Method of eliminating influence of comb-spectrum noise upon vibrational energy level

A vibration energy level, comb spectrum technology, applied in speech analysis, instruments, etc., can solve problems such as poor practicability

Active Publication Date: 2015-05-06
中国船舶重工集团公司第七〇五研究所
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] In order to overcome the disadvantages of poor practica

Method used

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  • Method of eliminating influence of comb-spectrum noise upon vibrational energy level
  • Method of eliminating influence of comb-spectrum noise upon vibrational energy level
  • Method of eliminating influence of comb-spectrum noise upon vibrational energy level

Examples

Experimental program
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Effect test

Embodiment 1

[0041] This example is based on the vibration data and performance data simulation obtained data containing noise at equal intervals, by filtering the comb spectrum noise with an interval of 10 Hz, and calculating the vibration energy level after the interference is eliminated. The sampling frequency of the simulated vibration data is 100Hz, and the number of sampling points is 2048. The center frequency f of the 1 / 3 octave spectrum used c The distribution is as follows,

[0042] f c=[1,1.25,1.6,2,2.5,3.15,4,5,6.3,8,10,12.5,16,20,25,31.5,40,50]

[0043] Specific steps are as follows:

[0044] Step 1, for the simulated signal x(t), according to

[0045] X ( ω ) = ∫ 0 20.47 x ( t ) e - jωt dt - - - ...

Embodiment 2

[0077] The power test of the power plant is the most effective test method to comprehensively test the performance of the power plant on land. Once a certain assessment indicator fails to meet the standard, the test will be redone, which will increase the cost and delay the progress, or it will be classified as a substandard product, causing heavy economic losses to the factory. Vibration is one of the most important evaluation indicators of power test. Due to the limitation of field test conditions, vibration measurement data inevitably contains various disturbances.

[0078] In a field test, the vibration signals of several power test evaluation points in a period of time contain periodic interference with an interval of 100 Hz. The excitation frequency of the mechanical motion of the power unit is equal to the fractional or integer multiple of the engine rotation frequency. When the rotation frequency of the engine changes, the excitation frequency of the mechanical motion ...

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Abstract

The invention discloses a method of eliminating influence of comb-spectrum noise upon vibrational energy level and aims to solve the technical problem that the existing method of eliminating the comb-spectrum noise is poor in practicality. According to the technical scheme, the method includes: determining related technical parameters, and constructing a corresponding band-pass filter with a Fourier kernel function as a primary function; adding a frequency-shifting factor to obtain a comb band rejection filter which is satisfactory; combining a power spectrum of an original signal and the constructed comb band rejection filter, and filtering, under a frequency domain, periodic interfering components in the original signal; according to post-filtering spectral amplitude, performing calculating to obtain power spectral density, and performing calculating with the power spectral density according to a frequency band to obtain a one-third octave band spectrum. The method has the advantages that interfering signals distributed at equal intervals can be filtered; the vibrational energy level is directly calculated under the frequency domain, repeated testing done for false vibration alarm can be avoided by correcting the false alarm on the vibrational energy level, caused by interfering noise; test cycle can be shortened; the method is highly practical.

Description

technical field [0001] The invention relates to a method for eliminating comb spectrum noise, in particular to a method for eliminating the influence of comb spectrum noise on vibration energy level. Background technique [0002] 1 / 3 octave spectrum is a frequency domain analysis method constructed according to the response characteristics of the human ear to sound. It has the characteristics of few spectral lines and wide bandwidth. It is widely used in the analysis and processing of acoustic and vibration signals. The level value (vibration level / sound level) of the process is the main indicator for judging the size of vibration and noise. With increasing concerns about noise and vibration, the octave method has been continuously improved. The Chinese patent "Method for Directly Obtaining Octave Spectrum Array with Multiple Measuring Points Adjacent to the Same Working Condition (Patent No. ZL 201110012751.1)" authorized in 2014 provides a comprehensive overview of the re...

Claims

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Application Information

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IPC IPC(8): G10L21/0232
Inventor 孙涛高慧中刘培培
Owner 中国船舶重工集团公司第七〇五研究所
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