3D vision inspection for internal surface based on circle structured light

3D vision inspection plays an important role in industry environment. This paper focus on 3D vision inspection for internal surface based on circle structured light. The inspection system, established in this paper, consists of an Olympus industrial endoscope, a digital CCD camera, a single-circle pattern laser, a conic reflector, a transparent thin glass tube with the outer diameter of Ø4.2 mm, a motorized linear motion stage, a personal computer and a few accessorial brackets. The inspection system is calibrated by a two electronic theodolites system and a plane target efficiently. Based on the mathematic model of the inspection system, the 3D shape of the internal surface is obtained from the 2D structured light stripe image on the internal surface. The experimental results show that the inspection system has a calibration accuracy of RMSx = 0.032 mm, RMSy = 0.011 mm, and RMSz = 0.029 mm, and a measurement accuracy of RMSx = 0.041 mm, RMSy = 0.019 mm and RMSz = 0.038 mm. It is proved that the inspection system is applicable to inspecting internal surface with high efficiency and accuracy.