爆破地震波信号EMD端点效应抑制研究

Study on suppression of EMD endpoint effect of blasting seismic wave signal

针对爆破地震波信号经验模态分解(EMD)得到的IMF在端点处的发散现象,提出一种同时考虑信号端点发展趋势和全局时间-能量联合参数的改进EMD端点效应抑制算法。该算法首先考虑端点变化趋势得到延拓后的边界局部特征尺度X_0,再计算X_0的能量E_0,找到原始信号中和E_0最匹配的分段信号X_k,最后用X_k代替X_0进行EMD。通过建立仿真信号,验证该算法和常规端点效应抑制算法相比,对EMD端点效应具有更好的抑制能力,能够得到精度更高的IMF。最后将该算法用于实际爆破地震波信号分解中,发现提出的算法能够有效抑制EMD端点效应,有利于爆破地震波信号细节特征参数的提取。

Aiming at the divergence of IMF at the endpoint obtained by empirical mode decomposition(EMD)of blasting seismic wave signal,an improved EMD endpoint effect suppression algorithm considering the development trend of signal endpoint and global time-energy joint parameters is proposed.The algorithm first considers the endpoint change trend to obtain the extended boundary local characteristic scale X 0,then calculates the energy E 0 of X 0,finds the segmented signal X K that best matches E 0 in the original signal,and finally uses X K to replace X 0 for EMD.By establishing simulation signals,it is verified that the proposed algorithm has better suppression ability to EMD endpoint effect and can get more precise IMF than the conventional endpoint effect suppression algorithm.Finally,the proposed algorithm is applied to the decomposition of actual blasting seismic wave signals.It is found that the proposed algorithm can effectively suppress the EMD endpoint effect and is beneficial to the extraction of detailed characteristic parameters of blasting seismic wave signals.