SOC 시설물 균열인식을 위한 영상분석 파라미터 연구

초록

Cracks are caused by physical factors on concrete structures. Therefore regular crack inspection is important to ensure safety of concrete structure. To substitute visual inspection by inspector with image-based inspection system, the crack extraction algorithms has been developed. However, the effect of illuminance, brightness and measurement distance has to be considered to use the automatic crack inspection system in the field. In this paper, we have studied the effect of illumination, object distance, brightness of crack on crack recognition. To find out the effect, we carry out two experiments after attaching simulated cracks those describe various brightness and width on the concrete tunnel. First, to find out the effect of distance between crack and camera, we have taken photographs at difference distances and analysis the images. Second, to find out the effect of illumination, we have taken photographs when illumination is 9 lx, 90 lx, 960 lx, 10,700 lx. The results of experiment show that minimum recognizable crack width is increased with increase of distance and decrease of illuminance. At 5 m and 60 m, 5 mm and 30 mm of crack width are able to be recognized. And at 45m of distance, when illumination is 10,700 lx and 9 lx, recognizable crack width is 15 mm and 30 mm. The result can be used as a reference when apply image detect system to the field.