Local mean decomposition method based on B spline interpolation
The local mean decomposition (LMD) is a relatively new approach of adaptive signal analysis.The core of LMD is to decompose an original signal into several production functions (PF),and each of which is a product of an envelope function and a pure frequency modulated one.Both the local mean function and the envelope estimation of the signal need to be extracted in the LMD algorithm,while the conventional extraction approach brings the local error and a slow rate of decomposition.To solve these problems,a new approach for extracting the local mean and the envelope estimation using the cubic B spline interpolation (CBI) was proposed.The upper envelope and the lower envelope were obtained by using the CBI firstly,and then the local mean and the envelope estimation were extracted from these two envelopes.The comparative experiments between the simulated signals and the mechanical vibration signals verified the superiority of this new approach.