测角仪分度误差测量不确定度的评定

测角仪是角度计量常用的仪器。高准确度的测角仪一般作为角度计量标准器使用。由于没有更高准确度的计量标准进行测角仪的检定,根据圆分度闭合即各相邻间隔分度误差的总和为零原理,采用全组合比较或常角对称联系法测量测角仪的分度误差。最新修订的测角仪检定规程(JJG97-2001)规定了1″级测角仪在首次检定或要对度盘进行修正时采用常角排列互比对称联系法,后续检定时采用23面棱体排列互比法检定。本文分别对两方法测量不确定度进行了评定,评定结果其不确定度均优于0．1″。     

如何利用全组合常角法测量圆分度误差

圆分度误差的测量方法有直接测量法和常角测量法。本文介绍了常角法的原理。并通过实例讲解运用常角法测量圆分度器件的测量步骤及其数据处理过程。     

常角法检测圆分度刻划误差谐量失真的研究

经典的常角法测量圆分度件分度误差的分析中没有提及谐量失真的问题。自从高效率的光电检验仪问世以后 ,发现光电定角比相法存在误差的谐量失真 ,经分析是常角法自身引起的。显然 ,误差谐量失真会影响常角法测量圆分度件刻划误差的测量准确性。合理摆置常角 ,用直径全中误差表征刻划误差 ,采用长、中周期误差分项测量等措施可减小谐量失真的影响。     

圆分度测量系列时域联系法的一般模式

一、圆分度误差计算方法的分类概括圆分度误差的计算方法,可将其分为两大部分。第一部分是间隔误差的计算方法,这其中包括绝对比较法、相对比较法(常角法)、全组合法等。用这些方法可给出一定间隔的圓分度误差。第二部分是所谓的联系方法。联系法的作用是将具有不同起测点,不同     

三常角对称联系法的最小二乘解

目前在圆分度误差的检测中所使用的三常角对称联系法,由于其解不是按最小二乘法的原则给出的,因此常称之为简化的对称联系法。它在算法上未能充分体现测量的对称性和利用测量数据给出的信息,它的解对三个测量系列来说不是对称的。本文给出三常角对称联系法的最小二乘解。     

用直径全中误差评定圆光栅的分度误差

本文从测量、采样间隔选取和置信因素Ｋ的确定等方面探讨用标准偏差评定圆光栅分度误差的可能性。     

正多面棱体和多齿分度台角分度误差的互检

排列互比法实现两个圆分度器件互检时操作繁复,工作量大,针对此缺点,本文提出采用排列常角法实现正多面棱体和多齿分度台角分度误差的互检,不需要在每个测回完成后改变两个圆分度器件的相对位置,从而简化了互检过程,缩短了测量时间.详细介绍了互检原理以及操作步骤,实验装置的设计;给出了正多面棱体和多齿分度台角分度误差互检的实验数据,并对测量结果的随机误差进行了分析和计算.最后通过两种实验方法结果的对比,验证了本方法的正确性.     

高精密角度分度测量控制系统的研究

研制并开发了用于角度标定的高精密角度分度装置及其测量控制系统,装置采用永磁直流力矩电机驱动精密轴系主轴的运转来带动分度盘的转动,以圆光栅测量系统检测主轴的转动角度,为了实现角度的零误差分度定位控制,转动角度的分度控制采用了闭环自动控制系统。研究分析了圆光栅测量信号处理中信号细分形成的系统非线性误差对装置分度精度的影响,建立了误差修正模型,通过误差补偿,系统在±5°的角度测量范围内分度控制精度达到±0.2″。     

圆分度角测量检定中的分段内插测量法

圆分度角用排列互比法测量时,一般选用较大的测量间隔角。为了测出大间隔角范围内的小角度偏差,提出了分段内插测量法。由于组成间隔角的两角位置的偏差已由排列互比法测出,因此可作为控制点。通过和小角度陪检工具的连续比较,消减陪检工具角度偏差的影响,得到间隔角范围内的小角度偏差。分段内插测量法是排列互比法的扩展与补充。     

用直径全中误差表征圆分度件的刻划误差

直径误差是衡量线纹圆分度元件分度误差的指标。在评定此项指标的方法上，有采用最或然影响原则，或最大影响原则。本文用实验数据分三种情况说明采用最或然影响原则，即直径全中误差较为合理。     

Measurement of profiles along a circle on two flat surfaces by use of a Fizeau interferometer with no standard

A method for measuring profiles along a circle on a flat surface with no standard is described. For the measurement, two unknown surfaces are placed almost parallel, and the distance between them is measured many times along a circle by rotation of one of the surfaces. Profiles of the two surfaces can be determined from the distance data. In this study the measuring method is explained: The space between two surfaces measured with a Fizeau interferometer. Four measuring experiments are carried out for determining the profile of a precision-grade half-mirror; in each experiment a different ordinary mirror with unknown profile is used as the second mirror. Profiles of the precise mirrors obtained by these experiments agree closely, with deviations of approximately 2 nm. A similar experiment with many concentric circles was carried out with a precise half-mirror and another precise mirror. Although the profiles of many concentric circles were independent of one another, the result shows that the high-frequency component of a whole plane can be estimated.     

标定飞机方向舵角位移的视觉测量法

飞机飞行性能试验前需标定其方向舵的角位移传感器.基于单目视觉,以三个圆心为靶面的基本标志,圆周为辅助标志;用两直线段的交点标明圆心位置.取平行于像面的直径为特征直径,借助它容易从像面椭圆图像提取靶面深度信息,并建立简单、精确的逆透视变换公式.设计了亚像素法处理照片,能精确测出圆心像点位置和特征直径的像长,用来求圆心的世界坐标,得到靶面的平面方程.舵的角位移可用靶面角位移表示.计算机仿真结果,圆心像点位置测量误差小于0.02 pixel,角位移测量误差小于0.005°.靶面与舵轴不平行导致的测量误差能及时修正,可降低对靶面安装的要求,使操作简单.能在现场标定飞机副翼、襟翼,升降舵、方向舵的角位移.     

多边法坐标测量系统中解算方式对测量精度的影响研究

为了研究多边法坐标测量系统中解算方式对测量精度的影响,建立了多边法坐标测量模型,分析了两种目标点坐标解算方式的差异,并针对典型的4台测站多边法坐标测量系统进行了两种解算方式的仿真测量实验。仿真结果表明:预先准确标定系统参数方式能有效提升测量精度,测量精度依次改善了69.5%、64.6%、46.3%。进行了坐标测量精度验证实验,实验结果表明:与同步解算方式相比较,预先准确标定系统参数取模后的3组实验平均测量误差由203.0μm降至23.8μm,且3组实验的测量误差与测量距离的平均相关系数由99.8%降至37.8%,验证了仿真实验结果。     

Compression manometer error due to the nature of its scale

Conclusions A comparison of errors in measuring pressure with a McLeod gauge by means of the linear and square-law scale methods shows that over the entire measurement range the linear scale method is more precise than the square-law scale method, with the exception of one point at which the errors of the two methods are equal.Translated from Izmeritel'naya Tekhnika, No. 10, pp. 33–35, October, 1971.     

Random-phase-shift Fizeau interferometer

A new and potentially cost efficient kind of vibration-tolerant surface measurement interferometer based on the Fizeau-principle is demonstrated. The crucial novelty of this approach is the combination of two optoelectronic sensors: an image sensor with high spatial resolution and an arrangement of photodiodes with high temporal resolution. The photodiodes continuously measure the random-phase-shifts caused by environmental vibrations in three noncollinear points of the test surface. The high spatial resolution sensor takes several "frozen" images of the test surface by using short exposure times. Under the assumption of rigid body movement the continuously measured phase shifts of the three surface points enable the calculation of a virtual plane that is representative for the position and orientation of the whole test surface. For this purpose a new random-phase-shift algorithm had to be developed. The whole system was tested on an optical table without vibration isolation under the influence of random vibrations. The analysis of the root-mean-square (RMS) over ten different measurements shows a measurement repeatability of about 0.004 wave (approximately 2.5 nm for 632.8 nm laser wavelength).     

在多齿分度台上用三位置比较法检定多面棱体的研究

应用数据统计分析方法对在多齿分度台上用三位置比较法及排列互比法了多面棱体工作角偏差进行了比较，运用谐波分析法分析了多齿分度台的分度误差，找到了在一般情况下用三位置比较法检定了多面棱体接近排列比法的结果的理论依据，提出了用多位置比较法检测圆分度器件或仪器的分度误差，提高了工作效率。     

Joint-Angle Measurement Using Accelerometers and Gyroscopes—A Survey

This paper presents an analysis of rigid-body joint-angle measurement based on microelectromechanical-system (MEMS) biaxial accelerometers and uniaxial gyroscopes. In comparison to conventional magnetic and optical joint angular sensors, this new inertial sensing principle has the advantages of flexible installation and true contactless sensing. This paper focuses on the comparison of four different inertial-sensor combination methods that are reported in reference papers and utilizes the theory of rigid-body kinematics to explain and analyze their advantages and weaknesses. Experiments have also been conducted to further verify and strengthen the arguments put forward in the analysis. All experiments in this paper took place on a custom-built rigid-body robot arm model that can be manipulated by hand. Sensor calibration and accelerometer alignment issues are also described, and their details are discussed. The experiment results presented in this paper show significant differences with reference to the achieved angular accuracy for various situations when using the four different sensor combination methods. In some cases, the angular error based on one method is more than 0.04 rad, while that from another method is within $pm$0.005 rad. The noise levels of angular readings from different methods are also experimentally compared and analyzed. The conclusion drawn serves to guide readers toward a suitable method for their particular application.      

Simple wide-range method for angle measurement with a point fiber-optic output

We propose a simple optical method for precise, wide-range angle measurement based on the use of a single-mode optical fiber as a registration scheme output. Because of its micrometric core dimensions, the fiber serves as a point receiver that is highly sensitive to angular displacements of focused laser emission. The method allows the independent photoelectric measurement of both rotation and spatial angles of various optical elements, combining a wide angular dynamic range (from 0 degrees to 360 degrees ) with high accuracy (exceeding 3 arcsec).     

基于抽象工厂模式的机载总线数据通用化处理方法研究

为解决目前TDLAS波长扫描直接吸收法测温领域存在的干扰吸收峰影响温度测量准确性的问题,提出了一种基于吸收光谱线型对称的积分吸光度计算方法,利用中心频率至无干扰吸收峰一侧频率范围的吸光度,根据对称性得到全频域的积分吸光度,以此来排除干扰吸收峰的影响,提高温度测量准确性。选取7185.6 cm^-1和7444.4 cm^-1两条H₂O吸收谱线,利用吸收光谱仿真数据在400~2600 K温度范围内选择8个温度点进行温度仿真计算,同时在实验室环境下搭建一套TDLAS测量系统,在573~1173 K温度范围内进行了管炉测温实验,并将吸收光谱线型对称积分吸光度计算法的测量结果与忽略干扰峰影响的单峰法的测量结果进行对比,结果显示：二者仿真计算温度的平均相对误差分别为1.11%和5.66%,实验测量温度的平均相对误差分别为1.02%和9%,验证了存在干扰吸收峰时根据线型对称性获取积分吸光度进行温度测量的可行性与准确性,为推动TDLAS温度测量技术发展提供了重要借鉴。