基于三点法的机床主轴回转误差在线测试技术研究

Study on the Online Test of Spindle’s Radial Error ofMachine Tool Base on Three Pint Method

摘要:

主轴回转误差是评价机床性能的重要指标,为了提高主轴回转误差的分离精度,在数据采集和处理过程中,提出了两种有效的方法：采用变频率数据采集方法,确保了在不同转速下采集得到的数据的谐波分量相同,使误差分离精度不会因转速的升高而降低；为了消除环境中白噪声对误差分离精度的影响,在同一稳定转速下对主轴轮廓连续采集十个周期的数据,利用集合平均滤波方法消除混合在测试数据中的白噪声。搭建了试验系统,利用提出的方法分离出了机床主轴在不同转速下的回转误差、圆度误差和安装偏心差,验证了方法的有效性。

Abstract:

The spindle radial error is one of a most significant factor in evaluating machine tool performance. To improve the accuracy of the dynamic spindle radial error measurement, this paper presented some development of the three point method. The floating sample frequency data acquisition method is used to ensure the number of the harmonic components under different spindle speeds to be the same. So that, the error separation accuracy would not decrease with the increase of the spindle speeds. In order to avoid the effect of the white noise mixed in the measured data, the spindle profile was sampled at discrete time intervals for ten revolution speeds. After that, the ensemble averaging method was used to eliminate the white noise. An experiment system is set up to measure the dynamic spindle radial with the proposed method. The pure dynamic spindle radial error, roundness error and eccentric error under different spindle speed are obtained, and the results verity that the presented method can improve the accuracy of the spindle radial error measurement.