Abstract: The local mean decomposition (LMD) is a newly self-adaptive time-frequency analysis method. Mode mixing phenomenon which makes the decomposition results distortion may be produced when LMD is performed. The filter bank structure of LMD in white noise is obtained by numerical experiments, and based on this, the ensemble local mean decomposition method (ELMD) is proposed to overcome the shortcomings of mode mixing. In ELMD, different white noise is added to the targeted signal. The noise-added signal is decomposed by using LMD. Several decomposed results is severed as the final decomposition result. The analytical results from simulated signal and experimental rotor local rub-impact signal demonstrate that the ELMD method can be used to improve the mode mixing of the original LMD method effectively.

Key words: Ensemble local mean decomposition, Filter bank, Local mean decomposition, Mode mixing, White noise