基于EMD和HT的轧机瞬态振动信号时频分析

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

为解决轧机非平稳瞬态冲击信号的瞬态时频分析难题,提出了基于EMD和Hilbert变换的瞬态振动信号时频分析方法,利用EMD方法提取信号的固有模态函数(IMF),再结合Hilbert变换(HT)求解瞬时频率,得到信号的Hilbert时频谱和Hilbert边际谱,从而得到信号的瞬态特征。通过对调频调幅仿真信号和轧机实测瞬态信号的时频分析,验证了该方法的可行性。

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.