are not necessarily drawn to scale. It will be apparent to those of ordinary skill in the art that the drawings in the following description are of some embodiments of the invention and that other drawings may be derived from these drawings without inventive faculty.
Fig. 1 is a schematic view of a microphone array according to an exemplary embodiment of the present invention;
fig. 2 is a schematic diagram of a backside structure of a microphone array according to an exemplary embodiment of the invention;
FIG. 3 is an enlarged partial view of the cantilever end of an array panel in a microphone array in accordance with an exemplary embodiment of the invention;
fig. 4 is a schematic structural view of a mount in a microphone array according to an exemplary embodiment of the present invention.
FIG. 5 is an enlarged view of a portion of a cantilever-mounted microphone on an array panel after mounting the microphone;
Fig. 6 is a schematic structural view of the back shell.
The marks in the figure: 1 array panel, 2 back shell, 3 cantilevers, 4 microphones, 5 micropore, 6 lifting rocker arms, 7 tripods, 8 mounting holes, 9 screw holes, 10 connecting holes I, 11 mounting seats, 12 bolts, 21 bracket mounting holes, 22 wire passing holes, 23 connecting holes II, 61 pitching adjusting mechanisms and 62 horizontal adjusting mechanisms.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In this document, suffixes such as "module", "component", or "unit" used to represent elements are used only for facilitating the description of the present invention, and have no particular meaning in themselves. Thus, "module," "component," or "unit" may be used in combination.
The terms "upper," "lower," "inner," "outer," "front," "rear," "one end," "the other end," and the like herein refer to an orientation or positional relationship based on that shown in the drawings, merely for convenience of description and to simplify the description, and do not denote or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
The terms "mounted," "configured to," "connected," and the like, herein, are to be construed broadly as, for example, "connected," whether fixedly, detachably, or integrally connected, unless otherwise specifically defined and limited; the two components can be mechanically connected, can be directly connected or can be indirectly connected through an intermediate medium, and can be communicated with each other. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
Herein, "and/or" includes any and all combinations of one or more of the associated listed items.
Herein, "plurality" means two or more, i.e., it includes two, three, four, five, etc.
Prior art chinese patent application No. cn201010171963.X discloses a face spiral microphone array comprising: the array camera is arranged at the center position, the array main body and the microphones are arranged on the array main body, and the array main body is a plurality of plane spiral rigid spokes.
In the prior art, the array main body and the spokes are solid. When the sound wave encounters the spoke, diffraction effect is generated, and a new secondary wave source is formed at the edge of the spoke, so that a local sound field is amplified, and the test result is influenced. In the pneumatic noise wind tunnel test process, the microphone array provided by the invention can effectively improve the accuracy and the precision of noise source positioning and evaluation.
Example 1: as shown in fig. 1 and 2, the invention provides a microphone array capable of inhibiting edge diffraction effect, which comprises an array body formed by splicing an array panel 1 and a back shell 2, wherein the array panel 1 and the back shell 2 penetrate through a connecting hole I10 on the array panel 1 and a connecting hole II23 on the back shell through bolts for connection and fixation; the edge of the array body is provided with a plurality of cantilevers 3 which are spirally arranged on the plane of the array body; the microphones 4 are arranged along the axial direction of the cantilever 3, and a plurality of micropores 5 are formed in the edge of the array panel, and the micropores 5 access the inner cavity of the array body.
The principle of the invention is as follows: the micro holes 5 arranged on the surface of the array panel and the inner cavity of the array body are used for absorbing sound waves, so that the phenomenon that the sound waves generate diffraction when encountering the cantilever 3 is avoided to form a new secondary wave source, and the influence of the new secondary wave source on a test result is eliminated.
In the present invention, the cantilever 3 may be considered as a part of the array body, and thus the above-described "edge of the array panel" also includes the edge of the cantilever 3. The number of the cantilevers 3 is more than 5, in this embodiment, 5 cantilevers 3, and the number of the microphones 4 mounted on each cantilever 3 is more than 6. Specifically, on the premise that the diameter of the array panel is 190 mm-510 mm (more specifically, the diameter of the array panel is 500 mm), 5 cantilevers 3 are spirally and divergently arranged along the same direction, and 6 microphones 4 are arranged on each cantilever 3; furthermore, 1 microphone is arranged in the center of the array.
The radian of each cantilever 3 is consistent, and the microphones corresponding to the positions on all the cantilevers 3 are on the same circumference taking the center of the array body as the center of a circle. For example, the outermost 5 microphones 4 of the 5 cantilevers 3 are on a circumference having a diameter of 450mm, and the innermost 5 microphones 4 are on a circumference having a diameter of 300 mm.
In the present invention, in order to improve the efficiency of absorbing sound waves, the thickness of the array panel 1, the aperture of the micro holes 5, the pitch between the micro holes 5, and the depth of the inner cavity are the most critical parameters. In the invention, on the premise that the diameter of the array panel 1 is 190 mm-510 mm, the thickness of the array panel 1 is 4.9 mm-5.1 mm; the diameter of the micropores is 0.9 mm-1.1 mm; the hole distance between the micropores is 3.8 mm-4.2 mm; the depth of the cavity is 48 mm-52 mm. In addition, the micropores 5 are preferably more than 3 rows arranged along the edge of the array body.
In order to achieve better sound absorption effect, the array panel 1 and the back shell 2 are made of light materials with high sound resistance, for example, the array panel 1 can be made of carbon fiber plates with the thickness of 5mm by laser cutting, and the back shell 2 can be made of ABS plastic materials by 3D printing.
In this embodiment, the microphone 4 is preferably a free sound field microphone having an outer diameter of 1/2 inch and a flat response curve in a frequency band range of 20kHz or less.
As shown in fig. 3, 4 and 5, in order to facilitate the installation of the microphone 4, the present embodiment further includes a mounting seat 11 for mounting the microphone 4; the mounting seat 11 can be made of aluminum alloy, is annular in shape and is coaxially fixed with the mounting hole 8 on the array panel 1; the inner hole diameter of the mounting seat 11 is 7mm, and the microphone 4 sleeved with the rubber tube with the outer diameter of 6mm extends into the inner hole of the mounting seat 11 and the mounting hole 8 on the array panel 1 and is fixed by the bolts 12. More specifically, the mounting seat 11 further comprises a chassis, and can be fixed with the screw hole 9 on the array panel 1 through bolts.
In order to support the array body and adjust the horizontal and pitching angles, the array body is fixed on a tripod 7, and a lifting rocker arm 6 is arranged between the array body and the tripod 7. The lift rocker arm 6 includes a pitch adjustment mechanism 61 for performing pitch angle adjustment, and a horizontal adjustment mechanism 62 for performing horizontal angle adjustment. Through the mechanism, the array body has a height adjusting range (1.2 m-1.5 m) of 0mm-300mm and a horizontal angle adjusting range of-45 degrees. In addition, the column of bodies is required to be perpendicular to the ground when in use, and thus can be adjusted by the pitch adjustment mechanism 61.
As shown in fig. 6, the back shell 2 is provided with a bracket mounting hole 21 for connecting with the lifting rocker arm 6, and a wire passing hole 22 for threading so as to facilitate the arrangement of the wire harness.
When the microphone is assembled, firstly, a rubber tube is arranged on the microphone 4 with the size of 1/4 inch, the microphone 4 sequentially passes through the mounting seat 11 and the mounting hole 8 on the array panel 1, and then the microphone 4 is fixedly locked by the bolts 12. The signal and power supply cables of the microphone 4 are fixed by adopting RG174 cables with 50 ohms according to a group of 6 wires, and the two ends of the cables are respectively stuck with marks; the array panel 1 and the back shell 2 are fixed together through bolts; passing the microphone 4 cable set through the wire through hole 22 of the back shell 2; the array body is fixedly arranged on the tripod 7 through bolts, and the position of the array surface is adjusted through the level gauge so as to be vertical to the ground.
Example 2: the invention also provides a microphone array design method, which is used for obtaining the key design parameters of the microphone array capable of inhibiting the edge diffraction effect; the key design parameters comprise the thickness of the array panel, the aperture of the micropores, the hole distance between the micropores and the depth of the inner cavity; the above parameters have a critical effect on suppressing the edge diffraction effect of the microphone array, and thus, attention needs to be paid to the above parameters in design.
The microphone array design method specifically comprises the following steps:
S1, placing a sound field microphone array described in the embodiment 1 in front of a wind tunnel test model, and acquiring the frequency spectrum characteristics of an aerodynamic noise source.
After time domain data are acquired through primary test, the frequency spectrum characteristics of the pneumatic noise source of the train model are acquired through FFT conversion, and the obtained sound energy is mainly concentrated in the range of 500 Hz-4000 Hz.
S2, in the frequency band range of the pneumatic noise source energy distribution set, the maximum sound absorption coefficient is used as an objective function, and the optimal parameters are obtained through an optimization algorithm.
Specifically, the objective function is:
；
，
，
，
；
Wherein alpha is the sound absorption coefficient; θ is the angle between the normal direction of the micropore and the incidence direction of the sound wave; k r,km is the acoustic resistivity constant and acoustic mass constant, respectively; ω=2pi f is the angular frequency of the sound wave, f is the sound wave frequency; c 0 = 340m/s is the speed of sound in air under standard conditions; μ=1.48× -5m2/s is the kinematic viscosity coefficient of air; phi is the perforation rate, which is the ratio of the perforation area to the total area; for round holes arranged in square, the perforation rate ; L is the thickness of the array panel; d is the pore diameter of the micropore; b is the pitch of the micropores; h is the depth of the inner cavity; rs is the ratio of acoustic resistivity; m is the acoustic mass; k is the puncture constant.
In this embodiment, the optimized solution of the thickness of the array panel, the aperture of the micropores, the pitch between the micropores and the depth of the inner cavity can be obtained by using the optimization algorithm such as the particle swarm algorithm or the ant swarm algorithm to maximize the sound absorption coefficient as the objective function: the thickness of the array panel is 4.9 mm-5.1 mm; the diameter of the micropores is 0.9 mm-1.1 mm; the hole distance between the micropores is 3.8 mm-4.2 mm; the depth of the cavity is 48 mm-52 mm.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present invention and the scope of the claims, which are to be protected by the present invention.
Claims (10)
1. A microphone array capable of suppressing edge diffraction effects, characterized by: comprises an array body which is formed by splicing an array panel and a back shell and is provided with an inner cavity; the edge of the array body is provided with a plurality of cantilevers which are spirally distributed on the plane of the array body; the microphones are distributed along the extending direction of the cantilever, a plurality of micropores are formed in the edge of the array panel, and the micropores access the inner cavity of the array body.
2. A microphone array capable of suppressing edge diffraction effects as recited in claim 1, wherein: the number of the cantilevers is more than five, and more than six microphones are arranged on the cantilevers; the radian of all cantilevers is consistent, and all microphones corresponding to the positions on all cantilevers are on the same circumference taking the center of the array body as the center of a circle.
3. A microphone array capable of suppressing edge diffraction effects as recited in claim 1, wherein: the micropores are distributed along the edges of the array body in more than three rows.
4. A microphone array capable of suppressing edge diffraction effects as recited in claim 1, wherein: the microphone also comprises a mounting seat for mounting the microphone; the mounting seat is annular and is coaxially fixed with the mounting hole on the array panel; the microphone sleeved with the rubber tube extends into the inner hole of the mounting seat and the mounting hole on the array panel and is fixed by the fastener.
5. A microphone array capable of suppressing edge diffraction effects as recited in claim 1, wherein: the array body is fixed on a tripod, and a lifting rocker arm is arranged between the array body and the tripod; the lifting rocker arm comprises a pitching adjusting mechanism for adjusting a pitching angle and a horizontal adjusting mechanism for adjusting a horizontal angle.
6. A microphone array capable of suppressing edge diffraction effects as recited in claim 1, wherein: the array panel and the back shell are made of lightweight materials with high acoustic impedance.
7. A microphone array capable of suppressing edge diffraction effects as recited in claim 1, wherein: the diameter of the array panel is 190 mm-510 mm; the thickness of the array panel is 4.9 mm-5.1 mm; the diameter of the micropores is 0.9 mm-1.1 mm; the hole distance between the micropores is 3.8 mm-4.2 mm; the depth of the cavity is 48 mm-52 mm.
8. A microphone array capable of suppressing edge diffraction effects as claimed in claim 2, wherein: the outermost microphone on the cantilever is arranged on a circumference taking the center of the array body as the center of the circle, and the diameter of the circumference is 450mm; the innermost microphone on the cantilever is on a circumference taking the center of the array body as a circle center, and the diameter of the circumference is 300mm.
9. A microphone array design method, characterized in that: key design parameters of the microphone array include the thickness of the array panel, the aperture of the micropores, the pitch between the micropores and the depth of the inner cavity; the microphone array design method comprises the following steps:
Placing the microphone array of any of claims 1 to 8 in front of a wind tunnel test model and acquiring the spectral characteristics of an aerodynamic noise source;
In the frequency band range of the pneumatic noise source energy distribution set, the maximum sound absorption coefficient is used as an objective function to acquire the optimal parameter through an optimization algorithm;
Wherein the objective function is:
；
，
，
，
；
Wherein alpha is the sound absorption coefficient; θ is the angle between the normal direction of the micropore and the incidence direction of the sound wave; k r,km is the acoustic resistivity constant and acoustic mass constant, respectively; ω=2pi f is the angular frequency of the sound wave, f is the frequency of the sound wave; c 0 = 340m/s is the speed of sound in air under standard conditions; μ=1.48× -5m2/s is the kinematic viscosity coefficient of air; phi is the perforation rate, which is the ratio of the perforation area to the total area; for round holes arranged in square, the perforation rate ; L is the thickness of the array panel; d is the pore diameter of the micropore; b is the pitch of the micropores; h is the depth of the inner cavity; rs is the ratio of acoustic resistivity; m is the acoustic mass; k is the puncture constant.
10. A microphone array design method as defined in claim 9, wherein: the optimization algorithm is one of a particle swarm algorithm and an ant swarm algorithm.
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| CN202410497855.3A CN118075668B (en) | 2024-04-24 | Microphone array capable of inhibiting edge diffraction effect and design method thereof |
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| CN202410497855.3A CN118075668B (en) | 2024-04-24 | Microphone array capable of inhibiting edge diffraction effect and design method thereof |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014236347A (en) * | 2013-05-31 | 2014-12-15 | パナソニック株式会社 | Sound pickup system |
| CN105004412A (en) * | 2015-07-20 | 2015-10-28 | 国家电网公司 | Improved system and method for transformer and reactor noise source positioning and vibration detection |
| US20170264999A1 (en) * | 2014-12-15 | 2017-09-14 | Panasonic Intellectual Property Management C., Ltd. | Microphone array, monitoring system, and sound pickup setting method |
| CN213186449U (en) * | 2020-10-27 | 2021-05-11 | 上海工程技术大学 | Dual-purpose detachable spiral sound array device |
| US20240015455A1 (en) * | 2014-01-06 | 2024-01-11 | Shenzhen Shokz Co., Ltd. | Systems and methods for suppressing sound leakage |
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014236347A (en) * | 2013-05-31 | 2014-12-15 | パナソニック株式会社 | Sound pickup system |
| US20240015455A1 (en) * | 2014-01-06 | 2024-01-11 | Shenzhen Shokz Co., Ltd. | Systems and methods for suppressing sound leakage |
| US20170264999A1 (en) * | 2014-12-15 | 2017-09-14 | Panasonic Intellectual Property Management C., Ltd. | Microphone array, monitoring system, and sound pickup setting method |
| CN105004412A (en) * | 2015-07-20 | 2015-10-28 | 国家电网公司 | Improved system and method for transformer and reactor noise source positioning and vibration detection |
| CN213186449U (en) * | 2020-10-27 | 2021-05-11 | 上海工程技术大学 | Dual-purpose detachable spiral sound array device |
Non-Patent Citations (1)
| Title |
|---|
| 周家检等: "基于麦克风阵列的运动声源识别技术", 《空气动力学学报》, 28 February 2022 (2022-02-28) * |
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