A void shape detecting sensor for pipeline inspection

This paper presents the concept and design of a strain gauge sensor, which is a part of a pipe crawling robot and can be used for the purpose of detecting the shape of a collapsed pipe or tunnels like voids within rubble. The paper illustrates the sensor's working principle. The sensor uses a spline interpolation algorithm combined with a looking‐up table method to estimate the void shape. The paper also presents the software interface and the laboratory experiment of the sensor. Discussions about the experimental results are given in the later part of the paper.