Characterized wavelet construction based on lifting scheme and its applications
Duan Chen-dong · 2007
In order to get a characterized wavelet with expected properties of fault features extraction,by using the lifting scheme(LS),a new wavelet is constructed.The low-pass filter of cubic B-splines wavelet transform is employed as an initial filter,and on the basis of the principle of interpolating subdivision,a lifting operator is designed,and then the new wavelet is obtained through one lifting step according to the LS framework.The wavelet inherits the property of low-pass filtering that the initial filter possessed,and has the ability to extract transient impulse component.By making an equivalent exchange to the LS framework and removing the decimator,an algorithm for undecimated wavelet transform(UWT) based on LS is proposed,through which,fault features of friction in a compressor gearbox and impact-rub in a pressure cylinder were effectively extracted.Engineering applications show that decomposition results of UWT can provide much more plenty diagnostics information than the classical wavelet transform.