Patents
Literature
Patsnap Copilot is an intelligent assistant for R&D personnel, combined with Patent DNA, to facilitate innovative research.
Patsnap Copilot

114 results about "Multi resolution analysis" patented technology

Method for extracting rim ultrasonic flaw detection signal on the basis of wavelet transformation

The invention discloses a method for extracting rim ultrasonic flaw detection signals on the basis of wavelet transformation, and particularly relates to an effective signal identifying method provided aiming at complex discrete signals collected by an online automatic flaw detection device for a locomotive wheel on an industrial site. The method mainly comprises the following steps of loading collected initial data, carrying out wavelet multi-resolution analysis to original signals, carrying out threshold value processing to each layer coefficient obtained after the wavelet transformation, and then inversely transforming wavelet coefficient to reconstruct signals. After the denoising is accomplished, the effective signals can extract positive detection enveloping curves so as to read flaw detection reports to be displayed in a user interface. Compared with the traditional digital filter in the aspect of extracting effective signals, the method has the advantages that the loss of an echo peak value is small, thus the defect detection rate is greatly enhanced, and the false dismissal possibility is avoided; and the denoising effect is obvious, and the effective signals are smooth, thus pulse signals can be effectively extracted from high-frequency noise, so as to avoid the possibility of false detection.
Owner:NANJING TYCHO INFORMATION TECH

Lightning stroke fault identification method and system

The invention relates to a lightning stroke fault identification method and system. The lightning stroke fault identification method comprises the following steps of reading valid fault waveform information in a local database, performing wavelet transform multi-resolution analysis on the valid fault waveform information, and obtaining a fault waveform; analyzing the frequency of the fault waveform to obtain a ratio of the wavelet energy of the transient current additional component of the fault waveform at a preset high-frequency band to the wavelet energy of the transient current additional component of the fault waveform on a preset low-frequency band; according to the ratio of the wavelet energy, identifying whether the line fault type of a transmission line is non-fault lightning stroke to obtain an identification result; if the identification result is indicative of no, obtaining the energy distribution characteristic data of the fault waveform; according to the energy distribution characteristic data, identifying the line fault type of the transmission line is fault lightning stroke or ordinary short-circuit fault. The method and system can improve the utilization rate of fault information and the accuracy rate of identification, and increase the identification rate of lightning fault type.
Owner:QINZHOU POWER SUPPLY BUREAU OF GUANGXI POWER GRID CO LTD

Multi-sensor image fusion method on basis of IICM (improved intersecting cortical model) in NSST (nonsubsampled shearlet transform) domain

InactiveCN103295201AFusion processingImage enhancementMulti resolution analysisSource image
The invention discloses a multi-sensor image fusion method on the basis of an IICM (improved intersecting cortical model) in an NSST (nonsubsampled shearlet transform) domain. The multi-sensor image fusion method includes: step 1, building the IICM; step 2, inputting all the multi-sensor source images to be fused to perform NSST and acquiring one low-frequency sub-band image and multiple high-frequency sub-band images from each multi-sensor source image to be fused; step 3, importing all the high-frequency sub-band images and the low-frequency sub-band images into the IICM to complete fusion of the low-frequency sub-band images and fusion of the high-frequency sub-band images; step 4, performing NSST inverse transformation on the high-frequency sub-band images and the low-frequency sub-band images which are fused finally to acquire the final fusion image. The improved model, namely the IICM is provided on the basis of the classical ICM, multi-resolution analysis of the multi-sensor source images and reconstruction of the finally fused image are completed by means of NSST, and problems about fusion of the multi-sensor images are solved reasonably since the IICM is utilized for realizing fusions of the high-frequency sub-band images and the low-frequency sub-band images.
Owner:ENG UNIV OF THE CHINESE PEOPLES ARMED POLICE FORCE

Positioning method of plurality of same-frequency radiation sources based on field intensity

The invention discloses a positioning method of a plurality of same-frequency radiation sources based on field intensity, which belongs to the field of spectrum management. The method is based on the field intensity of a certain frequency channel measured by a vehicle-mounted omnidirectional antenna and longitude and latitude data measured by a GPS (Global Position System). The field intensity data are arrayed according to the measurement sequence, wavelet multi-resolution analysis is used to remove the noise caused by fast fading in the field intensity; and then latitude / longitude coordinates corresponding to the maximum value point are found out; the maximum value point is divided into different areas by a clustering algorithm; and at last, each estimated source point in the area and useable detected points in the area are calculated by an Egli model formula to obtain an absolute mean of difference array elements, so that the position of the source point in the area is determined. The positioning method disclosed by the invention is the positioning under a passive direction finding condition, the reliability is rather high, and the positioning method has a wide practical value and application prospect in the field of the spectrum management.
Owner:BEIHANG UNIV

Medical ultrasound image registration method based on integer lifting wavelet multiresolution analysis

A non-rigid body image registering method, belongs to medicine ultrasonic image processing field. The invention provides a ultrasonic image registering method implemented by multi-resolution analysis and lamination based on integer lifting wavelet, directing towards the difficulty that the previous registering computation of non rigid body image is complicated and the requirement for memory is large. The registration image is subjected to two-layer decomposition using integer lifting wavelet and then the decomposed approximate image is subjected to overall rigid body registration of low resolution, furthermore the registered image is subjected to image reconstruction of original resolution using integer lifting wavelet, finally the local non-rigid body registration is performed at the original image resolution, therefore the final registered image is obtained. The method of multi-resolution analysis based on integer lifting wavelet can reduce the amount of calculation and the computation complexity and registration accuracy are unified using the method of multi-layer decomposition and fine and rough combination, therefore the amount of calculation is reduced without reducing the registration accuracy. The non-rigid body image registering method has wide application prospect in ultrasound imaging field.
Owner:HARBIN INST OF TECH

Online identification and visualization method for power grid disturbances based on multi-resolution wavelet analysis

The invention relates to an online identification and visualization method for power grid disturbances based on multi-resolution wavelet analysis, which belongs to the technical field of wide-area dynamic monitoring and visualization of power systems. The method comprises the following steps: carrying out offline simulation analysis on the features of typical dynamic disturbance accidents in power grid, and selecting a wavelet function Psi and the decomposition layer-number I corresponding to the obtained maximum wavelet coefficient energy as online wavelet multi-resolution analysis tools; carrying out regionalization according to the PMU (power management unit) configuration situation of a target power grid, so that each region has one and only one PMU substation for measurement, and transmitting frequency signals measured by each PMU substation to a WAMS (wide area measurement system) master station; acquiring frequency signals of each PMU substation from the WAMS master station, and carrying out I-layer online wavelet multi-resolution analysis on the frequency signals by using the determined wavelet function so as to obtain wavelet coefficients of an I(th) layer; and discriminating disturbance occurrence time, disturbance occurrence potion and disturbance type according to the wavelet coefficients; and carrying out visualized display through taking a map as the background. The method disclosed by the invention can improve the running reliability of an electrical power grid.
Owner:TSINGHUA UNIV +1

Image splicing method based on projection geometry and SIFT characteristics

The invention discloses an image splicing method based on projection geometry and SIFT characteristic matching point pairs. According to the method, firstly, two images with overlapping areas are captured, SIFT characteristic points are extracted from to-be-spliced images, characteristic point matching is carried out through the K-D tree search algorithm, the RANSAC algorithm is further utilized to carry out characteristic point purification to eliminate wrong matching point pairs, a transformation matrix is calculated if the number of characteristic matching point pairs after purification isgreater than 8, if the number of characteristic matching point pairs after the purification is less than 8, the corresponding number of projection matching point pairs are extracted according to the known overlapping areas of the two images to complete the 8 pairs of matching points, a transformation matrix is calculated, image registering is completed, image fusion is carried out through employing the multi-resolution analysis method for the images after registering, and lastly, the spliced image is outputted. The method is advantaged in that a problem of image registration failure due to thefewer pairs of characteristic matching points can be solved through image splicing, and the image splicing effect is excellent.
Owner:CENT SOUTH UNIV

Ecological water supplement technology for lakes based on multi-scale wavelet transform

The invention relates to ecological water supplement technology for lakes based on multi-scale wavelet transform, which is characterized by not only well extracting the information of the water level on different scales by applying the excellent performance of multi-resolution analysis of wavelet transform but also reconstructing the wavelet coefficients of main scales and combining other hydrological and ecological data to obtain the division standards of hydrological stages, determining the suitable hydrological stage containing the wet and dry seasons and putting forward a scheme of ecological water supplement for lakes, which simultaneously takes both the minimum ecological water level and the in-year water level fluctuation characteristic into account. Compared with the prior art, the invention is characterized by more deeply discussing the multi-scale characteristic of hydrology, being closer to the natural hydrological conditions of lakes than the single minimum ecological water level of traditional water supplement and providing bases for analyzing the state of the hydrological environment of degraded wetlands, formulating water supplement schemes suitable for specific regions and improving efficiency of water supplement for lakes.
Owner:BEIJING NORMAL UNIVERSITY

Particle swarm optimization-based multi-resolution wavelet neural network power consumption prediction method

The invention relates to a particle swarm optimization-based multi-resolution wavelet neural network power consumption prediction method, and belongs to the field of neural network prediction research. According to the technical scheme, the method involves contents such as a wavelet neural network, a particle swarm optimization-based wavelet neural network and a particle swarm optimization-based multi-resolution wavelet neural network; the wavelet neural network, a particle swarm algorithm and multi-resolution analysis are combined; and high efficiency of the prediction method is verified by predicting power consumption. The feasibility and high efficiency of the prediction method are verified specifically through a simulation experiment: a wavelet neural network prediction method, a particle swarm optimization-based wavelet neural network prediction method and a particle swarm optimization-based multi-resolution wavelet neural network prediction method are compared. A target function and a regression analysis graph obtained by analysis can clearly show that by adopting the last prediction method, a target function value is converged more quickly, the prediction precision is higher, the influence caused by crossed overlapping of neurons in a hidden layer is effectively avoided, falling into local minimum is avoided, and the prediction effect is better.
Owner:STATE GRID JIBEI ELECTRIC POWER CO LTD TANGSHAN POWER SUPPLY CO +1

Microgrid inverter fault diagnosis method based on wavelet transformation and probabilistic neural network

PendingCN110084106AStrong ability to addEase of engineering integrationElectrical testingCharacter and pattern recognitionMulti resolution analysisMicrogrid
The invention provides a microgrid inverter fault diagnosis method based on wavelet transformation and a probabilistic neural network. The method comprises the steps that firstly, building a fault simulation system of the microgrid inverter on simulation software, then collecting three-phase load currents under different fault types to serve as measurement signals, and extracting fault characteristic signals of the three-phase load currents through a wavelet multi-resolution analysis method; carrying out normalization processing on the extracted fault feature signal to construct a feature vector; and finally, selecting a part of the extracted fault feature vectors as training data to train the PNN model, and when a genetic algorithm is adopted to find an optimal smoothing factor of the probabilistic neural network, and when the inverter has a fault, carrying out fault positioning on a current signal according to the method, thereby realizing fault diagnosis of the microgrid inverter. The method has the advantages that the structure model is simple, determination is easy, the convergence speed is high, a Bayes optimization solution is converged, the sample adding capacity is high, retraining is not needed, the precision is high, the practicability is high, and engineering combination is easy.
Owner:CHINA UNIV OF GEOSCIENCES (WUHAN)

Terahertz SAR high-frequency vibration error compensation method

The invention discloses a terahertz SAR high-frequency vibration error compensation method. Terahertz SAR imaging under high-frequency vibration has a pair of echo phenomena, firstly, according to a vibration geometric model of a terahertz SAR airborne platform, the influence of the platform vibration on the instantaneous slant distance of the SAR imaging is obtained, and a echo signal model underthe terahertz SAR high-frequency vibration is established; after the echo is subjected to the distance pulse pressure, the influence of the high-frequency vibration of the platform on the distance walking of the signal is analyzed, and the secondary phase position is introduced, and focusing of the pairing echo is completed by adopting the terahertz SAR high-frequency vibration imaging method based on doppler keystone transformation; and then a wavelet multi-resolution analysis is introduced to carry out platform vibration frequency estimation aiming at the relation between the phase of the imaging result and the vibration parameters of the platform, a vibration amplitude phase is estimated by combining a frequency estimation value with a parameter space projection method, and a phase compensation function is constructed to realize accurate compensation of the terahertz SAR high-frequency vibration error. According to the method, accurate compensation of the terahertz SAR high-frequency vibration error is realized, and the imaging quality of the actual terahertz SAR platform is improved.
Owner:SHANGHAI RADIO EQUIP RES INST
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products