【作者】 余建平；

【导师】 陈子辰； 王文；

【作者基本信息】 浙江大学 ， 机械制造及其自动化， 2013， 博士

【摘要】 多自由度的精密位移测量广泛应用于半导体及光学元器件的加工定位、细胞的操纵所需的定位及操纵、超精密机床的运动驱动等,是保证加工、定位、控制精度的关键技术。传统的多自由度精密位移测量系统需要多组单自由度传感器组合而成,存在着结构复杂、误差叠加、价格高等不足,因此研究结构简洁、高精度、低成本的多自由度精密位移测量技术与系统具有重要意义。本论文结合国家自然科学基金“基于平面电容传感器的大行程高分辨率二维位移直接解耦测量方法研究”(No.50875241)和“基于柱状电容传感器的高精度主轴回转误差在线检测方法研究”(No.51275465)等项目,以平面电容传感器为研究对象,研究并建立大行程、高分辨率、多自由度位移直接解耦测量方法与系统。第一章简要阐述超精密位移测量技术的国内外研究现状和发展趋势,并就其中的多自由度精密位移测量技术展开进一步的讨论,分析存在的问题与不足；最后提出论文的研究目标、意义以及主要研究内容。第二章介绍电容传感器实现位移测量的工作原理,提出可以实现大行程位移测量要求的一维栅式平面电容位移传感器(Encoder-like Planar Capacitive Displacement Sensor, EPCDS)。并在此基础上,设计基于EPCDS的大行程、高分辨率二维位移直接解耦测量方法；构建二维EPCDS实验系统,以验证所提出的二维位移直接解耦测量方法；开展误差分析,提出改进的方法。第三章分析电容传感器产生边缘效应的原因,并简要阐述目前消减边缘效应对测量精度影响的几种方法。针对论文提出的EPCDS,利用MAXWELL方程组建立电容量计算模型,通过参数优化,减小并消除边缘效应对传感器测量精度的影响。第四章从原理上剖析影响二维EPCDS测量精度的主要误差源。通过理论分析,建立二维EPCDS的误差模型,量化各个误差源对测量精度的影响,并尝试通过合理的算法减小并消除传感器误差对测量精度的影响。第五章在基于EPCDS的X-Y二维位移直接解耦测量方法的基础上,采用改进的对称化结构设计,提出新型的多自由度EPCDS.在X-Y方向上各增加两组传感电容电极,使得X-Y方向各有四组传感电容,运用单传感器实现五自由度位移的直接解耦测量,包括水平运动方向的大行程线位移(X,Y),以及三个旋转自由度的小行程角位移(θx,θy,θz),并通过仿真分析进行验证。第六章主要阐述EPCDS信号采集与细分系统的软硬件设计,包括微弱电容信号检测电路的设计以及基于LabVIEW的细分算法开发。首先基于运算放大器采用锁相自相关检测原理消减测量电路中噪声对微弱电容信号的影响,实现微弱电容信号的检测；其次设计反正切相移细分算法；最后基于LabVIEW软件构建五自由度位移直接解耦测量软件系统。第七章搭建面向超精密定位的平面电容式五自由度精密位移测量传感器实验装置；然后针对硬件检测电路的稳定性从相移电路、检测电路输出两个方面展开相关实验；最后展开五自由度位移直接解耦测量的对比实验,通过对比不同运动情况下各自由度位移测量的精度、稳定性及解耦性,验证本文提出X-Y-θx-θy-θz五自由度精密位移直接解耦测量方法的正确性与有效性。第八章对论文的研究工作进行总结,并对后续应开展的研究工作进行讨论。更多还原

【Abstract】 Multiple degree-of-freedom (DOF) precision displacement measurement as an indispensable part of precision manufacturing and assembly, is now widely used for the fabrication of semiconductors and optical elements, the positioning and manipulation of cells, the actuation of precision machine tools and etc. However, multiple DOF precision measurement is conventionally realized by stacking multiple single-DOF stage systems, resulting in a bulky metrology prototype involving a complicated structure, errors superposition and high cost. Thus, it is of paramount meaning to propose a fast, simple, effective cost multiple DOF metrology system. On the basis of planar capacitive sensor, thorough study on large scale, high resolution, multiple-DOF precision displacement measurement was presented in this dissertation. The research work is supported by the National Natural Science Foundation of China (Grant No.50875241),"Study on two dimensional long range direct decoupling precision displacement measuring system based on planar capacitive sensor", and the National Natural Science Foundation of China (Grant No.51275465),"Study on cylindrical capacitive sensors for on-line monitoring rotation error of high precision spindle"The dissertation is organized as follows:In chapter1, the backgrounds and significant achievements of precision measurement were introduced. Further discussion on the advantages and shortcomings of multiple DOF precision displacement measurement was then presented. The motivation, meaning and research contents were proposed in the end.In chapter Ⅱ. the basic principle of capacitive displacement sensor was introduced firstly, based on which, a single DOF encoder-like planar capacitive sensor(EPCDS) is proposed for large scale precision displacement measurement, with the discussion of the shortcomings of single DOF precision measurement, a two dimensional long range direct decoupling precision displacement measuring system is constructed, the experimental results implied that two dimensional precision displacement measurement was realized with a single capacitor. Finally, the merits and withdraws were both concluded, potential solutions were proposed.In chapter III, the influences of electric field fringe component was introduced. Feasible methods to diminish whose influences on measuring accuracy is presented either. For EPCDS, a capacitance model with the consideration of electric field fringe component was calculated under MAXWELL’S equations. With an optimized geometric layout, influences of electric field fringe component was reduced.In chapter IV, the major errors of the two dimensional EPCDS were analyzed firstly. Based on the analysis, the sensor model against errors was built. Measurement errors were precisely calculated; and approaches have been carried out to diminish the measurement errors.In chapter V, based on the two dimensional EPCDS, a five-DOF precision displacement measurement system was presented. The capacitor electrodes were rearranged and symmetrically positioned, X-Y long range linear displacement measurement was decoupled from the measurement errors, and extra roll, yaw, pitch angular readouts(θx,θy,θz) were achieved. Finite element analysis(FEA) authenticated the five-DOF precision displacement measurement system.In chapter VI, the signal acquisition system of the five-DOF EPCDS was proposed, including the weak capacitive signal sampling system and signal interpretation algorithm. Firstly, phase locked-in correlation detection was adopted to reduce the effects of noises. Secondly, arctangent phase shifted (APS) interpretation algorithm was presented under Lab VIEW(?) to increase measurement resolution and accuracy.In chapter VII, the five-DOF precision displacement measurement system based on EPCDS was constructed firstly, the stability of signal acquisition system was investigated secondly. Then, experiments of five-DOF displacement measurement were carried out. The experimental results indicated that X-Y-θx-θy-θz displacements measurement was successfully achieved, accuracy and resolution have both been increased.In chapter VIII, the key achievements and innovations of this dissertation were offered, and potential researches in the future were presented in the end.更多还原