光栅尺的I-Q平衡式光电编码与解码方法

I-Q Balanced Photoelectric Coding and Decoding Method of Grating Ruler

光栅作为位移、速度和加速度测量的重要器件,在高精度、高速自动化数控反馈闭环系统有广泛应用。为增强其高速测量的可靠性,提出了一种直线光栅尺的I-Q平衡式光电编码与解码方法。主光栅和指示光栅平行放置,光栅常数差别形成莫尔条纹。光电探测单元的每个光电二极管为独立检测通道,按照固定空间频率莫尔条纹相对相位位置分布,并经过独立的、按I-Q平衡式编码与解码方程设计放大倍数的直流运放电路放大,最后按I-Q平衡式编码与解码方程条件分别送入2路加法器,加法器输出就是标准和通用的2路I-Q正交信号,符合自动化设备使用标准。该方法使得自动化数控闭环系统的抗光栅表面污染、抗光电二极管分布位置误差和抗低频振动等能力全面增强,是一种高效、可靠、实用性强的光栅技术。

As an important device for displacement,velocity and acceleration measurement,gratings are widely used in high-precision,high-speed automated CNC feedback closed-loop systems.In order to enhance the reliability of high-speed measurement,a linear encoder with I-Q balanced photoelectric coding and decoding method is proposed.The main grating and the indicating grating are placed in parallel,and the difference in grating constant forms a moiréfringe.Each photodiode of the photodetection unit is an independent detection channel,which is distributed according to the relative phase position of the moiréfringe at a fixed spatial frequency,and is amplified by an independent DC operational amplifier circuit designed according to the I-Q balanced encoding and decoding equation.I-Q balanced encoding and decoding equation conditions are respectively sent to the 2-way adder,and the output of the adder is the standard and general 2-way I-Q quadrature signal,which is in line with the standard for automation equipment.This method comprehensively enhances the automatic numerical control closed-loop system's anti-grating surface pollution,anti-photodiode distribution position error and anti-lowfrequency vibration ability,and is an efficient,reliable,and practical grating technology.