微波功率器件测量不确定度评定

本文针对微波功率器件特殊的封装形式，分析了测量夹具引入误差的不可忽略性，进而对测量夹具的误差校准及整个测量系统的校准进行了介绍。文章以微波功率器件测量系统为对象，对整个测量系统的误差来源进行了分析，并以S21为例对测量结果进行了不确定度评定，通过试验数据说明测量夹具误差去除前后对测量结果的影响，对微波功率器件的测量具有可参考的价值。     

林尼克结构干涉测量系统误差分析

在应用林尼克结构干涉测量系统进行测量时,发现系统存在一个近似为二次曲面的测量误差.根据光学干涉系统的测量原理,分别对林尼克结构干涉测量系统的相移器误差、摄像机误差和光学系统误差进行了分析,确定光学系统误差是干涉测量系统的主要误差源,其中显微物镜焦点轴向误差是产生系统测量误差曲面的主要原因.以平面为实验测量样件,应用测量系统对参考光臂显微物镜的不同轴向位置进行了测量,通过分析测量结果验证了焦点轴向误差对系统测量误差的影响,并与理论结果进行了比较.     

提高激光干涉小角度测量系统测量精度及误差修正的研究

本文从理论上对激光小角度测量原理进行深入分析，找出制约测量精度的各种误差源，并提出简单易行有效的误差修正方法。经过实际测试，验证了理论分析的正确性和实际应用的可行性，为激光小角度高精度测量开拓了新的应用领域。     

关节臂式柔性三坐标测量系统的数学模型及误差分析

关节臂式柔性三坐标测量系统是一种新颖的基于旋转关节和转动臂的三坐标测量系统，以角度测量基准取代了长度测量基准，它具有量程大、体积小、重量轻及使用灵活等优点．首先基于Denavit-Hartenberg方法建立了关节臂式柔性三坐标测量系统的理想数学模型和误差模型，并通过几何作图法对模型进行了验证．根据系统的特点和通过对系统中实际存在的影响测量结果的各种误差因素进行了详细分析，为进一步研究系统的误差补偿提供了理论基础．     

wMPS测角不确定度研究

室内空间测量定位系统(wMPS)是一种基于多向定位原理的新型网络式测量系统,为分析系统单站的测角不确定度,建立了角度测量模型,分析了影响系统测角精度的误差源并给出误差的评估方法,利用蒙特卡罗统计法进行了仿真,获得了测角误差的分布.提出一种以多面棱体和平行光管作为调整手段,多齿分度台为角度参考基准的发射站水平角不确定度分...     

自准直仪非线性误差补偿方法的研究

自准直仪角度测量方法基于正切原理,测量灵敏度会随着角度变化而变化,测量原理存在非线性误差。本文针对在自准直仪设计的系统时将测量原理进行线性化,并对非线性误差进行了补偿的方法提出了解决和研究的方法。     

提高激光干涉小角度测量系统测量精度及误差修正的研究

本文从理论上对激光小角度测量原理进行深入分析 ,找出制约测量精度的各种误差源 ,并提出简单易行有效的误差修正方法。经过实际测试 ,验证了理论分析的正确性和实际应用的可行性 ,为激光小角度高精度测量开拓了新的应用领域。     

MAX197在电池检测中测量误差的分析与处理

为了提高电池检测系统中电池测量的精度，对MAXl97模数转换器的主要误差源进行了较详尽的分析与测试，在此基础上提出了提高测量精度的建议和处理方法，其中对误差补偿方法，给出了具体的过程和算法，在实际应用中已有效的将测量误差控制在系统的要求范围内。该建议和处理方法对其它A／D模块的应用具有普遍指导意义。     

机床直行部件运动误差测量的精度分析与对策

分析了经典频域三点法测量直行部件运动误差时所存在的谐波抑制，直线度误差的非周期性、非封闭性以及端点不连续而引起的高阶谐波分量失真等方法误差。为了减少上述方法误差，提出了一种新的时域两点法误差分离技术。首先对传感器拾取的数据做对称延拓，这样可以减小由于所采信号的非封闭性所引起的高阶谐波失真。利用频域三点法得到时域两点法所需要的叠代初值。采用现代控制理论研究了谐波抑制的产生机理。通过合理地配置传感器的安装位置可以优化测量系统的传递特性，减少谐波抑制的发生。该方法既可以得到机床直行部件的运动误差，又可以得到在该机床上加工零件的直线度形状误差，这些测量信息都有助于诊断机床的误差源。通过试验验证了该方法的有效性和精确性。     

产生标准失真源的方法

介绍了失真的测量原理和产生标准失真源的方法；介绍了失真度测量仪自动测试系统，并对测量装置的误差进行了分析。     

Enhanced error estimator based on a nearly equilibrated moving least squares recovery technique for FEM and XFEM

In this paper a new technique aimed to obtain accurate estimates of the error in energy norm using a moving least squares (MLS) recovery-based procedure is presented. In the techniques based on the superconvergent patch recovery (SPR) the continuity of the recovered field is provided by the shape functions of the underlying mesh. We explore the capabilities of a recovery technique based on an MLS fitting, more flexible than SPR techniques as it directly provides continuous interpolated fields without relying on any FE mesh, to obtain estimates of the error in energy norm as an alternative to SPR. In the enhanced MLS proposed in the paper, boundary equilibrium is enforced using a nearest point approach that modifies the MLS functional. Lagrange multipliers are used to impose a nearly exact satisfaction of the internal equilibrium equation. The numerical results indicate the high accuracy of the proposed error.     

Optimal confidence intervals on the variation for operators and gauge in manufacturing process with repeated measurements

It is necessary to measure the attributes of the parts in any manufacturing process. It is also important to monitor measurement system in the manufacturing process because repeated measurements of the attributes include variability as well as target value. This paper considers variabilities due to repeated measurements, operators, and gauge in a measurement system. The measurement system is statistically modeled as a two-factor mixed model with one covariate and interaction. That is, this model employs J operators randomly chosen to conduct measurements on I randomly selected parts from a manufacturing process. In this experiment each operator measures each part K times. This paper aims to provide engineering practitioners with statistically optimal confidence intervals on the variation due to operators and gauge resulted from a measurement system statistically modeled. The optimal confidence intervals are based on a moderate large sample method (MLS) and a generalized p-value method (GEN). The confidence intervals proposed can be useful tools to determine whether a manufacturing process is adequate for monitoring a measurement system.     

Moving least‐square interpolants in the hybrid particle method

The hybrid particle method (HPM) is a particle‐based method for the solution of high‐speed dynamic structural problems. In the current formulation of the HPM, a moving least‐squares (MLS) interpolant is used to compute the derivatives of stress and velocity components. Compared with the use of the MLS interpolant at interior particles, the boundary particles require two additional treatments in order to compute the derivatives accurately. These are the rotation of the local co‐ordinate system and the imposition of boundary constraints, respectively. In this paper, it is first shown that the derivatives found by the MLS interpolant based on a complete polynomial are indifferent to the orientation of the co‐ordinate system. Secondly, it is shown that imposing boundary constraints is equivalent to employing ghost particles with proper values assigned at these particles. The latter can further be viewed as placing the boundary particle in the centre of a neighbourhood that is formed jointly by the original neighbouring particles and the ghost particles. The benefit of providing a symmetric or a full circle of neighbouring points is revealed by examining the error terms generated in approximating the derivatives of a Taylor polynomial by using a linear‐polynomial‐based MLS interpolant. Symmetric boundaries have mostly been treated by using ghost particles in various versions of the available particle methods that are based on the strong form of the conservation equations. In light of the equivalence of the respective treatments of imposing boundary constraints and adding ghost particles, an alternative treatment for symmetry boundaries is proposed that involves imposing only the symmetry boundary constraints for the HPM. Numerical results are presented to demonstrate the validity of the proposed approach for symmetric boundaries in an axisymmetric impact problem. Copyright © 2005 John Wiley & Sons, Ltd.     

基于随动测量系统的步进电机跟踪精度研究

利用ARM控制系统实现齿轮测量仪的两轴随动控制,完成齿轮螺旋线高精度测量.根据步进电机脉冲信号和步距角的线性关系,采用ARM系统输出频率脉冲控制步进电机,由于步进电机只有周期误差而无累积误差,系统能够实现齿轮螺旋线偏差快速、准确测量.与现有系统比较,本系统具有控制精度高、测量速度快、误差精度高的特点,能够实时、动态显示测量误差.     

计量检定校准自动化系统标准接口研究和实现

旨在研究自动化计量软件在检定/校准过程中生成的检定/校准原始记录与现有计量业务管理系统进行数据对接,实现计量业务管理系统与自动化计量软件间的原始记录数据传输,自动生成证书报告。提高工作效率、减轻检定/校准人员的工作负担,减少检定/校准过程中的人为误差与出错,实现数据传输正确性、低碳环保。     

基于评分法的测量系统能力评价

目前所用的测量系统能力评价方法是建立在正态性假设的基础上,如果测量系统误差不满足正态性,运用原来的评价指标在对测量系统能力进行评价的过程中会发生误判。将连续等级概率评分(CRPS)应用到测量系统分析评价当中,通过研究CRPS的相关特性,建立了基于CRPS评分法的测量系统能力评价指标,从而使测量系统误差非正态分布时,对测量系统能力进行评价的过程中不会发生误判。通过案例分析表明,当测量系统误差为正态分布时,运用CRPS和运用传统评价指标给出的评价结果是一致的,同时,CRPS评价方法能够有效实现非正态测量系统误差情形下的测量系统能力评价。     

The meshless hypersingular boundary node method for three-dimensional potential theory and linear elasticity problems

The Boundary Node Method (BNM) represents a coupling between Boundary Integral Equations (BIEs) and Moving Least Squares (MLS) approximants. The main idea here is to retain the dimensionality advantage of the former and the meshless attribute of the latter. The result is a ‘meshfree’ method that decouples the mesh and the interpolation procedures. The BNM has been applied to solve 2-D and 3-D problems in potential theory and linear elasticity. The Hypersingular Boundary Element Method (HBEM) has diverse important applications in areas such as fracture mechanics, wave scattering, error analysis and adaptivity, and to obtain a symmetric Galerkin boundary element formulation. The present work presents a coupling of Hypersingular Boundary Integral Equations (HBIEs) with MLS approximants, to produce a new meshfree method — the Hypersingular Boundary Node Method (HBNM). Numerical results from this new method, for selected 3-D problems in potential theory and in linear elasticity, are presented and discussed in this paper.     

新型零差激光干涉仪测量误差因素分析

介绍了新型零差激光干涉仪的测量原理,实验和理论分析了干涉条纹宽度、激光光强、散斑效应对该激光干涉仪测量误差的影响。结果表明,干涉条纹宽度对振幅测量值影响并不明显,测量误差为0.5%;光强变化引起的振幅测量误差为0.5%,光强较弱会增大测量误差;散斑效应引起的振幅测量误差与透镜参数有关,测量误差为0.4%。该新型零差激光干涉仪可有效降低测振系统对测量环境的要求。     

有效值法交流共模抑制比测量不确定度评定

为解决影响工业现场的数据采集系统精度的共模干扰问题,以波形分析方式研究了交流共模干扰的表现形式,揭示了其同时含有直流偏移叠加交流波动和本底噪声的典型特征。提出以波形有效值幅度进行干扰强度表征,并进行共模抑制比的定量表述;同时使用有效值叠加模型对系统本底噪声的影响予以剔除,提高了共模抑制比的测量精度。基于该方法与流程讨论了其主要的不确定度来源—信号源误差、数据采集系统增益误差、幅度测量误差、幅度分辨力误差以及测量重复性等。进行了测量不确定度分析和评价,结合实例给出了通道共模抑制比的不确定度评价结果,验证了所述方法的实用性与可行性。     

Study on Comparison of Indian Ozonesonde Data with Satellite Data

This paper assesses the quality of ozone data of modified Brewer Mast (MBM) balloonborne ozonesonde and its comparison with MOZAIC Data (version 4), TES data (version 6), UARS MLS (version 5), EOS Aura MLS Data (version 5) and SBUV (version 8.1). The stations that have been used for this analysis: Delhi (28.58N, 77.20E) (Ozonesonde, MOZAIC, TES, UARS MLS, AURA MLS and SBUV), Pune (18.53N, 73.85E) Ozonesonde, UARS MLS, AURA MLS, SBUV and MOZAIC over Bombay presently called Mumbai (20.19N, 72.34E)), Madras presently called Chennai (13N, 80.18E) (MOZAIC and MLS) and Trivandrum (8.48N, 76.95E) (Ozonesonde, UARS MLS, AURA MLS and SBUV). Analysis shows that reasonable amounts of ozonesonde data are of good quality according to WMO criteria (1982) as 70–80 % of data over all the three stations are within the normalization factor of 1.3–0.8 ± (0.05–0.1) although some major changes in instrumentation e.g., new fast running nonreactive Teflon pump, modernized electronics, and smaller case since 1971. Several international intercomparisons carried out in 1970, 1982, 1991 and 1996 respectively, has also been confirmed the same, in spite of fundamental differences among the methods of these intercomparisons as well as ozonesonde types on procedure for sonde preparation, data processing and analysis. The intercomparison of Indian ozonesonde data (1995–1999) is made at troposphere with MOZAIC data (1995–2000) over Delhi and Pune/Mumbai, ozonesonde data (2013–2014) also compare with TES (2013–2014) special observation data over particular station Delhi at troposphere and at stratosphere with UARS MLS (1995–1999), EOS Aura MLS (2005–2014) and SBUV (2005–2013) data at Delhi, Pune and Trivandrum. Tropospheric value of Ozonesonde shows on average 10–20 % higher value than MOZAIC value over Delhi and Pune except in the lower height (<800 hPa) but ozonesonde show 10–15 % higher value than TES over Delhi in the lower height (<800 hPa). The percentage difference between ozonesonde data and UARS MLS data at Delhi, Pune and Trivandrum show variation of ±15 % and ozonesonde data, EOS Aura MLS and SBUV data at Delhi, Pune and Trivandrum show variation of ±45 % in the vertical range of 46 to 10 hPa, where, MLS data show highest accuracy.