Fault Feature Extraction of Gearbox Based on Wavelet and Wavelet Package

In this paper,a double filtering algorithm is proposed for de-noising of malfunction gearbox vibration signal,which is pro-duced by combining adaptive wavelet transform de-noising and wavelet De-noising by threshold.The de-noising process of this algo-rithm consist of two phases,at first phase,de-noising is implemented by adaptive wavelet transform.At the second phase,the clas-sical wavelet de -noising algorithm by threshold is used for the signal de -noising.At last,the de -noised signal is decomposed by wavelet package.The power of frequency bands is extracted as fault feature vector.