基于指数积公式的串联机构运动学参数辨识实验

Experimentation on Identifying the Kinematic Parameters of Serial Mechanism Based on the Product-of-Exponential Formula

将指数积公式引入基于关节运动轨迹的串联机构运动学参数辨识.利用坐标测量仪测量各关节的运动轨迹,处理测量数据,得到各关节的运动轨迹方程.根据指数积公式对移动副和转动副的定义,直接从关节运动轨迹方程得到实际的关节旋量和实际的关节变量计数当量,从而避免了繁琐的各连杆坐标系的构建过程和坐标变换矩阵的还原过程.该方法已用于数字化脑立体定向仪的运动学参数辨识.实验结果表明,方法有效并可用于一般串联机构运动学标定.

The product-of-exponential（POE） formula is introduced into the kinematic parameter identification based on joint trajectories for serial mechanism.Each joint trajectory is measured by CMM（coordinate measurement machine）.Then, equations describing each joint trajectory can be obtained by processing the measurement data.According to the definition of the revolute joint and the prismatic joint in POE formula＇s convention,the actual twists and actual pulse-count equivalents of joint variables can be obtained directly from these equations without the complicated procedures of the link coordinate frames＇ construction and these coordinate transformation matrixes＇ reconstruction.The method is implemented to identify the kinematic parameters of the digital brain stereotactic apparatus.The experimental result shows that the method is effective and can be applied to the kinematic calibration of the general serial mechanism.