A six-degree-of-freedom surface encoder for precision positioning of a planar motion stage
A six-degree-of-freedom surface encoder for precision positioning of a planar motion stage
复制标题
DOI：
10.1016/j.precisioneng.2013.03.005
复制
发表时间：
2013-07-01
影响因子：
3.6
通讯作者：
Dian, Songyi
中科院分区：
文献类型：
--
作者：
Li, Xinghui;Gao, Wei;Dian, Songyi
本文提出了一种多轴表面编码器，可以测量六自由度（六自由度）的平移位移运动和角运动的平面运动平台。六自由度面形编码器由平面光栅尺和光学传感头组成。使用波长为405 nm、输出功率为25 mW的蓝色激光二极管作为传感器头的光源。将激光二极管发出的光线准直成直径为1.8 mm的平行光束，用分束器将准直光束分成两束，分别投射到光栅周期为0.57 μ m的标尺光栅和参考光栅上。利用两光栅的一级衍射光叠加产生的干涉信号，检测出光栅相对于传感头沿着X、Y、Z方向的三自由度平移运动。利用刻度光栅的零级和负一级衍射光的一部分来检测三个自由度绕X、Y和Z轴的角运动。传感器头设计为具有95 mm（X）x 90 mm（Y）x 25 mm（Z）的尺寸，使得其可以安装在先前开发的平面运动平台上。标尺光栅的光栅面积设计为60 mm（X）x 60 mm（Y），大于40 mm（X）x 40 mm（Y）的载物台移动范围。通过实验对编码器的基本性能进行了测试。(C)2013 Elsevier Inc. All rights reserved.
This paper presents a multi-axis surface encoder that can measure six-degree-of-freedom (six-DOF) translational displacement motions and angular motions of a planar motion stage. The six-DOF surface encoder is composed of a planar scale grating and an optical sensor head. A blue laser diode with a wavelength of 405 nm and an output power of 25 mW was employed as the light source of the sensor head. The light rays from the laser diode were collimated to a parallel beam with a diameter of 1.8 mm. The collimated beam was divided by a beam splitter into two beams, which were projected onto the scale grating and a reference grating with an identical grating period of 0.57 mu m, respectively. The three-DOF translational displacement motions of the scale grating with respect to the sensor head along the X-, Y- and Z-directions were detected from the interference signals generated by superimposition of the first-order diffraction beams from the two gratings. A part of the zeroth-order and the negative first-order diffraction beams from the scale grating were employed for detection of the three-DOF angular motions about the X-, Y- and Z-axes. The sensor head was designed to have a dimension of 95 mm (X) x 90 mm (Y) x 25 mm (Z) so that it can be mounted on a previously developed planar motion stage. The grating area of the scale grating was designed to be 60 mm (X) x 60 mm (Y), which was larger than the stage moving ranges of 40 mm (X) x 40 mm (Y). Experiments were carried out to test the basic performances of the surface encoder. (C) 2013 Elsevier Inc. All rights reserved.