Order tracking demodulation analysis based on Ensemble Empirical Mode Decomposition and its applications to fault diagnosis

Based on the feature of vibration signal of rotating machinery in speed fluctuation processes which are combined by many modulated signals and the fault characteristic frequency of it is varied following the rotating speed, and in order to suppress the phenomenon of mode mixing, a new method combined Order Tracking analysis with Ensemble Empirical Mode Decomposition(EEMD) algorithm were proposed. First of all, the time domain vibration signal were resample and transformed into angle domain stationary signal by using the Order Tracking technique,and then, the resample signal in angle domain is decomposed into several Intrinsic Mode Function components self-adaptively with EEMD. Finally, the envelope demodulation analysis is used to deal with high order components in angle domain and the fault features can be obtained. The analysis results from the simulation and experimental signals of out-race fault in rolling bearing fully proved the effectiveness of the proposed method.