Patents
Literature
Patsnap Eureka AI that helps you search prior art, draft patents, and assess FTO risks, powered by patent and scientific literature data.

882 results about "Acoustic speed" patented technology

The velocity at which a small disturbance will propagate through the medium is called Acoustic Velocity or Speed of Sound. The acoustic velocity is related to the change in pressure and density of the substance and can be expressed as. c = (dp / dρ) 1/2 (1) where. c = speed of sound (m/s, ft/s)

Intelligent bolt tightening control method and system based on axial force measurement

The invention relates to the technical field of bolt tightening, and provides an intelligent bolt tightening control method and system based on axial force measurement. Comprising the steps of collecting bolt identification and process parameter data, collecting temperature measurement data, and obtaining sound velocity compensation parameters and elastic modulus compensation parameters. And zero-load preloading data are collected and processed to generate zero-load baseline data, and a self-calibration model is obtained. Axial force data and ultrasonic echo data are collected, and an axial force fusion estimation result is obtained. And comparing an axial force fusion estimation result with target axial force data. And when in the target interval, fine twisting control is carried out based on model predictive control and a micro-stepping strategy, and the controllable damping unit is driven to carry out energy absorption and stopping. And acquiring an axial force fusion estimation result when the target axial force is reached, processing the data in the holding stage to obtain an axial force rebound check result, and if the axial force rebound check result exceeds the limit, performing secondary twisting control. According to the scheme, refinement and traceability of the bolt tightening process are achieved.
Owner:CHANGSHA BIAONENG INFORMATION TECH CO LTD

Underwater acoustic sensor network node positioning error correction method combined with acoustic velocity inversion

An underwater acoustic sensor network node positioning error correction method combined with acoustic velocity inversion, which method relates to the technical field of acoustic velocity inversion. The method comprises: deploying an acoustic source point and underwater acoustic sensor nodes which are at fixed positions, the underwater acoustic sensor nodes collecting acoustic velocity data sent by means of the acoustic source point, and by means of acoustic velocity data at different underwater acoustic sensor nodes, using an acoustic velocity field inversion algorithm to construct an acoustic velocity field model; collecting real-time acoustic velocity data at the different underwater acoustic sensor nodes, and obtaining acoustic velocity characteristic information at the different underwater acoustic sensor nodes and water characteristic information at the different underwater acoustic sensor nodes; performing comprehensive analysis on the acoustic velocity characteristic information and the water characteristic information, and evaluating the positioning accuracy of the acoustic velocity field model in respect of the underwater acoustic sensor nodes; and comparing quantized positioning accuracy results for the underwater acoustic sensor nodes with a preset threshold, and when there is a relatively large error in the positioning accuracy, generating an error signal. The method is conducive to improving the precision of underwater acoustic wave propagation and the accuracy of underwater acoustic sensor network node positioning, and evaluating the positioning accuracy of an acoustic velocity field model in respect of underwater acoustic sensor nodes.
Owner:CHINA UNIV OF PETROLEUM (EAST CHINA)

Multimode signal fusion and adaptive processing ultrasonic flowmeter and measuring method

The invention relates to the technical field of fluid measurement, in particular to a multimode signal fusion and self-adaptive processing ultrasonic flowmeter and a measuring method. The multimode signal fusion and self-adaptive processing ultrasonic flowmeter comprises an ultrasonic transducer, a signal generation driving module, a signal receiving and conditioning module, a control module, a signal processing module, a signal quality evaluation module and a sound velocity calculation and compensation module. According to the method, the time difference method and Doppler method signals are fused, the self-adaptive processing strategy is adopted to improve the measurement precision of the low-flow-velocity fluid and the impurity-containing fluid, the measurement precision of the low-flow-velocity fluid can be remarkably improved, the adaptability to complex fluid is enhanced, the overall measurement reliability is improved, the Doppler method precision is optimized, and the intelligent degree is high.
Owner:TIANDI CHANGZHOU AUTOMATION +1

Ocean engineering surveying and mapping terrain correction method based on multi-beam sounding

The invention relates to the technical field of ocean engineering surveying and mapping, and particularly provides an ocean engineering surveying and mapping terrain correction method based on multi-beam sounding. The method comprises the following steps: constructing a tremor-sound velocity coupling model through multi-source data synchronous acquisition, and generating a sound velocity dynamic correction term; fusing the static sound velocity profile, the internal wave disturbance term and the sound velocity correction term, and establishing a time-shifting sound velocity field of spatio-temporal evolution; realizing dynamic space homing calculation through a double-shaft decoupling rotation matrix based on a hull attitude and a time shifting sound velocity field; tunnel effect noise is suppressed by adopting an airspace adaptive filtering technology; the terrain deformation rate is calculated in combination with continuous cycle data, and a deformation threshold value is dynamically set through soil mechanical parameters to trigger graded safety early warning; and outputting the high-precision three-dimensional terrain model without the sound velocity error and the noise interference. According to the method, the problems of geological activity interference compensation deficiency, tunnel effect noise suppression insufficiency, large dynamic environment homing error and the like in traditional surveying and mapping are solved, and the reliability of complex sea area topographic survey is remarkably improved.
Owner:WEIHAI DADI ENGINEERING SURVEYING & MAPPING CO LTD

Submarine tunnel damage intelligent monitoring and identification method based on acousto-optic cooperative perception

The invention relates to the field of civil engineering structure health monitoring, in particular to a subsea tunnel damage intelligent monitoring and identification method based on acousto-optic collaborative perception. The method sequentially comprises the steps of deploying a three-dimensional acousto-optic sensing network, actively detecting sound waves, reconstructing a local sound velocity distribution cloud picture, identifying a sound velocity abnormal region, performing optical fiber response focusing sampling and establishing an intelligent damage diagnosis model. According to the method, the three-dimensional acoustic array and the distributed optical fiber grid are simultaneously deployed in the subsea tunnel structure, functional complementation is realized between the three-dimensional acoustic array and the distributed optical fiber grid, seamless cooperative sensing of crack coarse positioning and strain fine positioning is further realized, acoustic active detection, trigger type optical fiber high-frequency sampling and a temperature-strain decoupling algorithm are adopted, and the positioning precision of the subsea tunnel structure is improved. Seawater noise and thermal expansion interference are effectively eliminated, 'dry cracks' and'water seepage cracks' are accurately distinguished, real-time monitoring is carried out on a subsea tunnel structure, whole-process identification of micro-damage-expansion-failure is achieved, and an active early warning mechanism is established.
Owner:SANYA SCI & EDUCATION INNOVATION PARK WUHAN UNIV OF TECH

Method for measuring residual stress of metal component

The invention relates to the technical field of material mechanical property testing, in particular to a method for measuring residual stress of a metal component. According to the technical scheme, the method for measuring the residual stress of the metal component comprises a working process for measuring the residual stress of the metal component; according to the method, a technical path of multi-modal data assimilation is adopted, and a mechanical release mechanism of a drilling method and an ultrasonic stress measurement technology are deeply fused to calibrate and correct mass sound velocity data obtained by carrying out rapid ultrasonic scanning on the whole component on site, so that the precise measurement of the residual stress state of the metal component is realized, and the measurement precision is improved. According to the method, data authority and high credibility of a drilling method in a key area are reserved, the advantages of high efficiency and wide coverage of full-field measurement of an ultrasonic method are brought into full play, and efficient and accurate stress information is provided on the premise that components are not excessively damaged.
Owner:AVIC METAL MATERIAL PHYSICAL & CHEM TESTING TECH CO LTD

System for improving positioning precision under complex underwater acoustic channel and optimization method

The invention provides a system for improving positioning precision under a complex underwater acoustic channel and an optimization method, and relates to the field of underwater positioning. The system for improving the positioning precision under the complex underwater acoustic channel comprises a time delay estimation module, a sound velocity profile data module, a sound ray correction module, a slope distance value precision module and a precision improvement module, and the time delay estimation module is mainly used for obtaining more accurate time delay data; the sound velocity profile data module is mainly used for acquiring sound velocity profile data of a positioning area. According to the method, a real sound ray path is estimated by using a sound ray correction method, measurement errors of bubbles in water, sound velocity change and position and propagation time are considered, the positioning precision is further improved, and the comprehensive optimization method enables the system to accurately reflect the real position of a target in a complex underwater environment, so that the positioning accuracy is improved. The overall performance of underwater target positioning is remarkably improved, and the actual requirement of high-precision positioning is met.
Owner:HARBIN ENG UNIV

Method for carrying out nondestructive flaw detection on casting by using ultrasonic waves and flaw detection system

The invention relates to the technical field of metal ultrasonic detection, and discloses a method for performing nondestructive flaw detection on a casting by using ultrasonic waves and a flaw detection system.The method comprises the following steps that rapid modeling and acoustic reference calibration are performed on equipment and a workpiece, and a unified coordinate system, a sound velocity delay reference and an optimal sound beam path are obtained; acquiring and caching multi-view ultrasonic echoes in real time to obtain a high-integrity original data stream; implementing adaptive noise diffusion based on the data stream, and constructing a diffusion data stack matched with scattering characteristics; performing scattering compensation inverse diffusion and super-resolution fusion on the diffusion stack to obtain a high-resolution purified echo image; performing closed-loop regulation and control on image quality indexes, and optimizing scanning parameters in real time; and combining the optimized image and scanning parameters, and adopting a segmentation network and online increment fine tuning to realize defect identification and automatic grading. The system has high resolution, real-time performance and self-adaptive closed-loop control, and the reliability and the accuracy of casting defect detection are remarkably improved.
Owner:ZHEJIANG GANGHANG HEAVY IND MASCH CO LTD

Hydropower station diversion tunnel longitudinal crack depth detection method

The invention discloses a hydropower station diversion tunnel longitudinal crack depth detection method, which comprises the following steps: arranging ultrasonic measuring points above and below a diversion tunnel longitudinal crack to obtain a reinforced concrete sound velocity representative value; arranging ultrasonic measuring points within the length range of the crack; performing ultrasonic detection, and judging the depth of the crack through ultrasonic waves; adjusting the position of the ultrasonic measuring point according to the depth of the fracture until the ultrasonic shape is in a suitable state; and calculating the depth of each detection point of the longitudinal crack. According to the technical scheme, by means of the method for detecting the longitudinal crack depth of the reinforced concrete in the diversion tunnel of the hydropower station through the ultrasonic waves, crack depth detection and calculation of the circular tunnel are completed, and in order to judge the development condition and the stability state of the crack, the crack depth can be regularly detected in the overhaul period of a hydropower station generator set; therefore, monitoring of longitudinal crack expansion and extension is realized.
Owner:CHINA POWER CONSRTUCTION GRP GUIYANG SURVEY & DESIGN INST CO LTD

Double-frequency anti-interference ultrasonic water meter and metering method thereof

The invention discloses a double-frequency anti-interference ultrasonic water meter and a metering method thereof, and relates to the technical field of fluid metering. A 500kHz sound velocity reference channel is constructed in a self-transmitting and self-receiving mode of a single transducer, the sound path length under solidified pure water is calibrated through a factory, the current water quality sound velocity is calculated in real time in a zero flow state, the zero offset of a 1MHz main channel is dynamically corrected, and a high-precision temperature sensor is omitted. Meanwhile, online water quality diagnosis is realized by utilizing a double-frequency cooperation mechanism: turbidity is quantized according to the amplitude ratio of 500kHz and 1MHz signals (based on the characteristics of high-frequency scattering sensitivity and high low-frequency penetrability), and bubbles are detected according to the time domain volatility of the 1MHz signals; and dynamically optimizing the flow metering precision of the main channel according to a diagnosis result by combining a sound velocity compensation model (the sound velocity is inversely proportional to the turbidity) and a graded bubble compensation model (the sound velocity or the flow is corrected according to the volatility). According to the method, medium interference is effectively overcome, measurement reliability is improved, and real-time monitoring and reporting of basic water quality (turbidity and bubbles) are achieved at low cost.
Owner:NINGBO WATER METER (GRP) CO LTD

Water conservancy water level monitoring device and method

InactiveCN120467466ADatabase updatingBiological modelsStream gaugeWater velocity
The invention belongs to the technical field of water conservancy monitoring, and discloses a water conservancy water level monitoring device and method, and the method comprises the steps: a monitoring point arrangement module of a monitoring mechanism reasonably arranges the number and positions of monitoring points; the flow velocity monitoring module monitors the water velocity; the meteorological data acquisition module acquires meteorological data; the echo sounder emits sound waves, and the water depth is calculated according to the sound wave propagation time and the sound velocity in water; the pressure water level gauge, the laser water level gauge and the radar water level gauge monitor the water level of water conservancy. The echo data analysis module analyzes the echo data; the comprehensive analysis module comprehensively analyzes the water level; the predictive analysis module predicts a water level trend and potential risks. The water level of water conservancy is monitored through various water level gauges, cross validation and high precision are achieved, and the sediment deposition thickness is accurately calculated by analyzing echo data; the comprehensive analysis module comprehensively evaluates the water level; the prediction analysis module integrates various monitoring equipment data and meteorological data, and predicts the water level trend and potential risks.
Owner:安阳市水资源事务中心

TF-SAW resonator and preparation method thereof, and filter

The invention provides a TF-SAW resonator, a preparation method thereof and a filter, and relates to the technical field of semiconductors. The interdigital electrode comprises piston structures, sub-bus bars and metal bumps, the piston structures are positioned at two ends of the acoustic part, it can be understood that the piston structures are arranged at the tail end areas of the acoustic part on the electrode finger strips, and larger sound velocity difference is realized by changing the sound velocity of the tail end areas; therefore, the transverse mode is reflected in different directions to avoid energy dissipation caused by resonance; on a propagation path of a transverse mode, the sub bus bars and the metal bumps are sequentially arranged, clutter interference is eliminated by causing sound velocity difference, so that clutter mode interference is inhibited to the greatest extent, the Q value is improved, the insertion loss flatness in a passband is improved, and the performance of the TF-SAW resonator is further improved.
Owner:深圳新声半导体有限公司

Ultrasonic phased array full-focusing imaging method for acoustic wave multi-path propagation compensation of layered composite material

The invention relates to an ultrasonic phased array full-focusing imaging method for acoustic wave multi-path propagation compensation of a layered composite material, which is characterized by comprising the following steps of: arranging an ultrasonic phased array probe with N array elements on a composite material piece to be detected, obtaining complete echo data by taking each array element as a transmitting array element and taking all array elements as receiving array elements in sequence in a full-matrix acquisition mode; a two-dimensional pixel grid is established in an imaging area, a Monte-Carlo perturbation mechanism used for representing the acoustic wave propagation uncertainty in the layered composite material is introduced into a propagation model for each emission array element-receiving array element-pixel point combination, and the acoustic beam emission direction, the propagation path and the equivalent acoustic velocity are subjected to random perturbation, so that the acoustic wave propagation uncertainty in the layered composite material can be represented. Generating a plurality of equivalent sound wave propagation paths, calculating two-way propagation time of each path, and performing weighted statistics on energy contributions of different paths according to array element sound beam directivity to obtain equivalent propagation time delays of pixel points; and performing delay correction on a full-matrix echo signal by using the equivalent propagation time delay, and performing coherent superposition on signals of all transmitting-receiving array element combinations to realize dynamic focusing of a full-pixel grid, and finally reconstructing an ultrasonic full-focusing imaging image with high resolution and high signal-to-noise ratio. The time delay error caused by propagation path deviation and sound velocity non-uniformity in the layered composite material can be effectively compensated, the focusing precision and spatial resolution of full-focusing imaging are improved, meanwhile, an existing TFM imaging frame does not need to be changed, and the method has good engineering implementability and popularization and application value.
Owner:CHINA JILIANG UNIV

Self-adaptive metering method of ultrasonic water meter

The invention discloses a self-adaptive metering method of an ultrasonic water meter, which relates to the field of water meter metering, and comprises the following steps: acquiring real-time water temperature data and real-time flow velocity data of a measured fluid, compensating the sound velocity of ultrasonic waves based on the real-time water temperature data to obtain a first compensated sound velocity, based on the first compensation sound velocity, an excitation voltage self-adaptive adjustment strategy with ultrasonic wave head-wave ratio regulation and control and a measurement frequency dynamic regulation and control strategy are executed, secondary compensation is conducted through a built error curved surface compensation model with the water temperature and the flow velocity as indexes, and the initial flow value is corrected through an error compensation value; by means of multi-parameter collaborative real-time optimization, high-precision measurement and low-power-consumption operation under all working conditions are achieved, the measurement precision in the full-scale and full-temperature range is remarkably improved, and by intelligently adjusting the measurement frequency, cooperating with the flow rate change rate and error model feedback and dynamically balancing the dynamic response speed and static power consumption, the measurement precision is improved. And finally, double optimization of precision and energy efficiency is achieved.
Owner:HANGZHOU WATERMETER CORP

Wind turbine generator blade damage judgment method and detection system based on voiceprint detection

The invention discloses a wind turbine generator blade damage judgment method and detection system based on voiceprint detection, and belongs to the technical field of wind turbine generator blade detection. The damage judgment method comprises the following steps: acquiring environmental parameters of a wind power plant, and establishing a sound velocity correction model based on the environmental parameters; acquiring a blade resonance sound signal, and correcting the blade resonance sound signal based on the sound velocity correction model to obtain a blade resonance sound signal with a high signal-to-noise ratio; performing FFT spectrum analysis on the blade resonance sound signal with the high signal-to-noise ratio, identifying the peak position of the first three-order natural resonance frequency of the blade, and performing analysis to obtain the current modal frequency, damping ratio and sub-band energy distribution entropy value of the blade; historical baselines of the modal frequency, the damping ratio and the sub-band energy distribution entropy of the blade in the healthy state are obtained, and the modal frequency offset, the damping ratio change rate and the acoustic impedance spectrum entropy of the blade are obtained; and wind turbine generator blade damage determination is carried out by using a high-precision time difference detection technology.
Owner:HUANENG CHONGQING FENGJIE WIND POWER CO LTD +1

Self-adaptive ultrasonic measurement method and system based on multichannel collaboration

The invention discloses a self-adaptive ultrasonic measurement method and system based on multi-channel cooperation, and relates to the technical field of ultrasonic measurement. The method comprises the following steps: collecting original flight time signals of each channel; meanwhile, environment data are collected in real time; original flight time signals are processed, effective signal arrival pre-flight time is extracted, and a fusion data set is constructed; constructing a two-dimensional sound channel spectrogram based on the multi-sound channel time sequence of the pre-flight time, and performing feature extraction based on a lightweight convolutional neural network to generate an abnormal confidence vector; analyzing the sound channel state based on the abnormal confidence vector; constructing a physical information neural network, and analyzing the corrected sound velocity value of each sound channel and the two-dimensional sound velocity field distribution on the section of the whole pipeline; training an online sequence extreme learning machine model in combination with historical measurement data; and based on the final fusion weight of each sound channel and the corresponding sound channel flow velocity, carrying out weighted fusion to generate a flow velocity optimal estimation value. And the measurement precision and robustness are improved.
Owner:SHANDONG HETONG INFORMATION TECH CO LTD

Underwater positioning system based on effective sound velocity compensation and multipath equalization

The invention provides an underwater positioning system based on effective sound velocity compensation and multipath equalization, which relates to the technical field of marine equipment and comprises an environment sensing and modeling module, a signal propagation characteristic analysis module, an intelligent signal processing and distance measuring module and a fusion positioning and quality evaluation module. The environment sensing and modeling module is used for constructing a dynamic three-dimensional sound velocity field and evaluating the reliability of the environment, the signal propagation characteristic analysis module is used for establishing a multi-path propagation model and extracting path characteristic parameters, and the intelligent signal processing and distance measuring module is used for suppressing multi-path interference and realizing high-precision distance measuring calculation. The fusion positioning and quality evaluation module is used for multi-source information fusion positioning and forming a quality feedback closed loop; the system can effectively cope with sound velocity temporal and spatial change and multipath interference in a complex marine environment, remarkably improves the precision, stability and robustness of underwater positioning of the underwater vehicle, and is suitable for the fields of deep sea detection, ocean engineering and the like.
Owner:CHINESE PEOPLES LIBERATION ARMY UNIT 92578

Ultrasonic array full-focusing detection scheme design method and device

The invention provides an ultrasonic array full-focusing detection scheme design method and device, and belongs to the field of zirconium alloy welding seam detection. The method comprises the steps that zirconium alloy welding seam microscopic data are obtained, and the correlation between the microscopic data and the anisotropy of the zirconium alloy welding seam is obtained; establishing an ultrasonic propagation simulation model in the zirconium alloy welding seam; establishing a zirconium alloy welding seam simulation test block; determining an ultrasonic detection range; calculating a first incident angle range and configuration parameters of the ultrasonic array; simulating the sound velocity change of the ultrasonic waves of which the incidence angles are distributed in the incidence angle range in the zirconium alloy welding seam simulation test block, and outputting an optimal sound velocity value; calculating the optimal incidence angle of the ultrasonic array in the incidence angle range; constructing an ultrasonic array based on the configuration parameters, and performing full-focusing imaging on the constructed ultrasonic array according to the optimal incident angle; and detecting defects in the zirconium alloy weld joint based on a full-focusing imaging result. The defect type identification precision and the defect position positioning precision can be improved.
Owner:ZHOUSHAN SPECIAL EQUIP TESTING RES INST

X-ray thermoacoustic imaging method based on diffusion model and sound velocity compensation

The invention discloses an X-ray thermoacoustic imaging method based on a diffusion model and sound velocity compensation, and relates to the technical field of X-ray thermoacoustic imaging and deep learning imaging reconstruction. According to the method, the influence of sound velocity non-uniformity on a thermal sound wave propagation path and time delay is fully considered, and a new method combining sound velocity compensation and diffusion model reconstruction is provided; on the premise that the hardware complexity of an imaging system is not increased, accurate correction of a wave propagation path is achieved through sound velocity modeling, and imaging artifacts and space positioning errors are effectively avoided; meanwhile, the image inversion framework based on the conditional diffusion model has excellent noise suppression and high-frequency detail recovery capabilities, and can generate a high-quality thermoacoustic image with a clear structure and remarkable contrast under the imaging conditions of low signal-to-noise ratio, low energy dose and the like.
Owner:CHONGQING UNIV OF TECH

Multimedium three-dimensional flaw detection system based on ultrasonic pulse echoes

The invention discloses a multi-medium three-dimensional flaw detection system based on ultrasonic pulse echoes. The multi-medium three-dimensional flaw detection system comprises a synchronous data acquisition module, a temperature compensation module, a multi-physical field simulation optimization module, a signal processing module and a three-dimensional imaging and output module, the synchronous data acquisition module scans an object, records coordinates and synchronously transmits and receives ultrasonic echoes; the temperature compensation module calculates real-time sound velocity according to the water temperature, the real-time sound velocity is used by the multi-physics field simulation module, and the multi-physics field simulation module simulates sound wave propagation and generates a defect-free theoretical waveform as a reference by combining intrinsic parameters of an object and sound wave propagation parameters; the signal processing module carries out processing and feature extraction on actually measured echoes, and compares the actually measured echoes with a reference to identify defect signals; and the three-dimensional imaging module associates the signals with the coordinates, a three-dimensional model is generated by adopting slice reconstruction and a compressed sensing algorithm, and defects are visualized, so that the precision, the efficiency and the environmental adaptability of three-dimensional flaw detection can be improved.
Owner:DALIAN MARITIME UNIVERSITY

Multi-channel underwater acoustic signal transmitting and measuring system and signal processing method

The invention relates to the technical field of underwater acoustic engineering and ocean exploration, in particular to a multi-channel underwater acoustic signal transmitting and measuring system and a signal processing method, which are used for solving the problems that the existing multi-channel underwater acoustic signal processing generally depends on fixed threshold detection or simple time sequence alignment, and the signal processing efficiency is low. The problem that residual vibration, local noise abrupt change or multipath reverberation is easily misjudged as an effective first arrival signal in a complex underwater environment due to the fact that the influence of the physical response characteristic of a transducer on emission time calibration is not considered and effective verification on whether a candidate arrival structure accords with a sound wave propagation physical rule is lacked is solved. According to the invention, a multi-channel energy time sequence and hydrophone space geometrical relationship is fused through an underwater sound propagation initial physical judgment module, a judgment mechanism is constructed based on distance-time consistency of sound propagation, and self-consistent verification is realized by combining a cross-channel arrival sequence and sound velocity constraint. And the accuracy, the robustness and the physical interpretability of the judgment of the effective launching time of the underwater sound are obviously improved.
Owner:HANGZHOU RENMU TECH CO LTD

Power transmission line external damage risk identification method fusing image and sound features

The invention provides a power transmission line external damage risk identification method fusing image and sound features, and belongs to the technical field of power supply. Image frames collected by a camera are processed based on a target detection algorithm, when external damage machinery is identified, a target bounding box is output, and the timestamp of the current image frame is recorded; the microphone array is triggered to carry out audio acquisition, and an acoustic reference signal pointing to the external breaking mechanical direction is generated; visual features and Mel frequency cepstrum coefficient MFCC features are extracted, and acousto-optic time delay is calculated; and determining the vertical distance from the external breaking machine to the power transmission line based on the sound velocity, the acousto-optic time delay and the installation parameters of the camera, and carrying out early warning according to the vertical distance and the voltage grade of the power transmission line. Therefore, through a collaborative fusion mechanism of visual sense and acoustic perception, the problems of high false alarm rate, poor positioning precision and large response delay in external damage monitoring of the power transmission line in the prior art are effectively solved, and the monitoring accuracy and practicability are improved.
Owner:HENAN TIEYUE DIGITAL TECHNOLOGY CO LTD

TF-SAW resonator and preparation method thereof, and filter

The invention provides a TF-SAW resonator, a preparation method thereof and a filter, and relates to the technical field of semiconductors. The interdigital electrode comprises piston structures, sub-bus bars, metal bumps and recesses, the piston structures are positioned at two ends of the acoustic part, it can be understood that the piston structures are arranged at the tail end areas of the acoustic part on the electrode finger bars, and larger sound velocity difference is realized by changing the sound velocity of the tail end areas; therefore, the transverse mode is reflected in different directions to avoid energy dissipation caused by resonance; according to the TF-SAW resonator, the sub bus bars, the metal bumps and the recesses are arranged on a propagation path of a transverse mode, clutter interference is eliminated by causing sound velocity difference, so that clutter mode interference is inhibited to the greatest extent, the Q value is improved, the insertion loss flatness in a passband is improved, the performance of standing waves in the passband is improved, the insertion loss is improved and the like, and the performance of the TF-SAW resonator is further improved.
Owner:深圳新声半导体有限公司

Full-focus imaging optimization method applied to multi-layer composite material

The invention relates to the technical field of nondestructive testing, in particular to a full-focus imaging optimization method applied to a multi-layer composite material. According to the method, full-focus imaging of the multi-layer composite material is optimized through a systematic process, FMC data of a defect-free area are collected, elastic constant combinations of all layers are enumerated, a sound velocity curve is calculated, a full-focus image is generated based on equivalent sound velocity, and finally the optimal elastic constant is screened according to the average amplitude of the bottom surface. The large-angle sound velocity information is covered through the elastic constant combination, the problem that angle coverage is limited is solved, and higher imaging precision is achieved for a large-thickness composite material; parameters are automatically screened by using image amplitudes, so that low efficiency and errors caused by manual judgment of attenuation signal peak values are avoided, and meanwhile, the upper bound of the range of detectable propagation angles is improved; and the sound velocity is calculated by combining heterogeneous layering characteristics, so that the defect identification precision is greatly improved compared with that of a traditional homogeneous model.
Owner:HEFEI GENERAL MACHINERY RES INST +3

Passive underwater cooperative positioning system and method

According to the passive underwater cooperative positioning system and method provided by the invention, an intelligent signal processing and analysis module in the system receives a target underwater sound backscattering signal and a target environment parameter output by an environment adaptive feedback module, and then a path identification result and a positioning result are obtained by combining an identification model; obtaining a sound velocity correction value and a propagation time correction value based on the target environment parameters and a sound velocity correction model so as to obtain the moving speed of the target object; the cooperative positioning calculation module predicts the positioning information of the next moment based on the historical positioning information and the positioning information of the current moment; the environment self-adaptive feedback module receives the underwater sound backscattering signals generated by the multi-mode signal acquisition module and the acquired environment parameters, and transmits the underwater sound backscattering signals and the acquired environment parameters to the intelligent signal processing and analysis module as target underwater sound backscattering signals and target environment parameters; and the dynamic adjustment module is also used for dynamically adjusting the state parameters of the underwater acoustic backscattering signals and the environmental parameters so as to obtain new target underwater acoustic backscattering signals and target environmental parameters.
Owner:BEIHANG UNIV

Irregular water area underwater topographic mapping method based on multi-beam fusion

The invention relates to the technical field of beam fusion, and discloses an irregular water area underwater topographic surveying and mapping method based on multi-beam fusion, which comprises the following steps: acquiring multi-voyage sounding data of a target irregular water area by using a multi-platform multi-beam sounding system such as a coastal patrol ship and an unmanned surveying ship, and performing sound velocity profile correction, attitude correction and tide level reduction to obtain a target irregular water area; unifying to the same space-time reference and plane rectangular coordinate system, and constructing an initial underwater terrain digital elevation model in an irregular water area range by adopting Gaussian weighted interpolation; defining an influence area by taking a hydraulic structure as a center, decomposing a local terrain into a background terrain and a scouring residual error, performing polar coordinate conversion and angular terrain spectrum analysis in the influence area, and calculating an axisymmetric form dominance index of the scouring pit; and constructing a topographic form shaping factor based on the axisymmetric form dominance index of the scouring pit, the maximum scouring depth and the influence radius, performing frequency domain modulation on the Fourier coefficient, and reconstructing the corrected local topography to obtain a final underwater topography DEM.
Owner:NANJING HANDONG BOHUI SURVEYING & MAPPING CO LTD

Underwater facility defect geometric feature measurement method, system, medium and equipment

The invention relates to the technical field of underwater facility measurement, and provides an underwater facility defect geometric feature measurement method and system, a medium and equipment, and the method comprises the steps: calculating the actual sound velocity based on the water temperature, water pressure and salinity, correcting a sonar point cloud, calculating the sound velocity change rate, and adjusting the size of a filtering window, performing smooth filtering on the corrected sonar point cloud; for the surface image, calculating an image dark channel, after smoothing the dark channel image through scattering filtering, calculating transmissivity, fusing a scattering coefficient, removing surface image scattered light, and correcting the scattering coefficient through turbidity; based on the salinity and the water temperature, the underwater refraction angle of the laser is calculated, and the three-dimensional scanning point cloud is corrected; registering and fusing the point clouds to generate a facility surface point cloud model; based on the surface image, texture information of the facility surface is extracted, after the texture information is mapped to the facility surface point cloud model, a defect area is segmented, and geometric feature parameter extraction is carried out. And the detection reliability in a complex water area environment is improved.
Owner:STATE GRID INTELLIGENCE TECHNOLOGY CO LTD +1

Seawater temperature, salinity and sound velocity inversion method based on Brillouin laser radar

The invention discloses a seawater temperature, salinity and sound velocity inversion method based on a Brillouin laser radar, and belongs to the technical field of marine environment monitoring. According to the method, the temperature, salinity and sound velocity of seawater are inverted by measuring the Brillouin frequency shift and the Brillouin line width and combining the MLP neural network; the method specifically comprises the steps of collecting seawater parameter data of different sea areas, different seasons and different depths and corresponding frequency shifts and line widths; carrying out data preprocessing and standardization on the collected data; and establishing an inversion model by using an MLP neural network, and outputting temperature, salinity and sound velocity. The multi-layer perceptron MLP neural network processes frequency shift and line width data measured by the Brillouin laser radar, high-precision and real-time inversion of seawater temperature, salinity and sound velocity is achieved, the parameter range is remarkably expanded, the inversion precision is improved, and efficient and reliable marine environment monitoring is provided.
Owner:NANJING MULTI BASE OBSERVATION TECH RES INST CO LTD

Multi-sound-velocity photoacoustic image reconstruction method and device based on implicit neural representation

The invention provides a multi-sound-velocity photoacoustic image reconstruction method and device based on implicit neural representation, and relates to the technical field of image processing. The method comprises the following steps: adjusting parameters of an implicit neural representation network: obtaining first initial sound pressure distribution and first sound velocity distribution through the implicit neural representation network based on space coordinates in an imaging area, obtaining a predicted detector signal based on the first initial sound pressure distribution and the first sound velocity distribution through a differentiable acoustic forward propagation model, and minimizing the difference between the predicted detector signal and the detector measurement signal to update parameters of the implicit neural representation network; iteration is carried out in this way until a preset convergence condition is met; and using the implicit neural representation network after parameter adjustment to obtain second initial sound pressure distribution based on the space coordinates in the imaging area. According to the invention, photoacoustic image reconstruction can be realized without a sound velocity distribution diagram or a pairing truth value.
Owner:THE FIRST MEDICAL CENT CHINESE PLA GENERAL HOSPITAL

Parameter measurement method and device based on dual-band mode, equipment and storage medium

The invention relates to the technical field of meteorological observation, in particular to a parameter measurement method and device based on a dual-band mode, equipment and a storage medium. Generating a dual-band excitation signal according to the aligned sine wave signal; analyzing the echo signal according to a preset gain coefficient, a time difference method and a preset attitude compensation formula to obtain a reconstructed quasi-unipolar pulse, an actual wind speed, a horizontal wind direction angle, a pitch angle, a three-dimensional wind speed vector, a roll angle and a real wind direction; acquiring real-time air pressure, and correcting a preset standard state sound velocity according to a preset sound velocity correction formula and the real-time air pressure to obtain a corrected sound velocity; according to the scheme, a dual-band signal attached to a medium is generated, after efficient transmission analysis, high-resolution pulses and multi-dimensional wind field parameters are obtained by means of gain, a time difference method, attitude compensation and the like, the sound velocity is corrected in combination with air pressure, comprehensive, accurate and rapid updating of data are considered, and the measurement reliability is improved.
Owner:DATANG TUOKEXUN WIND POWER DEV