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Rotary machine rotating speed fluctuation keyless phase order tracking method

A technology of rotational speed fluctuation and rotating machinery, applied in the measurement of ultrasonic/sonic/infrasonic waves, testing of machines/structural components, measuring devices, etc., it can solve the problems of inability to extract time-domain waveforms and poor calculation accuracy, so as to reduce the cost of fault diagnosis. , the effect of obvious amplitude and high calculation accuracy

Active Publication Date: 2021-07-16
TONGJI UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to provide a method to effectively eliminate the "spectrum ambiguity" caused by variable speed in order to overcome the defects of the above-mentioned prior art that require hardware equipment, have poor calculation accuracy, are only applicable to weak speed fluctuations, and cannot extract time-domain waveforms. Unfavorable effects, realize accurate and reliable fault diagnosis of rotating machinery under variable speed conditions, keyless phase order tracking method for rotating machinery speed fluctuations

Method used

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  • Rotary machine rotating speed fluctuation keyless phase order tracking method
  • Rotary machine rotating speed fluctuation keyless phase order tracking method
  • Rotary machine rotating speed fluctuation keyless phase order tracking method

Examples

Experimental program
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Effect test

Embodiment 1

[0150] like figure 1 As shown, it is a keyless phase order tracking method for the speed fluctuation of rotating machinery. Assuming that the variable speed vibration signal is x(t), the method specifically includes the following steps:

[0151] Step 1: Install a vibration acceleration sensor near the rotating machinery to collect the vibration acceleration signal x(t) during variable speed operation;

[0152] Step 2: Perform discrete short-time Fourier transform (STFT) on the collected signal to obtain the time-frequency expression TFR(t,f), which specifically includes the following steps:

[0153] Step 201: Set the window function length N W and Fourier points L F , to construct the corresponding window function g(t):

[0154]

[0155] In the formula, σ is the window function coefficient;

[0156] Step 202: Perform discrete short-time Fourier transform (STFT) on the variable speed vibration acceleration signal x(t) to obtain the time-frequency expression TFR(t,f):

...

Embodiment 2

[0241] like figure 2 As shown, it is a second embodiment of the keyless phase order tracking technology for rotational speed fluctuations of rotating machinery. The vibration simulation signal x(t) of the gearbox is constructed, and the instantaneous rotational frequency of the reference shaft is:

[0242] f(t)=[500+1000*sin(2π·0.1t)] / 50 (40)

[0243] The amplitude modulation and phase modulation functions caused by the fault are:

[0244]

[0245] The gearbox vibration signal x(t) is:

[0246]

[0247] The concrete implementation result of this embodiment is as follows:

[0248] Set the basic parameters of the variable speed vibration signal: the highest meshing frequency order K=2, the number of faulty gear teeth N=16, the amplitude of the kth order meshing frequency X k = 1, initial phase Signal sampling frequency Fs=4000Hz, sampling time t=5s, signal-to-noise ratio SNR=-6dB.

[0249] Using the fast Fourier transform (FFT) method, the gearbox vibration signal x...

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Abstract

The invention relates to a keyless phase order tracking method for rotating speed fluctuation of a rotating machine. The method comprises the following steps of acquiring a vibration acceleration signal of the rotating machine; carrying out discrete short-time Fourier transform to obtain a time-frequency expression; estimating an initial time-frequency ridge line of the time-frequency expression through a double-side rapid ridge line extraction method; through a variational nonlinear frequency modulation mode decomposition method, according to the vibration acceleration signal and the initial time-frequency ridge line, extracting a signal dynamic characteristic; carrying out Hilbert transform and unwinding calculation on the dynamic characteristics of the signal to obtain an instantaneous phase curve of a modal component, and then carrying out equal-angle resampling to obtain an angular domain signal; and windowing the angular domain signal, converting the angular domain signal into an order domain by using discrete Fourier transform, and carrying out spectrum analysis and realizing fault diagnosis. Compared with the prior art, the method can eliminate the adverse effect of frequency spectrum fuzziness caused by the change of the rotating speed without the help of hardware equipment such as a key phase trigger, and effectively carries out signal processing and fault diagnosis on the rotating machine with a remarkable variable-rotating-speed working condition.

Description

technical field [0001] The invention relates to the field of fault diagnosis of rotating machinery, in particular to a keyless phase order tracking method for rotating speed fluctuations of rotating machinery. Background technique [0002] Rotating machinery is the key equipment in the industrial sector, widely used in electric power, petrochemical, transportation, energy, aerospace and other fields. With the rapid development of modern industry and science and technology, high-speed train transmission system, wind power The representative rotating machinery is developing in the direction of large volume, centralized equipment, system automation, intelligent control, and high-speed operation. The service environment is harsher, the operating conditions are more complex and unstable, and the problem of failure and failure is more acute. Taking the failure data of various train systems of the Guangzhou Metro as an example during the three-year period, running part failures acc...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01M99/00G01H17/00
CPCG01M99/005G01M99/008G01H17/00
Inventor 牛刚赵弘扬姜源
Owner TONGJI UNIV
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