波形匹配延拓是遏制经验模态分解（EMD）端点效应的有效方法，针对现有波形匹配延拓方法的不足，提出了一种自适应的三角波形匹配延拓方法，改进了三角波匹配度的计算方法和匹配子波的寻优算法。改进的三角波匹配度计算方法，突出延拓平顺性的同时，加强了端点处数据与内部波形的关联。自适应的匹配寻优算法，首先在固定极值点对应的波段内部搜寻局部最佳子波的截取时刻，截取局部最优匹配子波，然后在局部最优子波内搜寻全局最优匹配子波，提高了子波截取的合理性与匹配的准确性。仿真信号及实验信号分析表明，该方法可有效抑制EMD端点效应，显著提高分解精度。%Considering waveform matching extension is an effective method to improve the end effect of empirical mode decomposition (EMD).Aiming at deficiencies of existing matching extension methods,a self-adaptive triangular waveform matching extension method was proposed for EMD here.With this method,both the matching level algorithm of triangular waveform and the searching algorithm for optimal triangular waveform were improved.Using the new matching level algorithm not only promoted the extension's smoothness but also enhanced the relationship between the data near the end-point and the waveform inside.The new searching algorithm was used to search for an intercepting instant to cut out the local optimal wavelet in each wave band corresponding to the fixed extreme value point,and then to search for the global optimal wavelet in local optimal wavelets.The simulated signals and experimental signal analyses showed that the proposed method can effectively mitigate the end effects of EMD and significantly improve the precision of decomposition.
展开▼
