Fault diagnosis based on wavelet package and phase spectrum for helicopter rotor

Considering difficulty in extracting feature and localizing fault for helicopter rotor, a new method based on wavelet energy spectrum and phase spectrum is presented. The wavelet package analysis is adopted to eliminate the noise in the actual signals to increase signal-to-noise ratio, and to extract energy feature vector in various frequency bands through signal decomposition and single reconfiguration. And Fast Fourier Transform algorithm is applied to obtain initial phase. Rotor fault diagnosis and localization is realized by combining the wavelet energy feature vector with initial phase spectrum. Experiments results validate the effectiveness of this method.