26 results about "Acoustic holography" patented technology

The invention discloses a honeycomb topology microphone array for equivalent source method near-field acoustical holography, which is characterized in that according to the geometrical shape and geometrical parameters of the honeycomb topology microphone array, the space coordinates of N array lattice points in one-to-one correspondence with N microphones are calculated and obtained based on a honeycomb lattice point generation algorithm; further obtaining a cellular topology microphone array with N array lattice points; measuring by using the cellular topology microphone array to obtain sound field measurement data; and further utilizing the sound field measurement data to obtain a sound field distribution result of a reconstruction surface through an equivalent source method, and completing the design of the honeycomb topology microphone array for the equivalent source method near-field acoustical holography. According to the method, the spatial distribution of the array is optimized, the condition number of the transfer matrix is remarkably reduced while the coverage uniformity of the sound field is ensured, and then the stability and precision of sound field reconstruction based on the equivalent source method are improved.

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.

The application discloses a kind of fast generation method and system of transcranial focused acoustic holographic lens based on deep learning, uses k-wave toolbox in Matlab, utilizes time reversal method to set the focus point as sound source, captures the phase at the plane of ultrasonic transducer, to design acoustic holographic lens;With the position of preset focus point and the holographic lens designed as data set training U-net network, the input of the U-net network is the position of preset focus point, and the output is the holographic lens designed;Set target focus point, input the U-net network trained, and obtain the holographic lens corresponding to the target focus point from the U-net network output trained;Based on the U-net network output holographic lens design, the holographic lens is manufactured by 3D printing.Based on the framework of deep learning, fast and accurate acoustic holographic lens is generated, and the problem that the acoustic holographic lens is consumed too large computing resources in the process of transcranial focusing by acoustic holographic lens is solved.

The invention discloses a wireless cross-domain acoustic communication system and method based on acoustical holography. The acoustical holography device used for cross-domain acoustic communication is composed of a single-layer acoustical holography phase plate, an array transducer and a camera vision module, each array element of the array transducer has a connected state and a non-connected state, and after a communication coding signal transmitted in water is received, the single-layer acoustical holography phase plate is connected with the camera vision module through the single-layer acoustical holography phase plate. The transducer array elements at the corresponding positions can be sequentially gated according to the sequence, dynamic regulation and control of an incident sound field are realized, the incident sound field passes through the single-layer holographic phase plate and is subjected to phase modulation to be transmitted to a water-air interface, the interface is deformed under the action of acoustic radiation force, and the camera vision module is used for capturing, analyzing and decoding the water surface deformation condition, so that the water surface deformation condition is obtained. And information wireless receiving across a water-air interface is completed. According to the invention, underwater information can be directly transmitted to the air, the equipment is simple, the requirement on the relative position of transmitting-receiving equipment is not strict, and the device is suitable for a liquid environment with any temperature, salinity and density.

The invention relates to the technical field of acoustic imaging, in particular to a multiplexing acoustic holographic imaging device and method based on a mixed porous Helmholtz resonator metasurface. The metasurface antenna comprises an emission source, a receiving end and a metasurface, the emission source is a planar acoustic wave transducer and is used for emitting planar acoustic waves under working frequency; the receiving end is a microphone probe and is used for receiving sound signals in a sound field and carrying out sound field scanning and imaging; the metasurface is an array composed of a plurality of unit structures. Each unit structure is composed of four subunits which respectively correspond to four working frequencies; each subunit is a Helmholtz resonator filled with a porous medium; the emission source emits plane sound waves, stable sound field amplitude distribution is formed within a specific range of a metasurface reflection field through metasurface regular reflection, and the distribution corresponds to an acoustic holographic image. Compared with a traditional reflective multiplexing acoustical holography metasurface, the structure of the acoustic holography metasurface has the advantages that the manufacturing difficulty is remarkably reduced, and a complex optimizing process is also avoided through decoupling modulation of reflected sound waves.

The invention discloses a cross-water and cross-air holographic projection system and method based on an amplitude-phase decoupling acoustic artificial interface, arbitrary and combined modulation is performed on the amplitude and phase of sound waves, in a cross-medium scene, dual modulation can better compensate energy loss and phase distortion at the interface, and the system and the method have good application prospects. Therefore, more accurate wavefront reconstruction and a sound field mode with higher resolution are realized; according to the acoustic metamaterial unit based on the UV resin skeleton-air channel binary composite material, complete control over the amplitude and phase of transmission sound waves is achieved at the specific frequency; an acoustic artificial interface located at the junction of media is constructed by utilizing a super-structure unit and serves as an acoustic projector, cross-medium projection of a holographic image and cross-medium control of particles are achieved, and a new high-fidelity cross-medium acoustical holography mechanism is constructed.

The present invention discloses a method, system, device and storage medium for constructing a three-dimensional sound field with high precision, which can be adapted to any acoustic phased array or metamaterial, including geometric features such as the scale, quantity, position of the transmitting units and the acoustic radiation performance, and is optimized for different types of transmitting units; uses the acoustic holography algorithm, through iterative optimization, makes full use of the performance of the phased array or metamaterial to construct an arbitrary three-dimensional sound field distribution with high precision, such as constructing spatial multi-beams, multi-foci and the distribution of arbitrary sound intensities in space, generating arbitrary acoustic images, etc.; realizes high-precision control of sound energy, including the accuracy of spatial position and distribution intensity, and improves the application experience of acoustic means in the fields of consumer electronics, biomedical engineering and underwater acoustic detection, etc. This acoustic holography algorithm is calculated based on a clear physical process, uses convolution or frequency-domain calculation in the process of calculating sound propagation, has a fast calculation speed, can be calculated in real time, and is used for constructing a real-time three-dimensional sound field distribution with high precision.

The invention discloses an elevator noise source detection and identification method and device. The method comprises the following steps that acoustic signals of the car top, the car top shaft space, the car bottom and the car bottom shaft space are collected, and vibration signals generated by a traction machine, a guide rail and a car in the elevator running process are collected; estimating time delay between acoustic signals through a generalized cross-correlation algorithm, establishing a nonlinear equation set about a sound source position, and solving to obtain a sound source estimation position; obtaining a sound source position through a beam forming algorithm in combination with the sound source estimation position so as to determine a noise source area; if the position of the sound source points to the interior of the car frame or the interior of the traction machine, the complex sound pressure of an area adjacent to the position of the sound source is measured, and sound field visualization is achieved through near-field acoustical holography so as to locate a noise source area; and judging whether the noise source is an impact sound source or a wind noise source on the same time axis according to the acoustic signal and vibration signal peak conditions of the noise source region. According to the technical scheme, the elevator noise detection efficiency is improved.

The present technology provides methods, apparatuses, and systems for high-speed acoustic levitation, for example, for high-speed acoustic holography or other applications. A novel technology is presented that enables high-speed multi-point levitation even in the presence of any sound-scattering surface and demonstrates a process that works well in the presence of any physical object. Embodiments provide a simplified approach for determining the location of traps within a working volume, which may sometimes also be referred to as an acoustic volume or an acoustic chamber. Further, embodiments provide an approach for determining the location of traps by determining the contribution from the scattering surface within the working volume and the contribution from the target object within the working volume.

The application discloses a high-security double-encryption information communication method based on reconfigurable acoustic holography. The correct information image and the pseudo information image are mixed and then input into a dynamic acoustic holographic neural network to output ciphertext information and an electronic key; a reconfigurable acoustic holographic phase plate carrying the ciphertext information is prepared; based on distance position information, partitioned electrically encoded ultrasonic transducers and the reconfigurable acoustic holographic phase plate are placed; an electrically encoded sequence is input into the transducer; the correct information image is decoded and reconstructed and then visualized on a sound field reconstruction visualization plane; and the reconfigurable acoustic holographic phase plate can be restored for the next encryption information communication. The method can mix the correct information into multiple groups of pseudo information to improve information security, and can encode the electronic key in multiple dimensions to further improve information decoding difficulty, and has a read-once-burn-after feature, so that secondary information leakage can be fundamentally prevented; the method is simple in equipment and difficult in information decryption, and is suitable for high-throughput transmission of text information.

The application discloses a kind of based on the acoustic holography technology's microparticle composite material sound auxiliary manufacturing device and method.Acoustic control module and mixed liquid container lifting mechanism are fixed in water tank inner bottom surface, mixed liquid container lifting mechanism is equipped with mixed liquid container, for accommodating mixed liquid containing microparticle, acoustic control module is set in the lower side of mixed liquid container, for projecting ultrasonic wave to mixed liquid container, to control the spatial arrangement of microparticle in mixed liquid;Layer-by-layer solidification platform lifting mechanism is set to one side of water tank, layer-by-layer solidification platform is installed on layer-by-layer solidification platform lifting mechanism, layer-by-layer solidification platform is set opposite to mixed liquid container, solidification light source is set to mixed liquid container, for the light curing of mixed liquid in mixed liquid container.The application effectively combines acoustic holography technology and 3D printing technology, can arrange microparticle in precursor liquid in the process of material layer-by-layer solidification, and manufacture composite material with arbitrary three-dimensional structured microparticle arrangement.

The present invention discloses a depth dynamic focusing acoustic lens device and method based on cascaded acoustic holography. It includes a dynamic focusing acoustic lens cascaded structure mainly composed of two acoustic holographic phase plates cascaded axially in a liquid-filled cavity. One acoustic holographic phase plate remains fixed, and the other acoustic holographic phase plate moves freely. The dynamic movement of the focus along the depth is achieved by moving axially and rotating circumferentially. Both phase holographic plates are composed of a tightly arrayed plurality of microstructural units with different thicknesses. The two sides are respectively concave-convex and flat, and both the concave-convex planes face the inside of the cavity. The present invention can simply and conveniently achieve dynamic acoustic energy focusing at multiple positions, thereby realizing detection and imaging on different planes of the object to be measured, greatly improving the detection efficiency. When in use, it can be directly and closely attached to the surface of a conventional ultrasonic transducer and the component to be measured, and different plane target scanning and medical treatment can be achieved through simple movement and rotation between the holographic plate components in the structure.

The invention discloses a frequency-angular momentum multiplexing acoustical holography method based on an acoustic metasurface, and the method comprises the steps: determining the transmission amplitude phase distribution of the acoustic metasurface at each working frequency according to the frequency and orbital angular momentum order of each vortex acoustic beam and the projection position corresponding to each acoustic beam at a receiving end, and carrying out the spatial discretization and numerical discretization, according to the method, parameters of each metamaterial unit of the acoustic metasurface are determined, the acoustic metasurface with frequency selectivity and angular momentum selectivity is obtained, the acoustic metasurface achieves accurate decoupling regulation and control on amplitudes and phases of sound fields with different frequencies, and acoustic holographic projection with the frequency selectivity and the angular momentum selectivity at the same time is achieved. According to the method, the frequency multiplexing technology and the angular momentum multiplexing technology are combined, the information containing capacity of the acoustic holographic technology is greatly expanded, the flexibility of the acoustic holographic technology is enhanced, and the blank of related fields is filled.

The invention relates to the technical field of sound power measurement, and discloses a device and a method for testing the sound power of a radial transducer of a circular tube, the device for testing the sound power of the radial transducer of the circular tube comprises a measuring device, an ADC module and a digital processing module, and the measuring device and the ADC module form a signal acquisition module; according to the device disclosed by the invention, a measurement environment with a controllable acoustic boundary is formed by constructing a closed acoustic cavity and combining a sound absorption material and degassing water, echo reflection is effectively inhibited, and the device does not need to depend on facilities such as a large-scale anechoic pool, can be used in a limited space such as a common laboratory or a detection site, and is high in practicability; the transducer positioning mechanism can realize precise positioning and fixing of the circular tube transducer, so that the consistency of a measurement reference is ensured, and the measurement precision is improved; the array type sensors are symmetrically arranged, and the distance can be dynamically adjusted according to the working frequency of the transducer to be detected, so that the spatial sampling requirement of near-field acoustical holography is met, and sound pressure signals can be accurately acquired.

The invention discloses an acoustic metamaterial optimization deployment method based on sound field diagnosis and machine learning. The method comprises the following steps: S1, acquiring and preprocessing multi-source sound field data; s2, three-dimensional sound field feature extraction and reconstruction; s3, sound field state diagnosis and classification; s4, meta-material deployment scheme optimization based on transfer learning: based on the sound field spatial features and the sound field state labels, domain adaptation is performed on strategy library data and current sound field features by using a joint distribution adaptation method, and meta-material layout schemes adapted to the sound field state labels are generated through an optimization algorithm; and S5, performing dynamic deployment and feedback optimization. By deploying the sensor array and fusing the near-field acoustical holography / beam forming technology, three-dimensional space distribution (amplitude and phase) of a sound field can be reconstructed, deep features including spatial textures are extracted, the limitation of traditional single-point or simple array measurement is broken through, and the measurement accuracy is improved. And a comprehensive and accurate physical field state information basis is provided for subsequent intelligent decision making.

The invention discloses a dynamic mirror boundary acoustical holography testing device and method, and belongs to the technical field of near-field acoustical holography test.The dynamic mirror boundary acoustical holography testing device comprises a translation track, a first driving mechanism is arranged on one side of the translation track, a testing mechanism is arranged on the other side of the translation track, the first driving mechanism is connected with a first base, and a second driving mechanism is installed on the first base; the second driving mechanism is connected with the second base. The top of the second base is connected with the rigid plate. According to the dynamic mirror image boundary acoustical holography test device and method, under the condition that the number of sensors is not increased, the test information amount is increased, and the sound field reconstruction precision is improved; fixed measuring points are combined with rigid boundary movement, the number of all sensors is increased according to rigid surface single-time movement sound pressure data, and the measuring time is shortened compared with point-by-point movement of the sensors; the synchronization and calibration difficulty of multiple sensors is reduced by depending on a small number of fixed sound pressure sensors and controllable rigid boundaries; a position-adjustable mirror image source point is introduced by using a mirror image principle, and is not limited by a holographic aperture requirement.

The present invention discloses a method and device for optimizing a three-dimensional microphone array for multi-target collaboration in sound field measurement, and relates to the technical field of microphone array signal measurement. The method comprises: generating an initial array element group of a microphone array through an improved Sine chaotic mapping; constructing a hybrid fitness function to calculate the fitness of the microphone array to the sound source positioning and sound field reconstruction algorithm; and obtaining an optimized three-dimensional microphone array for multi-target collaboration in sound field measurement according to the hybrid fitness function using the whale elite optimization algorithm. The present invention can solve the problem that the initial array element group cannot be evenly distributed in the entire space, improve the fitness of the microphone array for the sound source positioning and sound field reconstruction algorithm, and realize the optimal distribution of the three-dimensional microphone array elements and the excitation weights of the microphone array elements. Through the fusion of the above three parts, a three-dimensional microphone array with high fitness for beamforming and acoustic holography algorithms is finally optimized, which can effectively improve the output response characteristics of the microphone array.

The present techniques provide a method, apparatus and system for high-speed acoustic levitation, for example high-speed acoustic holography or other applications. A novel technique is presented that allows high-speed multi-point levitation even in the presence of arbitrary sound-scattering surfaces and demonstrates a process that works in the presence of any physical object. Embodiments provide a simplified approach for determining locations of traps in a working volume which may also be termed an acoustic volume or acoustic chamber. Moreover, embodiments provide an approach for determining the location of traps by determining a contribution of a scattering surface in the working volume and a contribution from a target object in the working volume.

The invention discloses a near-field acoustical holography optimization method based on a compressed sensing equivalent source. The near-field acoustical holography optimization method comprises the following steps of 1) performing equivalent processing on a space sound field; step 2), selecting the position and size of a holographic measurement surface in a potential sound source near field, performing equidistant grid division on the holographic surface, and determining a sampling strategy; 3) selecting a certain number of measurement points on the holographic measurement surface in a random manner, constructing a near-field acoustic holographic model based on the compressed sensing equivalent source, and solving an initial sparse solution of the source intensity of the equivalent source by using L1 regularization according to the sound pressure at the measurement points randomly selected in the holographic surface; according to the method, the sparsity of an equivalent source intensity solution can be further improved, the influence of a pseudo source is effectively restrained, the convergence speed of iterative calculation can be increased, and the calculation efficiency is improved.

The present invention discloses a method for identifying and repairing invalid data in near-field acoustic holography based on sparse modal expansion. First, the acoustic radiation modal expansion formula of the measured data of the holographic surface is obtained by performing acoustic radiation modal expansion on the measured data; the acoustic radiation modal expansion formula is probabilistically described by using the Gaussian distribution assumption imposed on the observation noise; then, by applying Gaussian and two-point distribution priors to each modal coefficient and the measured data, the measurement point number and modal coefficient corresponding to the invalid data are obtained by Bayesian learning; the data at the measurement point number corresponding to the invalid data is reconstructed using the modal coefficient and replaces the original invalid data to obtain repaired data; the repaired data is input into the near-field acoustic holographic reconstruction algorithm to obtain the sound field reconstruction result of the reconstructed surface. As a pre-processing method for near-field acoustic holography technology, the present invention is not limited to real sound sources and sound field types, and can realize the identification and repair of invalid data within a large range of invalid data proportions.

The invention relates to the technical field of underwater acoustic sensor parameter testing, in particular to a hydrophone array design method for acoustic array mutual radiation impedance near-field acoustical holography measurement, the hydrophone array design method is determined through theoretical modeling, design parameters of a hydrophone array are obtained, and the problems of the array form, the aperture, the array element spacing and the like of the hydrophone array are solved. According to the method, the problems about selection of geometric parameters such as the array frame and the like are solved, meanwhile, process design parameters of the hydrophone array are given, the needed array design parameters and process requirements are provided for research and development of the near-field measurement hydrophone array, the reliability and feasibility of research and development of the hydrophone array are improved, and meanwhile, the accuracy of near-field sound field information acquisition is also improved.

The present invention discloses a wireless multi-channel parallel communication method, device and equipment based on acoustic holography. A spatial multi-focus for communication is constructed through an acoustic holographic transmitting base station. After the signal is sent, it can only be received at the focus position, realizing end-to-end communication. This end-to-end communication has strong confidentiality. The encryption is based on the physical process of sound propagation. The effective signal can only be received at the focus. The spacing between its spatial multi-focus can be very small. By applying 40kHz ultrasound in the air and cooperating with acoustic holography technology, complete decoupling of the space within 3cm can be achieved. That is, two receiving devices can receive signals independently even if the distance between them is less than 3cm, without being affected by other channels, realizing high-density spatial multiplexing; or realizing multi-channel reception of small devices, realizing high-speed communication, and realizing high-density information transmission. It is particularly suitable for use in electromagnetically sensitive situations and occasions where electromagnetic waves are difficult to propagate.

The application discloses a statistical optimal near-field acoustic holography method based on non-uniform sampling, relates to the technical field of near-field acoustic holography, and overcomes the problems of large error, high cost and low precision of the existing statistical optimal near-field acoustic holography method based on uniform sampling. The method comprises the following steps: step one, non-uniform sampling of a holographic surface; step two, non-uniform sampling in the wave number domain based on the sampling in the step one; and step three, selection of a regularization parameter by means of the L curve method based on the sampling in the step two, so as to realize the statistical optimal near-field acoustic holography method based on non-uniform sampling. The distribution of sampling points of the holographic surface and the wave number domain is set by means of the non-uniform sampling mode, compared with the case of uniform sampling, the method can improve the reconstruction precision, reduce the cost and time of measurement, effectively reduce the number of measurement points and the matrix dimension while ensuring the reconstruction precision, and the sampling method is simple and easy to set, and therefore, the method is more suitable for practical engineering applications.

The application discloses a kind of for super-long high-resolution acoustic beam focusing acoustic hologram generation method, comprising: the source plane phase of the M target surfaces of the M focal points of the jth iteration is determined when the jth iteration;M focal points of the jth iteration are numbered, and acoustic holographic lens is generated based on numbering, and the mask plate of target surface is generated according to acoustic holographic lens;The jth coefficient is generated, and the jth global sound source phase is generated according to the jth coefficient, mask plate and source plane phase;Whether the jth global sound source phase and the amplitude of target surface satisfy the condition based on the degree of approach of the jth M focal points of sound pressure amplitude;If yes, acoustic hologram is generated according to the jth global sound source phase;Otherwise, the spacing of the M focal points of the jth iteration is adjusted, the M focal points of the jth optimization are obtained and the j+1th iteration is carried out until acoustic hologram is generated.The application can form super-long distance ultrasonic focusing under the premise of ensuring the diameter of small acoustic beam.

Method for in-situ measuring sound impedance of half-space boundary surface by single-layer microphone array, comprising: 1. arranging a sound source and a microphone array on one side of the half-space of the boundary for acoustic pressure holographic measurement; 2. establishing a mathematical model of the sound field in the half-space on one side of the boundary; 3. determining the optimal number of expansion terms of the basis function; 4. establishing a mathematical relationship between the holographic measurement acoustic pressure and the acoustic pressure on the boundary surface to reconstruct the acoustic pressure distribution on the boundary surface; 5. establishing a mathematical relationship between the holographic measurement acoustic pressure and the normal particle velocity of the boundary surface medium to reconstruct the normal particle velocity distribution of the boundary particles; 6. calculating the sound impedance rate of the boundary surface by using the reconstructed acoustic pressure and normal particle velocity. The present invention is based on near-field acoustic holography combined with in-situ acquisition of near-field acoustic pressure information of the physical boundary by a microphone array, realizing in-situ measurement and calculation of the sound impedance of the boundary surface, so that it is no longer necessary to rely on standard impedance measurement equipment and measurement environment to implement the measurement of the sound impedance of the boundary material sample.

A method for enhancing and reducing interference of a radiation sound field of a gas turbine is disclosed, in which a low-high pressure rotor of a gas turbine test bench is taken as a research object to simulate structural noise of the gas turbine; a sound pressure sensor is arranged to form a plane measurement surface to measure holographic sound pressure data; an equivalent wave model is solved based on the holographic sound pressure data and a sound source structure; a wave function radiation position is obtained according to position coordinates of a to-be-interpolated point; a statistical optimal near-field acoustic holography is used to expand a wave function matrix of an interpolation surface element to obtain a transfer matrix containing measurement points and interpolation points; interpolation data is obtained by in-situ reconstruction of a sound field by using the holographic sound pressure data and the transfer matrix, so that sound field data enhancement is realized.