title: Absolute Position Sensing Based on a Robust Differential Capacitive Sensor with a Grounded Shield Window.
abstract: A simple differential capacitive sensor is provided in this paper to measure the absolute positions of length measuring systems. By utilizing a shield window inside the differential capacitor, the measurement range and linearity range of the sensor can reach several millimeters. What is more interesting is that this differential capacitive sensor is only sensitive to one translational degree of freedom (DOF) movement, and immune to the vibration along the other two translational DOFs. In the experiment, we used a novel circuit based on an AC capacitance bridge to directly measure the differential capacitance value. The experimental result shows that this differential capacitive sensor has a sensitivity of 2 × 10(-4) pF/μm with 0.08 μm resolution. The measurement range of this differential capacitive sensor is 6 mm, and the linearity error are less than 0.01% over the whole absolute position measurement range.
authors.affiliation: School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150080, China. baiyang@hit.edu.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Bai
authors.affiliation: School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150080, China. luyf@nim.ac.cn.|National Institute of Metrology, Beijing 100013, China. luyf@nim.ac.cn.|Key Laboratory for the Electrical Quantum Standard of AQSIQ, Beijing 100029, China. luyf@nim.ac.cn.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Lu
authors.affiliation: School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150080, China. hupc@hit.edu.cn.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Hu
authors.affiliation: School of Instrumentation Science and Opto-Electronics Engineering, Beihang University, Beijing 100191, China. wywanggang163@163.com.
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of Electrical Engineering, Tsinghua University, Beijing 100084, China. xujinxinthu@126.com.
authors.forename: Jinxin
authors.initials: J
authors.lastname: Xu
authors.affiliation: School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150080, China. zengtao806@sina.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Zeng
authors.affiliation: National Institute of Metrology, Beijing 100013, China. lzk@nim.ac.cn.|Key Laboratory for the Electrical Quantum Standard of AQSIQ, Beijing 100029, China. lzk@nim.ac.cn.
authors.forename: Zhengkun
authors.initials: Z
authors.lastname: Li
authors.affiliation: National Institute of Metrology, Beijing 100013, China. zzh@nim.ac.cn.|Key Laboratory for the Electrical Quantum Standard of AQSIQ, Beijing 100029, China. zzh@nim.ac.cn.
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150080, China. jbtan@hit.edu.cn.
authors.forename: Jiubin
authors.initials: J
authors.lastname: Tan
keywords: capacitive sensor; fringe effect; length metrology