Calibration method of capacitance sensor for particle accelerator wire position measurement
-
摘要: 在高能同步辐射光源中,为了提高磁铁的准直精度,采用磁中心代替机械中心进行磁铁标定,通过振动线或旋转线等技术获得磁铁的磁中心位置,以及通过电容式位移传感器测量得到丝线的位置,从而实现磁中心与准直靶标的关联。为了实现丝线位置的高精度测量,必须对电容传感器进行精确标定,因此介绍了一种电容式位移传感器,并对其标定方法进行了研究,提出了网格化的数据采集方式以及高阶多项式拟合的数据处理方法,搭建了传感器标定平台并开发了相应的标定控制程序,实现了对传感器的自动控制、数据采集和高精度标定过程。经过分析与对比,标定后的电容传感器达到μm级的位移测量精度,为磁铁的高精度准直提供了基础。Abstract: To improve the alignment accuracy of the magnet in high energy synchrotron radiation source, the magnetic center is used instead of the mechanical center to calibrate, the magnetic center position of the magnet is obtained by vibration wire or rotation wire technology, and the position of the wire is measured by capacitive sensor, so as to realize the association between the magnetic center and the collimation target. To achieve high precision measurement of wire position, it is necessary to calibrate capacitance sensor accurately. In this paper, a kind of capacitive sensor is introduced and its calibration method is studied, the data acquisition method of grid and data processing method of high order polynomial fitting are proposed, the sensor calibration platform is built and the corresponding calibration program is developed, and the automatic and high precision calibration of the sensor is realized. Analysis and comparison show that the calibrated capacitance sensor has achieved the displacement measurement accuracy of μm level, which provides a basis for high-precision collimation of magnets.
-
Key words:
- vibration wire /
- capacitive displacement sensor /
- calibration /
- polynomial fitting /
- precision analysis
-
表 1 第一阶段长期稳定性测试
Table 1. Phase I long term stability test
X/μm Y/μm X/μm Y/μm average method pairwise cycle method maximum deviation 1.6 6.2 3.8 7.3 sensor 011 minimum deviation −2.5 −3.5 −2.9 −7.6 standard deviation 0.8 1.7 1.0 2.2 maximum deviation 3.6 5.7 4.4 10.7 sensor 015 minimum deviation −3.2 −5.8 −4.1 −7.0 standard deviation 1.5 1.9 1.9 2.9 表 2 第二阶段长期稳定性测试
Table 2. Phase II long term stability test
X/μm Y/μm X/μm Y/μm average method pairwise cycle method maximum deviation 5.6 6.9 10.6 7.4 sensor 011 minimum deviation −2.2 −3.5 −12.3 −6.9 standard deviation 1.0 1.3 1.5 1.9 maximum deviation 1.7 5.7 2.2 7.5 sensor 015 minimum deviation −1.5 −2.5 −2.0 −7.3 standard deviation 0.7 1.7 0.9 2.4 表 3 第三阶段长期稳定性测试
Table 3. Phase III long term stability test
X/μm Y/μm X/μm Y/μm average method pairwise cycle method maximum deviation 5.9 6.1 4.5 6.5 sensor 011 minimum deviation −3.6 −4.4 −4.7 −5.6 standard deviation 1.0 1.6 1.0 1.9 maximum deviation −2.6 4.7 2.9 6.8 sensor 015 minimum deviation −2.7 −3.5 −3.5 −6.5 standard deviation 0.7 1.4 0.9 1.9 -
[1] 吴蕾, 王小龙, 李春华, 等. 振动线准直技术的原理和研究概述[J]. 强激光与粒子束, 2013, 25(10):2479-2486 doi: 10.3788/HPLPB20132510.2479Wu Lei, Wang Xiaolong, Li Chunhua, et al. Theory and research overview of vibrating wire technique[J]. High Power Laser and Particle Beams, 2013, 25(10): 2479-2486 doi: 10.3788/HPLPB20132510.2479 [2] 吴蕾. 振动线测量技术研究[D]. 北京: 中国科学院高能物理研究所, 2016Wu Lei. Research of vibrating wire measurement technique[D]. Beijing: University of Chinese Academy of Sciences, 2016 [3] 汪鹏. 电容式非接触静力水准传感器的研制[D]. 合肥: 中国科学技术大学, 2013Wang Peng. Development of capacitive non-contact static leveling sensor[D]. Hefei: University of Science and Technology of China, 2013 [4] Herty A. Micron precision calibration methods for alignment sensors in particle accelerators[D]. Nottingham Trent University, 2009. [5] 刘红丽, 张菊秀. 传感与检测技术[M]. 北京: 国防工业出版社, 2007Liu Hongli, Zhang Juxiu. Sensor and detection technology[M]. Beijing: National Defense Industry Press, 2007 [6] 孙建民, 杨清梅. 传感器技术[M]. 北京: 北京交通大学出版社, 2005Sun Jianmin, Yang Qingmei. Sensor technology[M]. Beijing: Beijing Jiaotong University Press, 2005 [7] 阮玉芳. 中国散裂中子源直线束测研究[D]. 北京: 中国科学院研究生院, 2010Ruan Yufang. The study of the beam instruments for CSNS linac[D]. Beijing: Graduate University of Chinese Academy of Sciences, 2010 [8] 唐郑, 何晓业, 王巍, 等. 用于粒子加速器位置监测的线位置探测器静态特性的标定[J]. 原子能科学技术, 2016, 50(6):1127-1131Tang Zheng, He Xiaoye, Wang Wei, et al. Static characteristic calibration of wire position sensor for position monitoring in particle accelerator[J]. Atomic Energy Science and Technology, 2016, 50(6): 1127-1131 [9] 王兵团, 张作泉, 赵平福. 数值分析简明教程[M]. 2版. 北京: 高等教育出版社, 1984Wang Bingtuan, Zhang Zuoquan, Zhao Pingfu. Concise tutorial on numerical analysis[M]. 2nd ed. Beijing: Higher Education Press, 1984 [10] 费业泰. 误差理论与数据处理[M]. 7版. 北京: 机械工业出版社, 2015Fei Yetai. Error theory and data processing[M]. 7th ed. Beijing: China Machine Press, 2015