基于空间插值的工业机器人精度补偿方法理论与试验

Theory and Experiment of Industrial Robot Accuracy Compensation Method Based on Spatial Interpolation

随着工业机器人技术的不断发展,机器人在工业领域得到了越来越广泛的应用。针对机器人普遍存在重复定位精度高、绝对定位精度低的特点,提出一种改进其绝对定位精度的方法。以D-H运动学模型为基础建立机器人坐标系,并综合考虑机器人各关节参数引入的误差,建立机器人的位姿误差模型。利用该误差模型,通过分析相邻两点间定位误差之间的内在关联提出了定位误差相似度的概念,并在此基础上提出一种基于空间插值的工业机器人精度补偿方法。利用KUKA机器人对提出的精度补偿方法进行验证,试验结果表明,补偿前机器人的绝对定位精度为1～3 mm,补偿后它的绝对定位误差的最大值为0.386 mm,平均值为0.156 mm,较未补偿前有了近一个数量级的提高,从而证明了该方法的可行性和有效性。

With the development of technology of robot, industrial robot is used more and more widely in the industrial field. The industrial robot usually has a high repeat positioning accuracy and a low absolute positioning accuracy. According to Denavit-Hartenberg kinematics model, the robot coordinate system is established, meanwhile the geometric error model is also established by taking account of errors introduced in joint parameters. The inner relationship between positioning accuracy of two adjacent points is discussed by using the error model, and therefore the concept of positioning errors similarity is proposed. Above on this, a method of robot accuracy compensation based on spatial interpolation is proposed. A KUKA robot is introduced to invalidate the proposed method, and the results show that by using the accuracy compensation method the maximum value of the robot positioning error is 0.386 mm, and the mean value is 0.156 mm, which are much more better than the previous values 1-3 mm,thus the method is feasible and effective.