给出了一种基于指数积公式的串联机器人运动学参数标定方法.根据关节旋量坐标的理论值和实际值之间的伴随变换关系将指数积公式改写成包含有关节约束条件的等价形式.对运动学方程取微分得到末端执行器误差与关节旋量误差及零位旋量误差间的线性化模型.给出一种基于最小二乘法的串联机器人运动学参数标定模型,并通过伴随变换的方法实现运动学参数识别过程中关节旋量坐标的更新.一种6自由度串联机器人的标定仿真实验表明参数标定过程能够快速地收敛到稳定值,标定结果能有效地补偿末端执行器的位姿误差.
A kinematics parameter calibration method for serial robots based on the product of exponential (POE) formula is presented. According to the adjoint transformation between the theoretical value and actual value of joint twists, the POE formula is transformed into an equivalent form including the joint constraints. A linearized model describing the relationship between the errors in the end-effector and the errors in the joint twists and in the zero position twist, is obtained by differentiating the kinematics equation. A least-squares kinematics calibration model for serial robots is given and the joint twists are updated through the adjoint transformation in the kinematic parameters identification procedure. A calibration simulation experiment with a 6-DOF (degree of freedom) serial robot shows that the calibration process can quickly converge to the stable values and the calibration result can compensate for the pose errors in the end-effector effectively.