时栅数控转台空间回转位置预测方法研究

Spatial circular position predicting method for time grating CNC rotary table

时栅传感器利用时空变换技术将空域信息变换到时域,以时间测量空间位移。为了研制高精度时栅数控转台,减少动态位置反馈误差,提出了一种回转位置预测测量新方法,利用时空变换技术将时域信息返回到空域。利用时间序列理论对时栅测量值进行建模,从而预测出数控转台未来一段时间内的位置值,并利用当前测量值对前一次的预测误差进行实时修正。介绍了测量数据建模方法和预测系数估计算法。为了验证位置预测方法的有效性,设计了一套动态实验系统。实践证明,数控转台的角位移预测误差为±2″,实现了精密位置预测。

Time grating sensor transforms space domain information into time domain information and measures spatial displacement with time.To develop high precision time grating CNC rotary table and reduce the dynamic position feedback error of the table,a circular position predictive measurement method is proposed for transforming time domain information back to space domain information based on time-space transformation technology.The predicted values of rotary table position are obtained through modeling the measured values of time grating with time series theory,and the latest prediction error is corrected in real time using the current measured value.The modeling method and parameter estimation algorithm are presented.To verify the validity of the position prediction method,a dynamic experiment system was designed.The angle displacement prediction error of the rotary table is ±2″,and the precise position predicting is achieved.