Development on Three-dimensionally Traveling SQUID System for Nondestructive Evaluation

Abstract

A practical robotic three-dimensional (3D) SQUID-NDE system was developed for the first time. This system is based on a previously developed traveling SQUID-NDE (i.e., one that is not stationary, but the SQUID sensor itself moves or scans along the surface of the object), which incorporates SQUID sensor travel technologies such as the `pseudo' third-order SQUID gradiometer. The system developed is composed of a traveling SQUID gradiometer, an articulated-type robot used as a SQUID sensor manipulator, a laser CCD displacement sensor, and a numerical interpolation procedure to reconstruct the surface of the evaluated object without the need for CAD data. To demonstrate the capability of this imaging system, it was used to detect artificial damage in a stainless steel (type-304) tube. The system successfully detected the artificial damage. It is anticipated that the robotic 3D SQUID-NDE imaging system will be in practical use in the near future.