通用机器人视觉检测系统的全局校准技术  

Global calibration of visual inspection system based on universal robots

作　　者：王一[1] 刘常杰[1] 任永杰[1] 叶声华[1] 

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072

出　　处：《光学精密工程》2009年第12期3028-3033,共6页Optics and Precision Engineering

基　　金：国家863高技术研究发展计划资助项目(No.2008AA042407);国家自然科学基金资助项目(No.50805105)

摘　　要：介绍了基于通用机器人的车身在线柔性视觉检测系统的工作原理和在复杂现场环境下使用激光跟踪仪和测量臂进行全局校准的实用方法。基于测量姿态的全局校准方法,利用机械约束将传感器坐标系和靶标坐标系统一起来,实现测量姿态时传感器坐标系与系统基准坐标系的坐标转换。基于机器人运动学模型的全局校准方法,利用机器人末端关节位姿可通过正向运动学获知的特点,在现场构建机器人基坐标系,并通过坐标变换获得与机器人运动精度无关的手眼关系,实现任意姿态时的全局校准。实际测量结果表明,应用两种校准方法后系统的重复性精度都十分理想,测量装置重复测量标准差和系统重复测量标准差分别为0.07mm和0.13mm,能够满足在线监控白车身加工尺寸变化的精度要求,系统进行坐标测量时的误差分别为±0.2mm和±0.8mm。An on-line and flexible visual inspection system based on universal robots was introduced for the car body-in white （BIW） and two practical global calibration methods by using a laser tracker and a measuring arm were described in complexity field environments. The method based on a measuring posture realized the coordinate transformation between the sensor coordinates and the system reference coordinate by combining the sensor coordinates with the target coordinates through the mechanical constraint. And the method based on the robot kinematics realized the global calibration at arbitrary postures by establishing a robot coordinate frame in fields and by obtaining hand-eye calibration rela- tion through the coordiate transformation. Experimental results show that the standard deviations of repeatability for the measurement equipment and the system are 0.07 mm and 0.13 mm respectively, which indicates that both the methods can meet the requirement of monitoring the manufacture dimension changes of BIW. Futhermore, the coordinate measuring errors of the system are ±0.2 mm and ±0.8 mm from the two methods, respectively.

关 键 词：通用机器人 视觉检测 全局校准 激光跟踪仪 测量臂 运动学模型 

分 类 号：TP242.6[自动化与计算机技术—检测技术与自动化装置]