유리섬유 복합재료 내부 결함 검사를 위한 갈바노 스캐너 기반의 고속 테라헤르츠파 검사 시스템 개발

초록

A high-speed terahertz (THz) wave inspection system based on a galvano scanner was developed to inspect the defects in glass-fiber-reinforced polymer (GFRP). To overcome the speed limitation of the stage scanning method, the stage was replaced with a galvano scanner, which is less influenced by inertia and backlash. The high-speed THz wave inspection system was manufactured by combining a continuous (CW) THz wave system, a galvano scanner, and an aspherical telecentric f-theta lens. The high-speed THz wave inspection system was controlled by interfacing the galvano scanner and the CW THz wave system. The imaging performance of the combined system was evaluated by scanning a plate with a hole, and the focus of the THz signal was corrected through laser alignment of the system. Scanning for defects in the GFRP was then performed with the high-speed THz wave inspection system, and the imaging result was compared with that obtained using a conventional stage scanning method. Consequently, defects inside the GFRP could be inspected a factor of 11 faster than using the stage scanning method with over 90% probability of detection through the developed high-speed THz wave inspection system.

키워드