1530 results about "Array element" patented technology

The invention relates to the technical field of defect detection, and discloses a flange forging defect detection method and system. The method comprises the following steps: performing three-dimensional scanning and material acoustic characteristic measurement on a to-be-detected wind power flange to obtain layer partition sound isolation path data; generating an array element excitation control file of the double-array phased array ultrasonic detection system; applying the array element excitation control file to a double-array phased array ultrasonic detection system, and performing micro defect feature enhancement on a received echo signal to obtain a feature-enhanced signal data set; performing ultrasonic emission and data acquisition on the wind power flange to obtain a global detection data set; and inputting the global detection data set into the two-stage defect detection model for defect feature extraction and classification evaluation, and generating a defect detection evaluation report. According to the method, the detection rate and the classification accuracy of the micro forging defects are improved.

The invention discloses a composite board ultrasonic defect detection method which comprises the following steps: S1, fixing a carbon fiber circumferential winding composite pressure container on a bracket, and establishing a coordinate system with the axis of the container as a z axis; s2, a 40 MHz dry coupling phased array ultrasonic probe is attached to the scanning starting point, and the contact angle of the probe is recorded; s3, moving the probe along the spiral track of the outer surface of the container at the speed of 20mm / s, and collecting A-scanning echo signals of all array elements; s4, performing pulse compression and time domain deconvolution processing on the acquired signal to obtain a time domain echo sequence; s5, delay time is calculated according to the shell curvature, the array element signals are compensated, and focusing B-scanning data are generated; s6, splicing the B-scanning data at the step length of 0.5 mm * 0.5 mm, and reconstructing C-scanning data corresponding to the space coordinates; and S7, inputting the C-scanning data into the trained Transform network, and outputting defect types, sizes and three-dimensional coordinates. The method realizes high-frequency ultrasonic composite board defect accurate detection, remarkably improves the microcrack recognition rate, and is widely applied to safety evaluation scenes of high-pressure hydrogen storage tanks and pressure vessels.

The present invention relates to the field of array antenna synthesis, and in particular to a sparse planar array synthesis method. In the present invention, in order to balance the proportion of a development and exploration process, a nonlinear function is used to reconstruct an arithmetic optimization accelerator in an arithmetic optimization algorithm; the top three optimal individuals are used to replace the current optimal individual to perform exploration and development and an elite mutation strategy is introduced, so as to enhance the capability of the algorithm to escape a local optimum, and improve the convergence precision of the algorithm; and an adaptive matrix mapping rule is provided, the current array element distribution is determined, and if the current array element distribution does not meet the minimum array element spacing constraint, the current array element distribution is adjusted by means of an adjustment strategy, thereby guaranteeing the degree of freedom of array elements while avoiding an unfeasible solution.

Provided in the present disclosure are a terminal and a sending device in a communication system. The sending device includes: a receiving unit, which is configured to receive position information of a terminal, and a control unit, which is configured to determine a first codeword in a first codebook and offset information according to the position information. The first codeword indicates initial phases of at least some array elements in a reconfigurable intelligent surface (RIS). The offset information indicates an offset relative to the at least one of the at least some array elements, the initial phases, and a reference position of the RIS.

The invention relates to the technical field of TDOA (time difference of arrival) positioning, and provides an ultrasonic three-dimensional positioning method based on beam enhancement and TDOA, which comprises the following steps: extracting initial space parameters based on beam scanning of an array receiving signal, carrying out iterative optimization on beam weight to adjust a direct wave component and suppress reflection interference, constructing a closed-loop optimization mechanism, and carrying out beam enhancement and TDOA positioning. Calculating an enhanced signal and an array element reliability measurement index through frequency domain segmentation and energy normalization; forming an optimization array based on the array element reliability measurement index, extracting a time delay parameter from the optimization array, constructing a distance measurement equation set, and calculating an initial estimation value of a target position by adopting a weighted optimization algorithm; and constructing a residual error model, constructing an optimized weight matrix by combining an array element reliability measurement index and a signal quality index, iteratively calculating a target coordinate until a convergence condition is met, and outputting a final three-dimensional coordinate. According to the method, the comprehensive performance of ultrasonic three-dimensional positioning in the aspects of anti-interference performance, stability and positioning precision in a complex environment is improved, and error source control is realized.

The invention relates to a Gaussian Newton method-based amplitude-phase error and direction-of-arrival joint estimation method, which comprises the following steps of: constructing a likelihood function about array element amplitude error, array element phase error and direction-of-arrival according to an array observation model, and calculating a cost function according to the likelihood function, converting a parameter estimation problem of the likelihood function into a parameter optimization problem to obtain a target function; calculating an initial value of a direction of arrival in the target function by adopting a MUSIC algorithm, and setting an initial value of an array element amplitude error and an initial value of an array element phase error; and according to the initial value of the direction of arrival, the initial value of the array element amplitude error and the initial value of the array element phase error, jointly estimating the array element amplitude error, the array element phase error and the direction of arrival by adopting a Gauss-Newton method to obtain an estimated value of the array element amplitude error, an estimated value of the array element phase error and an estimated value of the direction of arrival. According to the method, the influence of the array amplitude-phase error on the DOA estimation precision is reduced, and the DOA estimation performance is improved.

The invention discloses a rubber-lined pipeline defect detection method and system, and the method comprises the steps: arranging an ultrasonic probe array, obtaining large-area scanning information of a rubber-lined pipeline, collecting an ultrasonic signal, an echo signal and a resonance signal, generating a resonance signal curve, and reflecting a mapping image of the interior of the rubber-lined pipeline. And calculating a half-power bandwidth and a damping characteristic parameter, generating a corresponding characteristic vector through the identification model, identifying and positioning defects in the rubber-lined pipeline, evaluating the severity of the defects, and outputting an identification result. Through the structural design of arranging a plurality of array elements of the array probe, the coverage range is increased, ultrasonic wave emission and receiving are carried out on the rubber-lined pipeline from different angles and positions, the probability of discovering small-area debonding is improved, in addition, the machine learning technology is combined, an intelligent recognition model is trained, rich features are provided, and the detection accuracy is improved. The capability of identifying different types of defects is enhanced, the sensitivity to different types of defects is improved, and the risk of missing detection of small-area debonding is reduced.

The invention discloses a ring piece ultrasonic detection noise reduction and identification method and system and a computer storage medium. The method comprises the steps that a matched ultrasonic phased array probe is selected according to the shape and size of the cross section of a workpiece, and technological parameters are set and comprise at least one of the probe frequency, the number of array elements, the water layer height and the focusing depth; according to the selected ultrasonic phased array probe and process parameters, ring piece water immersion ultrasonic phased array detection is carried out, full-coverage scanning is carried out in a weld joint area, and the scanning position of the probe is recorded in real time through an encoder; in the scanning process, an ultrasonic image scanned by the phased array probe is collected in real time, and the ultrasonic image is transmitted to a pre-trained adaptive noise reduction YOLOv5 target detection model for defect recognition; and the rotating angle position of the ring piece is recorded in real time through an encoder, and when the target detection model finds defects, the defect position is recorded, and alarm information is generated. The method is suitable for ring piece ultrasonic detection noise reduction and recognition, the defect recognition accuracy can be improved, and the manual labor intensity is reduced.

A multi-antenna array-based improved GNSS anti-jamming method using an optimal weight coefficient, comprising the following steps: constructing a signal model for collecting observation signals x by a GNSS antenna array consisting of N array elements; on the basis of the signal model, acquiring a covariance matrix of signals received by the array; performing eigenvalue decomposition on the covariance matrix of the signals received by the array to obtain a matrix composed of eigenvectors; respectively constructing a jamming subspace and a signal-plus-noise subspace; on the basis of a linearly constrained minimum variance beamforming algorithm, designing a subspace constraint-based improved algorithm using an optimal weight coefficient; solving for the optimal weight coefficient on the basis of the linearly constrained minimum variance beamforming algorithm; and using the optimal weight coefficient to weigh the received signals to realize GNSS jamming suppression. According to the improved algorithm, prior information of direction angles of signals is not required, gains of real signals are protected while jamming is suppressed, and the problem of potential safety hazards caused by low-cost jammers is effectively alleviated.

The invention provides a high-imaging-resolution method for identifying a lead sealing defect part of a cable, and relates to the field of nondestructive testing. Comprising the steps that a linear array probe array is utilized, a plurality of array elements emit ultrasonic waves to a to-be-detected defect part at the same time, and a received echo signal reflects the waveform shape and the waveform phase of the defect. A two-dimensional image is preprocessed through a synthetic aperture focusing technology, a combined image is reprocessed through a phase coherence technology, the quality and accuracy of the image are further improved, and a high-resolution three-dimensional image is constructed in combination with an imaging synthetic aperture focusing technology. The ultrasonic phased array technology, the SAFT technology, the phase coherence technology and the synthetic aperture focusing technology are combined, the imaging resolution is effectively improved, the method has remarkable advantages especially when defect parts in complex structures such as cable lead seals are recognized, the imaging quality is optimized, a two-dimensional image is converted into a high-resolution three-dimensional image, and finally an accurate defect recognition result is obtained.

The invention discloses a projection dimensionality reduction rapid calculation method and system for a large-scale spherical column phased array scanning beam dynamic activation subarray plane, and belongs to the field of phased array measurement and control performance modeling, and the method comprises the steps: S1, setting parameters of a scheduling problem model; s2, acquiring orbit data of the aircraft, obtaining a visible time window set and calculating a visible arc section; s3, establishing a phased array resource set, and searching for an activated array element; and S4, establishing a large-scale phased-array antenna multi-beam scheduling objective function, and obtaining a final calculation result. According to the invention, the multi-beam measurement and control performance can be improved.

The invention provides an acoustic array adaptive calibration correction system applied to an underwater moving target, which relates to the technical field of marine equipment and comprises a multi-source excitation and environment perception module, an intelligent array perception and diagnosis module, an adaptive position inversion and uncertainty quantification module and a closed-loop calibration execution and self-learning optimization module. The multi-source excitation and environment perception module is responsible for providing reference signals required by calibration and establishing a correlation model of environment and formation distortion, and the intelligent array perception and diagnosis module realizes multi-modal data acquisition, array element health state monitoring and formation geometry self-perception. The adaptive position inversion and uncertainty quantization module completes signal processing, position estimation and error quantization propagation, and the closed-loop calibration execution and self-learning optimization module executes a compensation strategy, verifies a calibration effect and continuously optimizes system performance through online learning; the system solves the problem that a traditional method cannot process environment time varying, multi-sensor conflicts and uncertainty quantization.

The invention provides a design optimization method and device for an intracardiac ultrasonic transducer array, a medium and a program product, and relates to the technical field of ultrasonic imaging equipment. The method comprises the following steps: acquiring a marshalling scheme and independent array elements of an ultrasonic transducer array, and marshalling the independent array elements based on the marshalling scheme to form at least two independent equivalent sub-apertures; establishing a spherical coordinate system by taking the geometric center of the ultrasonic transducer array as an original point, determining a pre-deflection direction and an imaging focus of the pre-deflection focus representation array based on the spherical coordinate system, and calculating static time delay; calculating the geometric center coordinate of each equivalent sub-aperture and the flight time of the imaging focus to obtain the dynamic time delay of each equivalent sub-aperture; and obtaining a space sound field based on the static time delay, the dynamic time delay and other parameters. Under the limitation of a limited space, the imaging performance of the ultrasonic transducer array is maintained while array element connection and circuit design are optimized, so that high-quality imaging quality is obtained.

The invention relates to a nonlinear ultrasonic guided wave phased array imaging method based on mixed array elements and time reversal. The method comprises the following steps: exciting a fundamental wave and receiving a second harmonic wave at piezoelectric array elements of the fundamental wave and the second harmonic wave of an ultrasonic guided wave by using a center frequency respectively; full-matrix data of ultrasonic guided wave signals in the detected workpiece are obtained in a one-transmitting and one-receiving mode; a fundamental wave signal is suppressed and a second harmonic signal is enhanced by adopting a pulse inversion mode; for the full-matrix data after pulse inversion, utilizing continuous wavelet transform filtering to extract a second harmonic signal; respectively calculating the distance from the discretized imaging area to the excitation array element and the distance from the discretized imaging area to the receiving array element; and for each discrete pixel point, according to an excitation signal of a distance forward propagation fundamental wave and a received second harmonic signal back propagation, a pixel value is calculated by using a time domain topology energy equation, and local acoustic nonlinear imaging of the plate-shaped structure is realized.

The invention discloses a sparse cloth double-array element multi-frequency ambiguity resolution interference angle measurement method and system, relates to the technical field of radar measurement, realizes design of a multi-frequency signal frequency selection criterion, and further realizes non-ambiguity and high-precision angle measurement of all angles in an angle range required by engineering. According to the technical scheme, a physical baseline length and a reference frequency are set according to a layout space; deriving a plurality of signal carrier frequency design criteria according to the Chinese remainder theorem; calculating the carrier phase difference of the double-array-element receiving signals under different signal carrier frequencies; and reconstructing the congruence equation set, and solving the congruence equation set to solve ambiguity so as to obtain a target angle estimation value.

The invention discloses a weight-constrained array antenna shaped beam gain optimization method and device, and the method comprises the steps: setting an array structure and target shaped beam parameters according to a set target; according to the relational expression of the weight and the directivity coefficient, constructing a shaped beam maximization directivity coefficient weight optimization model; obtaining an initial array weight according to the main lobe width of the target beam; solving and optimizing variables in the optimization model through an alternating direction multiplier method to obtain an optimization result, calculating an original error of the variables according to the result, and obtaining a maximum value of the original error through calculation; comparing the original error with a set error threshold, if the original error is smaller than the set error threshold, stopping iteration, and outputting a final array element weight; and if the original error is not smaller than the set error threshold, iteratively calculating the original error until a set iteration frequency is reached, and outputting a final array element weight. According to the invention, the main lobe gain can be improved and the amplitude dynamic range ratio can be reduced while the beam shape is satisfied.

The invention relates to a thin cloth rectangular plane broadband array antenna synthesis method, and belongs to the technical field of array antenna optimization. The method comprises the following steps: firstly, establishing a mathematical model of a rectangular plane broadband array antenna, initializing parameters of the broadband array antenna, and performing sparse processing on a full array by using a Kaiser weighting function; secondly, initializing a sparse array position population by adopting Tent chaotic mapping, calculating an array element to generate a population fitness function value, and recording an optimal individual; thirdly, adopting an improved grey wolf optimization algorithm to carry out sparse optimization on the sparse array, calculating an updated array element fitness value, extracting an optimal fitness value, recording a corresponding array element position, and outputting an optimal array element position arraying scheme; and finally, obtaining a frequency invariance directional diagram with a smaller side lobe based on the SRV constraint of infinite norm. According to the invention, the number of antenna array elements can be effectively reduced, the frequency-invariant wave beam of the minimum side lobe is realized, and the cost of an antenna system is reduced while the performance of the broadband array antenna is ensured.

The invention relates to the technical field of signal analysis, in particular to a GNSS (Global Navigation Satellite System) detection method and system based on machine learning, and the method comprises the steps: receiving a navigation radio-frequency signal containing reality and deception, and carrying out the down-conversion of an RF (Radio Frequency) front end to obtain intermediate-frequency data; gNSS signal capture is completed by searching correlation peaks in frequency and code phases based on intermediate frequency data; in the capturing stage, a motion state, a correlation peak number, a noise value, capturing parameters and peak + / -1 chip sampling features are extracted and input into a machine learning classification model to judge whether cheating exists or not; if so, separating the deception signal from the real signal, and respectively sending the deception signal and the real signal into independent tracking channels; measuring an array element carrier relative phase by an array antenna, establishing a phase center model, and correcting to obtain an effective phase center and a differential baseline; according to the method, a deception azimuth angle and a pitch angle are obtained, a beam weight is calculated, a deception direction is subjected to null setting, a real direction is subjected to main lobe protection, and a weight value is fed back in real time to improve a signal carrier-to-noise ratio and locking stability. According to the invention, the problem that the existing commercial GNSS signal is low in power and easy to be interfered by deception is solved.

The invention discloses a large-scale phased array multi-channel partition beam control method and device based on an FPGA and a storage medium. The method comprises the steps that a control instruction of an antenna control unit is acquired; analyzing the control instruction which is verified to be correct, judging an instruction type according to an analysis result, when the instruction type is a beam switching instruction, determining a beam control parameter in the instruction, and calculating a base code of the phased-array antenna according to the beam control parameter; the array elements of the phased-array antenna are divided into a plurality of areas, according to the base codes and the position coordinates of the array elements, the wave control codes of the array elements are calculated in parallel by adopting a multi-channel partitioning method, and the wave control codes are normalized and then written into a beam forming chip in parallel; and after the operation is completed, a corresponding response instruction is sent to the antenna control unit. The method has the advantages of being high in beam switching speed, small in resource consumption and good in universality, an array can form a sparse array in the mode of sending a control instruction, and therefore side lobes are restrained, and power consumption is reduced.

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

The invention relates to an underwater acoustic image reconstruction method based on angle error compensation, which comprises the following steps of: (1) calculating space coordinate information and a two-way slant range course of a transmitting array element and a receiving array element for each subsystem consisting of the receiving array element and the transmitting array element; (2) calculating a two-way slant range course after phase center approximation; (3) calculating a system function of a distance-Doppler domain; (4) calculating a Doppler phase error; (5) dividing the data into # imgabs0 data blocks which are not overlapped with one another, and compensating micro-range migration errors caused by range errors; (6) obtaining a signal after distance delay error compensation; (7) performing differential range migration correction processing, range pulse compression, secondary range pulse compression and consistent range migration correction processing; (8) carrying out azimuth focusing processing, residual phase error compensation operation and azimuth walking correction processing; and (9) performing coherent fusion processing and inverse Fourier transform to obtain a final high-resolution image. According to the method, the image can be quickly reconstructed, and the real-time processing requirement can be met.

The invention belongs to the technical field of array antenna synthesis, and particularly relates to a thin cloth rectangular planar array antenna synthesis method, a program, equipment and a storage medium. According to the method, a thin cloth rectangular planar array antenna comprehensive method is converted into an optimization problem of an array element position in a quadrant, an improved sparrow algorithm is adopted, Kent mapping population initialization is introduced, and diversity of an initialized population is enhanced; the idea of a sine and cosine algorithm is fused in a position updating strategy of a discoverer, and a nonlinear sine learning factor is introduced to enhance all search capabilities; and finally, a crisscross strategy is introduced into a sparrow algorithm, and the optimization precision is improved by improving a search mode of a supervisor.

The invention discloses a broadband digital beam forming method based on a Farrow filter, and the method comprises the following steps: carrying out the DDC down-conversion and phase shift processing of a signal after the analog-to-digital conversion of a broadband signal is completed through an ADC; calculating the delay inequality of each array element signal relative to a reference array element, and decomposing the delay inequality into an integer sampling period and a fractional delay component; a fourth-order Lagrange type Farrow filter oriented to FPGA / DSP optimization is adopted to carry out fractional time delay compensation, and coefficients of the Farrow filter are dynamically adjusted through a polynomial expansion formula; and finally, performing complex weighted synthesis on each channel filtering signal to generate a directional wave beam. According to the method, high-precision fractional delay adjustment is achieved, the Farrow filter is adopted, the tedious process of recalculating coefficients can be omitted, only the P value is changed, and high-precision beam direction control can be achieved under the condition of low calculation amount.

The invention belongs to the technical field of underwater target radiation noise measurement, and particularly relates to a sparse combination array measurement system and method for underwater target radiation noise measurement, a program and a storage medium. A sparse combined array formed by a sound pressure spiral double-cone volume array with a sparse structure and a sound pressure vector nested vertical linear array is designed, a combined array frequency-division testing scheme of a high-frequency volume array and a low-frequency vertical linear array is adopted, a combined measurement method of a sound pressure hydrophone and a vector hydrophone is utilized, a measurement frequency band is extended, and the measurement precision is improved. And effective measurement of the full-band radiation noise of the underwater target is realized. Through a sparse array arrangement structure and an improved constant-beam-width beam forming method, a two-dimensional steady constant-beam-width beam is obtained while the number of array elements is reduced and the array complexity is reduced, and an appropriate main lobe width and a lower side lobe level can be adjusted according to a measured target and a measurement distance. According to the method, the array element redundancy of the measurement array is reduced, and the method can be flexibly applied to various application scenes of underwater radiation noise measurement.

The invention belongs to the technical field of underwater sound information processing, and relates to a position configuration method of an array calibration sound source of a seabed sound array in a deep sea environment, which comprises the following steps of: constructing a time delay observed quantity model between a calibration sound source and an array element based on a ray sound propagation theory; deriving a relation between an unbiased estimation error lower bound of an array element position and a calibration sound source position, constructing an array calibration performance constraint condition and a calibration source number sparse constraint condition to realize automatic selection of a calibration sound source number, and adopting a positive semidefinite programming technology to solve an optimization configuration problem; compared with a traditional calibration sound source position configuration method, the method adopts the ray acoustic propagation model to model and calibrate the time delay observed quantity between the sound source and the array element, is more in line with the characteristics of the marine environment, and can realize effective compensation of the sound propagation effect.

The invention discloses a passive synthetic aperture method and device based on R-L deconvolution beam domain processing, a medium and equipment, and the method comprises the steps: constructing a formation distortion model of a towed array under disturbance, and processing a discretized formation distortion model through a Kalman filter, so as to obtain the absolute coordinates of each array element; determining a receiving signal time domain solution of each array element based on the sound pressure expression and the absolute coordinates; based on an ETAM algorithm, obtaining beam output of overlapped sub-arrays in adjacent time samples, and performing R-L iteration on the beam output to obtain a phase compensation factor; and performing phase compensation based on the wave beam output of the phase compensation factor to obtain each phase correction wave beam and the wave beam output of the synthetic aperture. The passive synthetic aperture algorithm and the R-L deconvolution wave beam forming technology are effectively combined, so that the accuracy of the phase compensation factor after formation distortion is generated is improved to the maximum extent, and the accuracy of the phase correction wave beam is improved. Therefore, the algorithm provided by the invention still provides high-precision target positioning under the condition that the ETAM algorithm fails.

The invention discloses an imaging method, system and device for correcting range migration based on frequency domain phase multiplication, and the method comprises the following steps: carrying out the range pulse compression of echo data of each receiving array element in a range frequency domain; performing data preprocessing according to a phase center approximation method to obtain equivalent transmit-receive combined synthetic aperture sonar data; deriving a secondary distance compression item at the reference distance in the two-dimensional frequency domain, and performing secondary distance compression processing; deriving a space-variant migration phase term of range migration correction corresponding to each target with different distances; carrying out filtering processing on the two-dimensional frequency domain sonar data; a filtered result is converted to a range-direction time domain and an azimuth-direction Doppler domain, data of targets at corresponding distances are extracted, and the data extracted each time are combined in sequence; and for the data after range migration correction, azimuth pulse compression is carried out in a range time domain and an azimuth Doppler domain, and the data is converted to a two-dimensional time domain to obtain a sonar image.