核反应堆容器检测平台精确定位方法

Method of precise positioning for nuclear reactor container inspection platform

针对现阶段核反应堆容器检测平台无法实现全自动定位、定位精度低等问题,文中提出一种基于机器视觉的精确定位方法。首先结合定位特征、测量环境及定位需求设计精确定位分系统,并对定位分系统的布局进行优化调整;其次利用空间圆拟合与SVD实现探头轴线的标定和检测平台全局坐标系的统一;然后通过图像筛选与特征拟合,采用平面切割法实现贯穿件轴线的测量,在此基础上计算出探头轴线的对中偏差值,并转化到运载小车坐标系下,驱动小车进行精确定位;最后在模拟检测现场对该方法的定位性能进行实验验证。结果表明,精确定位分系统的定位误差可控制在2.6 mm以内,说明文中的设计方法可提高检测平台的定位效率,满足检测现场的定位要求。

As the existing nuclear reactor container inspection platform cannot achieve automatic positioning and has low positioning accuracy,a precise positioning method based on machine vision is proposed.A precise positioning subsystem is designed by combing the positioning characteristics,measurement environment and positioning requirements,and the layout of the positioning subsystem is optimized and adjusted.The spatial circle fitting and SVD are used to realize the calibration of the probe axis and the unification of the global coordinate system of the detection platform.After the image screening and feature fitting,the axis of the penetration assembly is measured by means of the plane cutting method.On this basis,the alignment deviation value of the probe axis is calculated and transformed into the coordinate system of the carrier car to drive the car for the precise positioning.The positioning performance of this method was verified by the experiments in the simulated detection field.The results show that the positioning error of the precise positioning subsystem can be controlled within 2.6 mm.The design method can improve the positioning efficiency of the detection platform and meet the positioning requirements of the detection site.