열화상 영상을 이용한 하수관 결함조사시스템 개발

It takes very long to measure a crack with the use of a CCTV robot for inspecting sewer defects. That is because it is required to remove many impurities deposited in a pipe in order to put and move a CCTV robot in the sewer pipe. The sewer defect inspection system developed to save such temporal and financial costs is designed to go to the middle part of a sewer pipe and make inspection and measurement with the uses of thermal images and CCTV. For performance test and evaluation, a 600 mm concrete pipe and a 300mm PVC pipe were buried 15m, respectively. As a result, it was possible to clearly find very small cracks, which are hard to be detected with the naked eye in CCTV, through thermal imaging, and to quantitatively analyze a crack area with the crack area calculation program using the developed thermal imaging data. The performance of the sewer defect inspection system developed in this study can be classified into three types as follows. First, by checking cracks through thermal detection and CCTV and using the crack area calculation program developed in this study, it was possible to find a crack area quantitatively. Secondly, through quantitative defect inspection, it was possible to select a proper repair construction method depending on a type of defects, a size, and a position, and thereby to remarkably reduce uncertain factors which can arise under an engineer''s judgment only. Finally, there was cost saving in the defect inspection. In other words, by using the pipe wall in the middle part of a sewer pipe, not in its bottom, it was possible to inspect defects regardless of impurities and thereby to considerably save the cost for removing impurities.