Measurement model of the omnidirectional structured-light vision and its calibration method

The omnidirectional structured-light vision measurement is significant for inner surface inspections. In existing systems, the camera and the projector are installed inside a glass tube, inevitably causing the refraction distortion. In this paper, we propose a measurement model of the omnidirectional structured-light vision and the corresponding calibration method. The model can correct the refraction distortion and realize the omnidirectional measurement. An aluminum tube with an internal diameter of 288.50 mm is measured by the system. The repeatability and precision reach 0.05 mm and 0.23 mm, respectively. The experimental results prove that the accuracy is improved by 7.9 times compared with the model ignoring distortion.