五轴数控机床进给系统动态误差影响因素分析

Analysis of the Factors Affecting the Dynamic Error of the Feed System of Five Axis NC Machine Tools

摘要: 本文以双转台五轴数控机床的进给系统为研究对象，分析了直线轴与旋转轴联动加工圆轨迹时跟随误差与轮廓误差的情况。首先基于D-H法的建模原理，运用运动学变换理论基础，建立了五轴联动数控机床运动学模型。其次在进给伺服系统模型的基础上，对X轴和C轴联动空间圆轨迹进行理论推导，仿真分析了不同位置环增益、不同速度时动态误差以及轮廓误差的情况，结果表明，位置环增益和进给速度对进给系统动态误差的影响显著，各轴之间必须保证位置环增益匹配才可以避免较大的轮廓误差。研究结果为五轴数控机床的检测与调整提供了指导。

Abstract: In this paper, the feed system of a five axis NC machine tool with double turntables is taken as the research object, and the following error and contour error when the linear axis and the rotary axis are combined to process the circular path are analyzed. Firstly, based on the modeling principle of D-H method and the theory of kinematics transformation, the kinematics model of five axis CNC machine tool is established. On the basis of the model of the feed servo system, the theoretical der-ivation of the X-axis and C-axis linkage space circle track is carried out, and the simulation analysis of the dynamic error and contour error under different position loop gain, different speed is carried out. The results show that the position loop gain and feed speed have significant effects on the dy-namic error of the feed system, and the large contour error can be avoided only by ensuring the po-sition loop gain matching between the axes. The research results provide guidance for the detection and adjustment of five axis CNC machine tools.