大型数控龙门铣床几何误差补偿方法研究

Method of geometric error compensation for large CNC milling machine

针对大型数控龙门铣床几何误差的问题,建立了大型数控龙门铣床的几何误差模型,分析了大型数控龙门铣床的几何误差源;利用API(T3)激光跟踪仪高精度大尺寸的测量特点及数据处理能力,提出了X、Y、Z轴线位移误差、角位移误差及各轴间垂直度误差的辨识算法,通过激光测量与计算准确地辨识了大型数控龙门铣床的几何误差;建立了大型数控龙门铣床加工空间几何误差数学模型,采用基于对象的事件驱动机制的程序设计语言Visual Basic开发了几何误差补偿软件,实现了几何误差补偿;现场检测了大型数控龙门铣床空行程平面运动轨迹及工件的平面度。研究结果表明,该方法使平面加工精度提高了50.77%,并验证了几何误差模型的正确性及几何误差补偿方法的有效性。

Aiming at geometric error of CNC milling machine,the modeling of milling machine＇s geometric error was established.The geometric error sources of the milling machine were analyzed.With the high accuracy and large scale measurement and data processing capability of the API （T3） laser tracker,the identification algorithm of the three axis＇s displacement error,angular displacement error and perpendicularity error were put forward,geometric errors of CNC milling machine were accurately identified by laser measurement and calculation.Milling space geometric error mathematical models of CNC milling machine was established.Based on the milling machine＇s geometric error compensation model,the geometric error compensation software was developed by using object oriented programming method.The results indicate that the plane machining accuracy is improved 50.77％,which can verify the effectiveness and accuracy of compensation method.