scholarly journals False Target Discrimination of Air Surveillance Radar Based on Track Velocity Modification and Frequency Spectrum Analysis

2014 ◽  
Vol 2 (3) ◽  
pp. 382-388
Author(s):  
Hua-bin Wang ◽  
Mu Xu ◽  
Cheng Wang ◽  
Qing-quan Zhao
Keyword(s):  
Frequency Spectrum ◽  
Spectrum Analysis ◽  
Frequency Spectrum Analysis ◽  
Target Discrimination ◽  
False Target ◽  
Air Surveillance ◽  
Air Surveillance Radar

Research on Shearer Rocker Gearbox Fault Location Based on Wavelet Envelope Demodulation

2014 ◽  
Vol 528 ◽  
pp. 210-216
Author(s):  
Zeng Qiang Wang ◽  
Hong Wei Ma ◽  
Mei Hua Tao ◽  
Xu Hui Zhang ◽  
Qing Hua Mao
Keyword(s):  
Fourier Transform ◽  
Frequency Spectrum ◽  
Spectrum Analysis ◽  
Fault Location ◽  
Vibration Signal ◽  
Morlet Wavelet ◽  
Frequency Spectrum Analysis ◽  
Mechanical Faults ◽  
Faults Diagnosis ◽  
Feature Frequency

To solve the problem of faults location for shearer rocker gearbox, the multiple sites vibration signal of faulty rocker gearbox are collected, as well as the Morlet wavelet envelope demodulation is applied to demodulate vibration signal and Fourier transform is used to carry out frequency spectrum analysis of vibration signal. Experimental results show that this method can effectively extract the faults feature frequency from complex vibration signal. The faults location result is consistent with actual faults part. This mean realizes to locate faults accurately. It provides an effective method for mechanical faults diagnosis of shearer.

Vibrational Monitoring of Nested Planetary Geartrain with Unground Pinion

2021 ◽  
Vol 263 (5) ◽  
pp. 1471-1487
Author(s):  
Jianxiong Feng ◽  
Yangfan Liu ◽  
Kai Ming Li
Keyword(s):  
Frequency Spectrum ◽  
Spectrum Analysis ◽  
Time History ◽  
Critical Factor ◽  
Planetary Gear ◽  
Gear Train ◽  
Frequency Spectrum Analysis ◽  
Vibration Strength ◽  
Automobile Transmissions ◽  
Modulation Sideband

The nested planetary gear train, which has two integrated single-stage planetary gearsets, is one of the newly developed compound gear train that has been successfully applied to the automobile transmissions. In the current study, a certain type of gear fault in the nested gear train, ungrounded pinion, is investigated using a non-destructive approach monitoring its vibration levels. A novel experimental test stand with open and vertical setup has been designed to collect the vibrational data by mounting the accelerometer directly to the gear clutches. Each of the two layers of the compound gear was tested separately. The measured vibrational data were processed with several signal processing techniques, which includes (a) frequency spectrum analysis, (b) time synchronous averaging (TSA) and (c) modulation sideband analysis. The experimental results show that the existence of the ungrounded pinion can be identified with the frequency spectrum analysis of the vibrational data. In addition, the modulation sidebands are also modeled using a modified version of the traditional technique of physical signal modeling. It is shown that the relative phase of the planet and the meshing vibration strength changed by the unground gear is the critical factor for determining the modulation sideband behavior. In addition, the location of the ungrounded pinion can also be determined by the time history processed by TSA.

Large optical rotation angles measurement using frequency spectrum analysis

Optik ◽  
2015 ◽  
Vol 126 (20) ◽  
pp. 2433-2435
Author(s):  
Jianghui Cao ◽  
Hongzhi Jia
Keyword(s):  
Frequency Spectrum ◽  
Spectrum Analysis ◽  
Optical Rotation ◽  
Frequency Spectrum Analysis

Fast Pattern Recognition Based on Frequency Spectrum Analysis Used for Intrusion Alarming in Optical Fiber Fence

2015 ◽  
Vol 42 (4) ◽  
pp. 0405010 ◽  
Author(s):  
王照勇 Wang Zhaoyong ◽  
潘政清 Pan Zhengqing ◽  
叶青 Ye Qing ◽  
蔡海文 Cai Haiwen ◽  
瞿荣辉 Qu Ronghui ◽  
...  
Keyword(s):  
Pattern Recognition ◽  
Optical Fiber ◽  
Frequency Spectrum ◽  
Spectrum Analysis ◽  
Frequency Spectrum Analysis

scholarly journals Terahertz frequency spectrum analysis with a nanoscale antiferromagnetic tunnel junction

2020 ◽  
Vol 127 (6) ◽  
pp. 063905 ◽  
Author(s):  
P. Yu. Artemchuk ◽  
O. R. Sulymenko ◽  
S. Louis ◽  
J. Li ◽  
R. S. Khymyn ◽  
...  
Keyword(s):  
Frequency Spectrum ◽  
Spectrum Analysis ◽  
Tunnel Junction ◽  
Terahertz Frequency ◽  
Frequency Spectrum Analysis

Spectrum Analysis of Infrasound Signal

2014 ◽  
Vol 644-650 ◽  
pp. 4334-4337
Author(s):  
Bin Wang
Keyword(s):  
Frequency Spectrum ◽  
Frequency Distribution ◽  
Spectrum Analysis ◽  
Sound Pressure ◽  
Power Level ◽  
Amplitude Spectrum ◽  
Frequency Component ◽  
Pressure Amplitude ◽  
Frequency Spectrum Analysis ◽  
Infrasound Signal

In this paper, frequency spectrum of infrasound signal collected was analyzed based on MATLAB. The infrasound power level of change with frequency distribution and the infrasound harmonic of each frequency component of the sound pressure amplitude can be made up judgment visually by frequency spectrum analysis and amplitude spectrum analysis, and thus we can obtain different conditions of infrasound properties scientifically and quantitatively.

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