电容式位移传感器的线性度标定与不确定度评定

由于光刻投影物镜装调中电容传感器的线性度指标不能够满足位移调节精度的需求,本文提出了一种提高电容传感器测量线性度的方法。该方法采用压电驱动器提供位移进给;采用高精度激光测长干涉仪校准电容传感器的线性度,提供位移反馈以保证运动控制精度。采用高阶曲线拟合方法得到拟合系数对传感器线性度进行在线标定;对标定实验中的环境、安装、机构以及控制等进行不确定度分析与评定以保证电容传感器的线性度测量精度;最后进行电容传感器线性度的标定实验。实验结果表明:本文提出的线性度标定方法能够减小各误差项对于测量结果的影响,标定后传感器线性度由0.047 14%提高至0.004 84%,近一个数量级,并且线性度重复性较高,重复性偏差为0.38nm,全行程内线性度的合成不确定度为5.70nm,能够满足光刻物镜中位移控制精度的需求。     

基于霍耳元件的新型燃油液位传感器的设计

针对当前常用的燃油液位传感器的缺点,设计了一个新型燃油液位传感器,该传感器利用霍耳元件输出的电压与所加的磁场成线性关系,从而反应出剩余燃油液位的高低.该传感器具有线性度好,测量精度和分辨率高的特点,同时该传感器的放大电路具有线性校正功能,使输出更具线性.     

风速传感器回归方程的不确定度评定方法研究

风速传感器线性回归方程的不确定度是进行计量确认的重要参数。文章根据测量不确定度评定理论,详细分析了风速传感器线性回归方程测量不确定度的误差来源,提出了基于最小二乘法评定风速传感器线性回归方程不确定度的方法,并介绍了评定步骤。为了清楚展示评定过程,列举了气象用风速传感器线性回归方程测量不确定度的评定实例,得到校准结果为V=-(0.56+0.99V′)m/s,U=±0.74m/s。结果表明:基于最小二乘法评定风速传感器线性回归方程的不确定度是可行的,此方法也可扩展到线性测量系统的不确定度评定。     

基于转角差法的扭矩传感器设计

为满足汽车传感器集成化、智能化的需要,解决接触式扭矩传感器的不足之处,设计了一种非接触式扭矩传感器,为汽车电动助力转向系统(Electric Power Steering,EPS)提供扭矩信号。扭矩测量采用差角的方法,利用巨磁阻角度传感器芯片获得角度数据,微控制器对角度数据计算处理后通过控制器局域网络(Controller Area Network,CAN)接口输出扭矩信号。该传感器具有无机械磨损、线性度高、性能稳定等特点,并且可以方便地实现绝对角度测量的功能。实验测量表明,该传感器表现出良好的线性特性。     

线结构光传感器的静态性能测试研究

针对线结构光传感器各项静态性能参数对其测量精度影响的问题,设计了一套线结构光传感器静态性能测试方案。在高精度移动平台上使用二级量块、纳米定位台和激光干涉仪,对传感器的重要静态性能参数,如稳定性、重复性和线性度进行了分析,量化了各项静态性能参数对传感器测量精度的影响;以二级量块的工作面作为传感器测试试验的测量表面,结合高精度移动平台实现了传感器全测量区域的测试;使用激光干涉仪对移动平台的定位误差进行了补偿,提高了测量结果的可信度。研究结果表明:传感器需1 h的时间进行稳定来保证测量精度,其测量区域的中部重复性最佳,该区域重复性均值为0.418μm;传感器线性度对其测量精度影响最大,由传感器非线性引起的误差最大为11.2μm。     

微波叶尖间隙传感器信号校准研究EI北大核心CSCD

利用微波雷达传感器测量叶尖间隙时,传感器存在信号泄露、背景回波叠加、电路元器件不平衡以及空间滤波效应等问题,根据这些问题的来源及影响机理,提出了一种具有环境适应性的传感器误差模型,通过将模型从空间域变换到频率域并优化误差提取算法,建立了一套提高传感器线性度、减小测距误差的校准方法。同时,选用小型24 GHz雷达传感器构建了模拟叶尖位移测量平台,使用该校准方法后,传感器线性度由±13.79%提高到±1.57%。拟合标准距离与测量值后,量程内最大测距误差下降到0.021 3 mm,最大标准差下降到0.019 7 mm。该方法有利于提高微波叶尖间隙测量精度。     

用于假手指尖的光纤光栅触觉力传感器研究

针对现有假手触觉测量常用的薄膜压力传感器精度不佳、线性度差、迟滞性高等问题,研究了一种可安装于假手指尖的光纤布拉格光栅触觉力传感器。首先,通过传感单元的微小化结构设计,可以将施加的外力转化为光纤承受的轴向力;进而,通过有限元对传感器结构参数进行优化,提高了光纤光栅对于压力的灵敏度;然后,围绕假手指尖应用的需求,制作了这种光纤布拉格光栅触觉力传感器;最后,对该传感器进行了性能标定、对比分析和应用抓取3个实验分析,实验结果表明:该传感器压力灵敏度为0.103 8 nm/N,线性度R~2为0.998,重复性误差为1.32%和迟滞性误差为2.19%;与现有的薄膜压力传感器对比,该传感器的线性度和重复度都更高,迟滞性更低。     

一种优化位移传感器线性度的方法

目前大多数位移传感器在使用过程中由于线性度的问题导致测量数据与真实值之间有着一定的误差,使位移传感器不能够很理想地工作。本文以实例的形式介绍了一种优化位移传感器的线性度的方法即拉格朗日(Lagrange)插值法。通过实例与误差分析表明,该方法是可行的,而且方法操作简便。     

基于MXT9030与STM32的电容式倾斜仪

利用弹性优良的铍青铜材料作为振动元件来制作倾角传感器,计算了倾角传感器铍青铜元件偏角和输出电压之间的关系。并在此倾角传感器基础上设计了一款典型的三明治式电容式倾斜仪。采用专用的电容检测芯片MXT9030将倾角传感器的电容信号转换为电压信号,同时通过微控制器STM32的控制协助提高传感器的线性度。实验结果显示,该倾斜仪测量范围广,线性度良好。     

微波叶尖间隙传感器信号校准研究

利用微波雷达传感器测量叶尖间隙时,传感器存在信号泄露、背景回波叠加、电路元器件不平衡以及空间滤波效应等问题,根据这些问题的来源及影响机理,提出了一种具有环境适应性的传感器误差模型,通过将模型从空间域变换到频率域并优化误差提取算法,建立了一套提高传感器线性度、减小测距误差的校准方法。同时,选用小型24 GHz雷达传感器构建了模拟叶尖位移测量平台,使用该校准方法后,传感器线性度由±13.79%提高到±1.57%。拟合标准距离与测量值后,量程内最大测距误差下降到0.021 3 mm,最大标准差下降到0.019 7 mm。该方法有利于提高微波叶尖间隙测量精度。     

PCB型Rogowski线圈的设计与特性分析

设计了一种新型的电流传感头-PCB型Rogowski线圈,介绍了其工作原理及增大互感的方法.基于MATLAB软件,对影响线圈动态性能的参数进行了数学分析,得出了线圈优化设计的规律.在此基础上,优选线圈参数,设计了由PCB型Rogowski线圈和积分器组成的测量系统,并对其灵敏度和频率特性进行了分析计算.结果表明,该系统具有较高的灵敏度和良好的频率特性,能满足电力系统中对大电流的测量要求.     

光纤电流互感器中Rogowski线圈的设计与分析

Rogowski线圈作为传感头是光纤电流互感器的关键部分,文章分析了Rogowski线圈的测量原理和等效电路,得出了测量关系,并根据分析设计了一个Rogowski线圈。实验表明该Rogowski线圈具有良好的线性度;频率特性分析显示该Rogowski线圈有非常充裕的带宽,进而为设计高精度的光纤电流互感器奠定了基础。     

直流叠加脉冲电流波形宽频带电流传感器

提出了一种用于测量直流叠加脉冲电流波形的电流传感器。该传感器由两个磁芯组成,一个工作于磁通门状态,另一个基于罗氏线圈原理。为了将磁通门与罗氏线圈检测技术集成在一起,引入了一个反馈绕组,有效克服了脉冲磁场与直流磁场对磁芯工作状态的影响。基于理论分析制作了样机。实验结果表明,所提出的电流传感器能有效测量直流叠加脉冲电流波形:有效测量频带为340 k Hz,直流分量的测量误差为0.6%;低频段与高频段交点处的测量误差最大,最大测量误差为1.5%。     

Effect of geometrical parameters on high frequency performance of Rogowski coil for partial discharge measurements

Partial discharges (PD) in a power system component is a sever threat, indicating a high likelihood of the imminent and complete failure of the insulation. The reliability of partial discharge diagnostics depends upon the design and accuracy of the measuring sensors. In this paper the Rogowski coil is employed as a PD measuring sensor. The selection of suitable geometrical parameters has been identified as an important aspect regarding the proper operation and installation of the coil around the under test power component. These parameters significantly affect the measuring performance of the coil in terms of its sensitivity and bandwidth. The measurement performance of different geometrical designs for the high frequency Rogowski coils is evaluated. The variation in parameters such as core and coil diameter, diameter of the copper wire used for winding and number of turns, has been experimentally investigated. In addition the return winding, as a non-conventional method of creating a return loop for the Rogowski coil, is compared with a return wire (loop) to analyze sensor performance. The comparative study of variation in mechanical design features provides a brief guideline to select the optimal design of the coil.     

A miniaturised sensor for deep hole diameter measurement

A miniaturised displacement senor for deep hole measurement is reported in this paper. By exploiting the induced eddy current effects detected by chip coils, the sensor generates a ’digital’ signal. The sensor chip coil can be manufactured by the similar processes to those used for manufacturing a printed circuit board (PCB) which allows them to be miniaturised. The paper elaborates on the construction and mechanism by which the displacement is directly transferred to a frequency output. It also reports on the transducer, which uses two contact probes for transmitting the displacement to a noncontact sensing element. Experimental results demonstrate the stability, linearity, measurement range and accuracy of the sensor system.     

用于冲击电流测量的自积分式Rogowski线圈的研究

文中介绍了一种自制的自积分式Rogowski线圈配合示波器所组成的冲击电流测量系统的基本原理,采用标准电阻对该Rogowski线圈的测量结果进行了实验校准,并对校准实验数据进行处理.从处理结果看,该Rogowski线圈具有较好的冲击电流测量精度.     

Rogowski coils: theory and experimental results

The theory is given of the voltage output of a Rogowski coil excited by a current pulse flowing along the axis of the coil. In this theory the Rogowski coil is considered as a delay line. The results do not differ from those obtained usually by considering the coil as a voltage source dphi/dt with an inductive output impedance. Details are also given of the design of two Rogowski coils and their working modes are fully analyzed.     

New printed circuit boards magnetic coils in the vacuum vessel of J-TEXT tokamak for position measurement

Four sets of magnetic diagnostic coils, which are printed on machinable ceramic printed circuit boards (PCB), are designed, fabricated, installed, and tested in the Joint Texas Experimental Tokamak (J-TEXT) vacuum vessel for detecting the plasma radial and vertical displacements relative to the geometric center of the vacuum vessel in Ohmic discharges. Each coordinate is determined by a pair of variable cross-section Rogowski and saddle coils, which measure the tangential and normal magnetic fields (relative to the coil surface). These coils are suitable for mass production and offer advantages in vacuum compatibility and temperature tolerance that are important for J-TEXT. Position measurements using PCB coils are compared with those from soft x-ray image system and match the position well.     

Analysis of damping resistor’s effects on pulse response of self-integrating Rogowski coil with magnetic core

A self-integrating Rogowski coil with magnetic core is investigated for accurate measurement of high-impulse current in this paper. Usually, the distributed parameters of Rogowski coil generate deleterious high-frequency resonant signal parasitizing in the useful signal of the coil circuit. Damping resistors can be used to eliminate the parasitic resonant component of the signal. In this paper, damping effects of the damping resistors on the output signal of Rogowski coil are studied in detail. According to circuit theory, approximate circuit equations of Rogowski coil with lumped parameters in simplification are put forward. Response signal of coil is analyzed and a reasonable method for choosing damping resistance is also presented. When the 50 Ω damping resistance is used, the amplitude of parasitic resonant signal has been damped by 5.7 times in contrast to the situation without any damping resistance. Result of Pspice circuit simulation corresponds to the theoretical calculation result. A standard 10 ns square pulse has been used to calibrate the coil signal before and after the damping resistors soldering on the coil, respectively. Experimental results show that the response time of the coil with magnetic core is 1.1 ns and the parasitic resonance in the coil signal is almost eliminated. The coil can accurately detect high-pulse current at kA range.     

基于罗科夫斯基线圈的脉冲电流的测量

对脉冲电流的测量方法以罗科夫斯基线圈的设计过程进行了阐述，对罗科夫斯基线圈设计过程中的骨架材料以及绕线材料选择的问题，分别进行介绍，同时分析了提高罗科夫斯基线圈互感系数的方法，并通过具体的实验对脉冲电流进行了测量。