轨迹误差建模的多轴联动机床轮廓误差补偿技术

为了提高数控机床多轴联动加工精度,减小由传动机构和运动部件质量、刚度、阻尼及摩擦等因素造成的轮廓误差,针对交叉耦合控制参数难以选择及容易使系统不稳定的问题,提出了一种针对多轴联动机床进行运动轨迹误差建模和补偿的方法.该方法通过测量机床的典型实际联动轨迹,来建立轮廓误差模型,实现了加工过程轮廓误差的实时估算和补偿.通过对x、y轴工作台的联动轮廓误差建模和补偿实验,证明此方法可以显著减小圆弧及曲率连续变化曲线轨迹的加工误差,从而提高了在高速条件下的数控机床多轴联动的加工精度.

Contour Error Compensation Strategy for Multi-Axis Machining by Trajectory Error Modeling

To improve the machining precision of multi-axis machine tools,diminish its contour error caused by various factors of the transmission mechanism,such as mass,rigidity,damp and friction,and aiming at the difficulty of parameter identification in the cross-coupled control method and the induced system instability,a novel error modeling and compensation strategy for multi-axis machine tools is proposed.The contour error model is established by measuring several contour errors of typical trajectory,and the contour error can be calculated and compensated by the error model during machining process.The new compensation strategy is implemented on a x、y table,which shows that the new approach enables to significantly reduce the contour error of circle and trajectory with continual curvature and improve the multi-axis machining precision,especially for high speed machining.