Feature detection and monitoring of eddy current imaging data by means of wavelet based singularity analysis

The objective of the paper is to apply a wavelet based singularity method to detect and monitor transient activity in the eddy current data, which is of particular interest for industrial use in order to check signal levels. The paper begins with a description of the fundamentals of methodologies for singularity measurement including calculation of Lipschitz indexes and selection of effective wavelets suitable for the applications. An electromagnetic induction system from which eddy current data are obtained is briefly described for this case study. Applications of this method to eddy current imaging data are therefore explored. The paper demonstrates that the wavelet based singularity method can be effectively employed in identifying transient features in the electromagnetic data and locating the signal changes to determine the time period of the transients. Turbulent features in the signals due to the dedicated movement of metal flow can also be identified. © 2010 Elsevier Ltd. All rights reserved.