双倍精度

Base on the analysis of the grating linear displacement measurement theory,t he measure errors especially the subdivision error of the grating scale,this paper focuses on the theory of switch and merge of dual grating scales'signals,builds the design criteria of high speed high precision displacement measurement by using dual grating sales,designs the switch picking reference with high precision and fast switch and merge method,analyses the errors brought in by switch and merge of the duals grating scales.

针对光栅尺的电子细分信号具有细分误差的特性，本文提出了对莫尔条纹信号不细分的方法以提高双光栅尺信号切换合成值的精度。经过对双光栅计数切换基准、切换与合成特征和规律的探讨，本文设计了实现双光栅尺双重测量、计数值切换合成法的硬件电路，主要通过可编程芯片FPGA，设计了双光栅尺信号处理的各电路模块，如双光栅尺信号四倍频辨向模块、速度判断模块、切换模块、计数值合成处理模块。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。