光笔式单目视觉测量系统的关键技术

Abstract

In order to achieve the high-precision,large-size,three-dimensional space and real-time measurement of mechanical components,a monocular vision measurement system with a light pen was established. The new technology,algorithm converting model,the optimization of camera focal length and the position calibration of the light pen probe were studied. First,a new type of light pen which was designed by using the photolithography process was proposed. Then,based on resection principle of single image space in the close-range photogrammetry,the new conversion relationship between the light pen coordinate system and the camera coordinate system was established. Optimal exterior orientation elements of single image space was solved by least squares adjustment method in the loop iteration,and basic parameters of the transformation model were determined. Finally,the impacts of focal length on the result of monocular vision measurement system were analyzed,and a method to determine the relatively accurate focus length and the position of light pen probe in the coordinate system of the light pen was proposed. Experimental results indicate that the stability errors in the xaxis,y-axis,z-axis directions of the camera coordinate system are 0. 042 733 mm,0. 048 513 mm and0. 066 39 mm,respectively,and the maximum measuring error is 0. 173 mm. These results meet the requirements of monocular vision measurement system with a light pen for stability and high accuracy.