基于虚拟基准点的多测头TCP标定方法  

TCP Calibration Method for Multiple Probes Based on Virtual Reference Points

作　　者：郭文婷 陈东生[1] GUO Wenting;CHEN Dongsheng(Institute of Mechanical Manufacturing Technology,China Academy of Engineering Physics,Mianyang 621900,China)

机构地区：[1]中国工程物理研究院机械制造工艺研究所,四川绵阳621900

出　　处：《计算机测量与控制》2025年第1期106-113,共8页Computer Measurement &Control

摘　　要：以机械臂为本体的接触式测量系统末端携带多测针,各测针相对于法兰的工具中心位置需要进行标定,从而精准获得经多测头测量的目标点位在同一基座标系下的位置;然而,传统六关节机械臂末端TCP标定方法存在随机误差大,标定可靠性低等问题;为降低机械臂多测针协同标定误差,提高接触式测量系统标定可靠性,在经典四点标定法的基础上,引入虚拟外部基准点的概念,利用机械臂及测头自带的测量功能获取法兰中心坐标,采用最小二乘法拟合球心,建立虚拟基准点,减少了人工对针带来的随机误差;通过构建TCP标定解析模型,以测量拟合的球心作为外部基准点解算TCP参数,实现了多测针协同高精度TCP标定;经实验验证对接触式测量系统多测针采用该方法进行测量后,其测量误差降低,能实现0.08 mm精度的TCP标定,证明采用该方法进行标定具有高可靠性和高精度。The contact measurement system with a robotic arm as the main body carries multiple probes at the end,which needs to be calibrated at the tool center position(TCP)of each probe relative to the flange,so as to accurately obtain the position of target point measured by multiple probs in the same base coordinate system.However,traditional TCP calibration methods for six joint robotic arms have the problems of large random errors and low calibration reliability.To reduce the collaborative calibration error of multiple measurement probes for the robotic arm and improve the calibration reliability of the contact measurement system,based on a classic 4-point TCP calibration method,virtual external reference points is introduced,and the robotic arm and probe have the built-in measurement function of achieving the center coordinate of the flange.Least square method is used to fit the spherical center,reducing the random errors by manual operation.The high-precision TCP calibration of multiple collaborative probes are acquired by constructing a TCP calibration analytical model and using the fitted spherical center as an external reference point.Through experimental verification,the measurement system is reduced by using the method,with an accuracy of within 0.08 mm,which identifies that the method has high reliability and precision for calibration.

关 键 词：TCP标定 测量技术 坐标测量 接触式测量 最小二乘法 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置]