A cross-domain wireless acoustic communication system and method based on acoustic holography

Abstract

The present invention discloses a wireless cross-domain acoustic communication system and method based on acoustic holography. The acoustic holographic device used for cross-domain acoustic communication consists of a single-layer acoustic holographic phase plate, an array transducer, and a camera vision module, wherein each array element of the array transducer has two states: on / off. After receiving the communication coding signal transmitted in the water, the transducer array elements at the corresponding positions can be sequentially selected and the dynamic regulation of the incident sound field can be realized. Then, the sound is transmitted to the water-air interface through the single-layer holographic phase plate and phase-modulated. Under the action of the acoustic radiation force, the interface will deform. The camera vision module is used to capture and parse and decode the deformation of the water surface, completing the wireless reception of information across the water-air interface. The present invention can directly transmit underwater information to the air. The equipment is simple and the relative position requirements of the transmitting and receiving devices are not strict. It is applicable to liquid environments of any temperature, salinity, and density.

Description

Technical Field

[0001] The present invention relates to a cross-domain communication technology, specifically a cross-domain wireless acoustic communication system and method based on acoustic holography. Background Art

[0002] While traditional wireless communication technologies (such as radio frequency, optical, and acoustic communications) can achieve efficient, real-time communication between multiple underwater anchor points, due to the significant differences in physical properties between the upper and lower water areas, these methods are unable to achieve effective, real-time communication between underwater sensors and aerial nodes. Therefore, water-to-air cross-domain communication remains a difficult problem in the field of marine communications. A breakthrough in this technology will provide rich and valuable data resources for research in areas such as marine biology, climate change, and seabed resources. This is particularly important for maintaining real-time, efficient, and stable communication between dynamic underwater devices such as submersibles and unmanned underwater vehicles (AUVs) and aerial devices such as drones or satellite communications. Therefore, achieving real-time, efficient, and highly secure wireless cross-domain transmission of underwater information has important scientific significance and practical application value.

[0003] Currently, sonar-based acoustic communication technology is a commonly used means of underwater communication, with advantages such as long transmission distance and stable transmission. However, acoustic information transmitted underwater cannot be directly transmitted to the air domain, mainly because the sound waves will be severely reflected at the water-air interface, making it difficult to directly establish communication with air nodes. To address this problem, some researchers have achieved effective transmission of underwater information by deploying underwater relay equipment, cross-domain vehicles, and coordinated communication of acoustic and RF signals. However, these technologies still have significant limitations: low communication efficiency, strong dependence on equipment, susceptibility to waves and water currents, and high environmental requirements. Therefore, how to achieve real-time communication and data transmission in underwater and above-water areas while minimizing the number of signal relay devices has become a technology that urgently needs breakthroughs. Summary of the Invention

[0004] In order to overcome the dilemma that existing underwater acoustic communication means cannot realize cross-domain information transmission, and to address the shortcomings of existing composite means such as photoacoustics, acousto-electromagnetic, etc. in cross-domain information transmission, such as poor stability, low security and complex equipment, the present invention provides a solution of a cross-domain wireless acoustic communication system and method based on dynamic acoustic holography.

[0005] Existing technologies have difficulty effectively transmitting wireless signals, such as acoustic and electromagnetic waves, from transducers and sonar systems across different media domains. For example, it's difficult to effectively transmit signal information from water to air, or vice versa, and underwater ripples can't be transmitted to the surface. This paper designs a cross-domain wireless acoustic communication system and method that uses acoustic holographic structures to propagate signals between different media domains, resolving these technical challenges.

[0006] It is known that ultrasound, as a mechanical wave, will cause compression-stretching changes in the background domain material when it acts on matter, and thus will cause liquid surface deformation when it acts on the water-air interface. Among them, the present invention uses a dynamic holographic sound field to dynamically control the liquid surface deformation, and visually visualizes the liquid surface deformation in the air domain, thereby realizing wireless end-to-end reading of underwater information in the air domain and completing cross-domain wireless acoustic communication. Based on the background technology, the present invention utilizes the mechanical properties of sound waves and their ability to cause deformation due to acoustic radiation force on the liquid surface to carry out cross-domain wireless acoustic communication at the water-air interface. By using a visual method in the air domain to directly and efficiently read the liquid surface deformation information in real time and decode the transmission information content of the underwater device, the communication stability in the water surface fluctuation environment can be significantly improved, without the need for the equipment to frequently surface, and low requirements for neutrality.

[0007] This invention, based on spatial multiplexing of incident acoustic fields, combines a partitioned electrode array transducer with incident acoustic field coding modulation characteristics with a conventional fixed holographic phase plate to further achieve dynamic control of the holographic acoustic field and its dynamic liquid surface deformation. Furthermore, it utilizes a camera vision module to enable fast and efficient reading and writing of underwater information, and compiles text messages transmitted underwater. In summary, by dynamically and highly resolving the acoustic field and its deformation at the water-air interface, cross-domain reading of underwater information is possible, effectively overcoming the propagation barriers of traditional acoustic communication technologies at the water-air interface.

[0008] The technical solution of the present invention is:

[0009] 1. A cross-domain wireless acoustic communication system based on acoustic holography:

[0010] The invention comprises a partitioned electrode array transducer, which is placed under liquid water and is used to transmit acoustic wave signals to a single-layer acoustic holographic phase plate;

[0011] It includes a single-layer acoustic holographic phase plate, which is also placed under the liquid and above the partitioned electrode array transducer, and is arranged close to the liquid surface, for receiving the acoustic wave signal and feeding it back to the liquid surface to form a liquid surface pattern;

[0012] The method comprises a camera vision module, which is placed in the air domain and faces the liquid surface above the single-layer acoustic holographic phase plate, and is used for visually capturing and processing the liquid surface pattern on the liquid surface, and analyzing the liquid surface pattern to obtain information of the acoustic wave signal.

[0013] The single-layer acoustic holographic phase plate and the probe end surface of the partitioned electrode array transducer are arranged in parallel with an axial distance along the propagation direction.

[0014] The distance between the single-layer acoustic holographic phase plate and the probe end face of the partitioned electrode array transducer can be on the order of several centimeters, specifically tens to hundreds of times the working wavelength.

[0015] It also includes an information transmitting point and a switch control module. The information transmitting point can be placed below the liquid surface. The information transmitting point is electrically connected to the partitioned electrode array transducer via the switch control module. The information transmitting point transmits the original excitation signal, and the partitioned electrode array transducer is controlled by the switch control module to emit an acoustic wave signal corresponding to the liquid surface pattern.

[0016] The partitioned electrode array transducer has a piezoelectric device inside. The piezoelectric device uses a dicing machine to evenly and discretely divide the electrodes on one side of itself into multiple independent array elements. All array elements are connected to a switching circuit. The switching circuit code controls the electrical connection and disconnection of each array element, thereby realizing dynamic coding and regulation of the incident sound wave distribution under a single electrical signal input, so that the liquid surface pattern display is subdivided into different positions for different displays.

[0017] The deformation of the liquid surface caused by the acoustic radiation force is entirely determined by the spatial sound field distribution reconstructed by the combined action of the single-layer acoustic holographic phase plate and the array transducer. During cross-domain communication, the single-layer acoustic holographic phase plate remains fixed throughout, while the partitioned electrode array transducer can be dynamically regulated by electrical coding to achieve dynamic reconstruction of the incident sound field.

[0018] After the incident sound field from the single-layer acoustic holographic phase plate reconstructs the target sound field at the water-air interface, the acoustic radiation force causes the liquid surface to vibrate, resulting in corresponding water surface ripples. The height of these ripples is related to the acoustic energy distribution of the ultrasonic field. Therefore, the ripples can be controlled by adjusting the acoustic field distribution at the water-air interface.

[0019] Taking into account that changes in water surface ripples will cause different light reflections, a camera vision module is arranged above the water surface to achieve real-time dynamic capture of water surface ripple changes, and the information encoded in the water surface ripples is decoded through template matching method; therefore, by real-time capture of the ripple pattern on the water-air interface, text information transmitted underwater can be read in real time, efficiently and wirelessly.

[0020] The single-layer acoustic holographic phase plate is made of polymer using a 3D printing method, with one side having a concave-convex surface and the other side having a flat surface.

[0021] The specific polymer is made of conventional photosensitive resin material and prepared by traditional 3D printing technology.

[0022] The single-layer acoustic holographic phase plate is mainly composed of a substrate and a concave-convex structure located on the substrate.

[0023] 2. A cross-domain wireless acoustic communication method of a cross-domain wireless acoustic communication system, the method comprising:

[0024] The partitioned electrode array transducer is excited to emit an incident ultrasonic sound wave, which is phase-modulated after propagating to the single-layer acoustic holographic phase plate and then continues to propagate forward to the interface between different medium domains, such as the water-air interface. The interface between different medium domains undergoes different surface deformations under the action of the acoustic radiation force, and holographic sound field reconstruction is achieved on the interface;

[0025] At the same time, the camera vision module above the interface is used to visually capture, collect and decode the surface deformation of the interface, so as to directly extract and read the underwater acoustic wave information on the liquid surface, and finally realize end-to-end cross-domain wireless acoustic communication between the underwater and surface equipment.

[0026] The partitioned electrode array transducer emits different incident ultrasonic sound waves in sequence at different times, and forms different surface deformation patterns on the interface in sequence through the single-layer acoustic holographic phase plate. The camera vision module visually captures the surface deformation pattern of the interface in sequence to obtain a visual image, and performs image analysis processing on the visual image captured in sequence to obtain dynamic information.

[0027] The incident ultrasonic sound waves emitted by the partitioned electrode array transducer act on the interface through the single-layer acoustic holographic phase plate to form a surface deformation pattern of the "seven-segment tube" pattern code. The "seven-segment tube" pattern code has a time-sharing multiplexing characteristic, specifically:

[0028] The "seven-segment tube" pattern is the character "8", with each edge segment of the character "8" as a sub-unit for coding. The coding relationship in the following table controls the display of all different sub-units, thereby correspondingly presenting different letters and numbers on the interface:

[0029] A B C D E F G H I Upper right vertical line Upper left and upper right vertical lines Upper and lower horizontal lines Upper right vertical line + middle horizontal line Upper right and lower right vertical lines Upper horizontal line + lower right vertical line Upper right and lower left vertical lines Upper and lower horizontal lines + lower right vertical line Upper, middle, and lower horizontal lines J K L M N O P Q R Upper left, upper right, and lower right vertical lines Middle horizontal line + upper right and lower right vertical lines Upper horizontal line + upper right and lower right vertical lines Upper horizontal line + upper left and upper right vertical lines Upper horizontal line + lower left and lower right vertical lines Upper and middle horizontal lines + upper left and upper right vertical lines Upper left, upper right, lower left, lower right vertical lines Upper, middle, and lower horizontal lines + upper right vertical line Upper right, lower left, and lower right vertical lines S T U V W X Y Z 0 Upper and middle horizontal lines + upper right and lower right vertical lines Upper left and upper right vertical lines + middle and lower horizontal lines Upper and middle horizontal lines + upper left and lower right vertical lines Upper and lower horizontal lines + upper right and lower right vertical lines Upper and lower horizontal lines + upper left and upper right vertical lines Upper right, lower left, lower right vertical lines + lower horizontal line Upper and lower horizontal lines + upper right and lower left vertical lines Upper and middle horizontal lines + upper left, upper right, and lower right vertical lines Upper, middle, and lower horizontal lines + upper right and lower left vertical lines 1 2 3 4 5 6 7 8 9 Upper, middle, and lower horizontal lines + upper right and lower right vertical lines Top, middle, and bottom horizontal lines + top left and top right vertical lines Upper horizontal line + upper left, upper right, lower left, lower right vertical lines Middle horizontal line + upper left, upper right, lower left, lower right vertical lines Upper and lower horizontal lines + upper left, upper right, and lower left vertical lines Middle and lower horizontal lines + upper left, upper right, and lower left vertical lines Upper and middle horizontal lines + upper left, upper right, lower left, and lower right vertical lines Upper and lower horizontal lines + upper left, upper right, lower left, and lower right vertical lines Top, middle, and bottom horizontal lines + top left, top right, bottom left, and bottom right vertical lines

[0030] The above 36 characters, consisting of letters A to Z and numbers 0 to 9, can be transformed into a code book for encoding and decoding.

[0031] The time-division multiplexing feature means that you can selectively choose whether to display or not display in the time dimension.

[0032] According to the solution of the present invention, actual tests have shown that it takes approximately 0.3s to 0.5s to display an "8" character, so the frame rate is 2-3 characters per second.

[0033] In the solution of the present invention, a "seven-segment tube" pattern is specially designed to enable the liquid surface deformation to have time-sharing multiplexing characteristics, which can be combined with the system to perform cross-domain communication more efficiently.

[0034] The liquid surface deformation uses a "seven-segment tube" pattern with time-sharing multiplexing characteristics, which can be regarded as a combination of seven independent sub-units. Each edge segment of the "8" character is used as a sub-unit and can be selectively displayed dynamically during the entire communication process. The camera vision module can read the text information transmitted underwater in real time after collecting and decoding the combined pattern displayed on the water surface.

[0035] The spatially selective display of the seven sub-units of the "seven-segment tube" pattern combines 36 different patterns, which are used to encode 26 letters and 10 numbers, realizing encrypted cross-domain transmission of text information. There is no need to control the direction of visual acquisition, and visual acquisition in any direction is unique.

[0036] The "seven-segment tube" pattern contains 7 different independent binary coding units, all of which can form a total of 2 7 However, in these cases, many patterns are symmetrical to each other and similar from many angles. The present invention only provides 36 different pattern codes, and these patterns are uniquely corresponding, and there is no possibility of similarity or duplication.

[0037] The fixed single-layer acoustic holographic phase plate integrates the fused phase information corresponding to the "seven-segment tube" pattern into its phase distribution, and each subunit of the "seven-segment tube" pattern is time-sharedly selected by the partitioned electrode array transducer; and after the camera vision module visually captures the image of the liquid surface pattern on the water surface, it uses a convolutional neural network model to recognize and process the image to obtain the "seven-segment tube" pattern information.

[0038] In a specific implementation, the position between the partitioned electrode array transducer and the single-layer acoustic holographic phase plate remains fixed, and the relative distance between the transducer and the water surface remains as constant as possible.

[0039] After the partitioned electrode array transducer receives information of any underwater target in situ in the form of a 0 / 1 data stream, it automatically transforms into a transducer array excitation coding array and triggers the generation of a corresponding incident sound field. After being controlled by the single-layer acoustic holographic phase plate, the corresponding "seven-segment tube" situation is reconstructed on the water surface. After being received by the camera vision module in the air domain, the information is decoded and read.

[0040] In summary, the implementation process of cross-domain wireless acoustic communication at the water-air interface based on dynamic acoustic holography in the present invention can be divided into the following three steps:

[0041] (1) Underwater information encryption: First, according to the number of array elements N×N of the electrode partition array transducer, the 36 letters and digital text information are encoded into N 2Then, according to the text information that the underwater base station needs to transmit, the corresponding binary data stream is sent to the electrode partition array transducer to control the excitation of each array element.

[0042] (2) Ultrasonic field dynamic excitation and interface reconstruction: The electrode partition array transducer receives the binary data stream in N 2 The bit data, representing a character, is first expanded into an N×N matrix of 0 / 1 data and input into the switching system, which controls the activation / deactivation of each element of the partitioned electrode array transducer, thereby stimulating the generation of the target incident acoustic field. The stimulated incident acoustic field then passes to the single-layer acoustic holographic phase plate, undergoing phase modulation and continuing to propagate into the far field, reconstructing the target acoustic field at the water-air interface. Due to the acoustic radiation force, the liquid surface deforms, exhibiting distinct "seven-segment tube" patterns.

[0043] (3) Reading of water surface ripple information in the air domain: Then, the camera vision module arranged in the air domain is used to collect the ripple conditions on the liquid surface and input them into the trained convolutional neural network. The captured ripple data is pattern matched and matched with the ripple conditions corresponding to 36 numbers and text information to decode the text information transmitted underwater.

[0044] When a string of text information consisting of m characters is transmitted underwater, the underwater signal transmitting station will transmit a string of m×N characters to the dynamic acoustic holographic device. 2 The binary data stream is encoded and converted into corresponding m N×N 0 / 1 matrices, and the electrode partition array transducer is stimulated once at different frame rates to generate a corresponding incident sound field. After being combined with the single-layer acoustic holographic phase plate, m corresponding "seven-segment tube" multiplexing patterns are reconstructed on the liquid surface in sequence. The camera vision module in the air domain is used to capture the ripple deformation on the liquid surface frame by frame in real time and decode the output. Then, the text information consisting of m characters transmitted by the underwater signal transmitting station is read to complete the water-air cross-domain wireless acoustic communication.

[0045] To achieve optimized time-division multiplexing encoding of 36 letters and numeric text at the same time, the specific process designed is as follows:

[0046] (1) First, the “seven-segment tube” pattern is divided into seven independent components, which are regarded as seven target sound fields P1 0 ~ P7 0 , is an n×n matrix. Based on the principle of uniform acoustic energy, the electrode partition excitation areas corresponding to each component are selected as evenly as possible, recorded as A1~A7, and is an N×N 0 / 1 matrix used to control the point coding of the electrode partition array transducer. Where N< <n。

[0047] (2) Then, the seven target sound fields P1 0 ~ P7 0 The seven electrode partition excitation conditions A1~A7 are brought into the multi-plane iterative angular spectrum method to optimize the design of the coded phase distribution on the single-layer acoustic holographic phase plate. φ b The multi-plane iterative angular spectrum method design process is divided into forward propagation and backward propagation processes.

[0048] Before the iterative optimization begins, the phase distribution on the single-layer acoustic holographic phase plate is φ b Set to an arbitrary value (n × n pixels) and divide the partition electrode array transducer plane into the same spatial dimensions z =0 excitation sound field distribution p 0i ( x , y , z =0)= A i Expanded to an n×n matrix, calculated by Fourier transform z =0 plane spectrum distribution: P 0i ( k x , k y , z =0)=∫∫ p 0i ( x , y , z =0)d x d y ; and multiply this spectrum by the phase factor H ( k x , k y , z = l )=e^( jk z l ), calculate the positive direction of the z-axis to the incident side plane of the single-layer acoustic holographic phase plate z = l Spectrum distribution of: P ’ i ( k x , k y , z = l )= P 0i (k x , k y , z =0)* H ( k x , k y , z = l ),in k z = ( k 0 2 - k x 2 - k y 2 ) 1 / 2 Then, the sound field distribution of the incident side plane of the single-layer acoustic holographic phase plate is obtained by inverse Fourier transform. p i ’ ( x , y , z = l )=∫∫ P ’ i ( k x , k y , z = l )d k x d k y .

[0049] The forward propagation process of the multi-plane iterative angular spectrum method is as follows: Therefore, the transmission side sound field distribution of the single-layer acoustic holographic phase plate can be expressed as: p i ’’ ( x , y , z = l )= p i ’ ( x , y , z = l )*e^( jφ b ). Also use Fourier transform to calculate the spectrum distribution of this plane: P i ’’ (k x , k y , z = l )=∫∫ p i ’’ ( x , y , z = l )d x d y , and continue to extrapolate along the positive z-axis to the target plane z = L Spectrum distribution on: P i ’’’ ( k x , k y , z = L )= P i ’’ ( k x , k y , z = l )* H ( k x , k y , z = L-l ), and then use the inverse Fourier transform to calculate z = L Sound field distribution on: p i ’’’ ( x , y , z = L )=∫∫ P i ’’’ ( k x , k y , z = L )d k x d k y .

[0050] After the forward propagation is completed, the target image plane z = L Phase on φ i ’’’ ( x,y , z = L )= arg ( p i ’’’ ( x , y , z = L ))Reserved, of which, arg () is the phase extraction function. At the same time, its amplitude is replaced by the target sound field distribution; we get z = L Sound field on the surface q i ’’’ ( x,y , z = L )=*e^(j φ i ’’’ ( x,y , z = L )).

[0051] The back propagation process is as follows: Calculate the target plane through Fourier transform z = L Spectrum distribution of: Q i ’’’ ( k x , k y , z = L )=∫∫ q i ’’’ ( x,y , z = L )d x d y , and then multiply the spectrum by the phase factor H ( k x , k y , z =( l-L ))=e^( jk z ( l-L )) and then calculate the negative extrapolation along the z-axis to the transmission side plane of the single-layer acoustic holographic phase plate z = l Spectrum distribution on Qi ’’ ( k x , k y , z = l )= Q i ’’’ ( k x , k y , z = L )* H ( k x , k y , z =( l-L )) The sound field distribution of the transmission side of the single-layer acoustic holographic phase plate is obtained by inverse Fourier transform calculation q i ’’ ( k x , k y , z = l )=∫∫ Q i ’’ ( k x , k y , z = l )d k x d k y Based on the sound field distribution on the incident side of the single-layer acoustic holographic phase plate p i ’ ( x , y , z = l ), the fused phase distribution on the single-layer acoustic holographic phase plate is calculated as: φ 0=∑ arg ( q i ’’ ( k x , k y , z = l )* conj ( p i’ ( x , y , z = l ))),in conj () is the conjugate function.

[0052] And the fusion phase distribution φ 0 is binarized, and the updated binary phase distribution is φ b =0 or π, when cos( φ 0)>0, φ b =0; when cos( φ 0)<=0, φ b =π.

[0053] After approximately 60 forward and backward propagation iterations, the coded fusion phase distribution on the single-layer acoustic holographic phase plate is finally obtained. φ b .

[0054] Based on the above-mentioned coded fusion phase distribution, the single-layer acoustic holographic phase plate is prepared. Based on the three-medium theory, the thickness of the coding thickness unit of the spatial array is set to h 1 and h 2 , the design process is as follows:

[0055] Set the operating frequency to f , the incident plane wave passes through the thickness h 1 and h 2 The transmitted sound field after the two coding units can be expressed as: P 1 =e^ i ( k 0 h 1 )and P 2 =e^ i ( k 0 h 2 ). And the phase difference between the two should satisfy: φ =arg( P 1 - P 2 )=π.

[0056] According to the above determined unit thickness h1 and h 2 Based on the coding fusion phase distribution φ b 3D printing is performed to finally obtain the single-layer acoustic holographic phase plate that can be used for phase modulation of the incident sound field.

[0057] At the same time, the electrode on one side of the conventionally polarized ultrasonic piezoelectric sheet is discretely separated into N×N independent units using a dicing machine, and the leads of each independent area are led out using a flexible circuit board and fixed in the housing. After the matching layer and backing are deposited on both sides respectively, the electrode partition array transducer with N×N independent units is prepared.

[0058] In actual working conditions, the electrode partition array transducer and the single-layer acoustic holographic phase plate are spaced z = l The array elements are placed parallel to each other at a distance of 1 / 4 of the vertical axis, and the ends of the leads on the flexible circuit board are connected to the switching circuit to realize the electrical coding control of the single-channel input ultrasonic excitation signal, control the connection / disconnection of each array element, and realize real-time electrical control of the incident sound field.

[0059] In this invention, each element of the array transducer has two states: on / off. Upon receiving a coded communication signal transmitted underwater, the corresponding transducer elements are sequentially selected, dynamically controlling the incident acoustic field. The controlled incident acoustic wave then propagates forward to the single-layer holographic phase plate, undergoing phase modulation before propagating to the water-air interface. Under the influence of the acoustic radiation force of this planar acoustic field, the water surface deforms. At this point, image recognition equipment can be used in the air domain to capture and process this deformation, enabling direct reception of underwater information in the air domain and completing wireless information reception across the water-air interface.

[0060] This invention utilizes a zoned electrode array transducer with spatially multiplexed incident acoustic fields, combined with a conventional acoustic holographic phase plate, to achieve dynamic, real-time reconstruction of the target plane's holographic acoustic field. Due to its mechanical properties, the spatially reconstructed holographic acoustic field, acting on the water-air interface, produces corresponding surface deformations on the liquid surface. A camera vision module positioned in the air domain above the liquid surface then captures these surface deformations and decodes their encoded information, enabling wireless, real-time, cross-domain reading of underwater information.

[0061] The dynamic acoustic holography system directly controls the shape of water surface ripples through the coding control electrode partition array transducer, and transmits underwater information directly and wirelessly to the air domain. It has a compact structure, high resolution, and good real-time performance. It can directly read underwater information from any angle through the existing camera vision module, has strong operability and simple equipment.

[0062] Moreover, in terms of implementation, based on the spatial multiplexing technology of incident sound waves, an electrode-partitioned array transducer is used to realize the dynamic control of the incident sound field under the excitation of a single ultrasonic signal, and combined with an axially parallel fixed holographic phase plate to realize the dynamic reconstruction of the holographic sound field, so that the liquid surface shows the dynamic changes of water surface ripples. Through the time-sharing multiplexing of each unit part of the "seven-segment tube" pattern, 36 letters and digital information can be encoded into the ripple situation. And by encoding the excitation area of ​​each array element of the electrode-partitioned array transducer, the target reproduction of the ripple pattern on the water surface is achieved, and the camera vision module is directly used to read and decode the text information transmitted underwater.

[0063] The entire communication process of the present invention includes: underwater acoustic information communication - encoded excitation of the partitioned electrode array transducer - liquid surface acoustic field reconstruction - acoustic radiation force-induced liquid surface deformation - camera vision system recognition and decoding. In summary, based on the above-mentioned dynamic acoustic holographic device with the ability to dynamically control the sound field, researchers can simply and conveniently use visual means to read underwater information wirelessly and in real time, realizing wireless cross-domain acoustic communication between surface and underwater, which is of great significance to modern ocean research, marine resource development, military applications and other fields.

[0064] The cross-domain wireless acoustic communication solution based on dynamic acoustic holography provided by the present invention has the following beneficial effects:

[0065] (1) Based on the acoustic radiation force, the present invention transforms the ultrasonically induced liquid surface deformation into a transmission medium to establish direct communication between a conventional underwater sonar system and an above-water optical system. Using simple devices, underwater-air cross-domain wireless acoustic communication can be achieved.

[0066] The method can achieve real-time and efficient air-to-air transmission of underwater information without the need for the relay system to surface. It has the characteristics of high security, high real-time performance and simple structure, and can effectively promote the development of marine resource exploration, deep-sea operations and salvage.

[0067] (2) The dynamic acoustic holography system used in the present invention has a compact structure, strong operability, and high reliability. The entire acoustic holography system only requires an ultrasonic transducer and an acoustic holographic phase plate arranged in parallel. Under the condition of a single ultrasonic signal input, the spatial electrical encoding of each array element can achieve rapid changes in the shape of water surface ripples, with a frame rate of tens of thousands of frames. At the same time, using the "seven-segment tube" as a text information encryption transmission pattern can realize encrypted transmission of underwater information, which has the advantage of high security.

[0068] The wireless cross-domain acoustic communication device based on acoustic holography proposed in the present invention can directly transmit underwater information into the air. The device is simple and has no strict requirements on the relative position of the transmitting and receiving devices. It is suitable for liquid environments of any temperature, salinity and density. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] To more clearly illustrate the embodiments of the present invention and its design, the following briefly introduces the drawings required for this embodiment. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0070] Figure 1 This is a schematic diagram of the cross-domain wireless acoustic communication technology based on dynamic acoustic holography in Examples 1 and 2 of the present invention.

[0071] Figure 2 1 is a flowchart of a partitioned electrode array transducer and its preparation process according to embodiments 1 and 2 of the present invention, wherein (a) shows the electrodes on one side of the piezoelectric sheet being discretized into independent partitioned electrodes, (b) shows a flexible circuit board for independently controlling the electrical signal input of each partitioned electrode, and (c) shows welding the flexible circuit board to the partitioned electrodes;

[0072] Figure 3 This is a flowchart of the electrode excitation areas and designed coding fusion phase distribution design corresponding to each component unit of the "seven-segment tube" in Examples 1 and 2 of the present invention, where (a) represents the electrode areas corresponding to the a to g components of the "seven-segment tube", (b) the incident sound field generated by the local area excitation of the partitioned electrode transducer, after being modulated by the fixed acoustic holographic phase plate, reconstructs part a of the "seven-segment tube" on the target plane, and (c) represents different partitioned electrode excitation areas and the target sound field patterns reconstructed therefrom on the target plane.

[0073] Figure 4 These are three-dimensional and two-dimensional structural diagrams of the single-layer acoustic holographic phase plate of Examples 1 and 2 of the present invention, wherein (a) represents the three-dimensional structural diagram of the acoustic holographic phase plate, and (b) represents the cross-sectional diagram of the acoustic holographic phase plate along the AA plane.

[0074] Figure 5 This is the time-division multiplexing "seven-segment tube" pattern and the corresponding electrode excitation conditions corresponding to the 36 letters and digital information in Examples 1 and 2 of the present invention.

[0075] Figure 6 It is a full flow chart of encoding and air domain decoding of character information and text information in embodiments 1 and 2 of the present invention.

[0076] Figure 7 It is the holographic sound field reconstruction result and experimental result diagram of the present invention.

[0077] Figure 8 This is a schematic diagram of a static cross-domain wireless acoustic communication process for the letter "H" in Example 1;

[0078] Figure 9This is a schematic diagram of the dynamic cross-domain wireless acoustic communication process for the "123HELLO" text data in Example 2.

[0079] Description of reference numerals:

[0080] Information transmission point 1, switch control module 2, partitioned electrode array transducer 3, single-layer acoustic holographic phase plate 4, camera vision module 5. DETAILED DESCRIPTION

[0081] To enable those skilled in the art to better understand the technical solutions of the present invention and implement them, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It is apparent that the embodiments described are only some of the embodiments of the present invention, and not all of them. All other embodiments derived by those skilled in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0082] In the description of the present invention, it is necessary to understand that the terms "middle", "upper", "lower", "left", "right", "lateral", "longitudinal", "horizontal", "vertical", "axial", "mirror", "length", "width", "thickness" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the technical solutions of the present invention and simplifying the description, and do not indicate or imply that the devices or equipment referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more, which will not be described in detail here.

[0083] like Figure 1 As shown, the system includes a single-layer acoustic holographic phase plate, a partitioned electrode array transducer 3 and a camera vision module.

[0084] It includes a partitioned electrode array transducer 3, which is placed underwater and below the single-layer acoustic holographic phase plate, and is used to transmit sound wave signals upward to the single-layer acoustic holographic phase plate; the upward direction can be vertically upward or obliquely upward.

[0085] It includes a single-layer acoustic holographic phase plate 4, which is placed underwater and above the partitioned electrode array transducer 3 and spaced apart, and arranged close to the water surface, for receiving the acoustic wave signal and feeding it back to the water surface to form a liquid surface pattern;

[0086] It includes a camera vision module 5, which is placed in the air domain and faces the water surface above the single-layer acoustic holographic phase plate 4, and is used to visually capture and process the deformation of the liquid surface pattern on the water surface, and analyze the liquid surface pattern to obtain information of the acoustic wave signal.

[0087] The camera vision module 5 does not need to be placed parallel to the underwater single-layer acoustic holographic phase plate 4 and the partitioned electrode array transducer 3. It can usually be placed at an angle so that it can capture the complete liquid surface pattern facing the water surface above the single-layer acoustic holographic phase plate 4.

[0088] In the specific implementation, the single-layer acoustic holographic phase plate 4 and the partitioned electrode array transducer 3 are both placed underwater, and the probe end faces of the single-layer acoustic holographic phase plate 4 and the partitioned electrode array transducer 3 are arranged in parallel with a certain distance axially along the propagation direction. The two work together to realize the holographic sound field reconstruction of the water-air interface and the deformation of the water surface ripples.

[0089] The specific implementation also includes an information transmitting point 1 and a switch control module 2. The information transmitting point 1 is electrically connected to the partitioned electrode array transducer 3 via the switch control module 2. The information transmitting point 1 transmits the original excitation signal, and the switch control module 2 controls the partitioned electrode array transducer 3 to emit an acoustic wave signal corresponding to the liquid surface pattern.

[0090] The partitioned electrode array transducer is used to stimulate and generate ultrasonic signals. The partitioned electrode array transducer 3 contains a piezoelectric device. The piezoelectric device uses a dicing machine to evenly and discretely divide the electrodes on one side of itself into multiple independent array elements. The electrodes on the other side maintain their integrity and remain a single electrode surface without any processing. All array elements are connected to an external switching circuit. The external switching system can independently control the gating / disconnection of each array element. Specifically, the switch circuit code controls the electrical connection and disconnection of each array element, thereby achieving dynamic coding and regulation of the incident sound wave distribution under a single electrical signal input. The incident sound field excited by the partitioned electrode array transducer is then incident on a single-layer acoustic holographic phase plate for spatial phase regulation, thereby subdividing the liquid surface pattern display into different positions for different displays.

[0091] Specific implementation such as Figure 2 As shown in FIG, a physical diagram and preparation process of the partitioned electrode transducer 3 with the ability to dynamically control the incident sound field provided by the present invention. Among them, the single-side electrode of the piezoelectric sheet of the partitioned electrode array transducer 3 is discretely separated into N×N independent units by a dicing machine, such as Figure 2 (a), by Figure 2 (b) The flexible circuit board independently leads out each electrode area and then connects to the switch control module 2 and the ultrasonic excitation signal in turn, and finally welds the flexible circuit board to the partitioned electrode. Figure 2 Furthermore, the switch control module 2 can be used to code and control the on / off of each discrete array element to achieve dynamic control of the incident sound field.

[0092] The single-layer acoustic holographic phase plate 4 is made of polymer using 3D printing, with one side having a concave-convex surface and the other side having a flat surface. Based on the three-medium theory, the thickness and frequency of the spatially distributed thickness units are matched, and the transmission phase delay difference between the two units (the larger and smaller units) is exactly equal to π.

[0093] In practice, a 3D-printed single-layer acoustic holographic phase plate features a spatial array of two thickness units, h1 and h2, resulting in a flat surface on one side and uneven surfaces on the other. Based on the three-medium theory, the two phase-modulating units, h1 and h2, have a phase difference of π in the transmitted sound field at an operating frequency of f, thus achieving spatially coded phase modulation of the incident sound field.

[0094] like Figure 3 As shown, the "seven-segment tube" pattern for water-air cross-domain communication provided by the present invention is as follows: Figure 3 (c) shows the "seven-segment tube" pattern being independently divided into seven patterns a to g. Based on the time-division multiplexing multi-plane iterative angular spectrum method, the electrode excitation areas corresponding to the seven patterns are designed, denoted as A1 to A7, each of which is an N×N 0 / 1 matrix, where N is the number of columns / rows of the partitioned electrodes.

[0095] based on Figure 3 , the partitioned electrode array transducer 3 and the single-layer acoustic holographic phase plate 4 are respectively located at z =0mm and z=l =50 mm, and set the "seven-segment tube" pattern to z=L =80 mm, and the sound pressure distribution P1 0 ~ P7 0 (n×n) are respectively as Figure 3 At the same time, the coded fusion phase distribution on the single-layer acoustic holographic phase plate 4 is initialized. φ b is an arbitrary value (n×n), and A1~A7 are also expanded to n×n matrices, where is the resolution of the target sound field, indicating the number of rows / columns of discrete sound wave data.

[0096] First, the forward propagation model is used to calculate the incident wave on the single-layer acoustic holographic phase plate 4 ( z=l =50 mm) incident sound field distribution: Fourier transform calculation z =0 plane sound field distribution p 0i ( x , y , z =0)= A i Spectrum distribution P0i ( k x , k y , z =0)=∫∫ p 0i ( x , y , z =0)d x d y ; and push the spectrum outward along the z-axis to the plane of the single-layer acoustic holographic phase plate 4 z = l= At the 50 mm incident side, the spectrum distribution is: P ’ i ( k x , k y , z = l ). And the single-layer acoustic holographic phase plate plane is obtained by inverse Fourier transform z = l The sound field distribution on the incident side is p i ’ ( x , y , z = l )=∫∫ P ’ i ( k x , k y , z = l )d k x d k y .

[0097] Next, based on the above seven incident sound field distributions p i ’ ( x , y , z = l ) and target sound field distribution P1 0 ~ P7 0 The fusion coding phase on the single-layer acoustic holographic phase plate is designed using the multi-plane iterative angular spectrum method. φ b The multi-plane iterative angular spectrum method includes two processes: forward propagation and back propagation. The specific steps are as follows:

[0098] S1: The forward propagation process is as follows: the single-layer acoustic holographic phase plate 4 plane z = l= The sound field distribution on the 50 mm transmission side can be expressed as: p i ’’ ( x , y , z = l )= p i ’ ( x , y , z = l )*e^( jφ b ). Also use Fourier transform to calculate its spectrum distribution: P i ’’ ( k x , k y , z = l )=∫∫ p i ’’ ( x , y , z = l )d x d y , and the spectrum is pushed outward along the z-axis to the target plane z = L= 80 mm, the spectrum distribution of the target plane is P i ’’’ ( k x , k y , z = L ), and use the inverse Fourier transform to calculate its sound field distribution: p i ’’’ ( x , y , z = L )=∫∫ P i ’’’ ( k x , k y , z = L )dk x d k y .

[0099] S2: After the forward propagation is completed, the target plane is respectively z = L Phase distribution on φ i ’’’ ( x,y , z = L )= arg ( p i ’’’ ( x , y , z = L ))Reserved, of which, arg () is the phase extraction function. Update the target plane z = L The sound field distribution on q i ’’’ ( x,y , z = L )=P i 0 *e^(j φ i ’’’ ( x,y , z = L )).

[0100] S3: The back propagation process is as follows: Calculate the target plane using Fourier transform z = L The spectrum distribution is Q i ’’’ ( k x , k y , z = L )=∫∫ q i ’’’ ( x,y , z = L )d x d y , and push the spectrum outward in the negative direction along the z axis to the plane of the single-layer acoustic holographic phase plate 4 z = l On the transmission side, its spectrum distribution is Qi ’’ ( k x , k y , z = l ). And the sound field distribution is calculated by inverse Fourier transform: q i ’’ ( k x , k y , z = l )=∫∫ Q i ’’ ( k x , k y , z = l )d k x d k y .

[0101] S4: Sound field distribution based on the incident side of the single-layer acoustic holographic phase plate 4 p i ’ ( x , y , z = l ) and the sound field distribution on the transmission side obtained by the reverse propagation process q i ’’ ( k x , k y , z = l ), the fusion phase distribution on the single-layer acoustic holographic phase plate 4 is calculated as: φ 0=∑ arg ( q i ’’ ( k x , k y , z = l )* conj ( p i ’ ( x , y , z = l))),in conj () is a conjugate function. φ 0 performs binarization operation and updates the binary phase distribution φ b =0 or π, when cos( φ 0)>0, φ b =0; when cos( φ 0)<=0, φ b =π.

[0102] After approximately 60 forward and backward propagation iterations, the coded fusion phase distribution on the single-layer acoustic holographic phase plate 4 is finally obtained. φ b .

[0103] like Figure 4 (a) and (b) are schematic diagrams of the three-dimensional and two-dimensional structures of the single-layer acoustic holographic phase plate 4. The single-layer acoustic holographic phase plate 4 includes two thickness coding units arranged in space, with thicknesses of h 1 and h 2 , and the following relationship is satisfied between the two: h 1 - h 2 =λ / 2; where λ= f / c is the wavelength of the ultrasonic wave. At this time, the two thickness units are fused according to the coding phase distribution φ b Arrange.

[0104] At the same time, if Figure 5 As shown, the seven sub-sections of the "seven-segment tube" are spatially combined to encrypt and represent 36 letters and numbers. At this time, the 36 "seven-segment tube" patterns correspond one-to-one to the 36 information of A to Z and 0 to 9.

[0105] It should be noted that there is no consistent pattern among the 36 reconstructed patterns after rotation or mirroring, so the placement of the air domain camera vision module 5 is not required to be high.

[0106] After the electrode partition array transducer 3 and the single-layer acoustic holographic phase plate 4 are designed, the electrode partition array transducer 3 and the single-layer acoustic holographic phase plate 4 are placed horizontally and underwater.

[0107] Next, combine Figure 6-Figure 9 The water-air cross-domain wireless acoustic communication technology based on dynamic acoustic holography in an embodiment of the present invention is described as follows:

[0108] based on Figure 6 As shown, cross-domain communication is performed using a vision module above the liquid surface. First, the activation and deactivation of each element in the electrode-zoned array transducer 3 are controlled by coding, generating different target incident sound fields. These incident sound fields are modulated by the single-layer acoustic holographic phase plate 4 during forward propagation and continue to propagate to the water-air interface, creating a target holographic sound field. This target holographic sound field, acting on the liquid surface due to the acoustic radiation force, produces different patterns. Next, a camera vision model 5 system is used above the liquid surface to capture the surface ripples.

[0109] Before the water-air cross-domain communication begins, a camera is first used to collect 36 "seven-segment tube" patterns from different angles and under different lighting conditions. After manual labeling, they are used as a training set for the convolutional neural network to train the neural network for "seven-segment tube" water surface ripple image recognition. After the training is completed, the neural network model can be used to decode and output the water surface ripple patterns captured in actual situations. The results are as follows: Figure 7 As shown, the characters '5', '4', '0', '1', and '9' can be read. Further, the underwater information real-time communication technology is described in combination with Examples 1 and 2: Example

[0110] like Figure 8 As shown, static cross-domain wireless acoustic communication of the letter "H" based on dynamic acoustic holography includes the following steps:

[0111] S1: Based on Figure 6 and Figure 8 , select the "seven-segment tube" pattern corresponding to the letter "H" and its 0 / 1 matrix electrode area distribution (8*8 matrix), and encode it into a 64-character binary data stream of "0100010011000".

[0112] S2: After the underwater signal transmitting point 1 wirelessly transmits the above-mentioned 64-character binary data stream to the switch control module 2 underwater, the switch control module 2 converts the 64-character data back into an 8*8 electrode mechanism area for controlling the connection / disconnection of each excitation array element of the partitioned electrode array transducer 3.

[0113] S3: The incident sound field generated by the excitation is as follows Figure 3 (b), and under the joint action of the single-layer acoustic holographic phase plate 4, a target "seven-segment tube" holographic acoustic field distribution is generated at the water-air interface, and based on the action of the acoustic radiation force, a corresponding liquid surface deformation is generated.

[0114] S4: After using the camera acquisition system 5 above the water surface to capture the water surface ripples in real time and efficiently, the water surface ripples are input into the trained neural network, and the water surface ripples are decoded through template matching to finally obtain the underwater "H" character information. Example

[0115] like Figure 9 As shown, dynamic cross-domain wireless acoustic communication of the "123HELLO" text data based on dynamic acoustic holography includes the following steps:

[0116] S1: Based on Figure 6 and Figure 9 According to the text data "123HELLO", the "seven-segment tube" pattern corresponding to 8 characters and its 8 0 / 1 matrix electrode area distribution (8*8 matrix) are determined, and the 8 8*8 matrix data are expanded into a 64-character binary data stream of "0100010011000", and directly spliced ​​into an 8*64 binary data stream in sequence.

[0117] S2: After the underwater signal transmitting point 1 wirelessly transmits the above-mentioned 8*64-character binary data stream to the switch control module 2 underwater, it converts the 8*64-character data into 8 8*8 electrode excitation areas at intervals of 64 characters, and controls the connection / disconnection of each array element of the partitioned array transducer 3 in turn, and excites in sequence at a certain frame rate to generate 8 incident sound field distributions.

[0118] S3: Under the combined effect of the dynamically changing incident sound field and the single-layer acoustic holographic phase plate 4, the holographic sound field distribution of eight targets "seven-segment tubes" will be dynamically reconstructed at a certain frame rate at the water-air interface, and based on the action of the acoustic radiation force, the corresponding dynamic liquid surface deformation will be generated.

[0119] S4: Use the camera acquisition system 5 above the water surface to capture the water surface ripples in real time and efficiently at the same frame rate, and input them into the trained neural network. The water surface ripples are decoded by template matching, and the real-time decoding finally obtains the underwater text information "123HELLO".

[0120] The above results show that through the joint work of dynamic acoustic holography and camera vision modules, real-time encrypted communication of underwater information can be achieved, which has good real-time performance and operability.

[0121] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0122] The embodiments of the present application are described in detail above. Specific examples are used in the present invention to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A cross-domain wireless acoustic communication method for a cross-domain wireless acoustic communication system, characterized by: The method adopts a cross-domain wireless acoustic communication system based on acoustic holography, wherein the cross-domain wireless acoustic communication system: It includes a partitioned electrode array transducer (3) placed under the liquid and used to transmit acoustic wave signals to the single-layer acoustic holographic phase plate; It comprises a single-layer acoustic holographic phase plate (4), which is placed under the liquid and above the partitioned electrode array transducer (3), and is arranged close to the liquid surface, and is used to receive the acoustic wave signal and feed it back to the liquid surface to form a liquid surface pattern; It includes a camera vision module (5) placed in the air domain and facing the liquid surface above the single-layer acoustic holographic phase plate (4), and is used to visually capture and process the liquid surface pattern on the liquid surface, and analyze the liquid surface pattern to obtain information of the acoustic wave signal; The method comprises: The partitioned electrode array transducer (3) is excited to emit an incident ultrasonic sound wave, which is then phase modulated after propagating to the single-layer acoustic holographic phase plate (4) and then continues to propagate forward to the interface between different medium domains. The interface between the different medium domains undergoes surface deformation under the action of the acoustic radiation force, and holographic sound field reconstruction is achieved on the interface. At the same time, the camera vision module (5) above the interface is used to visually capture, collect and decode the surface deformation of the interface, thereby directly extracting the acoustic wave information below the liquid surface and ultimately achieving end-to-end cross-domain wireless acoustic communication between devices below the liquid surface and above the liquid surface; The incident ultrasonic sound waves emitted by the partitioned electrode array transducer (3) act on the interface through the single-layer acoustic holographic phase plate (4) to form a surface deformation of a "seven-segment tube" pattern code. The "seven-segment tube" pattern code has a time-sharing multiplexing characteristic, specifically: The "seven-segment tube" pattern is an "8" character, with each edge segment of the "8" character as a sub-unit for coding. The coding relationship in the following table controls the display of all different sub-units, thereby correspondingly presenting different letters and numbers on the interface: A: Upper right vertical line B: Upper left and upper right vertical lines C: upper and lower horizontal lines D: Upper right vertical line + middle horizontal line E: Upper right and lower right vertical lines F: upper horizontal line + lower right vertical line G: Upper right and lower left vertical lines H: upper and lower horizontal lines + lower right vertical line I: upper, middle and lower horizontal lines J: Upper left, upper right, lower right vertical lines K: middle horizontal line + upper right and lower right vertical lines L: upper horizontal line + upper right and lower right vertical lines M: upper horizontal line + upper left and upper right vertical lines N: upper horizontal line + lower left and lower right vertical lines O: upper and middle horizontal lines + upper left and upper right vertical lines P: Upper left, upper right, lower left, lower right vertical lines Q: upper, middle, and lower horizontal lines + upper right vertical line R: upper right, lower left, lower right vertical lines S: upper and middle horizontal lines + upper right and lower right vertical lines T: Upper left and upper right vertical lines + middle and lower horizontal lines U: upper and middle horizontal lines + upper left and lower right vertical lines V: upper and lower horizontal lines + upper right and lower right vertical lines W: upper and lower horizontal lines + upper left and upper right vertical lines X: upper right, lower left, lower right vertical lines + lower horizontal line Y: upper and lower horizontal lines + upper right and lower left vertical lines Z: upper and middle horizontal lines + upper left, upper right, lower right vertical lines 0: upper, middle, and lower horizontal lines + upper right and lower left vertical lines 1: Top, middle, and bottom horizontal lines + top right and bottom right vertical lines 2: Top, middle, and bottom horizontal lines + top left and top right vertical lines 3: Upper horizontal line + upper left, upper right, lower left, lower right vertical lines 4: Middle horizontal line + upper left, upper right, lower left, lower right vertical lines 5: Upper and lower horizontal lines + upper left, upper right, and lower left vertical lines 6: Middle and lower horizontal lines + upper left, upper right, and lower left vertical lines 7: Upper and middle horizontal lines + upper left, upper right, lower left, and lower right vertical lines 8: Upper and lower horizontal lines + upper left, upper right, lower left, and lower right vertical lines 9: Top, middle, and bottom horizontal lines + top left, top right, bottom left, and bottom right vertical lines The above number consists of 36 characters, including letters A to Z and numbers 0 to 9.

2. The cross-domain wireless acoustic communication method according to claim 1, wherein: The partitioned electrode array transducer (3) emits different incident ultrasonic sound waves in sequence at different times, and the single-layer acoustic holographic phase plate (4) acts on the interface to form different surface deformations in sequence. The camera vision module (5) visually captures the surface deformation pattern of the interface in sequence to obtain a visual image, and performs image analysis processing on the visual image captured in sequence to obtain dynamic information.

3. The cross-domain wireless acoustic communication method according to claim 1, wherein: The fixed single-layer acoustic holographic phase plate integrates the fused phase information corresponding to the "seven-segment tube" pattern into its phase distribution, and each subunit of the "seven-segment tube" pattern is time-selected by the partitioned electrode array transducer.

4. The cross-domain wireless acoustic communication method according to claim 1, wherein: After the camera vision module (5) visually captures an image of the liquid surface pattern on the water surface, it uses a convolutional neural network model to perform recognition processing on the image to obtain the "seven-segment tube" pattern information therein.

5. The cross-domain wireless acoustic communication method according to claim 1, wherein: The single-layer acoustic holographic phase plate (4) and the probe end surface of the partitioned electrode array transducer (3) are arranged in parallel at an axial distance along the propagation direction.

6. The cross-domain wireless acoustic communication method according to claim 1, wherein: The device also includes an information transmitting point (1) and a switch control module (2). The information transmitting point (1) is electrically connected to the partition electrode array transducer (3) via the switch control module (2). The information transmitting point (1) transmits an original excitation signal, and the partition electrode array transducer (3) is controlled by the switch control module (2) to emit an acoustic wave signal corresponding to a liquid surface pattern.

7. The cross-domain wireless acoustic communication method according to claim 1, wherein: The partitioned electrode array transducer (3) has a piezoelectric device inside. The piezoelectric device uses a dicing machine to evenly and discretely divide one side of the electrode into a plurality of independent array elements. All array elements are externally connected to a switch circuit. The switch circuit code controls the electrical connection and disconnection of each array element, thereby realizing dynamic coding control of the incident sound wave distribution under a single-channel electrical signal input, thereby making the liquid surface pattern display subdivided into different positions for different displays.

8. The cross-domain wireless acoustic communication method according to claim 1, wherein: The single-layer acoustic holographic phase plate (4) is made of polymer using a 3D printing method, with one side having a concave-convex surface and the other side having a flat surface.

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