| Author Name | Affiliation | | Xiaoshan Gao | School of Mechanical Engineering & Automation, Beihang University, Beijing 100191, China | | Gang Wang | School of Automation, Beijing University of Posts and Telecommunications, Beijing 100876, China | | Chao Yun | School of Mechanical Engineering & Automation, Beihang University, Beijing 100191, China | | Daxian Hao | School of Mechanical Engineering & Automation, Beihang University, Beijing 100191, China |
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| Abstract: |
| In order to realize high precision industrial operations, based on the POE formula, an effective approach to calibrate the robot's actual base frame (ABF) is proposed. Due to the existence of manufacturing errors, the ABF deviates slightly from nominal base frame (NBF).Using external precision measurement, the ABF can be established only through the three dimension (3D) position of the robot's end-effector.To ensure the orthonormal constraints of rotation matrix as well as the precise solutions, Procrustes Analysis is introduced, where an optimal orthogonal matrix is solved out by the Lagrange Multiplier method and Singular Value Decomposition (SVD). Furthermore, calibration experiment on a serial 6-DOF robot is performed, where a FARO laser tracker is utilized to measure the 3D position. Finally, calibration result indicates that the positioning accuracy has been significantly improved after calibration. The calibration method is also applicable to other similar problems, such as multi-robot coordination and robot hand-eye system calibration. |
| Key words: base frame calibration Procrustes Analysis orthogonality |
| DOI：10.11916/j.issn.1005-9113.16095 |
| Clc Number:TP242 |
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| Descriptions in Chinese: |
| 基于正交Procrustes分析的机器人基坐标系标定方法 高晓珊1，王刚2，贠超1，郝大贤1 （1北京航空航天大学 机械工程及自动化学院，北京 100191； 2北京邮电大学 自动化学院，北京 100876） 摘要:为满足机器人高精度作业要求，基于POE正运动学公式，提出一种基于正交Procrustes分析的机器人基坐标系标定方法。由于制造装配误差的存在，导致机器人实际的基坐标系与理论建模的基坐标系之间存在偏差，前者可以借助外部测量设备采集机器人末端执行器的三维（3D）位置坐标来建立。为求解两个基坐标系之间的变换关系，利用Procrustes分析的几何约束条件，建立拉格朗日乘子罚函数形式的目标方程，通过奇异值分解（SVD）得到最优的正交旋转矩阵。最后，对六自由度串联机器人进行了现场测量与标定实验，实验结果表明该标定方法可以有效解决工业应用环境中机器人的基坐标系标定问题，同时也为机器人手眼标定、多机器人协作基坐标系标定问题提供了参考依据。 关键词：基坐标系；标定；Procrustes分析; 正交性 |
