... measured on bearings by discrete wavelet transform and subsequently performs the Fourier transform on the wavelet coefficients. The effectiveness of such a unified technique is demonstrated through experimental case studies, which confirmed its advantage over the wavelet or Fourier transform techniques...

... is an approximation of the steepest descent algorithm ( 29 ) that is a simple but a slow minimization method. 29 06 2005 02 07 2008 13 02 2009 engine cylinders entropy feature extraction mechanical engineering wavelet transforms As machinery becomes more complex and costly...

... are preprocessed using Laplace-wavelet transform for features’ extraction. The extracted features for wavelet transform coefficients in time and frequency domains are applied as input vectors to artificial neural networks (ANNs) for rolling bearing fault classification. The Laplace-Wavelet shape and the ANN...

...Shuncong Zhong; S. Olutunde Oyadiji This paper proposes a new approach based on auxiliary mass spatial probing by stationary wavelet transform (SWT) to provide a method for crack detection in beamlike structure. SWT can provide accurate estimation of the variances at each scale and facilitate...

... of the processing of vibratory measurements. This processing can be made by temporal methods, frequential methods, or by time-scale methods using the wavelets for 2 decades. The wavelet transform is a very effective processing, however, the difficulties of application and interpretation of the results slow down...

... but the window bandwidth varies along frequency adaptively. The method therefore behaves more like an adaptive continuous wavelet transform. We use B-splines as the window functions, which have near optimal time–frequency localization, and derive a fast algorithm for adaptive time–frequency representation...

... conditions. These include steady synchronous forcing, step changes in synchronous forcing and multifrequency forcing produced by a rotor impact mechanism. 27 04 2005 07 02 2006 vibrations vibration control rotors adaptive control wavelet transforms control system synthesis three-term...

...Wen-xian Yang; Peter W. Tse The appearance of overlapping in the results derived by continuous wavelet transform (CWT) smears the spectral features and makes the results difficult to interpret. This will significantly affect the accuracy of analysis of anomalous signals. Aiming at minimizing...

...D. F. Shi; W. J. Wang; L. S. Qu In order to overcome the shortcomings in the traditional envelope analysis in which manually specifying a resonant frequency band is required, a new approach based on the fusion of the wavelet transform and envelope spectrum is proposed for detecting and localizing...

... to be effective in detecting gear faults when cyclostationary analysis by itself fails. acoustic filters automotive components wavelet transforms vibrations gears fault diagnosis mechanical testing Wavelet analysis and cyclostationary analysis have both been employed to detect fault symptoms...

...Jin-Wei Liang; Brian F. Feeny Wavelet transforms were compared between various simulated friction models and real stick-slip data. While simulations of several models produced stick-slip transition oscillations seen in the real data, the wavelet features of the compliant contact model with light...

... wavelet transforms acoustic signal processing machine bearings maximum likelihood estimation signal processing Gaussian noise vibrations Early fault detection in machines can save millions of dollars on emergency maintenance and production loss costs. Gearboxes and roller bearings...

... the response data of the corresponding nonlinear system. Two time-frequency filtering methods are discussed here. One is based on the quadratic time-frequency distribution and its inverse transform, the other is based on the quadratic time-frequency distribution and the wavelet transform. Both numerical...

... time-frequency analysis wavelet transforms nonlinear dynamical systems acoustic signal processing structural acoustics The identification of nonlinear systems has received considerable attention in recent years because most real structures exhibit some degree of nonlinearity. Various...

..., 20A . Gade, S., and Gram-Hansen, K., 1996, “Non-stationary Signal Analysis Using Wavelet Transform, Short-time Fourier Transform and Wigner-Ville Distribution,” Bruel & Kjaer Technical Review, No. 2. Dowling, H. M., 1993, “Application of Non-stationary Analysis to Machinery Monitoring...