基于球杆仪的直线轴位置相关误差辨识研究

针对多轴机床空间误差检测及辨识方法成本高、时间长等问题,提出一种新的基于球杆仪测试的直线轴位置相关几何误差辨识方法。分别建立各平面内轴运动误差模型,并采用多项式对误差元素预拟合,以常规的三平面圆弧轨迹测量获取误差数据,并基于最小二乘法求解拟合系数,替代直接对误差元素具体数值求解的传统方法,实现对各直线轴位置相关误差元素的辨识。通过实验验证了辨识结果的正确性和有效性,该方法对机床直线轴误差辨识、补偿具有参考价值。

Research on position dependent error identification of linear axes based on double ball bar

Aiming at the problems of high cost and time consuming in volumetric error detection and identification of multi axis machine tools, a novel identification method for linear axis position dependent geometric error based on double ball bar test is proposed. Firstly, the error models of the axis motion in various planes are established, respectively; and the error element of each axis is pre fitted with respect to its position using polynomial. Then, the comprehensive error in each plane is obtained with conventional three plane circular arc trajectory measurement. Finally, the fitting coefficients are solved based on the least square method, which replaces the traditional method that directly solves the specific value of error element; and the position dependent geometric error element identification of linear axes is realized. The experiment results verify the correctness and efficiency of the proposed method. The method has reference significance for the linear axis error identification and compensation of CNC machine tools.