中国激光, 2014, 41 (11): 1108002, 网络出版: 2014-09-18
基于量块的线结构光视觉传感器直接标定方法
Direct Calibration Method of Laser Stripe Vision Sensor Based on Gauge Block
摘要
线结构光视觉传感器的标定精度直接关系到测量结果的精度。传统的有模型标定方法为了提高标定精度,相应的模型也会越复杂,计算量也很大。为了实现高精度、高效率、低成本地标定线结构光视觉传感器,提出一种基于标准量块的线结构光视觉传感器直接标定方法,设计了标定靶标,不需要标定模型,直接建立查找索引表,在查找索引表中搜索直接得到或者采用最小二乘法拟合算法得到待标定点的空间三维坐标。实验结果表明该标定方法具有较高的标定精度,y方向平均绝对测量误差为0.0279 mm,z方向平均绝对测量误差为0.0237 mm,能够满足高精度测量需要,且计算简单、易于实现。
Abstract
The calibration accuracy of laser stripe vision sensor is directly related to accuracy in measurement. The commonly adopted calibration method is model-based calibration method. The model will become significantly complicated and the calculation will become complex when a high measurement accuracy is required. In order to calibrate the laser stripe vision sensor with high accuracy, high efficiency and low cost, a direct calibration method for laser stripe sensor based on gauge block which does not require model is proposed. Firstly, a calibration target is designed. Secondly, a lookup table of the direct mapping relationship between image coordinates and three-dimensional coordinates of feature points is built. Finally, three-dimensional coordinates of an arbitrary point can be obtained from the lookup table directly or with least-square fitting algorithm. Experimental results demonstrate that this direct calibration method has high accuracy. Its average absolute measuring accuracy is 0.0279 mm in y direction and 0.0237 mm in z direction. It concludes that this method can meet the requirements of high accuracy measurement, and the calculation is simple and easy to implement.
邹媛媛, 赵明扬, 张雷. 基于量块的线结构光视觉传感器直接标定方法[J]. 中国激光, 2014, 41(11): 1108002. Zou Yuanyuan, Zhao Mingyang, Zhang Lei. Direct Calibration Method of Laser Stripe Vision Sensor Based on Gauge Block[J]. Chinese Journal of Lasers, 2014, 41(11): 1108002.