Wavelet analysis of acoustic emission signals in boring

Using acoustic emission (AE) signals to monitor tool wear states is one of the most e€ective methods used in metal cutting processes. As AE signals contain information on cutting processes, the problem of how to extract the features related to tool wear states from these signals needs to be solved. In this paper, a wavelet packet transform (WPT) method is used to decompose continuous AE signals during cutting; then the features related to tool wear states are extracted from decomposed AE signals. Experimental results veri®ed the feasibility of using the WPT method to extract features related to tool wear states in boring.