The Open Automation and Control Systems Journal

2015, 7 : 1017-1021
Published online 2015 September 10. DOI: 10.2174/18744443015070101017
Publisher ID: TOAUTOCJ-7-1017

Feature Extraction Method of Ultrasonic Signal Based on Wavelet Coefficients Clustering

Feng Zhihong , Miao Changyun and Bai Hua
Engineering Practice Teaching Training Center, Tianjin Polytechnic University, Tianjin 300387, P.R. China.

ABSTRACT

Support Vector Machine can well solve the classification problem of small sample, but when the dimension of input feature vector is very large, the structure of classifier is complex, the training time is long, and the performance is decreased. To solve this problem, a feature extraction method based on wavelet coefficients clustering was proposed. All the wavelet coefficients were clustered, the energy value of wavelet coefficients in each clustering was calculated and used as the input feature vector of a classifier. The dimension of input data was greatly reduced and information of specific problem was reserved. Support Vector Machine was used to identify the defects in steel plate, experiment results showed that the proposed method has higher classification accuracy.

Keywords:

Feature vector, Feature extraction, Support vector machine, Wavelet transform.