绝对编码光栅的相位细分  

Phase subdivision of absolute coding grating

作　　者：赵勇[1] 苏显渝[1] 李雯[1] 

机构地区：[1]四川大学光电科学技术系,四川成都610064

出　　处：《光电子．激光》2010年第1期91-95,共5页Journal of Optoelectronics·Laser

摘　　要：针对位移精密测量中提高绝对编码光栅的分辨率,提出一种绝对编码的相位细分方法。由自然码或格雷码的多码道光栅组成编码光栅,其基元码道是高频率的罗奇光栅,解码采用傅里叶变换相位计算方法,通过傅里叶变换、空间频域滤波和逆傅里叶变换得到基元码道的相位分布,利用格雷码的级次信息得到展开的相位分布。利用相位分布的线性性质进行线性拟合,实现高分辨率的相位细分。分析了实验原理并进行了提高分辨率的相位细分实验研究,实验结果表明,采用相位细分的方法,经过标定后可大大提高绝对编码光栅的分辨率和测量精度。A phase subdivision of absolute coding is proposed to enhance the resolution of absolute coding grating in displacement measurement.The used grating consists of multiple code-channel grating of Gray Code,and the basic code-channel is high-frequentcy Roche grating.Fourier transform method is adopted in decoding,and the wrapped phase distribution of basic code-channel is obtained by Fourier transform,filtering,and inverse Fourier transform,then the unwrapped phase distribution could be obtained using rank information of Gray Code.And the linearity of phase distribution,high resolution of phase subdivision can be realized via linear fitting.Experimental results show that the resolution and precision of absolute coding grating is enhanced greatly after phase subdivision and calibration.

关 键 词：绝对编码 光栅 相位细分 

分 类 号：O432.2[机械工程—光学工程] TN386.5[理学—光学]