阅读说明：本技术 一种声学天线及其应用 (Acoustic antenna and application thereof ) 是由 赵胜东 董浩文 张娜莉 张传增 汪越胜 于 2021-08-05 设计创作，主要内容包括：本发明属于声学超材料领域。为了解决如何利用超表面来实现对宽频声波的调控的问题,本发明提供一种声学天线及其应用,该声学天线包括两种编码单元,这两种编码单元通过合理排布可以使透射声波产生相反的透射相位,该声学天线可根据辐射声波频率,将声波偏转至某一特定方向,当频率周期变化时,声波偏转方向可在一定角度内周期变化,从而形成扇形扫描区域。在进行声学探测时根据扫描区域内回波的频率来确定障碍物的方向,并根据回波时间以确定障碍物的距离。(The invention belongs to the field of acoustic metamaterials. The invention provides an acoustic antenna and application thereof, aiming at solving the problem of how to realize the regulation and control of broadband sound waves by utilizing a super surface. When the acoustic detection is carried out, the direction of the obstacle is determined according to the frequency of the echo in the scanning area, and the distance of the obstacle is determined according to the echo time.)

1. An acoustic antenna is characterized by comprising an acoustic super surface, wherein the acoustic super surface comprises a substrate and two coding units formed on one surface of the substrate, the bottom areas of the two coding units are the same and are arranged periodically, the coding units are formed by forming air channels between columnar bodies and columnar bodies, the wavelength of transmitted sound waves is larger than the thickness of the acoustic antenna, the transmitted sound waves have opposite transmission phases at the two coding units after being regulated and controlled by the air channels, the anti-phase characteristics of the transmitted sound waves are kept stable in a wide frequency range, and the beam radiation angle of the transmitted sound waves changes along with the change of acoustic radiation frequency, so that a sector scanning area is formed;

the positions of the columnar bodies in one of the code units are as follows: the bottom surface of the coding unit is divided into 60-42 grids, and the occupation of the columns is as follows: the first row is 1 to 60 lattices, the second row to the fifteenth row is 1 to 18 lattices, the sixteenth row is 1 to 18 lattices and 47 to 48 lattices, the seventeenth row is 1 to 18 lattices and 45 to 48 lattices, the eighteenth row is 10 to 18 lattices and 45 to 48 lattices, the nineteenth row is 12 to 19 lattices and 45 to 48 lattices, the twentieth row is 13 to 20 lattices and 43 to 48 lattices, the twentieth row is 14 to 20 lattices and 42 to 48 lattices, the twenty-twelfth row to twenty-third row is 14 to 48 lattices, the twenty-fourteenth row to twenty-sixth row is 13 to 48 lattices, the twenty-seventh row is 15 to 48 lattices, the twenty-eighth row is 16 to 41 lattices and 48 lattices, the twenty-ninth row is 19 to 40 lattices, the thirty row is 26 to 37 lattices, the thirty row is 26 to 36 lattices, and the forty-second row is 1 to 60 lattices;

the positions of the columns in another coding unit are as follows: the bottom surface of the coding unit is divided into 60-42 grids, and the occupation of the columns is as follows: the first row is 1 to 60 lattices, the second row to the fourteenth row is 26 to 31 lattices, the fifteenth row is 1 to 12 lattices and 26 to 31 lattices, the sixteenth row is 1 to 12 lattices and 27 to 31 lattices, the seventeenth row to the twenty-fourth row is 1 to 12 lattices and 28 to 31 lattices, the twenty-fifth row is 1 to 12 lattices, 28 to 31 lattices and 45 to 46 lattices, the twenty-sixth row is 1 to 12 lattices, 28 to 31 lattices and 45 to 47 lattices, the twenty-eighth row is 2 to 13 lattices, 28 to 31 lattices and 45 to 47 lattices, the twenty-ninth row is 2 to 13 lattices, 28 to 31 lattices and 45 to 50 lattices, the thirty row is 1 to 13 lattices, 26 to 31 lattices and 45 to 50 lattices, the twelfth row is 1 to 12 lattices, 25 to 31 lattices and 45 to 50 lattices, thirty-third rows are 1 to 12 lattices, 25 to 31 lattices and 45 to 52 lattices, thirty-fourth rows are 1 to 12 lattices, 25 to 27 lattices and 45 to 53 lattices, thirty-fifth rows are 1 to 12 lattices, 25 to 26 lattices and 45 to 54 lattices, thirty-sixth rows are 1 to 12 lattices and 45 to 54 lattices in thirty-ninth rows, forty rows are 1 to 12 lattices and 45 to 55 lattices, forty rows are 1 to 12 lattices and 45 to 56 lattices, and forty-twelfth rows are 1 to 60 lattices.

2. The acoustic antenna of claim 1, wherein the beam radiation angle θ is:

θ＝sin^-1(c/Lf_peri)

where c is the air sound velocity, L is the period length of the coding unit, f_periIs a periodically varying frequency of acoustic radiation.

3. An acoustic antenna according to claim 2, characterized in that the radiation angle of the acoustic antenna decreases with increasing frequency of the acoustic radiation.

4. The acoustic antenna of claim 1, wherein the two coding units are arranged alternately or in a checkerboard pattern.

5. The acoustic antenna according to claim 1, wherein the two coding units are arranged alternately, and each coding position includes 2 × 2 units, there are 4 units in a coding period, and the width of each unit is H, so that the coding period is L ═ 4H, and the deflection angle of the radiation beam is:

θ＝sin^-1(c/4Hf_peri)。

6. the acoustic antenna of claim 1, wherein the two coding units are arranged in a checkerboard pattern, and each coding position comprises 3 x 3 units, there are 9 units in a coding period, each unit has a width H, and the coding period isThe beam deflection angle is:

7. the acoustic antenna of claim 1, the cylinder being obtained by 3D printing.

8. The acoustic antenna of claim 1, applied to acoustic detection, wherein the direction of the obstacle is determined according to the frequency of the echo in the scanning area when the acoustic detection is performed, and the distance of the obstacle is determined according to the echo time.

Technical Field

The invention belongs to the field of acoustic metamaterials, and particularly relates to an acoustic antenna and application thereof.

Background

The coding acoustic super surface is a sub-wavelength coding acoustic super material, the sub-wavelength coding super material realizes the regulation and control of fluctuation, and the basis is the broadband design of a unit and the reconstruction of a coding sequence. The principle is that the patterning design of the phase distribution is realized by laying a sub-wavelength encoding unit on a material interface. The manual phase control technology opens a new door for fluctuation regulation and control, and extraordinary fluctuation performance such as negative refractive index, acoustic focusing, bending acoustic beams, spiral acoustic field, acoustic energy asymmetric transmission, near-zero refractive index stealth and the like can be realized by utilizing the super surface.

The traditional super surface can not be changed once being designed, the application frequency range of the super surface is narrow due to the fixed structure, the application is limited, the huge advantages of the super surface can not be fully exerted, and various super surface structures are needed corresponding to application occasions with wide frequency ranges, so that the cost is increased. The coded acoustic super-surface can quickly regulate and control a sound field, has great advantages compared with common materials in terms of coding characteristics, and has wide application prospects in the fields of acoustic antennas, noise control, national defense industry, architectural acoustics and the like. How to utilize the super surface to realize the regulation and control of the broadband sound wave is a technical problem which needs to be solved at present.

Disclosure of Invention

The invention aims to solve the problem of how to realize the regulation and control of broadband sound waves by utilizing a super surface, and provides an acoustic antenna and application thereof.

In order to achieve the purpose, the invention adopts the following technical scheme.

An acoustic antenna comprises an acoustic super surface, wherein the acoustic super surface comprises a substrate and two coding units formed on one surface of the substrate, the bottom areas of the two coding units are the same and are arranged periodically, the coding units are formed by cylindrical bodies and air channels formed between the cylindrical bodies, the wavelength of transmitted sound waves is larger than the thickness of the acoustic antenna, the transmitted sound waves have opposite transmission phases at the two coding units after being regulated and controlled by the air channels, the anti-phase characteristics of the transmitted sound waves are kept stable in a wide frequency range, and the beam radiation angle of the transmitted sound waves changes along with the change of sound radiation frequency, so that a sector scanning area is formed;

the positions of the columnar bodies in one of the code units are as follows: the bottom surface of the coding unit is divided into 60-42 grids, and the occupation of the columns is as follows: the first row is 1 to 60 lattices, the second row to the fifteenth row is 1 to 18 lattices, the sixteenth row is 1 to 18 lattices and 47 to 48 lattices, the seventeenth row is 1 to 18 lattices and 45 to 48 lattices, the eighteenth row is 10 to 18 lattices and 45 to 48 lattices, the nineteenth row is 12 to 19 lattices and 45 to 48 lattices, the twentieth row is 13 to 20 lattices and 43 to 48 lattices, the twentieth row is 14 to 20 lattices and 42 to 48 lattices, the twenty-twelfth row to twenty-third row is 14 to 48 lattices, the twenty-fourteenth row to twenty-sixth row is 13 to 48 lattices, the twenty-seventh row is 15 to 48 lattices, the twenty-eighth row is 16 to 41 lattices and 48 lattices, the twenty-ninth row is 19 to 40 lattices, the thirty row is 26 to 37 lattices, the thirty row is 26 to 36 lattices, and the forty-second row is 1 to 60 lattices;

the positions of the columns in another coding unit are as follows: the bottom surface of the coding unit is divided into 60-42 grids, and the occupation of the columns is as follows: the first row is 1 to 60 lattices, the second row to the fourteenth row is 26 to 31 lattices, the fifteenth row is 1 to 12 lattices and 26 to 31 lattices, the sixteenth row is 1 to 12 lattices and 27 to 31 lattices, the seventeenth row to the twenty-fourth row is 1 to 12 lattices and 28 to 31 lattices, the twenty-fifth row is 1 to 12 lattices, 28 to 31 lattices and 45 to 46 lattices, the twenty-sixth row is 1 to 12 lattices, 28 to 31 lattices and 45 to 47 lattices, the twenty-eighth row is 2 to 13 lattices, 28 to 31 lattices and 45 to 47 lattices, the twenty-ninth row is 2 to 13 lattices, 28 to 31 lattices and 45 to 50 lattices, the thirty row is 1 to 13 lattices, 26 to 31 lattices and 45 to 50 lattices, the twelfth row is 1 to 12 lattices, 25 to 31 lattices and 45 to 50 lattices, thirty-third rows are 1 to 12 lattices, 25 to 31 lattices and 45 to 52 lattices, thirty-fourth rows are 1 to 12 lattices, 25 to 27 lattices and 45 to 53 lattices, thirty-fifth rows are 1 to 12 lattices, 25 to 26 lattices and 45 to 54 lattices, thirty-sixth rows are 1 to 12 lattices and 45 to 54 lattices in thirty-ninth rows, forty rows are 1 to 12 lattices and 45 to 55 lattices, forty rows are 1 to 12 lattices and 45 to 56 lattices, and forty-twelfth rows are 1 to 60 lattices.

Further, the beam radiation angle θ is:

θ＝sin^-1(c/Lf_peri)

where c is the air sound velocity, L is the period length of the coding unit, f_periIs a periodically varying frequency of acoustic radiation.

Further, the radiation angle of the acoustic antenna decreases with increasing acoustic radiation frequency.

Further, the two coding units are arranged alternately or in a checkerboard manner.

Further, the two coding units are arranged alternately, and each coding position includes 2 × 2 units, there are 4 units in a coding period, and the width of each unit is H, then the coding period is L ═ 4H, and the deflection angle of the radiation beam is:

θ＝sin^-1(c/4Hf_peri)。

furthermore, the two coding units are arranged in a checkerboard manner, each coding position comprises 3 × 3 units, 9 units are arranged in one coding period, the width of each unit is H, and the coding period isThe beam deflection angle is:

furthermore, the columnar body is obtained by 3D printing of photosensitive resin, the method is simple and rapid, and the columnar body is formed in one step and has a production application prospect.

The invention also provides application of the acoustic antenna in acoustic detection, wherein the direction of an obstacle is determined according to the frequency of an echo in a scanning area during acoustic detection, and the distance of the obstacle is determined according to echo time.

The wide frequency range of the invention is 2000Hz-5000Hz, and the preferable wide frequency range is 2500Hz-4500 Hz.

The invention has the following beneficial effects: the different arrangement modes of the two coding units can form acoustic antennas with different functions. The acoustic antenna can deflect the sound wave to a specific direction according to the frequency of the radiated sound wave. When the frequency is periodically changed, the deflection direction of the sound wave can be periodically changed within a certain angle, so that a sector scanning area is formed. When acoustic detection is carried out, the direction of the obstacle can be determined according to the frequency of the echo in the scanning area, and the distance of the obstacle can be further determined according to the echo time. The acoustic antenna has important application prospects in the aspects of target detection, noise control and the like.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

Fig. 1 is a schematic diagram of the overall structure and principle of the novel acoustic antenna provided by the present invention;

FIG. 2 is a detailed geometry of a first type of coding unit;

FIG. 3 is a detailed geometry of a second type of coding unit;

FIG. 4 is a schematic diagram of occupying parts of a first type of coding unit;

FIG. 5 is a schematic diagram of the occupation of parts of a second type of coding unit;

FIG. 6 shows the effect of the acoustic antenna when the coding units are arranged alternately;

fig. 7 shows the effect of the acoustic antenna when the coding units are arranged checkerboard.

In the above figures, 1-coding unit of the first type; 2-coding units of the second type; 3-an acoustic antenna; 4-a columnar body; 5-air channel.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments and the accompanying drawings.

An acoustic antenna comprises an acoustic super-surface, as shown in fig. 1, the acoustic super-surface comprises a substrate made of a solid material and two coding units formed on one surface of the substrate: the first coding unit 1 and the second coding unit 2 have the same bottom area and are arranged periodically, and the first coding unit 1 and the second coding unit 2 are both composed of a columnar body 4 and an air channel 5 formed between the columnar bodies 4.

The shape and position of the pillars of the two coding units are different as shown in fig. 2-5. The two coding units are obtained by genetic algorithm optimization design. The bottom surfaces of the two coding units are respectively divided into 60 × 42 grids, and the occupation of the pillars of the first coding unit 1 is shown in fig. 3 as follows: the first row is 1 to 60 lattices, the second row to the fifteenth row is 1 to 18 lattices, the sixteenth row is 1 to 18 lattices and 47 to 48 lattices, the seventeenth row is 1 to 18 lattices and 45 to 48 lattices, the eighteenth row is 10 to 18 lattices and 45 to 48 lattices, the nineteenth row is 12 to 19 lattices and 45 to 48 lattices, the twentieth row is 13 to 20 lattices and 43 to 48 lattices, the twentieth row is 14 to 20 lattices and 42 to 48 lattices, the twenty-twelfth row to the twenty-third row is 14 to 48 lattices, the twenty-fourteenth row to the twenty-sixth row is 13 to 48 lattices, the twenty-seventh row is 15 to 48 lattices, the twenty-eighth row is 16 to 41 lattices and 48 lattices, the twenty-ninth row is 19 to 40 lattices, the thirty row is 26 to 37 lattices, the thirty row is 26 to 36 lattices, and the forty-second row is 1 to 60 lattices.

The occupation space of the columnar bodies of the second coding unit 2 is shown in fig. 5, the first row is 1-60 lattices, the second row is 26-31 lattices, the fifteenth row is 1-12 lattices and 26-31 lattices, the sixteenth row is 1-12 lattices and 27-31 lattices, the seventeenth row is 1-12 lattices and 28-31 lattices, the twenty-fifth row is 1-12 lattices, 28-31 lattices and 45-46 lattices, the twenty-sixth row is 1-12 lattices, 28-31 lattices and 45-47 lattices, the twenty-eighth row is 2-13 lattices, 28-31 lattices and 45-47 lattices, the twenty-ninth row is 2-13 lattices, 28-31 lattices and 45-50 lattices, the thirty row is 1-13 lattices, 26-31 lattices and 45-50 lattices, thirty-second rows of 1-12 lattices, 25-31 lattices and 45-50 lattices, thirty-third rows of 1-12 lattices, 25-31 lattices and 45-52 lattices, thirty-fourth rows of 1-12 lattices, 25-27 lattices and 45-53 lattices, thirty-fifth rows of 1-12 lattices, 25-26 lattices and 45-54 lattices, thirty-sixth rows of 1-12 lattices and 45-54 lattices, forty rows of 1-12 lattices and 45-55 lattices, forty rows of 1-12 lattices and 45-56 lattices and forty-twelfth rows of 1-60 lattices.

The wavelength of the transmitted sound wave is larger than the thickness of the acoustic antenna, the transmitted sound wave has opposite transmission phases at the two coding units after being regulated and controlled by the air channel, the anti-phase characteristics of the transmitted sound wave are kept stable in a wide frequency range, and the radiation angle of the wave beam of the transmitted sound wave changes along with the change of the sound radiation frequency, so that a sector scanning area is formed.

The beam radiation angle θ is:

θ＝sin^-1(c/Lf_peri)

where c is the air sound velocity, L is the period length of the coding unit, f_periIs a periodically varying frequency of acoustic radiation. The radiation angle of the acoustic antenna decreases with increasing acoustic radiation frequency.

The sound waves can be radiated along a certain direction through reasonable arrangement of the two coding units, the radiation angle is related to the frequency, and the radiation frequency with periodic change enables the sound radiation angle to be also in periodic change. Therefore, when acoustic detection is carried out, the direction of the obstacle can be determined according to the frequency of the echo in the scanning area, and the distance of the obstacle can be further determined according to the echo time.

Examples 1 to 2

Fig. 6 and 7 show an embodiment 1-2 of the acoustic antenna of the present invention, and the specific geometric dimensions of each coding unit in embodiment 1-2 are as shown in fig. 2 and 3, and for each coding unit, the thickness D in the sound wave transmission direction is 0.06m, and the width H of each coding unit is 0.041m, which are obtained by 3D printing of a photosensitive resin.

In embodiment 1, as shown in fig. 6, the coding arrangement of the acoustic antennas is an alternate arrangement, and each coding position includes 2 × 2 units, so that if there are four units in a coding period, the coding period is L ═ 4H, so that the deflection angle θ of the radiation beam is:

θ＝sin^-1(c/4Hf_peri)

the radiation sound wave frequencies are different, the deflection angles theta of the sound beams are different, and the simulation results of 2500Hz,3500Hz and 4500Hz are shown in FIG. 6. It can be seen that under the condition that the coding units are alternately arranged, the sound radiation wave beam is divided into two beams, and the deflection angle theta is along with the frequency f_periIs increased and decreased, the radiation angle is between 27.7 and 56.8 degrees.

Embodiment 2, as shown in fig. 7, the coding arrangement of the acoustic antennas is a checkerboard arrangement, each coding position includes 3 × 3 units, and the equivalent coding period isThe beam deflection angle is therefore:

also, the beam deflection angle θ is frequency dependent, and FIG. 7 shows the simulation results for 2700Hz,3500Hz, and 4400 Hz. It can be seen that in the case of checkerboard arrangement of the coding units, the acoustic radiation beams are four, and the deflection angle θ follows the frequency f_peri increases and decreases with a radiation angle between 26.6 deg. and 46.9 deg..

The acoustic antenna can deflect the sound wave to a specific direction according to the frequency of the radiated sound wave. When the frequency is periodically changed, the deflection direction of the sound wave can be periodically changed within a certain angle, so that a sector scanning area is formed. When acoustic detection is carried out, the direction of the obstacle can be determined according to the frequency of the echo in the scanning area, and the distance of the obstacle can be further determined according to the echo time. Therefore, the broadband acoustic antenna has important application prospects in the aspects of target detection, noise control and the like.

The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solution of the present invention by those skilled in the art should fall within the protection scope defined by the claims of the present invention without departing from the spirit of the present invention.