回转类锻件视觉测量系统自标定

Self-calibration of Single Camera System Used in Cylinder-shaped Forging Parts Measurement

针对回转类锻件视觉测量系统标定问题,本文提出了一种基于被测对象自约束特征的系统参数自标定方法。首先,利用筒类锻件和支撑轴的回转特性,通过共轴截面曲线圆环点和极线约束建立摄像机系统内参数约束方程,求解测量系统所有内部参数。其次,在求得的内参数矩阵的基础上,通过锻件回转轴和截面图像的成像特点建立测量系统外参数方程,求解测量系统外部参数。实验结果表明,该方法只需利用被测对象自身几何约束,不需任何标定板和标定块,标定过程简单有效。

Aiming at the difficulty of single camera system calibration used in cylinder-shaped large forging parts measurement, a new self-calibration method was proposed based on self constraint of the target cylindershaped object; the inner and outer parameters of the measurement system were achieved from a single image. Firstly, taking advantage of the rotation characteristics of the cylinder-shaped large forging parts and the supporting shaft, inner parameter constraint equations were established based on circular points and epipolar constraint derived from images of cross sections. And then the full inner matrix of the measurement system was solved using the constraint equations. Secondly, the outer parameter equations were established using the image of rotation axis and cross sections as well as the inner parameters, and the outer parameters were achieved. Experimental results verified the convenience and effectiveness of the proposed method