13 results about "Harmonic coefficient" patented technology

The invention discloses a de-noising method and device for a wire vibration acceleration signal, electronic equipment and a storage medium, and belongs to the technical field of signal de-noising, and the method comprises the steps: collecting a vibration acceleration signal which is not de-noised, and then cyclically executing decomposition and reconstruction; in each round of iteration, determining a modal decomposition order range according to a current signal, and selecting an optimal order with the maximum weighted kurtosis; selecting an optimal penalty factor with the maximum harmonic coefficient from a preset penalty factor range; and decomposing and generating candidate modal components based on the two parameters, and screening effective components to reconstruct a new signal. And judging a convergence state by calculating an energy difference value between the current reconstructed signal and the last reconstructed signal: if the difference value is smaller than a threshold value, outputting a final de-noised signal, otherwise, taking the current reconstructed signal as the next input to continue iteration. Therefore, by implementing the method and the device, the problem that de-noising of the wire vibration acceleration signal is not accurate enough in the prior art can be solved.

The invention discloses a method for identifying a micro-vibration source of a reaction wheel, which comprises the following steps of: firstly, testing micro-vibration signals of the reaction wheel under a plurality of rotating speed working conditions, then carrying out noise reduction processing on the micro-vibration signals under each rotating speed working condition, converting the micro-vibration signals into frequency domain signals, and identifying the micro-vibration source of the reaction wheel on the basis of amplitude-frequency response under each rotating speed working condition. The method comprises the steps that firstly, a three-dimensional frequency spectrum waterfall plot with micro-vibration changing along with the rotating speed is formed, then, based on theoretical values and test values of modal frequency characteristics, a characteristic peak value is extracted, modal characteristics in the three-dimensional frequency spectrum waterfall plot are recognized and verified, and finally, a vibration source is positioned based on the characteristic peak value, the modal characteristics and rotor-bearing vibration frequency characteristics. According to the recognition method, theoretical calculation and operation modal testing are fused, so that the modal frequency of the reaction wheel system can be more comprehensively obtained, damage of a force measurement method to the reaction wheel and modal distortion in simulation are avoided, the recognition error of a harmonic coefficient is reduced, the fitting precision of high-order harmonics is improved according to multi-order resonance response characteristics, and the recognition accuracy of the reaction wheel system is improved. Therefore, the contribution of the reaction wheel vibration source component and the structure thereof under transmission can be effectively evaluated.

The invention relates to a power distribution network harmonic analysis method and system, and the method comprises the steps: constructing a digital twinborn model of a power distribution network region, and selecting transformers in the region as analysis objects one by one; for each analysis object, various working conditions are simulated by changing the transformation ratio of the analysis object in a digital twin model, and voltage and current waveforms are collected and subjected to Fourier decomposition to obtain harmonic phasors; thirdly, performing phase reduction on the phasor data, separating a real part from an imaginary part to construct a matrix, and solving a harmonic coefficient matrix by using a least square method to realize error minimization; separating linear and nonlinear parts of the harmonic current, and calculating a harmonic emission capability parameter and a harmonic current risk parameter for quantitative evaluation; according to the method, all transformers are traversed and analyzed, and systematic harmonic evaluation of the whole power distribution network area is finally realized.

The invention provides a spatial audio processing method of a volume sound source, spatial audio processing equipment of the volume sound source and a computer readable storage medium. The spatial audio processing method for the volume sound source comprises the following steps: acquiring first position information, a first geometric feature and a first acoustic feature of the sound source, second position information, a second geometric feature and a second acoustic feature of a shielding object, and third position information of a listener to perform ray tracing; determining the projection position of each tracking light on the spherical surface of the listener and the energy intensity corresponding to the projection position according to the light tracking result; determining a spherical harmonic coefficient of the sound source according to the projection position of each tracking light on the spherical surface of the listener and the corresponding energy intensity, so as to generate a multi-channel filter; and filtering a point sound source signal of the sound source using the multi-channel filter to generate a volumetric sound source signal conforming to the first geometric feature.

This invention provides a physical data signal processing method, apparatus, computer equipment, and storage medium. The method is based on a bispectral operation-based signal reconstruction approach. It calculates the harmonic coefficients, phase angle, and number of harmonic terms of the original signal's harmonic expression, as well as the harmonic coefficients, phase angle, and number of harmonic terms of the harmonic coefficients of the original signal's harmonic expression. Then, it reconstructs the harmonic coefficients of the original signal's harmonic expression and the original signal. During the reconstruction of the harmonic coefficients of the original signal's harmonic expression, the sample spacing of the harmonic coefficients is amplified, effectively increasing the dominant frequency of the physical data signal. This invention is applied to seismic exploration, effectively increasing the dominant frequency of the seismic wavelet signal, thus creating favorable conditions for improving the resolution of seismic exploration.

This invention discloses a method, system, and storage medium for identifying the surface wind pressure aerodynamic derivative that quantifies the contribution of aerodynamic instability to geometric shapes. The method includes: simultaneously acquiring the surface wind pressure time history and vibration displacement time history of the structural cross-section; processing the displacement signal to obtain the vibration frequency, amplitude, and phase difference; processing the wind pressure signal to obtain the wind pressure coefficient amplitude and phase difference at each measuring point; based on the theory of self-excited aerodynamics, establishing an explicit analytical formula through harmonic coefficient matching, and calculating the surface wind pressure aerodynamic derivative at each measuring point; analyzing the aerodynamic derivative at each measuring point, evaluating the contribution of each surface region to the overall aerodynamic derivative, and identifying key aerodynamic regions that excite or suppress self-excited vibrations. This invention degrades traditional macroscopic aerodynamic derivatives to spatial micro-elements, establishing a spatial mapping analytical closed chain between local wind pressure and aerodynamic derivatives, realizing spatial visualization and quantitative traceability of aerodynamic stability contributions, and providing a direct basis for targeted optimization of wind resistance for complex cross-sectional structures.

The invention discloses a single-stage gear parametrically-excited vibration response frequency spectrum prediction method based on modulation feedback, and the method comprises the steps: building a single-degree-of-freedom kinetic equation containing time-varying meshing stiffness based on the Newton second law, and solving a main oscillation frequency through employing a modulation feedback theory and a trigonometric series approximation method; constructing a quantitative prediction model of excitation parameters and dominant side frequency orders on the basis of a first-class Bessel function, and solving system response by applying a four-order Runge-Kutta method in combination with fast Fourier transformation to verify the prediction model; a parameter sensitivity analysis framework is established through a harmonic coefficient method, and the influence of excitation parameters on the main oscillation frequency and the side frequency amplitude ratio is quantified.

The invention discloses a sound source localization method based on same-order relative circular harmonic coefficients. The method is used for solving the singular problem of an open type circular array in a Bessel zero frequency interval and a high-order low-frequency range. When a circular harmonic domain characteristic wave beam is processed, mode intensity compensation is usually adopted to eliminate dependence on array characteristics. However, the problem of singularity exists in the frequency with very small modal intensity amplitude. In combination with the same-order mode intensity consistency characteristic, a new positioning feature same-order relative circular harmonic coefficient is designed, dependence on microphone array characteristics is removed, and the influence of a singular problem on a positioning result is also solved. The positioning algorithm provided by the invention has relatively low calculation complexity, and can be efficiently deployed on a hardware platform with limited resources. On the basis of keeping low calculation complexity, the method still shows excellent positioning precision in a high-noise and high-reverberation environment.

The invention provides a Chinese lute string fundamental frequency determination method and system, and the method comprises the steps: carrying out the time-frequency conversion of an audio signal, extracting a spectrum peak value, carrying out the energy weighting of the peak value according to a preset harmonic attenuation function, setting a candidate fundamental frequency set, constructing a preliminary harmonic cluster based on an initial non-harmonic coefficient, selecting a cluster with the highest energy, and calculating a real-time non-harmonic coefficient; and reconstructing candidate harmonic clusters according to the coefficient, and evaluating each harmonic cluster from two aspects of harmonic energy continuity and time domain correlation: calculating the sum of harmonic energy and combining with missing penalty to obtain an energy continuity score, and obtaining a time correlation score through a time cross-correlation mean value of fundamental frequency and each harmonic component energy envelope; and a comprehensive score is obtained after weighted summation.

The present application relates to the technical field of transformer design, and discloses a capacity determination method, system, medium and equipment of a double anti-star type transformer, the method comprising: obtaining a load loss set of a reference transformer under fundamental working conditions of a to-be-designed transformer, and each harmonic current effective value of the reference transformer under harmonic working conditions of the to-be-designed transformer; determining a harmonic coefficient set of the reference transformer under the harmonic working conditions of the to-be-designed transformer according to the harmonic current effective value and the load loss set; determining a capacity increase coefficient for quantifying the influence of the harmonic working conditions on the capacity of the reference transformer according to the load loss set and the harmonic coefficient set; and determining the capacity of the to-be-designed transformer according to the capacity increase coefficient. The present application can accurately calculate the loss caused by harmonics based on actual harmonic working conditions on site, thereby reasonably determining the transformer capacity and ensuring the operation reliability of the transformer under harmonic working conditions.

Embodiments according to the present invention comprise a signal feature determiner, e.g. a calculator or estimator, wherein the signal feature determiner is configured to determine information on a feature of a soundfield, e.g. a direction of arrival information or a diffuseness information, based on higher order, e.g. order larger than one, spherical harmonic coefficients, also designated as SHC, of a sound pressure, e.g. p(k), and / or SHC of a particle velocity, and based on a spherical harmonic order dependent weight, e.g. a weight g of a determination matrix G, wherein p(k) may, for example, form the basis of p (k). Further embodiments of the present invention comprise a signal feature determiner configured to determine information on a feature of a soundfield based on higher order circular harmonic coefficients of a sound pressure and / or a particle velocity and based on a circular harmonic mode dependent weight. Further embodiments relate to an audio encoder, a method and a computer program.

The invention discloses a helicopter body vibration active control method under time-varying vibration load excitation, and aims to solve the problems of poor environment tracking performance, reduced control effect and the like of helicopter vibration active control under large-range time-varying rotor vibration load. And a fluctuation harmonic control algorithm for reconstructing a fluctuation harmonic primary function by identifying an excitation response harmonic coefficient is provided, so that the aim of efficiently controlling the vibration of the machine body under the condition of large-range time variation of the vibration load of the rotor wing is fulfilled. The method has an efficient vibration environment real-time tracking capability, and can realize the control effects of high efficiency, high adaptability and high vibration environment tracking performance when the vibration load is subjected to large-range time varying.

This invention provides a method for evaluating the harmonic attenuation effect of radial electromagnetic force on a motor, belonging to the field of electromagnetic force harmonic technology. The method includes: first, collecting sensor data on the motor's magnetic flux density, vibration, current, and torque; constructing a measurement vector; and segmenting the data according to a sliding time window. Then, establishing a coupled electromagnetic field and mechanical structure model, discretizing it using the finite element method, and calibrating the model parameters using the measurement data. Calculating the harmonic coefficient matrix of the radial electromagnetic force using the magnetic flux density data, and establishing a dynamic model of the motor rotor system. Inputting the standard harmonic coefficients and wave harmonic coefficients into the dynamic model to obtain the corresponding vibration response matrices, and defining the harmonic attenuation coefficient matrix. Finally, training a neural network model that can quickly predict the attenuation effect of standard harmonics and wave harmonics, perform quantitative analysis, and output a comprehensive evaluation result. This method solves the problem that existing evaluations often involve extensive experiments, which are time-consuming and labor-intensive.