机床工作台精度测试的球杆仪空间PPSPS机构方法

A Spatial Five-bar Linkage PPSPS for Ball-bar to Test Accuracy of Machine Table

提出了球杆仪测试机床两轴工作台精度的机构学分析方法。建立了球杆仪测试机床两轴工作台精度的空间PPSPS五杆机构模型,包括球杆仪的两个球副(S)和一个移动副(P)以及机床工作台的两个移动副(P);给出了基于机构模型的比例不匹配、不垂直度、反向越冲和反向间隙的误差辨识方法。实验结果表明,PPSPS机构模型可以一次辨识出球杆仪安装位置误差、机床移动副的方向偏差和移动副的误差运动,提高了测试效率; PPSPS机构法不作平面假设,测试结果与安装位置无关。

A novel mechanism model of PPSPS is presented in the paper for testing the accuracy of machine table with two P-pairs.The spatial five-bar linkage PPSPS is comprised of a ball-bar with two S-pairs and one P-pair and two P-pairs of the machine tool.Some key accuracy indexes of the P-pairs and their drive systems,such as proportion mismatch,non-perpendicularity,reversal spike and backlash,can be obtained through the PPSPS model.The experimental results show that the mounting position errors,the directional offset and the motion errors can be identified by kinematic synthesis of the PPSPS mechanism using the discrete data measured by the ball-bar,simultaneously.The accuracy model of spatial five-bar linkage PPSPS for ball-bar test of the machine table is independent of the mounting position errors and the assumption of planar motion.