EMD间歇信号的检测和提取方法

讨论了由于间歇信号嵌入导致经验模式分解结果出现模态混叠的现象,指出极值点序列幅值突变是产生模态混叠的根本原因.利用第一阶固有模态函数极值点间距的变化和信号极大值以及极小值序列值的变化,构建了两种间歇信号的判别方法,并讨论了间歇信号的边界延拓方式.在间歇信号识别的基础上,用局部经验模式分解的方法提取间歇信号.最后以实际算例证明了该方法的有效性.

Method for Detecting and Extracting Intemittency Signal in EMD

The reason to mode mixing in the result of empirical mode decomposition is discussed in respect of the variation of extremum series. The amplitude of the extremum series changes suddenly when there is intermittency signal, thus causing mode mixing. Two novel methods are proposed to detect intermittency signals on EDM. The first one is designed based on the variation of the distance between the extremum series of the first intrinsic mode function, and the second one is designed with local maximum and minimum series values of the signal. The boundary extending method for the intermittency signal is discussed, then the intermittency signal is extracted by local empirical mode decomposition. Finally, the example proves that the method is effective.