Study on In-Pipe Corrosion Diagnosis System -Corrosion Estimation Using Wavelet Transform and Two-dimensional Information-
Shintaro Sakamoto*, Toshio Fukuda**, Hironori Yui**,
Yasunori Abe*****, Yasuhisa Hasegawa***,
Futoshi Kobayashi****, and Fumihito Arai**
*Research and Development Center, Shinryo Corporation, 41 Wadai, Tsukuba, Ibaraki 300-4247, Japan
**Department of Micro System Engineering, Nagoya University, 1 Furo-cho, Chikusa-ku, Nagoya-shi, Aichi 464-8603, Japan
***Department of Mechanical Systems Engineering, Faculty of Engineering, Gifu University, 1-1, Yanagido, Gifu 501-1193, Japan
****Department of Machine and System Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe-shi, Hyogo 657-8501, Japan
*****ForU Corporation Limited, 23/F., The Toy House100 Canton Road, Tsimshatsui, Kowloon, Hong Kong
In line with changes in societal expectations, demand is increasing for building equipment inspection and diagnosis. The diagnosis of air-conditioning pipes is an important safeguard against unexpected problems such as pipe leakage. Estimating the shape of corrosion is very effective in determining its cause. We developed a method for estimating the shape of artificial corrosion, but could not apply it to natural corrosion because of the complex shape. We believed that it could be applied if pipe thickness was measured accurately. In this paper, we describe the method used to measure precise thickness, to detect individual echoes from overlapping data using wavelet transforms, and to select the echo at measuring points using data from surrounding points. We show the results of experiments in which we applied the method to natural corrosion in pipes.
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