为了实现大尺寸空间异面直线夹角检测系统的现场标定,提出了基于待测对象的现场标定方法。结合一个具体的工程实例介绍了系统的测量方法,针对系统内部机器视觉子模块的测量对象提出了适于现场快速实施的标定策略。分析了影响系统检测精度的各项误差源,给出了系统标定板的设计加工方案。研究了系统的框架设计和标定板布局的合理性。设计了标定环节的数字图像处理流程,并给出了各个步骤的处理结果。实验结果表明,在光照条件为355lx的情况下,采用所提出的标定方法使视觉检测系统的误差均值由0.065123°缩减为0.00219°,补偿效果满足要求,系统对于间隔7m的异面角度的标准测量不确定度为0.114°。
In order to achieve the in-situ calibration of the measurement system for angle between bifacial lines in large-scale space,the calibration approach based on target is proposed.A practical engineering project is taken to introduce the measuring principle,and in-situ calibration strategy which is suitable for quick implementation is presented.The error sources of measurement system are analyzed and the design proposal of system calibration board is proposed.The reasonableness of framework design and layout of calibration board is checked.The digital image processing algorithm of calibration is designed,and the result of each step is proposed.Experiments indicate that the mean error of the visual inspection system is reduced from 0.065123° to 0.00219° using the calibration method with the illumination condition of 355 lx.The effect of error compensation meets the requirement,and the standard uncertainty of measurement for the angle of bifacial lines separated at a distance of 7 m is 0.114°.