工业机器人视觉测量系统的在线校准技术  

Online Calibration of Visual Measurement System Based on Industrial Robot

作　　者：王一[1] 刘常杰[1] 杨学友[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：《机器人》2011年第3期299-302,331,共5页Robot

基　　金：国家863计划资助项目(2008AA042407);国家自然科学基金资助项目(50805105)

摘　　要：汽车车身总成、分总成的加工过程中应用工业机器人视觉测量系统对关键尺寸进行在线实时监测.机械臂及环境温度变化导致杆件和关节热膨胀变形,造成测量结果产生温度漂移.本文提出了一种在线校准方法.首先根据机器人的D-H正向运动学模型和微分运动学模型建立末端关节坐标系的定位误差模型,然后结合轴动实验并利用多元线性回归方法确定受温度变化影响最为显著的机器人连杆参数,最后建立基于基准球的温度误差补偿模型.现场测量数据表明,该方法能将温度变化引起的测量误差控制在0.05 mm左右,并且适应生产线的正常节拍.Visual measurement system based on industrial robot is applied to the online and real-time monitoring and inspection of key dimensions in the process of automobile body assembly and subassembly.Temperature variations of the manipulator and environment lead to expansion or deformation of links and joints,therefore cause the temperature drift error. An online calibration approach is proposed.Firstly,positioning error model of the end-effector is established by adopting D-H forward kinematics and differential kinematics.Secondly,combining with thermal experiments on axis rotation,link parameters that change significantly because of robot＇s temperature variation are determined by using multivariate Unear regression method.At last,thermal error is compensated by using a reference sphere.Practical measurement results show that the measurement errors caused by temperature variation can be reduced to about 0.05 mm and the approach can meet the requirement of the production tact.

关 键 词：工业机器人 视觉测量 温度漂移 多元线性回归 

分 类 号：TP241.2[自动化与计算机技术—检测技术与自动化装置]