Non-Contact 3D Coordinates Measurement of Cross-Cutting Feature Points on the Surface of Large-Scale Workpiece Based on Machine Vision Method

3D coordinates measurement of feature points on the surface of large-scale workpiece is important and difficult, various relative measuring methods have been presented in recent years, and machine vision method has been paid more attentions by researchers. The application of machine vision method in the 3D coordinate measurement of feature points on the surface of large-scale workpiece is discussed in this paper, and an accurate, simple, new measuring method is proposed. The design of the measuring system mainly consider the following aspects: the principle and composition of the measuring system; the study on the monocular vision for the camera locating; the calibration method of CCD camera; image processing of cross-cutting feature point and the calculation of its 2D image coordinates; the study of binocular stereo vision based on the large-scale CMM. The experimental results indicate the correctness and reliability of the new measuring method and show that it can be used in the noncontact 3D coordinates measurement of cross-cutting feature points on the surface of large-scale workpiece