Method for determining number of modes of variational mode decomposition

Abstract

A method for determining the number of modalities of variational mode decomposition comprises the following steps: S1, initializing variational mode decomposition parameters, carrying out one-layer decomposition on a signal, and obtaining the center frequency of the first-layer decomposition; S2, adding 1 to the modal number K, and repeating the step S1 to obtain the center frequency of the Kth layer of decomposition; S3, calculating errors of all decomposed center frequencies of (K-1)th layer and Kth layer, and finding out stable center frequencies; S4, calculating an average value of the stable center frequencies, and finding out a dominant center frequency; s5, judging whether number of dominant center frequencies obtained by decomposition of Kth layer is greater than that of dominant center frequencies obtained by decomposition of (K-1)th layer; and if yes, repeating the steps S2 to S2; if not, stopping decomposition, and determining the number of modes as the number of dominant center frequencies. The invention aims to provide a simple, feasible, accurate and effective mode number determination method for variational mode decomposition, and the accuracy of variational mode decomposition and the effect of fault signal analysis are improved.

Description

technical field [0001] The invention belongs to the field of fault signal analysis, and in particular relates to a method for determining the number of modes of variational mode decomposition. Background technique [0002] Variational mode decomposition is an adaptive non-recursive signal processing algorithm. This method determines the center frequency and bandwidth of each frequency component of the signal by iteratively searching for the optimal solution of the variational model, and can adaptively realize the division and Efficient separation of the individual eigenmode function components. Compared with traditional recursive algorithms such as empirical mode decomposition, variational mode decomposition effectively alleviates mode aliasing and boundary effects, and has high computing efficiency and strong robustness. It has been widely used in fault The field of signal analysis. [0003] When performing variational modal decomposition, it is necessary to set six param...

AI Technical Summary

Problems solved by technology

The number of modes K determines the number of decomposition layers of the variational mode decomposition, which has a great influence on the decomposition results. The inaccurate value of K will lead to more noise contained in the obtained intrinsic mode function components, and the fault is periodic. The characteristic component is not obvious, which affects the analysis of fault signals

However, at present, the value of K lacks a unified theory and principle. It is generally determined based on experience or trial methods. Signal analysis does not work well

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