多轴加工非线性误差精确建模与姿态补偿

Accurate Modeling and Tool Orientation Compensation for Nonlinear Errors in Multi-axis NC Machining

分析了多轴数控机床加工中非线性误差产生的原因;基于机床轴空间和刀具空间之间的非线性映射关系,以工件自由曲面为分析对象,建立了反映复杂曲面几何特征的精确非线性误差模型;针对可能出现的超差情况,采用基于矢量平滑的自适应误差控制策略对误差进行补偿。在自主开发的CAM系统内开发了非线性误差模块,基于五轴联动机床加工大型螺旋桨叶片,实现了叶片加工精度的严格控制。

Nonlinear errors during machining process were analyzed for multi-axis NC machining.Based on the nonlinear relationship between machine-axis space and cutter space,an accurate nonlinear error model for sculptured surface machining was established,which reflected the geometry of complex surfaces.In case that nonlinear error exceeds permissible limit,adaptive linearization control strategy was adopted to smooth the tool orientation.The control module for nonlinear errors was developed.At last,a large-scale propeller blade was machined by 5-axis machine tools to validate theory mentioned herein,of which the results indicate the strict control of precision has come true.