基于DSP的光栅分度盘及其光栅信号精细分

摘要

对提高光栅的细分准确度进行了研究,提出了一种正切与余切相结合的方法.针对实际光栅信号的不稳定性,利用光栅发讯头输出正切、余切信号峰峰值与直流电平的漂移,自动修正反正切与反余切的查找表格.该方法应用于精密倾光学分读盘测量系统,使细分误差仅与光栅信号第一个采样值和最后一个采样值的精度有关,与测量过程中的光栅信号采样值的误差无关,同时采用DSP处理采样数据,速度更快,并成功应用于光栅分读盘系统,精度为2″.%Enhancing accuracy of grating subdivision is researched, a method which uses tangent and cotangent is brought up. In view of the actual grating signal instability, using the grating signal head output the VPP of tangent, cotangent signal and DC drift, The search form of tangent and cotangent are automatically revised. This method used in precision optical reading measuring system, make the subdivision errors only related to the first sampled grating signal value and the last precision, nothing to do with the process of grating measuring signal sampling value error, and use DSP processing sampling data making speed faster