The invention relates to an extraction method for early failure sensitive characteristics based on ensemble empirical mode
decomposition (EEMD) and
wavelet packet transform. The extraction method for the early failure sensitive characteristics based on the EEMD and the
wavelet packet transform includes the following steps: (1), collected original vibration signals of mechanical and
electrical equipment are decomposed according to the EEMD,
white noise is added, and intrinsic mode function (IMF) components are obtained through
decomposition; (2), the sensitive IMF components closely related to failure are chosen, and other irrelative IMF components are ignored; (3), the sensitive IMF components chosen through step (2) are decomposed in an
orthogonal wavelet packet mode, and a
wavelet coefficient of each node is obtained; and (4), envelopes are extracted from the obtained wavelet packet coefficients by adoption of the Hilbert transform and the
Fourier transform, power spectrums are calculated, the power spectrum corresponding to each wavelet packet coefficient is obtained and serves as the early failure sensitive characteristic , and the sensitive characteristics are automatically obtained. Self-adapting signals can be decomposed, the sensitive characteristics can be convenient to obtain automatically, diagnosis precision and speed are improved, and a mechanical and electrical
system can be diagnosed quickly, accurately and stably. The extraction method for the early failure sensitive characteristics based on the EEMD and the wavelet packet transform can be applied to the field of mechanical and
electrical equipment failure diagnosis.