基于双重虚拟圆靶标的激光扫描测头标定  

Calibrating Laser Scanning Probe with Double Virtual Circle Target

作　　者：陆敏恂[1] 葛卫梁 周爱国[1] 吕刚[2] 周飞[1] 

机构地区：[1]同济大学机械与能源工程学院,上海201804 [2]海克斯康测量技术(青岛)有限公司,山东青岛266101

出　　处：《光学学报》2014年第10期197-203,共7页Acta Optica Sinica

摘　　要：提出了一种基于双重虚拟圆来标定光平面的新方法。该方法利用棋盘的角点在图像坐标系下构建双重虚拟圆,虚拟圆与激光光条直线建立了相对的位置关系,根据交比不变原理计算出光条上的特征点在摄像机坐标系下的坐标。在摄像机视场范围内多次变换棋盘位置,构造出的虚拟圆也相应变换,由此计算得到更多的特征点,利用最小二乘法拟合光平面方程。实验表明,该方法求得的精度要明显优于实际的圆形靶标标定的精度,光平面标定的均方根误差为0.04mm,且棋盘靶标更易于制作,标定计算简单可靠,适合现场标定。A new calibration method for laser plane with double virtual circles is put forward. This method creates double virtual circles in the image coordinate using the corners of chessboard. Position relationship is established between the virtual circles and the laser stripes. The feature point coordinates of the laser stripe in the camera coordinate system are calculated according to the principle of cross-ratio invariance. The chessboard position is changed for several times within the field of the camera vision aiming to calculate more feature points. All these feature points are fitted to an ideal plane by the least square method （LSM）. The experimental results indicate that the precision is obviously higher than the actual circle target. The root mean square （RMS） error of the laser plane calibration is 0.04 mm and the target is easier to make. It concludes that the calibration process is simple, reliable and suits for calibration on spot.

关 键 词：机器视觉 光平面标定 双重虚拟圆 交比不变 棋盘角点 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]