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127 results about "Cross correlation analysis" patented technology

Cross-Correlation is a tool that is well suited for that specific purpose. Cross-Correlation analyzes the relationship between two data series, calculating a value ranging between one (1.0) and negative one (-1.0).

Techniques using heat flow management, stimulation, and signal analysis to treat medical disorders

A device and a method of use for treating a medical disorder by surgically implanting into a patient at least one sensor element capable of detecting and conveying cell signals: attaching a management unit such that a micro controller of the management unit is connected to at least one sensor element; and connecting the management unit via a lead bundle to at least one treatment device. The treatment device may be an electrical stimulation device, a magnetic stimulation device, a heat transfer device, or a medication delivery device. Responsive to signals from the one or more sensor elements, mathematical algorithms of the management unit use wavelet crosscorrelation analysis to prompt delivery of at least one treatment modality, such heat transfer, current pulses, magnetic stimulation or medication. The medical disorder may arise from the brain, central nervous system or organs and tissues outside of the central nervous system.
Owner:THE JOHN HOPKINS UNIV SCHOOL OF MEDICINE

Partical image velocimetry suitable for x-ray projection imaging

A 2D or 3D velocity field is reconstructed from a cross-correlation analysis of image pairs of a sample, without first reconstructing images of the sample spatial structure. The method can be implemented via computer tomographic x-ray particle image velocimetry, using multiple projection angles, with phase contrast images forming dynamic speckle patterns. Estimated cross-correlations may be generated via convolution of a measured autocorrelation function with a velocity probability density function, and the velocity coefficients iteratively optimised to minimise the error between the estimated cross-correlations and the measured cross-correlations. The method may be applied to measure blood flow, and the motion of tissue and organs such as heart and lungs.
Owner:4DX LTD

Fluid conveying pipe leakage acoustic emission time-frequency positioning method

ActiveCN104747912AImprove completenessSolve the problem of large leak location errorsPipeline systemsFrequency spectrumTime delays
The invention relates to a fluid conveying pipe leakage acoustic emission time-frequency positioning method. The fluid conveying pipe leakage acoustic emission time-frequency positioning method comprises the following steps of picking up acoustic emission signals through an acoustic sensor and a vibration sensor which are arranged at two ends of a pipe leakage point respectively and performing cross-correlation analysis on the acoustic emission signals which are picked up; performing time-frequency analysis on cross-correlation functions of the two channels of acoustic emission signals through smooth pseudo Wigner-Ville time-frequency distribution; extracting the time and frequency information corresponding to time-frequency spectrum peak values of the cross-correlation functions of the acoustic emission signals during pipe leakage; serving the time information corresponding to the peak values as the time delay of two observation signals and determining the transmission speed of the leakage acoustic emission signals along a pipe through table look-up on a frequency dispersion curve according to the frequency information of the peak values; determining the pipe leakage position through the time delay and the timely determined acoustic speed. The fluid conveying pipe leakage acoustic emission time-frequency positioning method can be used for performing accurate positioning on the leakage point under the conditions that the leakage acoustic emission frequency dispersion of the fluid conveying pipe is serious and the acoustic speed is difficult to be determined and meanwhile the correlation functions of the single frequency leakage signals are extracted for the time delay estimation and accordingly the degree of correlation of the leakage signals is enhanced and the leakage positioning error is further reduced.
Owner:重庆富世恒睿物联网科技有限公司

Mutual correlation technology for measuring permeability stress sensitivity of ultra-low permeability rocks

ActiveCN103528934ASolve the problem of permeability stress sensitivity measurementLarge stress potentialPermeability/surface area analysisCross correlation analysisRock core
The invention provides a mutual correlation technology for measuring permeability stress sensitivity of ultra-low permeability rocks. The technology comprises the following steps: a) an ultra-low permeability rock core of shale or tight sand rock and the like is selected, and processed into a cylindrical sample; b) a cylindrical steel block standard sample is processed for system calibration; c) the measurement of ultra-low permeability is carried out through a periodic oscillation method, the pore medium can employ gas or water, and the measurement result of the steel block is used for calibrating the system; d) the rock core is placed in a clamp holder, and applied with confining pressure and pore pressure, the rock core is saturated, An upstream sine pressure wave is applied and kept constant, the responses of the downstream pressure waves at different confining pressures are measured; e) the downstream pressure waves at different confining pressures are subjected to mutual correlation analysis, the change of permeability with confining pressure is obtained. Combined with a periodic oscillation method for measurement of permeability of ultra-low permeability rocks, pressure waveforms for measurement of permeability are subjected to mutual correlation analysis, the precision of measurement of permeability change is raised, and the problem of measurement of ultra-low permeability stress sensitivity is solved.
Owner:CHINA UNIV OF PETROLEUM (BEIJING)

Method for applying seismic multiattribute parameters to predicting coal seam thickness

The embodiment of the invention provides a method for applying seismic multiattribute parameters to predicting the coal seam thickness. The method comprises: a suitable time window is selected in a three-dimensional offset data body, seismic attribute data of amplitude, frequency, and instantaneity and the like are extracted from the time window, and a seismic attribute database is established; a correlated analysis is executed on seismic attributes and coal seam thicknesses and cross-correlation analyses are further executed on the seismic attributes, so that a plurality of seismic attributes that are most meaningful are optimized as basic parameters of a coal seam thickness prediction model; with combination of known boring data, a multicomponent polynomial regression model and a BP artificial neural network model of between all the seismic attributes and the coal seam thicknesses are established by utilizing a multicomponent polynomial regression method and a BP artificial neural network method; and the models are utilized to predict coal seam thicknesses. According to the method provided in the embodiment of the invention, because multiattribute parameters are considered, obtained calculating models are perfect and realistic; an effect for prediction of the coal seam thickness is good; and credibility and accuracy are high.
Owner:BC P INC CHINA NAT PETROLEUM CORP +1

Apparatus for measuring combustion chamber flue gas temperature by utilizing acoustics

InactiveCN101403643ATimely judge the combustion situationWith portable measurementThermometers using physical/chemical changesTransceiverCombustion chamber
The invention belongs to the high-temperature off-gas temperature measurement technical field, in particular to an apparatus adopting the acoustics to measure the temperature of off-gas in a hearth. A set of sound-wave transceiver comprising a sound-wave duct, an electric speaker and a reinforced microphone is respectively arranged onto the symmetrical positions of the wall on two sides of the boiler hearth; the electric speakers send out sound signals which are simultaneously received by the reinforced microphone of the same side or the opposite side and are converted into voltage signals; after the voltage signals pass through a signal regulator, the signals are input through a cable into a double-channel data collecting card to be converted into digital signals; then a cross correlation is adopted for analysis to obtain the time-of-flight of sound wave and finally the computer and software are adopted to figure out the temperature of off-gas. The work of the apparatus is not limited by the high-temperature, dusts, corrosion and onflow and the like. complicated and rigid conditions in the boiler and the apparatus is provided with the features of non-insertion style, accuracy, real-time and portable measurement; and the apparatus can replace the traditional hearth high-temperature probes and can in time judge the combustion condition of the boiler for regulation and control.
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING)

Coordinated control oriented trunk line crossing correlation analysis and division method

InactiveCN105825690AComprehensive correlation analysis methodAccurately quantify the degree of associationRoad vehicles traffic controlControl orientedTraffic capacity
The invention discloses a coordinated control oriented trunk line crossing correlation analysis and division method. The method comprises the steps that 1, traffic parameters used for correlation analysis of crossings of a trunk line are acquired; 2, signal timing plan data generated when single-point control is executed on all the crossings of the trunk line is acquired; 3, the correlation degree of the adjacent crossings is determined; 4, the coordinated control crossings of the trunk line are divided. According to the method, a comprehensive correlation degree index is set up to express the relevancy between the adjacent signal crossings of the trunk line, five key factors influencing the relevancy of the adjacent crossings are comprehensively considered, maximization of the phase coordinating and traffic flow traffic capacity coordinating capacity is adopted as a main target, the correlation degree of the adjacent crossings is accurately quantized, and the scientific and comprehensive correlation analysis method is set up.
Owner:BEIHANG UNIV

Particle image velocimetry suitable for x-ray projection imaging

A 2D or 3D velocity field is reconstructed from a cross-correlation analysis of image pairs of a sample, without first reconstructing images of the sample spatial structure. The method can be implemented via computer tomographic X-ray particle image velocimetry, using multiple projection angles, with phase contrast images forming dynamic speckle patterns. Estimated cross-correlations may be generated via convolution of a measured autocorrelation function with a velocity probability density function, and the velocity coefficients iteratively optimised to minimise the error between the estimated cross-correlations and the measured cross-correlations. The method may be applied to measure blood flow, and the motion of tissue and organs such as heart and lungs.
Owner:4DX LTD

Ultrasonic non-destructive abrasion-resistant coating thickness and elastic modulus measuring method

The invention provides an ultrasonic non-destructive abrasion-resistant coating thickness and elastic modulus measuring method, which belongs to the technical field of ultrasonic non-destructive detection. The method is based on a pulse echo technology and uses a single immersion focusing probe to acquire an echo signal of an abrasion-resistant coating / metal matrix specimen once to effectively extract longitudinal wave and transverse wave signals of back and forth interfaces of the coating. Spectral analysis is carried out on longitudinal wave and transverse wave signals to acquire corresponding ultrasonic reflection coefficient amplitude spectrum (URCAS). A cross-correlation analysis two-parameter inversion technology is combined to measure the longitudinal wave sound velocity V2l and the thickness d of the coating at the same time. Through the inversion of the thickness d and the resonant frequency fnt of shear wave URCAS, the transverse wave sound velocity V2t of the coating is calculated. Density rho2 is corrected through the combination with the coating porosity counted by a metallographic method. According to an elastic modulus expression, the elastic modulus is measured. According to the method, complicated operation of conventional ultrasonic multi-probe combination or multi-angle incidence is overcome; the shortcoming that the poisson ratio is assumed to be fixed by a surface wave method is overcome; and the problem of ultrasonic quantitative measurement of the elastic modulus of the coating is solved.
Owner:DALIAN UNIV OF TECH

Vehicle load dynamic weighing method for orthotropic bridge deck steel box girder bridge

The invention discloses a vehicle load dynamic weighing method for an orthotropic bridge deck steel box girder bridge, which relates to the field of bridge health monitoring. The method comprises the following steps of: mounting a fiber grating strain sensor at the bottom of a U-shaped rib of an internal top plate of an orthotropic bridge deck steel box girder; measuring longitudinal bridge strain of the U-shaped rib when a vehicle passes through the position of the sensor; converting the strain into an optical signal by the sensor; demodulating the optical signal by using a fiber grating demodulator; carrying out cross-correlation analysis on actually measured strains of measuring points on the same U-shaped rib in the steel box girder at different sections so as to determine vehicle speed of the vehicle; analyzing actually measured strain area vectors of measuring points on different U-shaped ribs in the steel box girder at the same section; and carrying out angle Cosine distance analysis by using a strain effect linear area vector of the U-shaped rib of the steel box girder so as to figure out transverse acting position and weight of each vehicle on a running lane. The vehicle load dynamic weighing method for the orthotropic bridge deck steel box girder bridge, disclosed by the invention, has the advantages of convenience for mounting, low manufacturing price, no need of interrupting transportation, no excavation or damage of the road surface and capability of achieving nondestructive and automatic dynamic weighing of the bridge vehicle load.
Owner:CHINA RAILWAY BRIDGE SCI RES INST LTD +1

Support card identification method and device

The invention provides a support card identification method and device. The method comprises steps that based on historical conversation record of each user, conversation characteristics of each user are analyzed, and a user group corresponding to different conversation characteristics is established; communication data of each user is acquired from service provider data, and the communication data comprises user data, the package information, the bill information and a detailed conversation list; according to the communication data of each user, in combination with association factors, cross correlation analysis on the user group corresponding to the different conversation characteristics is carried out, support card users of who the conversation characteristics are the support card characteristics are identified, and the association factors comprise the conversation time, a conversation opposite-end number and a conversation place. The method is advantaged in that based on big data analysis, a series of analysis on the communication data of the user is carried out, abnormal behaviors of the users are explored, according to the conversation characteristics of the support card users, the support card users can be accurately and reliably identified, and support card behaviors can be effectively inhibited.
Owner:北京道隆华尔软件股份有限公司

Method for testing water surface fine-speed flow field

The invention relates to a method for testing a water surface fine-speed flow field. A light source is used for illuminating tracer particles, and with the cooperation of a CCD aperture, a V-shaped convergence and divergence flow field formed by tracer particles transmitted to the water surface by internal waves excited by a dragging model is photographed. The measurement of flow field speed is realized by following the speed of the tracer particles which move together with the flow field by using the above principle. The method is simple and effective, is high in application flexibility, and realizes non-contact and non-interference 'surface type' measurement of an mm / s order water surface flow field.
Owner:中国船舶重工集团公司第七〇二研究所

Real-time absolute ranging method and system based on single-chamber dual-femtosecond optical comb cross-correlation analysis

The invention discloses a real-time absolute ranging method and system based on single-chamber dual-femtosecond optical comb cross-correlation analysis. The method comprises steps: S1, two simultaneously-outputted femtosecond optical combs with different repetition frequencies are generated, the two different repetition frequencies are fr1 and fr2, and the repetition frequencies are locked to an atomic clock by frequency stabilization control; S2, after the beam of the two femtosecond optical combs passes through an interferometer optical path module, the orthogonal polarization components ofoptical comb pulse return light (reference light and measurement light) and local optical comb pulses are measured, and after combination, two groups of femtosecond laser pulse pairs with mutually-perpendicular polarization directions are generated; S3, two-path optical balance cross-correlation signals for reference and measurement are generated, and the signales can be generated by a femtosecondpulse cross-correlation analysis unit in the embodiment of the invention; and S4, the balance cross-correlation signals are subjected to high-speed digital signal analysis processing to obtain a ranging result. The system is the device used for executing the above method. The method and the system disclosed in the invention have the advantages of large ranging range, fast updating speed, high measuring precision and simple operation and the like.
Owner:中国人民解放军火箭军工程大学

Optical flow sensor

An optical flow sensor determines the velocity of a moving flow of air or other gas utilizing a plurality of photodetectors spaced apart in a direction parallel to the direction of gas flow. An optical beam is transmitted across the flowing gas and falls upon the photodetectors. Scintillations that occur in the flowing gas due to eddies and particulates in the gas are detected in all of the photodetectors, but at slightly different times due to the longitudinal separation of the photodetectors in the direction of gas flow. The output signals of the photodetectors are conditioned and amplified and transformed to digital form. Temporal cross correlation analysis is then performed on the digitized signals in a digital signal processor. A time differential between signals from the different photodetectors is then calculated electronically. The velocity of gas flow is then determined by dividing the spatial distance of separation between adjacent photodetectors by the time difference at which the same scintillation event is detected by each photodetectors.
Owner:OPTICAL SCI

Multi-field measurement platform for single bubble collapse and material boundary coupling characteristics

InactiveCN108896106AAccurately record the evolution process of macroscopic cavitationAccurate recording of transient cavitation pulsation propertiesMeasurement apparatus componentsResponse processMulti field
The invention discloses a multi-field measurement platform for single bubble collapse and material boundary coupling characteristics. The multi-field measurement platform comprises a test board, a test water tank, an electric spark generator, a transient bubble morphological observation system, a transient bubble motion field measurement system, and a structural stress acquisition system. The electric spark generator generates single bubbles and mutual coupling between the bubbles and test board is carried out; the transient bubble morphological observation system carries out qualitative and quantitative analyses on the geometrical scale of the bubble morphology by using high-speed video observation and image processing technologies; the transient bubble motion field measurement system uses a tracer particle in a light source illumination flow field and records an image, carries out a cross-correlation analysis on adjacent images in an image sequence to obtain a transient velocity vector field, and carries out processing to obtain velocity field and vorticity field information; and the structural stress acquisition system analyzes a correlation relationship and an action mechanismof a nearby bubble collapse load of the test board and test board wall surface deformation at different initial distances according to the dynamic response process of the wall surface of the test board.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY

Detecting identifying and positioning method for fire-fighting water pipe network leakage

The invention discloses a detecting identifying and positioning method for fire-fighting water pipe network leakage, and belongs to the field of fire safety. The method includes the steps of (1) multiple sets of vibrating sensors collect fire-fighting water pipe network acoustic emission signals synchronously; (2) a correlation matrix is established through synchronizing signals, whether leakage occurs or not is judged, and leaking pipelines are identified if the leakage occurs; (3) data detected by the sensors in the direction of the leaking pipelines are extracted; (4) EEMD and energy feature extraction decomposition are carried out to obtain an IMF containing leakage source information; (5) cross-correlation analysis is carried out on multiple sets of IMF data to obtain a time difference, and positions of leakage points are calculated; (6) the positions of multiple sets of leakage points are weighted to obtain finial positions of the leakage points. According to the method, the problem that extinguishment water pressure or flow is insufficient due to fire-fighting water pipe network leakage is solved, and a fire-fighting water pipe network can be really used when needed.
Owner:天津安博瑞尼科技股份有限公司

Method and device for measuring flow speed of dense paste based on electromagnetic signal cross correlation

The invention relates to a method and device for measuring the flow speed of a dense paste based on electromagnetic signal cross correlation. The device comprises a test tube section, a primary instrument and a secondary instrument. When the dense paste flows through a field coil 1 or 2 during pipeline conveyance, a current carrier of the dense paste performs movements of cutting magnetic induction lines in an applied magnetic field, and an electromotive force vertical to the flowing direction of the dense paste is formed; electromotive force signals in the two field coils are guided out by an electrode to be acquired, processed and analyzed; and the delay time of the two field coils is calculated by a cross correlation analysis method of two measuring points, and the quotient of the separation distance and the delay time of the two field coils is the flow speed of the dense paste. The method and the device solve the difficult problem that a special measuring device and a special measuring method for measuring the flow speed of the dense paste on a project site are not provided, and a condition for monitoring the condition of the project site and accurately controlling the flow of the dense paste is provided.
Owner:CHINA UNIV OF MINING & TECH (BEIJING)

Method and device for predicting rock drillability of wildcat well before drilling

The invention provides a method and a device for predicting rock drillability of a wildcat well before drilling. The method includes: picking up layer velocities of different layers of wildcat well rocks by the aid of a seismic velocity spectrum for the wildcat well rocks to be drilled; performing correlation analysis by the aid of the layer velocities of the different layers of the wildcat well and other drilled rocks, and selecting a certain drilled well with a rock structure similar to the wildcat well; training a feedforward BP (back-propagation) neural network according to seismic data and core test data of rocks of the selected drilled well to establish a model for predicting the rock drillability of the wildcat well before drilling; and predicting the rock drillability of the wildcat well by the aid of the trained feedforward BP neural network and the layer velocities of the different layers of the wildcat well rocks. By the aid of the method and the device, the relationship between each layer velocity and the rock drillability can be found, important data can be provided for reasonably selecting drilling modes, drill bit types and designed drilling parameters, drilling speed can be increased, and drilling cost can be reduced.
Owner:CHINA UNIV OF PETROLEUM (BEIJING)

Dangerous rock mass fracture early warning method and system

ActiveCN111275931ARealize detection and early warningFacilitate regional monitoring and early warningAngle measurementTransmission systemsCross correlation analysisMining engineering
The invention provides a dangerous rock mass fracture early warning method and system, and the method comprises the steps of installing a plurality of sensors on a dangerous rock mass to collect a rock vibration signal and the attitude information, and transmitting the rock vibration signal and the attitude information to a data processing center through wireless networking; and using the data processing center to perform cross-correlation analysis on the rock vibration signals and the attitude information acquired by the different sensors so as to judge the state of the dangerous rock body. According to the scheme, the problems that an existing early warning method is difficult in early warning in advance and high in cost, are solved, the dangerous rock bodies in multiple areas can be monitored and early warned at the same time, the accurate early warning can be achieved in advance, the hardware cost can be reduced, and the method and the system are simple and easy to implement.
Owner:HUBEI UNIV FOR NATITIES +1

Method and system for transformer area and electric energy meter state evaluation based on anomaly analysis

The invention relates to a method for transformer area and electric energy meter state evaluation based on anomaly analysis. The method is characterized in that the method comprises the following steps: (1) carrying out comprehensive analysis on an abnormal event and original data so as to obtain the abnormal condition of a transformer area; (2) performing cross correlation analysis on the acquired abnormal condition of the transformer area, outputting an abnormal reason and an abnormal level of an electric energy meter, and diagnosing the reason and the abnormal level causing the abnormalityof the electric energy meter; and (3) evaluating the states of the transformer area and the electric energy meter based on the reason of the abnormality of the electric energy meter and the abnormality level diagnosis result. The invention further relates to a system for transformer area and electric energy meter state evaluation based on anomaly analysis. The system comprises an anomaly transformer area analysis module, an anomaly association analysis module and a transformer area and electric energy meter state analysis module. Accurate evaluation of the transformer area and the electric energy meter state is realized, the work efficiency is improved, invalid work orders and on-site troubleshooting times are effectively reduced, and a lot of manpower and material resource costs are saved.
Owner:ELECTRIC POWER SCI & RES INST OF STATE GRID TIANJIN ELECTRIC POWER CO +2

Self-adaptive valid signal type positioning method for determining leakage of fluid pipeline

The invention belongs to the technical field of leakage and loss prevention, examination and position determining, and discloses a self-adaptive valid signal type positioning method for determining leakage of a fluid pipeline. The method comprises the steps of selecting a primary function of wavelet decomposition based on a pipeline leakage signal; determining the number of the optimal decomposition layer of the wavelet decomposition; determining the threshold, and performing wavelet denoising on the leakage signal by a soft-threshold method; setting estimation length and shift step length ofa valid signal; determining the valid signal in the leakage signal; determining the time delay value of the leakage signal arriving at the head end and the tail end of the pipeline based on the validsignal in the leakage signal; decreasing the length of the valid signal to obtain two time delay value sets; counting the average value of the three time delay value sets to obtain the final time delay value; determining the difference of the times of the leakage signal arriving at the head end and the tail end of the pipeline; and calculating the position of a leakage source based on the time difference. Compared with an existing positioning method, the method has the advantages that the influence of noise on the leakage signal is reduced; and the leakage positioning error is reduced.
Owner:XIDIAN UNIV

Polyethylene valve sealing performance room temperature low pressure test method

The invention provides a polyethylene valve sealing performance room temperature low pressure test method. A test stand self-contained closed-loop control system is utilized to perform automatic pressurization on a valve test cavity and a standard cylinder to achieve test standard pressure with indoor air acting as a test medium under the premise of confirming reliable sealing of the valve end surface and no leakage of the air passage of the test stand. Temperature and change of differential pressure of test air in the valve test cavity and the standard cylinder are detected synchronously by utilizing a temperature sensor and a differential pressure sensor, and all two-dimensional data in the time period of pressurization testing or the time period before leakage alarm are acquired and transmitted to a single-chip microcomputer to perform cross correlation analysis. Valve sealing performance judgment is given on the basis of a certain differential pressure drop gradient value within unit period of time according to the no leakage necessary and sufficient conditions that any points on a fitting curve of medium temperature difference and differential pressure at the same time axis have the same change of gradient, and temperature and pressure values of any time have a single proportional relationship. The method has no requirement for a constant temperature environment, and has the characteristics of being high in resolution and rapid and high-efficiency.
Owner:CHINA JILIANG UNIV

Urban underground gas pipeline monitoring system

The invention provides an urban underground gas pipeline monitoring system. The urban underground gas pipeline monitoring system comprises a monitoring terminal, a wireless transmission module and real-time communication monitoring equipment. Gas concentration and negative pressure wave signal data are collected through sensors; data fusion is conducted through a STM32C8T6 processor; leakage sources are located by adopting an improvement cross-correlation analysis method; processed data are transmitted to a ground concentrator module through a LoRa wireless module; and data detected by different detection nodes are fused by a concentrator, and then the data are transmitted to a OneNET cloud platform and terminal equipment for display through a narrow band Internet of things (NB-IoT) wireless communication module. When gas leakage occurs, the working staff in a monitoring center are notified in time to deal with the situation through alarm display and sending of alarm text messages. According to design principles, outstanding anti-interference and signal penetrating capacities of the LoRa wireless module are utilized under the ground to conduct communication so that stability of signals can be guaranteed; on the ground, through the NB-IoT module, uploading of data and intercommunication between users are achieved; and by means of the platform of Internet of things, updating, adjustment and pre-overhaul of products are convenient.
Owner:ANHUI UNIV OF SCI & TECH

Rotating blade underwater dynamic deformation binocular measurement system of composite material propeller model

ActiveCN109682575AGrasp the dynamic deformation in timeDoes not affect hydrodynamic performanceHydrodynamic testingCross correlation analysisSoftware system
The invention discloses a rotating blade underwater dynamic deformation binocular measurement system of a composite material propeller model, and relates to the technical field of propeller testing. The system comprises two cameras, white light stroboscopic light source equipment, a synchronizer, a software system, optical auxiliary equipment, a target and a dynamometer; the two cameras are arranged beside an observation window in the side of a water drum test section; the white light stroboscopic light source equipment is arranged at an observation window in the upper portion of the water drum test section; the synchronizer is connected with the cameras, the software system and the dynamometer and controls synchronous work of the cameras, the software system and the dynamometer; the target is arranged at a to-be-tested area, and the two cameras shoot at least eight pairs of speckle images, at different positions and in different directions, of the target; the software system is in charge of collecting the speckle images and conducting subsequent correlation analysis; the optical auxiliary equipment is arranged on the observation window in the side of the water drum test section. According to the system, through non-contact optical measurement, the speckle images of blades are obtained, real-time deformation features of composite material blades are obtained correlation analysis, and thus guidance in design and optimization of the composite material propeller is achieved.
Owner:CHINA SHIP SCIENTIFIC RESEARCH CENTER (THE 702 INSTITUTE OF CHINA SHIPBUILDING INDUSTRY CORPORATION)

Three-dimensional reconstruction method of micro-amplitude waves on free liquid surface

The invention relates to a three-dimensional reconstruction method of micro amplitude waves of a free liquid surface. The three-dimensional reconstruction method is characterized by comprising the following steps of: arranging a reference image on the bottom surface of a laboratory tank; vertically and downwardly shooting images of the reference image underwater before and after liquid surface fluctuation from the upper side of the liquid surface by utilizing a camera or a digital CCD (Charge Coupled Device); with the image in the static water before fluctuation as a first frame image and theimage after liquid surface fluctuation as a second frame image, carrying out cross-correlation analysis by utilizing a particle image velocimetry technology to obtain the distortion quantity of the image after the liquid level fluctuation; obtaining the entire wave slope values of the free liquid surface through calculation of the distortion quantity; and obtaining the surface wave amplitude of the free liquid surface through the numerical integration of the wave slope values. According to the invention, a simple and effective whole measurement measure is provided for the minimum-amplitude fluctuation of the free liquid surface under a laboratory environment, meanwhile, the instantaneous whole fluctuation can be obtained. The invention has the advantages of simple equipment, convenience for operation, high application flexibility and low measurement cost.
Owner:中国船舶重工集团公司第七〇二研究所
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