Wavelet Packet Basis Optimal Selection in Compressing Vibration Signals of a Gearbox

In this paper, a compression algorithm of gearbox vibration signal combining wavelet packet transform is proposed. The effects of wavelet packet transform are also introduced and several main attributes of wavelet basis are analysed. Based on the description and discussion, a method to select wavelet basis of the compressing gearbox vibration signal is proposed. The paper represents a review of some recent patents regarding vibration signals. Experiment shows that, better SNRs of reconstruction signal can be obtained by using wavelet basis with low vanishing moment. Among those wavelet basis with low vanishing moment, the best signal-to-noise ratio in the same compression ratio can be obtained by using ‘coif’ wavelet basis because of its best symmetry.