Wigner-Ville Distribution Based on EMD for Faults Diagnosis of Bearing

Abstract

Wigner-Ville distribution (WVD) is a joint time-frequency analysis for non-stationary signals. The main difficulty with the WVD is its bilinear characteristic which leads to cross terms in the time-frequency domain. Recently the technique of empirical mode decomposition (EMD) has been proposed as a novel tool for the analysis of nonlinear and non-stationary data. In this paper, key elements of the numerical procedure and principles of EMD are introduced. Wigner-Ville distribution based on EMD is applied in the research of the faults diagnosis of the bearing. Firstly, the original time series data is decomposed in intrinsic mode functions (IMFs) using the empirical mode decomposition. Then, the Wigner-Ville distribution for selected IMF is calculated. The signal simulation and experimental results show that Wigner-Ville distribution based on EMD can not only successfully eliminate the cross terms but also effectively diagnosis the faults of the bearing.