PCA-Based Method for Power Frequency Noise Suppression of Aircraft Duct Vibration Signal

Abstract

The invention discloses a PCA-based method for suppressing the power frequency noise of the vibration signal of an aircraft duct. The power frequency noise is estimated by performing PCA preprocessing on the vibration signal in the time window, and then the corresponding power frequency noise is obtained by estimating the power frequency noise. The noise parameters can then be used to obtain structural power frequency noise, and finally the vibration signal after noise suppression can be obtained by subtracting the structural power frequency noise from the vibration signal. The PCA-based power frequency noise suppression method for aircraft duct vibration signals disclosed by the present invention can suppress the power frequency noise in the duct vibration signals. It has a strong ability to protect signals when overlapping, and can effectively improve the signal-to-noise ratio of vibration signals.

Description

technical field [0001] The invention relates to the technical field of aircraft duct vibration signal noise reduction, in particular to a PCA-based method for suppressing industrial frequency noise of aircraft duct vibration signals. Background technique [0002] The sensors arranged on the aircraft duct can obtain the vibration signal after hammering the duct, but the vibration signal collected by the aircraft duct in the actual environment has power frequency noise, which seriously affects the judgment of the stress state of the aircraft duct. There are few literatures on the suppression method of power frequency noise of aircraft duct vibration signal. It is concluded that the current methods of suppressing power frequency noise mainly include frequency domain method and time domain method. In the doctoral thesis "Research on Electrostatic Monitoring Technology and Life Prediction Method in Rolling Bearing Wear Area", the notch method is used to suppress power frequency n...

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Problems solved by technology

In the doctoral thesis "Research on Electrostatic Monitoring Technology and Life Prediction Method in Rolling Bearing Wear Area", the notch method is used to suppress power frequency noise, but this method is easy to damage useful signals when the signal-noise spectrum is aliased; the article "Based on Harmonic Wavelet and SVD Suppression of Power Frequency Interference of Tilting Pad Sliding Bearings" using harmonic wavelet to extract power frequency bands for singular value decomposition to suppress power frequency noise, but this method ignores the instability of power frequency; the article "Based on spectral interpolation and singular value difference spectrum The denoising method of rolling bearing static monitoring signal" uses the spectral interpolation method to suppress power frequency noise, but this method is easy to filter out some useful signals when interpolating in the 48-52Hz interval; the article "Elimination of Power Frequency Interference in Vibration Signals Based on Independent Component Analysis" The independent component analysis method is used to suppress power frequency noise, but the noise suppression effect of this method depends on the number of observed signal sources; the article "Power Frequency Interference Elimination Method Based on Singular Vector Spectrum" uses the spectrum of singular value vectors to suppress power frequency noise, but the method While filtering out noise, some useful signals will also be filtered out; CN106895985A discloses "Fault Signal Noise Reduction and Reconstruction Feature Recognition Method for High-speed Wire Rolling Mill" proposes a method based on Fourier transform search to characterize the singular value of power frequency noise to suppress power frequency noise, but this method is only suitable for strong power frequency noise environment; the article "cosine function adaptive method to identify and eliminate single-frequency interference" uses the function approximation method to eliminate power frequency noise, but this method ignores the instability of power frequency;

[0003] CN104570118A discloses "a method for automatic identification and removal of industrial interference based on two factors", which proposes to use the sin-cosine weighted approximation method to deal with industrial interference, but this method is applicable to the situation of power frequency and stable amplitude; the article "Based on PCA, the most Optimum-order parallel source power frequency noise suppression" uses the relationship between principal components and power frequency numbers to filter out power frequency noise, but this method also has the problem of damaging useful signals when signal-to-noise frequencies alias; it can be seen that none of the above methods can It is fully suitable for the suppression of power-frequency noise of aircraft duct vibration signals, and pointed out that the existing research on PCA suppressing power-frequency noise has the problem of useful signal loss when the signal-to-noise frequency bands are mixed

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