基于点阵编码的三维主动视觉标定

提出一种基于位错点阵编码三维成像系统的标定方法.首先在物空间建立三维数据基准,然后通过基准传递的概念标定摄像子系统,再通过建立摄像子系统坐标系与投影子系统坐标系之间的约束关系,将标定后的摄像子系统的准确度传递到投影子系统坐标系.摄像子系统坐标系与投影子系统都具有标定的准确度之后,可以根据位错点阵编码三维成像技术的解码算法获得深度图像空间坐标的计算值,然后将其与物体空间的三维标定数据基准进行比较,建立目标函数为误差平方和最小的非线性优化方程.通过迭代求解这个优化方程,最终获得三维系统的结构参量.实验结果表明,经过三维标定的位错点阵编码三维成像系统,对300×300×80 mm3的测量体积内,可以获得X方向的标准差为0.29mm和Y方向的标准差为0.24mm,Z方向的标准差为0.29mm的测量准确度.

Calibration method for 3-D vision system using point array encoding

An approach of calibration method for three-dimensional (3-D) vision system based on shifted point array encoding was presented in this paper.Initially a 3-D calibration benchmark was established in object space,thus the camera subsystem can be calibrated with the benchmark in light of the concept of benchmark transmission.Furthermore the projection subsystem could be calibrated according to the constraint condition between the camera and the projection subsystems.Once both subsystems have been calibrated,in light of the shifted point-array encoding method the 3-D coordinates of range image could be obtained with moderate accuracy,which could be used to compare with the prescribed benchmark in order to build up a square-error based objective function,leading to a non-linear equation.By solving this equation,all structural parameters involved in 3-D vision system could be determined with appropriate accuracies.Experiment results showed that,after proposed calibration procedure,the 3-D vision system based on point array encoding was able to achieve such accuracy as the standard deviation in X direction is 0.29 mm, 0.24 mm in Y direction,and 0.29 mm in Z direction,respectively,for a measuring volume of 300×300×80 mm3.