Analysis of Fault Diagnosis for Rolling Bearing Based on EMD and Local Smoothness Index

A new method based on EMD (empirical mode decomposition) and local smoothness index for rolling bearing fault diagnosis is proposed. With this method, the local smooth index of each IMF (intrinsic mode function) got by empirical mode decomposition is calculated, IMFs with smaller local smoothness index and smaller fluctuation of its smoothness index are selected to analysis with Hilbert envelope spectrum, and the method proposed overcomes blindness of choosing the IMFs with the common EMD envelope method. Factual fault signal of rolling bearing is analyzed; the fault frequency of the rolling bearing is identified accurately.