NC加工位置误差模型及其测量和补偿方法研究

The Finite Element Modeling of NC Machining Position Error and Its Measure and Compensation

机床误差补偿是为了达到"抵消"刀具位置的误差,消除或减少加工误差.从不追溯误差来源的角度,提出了机床加工位置误差有限元模型.这种模型建模方法简捷,既能够准确地表示机床误差及其分布,又能以简单、经济的方法加以标定.误差有限元的网格越密,该模型精度越高.为了高效标定误差有限元网格节点参数,提出了用跟踪激光干涉仪实现机床误差的直接测量方法.同时,提出了基于位置误差有限元模型的实时补偿软件设计方法,介绍了基于华中Ⅰ型数控系统的实验情况.实验证明,位置误差有限元补偿方法是一种提高数控机床精度经济而有效的方法.

The aim of machine tool error compensation is' to counteract' the terminal error of the tool and to eliminate or to reduce the process errors and the authors put forward a terminal error model developed in the finite element method literature regardless of pursuing the error source. The method used is very simple as one can not only express the machine error and their distributions accurately and efficiently, but also calibrate them with simple and economical ways. The higher the model precision is, the more finite lattices are needed. In order to calibrate the finite element lattice nodes of tolerances efficiently, an effective direct measure approach is developed in this article, which is fulfilled by laser interferometer to measure the terminal error of machine tool directly. At the same time, a real time software compensation method based on this finite element terminal error model, is also investigated in the article. The text also illustrates the experiment results based on HUST-1 CNC system. It is proved that this novel method is an effective and economical way to improve the precision of CNC machine tools.