| In today’s world, scientific technologies are undergoing rapid changes. The researches engaged in by people on aviation, aerospace, military and civilian fields are becoming more and more precision and intelligent. As the traditional coordinate measurement technology has been unable to meet the above requirements, it needs new measuring methods and technologies to solve the problem. In addition, due to the wide application and rapid development of computers, the 3D-vision coordinate measurement technology, which is a new way based on photogrammetric principle and computer technology, has made great progress recently. It adapts the new and higher requirements of modern technology in the measurement accuracy of measurement, measuring range and other aspects.This paper studies the current domestic and international vision measurement on the latest developments, and for the practical application, a binocular vision coordinate measurement methods based on optical imaging of feature points of the probe is put forward. In this method, the double CCD digital cameras within the parameters through the accurate calibration placed in the measurement site gets the image of the optical probe feature points, through the analysis of the coordinates of feature points and the known optical measuring stick, space coordinates of points are determined by the measured geometric constraints knowledge to achieve the purpose of measurement.In the coordinate measurement system, the relative position and orientation of two cameras are accurately calibrated by an optical bar. By moving an optical bar in a pattern in and around the measurement volume, the optical feature points on the bar are imaged by the two cameras and form matching points. The relative position of the two cameras, about a scale factor, are determined from epipolar constraint. Then, the calibrated distances of the feature points on optical bar are used to calculate the scale factor according to scale constraint between the feature points and their back projective points. So, the true relative position and orientation of the two cameras can be accurately determined.In the modeling of the measurement of system, we consider fully the system error caused by the various structural parameters. On the basis of the analysis,we adjust the measured system’s layout, which minimizes the system error caused by the external environment. Finally, the overall measurement system test trials to test the system’s measurement repeatability of single point and the standard gauge block measurement uncertainty and other technical indicators. |
