视觉测量系统的相机校准(英文)

Camera calibration technique for vision measurement system

提出了一种利用虚拟立体校准模板的有效相机校准技术。通过红外发光二极管按照预定路径在三坐标测量机上移动,构成精确的虚拟立体校准模板。校准过程中考虑了径向畸变和切向畸变。采用二次高斯曲面拟合,精确地提取像点的质心坐标。校准过程包括线性参数估计和基于最大似然估计的非线性校正。首先采用线性方法对部分参数进行初始估计,然后再通过基于最大似然估计的非线性最小化获得所有的参数值。该方法可精确获取图像点坐标和空间点坐标,能够实现快速、有效收敛。实验结果表明,该校准技术能够满足视觉测量系统的要求,也可以满足视觉测量系统对相机参数的特殊要求。

This paper presents a high-precision camera calibration technique, which uses a virtual stereocalibration pattern formed by an infrared light-emitting diode （IR LED） moving along the pre-defined path on CMM. It takes into account both radial and decentering distortions and uses Gaussian distribution fitting to accurately obtain the imaging centers of feature point image coordinates. Following the maximum likelihood criterion and initial parameters are linearly computed, and final values are obtained through nonlinear minimization based on the maximum likelihood criterion. Within accurate image and space coordinates, this method can rapidly converge. Experimental results show the proposed method can satisfy the requirements for camera calibration of a vision measurement system.