基于极值波延拓的端点效应处理方法

为解决总体平均经验模态分解(ensemble empirical mode decomposition, EEMD)的端点效应问题,提出了一种基于极值波延拓的端点效应处理方法。该方法从波形匹配延拓的模板子波和寻优起始点着手,以最靠近端点处的极值波为模板子波,以与端点处极值点同型的极值点为匹配起始点,使寻优的目的性更强,过程更加优化。同时,提出了一种客观有效的端点效应评价方法--区域等分的端点效应评价指标,避开了数据长度的干扰,突出了端点效应的影响。通过对仿真和实测信号的应用分析,并与采用镜像对称延拓方法比较,证明了极值波延拓法对抑制端点效应的有效性。

Method based on extension of extreme wave in dealing with end effect

In order to solve the problem of end effect on ensemble empirical mode decomposition (EEMD), a new method based on extension of extreme wave in dealing with end effect is proposed. This method focuses on the template wavelet and the optimization starting point in waveform matching and extension. The nearest extreme wave is used to the endpoint as the template wavelet, and the same type extreme point with the one nearest is taken to the endpoint as the optimization starting point. With this method, the purpose of optimization is clearer and the process is more optimized. In the meantime, an objective and effective evaluation method of end effect is provided, which is the end effect evaluating indicator in equal parts. It effectively avoids the interference of data length, and highlights the influence of end effect. Through the application of the method based on extension of extreme wave in the simulation signal and measured signal, and comparing with the result of the mirrored symmetry extension method, it is proved that the method base on extension of extreme wave can effectively restrain the end effect.