摘要
基于交比不变性原理和一维靶标点共线的特点,提出了一种多视觉传感器全局校准方法。以一个视觉传感器坐标系为基础建立全局坐标系,称该视觉传感器为基础视觉传感器。将一维靶标在基础视觉传感器和待校准视觉传感器前合适位置摆放至少两次,根据拍摄得到的3个或3个以上的靶标点图像坐标,由交比不变性原理,对每个视觉传感器求解不在视场区域的靶标点图像坐标。结合靶标点之间的距离约束,求解待校准视觉传感器到基础视觉传感器的转换矩阵。根据一维靶标特征点共线的特点,通过捆绑调整方式得到转换矩阵的最优解。最后,通过两两视觉传感器校准的方式完成多视觉传感器全局校准。该方法不需外部辅助设备,简单灵活,实用性强,全局校准精度可达0.041 mm。
Based on the invariance of cross-ratio and the collinear property of all points for one dimensional target, a global calibration method of multi-vision sensor system is proposed. The global coordinate frame is constructed based on the coordinate frame of one of the vision sensors, which is called the base vision sensor. The one dimensional target is positioned arbitrarily for at least twice in front of both the base sensor and the sensor to be calibrated. For each vision sensor, the image coordinates of the target feature points out of the view field are computed utilizing the image coordinates of at least three feature points captured by the vision sensor according to the invariance of cross-ratio. A trans- formation matrix from the coordinate frame of the sensors to be calibrated to that of the base sensor is solved by considering the distance restraint between target points and optimized solution is obtained by non-linear optimization method. The global calibration of multi-vision sensor system is realized by pair-wise calibration between the base vision sensor and each of the vision sensors to be calibrated. Experiment results show that proposed method can do calibration without any high-accuracy 3D measuring equipment,it is simple, flexible and applicable in various situations. Calibration result shows that the error of global calibration method is 0.041 mm.
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2008年第11期2274-2280,共7页
Optics and Precision Engineering
基金
国家自然科学基金资助项目(No.50727502)
关键词
全局校准
一维靶标
多视觉传感器
交比不变性
global calibration
one dimensional target
multi-vision sensor
invariance of cross-ratio
