基于Tsai两步法的视觉点胶系统相机标定方法

摘要

Camera calibration is an important step in machine vision systems applied to the practical industry.Due to the fact that most of the traditional methods need calibration board and the production of that and the placement process are relatively complicated,we propose an improved simple calibration method based on Tsai's two-step cali bration method in this paper.Using this method,we extract feature points with match method while the platform moving rather than using calibration board,which makes the process more convenient and practical.The camera model takes the first-order radial distortion into consideration and requires only linear calculation to avoid the cumbersomeness of nonlinear calculations.Experimental tests show that the proposed method can effectively reduce the complexity of calibration,reduce calibration time,and achieve an accuracy of ±0.1 mm,which meets the engineering application requirements of visual dispensing systems.%相机标定是机器视觉系统应用的一项重要步骤.针对传统标定方法大多使用标定板、而标定板的制作和摆放较为繁杂的问题,提出一种基于Tsai两步法的简易标定方法.提出的方法不需要使用标定板,只需通过平台运动拍摄图标、提取特征点,操作简单,同时该方法通过合理的求解步骤,使用线性计算,避免了非线性计算的复杂过程.实验测试表明所提方法能有效降低标定复杂程度,减少标定时间,精度可达±0.1mm,满足了视觉点胶系统的工程应用要求.