In this study, a MFL (Magnetic Flux Leakage) image based 3D inspection system which is incorporated into a cable climbing robot was investigated for Steel Cable NDT of Cable-stayed Bridge and Suspension Bridge. Firstly, a MFL sensor head prototype composed of two permanent magnets and eight hall sensors was designed and fabricated. A steel cable specimen with several types of damage was inflicted and scanned by the MFL sensor head to measure the magnetic flux density of the specimen. The measured MFL signals were used to interpret the healthy condition of the steel cable. For improving the resolution and quantification of the damage level, digital signal processing techniques were performed. Finally, the measured MFL signals were visualized by using 3D imaging method.

• 박승희(성균관대학교 사회환경시스템공학과 교수, 공학박사) | Seunghee Park
• 김주원(성균관대학교 u-City 공학과 박사과정) | Ju-Won Kim
• 이종재(세종대학교 토목환경공학과 교수, 공학박사) | Jongjae Lee
• 길흥배(한국도로공사 도로교통연구원 수석연구원, 공학박사) | Heungbae Gil