摘要
为建立高精度的数控机床综合误差补偿模型,提出一种针对机床定位误差的解耦分离建模方法。通过对数控机床温度场与定位误差进行测量,研究机床在不同工况下温度场与定位误差的变化规律,基于该规律定义机床定位误差敏感度的概念,采用灰色关联度算法建立定位误差敏感度矩阵并优化了测温点。根据机床定位误差变化规律,利用多元回归和GM(1,n)算法对机床几何基准误差和热误差进行解耦分离建模,并将上述模型进行线性叠加构建机床定位误差综合模型。在不同工况条件下对一台VXC-560型加工中心进行在线补偿,试验结果表明机床x轴在冷态条件下的定位误差从11.1μm降低到4.5μm,降幅为59.5%,在热态条件下的最大定位误差由34.9μm降低到8.2μm,降幅为76.5%,并验证了采用误差模型直接驱动机床硬件进行补偿的新思路,具有一定的工程应用前景。
In order to establish a high-precision comprehensive position errors compensation model for CNC machine tools, a positioning error decouple-separating method is put forward. Temperature data and positioning errors are measured for 3-axis CNC machine tools, the variation of temperature fields and positioning error has been studied. Based on this regularity, a new concept of error-sensitive degree is defined, and constructs error-sensitive degree matrix by grey correlation algorithm, and optimizes the measurement point. Though the research of the position error variation, the thermal error and geometric basic error is decoupled and modeled each other by multiple linear regression and GM（1,n） algorithm. Then position error comprehensive model is established by linear superposition method. Though the on-line compensation experiment on VXC-560 type machine tools under different working conditions, the result shows that positioning error of x axis in cold-state is reduced from 11.1μm to 4.5μm, decreasing range is 59.5%.The positioning error ofx axis in thermal state is reduced from 34.9 μm to 8.2 μm, decreasing range is 76.5%, and verifies the new compensation idea of directly driving hardware by a error model of machine tools. It has certain engineering application prospect.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2016年第1期184-192,共9页
Journal of Mechanical Engineering
基金
国家自然科学基金(11176027)
科技部重大仪器设备专项基金(2012YQ130226)
西南科技大学博士基金(14zx7163)资助项目
关键词
定位误差敏感度
机床进给轴
解耦分离
误差模型
补偿
positioning error-sensitive degree
the feed axis of machine tool
decouple-separating
error model
compensation
