解相关EMD:消除模态混叠的新方法

模态混叠是制约希尔伯特-黄变换(Hilbert-Huang Transform,简称HHT)在工程上推广应用的一个主要难题,采用在经验模态分解(Empirical Mode Decomposition,简称EMD)过程中嵌入解相关操作有效解决了EMD过程中产生的模态混叠问题。模态混叠的本质是各本征模态函数(Intrinsic Mode Function,简称IMF)分量之间信息相互耦合,无法表征有意义的物理过程,因此可认为模态混叠现象是由于IMF之间不完全正交导致。根据零均值随机信号正交性与不相关具有等价关系,在EMD过程中嵌入解相关操作,可有效保证IMF之间的正交性,消除模态混叠。仿真信号处理结果证明了方法的有效性。

Decorrelation EMD:a new method of eliminating mode mixing

Mode mixing is one of the difficulties of HHT in engineering applications, and a new method that embedding decorrelation operator into EMD process for solving the mode mixing is proposed. The essence of mode mixing is the mutual coupling of the information of the IMFs which results in the IMFs cannot represent a meaningful physical process, and it can be considered that the mode mixing is caused by the IMFs are not completely orthogonal. For the orthogonality and the non-correlation of the random process is equivalent, embedding decorrelation operator into EMD process can improve the orthogonality of the IMFs effectively and eliminate mode mixing. The simulation results show the effectiveness of this method.