scholarly journals Two-Dimensional Impact Reconstruction Method for Rail Defect Inspection

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jie Zhao ◽  
Jianhui Lin ◽  
Jinbao Yao ◽  
Jianming Ding
Keyword(s):  
Vertical Vibration ◽  
Reconstruction Method ◽  
Two Dimensional ◽  
Analysis Method ◽  
Defect Inspection ◽  
Inspection Method ◽  
Vibration Signals ◽  
Time Frequency ◽  
On Line ◽  
The Impact

The safety of train operating is seriously menaced by the rail defects, so it is of great significance to inspect rail defects dynamically while the train is operating. This paper presents a two-dimensional impact reconstruction method to realize the on-line inspection of rail defects. The proposed method utilizes preprocessing technology to convert time domain vertical vibration signals acquired by wireless sensor network to space signals. The modern time-frequency analysis method is improved to reconstruct the obtained multisensor information. Then, the image fusion processing technology based on spectrum threshold processing and node color labeling is proposed to reduce the noise, and blank the periodic impact signal caused by rail joints and locomotive running gear. This method can convert the aperiodic impact signals caused by rail defects to partial periodic impact signals, and locate the rail defects. An application indicates that the two-dimensional impact reconstruction method could display the impact caused by rail defects obviously, and is an effective on-line rail defects inspection method.

scholarly journals Multiresolution analysis of vibration signals acquired from locomotive Diesel engine for classification of engine states basing on signal statistical parameters

2017 ◽  
Vol 168 (1) ◽  
pp. 68-72
Author(s):  
Piotr BOGUŚ ◽  
Mateusz CIESZYŃSKI ◽  
Jerzy MERKISZ
Keyword(s):  
Diesel Engine ◽  
Complex Analysis ◽  
Statistical Parameters ◽  
Vibration Signals ◽  
Time Frequency ◽  
Significant Difference ◽  
Before And After ◽  
On Line ◽  
Locomotive Diesel

The paper presents a method of classification of locomotive Diesel engine states basing on vibration signals taken from an engine body and using chosen statistical parameters calculated for the original signal and it wavelet multiresolution components. The researches presented in the paper concern estimation of an engine states before and after a general repair. The target application of the presented researches is an on-line diagnostic system which can complement standard OBD systems. To this purpose the applied methods should not base on complex analysis of some spectral, time-frequency or scalogram plots but rather on choosing single diagnostic parameters which are suitable for the fast on-line diagnostic. The results have showed the significant difference in distinguishing of engine work before and after a general repair using some chosen statistical parameters applied to vibration signals.

scholarly journals Wavelet Transform in Vibration Analysis for Mechanical Fault Diagnosis

1996 ◽  
Vol 3 (1) ◽  
pp. 17-26 ◽  
Author(s):  
W.J. Wang
Keyword(s):  
Wavelet Transform ◽  
Time Scale ◽  
Vibration Analysis ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Vibration Signals ◽  
Time Frequency ◽  
Special Cases ◽  
Mechanical Faults ◽  
Short Time

The wavelet transform is introduced to indicate short-time fault effects in associated vibration signals. The time-frequency and time-scale representations are unified in a general form of a three-dimensional wavelet transform, from which two-dimensional transforms with different advantages are treated as special cases derived by fixing either the scale or frequency variable. The Gaussian enveloped oscillating wavelet is recommended to extract different sizes of features from the signal. It is shown that the time-frequency and time-scale distributions generated by the wavelet transform are effective in identifying mechanical faults.

scholarly journals The impact of sampling time on peak capacity and analysis speed in on-line comprehensive two-dimensional liquid chromatography

2010 ◽  
Vol 1217 (36) ◽  
pp. 5700-5709 ◽  
Author(s):  
Lawrence W. Potts ◽  
Dwight R. Stoll ◽  
Xiaoping Li ◽  
Peter W. Carr
Keyword(s):  
Liquid Chromatography ◽  
Sampling Time ◽  
Peak Capacity ◽  
Two Dimensional ◽  
On Line ◽  
The Impact

Fault Diagnosis of Rotating Machinery Due to Clearance Using Hilbert-Huang Transform

2009 ◽  
Author(s):  
Yeon-Sun Choi
Keyword(s):  
Fault Diagnosis ◽  
Rotating Machinery ◽  
Analysis Method ◽  
Hilbert Huang Transform ◽  
Time Frequency ◽  
Frequency Information ◽  
Stationary Signals ◽  
Signal Processing Methods ◽  
The Impact ◽  
Conventional Signal

The faults in rotating machinery, caused by the clearance between the rotor and the stator, commonly lie on partial rub and looseness. These problems cause malfunctions in rotating machinery since they create strange vibrations coming from impact and friction. However, non-linear and non-stationary signals due to impact and friction are difficult to identify. Therefore, exact time and frequency information are needed for identifying these signals. For this purpose, a newly developed time-frequency analysis method, HHT(Hilbert-Huang Transform), is applied to the signals of partial rub and looseness from the experiment RK-4 rotor kit. Conventional signal processing methods such as FFT, STFT and CWT were compared to verify the effectiveness of fault diagnosis using HHT. The results showed that the impact signals were generated regularly when partial rub occurred but that intermittent impact and friction occurred irregularly when looseness occurred. The time and frequency information was represented exactly by using HHT in both cases, which makes clear fault diagnosis between partial rub and looseness.

A New Morphological Method for Faults Diagnosis of Rolling Element Bearings

2012 ◽  
Vol 152-154 ◽  
pp. 1539-1544
Author(s):  
Ya Bin Dong ◽  
Ming Fu Liao ◽  
Xiao Long Zhang ◽  
Yu Min He
Keyword(s):  
Morphological Features ◽  
Rolling Element Bearings ◽  
Analysis Method ◽  
Rotating Machines ◽  
Rolling Bearings ◽  
Vibration Signals ◽  
Morphological Method ◽  
Rolling Element ◽  
On Line ◽  
Faults Diagnosis

A new morphology analysis method had been proposed to effectively extract the impulse components in the vibration signals of defective rolling element bearings. In the method, the morphology operator had been constructed by average of the closing and opening operator. For the construction of structure element (SE), the flat and zero was adopted as the shape and the height of SE, respectively, and the element numbers of the SE was optimized by a new proposed criterion (called SNR criterion). Vibration signals of two defective rolling bearings with an outer and an inner fault respectively are employed to validate the proposed method and the results are compared with ones calculated by envelopment analysis method. It shows that the proposed method is effective and robust to extract morphological features, and can be used to the on-line diagnostics of rolling element bearings in rotating machines conveniently.

Analysis of Rail Traffic Measured Vibration Based on Hilbert-Huang Transform

2013 ◽  
Vol 787 ◽  
pp. 632-637
Author(s):  
Qiang Pei ◽  
Yan Chen
Keyword(s):  
Energy Spectrum ◽  
Vertical Vibration ◽  
Urban Traffic ◽  
Urban Rail Transit ◽  
Vibration Level ◽  
Strong Reaction ◽  
Vibration Signals ◽  
Hilbert Huang Transform ◽  
Time Frequency ◽  
Rail Traffic

The effective measures to solve the urban traffic problem is the development of urban rail transit, but its ambient noise and vibration problems have prompted a strong reaction, restricting the development of rail transport undertakings. Observations on Beijing rail traffic of the 13th line Huoying-Huilongguan segment of vibration signals analysis, and we can get the Empirical Mode Decomposition (EMD) of the measured vibration signals through the HHT method, we also can analysis of the Hilbert-Huang time-frequency spectrum, the marginal energy spectrum and the instantaneous energy spectrum. Study the propagation of vibration along the ground, in order to predict the vibration level along the track. Though the analysis we find that the vertical vibration level is much higher than the level of vibration, the analysis should be mainly based on vertical vibration, the environmental vibration level is gradually attenuated with the increasing of the distance away from the track centerline.

On-Line Determination of Texture in Deep Drawing Steel Sheet by Two-Dimensional X-Ray Diffraction

2012 ◽  
Vol 572 ◽  
pp. 322-327 ◽  
Author(s):  
An Min Yin ◽  
Quan Yang ◽  
Xiao Chen Wang ◽  
Fei He ◽  
You Zhao Sun
Keyword(s):  
Distribution Function ◽  
Orientation Distribution Function ◽  
Deep Drawing ◽  
Orientation Distribution ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
On Line ◽  
The Impact

This paper described the application of a diffraction system based on X-ray area detector on pole figure measurement as well as corresponding computation of orientation distribution functions and the principle of rapid measurement texture. The impact of calculates the orientation distribution function on the conditions of the two-dimensional X-ray diffraction was analyzed; this was illustrated by an example of deep drawing steel sheets texture measurement. ̙̈́˰͇̱̓˰̶̴̿̾ͅ˰̸̱̈́̈́˰̷̱̹͂̿̈́̈́̾˰̸̵̈́˰͇̈́̿˽̴̵̹̹̱̼̽̾̓̿̾˰̴̵̵̳̈́̈́̿͂˰̈́̿˰̸̵̈́˰̵̱̹̱̀̀͂̿̀͂̈́˰̂θ position then fix it, reduce the sample rotation; the texture determination time can be significantly reduced. Reduce the Measuring range of angle χ˰̴̱̾ φ˰̴̵̿̓˰̾̿̈́˰̶̶̵̱̳̈́˰̸̵̈́ calculation of orientation distribution function, it also can significantly reduce the measurement of diffraction data. Several technical problems appeared on the on-line determination of texture based on an X-ray two-dimensional detector system and the possibility to improve the measurement speed and accuracy in the industrial production applications were then discussed.

Influence of Distance from Blast Center on Time-Frequency Characteristics of Blast Vibration Signals

2014 ◽  
Vol 1033-1034 ◽  
pp. 444-448
Author(s):  
Ming Sheng Zhao ◽  
Xu Guang Wang ◽  
En An Chi ◽  
Qiang Kang
Keyword(s):  
Seismic Wave ◽  
Seismic Waves ◽  
Low Frequency ◽  
Open Pit ◽  
Blasting Vibration ◽  
Analysis Method ◽  
Vibration Signals ◽  
Frequency Bands ◽  
Time Frequency ◽  
Energy Property

The distance from the blast center will directly change the blasting seismic wave wave’s energy property and eventually influence the structure’s response to the wave. To study its influence on the time-frequency (t-f) characteristics of blasting vibration signals, the single-hole blasting vibration test was conducted in Jinduicheng Open Pit Mine. Based on the measured data, wavelet analysis was used to decompose the measured signals, and signal segments at different frequency bands were got. RSPWVD quadratic form time-frequency analysis method was applied to analyze the segments’ t-f characteristics, and the domain frequencies of the blasting seismic waves under different distances from the blast center and the energy distribution and duration of the frequency bands were collected. The results show that the distance from the blasting center has a big impact on the domain frequency of the blasting seismic wave. With the increasing of the distance, the domain frequency reduces, its duration extends, the percentage of energy at the low frequency in the total energy increases and the duration of the frequency band extends. The research results provide the analysis base for understanding the influence of the distance from the blast center on signals’ t-f characteristic and studying vibration resistance and vibration reduction.

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