Automated extraction of buried pipes from 3D ultrasonic images by fuzzy inference

Non-destructive testing (NDT) using ultrasonic wave rapidly advances with the development of hardware. The NDT of concrete using ultrasonic waves is the most promising approach to find the crack depth and internal flaw of the concrete. It is required in NDT research to find buried pipes such as steel pipes and resin tubes. However, there is no work on finding such pipes by an ultrasonic system. The variety of formation from concrete to concrete prevents finding them. We propose a novel method to extract the buried pipes aided by fuzzy logic. First, we show a method to remove the direct wave from the raw data. It can find the signals of the pipes. Second, buried pipes can be extracted by fuzzy inference based on the signal value and voxel number.