A Feasibility Study on Guided Wave- Based Robotic Mapping

Ultrasonic guided wave imaging techniques have received much attention in recent years for fast screening of large structures. Here we explore the feasibility of Occupancy Grid Mapping (OGM) in order to construct a map of an unknown component for inspection. OGM is a well-established algorithm in robotics, but for the first time we are applying it to Shear Horizontal (SH) guided wave imaging. This approach, in contrast to some existing guided wave-based imaging techniques, would not require prior knowledge of an intact state of the sample. OGM works on the ranges obtained by the Time of Flight (ToF) of the received signals operating in pseudo-pulse-echo mode.

I. Introduction

Manual NDE inspection can be slow, expensive and potentially hazardous to an operator, such as when performing NDE inspection of high-radiation areas of nuclear power stations. In contrast, automated inspection can be cheaper, safer and more accurate [1]. However, the state of the art robotic inspection scans maximise coverage across the component surface using conventional ultrasonic transducers (including wheel probes), limiting their application for automated in-service inspection.