Abstract:

In order to identify and locate the main noise source of carpet tufting machines, a noise source identification method based on empirical mode decomposition (EMD) and energy characteristics of discrete wavelet transform (DWY) was proposed. Firstly, EMD was used to decompose the noise signal of a carpet tufting machine into a plurality of intrinsic mode functions. According to the correlation coefficients, the false component were removed for reconstructing the noise signal. Secondly, DWT was used to process the reconstructed signal by using db20 wavelet, and the energy ratio of each component was calculated. Then the components with larger energy ratio were extracted, and time-frequency characteristics thereof were analyzed. Finally, the vibration signals of the main components of a carpet tufting machine were measured with a fiber laser vibrometer. The locations os main noise sources were obtained by comparing analysis.  The results show that this method can effectively identify and locate the main noise source of a carpet tufting machine.

Key words: carpet tufting machine, noise source identification, empirical mode decomposition, discrete wavelet transform, energy characteristic