Robotic system for inspection of test objects with unknown geometry using NDT methods

Abstract

The aim of this work is to develop a portable Non-Destructive Testing (NDT) robotic system that can be carried by CLA WAR to evaluate defects in geometrically complex surfaces and industrial products. In this paper, the difference in quality of defect dataduring manual inspection and automated inspection will be compared. Tests have been performed amongst others on complex shaped turbine blades using eddy currents. The challenge is to be able to follow the surface by keeping the NDT probe normal to the surface while maintaining a constant contact force with it. The approach to maintaining a constant contact force and angle to the object was to use a secure contact using permanent magnets and a force adapting control of the manipulator which resulted in improvements inthe quality of inspection compared to manual inspection. Furthermore, a novel application of the position-force-moment (PFM) control was developed. Here, the robotic arm scans unknown contoured surfaces by keeping the sensor probe normal to the test surface, maintaining at the same time constant contact force, thereby ensuring good data acquisition. Copyright © 2008 by World Scientific Publishing Co. Pte. Ltd