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93 results about "Wavelet reconstruction" patented technology

LIBS spectrum noise reduction method, system and device based on adaptive threshold wavelet transform and storage medium

The invention relates to the technical field of laser spectrum detection, in particular to an LIBS (Laser-induced Breakdown Spectroscopy) spectrum noise reduction method, system and equipment based on adaptive threshold wavelet transform and a storage medium. Acquiring an original spectral signal of the laser-induced breakdown spectroscopy; performing five-layer multi-layer wavelet decomposition on the original spectral signal by adopting a db4 wavelet basis function to obtain a high-frequency coefficient and a low-frequency coefficient of each layer; calculating a noise intensity standard deviation based on the detail coefficient of the highest decomposition layer; dynamically determining the optimal value of the regulation factor through a double-layer optimization strategy combining a grid search method and a golden section iterative optimization method; constructing an adaptive threshold value based on the noise intensity standard deviation and the adjustment factor; carrying out threshold value processing on the high-frequency coefficient by adopting a self-adaptive threshold value; and performing wavelet reconstruction on the processed high-frequency coefficient and low-frequency coefficient, and outputting a denoised spectral signal. While the LIBS spectral signal-to-noise ratio is remarkably improved, the spectral feature form is completely reserved, and reliable technical support is provided for laser-induced breakdown spectroscopy detection in a complex industrial environment.
Owner:GUIZHOU POWER GRID CO LTD +1

STFT dimension transformation-based spiking neural network mechanical fault diagnosis method

The invention is applied to the field of mechanical fault diagnosis signal processing, and particularly provides a pulse neural network mechanical fault diagnosis method based on STFT dimension transformation, and the method comprises the steps: collecting a one-dimensional mechanical vibration signal, carrying out the wavelet decomposition, carrying out the wavelet reconstruction of a low-frequency component and a denoised high-frequency component, and carrying out the wavelet reconstruction of the low-frequency component and the denoised high-frequency component; obtaining a denoised one-dimensional vibration signal; performing short-time Fourier transform, and converting the time-frequency two-dimensional matrix into a time-frequency two-dimensional matrix; inputting the time-frequency two-dimensional matrix into an improved HH threshold neuron model, carrying out Poisson sparse coding on the time-frequency two-dimensional matrix, and only carrying out pulse response on signal significant features; constructing a suprathreshold coding convolutional network with residual connection, inputting a sparse coding matrix, training by adopting an unsupervised learning rule based on STDP, and adaptively adjusting a network synaptic weight; and inputting to a trained above-threshold coding convolutional network, and obtaining pulse emission activity of neurons of an output layer through network forward propagation to determine a fault diagnosis result.
Owner:WESTLAKE INSTITUTE FOR OPTOELECTRONICS

Electric leakage detection method based on wavelet transform harmonic suppression

The invention discloses an electric leakage detection method based on wavelet transform harmonic suppression, and the method comprises the steps: synchronously collecting a current signal through a dual-channel differential sampling circuit, and obtaining two paths of differential voltages; after common-mode interference is eliminated through differential amplification and impedance matching, low-pass filtering and digital conversion are carried out; extracting signal multi-scale energy characteristics by using wavelet decomposition, and setting a threshold value to separate leakage low-frequency components from high-frequency noise; a pure electric leakage signal is obtained through inverse wavelet reconstruction, and a high-speed switching circuit compares a preset threshold value to trigger a protection action. According to the scheme, differential sampling, impedance matching and wavelet analysis technologies are combined, the signal-to-noise ratio and the detection precision are effectively improved, the problems that in the prior art, electric leakage signals are prone to interference and slow in response speed are solved, and the reliability and the real-time performance of electric leakage protection are remarkably improved.
Owner:HUANGBANG CHUANGKE (HUIZHOU) INTELLIGENT TECH CO LTD

Insulator image enhancement method based on unmanned aerial vehicle infrared image denoising

The invention relates to the technical field of image processing, in particular to an insulator image enhancement method based on unmanned aerial vehicle infrared image denoising. The method comprises the following steps: preprocessing an original infrared image acquired by an unmanned aerial vehicle, and performing multi-scale decomposition on the preprocessed image by using wavelet transform to obtain a high-frequency detail coefficient and a low-frequency approximation coefficient; a high-frequency detail coefficient is processed by adopting an adaptive threshold value, Wiener filtering is carried out on a low-frequency approximation coefficient, and a de-noised image is obtained after wavelet reconstruction and guide filtering processing; based on the de-noised image, an edge detection operator is adopted to perform preliminary edge extraction, non-maximum suppression and dual-threshold processing are combined to obtain edge information, and a morphological edge reconstruction technology is adopted to connect edge gaps; and generating a final image after feature enhancement through adaptive contrast enhancement based on local temperature distribution and image fusion processing. According to the invention, efficient denoising and accurate feature enhancement of the insulator infrared image collected by the unmanned aerial vehicle can be realized.
Owner:STATE GRID SHANGHAI MUNICIPAL ELECTRIC POWER CO

Drill rod fatigue crack ultrasonic weak signal enhancement method based on sparse wavelet reconstruction

The invention relates to a drill rod fatigue crack ultrasonic weak signal enhancement method based on sparse wavelet reconstruction, and belongs to the field of drill rod crack nondestructive testing. A multi-array-element ultrasonic data test is adopted for detecting the defect state of the drill rod, target features are enhanced through wavelet denoising result analysis, and crack recognition features are obtained based on a self-adaptive threshold value. The method comprises the following steps: carrying out wavelet decomposition and threshold processing on a detected signal, removing a noise signal, and reconstructing a wavelet coefficient of each layer after decomposition so as to obtain a de-noised ultrasonic detection signal. According to the method, the problem of weak crack signal decoupling under the strong noise background is solved, and accurate positioning and quantitative evaluation of the root defect of the drill rod thread are realized, so that the reliability of coal mine underground drill rod microcrack detection is improved, and a core technical support is provided for constructing an intelligent gas extraction safety monitoring system.
Owner:CHINA COAL TECH & ENG GRP CHONGQING RES INST CO LTD

Edge-guided adaptive fusion remote sensing image change detection method based on spatial frequency domain interaction

The invention discloses an edge-guided self-adaptive fusion remote sensing image change detection method based on spatial frequency domain interaction. The method comprises the following steps: preparing data of front and rear remote sensing images and real change labels; preprocessing based on the previous and later remote sensing images and labels to obtain a standardized data set; an edge-guided adaptive fusion network based on spatial frequency domain interaction is constructed, feature enhancement is carried out through a spatial and frequency double-branch structure, and an adaptive orthogonal fusion module is designed to carry out multi-construction interactive fusion on double-time features. Introducing an edge driving wavelet reconstructor as an auxiliary supervision branch to guide the feature change region edge modeling capability; and finally, a high-precision change prediction map is generated by inputting a double-time-phase remote sensing image. The method aims at solving the problems that edge prediction details are insufficient and background noise is difficult to restrain in a traditional change detection technology, the detection performance is effectively improved, the advanced change detection performance is shown on a data set, and the method has high competitiveness and practical value.
Owner:SHIHEZI UNIVERSITY

Cloud resource usage prediction method and system based on wavelet and attention mechanism

The invention discloses a cloud resource use prediction method and system based on wavelets and an attention mechanism. The method comprises the following steps: firstly, acquiring a multi-dimensional resource use sequence of a target server and dividing the multi-dimensional resource use sequence into a training subset and a test subset; generating an input sample set by adopting a sliding window mechanism; then constructing a cloud resource prediction model comprising a wavelet attention network, a multi-attention module, a wavelet reconstruction module and a memory enhancement self-attention module; decomposing the time window sample into a low-frequency feature component and a high-frequency feature component through a wavelet attention network; respectively generating a low-frequency feature vector and a high-frequency feature vector by using a multiple attention module; fusing into a reconstructed sample sequence through a wavelet reconstruction module; generating enhanced feature representation through a memory enhanced self-attention module; and finally, outputting a cloud resource use prediction sequence in a future time period through a full-connection projection layer. According to the method, the multi-frequency-domain time sequence characteristics can be effectively separated, the interaction relationship among the multi-element resources can be modeled, and the prediction precision and generalization ability are remarkably improved.
Owner:武夷学院

Insulator image enhancement method based on unmanned aerial vehicle infrared image denoising

The present application relates to the technical field of image processing, in particular to an insulator image enhancement method based on infrared image denoising of a UAV. The original infrared image collected by the UAV is preprocessed, and the preprocessed image is decomposed in multiple scales by wavelet transform to obtain high-frequency detail coefficients and low-frequency approximation coefficients; the high-frequency detail coefficients are processed by adaptive thresholding, while the low-frequency approximation coefficients are subjected to Wiener filtering, and after wavelet reconstruction and guided filtering, a denoised image is obtained; based on the denoised image, an edge detection operator is used for preliminary edge extraction, edge information is obtained by combining non-maximum suppression and double thresholding, and the edge gap is connected by using morphological edge reconstruction technology; through adaptive contrast enhancement based on local temperature distribution and image fusion processing, the final image with enhanced features is generated. The present application can realize efficient denoising and accurate feature enhancement of the insulator infrared image collected by the UAV.
Owner:STATE GRID SHANGHAI MUNICIPAL ELECTRIC POWER CO

Power distribution network fault traveling wave polarity discrimination method

The invention belongs to the field of power distribution network fault detection, and provides a power distribution network fault traveling wave polarity discrimination method, which comprises the steps of wavelet decomposition, threshold value processing, wavelet reconstruction, differential absolute value calculation, filtering threshold value calculation, first maximum point extraction and polarity determination. According to the method, polarity judgment is performed by comparing the data subjected to wavelet denoising and differential processing with 0, so that the influence of the non-stationarity of the original data on the waveform polarity can be effectively eliminated, and the polarity judgment accuracy is improved.
Owner:SICHUAN HUIYUAN OPTICAL COMM CO LTD +1

An improved wavelet denoising method based on the Sagnac fiber optic acoustic sensing system

The present invention discloses an improved wavelet denoising method based on a Sagnac fiber acoustic sensing system. The method includes: acquiring an original sound signal; decomposing the original sound signal by using a wavelet denoising method to obtain a decomposed sound signal; filtering the decomposed sound signal by using an improved wavelet threshold denoising algorithm, and then performing wavelet reconstruction to obtain a filtered noisy sound signal; and performing low-pass filtering on the filtered noisy sound signal to obtain a noise-reduced sound signal. The present invention can improve the quality of the acquired sound signal.
Owner:NANCHANG HANGKONG UNIVERSITY

Low Dry-Noise Ratio Interference Detection Method and Location Method Based on Multi-Beam Dual-Star System

The present invention discloses a low dry-to-noise ratio interference detection method and a positioning method based on a multi-beam double-star system, including: determining the interference frequency according to the main satellite interference, and establishing an interference model of the main satellite interference and the secondary satellite interference based on this; performing matched filtering on the interference forwarded by the two multi-beam satellites to the ground receiving station to improve the dry-to-noise ratio between the interferences; performing wavelet decomposition on the interference after matched filtering to obtain wavelet coefficients of different scales and frequencies; then determining a threshold, performing threshold processing on the wavelet coefficients to remove the noise coefficients and retain the interference coefficients. Using the retained interference coefficients for wavelet reconstruction to obtain the denoised interference. The present invention breaks through the double-star positioning limitation condition that the double stars need to jointly cover the interference source, and can realize the positioning of the interference source in a vast area, providing an effective tool for the positioning and troubleshooting of the interference source in the multi-beam satellite communication system.
Owner:NANJING UNIV OF POSTS & TELECOMM

Multi-energy consumption data completion method based on wavelet decomposition and Fourier transform

The present invention discloses a multi-energy consumption data completion method based on wavelet decomposition and Fourier transform, which includes the following steps: 1. performing wavelet decomposition on the collected carbon-containing characteristic energy consumption sequence to obtain an energy consumption cycle characteristic sequence and an energy consumption trend characteristic sequence; 2. obtaining a predicted energy consumption trend characteristic sequence based on curve fitting; 3. obtaining a predicted energy consumption cycle characteristic sequence based on Fourier series fitting; and 4. completing missing data through wavelet reconstruction based on steps 2 and 3. The present invention constructs a data completion model based on wavelet decomposition and Fourier transform, thereby enabling the completion of massive multi-energy consumption data for key emission-controlled enterprises.
Owner:STATE GRID ANHUI ELECTRIC POWER CO LTD ELECTRIC POWER SCI RES INST +1

Method and device for engraving tiny fracture geologic body, electronic equipment and medium

The invention belongs to the technical field of petroleum and natural gas exploration and development, and discloses a method and a device for engraving a tiny fracture geologic body, electronic equipment and a medium, the method for engraving the tiny fracture geologic body comprises the following steps: based on a multi-wavelet decomposition result, carrying out wavelet energy optimization sorting and stripping a strong energy quantum wave, and then completing multi-wavelet reconstruction; seismic signals related to the tiny fracture system are highlighted, and the spatial form of the tiny fracture geologic body is obtained through engraving. The method effectively improves the spatial form engraving precision of the tiny fractured geologic body, and is suitable for spatial engraving of the tiny fractured geologic body.
Owner:CHINA NAT PETROLEUM CORP +1

Baseline Removal Method for Multi-channel Magnetocardiogram Signals Based on Wavelet Low-Frequency Reconstruction and Morphological Secondary Smoothing

This invention discloses a baseline removal method for multi-channel magnetocardiogram (MCC) signals based on wavelet low-frequency reconstruction and morphological secondary smoothing. The invention includes: acquiring multi-channel MCC signal data; performing power frequency notch filtering on each channel to suppress the power frequency fundamental frequency and at least one harmonic component; performing configurable IIR low-pass filtering on the notched signal; setting a discrete wavelet transform extension mode and performing discrete wavelet decomposition on the filtered signal; selectively retaining decomposition coefficients based on the retention layer set and setting the remaining coefficients to zero, then performing inverse wavelet reconstruction to obtain an initial baseline estimate; performing morphological secondary smoothing on the median-smoothed baseline signal to obtain a corrected baseline signal; subtracting the corrected baseline signal from the filtered signal to obtain the baseline-corrected channel signals; and assembling and outputting a multi-channel baseline-corrected signal matrix. This invention can improve the stability and cross-channel consistency of baseline estimation for multi-channel MCC signals, reduce the risk of over-correction and under-correction, and is applicable to multi-channel batch processing scenarios.
Owner:BEIHANG UNIV

A cascaded anti-interference circuit suitable for an electrocardio monitoring device

The embodiment of the application provides a cascade anti-interference circuit suitable for an electrocardio monitoring device, which comprises a sliding mean filter module, a notch filter module, a lifting wavelet decomposition module, a threshold calculation module, a threshold processing module and a lifting wavelet reconstruction module; while ensuring a small circuit scale, the ECG signal collected by the wearable electrocardio monitoring device is subjected to hierarchical noise reduction processing, and high signal-to-noise ratio ECG signal output is realized; for the ECG signal collected by the wearable electrocardio monitoring device, first, sliding mean filtering is performed to filter out baseline drift noise caused by human respiratory movement and other activities; the power frequency interference caused by the wired and wireless connection of the electromagnetic environment around the device is suppressed by using the notch filter module; finally, wavelet noise reduction is realized by using the lifting wavelet decomposition and reconstruction and threshold noise reduction method, the electromyographic interference caused by the autonomous or unconscious movement of the wearer is suppressed, and high signal-to-noise ratio ECG signal is output, which is used for physiological parameter extraction and electrocardio diagnosis.
Owner:WUHAN KANGNUOXIN SEMICON CO LTD

A power load prediction method based on time-frequency enhancement and multi-level wavelet modeling

This invention provides a power load forecasting method based on time-frequency enhancement and multi-level wavelet modeling, comprising: constructing a multivariate historical power load time series and generating instance normalized sequences according to variable channels; performing time-domain enhancement and spectral enhancement on the instance normalized sequences to obtain enhanced feature sequences; performing multi-level discrete wavelet decomposition on the enhanced feature sequences to obtain a first-level approximation coefficient sequence and a detail coefficient sequence of wavelet coefficients at each level; performing independent resolution branch modeling based on the decomposition coefficient sequences, modeling and predicting the coefficient sequences corresponding to each resolution branch, obtaining predicted approximation coefficient sequences and predicted detail sequences at each level, and then performing multi-level wavelet reconstruction; and performing inverse normalization on the reconstruction results to obtain the power load forecasting results. Applying this method can coordinate time-domain and frequency-domain feature enhancement with multi-resolution modeling, improving the accuracy and stability of long-term power load forecasting while reducing computational complexity.
Owner:INFORMATION & COMMNUNICATION BRANCH STATE GRID JIANGXI ELECTRIC POWER CO

Cold test test denoising method and system based on wavelet threshold

This invention relates to a wavelet threshold-based method and system for denoising cold test vibrations, comprising the following steps: constructing a vibration parameter database based on the acquired diesel engine cold test vibration signal; performing wavelet decomposition on the vibration parameters in the database according to the selected wavelet basis function and decomposition level to obtain wavelet coefficients; performing wavelet reconstruction on the vibration parameters based on a threshold function to obtain denoised cold test vibration parameters, specifically: shrinking the wavelet coefficients within the threshold range to zero, while keeping the wavelet coefficients outside the threshold unchanged; and processing the acquired diesel engine cold test vibration signal using the denoised cold test vibration parameters to obtain a denoised cold test vibration signal. The threshold function is used to solve the oscillation and distortion problems existing in the denoising process, thereby improving the denoising effect of the cold test vibration signal.
Owner:SHANDONG UNIV

Image noise reduction method and device, equipment and medium

The invention discloses an image noise reduction method and device, equipment and a medium, which are used for realizing multi-channel wavelet high-frequency noise reduction. The method provided by the invention comprises the steps of performing wavelet decomposition on a to-be-denoised image to obtain a plurality of high-frequency components, and determining a plurality of high-frequency channel vectors; each high-frequency channel vector is obtained by combining high-frequency components of a plurality of channels of the to-be-denoised image at the same image coordinate position; for each high-frequency channel vector, determining a similar vector of the high-frequency channel vector, and generating a high-frequency similar vector matrix; on the basis of the high-frequency similar vector matrix, determining a parameter for performing noise reduction on the high-frequency channel vector; performing noise reduction processing on the high-frequency channel vector by using a parameter for performing noise reduction on the high-frequency channel vector to obtain a high-frequency channel vector after noise reduction; and on the basis of each denoised high-frequency channel vector, performing wavelet reconstruction by adopting a mode corresponding to wavelet decomposition to obtain a denoised image.
Owner:ZHEJIANG DAHUA TECH CO LTD

Current signal denoising method, system and storage medium for fault arc detection

The application discloses a current signal denoising method and system for fault arc detection and a storage medium, comprising: collecting the working current of the load at the current time, and analyzing to obtain the noise estimation spectrum of the working current at the current time; wavelet decomposing the noise estimation spectrum and the working current of the load at the subsequent time respectively to obtain first wavelet coefficients and second wavelet coefficients; correcting the second wavelet coefficients based on the first wavelet coefficients to obtain third wavelet coefficients; and wavelet reconstructing the third wavelet coefficients to obtain a time domain enhanced signal. The improved wavelet threshold function improves the defects of poor continuity and constant deviation of the traditional wavelet threshold function, and the current signal processed by the denoising algorithm not only suppresses the existence of noise, but also improves the arc characteristics of the signal, so that the detection performance of the fault arc detection algorithm is significantly improved.
Owner:INST OF ADVANCED TECH UNIV OF SCI & TECH OF CHINA +1

Cardiac mechanical signal processing method and device based on wavelet reconstruction

The invention discloses a cardiac mechanical signal processing method and device based on wavelet reconstruction. The method comprises the following steps: performing trend removal and frequency band extraction on an original SCG signal, and reserving main mechanical energy components corresponding to a heart sound event; then wavelet decomposition and main scale reconstruction are carried out, and time domain features of key components such as S1 and S2 structures similar to PCG signals are strengthened, so that heart sound-like signals which are similar to PCG in form and clear in rhythm are generated. Compared with an original SCG signal, the heart sound-like signal obtained through reconstruction is remarkably improved in the aspects of rhythm definition, form consistency and peak stability. And further performing rhythm analysis on the reconstructed signal, introducing physiological constraints, and screening to obtain a cardiac trigger point sequence, thereby realizing high-precision cardiac recognition. The device can be integrated with medical image equipment and wearable equipment, and the functions of heart sound gating, synchronous triggering or auscultation auxiliary analysis and the like are achieved.
Owner:HANGZHOU DIANZI UNIV

A method to combat main lobe interference based on signal separation

The present invention discloses a method for resisting mainlobe interference based on signal separation, comprising: performing de-skewing processing on an echo signal received by a radar system to obtain the real and imaginary parts of the de-skewing signal; performing L-layer wavelet decomposition on the real and imaginary parts of the de-skewing signal to obtain M sub-modes of the de-skewing signal; calculating the matching degree of the M sub-modes with the radar matching coefficient, and selecting the sub-mode corresponding to the target signal component; using the sub-mode corresponding to the target signal component as the mode to be reconstructed, and obtaining a reconstructed signal through wavelet reconstruction; performing an inverse de-skewing operation on the reconstructed signal to obtain a reconstructed echo signal. Aiming at the situation of low interference-to-signal ratio and low signal-to-noise ratio, the present invention divides the echo into interference and target components according to wavelet decomposition and retains the target component to reconstruct the echo, thereby removing the interference components entering the radar mainlobe, ensuring the integrity of the target information as much as possible, and reducing the energy loss of the target.
Owner:XIDIAN UNIV

A relay contact fault identification method based on wavelet denoising and support vector machine

The present application relates to the technical field of fault detection, and relates to a relay contact fault identification method based on wavelet denoising and a support vector machine, comprising the following steps: S1, constructing a current signal acquisition and double-channel reconstruction circuit: a Rogowski coil is sleeved on an output loop of a relay contact, and a differential voltage signal is inducted and output by the Rogowski coil; S2, respectively adopting a first wavelet base and a second wavelet base to perform multi-scale wavelet decomposition, threshold denoising and wavelet reconstruction on a complete current digital sequence and a transient current digital sequence; S3, extracting time domain statistical features from the complete current digital sequence after denoising, extracting time-frequency energy features from the transient current digital sequence after denoising, and outputting a fault category of the relay contact after classification and decision by a support vector machine classifier. The present application overcomes the inherent contradiction that a single acquisition channel is difficult to simultaneously consider slow-changing contact components and transient disturbance components in terms of dynamic range and denoising strategy.

Power load prediction method and system based on multi-stage time sequence preprocessing and double-branch wavelet Mamba

The application discloses a power load prediction method and system based on multi-stage time sequence preprocessing and double-branch wavelet Mamba, and relates to the technical field of intelligent power grids and time sequence analysis. In view of the problems that the existing power load prediction technology has insufficient long sequence modeling capability, low prediction robustness and precision, and cannot simultaneously consider global trend fitting and local mutation capturing when facing high-noise non-stationary data, a high-quality target sequence is first constructed through multi-stage time sequence preprocessing, and after channel independence and block embedding processing, the high and low frequency characteristic components are decoupled through discrete wavelet transform, the global long-range dependence is extracted through a bidirectional trend Mamba module, the local mutation characteristics are purified through a detail Mamba module, and noise is suppressed, and finally, the prediction result is output through inverse wavelet reconstruction. The application significantly improves the precision and robustness of long sequence power load prediction and reduces the computational complexity.
Owner:JIANGNAN UNIV

Hybrid model-based wind power medium-and-long-term generating capacity prediction method and device

PendingCN121480794AGeneration forecast in ac networkForecastingAlgorithmMultilayer perceptron neural network
The invention discloses a hybrid model-based wind power medium-and-long-term generating capacity prediction method and device, and belongs to the technical field of wind power generation. The method comprises the following steps: acquiring historical actually measured wind power data and historical meteorological data as input, and obtaining a cleaned power generation time sequence; performing discrete wavelet decomposition on the cleaned power generation time sequence to obtain multiple layers of subsequences of different frequency bands; based on the sub-sequence and the historical meteorological data, selecting an optimal prediction feature subset from the data; constructing a plurality of multi-level perceptron neural network models running in parallel, and outputting corresponding prediction results; and performing wavelet recombination on all the output prediction results to obtain a final prediction value of the medium-and-long-term generating capacity of the wind power. According to the technical scheme, high-precision prediction of the medium-and-long-term generating capacity of wind power is achieved, abnormal data can be effectively removed, multi-scale features are extracted, multi-model collaborative learning is achieved, and the reliability and adaptability of a prediction result are improved.
Owner:中国船舶集团风电发展有限公司 +1

Ultrasonic sensor field calibration signal denoising method based on improved VMD-wavelet

The invention discloses an ultrasonic sensor field calibration signal denoising method based on improved VMD-wavelet. When a partial discharge ultrasonic sensor is verified on site, a verification signal output by the ultrasonic sensor comprises narrow-band noise and white noise. In order to suppress the two kinds of noise, firstly, an original noisy signal output by the ultrasonic sensor to be detected is collected and decomposed by using VMD to obtain IMF components, secondly, the IMF components containing narrow-band signals are screened out based on a kurtosis joint correlation coefficient criterion and removed, effective IMF components are reserved, the effective IMF components are decomposed by adopting discrete wavelet transform, and then the two kinds of noise are suppressed. And processing the high-frequency detail coefficient by using an improved threshold criterion and a self-adaptive threshold function, and finally performing wavelet reconstruction on each layer of coefficient after processing through wavelet inverse transformation to obtain a de-noised signal. According to the method, adaptive denoising can be carried out on narrow-band noise and white noise, and the algorithm efficiency is high.
Owner:CHINA UNIV OF MINING & TECH

A wavelet denoising method and system for SAR image and electronic equipment

The application discloses a wavelet denoising method and system for SAR images and electronic equipment, and relates to the technical field of remote sensing image processing. The method comprises the following steps: determining a wavelet and a wavelet decomposition level, and calculating a wavelet coefficient matrix obtained by wavelet decomposition of a to-be-processed SAR image; determining an initial adaptive threshold and a corresponding estimated wavelet coefficient matrix according to the wavelet coefficient matrix based on a preset adaptive threshold estimation function; removing a wavelet coefficient when any wavelet coefficient is less than the initial adaptive threshold; when any wavelet coefficient is greater than or equal to the initial adaptive threshold, constructing a risk function based on the wavelet coefficient and the estimated wavelet coefficient matrix; performing minimum calculation on the risk function based on a minimum maximum estimation criterion to obtain optimal wavelet coefficients after threshold processing; and performing wavelet reconstruction on the optimal wavelet coefficients to obtain a denoised SAR image. The application effectively removes noise in the image while better maintaining the image edge, thereby improving the denoising effect.
Owner:NO 63921 UNIT OF PLA

Image noise reduction method and device, equipment and medium

The invention discloses an image noise reduction method and device, equipment and a medium, which are used for improving an image noise reduction effect. The method provided by the invention comprises the steps of obtaining a to-be-denoised image, and performing wavelet decomposition on the to-be-denoised image to obtain a wavelet decomposition result which comprises a low-frequency component and a high-frequency component; carrying out pixel point clustering on the to-be-denoised image to obtain at least one cluster; for each cluster, based on a wavelet decomposition result, determining a corresponding relation between a brightness value and a noise estimation value of at least one pixel point of the cluster; determining a noise reduction threshold value corresponding to the cluster based on the pixel value of each pixel point of the cluster and the corresponding relationship; performing noise reduction processing on the high-frequency component of each pixel point of the cluster by using the noise reduction threshold value corresponding to the cluster; and performing wavelet reconstruction based on the low-frequency component of each cluster and the high-frequency component after noise reduction processing to obtain an image after noise reduction processing.
Owner:ZHEJIANG DAHUA TECH CO LTD

Gyro signal denoising method based on kalman filtering and visushrink threshold processing

The present application relates to a gyro signal denoising method based on Kalman filtering and Visushrink threshold processing, comprising the following steps: establishing a time series model of a gyro signal; using adaptive anti-outlier Kalman filtering to denoise the gyro signal; using wavelet analysis to respectively perform Visushrink threshold processing on low-frequency components and high-frequency components of the Kalman filtered gyro signal; and performing wavelet reconstruction on the high-frequency and low-frequency signals of the threshold processed gyro signal. The present application provides an adaptive anti-outlier denoising scheme for gyro signals, which combines Kalman filtering and wavelets, can more effectively improve the accuracy of sensors and reduce errors.
Owner:CHINA THREE GORGES UNIV

Fault diagnosis method for aircraft executing mechanism

The invention discloses a fault diagnosis method for an aircraft executing mechanism. The fault diagnosis method comprises the following steps: collecting a motor signal of the aircraft executing mechanism; sequentially carrying out wavelet decomposition, threshold processing, wavelet reconstruction and denoising preprocessing to obtain denoised motor current one-dimensional data; constructing a fault diagnosis model, wherein the fault diagnosis model comprises a convolutional neural network CNN layer, a long short-term memory network LSTM layer, a channel attention mechanism and a full connection layer; inputting the motor current one-dimensional data into a convolutional neural network (CNN) layer and a long short-term memory (LSTM) layer, applying a channel attention mechanism on the LSTM layer, and performing weight scoring on the output of the LSTM layer to obtain a trained fault diagnosis model; and carrying out aircraft fault detection on the test set by using the trained fault diagnosis model to obtain a fault diagnosis result. According to the method, online learning can be realized, new and unknown fault modes can be immediately adapted, and dependence on historical fault data is reduced.
Owner:SHANGHAI JIAOTONG UNIV

Offshore culture video identification method and device based on spectrum semantic consistency

The invention discloses an offshore culture video identification method and device based on spectrum semantic consistency. The method comprises the following steps: receiving underwater video data of an offshore culture scene, and carrying out time sequence alignment and steady-state preprocessing on the underwater video data to obtain a steady-state frame sequence; frequency domain enhancement processing is carried out on the steady-state frame sequence, the processing comprises wavelet decomposition, sub-band residual refinement based on historical statistical reference and wavelet reconstruction, and the processing logic is optimized by the spectrum-semantic quality consistency constraint introduced in the training stage; and finally, inputting the enhanced image sequence into a pre-trained multi-task neural network for feature extraction and semantic recognition, and outputting a recognition result. According to the invention, through a collaborative optimization mechanism of frequency spectrum and semantics, in combination with a quality-gated self-learning framework and a cost-driven deployment strategy, the recognition accuracy, robustness and system adaptability of an offshore culture video in a complex underwater environment are significantly improved.
Owner:JIMEI UNIV +1