利用平行透视投影模型的位姿迭代估计

提出了一种利用平行透视投影模型的高效位姿迭代估计方法来提高单目视觉测量系统的精度和鲁棒性.通过引入齐次坐标表示,避免了现有算法对平行透视投影参考点选择的限制.首先,研究了平行透视投影模型下使用齐次坐标求解目标位姿的方法,阐述了它的几何意义.然后,通过迭代的方式将其应用于一般透视模型下目标位姿的高精度估计.仿真实验结果表明,本文方法提高了基于平行透视投影模型的位姿迭代估计的精度,速度和抗噪性能.实物测量结果表明,本文方法的平移测量精度优于0.1 mm,旋转测量精度优于0.1°,可以满足各种视觉检测系统的要求.另外,使用标志点和图像特征亚像素定位技术还可进一步提高该算法的精度.     

Measuring information signal parameters under additive non-Gaussian correlated noise

Issues related to measuring the information parameters of signals reflected from an object under correlated additive non-Gaussian noise are considered. It is shown that in the presence of correlated non-Gaussian noise, increasing the correlation coefficient increases the generalized signal/noise ratio, which, in turn, improves the measurement accuracy of signal parameters. The obtained dependences confirm that the measurement error of signal information parameters is affected not only by the generalized signal/noise ratio, but also by accounting for the non-Gaussian nature of the additive noise, which leads to a significant improvement in the measurement accuracy of these parameters.     

光纤传感测量液体折射率的方法研究

根据菲涅耳公式,推导出了溶液折射率和线偏振光反射率的关系,分别测定不同待测溶液折射率下线偏振光p分量和s分量的反射率,并与理论结果进行比较。实验用阿贝折射仪测定不同浓度下Na_2CO_3溶液的折射率;立足于光纤传感系统,以棱镜为敏感元器件、光为测量媒介,在敏感角入射的情况下,采用光电探测器对偏振光信号进行探测,经光电变换后利用信号调理电路实现信号采集,模数转换后运用单片机实现信息的处理,测定不同浓度溶液的反射率,与理论结果进行比较。结果表明,该方法在实时测量液体折射率的灵敏度、精度方面有较大改善。     

基于核熵成分分析的光谱重建算法研究

对基于核熵成分分析的光谱反射率重建方法进行了研究,分别采用主成分分析方法和核主成分分析方法构建光谱反射率重建算法进行颜色重建研究,并与基于核熵成分分析算法的光谱反射率进行比较。实验结果表明,基于核熵成分分析的光谱重建算法在色度精度和光谱精度上均优于主成分分析和核主成分分析,对物体表面颜色的真实重建具有一定的应用价值。     

一种高温物体温度在线测量仪

本文介绍了一种利用遮蔽板作为标准噪声辐射源、以8031单征机为核心实现的实时在线测量静止及慢速运动的高温物体的比辐射率及温度的系统,系统由光学接收系统、信号放大与处理系统及显示系统组成。文中还介绍了该系统的原理与结构,讨论了其中的技术难点及其相应的解决方法,分析了系统工作波长的选择、扇形板关闭时P1、开启时的P2及标准噪声辐射源的辐射能P3的测量精度对比辐射率及温度测量精度的影响。     

Image analyser measurements of coal reflectance

The application of an image analyser to the rapid measurement of coal reflectance histograms is described. The ability of an image analyser to utilize a two-dimensional image allows the coal only to be represented in the reflectance histogram, with contribution from the resin used in particulate block specimens eliminated. While the accuracy of reflectance measurement with an image analyser is not as great as can be obtained with a spot photometer system, sufficient accuracy is obtainable for rank determination.     

Velocity vector (3D) measurement for spherical objects using an electro-optical device

The present paper describes a procedure to measure the velocity vector (3D) of a spherical object using an electro-optical device configured as a single large detection area optical barrier. The proposed procedure allows a measurement accuracy up to 0.1% in some cases and presents several advantages in relation to other measurement procedures like image processing, doppler-radar and some other electro-optical devices. The procedure is independent of the relative position of the measurement device in relation to the object trajectory. The fact of using a single optical barrier reduces the space required in the movement direction and increase the cases where the device can be used. A prototype has been built and tested.     

非偏振分光镜对干涉式椭偏仪测量精度的影响

提出了一种新型激光外差干涉椭偏测量术用于实现纳米级精度的薄膜厚度测量。采用偏振光p和s分量透射比、反射比、反射相移、透射相移共同表征非偏振分光镜(NPBS)的退偏效应,建立了相应的误差模型,从而研究了多层介质膜NPBS的退偏效应和方位角对椭偏参数误差的影响。研究结果表明,由环境温度、入射角和光束偏振态的变化引起的NPBS退偏参数的漂移对椭偏测量精度影响很大,且无法通过标定来降低。为实现纳米级测量精度,NPBS的对准误差需要控制在0.1°以内。相对而言,用于合光的NPBS方位角误差对测量精度影响较大,NPBS所导致的膜厚测量总误差约为1.8～2.5nm,说明NPBS是马赫曾德尔干涉式椭偏仪的一个不可忽视的误差源。     

Correlative velocity measurement of narrow and broad objects

The design of sensors for correlative velocity measurement has to take into account the shape of the measurement object. In configurations where narrow objects pass in front of broad detectors, transversal variations of the object position may cause systematic errors of measurement. In contrast, such errors do not occur when measuring at broad webs. The phenomenon can be mathematically described by two-dimensional calculation of the signal correlation, considering the stationarity properties of the pattern observed by the sensor. The consequences on the design of optical correlation sensors concern the accuracy of detector alignment as well as the configuration of the object illumination.     

极限电流型氧化锆氧分析仪的设计

本研究采用极限电流型氧传感器为敏感部件,以PIC16F877A单片机为核心控制器,设计了一种氧分析仪,详细介绍了极限电流型氧传感器的工作原理及饱和电流与氧气浓度公式的获得,给出了信号检测、LCD显示等硬件电路和系统软件的设计方法,并使用自校验功能和格罗布斯准则对K值的漂移和测量时产生的粗大误差进行处理。经测试,设计的氧分析仪测氧浓度范围为0.1%～45.0%时,准确度可达±0.5%F.S。     

A novel mathematic model of LASER Doppler velocimeter for the velocity measurement of solid-state surface

The interference fringe model and the principle of light scattering are applied to establish a mathematic model of LASER Doppler velocimeter (LDV) to analyze the Doppler signal of the solid-state surface. The reflectance and the average size of particles are used to represent the characteristic of the solid-state surface. The relationship among the characteristics of the solid-state surface, the signal intensity and the measurement accuracy is given by numerical simulations and experiments. Results show that Doppler signal is a cosine signal superposed on a Gaussian basement; the relative error of the system is less than 0.5% when the average size of particles is smaller than 140 μm, but the relative error fluctuates strongly and the measurement is not accurate when the average size of particles is larger than 140 μm. LDV will measure the speed of a moving solid-state surface precisely if the surface roughness is within the range.     

真空紫外-极紫外反射率计控制与数据采集系统

针对自行研制的真空紫外-极紫外(VUV–EUV)波段反射率计运行需要,基于LabVIEW软件构建了该反射率计控制和数据采集系统。详细介绍该系统的组成和主要硬件单元模块的控制流程与方法,并给出准直调试程序和反射率数据采集程序的架构、用户界面和数据采集方法。提出的新数据采集算法有效提高了弱信号条件下反射率测量的可靠性。利用该控制与数据采集系统,对Si基板开展了准直校准与反射率测量实验。结果表明,在7.5°～87.5°范围内直通光电流信号为20 pA时仍能获得可靠的反射率,且基于入射光监测方法的反射率测量实验结果与理论计算相符更好。除在布儒斯特角附近信号电流小于本底电流0.7 pA时,反射率重复测量误差优于1.6%。     

Dynamic junction temperature measurement for high power light emitting diodes

Junction temperature of high power light emitting diodes (LEDs), which is crucial for the thermal management of solid-state lighting, needs to be measured accurately. In this paper, a dynamic junction temperature measurement system for LEDs was proposed and the calibration including instrument calibration and factor K calibration were presented. The influence of the fast switch time in dynamic junction temperature test was analyzed and measurement errors caused by sampling delay were quantified. To prove the accuracy of the present system, comparison experiment was conducted. It shows a good agreement between the experimental data and reference value. Experiments also show that the measurement accuracy of the instrument can be up to 0.1?°C, and the standard error of temperature measurement can be controlled within 1%.     

The use of RuO<Subscript>2</Subscript> resistors as broadband low-temperature radiation sensors

The possibility of using commercial RuO₂ planar resistors as low-temperature radiation sensors was investigated. At temperatures of 0.08–0.1 K, their sensitivity to blackbody radiation at temperatures of 5–40 K was about 2–3 pW. The radiation absorption coefficient was <10%. The response is a linear function of the radiation power, thus indicating that the detector band is no narrower than 0.5–2.5 THz. The rise time of an output signal without feedback-assisted temperature stabilization was ~12 s owing to an unexpectedly high thermal capacity of the resistor.     

基于偏转法的物体三维形貌测量

基于数字散斑干涉测量技术,组建一套基于偏转法的物体三维形貌测量系统。首先,通过精密旋转平台使被测物体偏转微小角度,在其表面引入包含该物体形貌信息的弯曲干涉条纹。然后由散斑干涉条纹图提取其相位分布,对滤波后的包裹相位图进行相位解包裹运算,得到相位的真实分布图。最后根据相位分布与物面高度的关系求解出被测物体的高度信息。实验结果表明采用偏转法的散斑干涉技术可以实现物体三维形貌测量,具有测量精度较高、易于实现等优点。     

基于空气轴承的高精度圆度测量系统设计

利用高精度空气静压轴承和非接触位移传感器,设计了一套圆度测量系统,可以实现外圆柱面圆度的精密测量。该系统的圆度测量结果与英国TaylorHobson公司的高精度圆度仪测量结果对比表明,可以达到0．1μm以下的测量精度。多次测量证明,该系统测量结果重复性好、可信性高。     

基于STM32F103的旋转角度测量装置设计

设计一种基于增量式编码器和STM32F103系列芯片的角度测量仪。该装置与被测物件按一定传动比固定安装,系统自动测出传动比并存储,以免断电数据丢失。被测物件每转动一周,光电传感器触发一个零位信号,编码器输出A、B两相方波信号,STM32F103芯片接收到编码器的脉冲信号后根据算法求出对应的角度值,经串口在上位机界面实时显示并分析实验数据,得到不同传动比下的角度测量精度。     

用于材料反射率测量的共轭反射计设计与分析

为了研究激光辐照过程中材料的耦合特性及耦合特性随温度的变化规律,设计了一套主体为半椭球壳体,可用于激光辐照过程中材料反射率在线测量的共轭反射计实验装置,研制完成的初样其主体内壁在可见-长波红外光谱范围内镜面反射率优于70%。介绍了测量原理和测试系统的设计方案,采用光线追迹模拟方法研究了主体部分的设计参数,分析了开孔位置、入射方向、光斑尺寸、收集孔径以及内壁反射特性对测量收集效率的影响。结果表明:在设计指标下选用探测光束直径为Φ10 mm、收集孔径为Φ38.1 mm时,收集效率可达到完全收集的97.8%,满足测量要求。另外,用短波激光测量内表面光洁度有更高要求;理想面型条件下,限定范围内的收集效率主要由内壁镜面反射率决定;因此,半椭球内壁的面型、光洁度、反射率及其均匀性是影响测量精度的主要因素。     

标准漫反射板绝对反射比因子测量装置

分析和研究了测量绝对反射比因子的原理,设计、制作了一套可以测量光源入射照度和反射辐亮度的比辐射计和一套45°/0°漫反射板绝对反射比因子测量装置。首先,使用比辐射计测量光源的入射照度和反射辐亮度,给出漫反射板绝对反射比因子的计算公式;然后,根据推导公式中辐射亮度由测量比辐射计的光阑面积决定,提出一种新的光学方法来精确测量光阑面积,从而提高测量精度。最后,介绍了测量装置的设计和其它部件的制作过程。采用该装置实验测量了安徽光学精密机械研究所研制的标准漫反射板在633～960nm的绝对反射比因子,得到的装置的测量不确定度为0.19%。实验结果表明,该测量装置测量方法简单、精度高,可以满足反射比因子的测量要求。     

A high-temperature accessory for measurements of the spectral characteristics of thermoluminescence

A high-temperature accessory for a commercial fluorescence spectrometer, which allows performing luminescent studies of solid samples in the range up to 773 K, is described. The modes of linear heating with rates of 0.1–10 K/s, temperature control with an accuracy of <0.5 K, and an arbitrary temperaturetime profile were realized. The operation of a Perkin Elmer LS55 spectrometer at high temperatures was demonstrated by the example of investigating the spectral and kinetic regularities of thermoluminescence in hexagonal boron nitride using the developed module.