In the practical application process, the selection of neighborhood radius has an important effect on the performance of local projection noise reduction method. An improved method was proposed to solve the difficult problem of the selection of neighborhood radius. In this method, according to the difference of frequency bands energy distribution, the vibration signal was decomposed into the noise frequency band and the system signal frequency band with wavelet packet method. The ratio of the energy of noise frequency band and the energy of vibration signal was estimated to be the noise level of vibration signal. In certain extent, the decomposition layers were increased gradually until the noise level converged. The neighborhood radius of reconstructed phase space can be estimated by the convergent noise level. In addition, the blind SNR of vibration signal can be estimated by the convergent noise level. The numerical simulations of noisy Lorenz and Rossler series show that the noise reduction effect of this method is better than some traditional methods and the local projection method based on recurrence quantification analysis. Noise reduction of reciprocating compressor vibration signal further shows the effectiveness of this method.
ZHANG Lai-bin;LI Feng;DUAN Li-xiang.
Local Projection Noise Reduction Method of Reciprocating Compressor Vibration Signal Based on Adaptive Estimation of Noise Level[J]. Journal of Vibration and Shock, 2010, 29(1): 53-57,9
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