Fault Diagnosis of Gear Wearing Based on Order Cepstrum Analysis

2014 ◽  
Vol 543-547 ◽  
pp. 922-925 ◽  
Author(s):  
Hao Tian ◽  
Xiao Yong Kang ◽  
Yong Jian Li ◽  
Jun Nuo Zhang
Keyword(s):  
Time Domain ◽  
Processing Method ◽  
Vibration Signals ◽  
Cepstrum Analysis ◽  
Signal Processing Method ◽  
Start Up ◽  
Rotary Mechanism ◽  
Speed Up ◽  
Stationary Vibration ◽  
The Time Domain

The article explored a new signal processing method called order cepstrum analysis, it can analyze the instantaneous signals of the rotary mechanism, and can process the non-stationary vibration signals such as speed up or speed down signals effectively. Firstly, the start-up vibration signals of the gearbox are sampled at constant time increments in time-domain, then the data are resampled with software at constant angle increments in angle-domain. Therefore, the time domain instantaneously signal is changed into angle domain stationary signal. Then, the stationary signal is analyzed by order cepstrum. From the result we can find that it can avoid the frequency fuzzy phenomenon effectively, which cannot be solved with the traditional frequency spectrum analysis.

scholarly journals Vibrations in CDFW

Entropy ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 704
Author(s):  
Daniel Soares de Alcantara ◽  
Pedro Paulo Balestrassi ◽  
José Henrique Freitas Gomes ◽  
Carlos Alberto Carvalho Castro
Keyword(s):  
Time Domain ◽  
Low Frequency ◽  
Welding Process ◽  
Statistical Characteristics ◽  
Crest Factor ◽  
Vibration Signals ◽  
Mode Decomposition ◽  
Complex Process ◽  
The Time Domain ◽  
Peak Value

Continuous drive friction welding is a solid-state welding process that has been experimentally proven to be a fast and reliable method. This is a complex process; deformations in the viscosity of a material alter the friction between the surfaces of the pieces. All these dynamics cause changes in the vibration signals; the interpretation of these signals can reveal important information. The vibration signals generated during the friction and forging stages are measured on the stationary part of the structure to determine the influence of the manipulated variables on the time domain statistical characteristics (root mean square, peak value, crest factor, and kurtosis). In the frequency domain, empirical mode decomposition is used to characterize frequencies. It was observed that it is possible to identify the effects of the manipulated variables on the calculated statistical characteristics. The results also indicate that the effect of manipulated variables is stronger on low-frequency signals.

Convolutive Blind Source Separation Based on Wavelet De-Noising

2013 ◽  
Vol 756-759 ◽  
pp. 3356-3361 ◽  
Author(s):  
Hong Bin Zhang ◽  
Peng Fei Xu
Keyword(s):  
Blind Source Separation ◽  
Time Domain ◽  
Source Separation ◽  
Noise Pollution ◽  
Processing Method ◽  
Separation System ◽  
Communication Signals ◽  
The Time Domain ◽  
Ica Algorithm ◽  
Convolutive Blind Source Separation

The paper discusses the time-domain blind seperation applied to communication signals, using an ICA algorithm EFICA together with a wavelet de-noising processing method. In the Blind source separation system, regardless of the mixed signals and separated signals, noise pollution occurs frequently, it increases the complexity of BSS and the difficulty of dealing with the aftermath. So an automatic method of and wavelet de-noising processing is proposed finally. It yields good results in the experiment and improves the performance of BSS system.

scholarly journals Three-Dimensional Anisotropic Inversions for Time-Domain Airborne Electromagnetic Data

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Yang Su ◽  
Changchun Yin ◽  
Yunhe Liu ◽  
Xiuyan Ren ◽  
Bo Zhang ◽  
...  
Keyword(s):  
Time Domain ◽  
Three Dimensional ◽  
Model Parameters ◽  
Anisotropic Model ◽  
Regularized Inversion ◽  
Earth Structures ◽  
Airborne Electromagnetic ◽  
Speed Up ◽  
The Time Domain ◽  
Airborne Electromagnetic Data

Rocks and ores in nature usually appear macro-anisotropic, especially in sedimentary areas with strong layering. This anisotropy will lead to false interpretation of electromagnetic (EM) data when inverted under the assumption of an isotropic earth. However, the time-domain (TD) airborne EM (AEM) inversion for an anisotropic model has not attracted much attention. To get reasonable inversion results from TD AEM data, we present in this paper the forward modeling and inversion methods based on a triaxial anisotropic model. We apply three-dimensional (3D) finite-difference on the secondary scattered electric field equation to calculate the frequency-domain (FD) EM responses, then we use the inverse Fourier transform and waveform convolution to obtain TD responses. For the regularized inversion, we calculate directly the sensitivities with respect to three diagonal conductivities and then use the Gauss–Newton (GN) optimization scheme to recover model parameters. To speed up the computation and to reduce the memory requirement, we adopt the moving footprint concept and separate the whole model into a series of small sub-models for the inversion. Finally, we compare our anisotropic inversion scheme with the isotropic one using both synthetic and field data. Numerical experiments show that the anisotropic inversion has inherent advantages over the isotropic ones, we can get more reasonable results for the anisotropic earth structures.

Fault features analysis of a compound planetary gear set with damaged planet gears

2017 ◽  
Vol 232 (9) ◽  
pp. 1586-1604 ◽  
Author(s):  
Guoyan Li ◽  
Fangyi Li ◽  
Haohua Liu ◽  
Dehao Dong
Keyword(s):  
Time Domain ◽  
Planetary Gear ◽  
Significant Feature ◽  
Time Interval ◽  
Time Varying ◽  
Mesh Stiffness ◽  
Vibration Signals ◽  
Fault Features ◽  
Fault Properties ◽  
The Time Domain

The fault properties of compound planetary gear set are much more complicated than the simple planetary gear set. A damaged planet will induce two periodic transient impulses in the raw signals and generates modulation sidebands around the mesh harmonics. This paper aims to investigate the fault properties of a compound planetary gear set in damaged planet conditions. A dynamic model is proposed to simulate the vibration signals. The time interval between the fault-induced close impulses in the time domain is used as a significant feature to locate the faulty planet. Considering the phase relations, the time-varying mesh stiffness is obtained. Then, the fault properties are demonstrated in the simulation, and the theoretical derivations are experimentally verified.

The Method Based on Pattern Filter for Sonnd & Vibration Signal

2013 ◽  
Vol 333-335 ◽  
pp. 526-530
Author(s):  
Miao Rong Lv ◽  
Bao Jian Wei ◽  
Jian Lu ◽  
Jian Bo Diao
Keyword(s):  
Signal Processing ◽  
Model Building ◽  
Fourier Method ◽  
Vibration Signal ◽  
Complete Separation ◽  
Processing Method ◽  
Signal Extraction ◽  
Filter Method ◽  
Vibration Signals ◽  
Signal Processing Method

The difficulty of the signal processing is not the acquisition of the signals, but how to get the reasonble interpretations from the signals. Since the 1960s, Wavelet Transform, Fast Fourier method and other theoryies have done some works by some innovative processing methods to achieve a breakthrough. But for their limitions, these methods can not achieve a complete separation if the there are two or more signals in one time domain or frequency domain. In this article, a new engineering signal processing method-pattern filter method has is introduced, by which the signal extraction, sepration and noise reduction can be achieved successfully. Experiments show that this method can not only make a reasonable separation of the various vibration signals, but also give the typical signal extractions and model building ways.

scholarly journals Iterative variational mode decomposition and extreme learning machine for gearbox diagnosis based on vibration signals

2019 ◽  
Vol 13 (1) ◽  
pp. 4477-4492
Author(s):  
M. Firdaus Isham ◽  
M. Salman Leong ◽  
L. M. Hee ◽  
Z. A. B. Ahmad
Keyword(s):  
Signal Processing ◽  
Fault Diagnosis ◽  
Extreme Learning Machine ◽  
Processing Method ◽  
Mode Number ◽  
Variational Mode Decomposition ◽  
Vibration Signals ◽  
Signal Processing Method ◽  
Mode Decomposition ◽  
Learning Machine

Vibration-based monitoring and diagnosis provide an excellent and reliable monitoring strategies for maintaining and sustaining a million dollars of industrial assets. The signal processing method is one of the key elements in gearbox fault diagnosis for extracting most useful information from raw vibration signals. Variational mode decomposition (VMD) is one of the recent signal processing methods that helps to solve many limitations in traditional signal processing method. However, pre-determine the input parameters especially the mode number become a challenging task for using this method. Then, this study aims to propose an iterative approach for selecting the mode number for the VMD method by using the normalized mean value (NMV) plot. The NMV value is calculates based on the ratio of a summation of VMD modes and the input signals. The result shows that the proposed iterative VMD approach can select an accurate mode number for the VMD method. Then, the vibration signals decomposed into different VMD modes and used for gearbox fault diagnosis. Statistical features have been extracted from the selected VMD modes and pass into extreme learning machine (ELM) for fault classification. Iterative VMD-ELM provide significance improvement of about 20% higher accuracy in classification result as compared with EMD-ELM. Hence, this research study offers a new mean for gearbox diagnosis strategy.  

Research on the Dynamic Characteristic of the Bogie in Dynamic Track Stabilizer under the Excitation of the Track Irregularities

2012 ◽  
Vol 178-181 ◽  
pp. 1438-1441
Author(s):  
Li Hua Wang ◽  
Guang Wei Liu ◽  
An Ning Huang ◽  
Ya Yu Huang
Keyword(s):  
Spectral Density ◽  
Dynamic Characteristic ◽  
Time Domain ◽  
Large Scale ◽  
Degree Of Freedom ◽  
Speed Up ◽  
Critical Components ◽  
The Time Domain ◽  
Six Degree Of Freedom ◽  
Track Irregularities

With the large-scale speed-up of the railway, the dynamic track stabilizer will play an important role on the track overhauling and railroading of new line in our country. Bogie is one of the major critical components of the dynamic track stabilizer; its vibrating characteristic will affect the vibrating characteristic of the dynamic track stabilizer directly. The method of numerical simulate was used, based on the spectral density of the track irregularities, the time domain loads of the track irregularities were gained. Then the vibrating characteristics of the dynamic track stabilizer bogie under the excitation of the track irregularities were analyzed on the bases of the ANSYS/LS-DYNA. And the lateral, dilation, ups and downs, nod, swing and anti-rolling vibrating characteristics of the bogie on the six degree of freedom were obtained. The analysis results of this paper will provide foundation for the research on the stationarity and security of the dynamic track stabilizer.

Linear water waves: the horizontal motion of a structure in the time domain

2012 ◽  
Vol 709 ◽  
pp. 289-312 ◽  
Author(s):  
P. McIver
Keyword(s):  
Time Domain ◽  
Water Waves ◽  
Initial Conditions ◽  
Horizontal Motion ◽  
Floating Structure ◽  
Start Up ◽  
Specific Calculations ◽  
Linearized Theory ◽  
Infinitesimal Disturbance ◽  
The Time Domain

AbstractThe framework of the linearized theory of water waves in the time domain is used to examine the horizontal motion of an unrestrained floating structure. One of the principal assumptions of the theory is that an infinitesimal disturbance of the rest state will lead to an infinitesimal motion of the fluid and structure. It has been known for some time that for some initial conditions the theory predicts an unbounded horizontal motion of the structure that violates this assumption, but the possibility does not appear to have been examined in detail. Here some circumstances that lead to predictions of large motions are identified and, in addition, it is shown that not all non-trivial initial conditions lead to violations of the assumptions. In particular, it is shown that the horizontal motion of a floating structure remains bounded when it is initiated by the start up of a separate wave maker. The general discussion is supported by specific calculations for a vertical circular cylinder.

Sign in / Sign up

Export Citation Format

Share Document