螺旋线基准装置测头挠曲误差标定

Calibration of Probe Bending Error in Helix Measurement Standard

为了使螺旋线基准装置的测量原理符合阿贝原则,采用双频激光干涉仪作为长度基准,将干涉仪的反射镜固定在测头测杆端部,激光测长受测杆挠曲误差影响,为此对测头挠曲误差的标定方法进行了研究。通过理论分析将测头挠曲简化为悬臂梁挠曲模型,根据悬臂梁的挠度公式推导测杆挠度和测头压深的线性关系式,计算测杆挠度关键是将挠曲系数求解。对2种不同规格测杆分别开展标定实验,实验结果表明测杆挠度与测头压深呈良好线性关系,基于实验数据进行线性拟合和计算,求解出挠曲系数及测头弹性刚度等参数,实现了对激光测长数据的修正补偿。

In order to make the measuring principle of helix measurement standard adhere to Abbe principle,a laser interferometry measuring system is applied as the standard of length measurement. The reflectors are attached at the end of probe stylus,and laser interferometry will be affected by bending of stylus,so the calibration method of probe bending error is analyzed. Probe bending is simplified as cantilever beam model. Furthermore,the linear mathematical formula between the stylus bending and probe deflection is deduced based on the theory of cantilever beam model,thus the calculation of bending coefficient is the key for determination of stylus bending. The calibration experiment are carried out for two types of stylus. The experiment results show that stylus bending is linear to the probe deflection,so the linear fit and calculation are performed based on the experiment data. Finally,the stylus bending coefficient,probe elastic stiffness are calculated,correction and compensation for laser length measurement is performed as well.