The Design Of Large-Scale Vision Tracking Coordinates Measuring System

With the rapid development of science and technology, large-scale high-precision online 3D measurement technology is demanded more and more urgently in the fields of avigation, spaceflight and civil industry. The traditional coordinate measurement technology can not meet the above-mentioned requirement, so a new coordinate measurement technology is needed to resolve the problem. And that the vision coordinates measurement technology is a rising 3D spatial coordinate measurement technology based on computer vision technology and coordinate measurement technology, it fits to modern production which needs measurement technology that holds higher measurement precision and larger measurement scale from a bran-new coordinates measurement idea.In the paper, an optical probe imaging vision tracking coordinate measuring system using a single camera is proposed. In this system a rotator is adopted and the axis of the camera always aims at the moving optical probe to ensure the probe imaging in the center of the image plane. By vision tracking, the measuring range of the system is extended. Firstly, the structure of the vision tracking coordinate measuring system and its measuring principle is presented. A nonlinear measurement and tracking mathematical model of the system is set by perspective transform and optical imaging principle. A method of Newton nonlinear iteration to resolve the tracking equation is described. The experiments show that the model and the resolving method are correct. Secondly, theory of space transform related is introduced, and an algorithm of used to calibrate the parameters of the system is given. Thirdly, the drive software and control strategy of the rotator servo system is analyzed. In the end, the vision tracking system is constructed, and a tracking experiment is done. The results of tracking experiment show that the system can meet the requirements of vision tracking. The standard deviation of the coordinate results is smaller than 0.40mm, and the system can be used in the situation that the precision request is not strict.