Flaw classification in ultrasonic guided waves signal using Wavelet Transform and PNN classifier

In this paper, a synthesized algorithm for flaw classification in ultrasonic guided waves signal is presented, in which Wavelet Transform is utilized in the process of noise suppression and envelop extraction, and the Probabilistic Neural Network (PNN) is introduced for flaw classification of the ultrasonic testing signal. Besides, in the process of feature extraction, the necessity of attenuation correction and feature selection of ultrasonic signal is discussed. The comparison of the performances of PNN and BP classifier is made in the last chapter, which demonstrates that the performance of flaw classification is significantly improved by the synthesized algorithm presented in this paper.