摘要
准确地标定系统参数是利用线结构光进行高精度测量的前提,提出了一种基于平面标靶的线结构光参数标定算法,以期达到在工业现场进行高精度标定的目的。系统标定时,需要将激光线投射到平面标靶上,并在不同位置拍摄带有激光线的标靶图像。首先,计算相机内参数;然后,通过内参数确定标靶平面在相机坐标系下的方程,并由此计算出激光点在相机坐标系下的三维坐标;最后,通过线性最小二乘方法拟合得到光平面方程。相对于交比不变方法,本文算法可以获得更加稠密、准确的标定点。在一种结构光扫描系统中的应用结果表明,本文算法均实可行,光平面标定平均误差为0.024mm,系统扫描平均误差为0.035mm。
High accuracy calibration is the precondition of the measurement by line structured light. To achieve the above purpose, this paper presents a calibration algorithm for line structured light based on planner target. Firstly,laser line is projected to the target and images are taken at different positions. Then,camera intrinsic parameters are computed and the target plan function under camera coordinate system is got. Based on the plan function, laser point positions under camera coordinate are reconstruc- ted. With more than two images taken from different positions, the laser plan function can be calculated by using the linear least square error method. Compared with methods based on invariance of cross ratio, the proposed laser plane calibration algorithm can get much more and more accurate calibration points. The algorithm＇s availability is assessed by its application to a line structured light scanning system. Experimental results show that the mean calibration error by the proposed algorithm is less than 0. 024 mm and the scanning error is 0. 035 mm.
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
2013年第8期1557-1562,共6页
Journal of Optoelectronics·Laser
基金
国家自然科学基金(51109021)
中央高校基本科研业务费(2012QN022)资助项目
关键词
测量
线结构光
标定
视觉检测
measurement
line structured light
calibration
vision inspection
