26 results about "Discrete spectrum" patented technology

The invention relates to the technical field of motor diagnosis, and discloses a motor eccentricity fault diagnosis method and system based on current harmonic analysis, and the method comprises the steps: carrying out the power frequency component extraction of a three-phase stator current signal, obtaining a residual current signal, carrying out the complex analysis envelope transformation of the residual current signal, and obtaining an envelope analysis signal; performing synchronous interpolation resampling on the envelope analysis signal to obtain a complex envelope signal; performing frequency spectrum estimation on the complex envelope signal to obtain a discrete frequency spectrum of a module value sequence; performing equalization processing on the order spectral line amplitude in the discrete spectrum to obtain a whitened spectrum, and performing inverse transformation on the whitened spectrum to reconstruct an angular domain amplitude signal of the target motor; performing cyclostationary analysis on the angular domain amplitude signal to obtain a third-order cyclic cumulant of the angular domain amplitude signal at a specific cyclic frequency; according to the third-order cycle cumulant, the type and severity level of the eccentric fault are judged; the accuracy of motor eccentricity fault diagnosis can be improved.

The invention discloses a spectrum super-resolution method and system based on an FP cavity and deep learning, and the method comprises the steps: S1, carrying out the initialization of spectrum collection, and selecting light with a specific wavelength after the light is acted with a target detection object; s2, performing photoelectric conversion and digitization to generate low-resolution original discrete spectrum data of corresponding wavelengths; s3, continuous spectrum scanning is carried out, and original discrete spectrum data collection of the whole target wave band is completed; and S4, performing super-resolution spectrum reconstruction, and judging whether cyclic reconstruction is performed or not based on a reconstruction data quality evaluation result until the quality is qualified. According to the method, an accurate mapping model from a low-resolution spectrum to a high-resolution spectrum is established through a pre-trained deep neural network, and an original spectrum which is collected by an FP cavity and is limited by the theoretical limit optical resolution of the FP cavity can be reconstructed into a super-resolution spectrum of which the resolution remarkably exceeds the theoretical limit. The problem that the resolution of an FP cavity in a long-wave region is sharply reduced is effectively solved, and the full-wave-band uniform high resolution is realized.

The application provides a method and device for evaluating the harmonic interference degree of a converter transformer by using a vibration signal. The method comprises the following steps: collecting multiple vibration signals collected by multiple vibration sensors as vibration samples; obtaining the frequency spectrum of each vibration sample; constructing a discrete frequency spectrum sequence of the vibration sample by using the amplitude of a preset reference frequency and its multiple frequencies in the frequency spectrum of the vibration sample; identifying the effective local peak value of the discrete frequency spectrum sequence of each vibration sample; calculating the energy concentration degree feature and the energy distribution entropy feature of the vibration sample based on the effective local peak value; and finally evaluating the harmonic interference degree of the converter transformer at the current moment according to the energy concentration degree feature and the energy distribution entropy feature of each vibration sample. The scheme evaluates the harmonic interference degree of the converter transformer by using the vibration signal, thereby preventing the converter transformer from malfunctioning due to excessive harmonic interference.

The invention belongs to the technical field of distributed optical fiber sensing, and relates to an anti-distortion distributed optical fiber sensing method and system based on array phase spectrum demodulation, an ultra-weak reflection optical fiber Bragg grating array is used as a sensing optical fiber, a series of reflection peaks with the signal-to-noise ratio higher than that of RBS are generated, a reflection peak sequence is formed, and the beat frequency signal spectrum amplitude is increased. A discrete beat frequency signal with frequency domain distortion output by an OFDR sensing system is converted to a frequency domain through Fourier transform of a symmetric window function to obtain a corresponding discrete frequency spectrum, and characteristic parameters such as amplitude and phase of a reflection peak sequence in the frequency spectrum are tracked and extracted; and then frequency correction factors of the reflection peak sequence in all measurement periods are calculated by using an amplitude interpolation correction method to obtain a corrected accurate array phase spectrum, and phase difference and strain calculation are performed to realize multi-point quasi-distributed strain demodulation for suppressing frequency domain distortion such as Doppler frequency shift and the like. The frequency resolution limitation caused by the fence effect is broken, and the fidelity of the frequency domain distortion signal is recovered.

The invention discloses a method for determining structural stress range distribution and related equipment, which output stable and reliable structural stress range distribution by optimizing a frequency domain discrete and time domain reconstruction mode and combining a multi-round statistical optimization and fusion strategy. The method comprises the following steps: acquiring a stress power spectrum of a target structure, randomly dividing frequency intervals in a preset frequency band and distributing phases to obtain a discrete spectrum; reconstructing a time domain stress time calendar and carrying out rain flow counting, and generating multiple groups of dimensionless rain flow stress range probability density distributions; and after average fairing and moment keeping correction, candidate sub-distribution is generated by adopting a multi-fairing strategy, and final distribution is obtained by combining evaluation index weighted fusion. According to the method, the time calendar authenticity is improved through random discretization, distribution convergence is realized through multi-time statistical fusion, and smoothness and statistical characteristics are taken into account through moment maintenance and multi-strategy fusion. Only stress power spectrum input is needed, the method is suitable for complex scenes such as broadband and multi-peak spectrum, the method can be embedded into an existing system for automatic operation, analysis cost is reduced, and fatigue evaluation precision is improved.

The application relates to the technical field of motor diagnosis, and discloses a motor eccentric fault diagnosis method and system based on current harmonic analysis. The method comprises the following steps: extracting a power frequency component of a three-phase stator current signal to obtain a residual current signal, and performing complex analytic envelope transformation on the residual current signal to obtain an envelope analytic signal; performing synchronous interpolation resampling on the envelope analytic signal to obtain a complex envelope signal; performing spectrum estimation on the complex envelope signal to obtain a discrete spectrum of a modulus sequence; performing equalization processing on the order spectrum line amplitude in the discrete spectrum to obtain a whitened spectrum, and inversely transforming and reconstructing the whitened spectrum into an angular domain amplitude signal of a target motor; performing cyclic stationary analysis on the angular domain amplitude signal to obtain a third-order cyclic cumulative quantity of the angular domain amplitude signal at a specific cycle frequency; and determining the type and severity level of the eccentric fault according to the third-order cyclic cumulative quantity. The application can improve the accuracy of motor eccentric fault diagnosis.

The invention relates to a digital transmitter (10) for providing a high-frequency analog signal, the transmitter comprising: conversion means (3) for receiving a digitally modulated baseband signal (12) and providing a discrete spectrum of the digitally modulated baseband signal (12) in polar coordinates or in oblique coordinates; and a synthesis means (90) for generating the high-frequency analog signal on the basis of the discrete spectrum provided in polar coordinates or in oblique coordinates, where the synthesis means (90) is a means for performing a continuous inverse Fourier transform. The invention also relates to a method for providing a high-frequency analog signal, comprising: receiving a digitally modulated baseband signal; and providing a discrete spectrum of the digitally modulated baseband signal in polar coordinates or in oblique coordinates; and generating the high-frequency analog signal based on the discrete spectrum provided in polar coordinates or in oblique coordinates by performing a continuous inverse Fourier transform.

The present application relates to the field of optical fiber sensing technology, and more particularly to a kind of FP-FBG fusion spectrum demodulation method based on discrete spectrum analysis, comprising: driving tunable laser quasi-continuous scanning FP-FBG sensor and obtaining discrete reflection spectrum sequence through photoelectric acquisition circuit, determining the index of FBG peak in the sequence and obtaining FBG center wavelength by using centroid method fitting, selecting target neighborhood with the index as center and replacing the neighborhood sequence value with the intensity mean of spectrum sequence to obtain processed FP spectrum sequence, performing autocorrelation transformation on the processed FP spectrum sequence to obtain autocorrelation sequence, and finding the peak-to-peak distance between main peak and adjacent peak in the autocorrelation sequence, and finally calculating the sensing demodulation result according to the calibration relationship.The present application can effectively remove the shielding of narrow-band FBG to FP spectrum period information, suppress random noise and significantly improve the demodulation accuracy of low-quality spectrum.

The invention discloses an infrared spectrum detection method, device and system for wearable equipment. The device can be implemented as an integrated circuit chip, a module or a chip-module combination. The device comprises a multi-discrete SWIR light source driving and interface unit, an InGaAs detection reading unit, a time division scanning control unit and a synchronous demodulation processing unit. The control unit sequentially drives the multiple discrete SWIR light sources to emit according to a preset time division scanning sequence, and modulates emitted light in each time slot; the InGaAs detector collects skin reflection or back scattering signals, the synchronous demodulation unit executes related demodulation or phase-locked demodulation, amplitude features of all discrete wavelengths are extracted, and discrete spectrum feature vectors are formed and output. The scheme is suitable for wearable equipment, and has the advantages of resisting ambient light interference, being capable of expanding multi-emission position or multi-distance measurement and facilitating chip and modular integration.

The application belongs to the field of deep learning and remote sensing image processing, and specifically discloses a hyperspectral few-shot classification network construction method and a hyperspectral feature classification method, which comprises the following steps: acquiring hyperspectral remote sensing images and sample label data thereof; performing cross-domain reconstruction and spectrum curve extraction, and filtering common information between categories through eigenvalue decomposition to obtain discrete spectrum curves; extracting physical invariance features and taking them as constraint rules to generate virtual samples; inputting the reconstructed hyperspectral data and spectrum self-supervised auxiliary information into a double-branch variational autoencoder network to perform multi-loss constraint of cross reconstruction, so that the hyperspectral data and the spectrum self-supervised auxiliary information of the same category show greater similarity in the latent space; and outputting final feature prediction results based on a multinomial logistic regression classifier to complete the construction of the hyperspectral few-shot classification network. The application can realize high-precision and high-robustness hyperspectral feature classification under the condition of sample scarcity.

This invention discloses a time-difference localization method for frequency-hopping radiation sources based on the maximum discrete spectral value, relating to the field of frequency-hopping radiation source localization technology. The method includes the following steps: constructing a model of the frequency-hopping signal received by the observation station based on the geometric positions of the observation station and the target radiation source; establishing an approximate expression for the frequency-hopping signal based on the discrete spectral characteristics of the signal; generating an objective function related only to the radiation source position using the target radiation source position information contained in the received signal; and achieving direct localization of the frequency-hopping radiation source through an exhaustive search algorithm. This method is advantageous for direct localization, provides accurate localization, and possesses strong versatility and scalability.

This application discloses a method and related equipment for determining the stress range distribution of a structure. By optimizing the frequency domain discretization and time domain reconstruction methods, combined with multi-round statistical optimization and fusion strategies, a stable and reliable structural stress range distribution is output. The method includes: acquiring the stress power spectrum of the target structure, randomly dividing frequency intervals within a preset frequency band and assigning phases to obtain a discrete spectrum; reconstructing the time domain stress history and counting rainflow to generate multiple sets of dimensionless rainflow stress range probability density distributions; after average smoothing and moment preservation correction, using a multi-smoothing strategy to generate candidate sub-distributions, and combining them with evaluation indicators for weighted fusion to obtain the final distribution. This application improves the realism of the time history through random discretization, achieves distribution convergence through multiple statistical fusions, and balances smoothness and statistical characteristics through moment preservation and multi-strategy fusion. Only the stress power spectrum is required as input, making it suitable for complex scenarios such as broadband and multi-peak spectra. It can be embedded into existing systems for automated operation, reducing analysis costs and improving fatigue assessment accuracy.

The invention provides an electric power system transient stability evaluation method and an electric power system running track prediction method based on a Koopman operator. The electric power system transient stability evaluation method comprises the steps of S1, collecting running track data of state variables of an electric power system; s2, raising the dimension of the collected state variable to a high-dimensional linear space by using an EDMD method, and approximating the effect of a Koopman operator by using a finite-dimensional linear matrix K; s3, positioning a discrete spectrum of a stable equilibrium point of the power system by using spectral decomposition of a Koopman operator, and finding the stable equilibrium point of the power system in an original state space by using characteristics of an eigenvalue of the Koopman operator and inverse mapping of a dictionary function; and S4, constructing a transient stability criterion of the power system based on the obtained stable equilibrium point and analysis of a linear system stability mechanism, collecting any working point after the power system is subjected to large disturbance, and judging whether the system is in transient stability or not by using the transient stability criterion.

The application provides an infrared wide-spectrum classification method and system for isomorphism objects with different materials, and belongs to the technical field of infrared photoelectric imaging and target classification and identification. The method comprises the following steps: normalizing a one-dimensional discrete spectrum signal to a 0-1 range; decomposing the normalized one-dimensional discrete spectrum signal into an intrinsic mode signal by EMD; obtaining an i*n-sized spectrum signal interpolation matrix by cubic spline interpolation of the intrinsic mode signal; performing point multiplication of the spectrum signal interpolation matrix and a full-spectrum weight matrix to obtain a spectrum feature matrix; and inputting the spectrum feature matrix into a spectrum classification model to obtain a spectrum category. The application can effectively extract real information in the spectrum while suppressing noise in the spectrum, and can guarantee the accuracy of the classification result by using a neural network under the condition of few samples.

The invention discloses an unmanned aerial vehicle communication spectrum sharing method, device and equipment based on a game theory, and belongs to the field. Comprising the following steps: acquiring position information and QoS requirement information of an unmanned aerial vehicle, a ground user and D2D equipment; performing joint optimization on the physical hovering position of the unmanned aerial vehicle and spectrum resource allocation by adopting a particle swarm algorithm and a discrete spectrum allocation algorithm based on a signal to interference and noise ratio threshold to obtain an optimal position of the unmanned aerial vehicle and an initial optimal spectrum allocation scheme; constructing a Stackelberg game model, solving by adopting a reverse induction method and a price threshold spectrum access algorithm, calculating a maximum spectrum unit price, and obtaining an optimal spectrum lease price and a final D2D device access strategy; and according to the final D2D device access strategy, controlling the corresponding D2D device to access a frequency band indicated by the final D2D device access strategy, and indicating the unmanned aerial vehicle to hover at the optimal position of the unmanned aerial vehicle to execute communication resource scheduling.

Systems and methods for massively parallel trimming of semiconductor devices include a thermal testing system configured for: receiving a first signal from a device under test, the first signal having an unknown first frequency; receiving a second signal from a local oscillator at a known second frequency; mixing the first signal and the second signal; filtering the mixed signal through a low-pass filter circuit; digitizing the filtered signal into a plurality of digital signal samples; windowing the plurality of digital signal samples within a frequency window; computing a discrete spectrum of the digital signal samples within the frequency window using a Fast Fourier Transform algorithm; fitting a plurality of consecutive frequency bins in the discrete spectrum to an interpolating function; evaluating the unknown first frequency based on the fitting; and electronically trimming the DUT according to the evaluated first frequency.

The application discloses a sine wave frequency estimation method based on a minimum amplitude difference strategy, which comprises the following steps: receiving a sine wave signal, performing fast Fourier transform on the received sine wave signal to obtain discrete spectral lines; finding the position and amplitude of the peak spectral line and adjacent spectral lines of the signal discrete spectrum; and interpolating two spectral lines at the middle position of the peak spectral line and adjacent spectral lines of the signal discrete spectral line; selecting the double spectral line with the minimum amplitude difference from the peak spectral line, the adjacent spectral line and the interpolated spectral line as a reference spectral line, and constructing a ratio equation according to the selected reference spectral line to estimate the frequency. The application selects the double spectral line with stronger anti-noise capability through the minimum amplitude difference strategy to perform frequency estimation, so that the estimation accuracy of different frequency signals is improved, and the frequency estimation accuracy and stability are good, and the calculation complexity is low.

The invention discloses a radar ranging method based on frequency domain phase correction, which comprises the following steps: synchronously sampling a transmitted wave signal and a reflected wave signal to respectively obtain discretized time domain signals xt (n) and xr (n), windowing to obtain time domain signal sequences yt (n) and yr (n), and respectively carrying out FFT (Fast Fourier Transform) operation to obtain time domain signal sequences yt (n) and yr (n); a high-precision synchronous analog-to-digital converter is adopted to sample the transmitted wave signal and the reflected wave signal after frequency reduction at the same time to obtain an original time domain discrete signal, FFT is executed after windowing to obtain discrete spectrum data of the signal, and a correction coefficient is obtained through a special phase correction algorithm for calculation; after the phases of the transmitted wave and the reflected wave are corrected, a high-precision transmitted wave phase and a high-precision reflected wave phase are obtained respectively, a high-precision distance value is obtained through the relation between the phase difference and the distance, and high-precision radar ranging is achieved.

The application discloses a kind of based on amplitude heterogeneity partial amplitude death implementation method.By constructing the Stuart-Landau coupled oscillation system model with the amplitude heterogeneity subject to uniform distribution, the conjugate average field coupling is introduced, combined with partial amplitude death steady-state analysis and its linear stability analysis, the continuous spectrum and discrete spectrum of coupled oscillator system are solved, the upper boundary of partial amplitude death boundary and the amplitude death proportion expression are determined.The influence of amplitude distribution parameters and coupling strength on partial amplitude death can be determined, and the partial amplitude death boundary line, death proportion and phase transition process can be identified.This method breaks through the limitations of traditional numerical simulation fitting, and the scheme is universal, which can meet the high-precision regulation and control requirements of complex coupled systems.It can provide reliable theoretical basis and technical support for the dynamic analysis, structure optimization and precise regulation and control of complex oscillation systems such as nonlinear systems, coupled oscillators, artificial neural networks and power systems.

The application belongs to the technical field of distributed optical fiber sensing, and relates to an anti-distortion distributed optical fiber sensing method and system based on array phase spectrum demodulation. A series of reflection peaks with a signal-to-noise ratio RBS higher than that of a reflection peak are generated by using a super-weak reflection fiber Bragg grating array as a sensing optical fiber, a reflection peak sequence is formed, and the spectral amplitude of a beat frequency signal is increased. The discrete beat frequency signal with frequency domain distortion output by an OFDR sensing system is converted to the frequency domain by Fourier transform with a symmetric window function to obtain the corresponding discrete frequency spectrum, the amplitude, phase and other characteristic parameters of the reflection peak sequence in the frequency spectrum are tracked and extracted, the frequency correction factor of the reflection peak sequence at all measurement periods is calculated by using an amplitude interpolation correction method, the corrected accurate array phase spectrum is obtained, and phase difference and strain calculation are performed, so that multi-point quasi-distributed strain demodulation for suppressing frequency domain distortions such as Doppler frequency shift is realized, the frequency resolution limitation caused by the fence effect is broken, and the fidelity of the frequency domain distortion signal is restored.

The invention relates to a frequency division multi-beam phase control receiver, and belongs to the technical field of wireless communication. The receiver comprises antenna channels and a power combiner, each antenna channel corresponds to a phased-array antenna unit, radio-frequency signals received by the antenna units are filtered, after out-of-band noise and interference components are filtered out, the radio-frequency signals are multiplied by time discrete signals corresponding to preset discrete frequency spectrums to be modulated to different frequency points, and the frequency spectrums are modulated to different frequency points. The amplitude and the phase of each frequency point correspond to the amplitude and the phase of the discrete spectrum; and the power combiner synthesizes the beam signals of different frequency points so as to obtain a frequency division multi-beam signal. According to the invention, a plurality of signals from different directions are moved to different frequencies, the spatial multiplexing and frequency domain multiplexing capabilities of the phased array are improved, the number of amplitude-phase channels in the multi-beam phased array is reduced, the complexity of a power division network is reduced, the cost is low, the capacity is high, and the like. The front-end receiver architecture can be used as a front-end receiver architecture in a multi-beam phased array system and an anti-interference navigation system.

The invention discloses a frequency hopping radiation source time difference positioning method based on a maximum discrete spectrum value, and relates to the technical field of frequency hopping radiation source positioning. The method comprises the following steps: constructing a frequency hopping signal receiving model of an observation station according to geometric positions of the observation station and a target radiation source; establishing an approximate expression of the frequency hopping signal according to discrete spectrum characteristics of the frequency hopping signal; using target radiation source position information contained in the received signal to generate a target function only related to the radiation source position; and the direct positioning of the frequency hopping radiation source is realized through an exhaustive search algorithm. According to the method, direct positioning is facilitated, positioning is accurate, and high universality and expandability are achieved.

The invention discloses a fusion magnet power supply impact power identification method based on data slicing, and belongs to the technical field of fusion power supply monitoring. The method comprises the following steps: obtaining magnet power supply time-power data, and carrying out slicing processing to obtain a power amplitude spectrum; carrying out continuity analysis based on array non-zero value distribution density, and dividing into a continuous spectrum, a weak discrete continuous spectrum and a discrete spectrum; analyzing corresponding intervals of the continuous spectrum and the discrete spectrum to obtain a short-time impact power amplitude range and a steady-state power interval of mixed long-time impact power; through array sorting accumulation and percentage processing, a data point dense distribution interval is extracted to realize accurate steady-state power identification; and time domain distribution of long-time impact power and short-time impact power is distinguished in combination with time axis continuity judgment. According to the method, accurate identification and amplitude and pulse width parameter extraction of three types of power are realized, and the configuration optimization and operation efficiency of the fusion power supply system is improved.

The application provides a mechanical rotating part acoustic emission fault diagnosis method based on bidirectional weighted cyclic stationarity, which comprises the following steps: collecting an acoustic emission signal to be diagnosed, obtaining a cyclic spectrum coherence function, and obtaining a baseline discrete spectrum coherence mapping and a diagnosis discrete spectrum coherence mapping; based on the baseline discrete spectrum coherence mapping and the diagnosis discrete spectrum coherence mapping, a spectrum frequency weight redistribution vector is obtained; based on the cyclic spectrum coherence function, a difference spectrum coherence matrix is obtained; and based on the spectrum frequency weight redistribution vector and the difference spectrum coherence matrix, a bidirectional reweighted difference spectrum coherence matrix is obtained. The application integrates healthy baseline data as prior information into a cyclic stationarity analysis framework, innovatively combines the difference and weighting ideas, deeply excavates the unique advantages and potential of the acoustic emission technology in the field of fault diagnosis, fully meets the needs of complex and variable industrial application scenarios, and has practical application value.

The invention discloses a flicker parameter estimation method and module based on windowing optimization linear frequency modulation Z transformation, and relates to the field of electric energy quality monitoring. The method comprises the steps that a voltage flicker signal in a power distribution network is acquired; performing envelope extraction on the voltage flicker signal by adopting an improved square detection algorithm to obtain a flicker envelope signal; a Kaiser-Nuttall mixed window function is applied to the flicker envelope signal, linear frequency modulation Z transformation analysis is carried out, and a discrete frequency spectrum is generated; and based on the discrete spectrum, correcting the frequency and amplitude of the flicker parameter by adopting a triplet spectrum interpolation algorithm to obtain a high-precision flicker parameter estimation result. According to the method, accurate extraction of a flicker envelope is realized by improving square detection and analytic modal decomposition, spectrum leakage is inhibited by combining a Kaiser-Nuttall mixed window with linear frequency modulation Z transformation, and finally, high-precision estimation of a module on a flicker amplitude value and a frequency parameter in an electric energy quality monitoring device is realized by combining a triplet spectrum interpolation algorithm.