A Classification Algorithm for Anomaly Detection in Terahertz Tomography

Abstract

Terahertz tomography represents an emerging field in the area of nondestructive testing. Detecting outliers in measurements that are caused by defects is the main challenge in inline process monitoring. An efficient inline control enables to intervene directly during the manufacturing process and, consequently, to reduce product discard. We focus on plastics and ceramics and propose a density-based technique to automatically detect anomalies in the measured data of the radiation. The algorithm relies on a classification method based on machine learning. For a verification, supervised data are generated by a measuring system that approximates an inline process. The experimental results show that the use of terahertz radiation, combined with the classification algorithm, has great potential for a real inline manufacturing process.