Application of wavelet transform to sewage sludge/coal mixtures DTG signal for denoise

摘要

Denoise methods in sewage sludge/coal mixtures Derivative Thermogravimetry (DTG) signal were stu died with wavelet transform (WT) at 20℃ min~(-1). Four parameters were regarded as evaluating indicator to est imate the effect of denoise. Maximum Entropy Method was used in signal power spectrum estimation. The fa ct that process results was related with threshold selecting rules was found. 'Sqtwolog rule' may be the best one in this processing. The different among Fourier low-pass filter, average method and WT during DTG sign al processing were compared. It was found that the noise signal removed from three methods above were whi te noise. Time shift (TS) was ineluctable in WT processing. It's value can be calculated with cross correlation function (CCF) between origin signal and denoise signal.