Most of the existing robot calibration methods have high technical requirements for the installation of end tools and detection sensors as well as other calibration equipments involved, which makes the calibration cumbersome and expensive. This article proposes a novel and easy pose-error calibration method for articulated serial robots based on three-closed-loop transformations. First, the principle of the three-closed-loop transformations of the coordinate systems is introduced, where the loops can be mutually verified to improve the accuracy of the calibration. Then, a hand–eye calibration method that can directly obtain the coordinate conversion between the camera and the tool without need to consider the installation or transformation error of the tool at the robot end is proposed. Furthermore, the entire calibration process is economical without using any expensive special instruments, and the use conditions of the calibration equipments are loose. Finally, experimental results show that the pose error of the robot can be precisely detected and verified by different closed loops.

中文翻译：

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基于三闭环变换的铰接式串行机器人位姿误差校准方法

现有的机器人标定方法大多对末端工具和检测传感器的安装以及涉及的其他标定设备的安装技术要求高，标定繁琐且成本高。本文提出了一种基于三闭环变换的铰接式串行机器人的新颖且简单的位姿误差校准方法。首先，介绍了坐标系三闭环变换的原理，三环之间可以相互验证，提高标定精度。然后，提出了一种无需考虑机器人端工具安装或变换误差即可直接获得相机与工具坐标转换的手眼标定方法。此外，整个校准过程经济，无需使用任何昂贵的专用仪器，校准设备的使用条件宽松。最后，实验结果表明，机器人的位姿误差可以通过不同的闭环精确检测和验证。