Huang Hsueh-Liang, Liu Chien-Hung, Jywe Wen-Yuh, Wang Ming-Shi, Fang Te-Hua
Department of Engineering Science, National Cheng-Kung University, Tainan, Taiwan 701, Republic of China.
Rev Sci Instrum. 2007 Jun;78(6):066103. doi: 10.1063/1.2743165.
In this study, a laser linear encoder with three degrees of freedom (3-DOFs) based on diffraction and interference was developed to measure the linear displacement and two angular errors of a linear moving stage. Parts of the linear motion errors induced from the two angular errors can be calculated by this prototype 3-DOF laser encoder. It was an effective method for online error calculation and compensation to improve precision stage performance. This new function was superior to other laser encoders. The verification results showed that the resolution is 20 nm. It detected displacements relative to an external grating scale with accuracy of about +/-150 nm for a measuring range of +/-1 mm, and detected the angular errors with related accuracy of about +/-1 arc sec for a measuring range of +/-100 arc sec.
在本研究中，开发了一种基于衍射和干涉的具有三个自由度（3-DOF）的激光线性编码器，用于测量直线运动平台的线性位移和两个角误差。由这两个角误差引起的部分直线运动误差可通过该原型3-DOF激光编码器进行计算。这是一种用于在线误差计算和补偿以提高精密平台性能的有效方法。这一新功能优于其他激光编码器。验证结果表明，分辨率为20 nm。在±1 mm的测量范围内，它相对于外部光栅尺检测位移的精度约为±150 nm，在±100 arc sec的测量范围内，检测角误差的相关精度约为±1 arc sec。
