卧式加工中心空间定位精度分析与补偿

Analysis and Compensation of Spatial Positioning Accuracy of Horizontal Machining Center

为解决数控机床空间定位精度建模不完备及传统逆向叠加补偿存在残差的问题,提出了一种卧式加工中心空间定位精度分析与补偿技术。以某卧式加工中心为研究对象,以旋量理论为基础,在分析机床运动链的基础上,推导计算了两卧式加工中心运动链的运动学正解,并结合21项几何误差分析,构建该卧式加工中心空间定位精度模型;其次,利用十二线法辨识21项几何误差,并输出该机床空间定位精度预测离散图;然后,基于空间对角线测试验证该卧式加工中心空间定位精度模型的准确性;最终,基于NC代码优化补偿技术实现了空间定位精度补偿。结果表明:空间定位精度模型预测值与实际平均值相对偏差最大不超过2μm,且NC代码优化补偿技术的补偿效率最高为8875%。

In order to solve the problem of incomplete modeling of spatial positioning accuracy of NC machine tools and the residual error of traditional reverse superposition compensation,a spatial positioning accuracy analysis and compensation technology for horizontal machining center was proposed.Taking a horizontal machining center as the research object,based on the spinor theory and the analysis of the machine tool motion chain,two forward kinematics solutions of the horizontal machining center motion chain were deduced and calculated,and the spatial positioning accuracy model of the horizontal machining center was constructed based on the analysis of 21 geometric errors;21 geometric errors were identified by using the twelve line method,and the discrete diagram of spatial positioning accuracy prediction of the machine tool was output;then,the accuracy of the spatial positioning accuracy model of the horizontal machining center was verified based on the spatial diagonal test;finally,the spatial positioning accuracy compensation was realized based on NC code optimization compensation technology.The results show that the maximum relative deviation between the predicted value of the spatial positioning accuracy model and the actual average value is no more than 2μm,the highest compensation efficiency of NC code optimization compensation technology is 88.75%.