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128results about How to "Easy to process in real time" patented technology

Self-adaptive low-illuminance or non-uniform-brightness image enhancement method

The invention relates to a self-adaptive low-illuminance or non-uniform-brightness image enhancement method. The method comprises the following steps: 1), preprocessing is performed on a low-illuminance and non-uniform-brightness image, wherein the preprocessing includes brightness preprocessing on the low-illuminance and non-uniform-brightness image, and edge enhancement is performed on the image after brightness preprocessing, so that the preprocessed image is obtained; 2), region segmentation is performed according to the brightness of the preprocessed image, corresponding mapping functions are selected according to the different characteristics of all segmented regions and corresponding self-adaptive brightness enhancement is performed; 3), saturation enhancement processing is performed on the image subjected to self-adaptive brightness enhancement segment by segment through the change characteristics of initial saturation and brightness. According to the invention, the steps are adopted to process the image, therefore, the color saturation of the image is improved, the image is enabled to be bright in color and have a better visual effect. The self-adaptive image enhancement method can be widely popularized in the fields of biomedicine, real-time monitoring, satellite remote sensing and the like.
Owner:DALIAN UNIV OF TECH

Multi-target positioning method of bistatic multi-input multi-output radar

The invention provides a multi-target positioning method of a bistatic multi-input multi-output radar, comprising the following steps of: (1) transmitting mutually orthogonal phase-coded signals by M transmitting array elements, and receiving the phase-coded signals by N receiving array elements, wherein the distances of the M transmitting array elements and the N receiving array elements are all of half wavelengths; (2) carrying out matched filtering on the received phase-coded signals by a matched filter of a receiver of each receiving array element; (3) carrying out multistage Wiener filtering on a matched signal data covariance matrix space, and carrying out forward recursion to obtain a signal subspace; (4) carrying out high-resolution DOA (Direction of Arrival) estimation by using an ESPRIT algorithm, wherein a pairing algorithm is used for carrying out the automatic pairing on two-dimensional parameters; and (5) realizing multi-target positioning according to cross points at two angles so as to obtain the positions of space targets. The multi-target positioning method provided by the invention has the advantages of low computation complexity, high computation speed, high estimation accuracy and can be used for positioning the sea-surface or low-altitude targets during tracking and guidance.
Owner:HARBIN ENG UNIV

Multiple-target and send-receive angle estimation method of double-base multiple-input and multiple-output radar

The invention provides a multiple-target and send-receive angle estimation method of a double-base multiple-input and multiple-output radar. A receiving end collects echo signals of every receiving antenna through an analog to digital (A/D) sampling module. The collected signals passes through a matched filter group, signals corresponding to every launching channel are separated, and receiving data of a virtual array is obtained, wherein the number of array elements is MN. The receiving data is expanded and is transformed into a real number field by utilizing Unitary transformation. A covariance matrix is calculated and is disassembled by utilizing characteristic value to obtain an actual value signal subspace and an actual value signal subspace. In the end, a target DOD is obtained by utilizing Unitary ESPRIT, and a target DOA is obtained by utilizing Unitary Root-MUSIC. According to the multiple-target and send-receive angle estimation method of the double-base multiple-input and multiple-output radar, the send-receive angle is automatically paired, extra pairing operation is not needed, and cross bearing of the target is achieved by utilizing the send-receive angle of the target. The multiple-target and send-receive angle estimation method of the double-base multiple-input and multiple-output radar has the advantages of being high in estimated accuracy and low in computing complexity.
Owner:HARBIN ENG UNIV

Relevance vector machine-based multi-class data classifying method

InactiveCN102254193AAvoid Category OverlapAvoid approximationCharacter and pattern recognitionValue setData set
The invention provides a relevance vector machine-based multi-class data classifying method, which mainly solves the problem that the traditional multi-class data classifying method cannot integrally solve classifying face parameters and needs proximate calculation. The relevance vector machine-based multi-class data classifying method comprises a realizing process comprising the following steps of: partitioning a plurality of multi-class data sets and carrying out a normalizing pretreatment; determining a kernel function type and kernel parameters; setting basic parameters; calculating the classifying face parameters; calculating lower bounds of logarithms and solving variant values of the lower bounds of the logarithms and adding 1 to an iterative number; if the variant values of the lower bounds of the logarithms are converged or the iterative number reaches iterating times, finishing updating the classifying face parameters, and otherwise, continuing to updating; and obtaining a prediction probability matrix according to the updated classifying face parameters, wherein column numbers corresponding to a maximum value of each row of the matrix compose classifying classes for testing the data sets, and samples which have the prediction probability less than a false-alarm probability and the detection probability corresponding to a false-alarm probability value set in a curve are rejected. The relevance vector machine-based multi-class data classifying method has the advantages of obtaining classification which is comparable to that of an SVM (Support Vector Machine) by using less relevant vectors and rejecting performance and can be used for target recognition.
Owner:XIDIAN UNIV

Low-complexity space target two-dimensional angle estimation method of L-shaped array MIMO radar

The invention aims to provide a low-complexity space target two-dimensional angle estimation method of L-shaped array MIMO radar. The method comprises the following steps that an L-shaped array is composed of two uniform linear arrays perpendicular to each other, the distance between every two adjacent array elements is a half of a wavelength, one linear array has M array elements, the other linear array has N array elements, all the array elements are receiving and sending co-located array elements, orthogonal narrow-band signals are sent, received signals are processed by means of matched filtering, and echo signals of a large-aperture virtual array are obtained; a dimensionality reduction array is designed, and dimensionality reduction is conducted on the echo signals; characteristic decomposition is conducted on a covariance matrix of dimensionality reduction signals, and a two-dimensional space spectrum function is obtained; a two-dimensional angle in the two-dimensional space spectrum function is decoupled, and space spectrum estimation is conducted on the angle of one dimension; an obtained space spectrum estimated value is substituted into the space spectrum function, and polynomial rooting estimation is conducted on the angle of the other dimension; according to the relation of trigonometrical functions, the azimuth angle and pitching angle of a target are obtained. The method greatly reduces computational complexity of algorithm, and is beneficial to real-time processing of a radar system.
Owner:HARBIN ENG UNIV

A positioning method of small unmanned aerial vehicle based on binocular vision

The invention discloses a positioning method of a small unmanned aerial vehicle based on binocular vision, which includes the following steps: using a ground target as a reference, selecting the target centroid as the origin of the navigation coordinate system, wherein the binocular camera fixed on the computer is based on the V4L2 interface to collect the image of the object in real time; By means of the object detection algorithm based on color model and artificial neural network algorithm to remove the disturbance region in the image, extracting the target area from the left and right viewsprecisely, the difference in the width of the target centroid pixel between the two images is the parallax of the target point; combined with binocular ranging and camera calibration parameters, theposition of the target point in the left camera coordinate system is calculated, and then the rotation matrix from the current airframe coordinate system to the initial airframe coordinate system is calculated based on the attitude angle information obtained by IMU, so as to calculate the coordinates of the UAV in the navigation coordinate system. The method effectively shortens the positioning time of the unmanned aerial vehicle (UAV) and is beneficial to the real-time processing of the aircraft position.
Owner:SOUTH CHINA UNIV OF TECH

Space-borne SAR image target positioning method capable of eliminating ground elevation errors

The invention discloses a space-borne SAR image target positioning method capable of eliminating ground elevation errors, comprising the following steps: (1) acquiring needed ephemeris parameters; (2) respectively calculating target slant-range parameters, Doppler parameters and state vectors of a satellite; (3) substituting the target slant-range parameters, the Doppler parameters and the state vectors in step (2) into a target positioning equations set, and then solving the equations set to obtain a ground target position; and (4) taking the x, y and z coordinates solved in step (3) as the coordinates under an inertial coordinate system, transforming the coordinates into a geocentric rotating coordinate system xc, yc and zc by a coordinate transformation mode, transforming the geocentric rotating coordinate system into geocentric longitude and latitude Lc and Deltac, and finally transforming the geocentric longitude and latitude into geographical longitude and latitude lon and lat. In the method, the target positioning equations set does not contain an earth model equation, thus eliminating positioning errors caused by the ground elevation errors, avoiding the difficult problem of solving a Range-Doppler (R-D) positioning equations set, and being beneficial to real-time processing of ground target positioning.
Owner:SHANGHAI UNIV

Restraining device and restraining method for burst impulse noise of power line communication channel

The invention discloses a restraining device and restraining method for burst impulse noise of a power line communication channel. The restraining device comprises a Fourier transformation module, a masking subcarrier selection module and a compressed sensing estimation module. The restraining method for the burst impulse noise of the power line communication channel is based on compressed sensing and comprises the steps of carrying out Fourier transformation on a received signal to obtain a frequency domain signal, carrying out masking subcarrier selection to obtain a subcarrier only comprising background noise and the burst impulse noise, estimating the burst impulse noise in the power line communication channel by using a signal recover method based on compressed sensing, and finally, removing the impulse noise from the received signal to obtain a signal with noise removed. Due to the facts that the burst impulse noise in the power line communication channel has the characteristic of sparsity, and the OFDM masking subcarrier selection and compressed sensing technologies are applied, the effect of restraining the noise can be remarkably improved, and signal information of positions interfered by burst impulse can be effectively kept.
Owner:DALIAN UNIV OF TECH

Defect detection system

Scattered radiation from a sample surface is collected by means of a collector that collects radiation substantially symmetrically about a line normal to the surface. The collected radiation is directed to channels at different azimuthal angles so that information related to relative azimuthal positions of the collected scattered radiation about the line is preserved. The collected radiation is converted into respective signals representative of radiation scattered at different azimuthal angles about the line. The presence and / or characteristics of anomalies are determined from the signals. Alternatively, the radiation collected by the collector may be filtered by means of a spatial filter having an annular gap of an angle related to the angular separation of expected pattern scattering. Signals obtained from the narrow and wide collection channels may be compared to distinguish between micro-scratches and particles. Forward scattered radiation may be collected from other radiation and compared to distinguish between micro-scratches and particles. Intensity of scattering is measured when the surface is illuminated sequentially by S- and P-polarized radiation and compared to distinguish between micro-scratches and particles. Representative films may be measured using profilometers or scanning probe microscopes to determine their roughness and by the above-described instruments to determine haze in order to build a database. Surface roughness of unknown films may then be determined by measuring haze values and from the database.
Owner:KLA CORP

Optimal active time-reversal focusing method based on iterative least square/pre-filtering

ActiveCN101645264ARealize inverse filter focusing in time domainEliminate focus blurAdaptive networkSound producing devicesSound sourcesSonification
The invention relates to an optimal active time-reversal focusing method based on iterative least square / pre-filtering. The method comprises the following steps: 1) sending source signals by a guide sound source, and conducting the operations of receiving, time-reversal and re-sending by a time-reversal array according to the conventional active time-reversal process, so as to acquire focusing signals at the location point of the sound source, wherein the source signals are wideband pulse signals with the bandwidth being 20Hz to 200kHz and the frequency range being within an audible sound or ultrasound frequency band range; 2) estimating a plurality of cascaded pre-filter time-domain responses used for carrying out the filtration treatment on the source signals on the basis of the iterative least square rule by combining the source signals and the focusing signals; and 3) re-sending the pre-filtered source signals by the guide sound source, and carrying out the operations of receiving,time-reversal and re-sending by the time-reversal array according to the conventional time-reversal process, so as to acquire the optimal focusing signal waveform at the location of the sound source.The invention can achieve the inverse-filtering and focusing effects within the time domains and recover the waveform of the source signals within the focusing region; the invention allows the randomdistribution of array elements and the difference in the frequency response among the array elements; and the invention has high spatial resolution.
Owner:INST OF ACOUSTICS CHINESE ACAD OF SCI

Single-frame infrared image based real-time detection method of point target

InactiveCN102346910AEasy to realize real-time detectionEasy to process in real timeImage analysisPoint targetInfrared image
The invention relates to a single-frame infrared image based real-time detection method of a point target, which handles each pixel through the steps that: (1) whether a pixel is the maximum point in an adjacent area or not is judged by comparing the gray between the pixel and other pixels in the 3*3 adjacent area; (2) the average gray value of a 3*3 adjacent area which takes the pixel as the central pixel is calculated; the proportion of the difference between the gray value of the central pixel and the average gray value, in the average gray value filter of the sum of the differences between the all pixels with the gray values being more than the average gray value and the average gray value, is calculated, the determination result of the point is set to be 1, and otherwise, the determination result of the point is set to be 0; (3) the proportion of the pixel in four directions is respectively calculated; if the proportion in each direction is more than a set edge detection proportion threshold, the determination result of the point is set to be 1, and otherwise, the determination result of the point is set to be 0; and (4) the determination results of Step (2) and Step (3) are summated as the value of the point in a final binarization value.
Owner:NAT SPACE SCI CENT CAS

Non-adaptive airborne non-side-looking radar short-range clutter suppression method

InactiveCN103744067ACan not meet the requirements of real-time processingMeet the requirements of real-time processingWave based measurement systemsComputation complexityRadar
The invention discloses a non-adaptive airborne non-side-looking radar short-range clutter suppression method. A non-adaptive short-range clutter suppression method formed by space-time filtering and space-time matching is used for suppressing airborne radar short-range clutter. The method comprises the steps of firstly arranging received signals of all channels of radar into a column vector, then performing space-time filtering to the received signals to suppress clutter energy, and finally performing space-time two-dimensional matching to realize the detection of a target. The non-adaptive airborne non-side-looking radar short-range clutter suppression method overcomes the defects that a great number of training samples which satisfy independent and identical distribution conditions are needed when the traditional adaptive clutter suppression method is applied to airborne radar, the calculation amount is great and the performance during short-range clutter suppression is seriously decreased. Compared with the traditional adaptive clutter suppression method, the method provided by the invention has the advantages that since the method is a non-adaptive method, the method is not influenced by non-uniform samples, the calculation complexity is low, the clutter suppression can be conveniently and quickly realized and the detection of the target is more greatly facilitated.
Owner:XIDIAN UNIV

Method for tracking depth of sound source autonomously in real time at deep sea under lower signal-to-noise ratio condition

The invention relates to a method for tracking the depth of a sound source autonomously in real time at deep sea under a lower signal-to-noise ratio condition. According to the method of the invention, piecewise linear approximation processing is performed on a sound velocity profile, so that the direction of arrival information of signals on a vertical array is obtained; the information is utilized to obtain the autocorrelation function of the signals, and the autocorrelation function of the signals contains sound source depth information; a plurality of equations with low computational quantities are adopted to obtain sound source depths corresponding to each time delay coordinate of the autocorrelation function; the autocorrelation function is transformed into a function which adopts ahypothetical sound source depth as an independent variable, and the function is called a depth correlation function; and a smoothing filter is applied to the time sequence of the depth correlation function so as to weaken background noises, extract the correlation peaks of the signals and track a sound source depth. Compared with the calculation amount of a traditional ray model-based sound sourcedepth estimation method, the calculation amount of the method of the invention is greatly reduced; and time accumulation gain is obtained with a small calculation amount and low storage cost, and therobustness of the method of the present invention under the low signal to noise ratio condition is improved.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

Multi-input and multi-output fast estimation method for radar receiving and transmitting angles under color-noise environment

InactiveCN103217671AImprove estimation performanceSuppresses the effect of Gaussian color noiseWave based measurement systemsMulti inputComputation complexity
The invention provides a multi-input and multi-output fast estimation method for radar receiving and transmitting angles under color-noise environment. The multi-input and multi-output fast estimation method comprises the following steps of: (1) carrying out matching and filtering on echo signals of all receiving array elements acquired by an A/D sampling module and obtaining received data of a virtual array; (2) carrying out rearrangement on the received data of the virtual array; (3) respectively carrying out subarray division on the received data and a rearranged matrix and meeting the characteristic of constant rotation of a transmitting end and a receiving end; (4) constructing two four-order cumulant matrix pairs; (5) obtaining signal subspaces including the characteristic of constant rotation in transmitting and receiving respectively by characteristic values; (6) estimating the receiving and transmitting angles of a target by utilizing an ESPRIT algorithm; and (7) realizing correct pairing of the receiving and transmitting angles by utilizing a maximum likelihood estimation method. The multi-input and multi-output fast estimation method provided by the invention has the advantages that the influence of Gaussian color noise can be effective inhibited, no special requirement exists for the quantity of transmitted/received array elements, the estimation accuracy is high, and the computation complexity is low, so that the multi-input and multi-output fast estimation method can be used for positioning targets on sea or at low altitude in tracking and guidance.
Owner:HARBIN ENG UNIV

Defect detection system

Scattered radiation from a sample surface is collected by means of a collector that collects radiation substantially symmetrically about a line normal to the surface. The collected radiation is directed to channels at different azimuthal angles so- that information related to relative azimuthal positions of the collected scattered radiation about the line is preserved. The collected radiation is converted into respective signals representative of radiation scattered at different azimuthal angles about the line. The presence and / or characteristics of anomalies are determined from the signals. Alternatively, the radiation collected by the collector may be filtered by means of a spatial filter having an annular gap of an angle related to the angular separation of expected pattern scattering. Signals obtained from the narrow and wide collection channels may be compared to distinguish between micro-scratches and particles. Forward scattered radiation may be collected from other radiation and compared to distinguish between micro-scratches and particles. Intensity of scattering is measured when the surface is illuminated sequentially by S- and P-polarized radiation and compared to distinguish between micro-scratches and particles. Representative films may be measured using profilometers or scanning probe microscopes to determine their roughness and by the above-described instruments to determine haze in order to build a database. Surface roughness of unknown films may then be determined by measuring haze values and from the database.
Owner:VAEZ IRAVANI MEHDI +4
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