基于HHT方法的典型地运动信号分析

Analysis of the typical ground motion signal based on the HHT

开展了基于含噪声Chirp信号及典型地运动信号的Hilbert-Huang变换(HHT)分析,给出了信号经EMD分解后的固有模态函数(IMF)及Hilbert变化得到的Hilbert谱和瞬时能量谱。结果表明,HHT法具有高时频分辨率和自适应强的特点,能很好的应用于地运动等非平稳信号的分析,分解得到的IMF分量按高频到低频进行排列,代表了信号在相应频率和时间段的特征,且原始数据重构结果良好,误差量级在10-18以上;且Hilbert变换得到的时频谱清晰的表明了信号能量随时间-频率的分布,能较好的反映地运动信号的传播规律。

In order to verify the superiority of the Hilbert Huang Transform(HHT)method in non-stationary signal analysis and obtain the time-frequency characteristics and energy distribution parameters of ground motion signals,HHT analysis based on noisy Chirp signals and typical ground motion signals was carried out.The inherent mode function(IMF)of the signal after EMD decomposition and the Hilbert spectrum and instantaneous energy spectrum obtained from Hilbert changes were presented.The results show that the HHT method has the characteristics of high time-frequency resolution and strong adaptability,and can be well applied to the analysis of non-stationary signals such as ground motion.The decomposed IMF components are arranged from high frequency to low frequency,representing the characteristics of the signal in the corresponding frequency and time period.The original data reconstruction results are good,with an error level of over 10-18;and the time-frequency spectrum obtained by Hilbert transform clearly indicates the distribution of signal energy with time frequency,which can better reflect the propagation law of ground motion signals.