基于正交与插值算法的精密抛光平台综合误差建模与补偿

Comprehensive error modeling and compensation for precision polishing platform based on orthogonal experiment and interpolation algorithm

为了提高四轴抛光平台的加工精度,本文针对以气浮平台和旋转台为主要运动方式的四轴抛光平台进行了几何与热综合误差建模与补偿研究。采用激光干涉仪、温度传感器等测量仪器分别对平台X、Z轴在不同温度下的定位误差进行重复测量与分析,证实了不同进给速度对定位误差没有显著影响。得到了四轴抛光平台X、Z轴的定位误差与温度之间的变化规律。基于正交多项式和插值算法分别建立了X、Z轴的几何与热综合误差模型。根据综合误差模型计算出预测数据曲线,并分别对X、Z轴的7组实验数据进行了数据拟合,拟合残差绝对值均不超过0.2μm。依据预测数据进行了补偿实验。结果显示,补偿后四轴抛光平台在常温下、温升(60 min)下和稳态下的Z轴定位误差分别降低了93.05%、92.45%、85.71%,X轴定位误差分别降低了89.28%、93.59%、93.33%。实验结果证明本文所提出的综合模型及补偿方法精度高,鲁棒性好。

To improve the machining precision of four-axis polishing platforms,ageometric and thermal comprehensive error model and an error compensation method were researched for a four-axis polishing platform with a float platform and a rotation platform.Several kinds of instruments such as laser interferometer,temperature sensor were used to repeatedly measure and analyze respectively the positioning errors of X,Zaxes at different temperatures and to verify that different feeding speeds were no significant influence on the positioning error.The change rules of between position error and temperature change for the polishing platform in X,Zaxes were obtained.Based on orthogonal poly-nomial and interpolation algorithm,the geometric and thermal comprehensive error model of X,Zaxes was established.According to the comprehensive error model,the prediction data curves were calculated,and seven groups of experimental data of X,Zaxes were fitted and the fitting residual error absolute value was verified to be less than 0.2μm.A compensation experiment was carried out according to the forecasting data.The results show that the Xaxis positioning errors of polishing platform under the normal temperature,the temperature rise of 60 min and steady state are respectively decreased by 89.33%,92.45%and 85.7%after compensation,and the Z-axis positioning errors are respectively reduced by 89.23%,93.59% and 93.33% after compensation.The experimental results demonstrate that the presented comprehensive model and compensation method have high precision and good robustness.