电容式微位移传感器校准技术的研究

发布时间：2018-06-16 11:51

本文选题：微位移 + 光外差技术　；参考：《山东理工大学》2017年硕士论文

【摘要】：随着科技的不断发展,人类能够测量的量级越来越小,精密测量仪器应运而生。纳米级的位移传感器生产技术已逐渐成熟,但是通过分析国内外现有的线位移传感器校准系统及JJF1305 -2011 (《线位移传感器校准规范》),发现尚未出台一套能够结合光电测试技术且具有针对性的微位移传感器的校准系统。因此,本文主要针对电容式微位移传感器输出电压、电流值较小,现有校准过程较为复杂的特性,研究设计了一套高精度、高分辨率并具有一定实践价值的校准系统,望弥补当前在微位移传感器校准系统方面的缺失。首先,本文介绍了电容式微位移传感器的工作原理,结合激光外差测量技术及声光调制技术建立数学模型,得出位移求解公式,并以此设计了校准系统的原理框图。其次,为实现在一定精度要求下的校准要求,设计了光源稳频模块,选择了声光调制器、激振器、功率放大器及光电二极管;设计了校准系统的电路部分,并结合软件实现校准系统与被校准传感器测量数据在计算机中的实时对比,直观的比较校准结果。根据电容式微位移传感器的结构特性,对其静态特性及动态特性进行校准。为了实现校准系统的高精度要求采用锁相放大器与取样积分技术相结合,降低系统噪声影响。最后,参照JJF1059-1999《测量不确定度评定与表示》的相关规定,对本文提出的电容式线位移校准系统的测量不确定度进行了分析。分析系统中不确定度的来源,根据公式计算得到合成标准不确定度和扩展不确定度,并给出测量不确定度报告。完成了对校准装置的位移标准值的量值溯源,系统溯源结果符合校准系统的误差要求,证明了校准系统的可行性。实验结果表明,在标准正弦信号为1280Hz的频率下,本文提出的电容式微位移校准系统不确定度达到了 0.05%,可以对频率响应在0～10 Hz的电容式、电感式微位移传感器进行校准。
[Abstract]:With the development of science and technology, the order of magnitude of human measurement becomes smaller and smaller, and precision measuring instruments emerge as the times require. The production technology of nano-scale displacement sensor has gradually matured. However, by analyzing the existing calibration system of linear displacement sensor at home and abroad and JJF1305 -2011 (calibration specification of linear displacement sensor), it is found that there is not yet a set of calibration system for micro-displacement sensor which can combine photoelectric measurement technology and has pertinence. Therefore, aiming at the characteristics of capacitive micro displacement sensor, such as output voltage, low current value and complicated calibration process, a set of calibration system with high precision, high resolution and practical value is studied and designed in this paper. Hope to make up for the current microdisplacement sensor calibration system deficiencies. Firstly, the working principle of capacitive micro displacement sensor is introduced in this paper. The mathematical model of laser heterodyne measurement and acousto-optic modulation is established, and the displacement solution formula is obtained, and the principle block diagram of calibration system is designed. Secondly, in order to achieve the calibration requirements under certain precision requirements, the frequency stabilization module of the light source is designed, the acousto-optic modulator, exciter, power amplifier and photodiode are selected, and the circuit part of the calibration system is designed. The real time comparison between the calibration system and the measured data of the calibrated sensor in the computer is realized by combining the software, and the calibration results are compared intuitively. According to the structural characteristics of capacitive micro displacement sensor, the static and dynamic characteristics are calibrated. In order to achieve the high accuracy of calibration system, the phase-locked amplifier and sampling integration technology are used to reduce the noise of the system. Finally, referring to the relevant provisions of JJF 1059-1999 "Evaluation and expression of Measurement uncertainty", the measurement uncertainty of capacitive line displacement calibration system proposed in this paper is analyzed. Based on the analysis of the source of uncertainty in the system, the synthetic standard uncertainty and extended uncertainty are calculated according to the formula, and the measurement uncertainty report is given. The traceability of the displacement standard value of the calibration device is completed. The traceability of the system meets the error requirement of the calibration system and proves the feasibility of the calibration system. The experimental results show that at the frequency of 1280Hz, the uncertainty of the capacitive micro-displacement calibration system proposed in this paper is up to 0.05, which can calibrate the capacitive and inductive micro-displacement sensors with a frequency response of 0 ~ 10 Hz.
【学位授予单位】：山东理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212

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