基于对偶四元数的机器人基坐标系标定方法研究

针对借助激光跟踪仪标定机器人所涉及的坐标系统一问题,对基于空间几何法拟合建立的基坐标系与机器人理论基坐标系的转换关系进行了研究,提出了一种基于对偶四元数法的机器人基坐标系标定方法。利用指数积公式推导了七自由度串联机器人正运动学,建立了基于对偶四元数表示法的机器人基坐标系标定模型,该模型将拟合建立的基坐标系与机器人理论基坐标系之间坐标转换的旋转与平移过程进行了统一描述。研究结果表明,该标定方法可一次性计算出标定方程的旋转部分和平移部分,避免了传统位姿分步计算过程中的误差传递,直接提高了标定精度。这些结论可对于类似机器人手眼标定、多机器人协作基坐标系标定问题提供参考。

Robot base frame calibration method based on dual quaternion

Aiming at the problem of unified coordinate system involved in the robot calibration with the help of laser tracker,the transformation relation between robot nominal base frame and the fitting base frame of spatial geometric method by laser tracker was researched,a calibration method of robot base frame using dual quaternion was proposed and applied.The 7-DOF serial robot kinematics model was established by the product-of-exponential formula,and calibration model for robot base frame using dual quaternion was derived.The results indicate that the calibration method can calculate the rotation and translation of the calibration equation at one time,overcome the error transfer in the traditional pose-step calculation process and improve the calibration accuracy directly.The calibration method is useful to other problem that formulates in the same mathematical form,such as robot hand-eye system calibration and multi-robot coordination.