科技新成果信息

WSF颜色测量系统该仪器是配有微机和测色软件的光、机、电、计算机一体化的测色仪器。可测物体的透过率和光谱反射率,可直接测出标志物体颜色的三刺激值、色品坐标、三颜色空间明度值、色度指数,可指出白、黄色褪色牢度、沾色牢度及色差、黄度差等。     

高清激光显示中的色彩复现系统

利用60吋全固态激光电视样机,建立了原有的电视色度信号向激光电视色度信号转换的模型。根据激光显示的特点,推导出以三色激光(红:660nm,绿:532nm,蓝:457nm)为三基色的激光电视颜色系统与荧光粉电视三基颜色系统的矩阵转换关系。利用解码模块、现场可编程门阵列(FPGA)色域转换模块和编码模块搭建了激光三基色系统和普通电视三基色系统的色域转换电路,分析了电路中各个模块的作用及整个电路的工作过程,实现了对高清视频信号的色域转换。对比了不同颜色在转换后的激光电视上与荧光粉电视上的显示效果,对11个特征颜色的测量显示,其色域转换误差小于9.8%。实验取得了很好的色域转换效果,成功地验证了高清激光电视的色彩复现能力。     

UV365分光光度计与微机联机测色系统

UV365分光光度计是一台双单色仪研究型仪器。本文介绍了分光光度计与微机联机,组成的高精度颜色测量系统。详细讨论了系统接口的硬件和软件设计,以及色度参数处理。该系統能测量样品在A、B、C和D_(65)等标准照明体下的色度坐标和四种颜色空间中的色度参数。     

脉冲多通道快速分光显微色度仪

本文开发了一种用于颜色产品微面积精细颜色测量、采用脉冲氙灯光源、光纤环形照明、全息平场凹面光栅型脉冲多通道快速分光显微色度仪。该仪器结构简单、色分辩率高、色品坐标精度为０．００２、最小分辨线视场为０．０１ｍｍ，测量光谱范围为可见区、光谱分辨率为１０ｎｍ、测量时间间隔短、能进行较暗物体和荧光物体的微面积精细颜色测量，并能给出各种标准照明体和各种色度系统下的色度参数     

光纤型脉冲多通道快速分光颜色测量仪

本文开发了一种采用脉冲氙灯光源照明、多元陈列光纤做为多通道接收器的光纤型脉冲多通道快速分光颜色测量仪。该仪器的色分辨率高、动态范围大、色品坐标精度为０．００２、测量光谱范围３８０ｎｍ－７８０ｎｍ、光谱分辨为１０ｎｍ、测量时间为几个ｍｓ、测量时间间隔小于５ｓ、能测量较暗物体的颜色，并能给出各种标准照明体和各种色度系统下的色度参数。如果将照明光源换以紫外激发光源或待测光源，就能进行荧光物体和颜色的脉冲     

计算机彩色图像再现系统中的颜色矫正研究

随着网络、多媒体技术的发展,计算机彩色图像再现系统中交互界面上颜色的高保真再现变得日益重要.本文结合敦煌壁画的计算机存储与管理工作,研究了从彩色扫描仪到计算机CRT显示器的颜色矫正问题,克服人为因素的影响,提出了一种新的CRT显示器色度预测方法和一种多约束因子颜色矫正还原模型.采用CIE1976(L·a·b·)匀色空间的色差函数ΔΕ进行矫正效果评价.结果表明,本文提出的颜色矫正还原模型能对扫描、显示等环节中各种因素所造成的颜色失真实现客观、定量、一次性的总体矫正,可以广泛应用到计算机彩色图像再现系统中.     

基于概率神经网络的尿样颜色识别

基于概率神经网络,提出一种与尿液反应后尿试纸的颜色识别方法。针对颜色色空间转换的非线性复杂关系,获取标准阈值颜色色度值,进行归一化处理后,建立基于概率神经网络的尿样颜色识别模型。实验结果表明,用概率神经网络进行尿样颜色识别是可行而有效的。与颜色色差评价方法作比较,该方法无须进行色空间转换,只利用设备原有RGB颜色空间的RGB值即可实现,更易于操作。     

CIE1976(L*a*b*)匀色空间颜色变量特性研究

CIE1976(L^*a^*b^*)颜色空间是较理想的匀色空间之一.为了使它获得更广泛合理的应用,人们继续对其进行探讨和改进.本研究利用心理物理评价实验,对该空间的诸变量特性进行了研究.     

用彩色CCD相机测量发光二极管显示屏的色度

提出了一种高精度色度计和彩色CCD相机相结合快速测量发光二极管(LED)显示像素的亮度和色度的方法.首先,用彩色CCD相机测量LED显示像素,通过图像处理提取每个LED显示像素点在RGB颜色空间中的亮度值和色度值.然后,建立RGB颜色空间和CIE 19 31XYZ颜色空间的多通道自适应矩阵,并使用色度计对部分LED显示像素点进行精确测量,基于精确测量值和对应的RGB值计算出自适应矩阵.最后,通过自适应矩阵计算出所有LED显示像素的亮度和色度值.实验结果表明:自适应矩阵大小合适的情况下,该方法计算出的数据与色度计测量数据之间的色差值△E＜1,在人眼视觉中的颜色差异轻微,可快速、精确地采集LED显示像素的亮度和色度值,实现LED显示屏的高精度亮度、色度校正,从而大幅提高LED显示屏的显示效果.     

一种新型白平衡仪的研究

本文介绍一种新一代的白平衡仪。它用二组色度型探测器分别测量彩色电视机亮暗白场的三刺激值Ｘｒ、Ｙ、Ｚ得到色品坐标和亮度;并利用刺激值Ｘｒ、Ｙ、Ｚ与红绿蓝三色光强Ｒ、Ｇ、Ｂ间的关系,得到三角光的相对强度。     

手持式激光光色性能测量系统实现及误差分析

鉴于激光波长相对固定的特性,采用一种新的测量激光光色性能测量方法,设计出基于单片机的手持式高精度激光光色性能测量系统。该系统可实现不同波长激光光色性能测量,通过系统初始化时波长输入来提取相应光谱三刺激值,而后进行参数计算。对测量系统进行了实验误差分析,由系统验证结果及误差分析表明,该系统可实现低成本制作,所述测量原理能完成对色空间坐标、光照度、色温等光色性能参数的高精度测量。     

Development of the LED measurement system of chromaticity coordinates correction

In this paper, we propose a procedure to adjust the chromaticity coordinates by using a few samples of the color measurement coordinate to do the error correction and choose the correction method of minimum color error difference average to be the procedure of measuring instruments, and to construct an efficient and predictable calibration procedure. This research adopts some engineering statistics methods, such as median and average methods, and corrects the experiments to obtain the chromaticity coordinates. The four calibration methods that we designed lower the average value of the color errors as 0.034. Moreover, the minimum average value of errors in the X-axis could be revised to 6.3% while the minimum average value of errors in the Y-axis 8.8%. The accuracy of best calibrated chromaticity coordinates could achieve to the percentage 71.1%.     

The study of chip characteristics and tool wear in milling of SKD61 mold steel

In recent years, many machining applications have used dry cutting for high-speed cutting, for which, tool life prediction and research are important issues. In this study, a tungsten carbide tool cutting steel SKD61 was used, and the actual value of the chip shooting and the wear of the flank were determined using an industrial camera. The chip type and chip color are also discussed. After color calibration and chromaticity conversion, the model was trained through the neural network and the results were predicted. The tool wear curve and the theoretical curve were found to be closely related, and the chip color changed regularly. In the CIE XY chromaticity coordinate value, when the initial cutting was observed, the chip chromaticity coordinate point range was small, but as the wear amount increased, the chip chromaticity coordinate point range expanded gradually. The tool wear prediction established in this study was determined from the experimental results. The maximum errors of the test and verification were 0.031 mm and 0.022 mm. After calculation, the mean absolute percentage error (MAPE) was within 3 % and the accuracy level is MAPE is less than 10 %, so it has a high accurate prediction ability. Established tool wear predictions are also provided.

     

基于Cortex-M3的快速发光二极管光电参数测量系统

针对发光二极管（LED）分选设备对光电参数测量系统的需求,研制了一种基于Cortex-M3（以下简称M3）的快速LED光电参数（包括光参数和电参数两部分）测量系统。该系统分为光参数检测模块（自制光谱仪）、电参数测量模块及显示模块等3部分。光参数检测模块采用M3作为主处理器,对测量获得的光谱数据进行计算,进而得出实测的LED光参数,并将光参数传递给同样以M3为主处理器的电参数测量模块。利用该系统架构,有效提高了LED参数测量的速度和性能。最后,在脱离LED分选机械控制的前提下,利用研制的LED光电参数测量系统进行了LED的实际快速测量。结果显示：电参数测量周期小于31 ms,光参数测量周期可小至10 ms,色坐标一致性误差小于0.002 5%。     

光谱扫描间隔对节能光源色度测试的影响研究

研究了光谱扫描间隔对节能照明光源色度测试及合格性判断的影响.实验采用积分球-光谱仪测试系统,分别以1nm和5nm两种光谱扫描间隔测量节能灯样品光谱、色温、显色指数、色坐标等参数.实验结果发现:1nm、5nm采样条件下光源光谱功率在610nm附近峰值相差最为显著;1nm扫描间隔所测色温值均高于5nm间隔所测值,显色指数均...     

宽谱段、动态局部高分辨离轴主动反射变焦系统

为了实现无遮拦、宽谱段、动态的局部高分辨成像,设计了一种局部高分辨率的离轴主动反射变焦系统。该系统将离轴主动反射式变焦理论和局部动态高分辨率成像理论相结合,实现了宽谱段范围内不同焦距处的动态局部高分辨成像。采用曲率半径可变的变形镜实现变焦,避免了传统机械变焦中复杂的机械运动控制,减轻了系统体积和重量并有效地保证了系统的宽谱段和大视场;通过对变形镜面形的控制,在不同焦距处实现了全视场内任意感兴趣区域的局部高分辨成像,降低了数据传输量;而采用无色差的反射式系统则克服了传统透射式及折反射式系统只能实现单色局部高分辨成像的缺点。经过优化设计,系统在可见光范围内成像,焦距f′为75 mm(视场角FOV为x:0°~0.5°,y:3°~10°)~150mm(FOV为x:0°~0.5°,y:1.7°~5°),F/#为7~14。理论和仿真分析表明,系统在各焦距处感兴趣区域内的成像质量均可达到衍射极限,实现了全视场内任意区域动态局部高分辨的成像效果。     

发光二极管用于光度测量的表征和颜色增强

发光二极管(LED)光源和发光体的光度测量表征的新标准要求光度和色度量的测量值.本文研究了不同光谱和不同色温下的一些LED光源在光度计和色度应用中的表现.这项研究依赖于这些不同类型的LED混合光谱来增强显色指数(CRI),以尽可能接近标准源.LED光源表征需要一些光度和色度的评价数量,如光通量(?),色度坐标(x,y)和(u′,v′),相关色温(CCT)和显色指数(CRI).     

Uncertainty assessment of a prototype of multilateration coordinate measurement system

Large Volume Metrology is essential to many high value industries to go towards the factory of the future, but also to many science facilities for fine alignment of large structures. In this context, we have developed a multilateration coordinate measurement system, traceable to SI metre, and suitable for outdoor measurements or industrial environments. It is based on a high accuracy absolute distance meter developed in-house and shared between several measurement heads by fibre-optic links. Thus, from these measurement stations, multiple distance measurements of several positions of a target can be performed. At the end, coordinates of the heads and of the different target locations are determined using a multilateration algorithm with self-calibration.In this paper, the uncertainty of this multilateration coordinate measurement system is determined with a consistent metrological approach. First, 13 different sources of errors are listed and quantified. Then, thanks to Monte Carlo simulations, the standard uncertainty on a single absolute distance measurement is assessed to 4.7 μm. This includes the uncertainty contribution of the telemetric system itself, but also the contributions of the mechanical designs of the measurement heads and the target. Lastly, measurements of three-dimensional coordinates of target positions are performed in a control environment, then in a large workshop without temperature control: these measurements validate the uncertainty assessment of the system.     

Acquisition of point cloud in CT image space to improve accuracy of surface registration: Application to neurosurgical navigation system

Journal of Mechanical Science and Technology - One important technique of surgical navigation is surface registration that matches coordinates in two different spaces. We proposed a novel method to...