空间圆几何参数的非接触高精度测量方法

High Accurate Non-contact Method for Measuring Geometric Parameters of Spatial Circle

分析了空间圆透视投影的数学模型 ,并建立了点的空间三坐标立体视觉测量数学模型。提出了一种基于立体视觉的空间圆几何参数的非接触测量方法 ,根据极线约束求出空间圆在双目立体视觉中的对应匹配点 ,后投影到三维空间求出边缘的实际坐标 ,采用基于空间三维圆最优拟合求取空间圆的几何中心的三维空间坐标和圆半径等几何参数。该方法减小了空间圆透视投影形状畸变引起的测量误差 。

The perspective projection model of the spatial circle is discussed and the mathematical model of three-dimensional (3D) measurement for the stereo vision sensor is analyzed. One feasible vision inspection solution to measure the dimensions of the circle and the 3D coordinates of its center is proposed. Based on the epipolar constraint, the correspondence edge points of space circle are obtained and the coordinates of the circle edge in the 3D space are measured by the binocular stereo vision inspection, then the dimensional parameters of the circle in 3D space can be obtained by using 3D circle fitting with the circle edge. The proposed approach can eliminate the perspective projection shape distorted of the circle features in the image plane, so it improves the measuring accuracy of the circle with the binocular stereo vision inspection method.