Machine Learning Techniques for the Analysis of Magnetic Flux Leakage Images in Pipeline Inspection

IEEE Transactions on Magnetics, 2009.
Ahmad Khodayari-Rostamabad, J.P. Reilly, N.K. Nikolova1,
J.R. Hare, and Sabir Pasha

Abstract   The magnetic flux leakage (MFL) technique is commonly used for non-destructive testing of oil and gas pipelines. This testing involves the detection of defects and anomalies in the pipe wall, and the evaluation of the severity of these defects. The difficulty with the MFL method is the extent and complexity of the analysis of the MFL images. In this paper we show how modern machine learning techniques can be used to considerable advantage in this respect. We apply the methods of support vector regression, kernelization techniques, principal component analysis, partial least squares, and methods for reducing the dimensionality of the feature space. We demonstrate the adequacy of the performance of these methods using real MFL data collected from pipelines, with regard to the performance of both the detection of defects, and the accuracy in the estimation of the severity of the defects. We also show how low–dimensional latent variable structures can be effective for visualizing the clustering behaviour of the classifier.