轴旋转法标定中的机器人运动学建模方法研究  

A Robot's Kinematics Modeling Method Using Axis Rotation Calibration Method

作　　者：王杼荣 练少勋 南晓萱 席文明 WANG Zhurong;LIAN Shaoxun;NAN Xiaoxuan;XI Wenming(School of Aerospace Engineering,Xiamen University,Xiamen 361102,Fujian,China)

机构地区：[1]厦门大学航空航天学院,福建厦门361102

出　　处：《机械科学与技术》2024年第5期844-850,共7页Mechanical Science and Technology for Aerospace Engineering

摘　　要：轴旋转法标定是通过依次旋转机器人关节轴获取测量点,利用测量点拟合机器人轴线方程。基于轴线方程,利用两种方法建立机器人运动学方程,第一种方法首先求取机器人各轴理论坐标系相对于基坐标系的变换矩阵,然后基于理论轴线与实际轴线间的微小误差,求取各轴实际坐标系相对于基坐标系的变换矩阵,最后求取六变量相邻变换矩阵。第二种方法是直接利用新MDH法求取实际机器人的相邻变换矩阵,即对于空间交叉轴,求其公垂线确定轴坐标系,对于平行轴,通过交叉轴的公垂线交点向另一轴作垂线,确定另一轴坐标系的x轴方向。比较两种方法发现,第一种方法无法求解各轴的零位偏差,而第二种方法可以解耦求取各轴零位偏差与几何参数。利用牛顿迭代法求解两种模型的逆运动学方程,并用实验和仿真计算比较两种方法的标定效果,其轨迹精度达到−0.83~+0.52 mm。The axis rotation calibration method is to obtain the measuring points by rotating the joint axes of a robot in turn and then use the measuring points to fit its axis equation.Based on the axis equation,two methods are used to establish the kinematics equation of the robot.The first method obtains:1)the transformation matrix of the theoretical coordinate system of each axis relative to the base coordinate system;2)the transformation matrix of the actual coordinate system of each axis relative to the base coordinate system based on the tiny error between the theoretical axis and the actual axis;3)the six-variable adjacent transformation matrix.The second method is to directly use the modified denavit-hartenberg(MDH)method to obtain the adjacent transformation matrix of the actual robot.For the space intersecting axis,the coordinate system of the axis is determined by finding its common perpendicular line.For the parallel axis,the x-axis direction of the coordinate system of other axes is determined by the perpendicular line of the intersection point of the common perpendicular line of the intersecting axis to other axes.The comparison of the two methods finds that the first method cannot solve the zero deviation of each axis,but the second method can decouple the zero deviation and geometric parameters of each axis.The inverse kinematics equations of the two methods were solved with the Newton iterative method,and the calibration effects of the two methods were compared by using experiments and simulations.The trajectory accuracy of the two methods reaches−0.83 mm to+0.52 mm.

关 键 词：轴旋转法 运动学方程 六变量 新MDH法 牛顿迭代法 

分 类 号：TP242.2[自动化与计算机技术—检测技术与自动化装置]