Optimal features combination for pulsed eddy current NDT

Abstract

This paper investigates current feature extraction techniques for pulsed eddy current NDT including peak value and peak time, spectral characteristics analysis, principal component analysis (PCA) projection coefficient and response shape curvature. Experimental study has been undertaken on samples with artificial surface and subsurface defects and metal thickness changes. Based on a comparative study of the feature extraction techniques, the most suitable features and their combination are discussed. The present study will provide a framework for future applications comprising the characterisation of real defects and stress profiles in engineering components.

Keywords:

• pulsed eddy current
• feature extraction
• feature optimisation
• principal component analysis (PCA)
• curvature

Acknowledgements

The authors would like to thank the China Scholarship Council to fund Mr. Deqiang Zhou undertaking visit study at Newcastle University.