Research on Rub Impact Fault Diagnosis Method of Rotating Machinery Based on Wavelet Packet and Support Vector Machine

Rub-impact fault is a common fault of rotating machinery. It will bring serious damage to mechanical equipment. A new diagnosis method based on wavelet packet and support vector machine (SVM) is proposed. The maximal singular values of wavelet packet decomposition coefficients are extracted as robust feature vectors. A new multi-class SVM classifier is constructed in "one versus one" classification strategy and binary tree, which can recognize several patterns of faults after being trained. Meanwhile the way was used on the rub impact fault identification of dual-disk over-hung rotor-bearing system. Experimental results show that the fault patterns can be well identified after training by SVM and its average identification rate has reached 99.175%.