Time-frequency analysis for rolling mill's transient vibration signal based on EMD and HT

For solving the problem of the transient time-frequency analysis in the non-stationary transient impact signal of the rolling mill,a novel signal analysis method based on EMD and Hilbert transformation(HT)was proposed by theory.First,the intrinsic mode function(IMF)of the signal is extracted by the empirical mode decomposition(EMD).Then,the instantaneous frequency is determined by the Hilbert transformation.Subsequently,the Hilbert time-frequency spectrum and the Hilbert boundary spectrum are obtained.Finally,the transient feature of the signal is gotten.The time-frequency analysis on the frequency-modulation and amplitude-modulation simulation signal and the measured transient vibration signal shows the feasibility of the method.