Optical techniques for on-line measurement of surface topography

Optical techniques have great potential for non-destructive and on-line measurements of surface roughness during manufacturing. This paper reviews the state-of-the-art in a number of optical techniques including specular reflectance, total integrated scatter, diffuseness, angular scattering distributions, speckle, ellipsometry, and interferometry. The distinction is drawn between the more quantitative but slower profiling techniques and less quantitative, parametric techniques, which are faster and hence more useful for high-speed monitoring of surfaces. Overall, no currently available technique combines accuracy and speed and is therefore suitable as an on-line metrological tool for roughness measurement of engineering surfaces. Speckle techniques hold perhaps the greatest potential as accurate, high-speed metrological tools     

Emerging chemical sensor technologies for use in on-line applications

Advances in instrumentation and process control capabilities are being driven by the increased sensitivity of analytical chemistry methods, the commoditization and ruggedization of instruments and associated electronics, and changing consumer concerns and expectations, as well as government regulations. The emergence of biotechnology methods for the detection of contaminants, and the miniaturization and ruggedization of more standard analytical instruments based on mass spectrometry and infrared spectroscopy will be discussed as related to on-line process monitoring.     

表面组装在线检测中模板匹配的研究

作为重要的在线检测技术,自动光学检测是保障表面组装质量的主要手段。深入分析自动光学检测中的关键技术——模板匹配,应用实数编码的改进遗传算法进行模板匹配寻优。试验表明该方法的匹配速度和匹配精度均较为理想,该方法是可行的。     

Attitude-sensor-aided in-process registration of multi-view surface measurement

A novel method for in-process registration of 3D point clouds scanned from different views is presented. A miniature attitude sensor, which can output its pitch, roll and yaw angles in real-time, is mounted on the scanner. The relative pose between the attitude sensor and the scanner is calibrated in advance by a simple yet effective algorithm. When the scanner is moved from one standpoint to another in a measuring process, the real-time readings of the attitude sensor is utilized to compute the rotation movement of the scanner. After applying the rotation transformation to the current point dataset, the translation movement is efficiently determined by exploiting the normal vector constraint between the correspondence points. The rigid transformation obtained fully automatically can serve as a qualified initial estimate for further fine registration. Experiments demonstrate the applicability of the proposed method.     

光学薄膜表面微细缺陷在线检测方法研究

为了对光学薄膜进行精密光学检测,需要采用数个具有高解析度的线阵CCD相机进行光学薄膜缺陷图像的同步采集。基于计算机视觉的理论,提出了一种有效的自动质量监测方案,实现对光学薄膜表面微细缺陷项目的检测,并根据检测结果驱动打标机对光学薄膜缺陷进行自动标识和定位,该方法具有高精度、实时、在线和非接触的显著优势。探索性实验结果表明,采用该方法可获得光学薄膜表面缺陷的清晰图像,缺陷的细节能够得到很好的展现,并且能够完成缺陷特征的提取与识别。     

A mobile complex for on-line studying water areas and surface atmosphere

The complex is intended to perform continuous measurements of concentrations of chlorophyll a and dissolved organic substances by the laser induced fluorescence method, evaluate a state of the photosynthetic system of phytoplankton cells, and record readings of the CO₂ gas analyzer, sensors of sea water saltiness, pH, and temperature, and solar illumination meter. The mobility of the complex ensures a possibility of its operation on different ships and under stationary conditions. The configuration of the complex can be promptly changed for solving the current problem by promptly adding or replacing separate devices and sensors of the complex, as well as the software integrating all devices and data into the system. It is possible to use standard, vibration-resistant laboratory equipment, since the housing of the designed device ensures protection against the marine environment. Results of in-situ measurements performed in the Peter the Great Gulf (Sea of Japan) in 2012 are given.     

光学元件表面的数字全息在线检测

针对光学元件表面质量在线检测的特点,设计了基于数字全息的三维再现检测系统.该系统采用离轴光路,避开了被测元件的光轴,在数字全息再现过程中应用倾斜相差补偿技术去除了由于离轴检测引入的倾斜相位畸变.在检测过程中,利用围绕光轴旋转被测元件的方法来改变入射照明光方向矢量和相应的观察方向,实现了多照明矢量合成孔径技术的应用,扩展了系统的检测距离,提高了系统分辨率.同时,多照明角度下检测数据的叠加,还有效地抑制了检测过程中出现的散斑噪声对结果准确度的影响.通过对分辨率板、高精度玻璃反射镜的检测实验,验证了该系统在光学元件表面检测中的作用.当记录距离为40 cm时,其分辨率能够达到10 μm,满足光学元件表面检测的需要.     

大型薄板曲面件在机测量技术的研究

为解决大型钣金曲面件因体积大、易变形、装卸不便等给测量带来的困难,提出了一种曲面测量的新方法即在机原位测量方法,并将其成功应用于某大型曲面件喷丸成形机上,实现了大型喷丸成形曲面件的在机测量.该测量方法使测量与加工采用同一基准,消除了因基准不重合带来的测量误差,提高了测量精度:避免了工件的重复装夹,提高了测量效率.采用曲线曲面匹配和误差分离技术对测量数据进行处理,完成了对被测件的评价.大型喷丸成形曲面件在机原位测量系统的研制成功验证了所提出的测量方法是可行的.     

蓄电池在线智能监测仪的设计

蓄电池作为电力系统的后备电源，其维护工作对保证电力系统的安全运行具有重要意义。对蓄电池实施在线监测并及时发现失效电池，是蓄电池维护工作的重中之重。文中介绍一种以单片机ADuC831为核心的新型蓄电池在线智能监测仪，能实现对蓄电池无论在浮充状态还是充、放电动态过程中的状态检测。着重介绍其软硬件设计方法。     

螺纹的重复切削

在使用配有ＮＵＭ数控系统的机床进行螺纹切削时 ,可以随时中断螺纹切削 ,并且从卡盘上取下工件进行其它的处理 ,例如测量、淬火等。然后重新将工件安装在卡盘上继续进行螺纹加工 (并且可使用与粗加工循环不同的主轴速度 )。当工件重新安装后 ,其轴向位置及角度位置可能与以前的位置不同 ,因此必须使用“螺纹重复切削循环”(恢复螺纹切削 )来示教螺纹的新位置。通过调用Ｘｐｏｓｔｅａｃｈｉｎ(主轴角度定位用Ｓｐｏｓｔｅａｃｈｉｎ ,主轴 1对应Ｅ90 10 0 )手动地执行螺纹位置的示教功能来确定粗加工螺纹的刀具位置及轴向位置 (或在Ｘ轴方…     

Application of the contact potential difference technique for on-line rubbing surface monitoring (review)

The Kelvin technique for measuring contact potential differences has been adapted for continuous non-destructive monitoring of changes in the electron work function of a rubbing surface. The method can be used to investigate tribological materials for a wide range of conditions, including changes in load, sliding speed, and environment, with or without lubrication. It relies on the sensitivity of the work function to the various events which accompany friction, e.g., plastic deformation, creation of new surface material, adsorption, oxidation, phase changes and redistribution of alloy components. At present, this is the only method which is sensitive to both surface and near-surface defects and permits study of one of the two interacting surfaces during sliding. Current work emphasizes two aspects of sliding behavior: (1) critical points with respect to changes in normal load, with relevance to materials selection and optimization, and (2) the kinetics of friction processes, including periodic changes which may be related to those in fatigue. This revised version was published online in June 2006 with corrections to the Cover Date.     

Caveat on the use of alloys for surface replication

Some replicas of plant cell surfaces produced by platinum/palladium evaporation were of very poor quality. Scanning electron microscope X-ray microanalysis showed that only Pd was evaporated from the Pt/Pd alloy, leaving the Pt on, or alloyed with, the tungsten filament used for evaporation.     

基于分支限界的三维曲面全局配准方法

在三维测量中常需要将测量点云数据与已知曲面模型进行配准。采用隐式函数建立点云数据到曲面模型的距离场,进而进行非线性优化求解可以有效提升配准效率。然而由于点到曲面的近似距离及刚性变换的约束,其误差函数呈现非凸性而导致迭代极易陷入局部最优。为实现全局配准,提出了一种利用分支限界算法搜索点到曲面近似距离平方和误差函数最小化变换参数的方法。通过确定刚体变换参数空间中误差函数的上下界限加快搜索,并结合一种等效距离公式的LevenbergMarquardt算法优化的局部配准方法加速收敛并保证配准精度。三维模型的配准实验与分析验证了本文全局配准方法的有效性。     

加工中心在线测量系统在自由曲面COPY加工中的应用研究

在没有三坐标测量机等不具备逆向设计条件的情况下,通过编制用户宏指令对在线测量系统进行控制,收集和处理模型曲面测量数据,则可以实现类似三坐标测量机自动扫描曲面测量和实现仿形加工的功能.阐述了COPY加工的原理、程序的编制方法、加工误差分析及为保证加工精度应采取的措施.     

On the use of a modular system for microtopographical surface measurement

Conventional apparatuses for roughness measurement have one important shortcoming. Being built around a microprocessor they do not allow any access to the software and permit only a choice among the classical parameters selected by the manufacturer. The user cannot add any new program allowing a continuous extension of the capacity. The system presented here permits both this continuous extension and the use of a large range of microcomputers and devices.     

阳极溶出伏安法在地表水重金属在线监测中的应用

我国的地表水安全形势已经非常严峻,尤其是重金属污染事件的频发。引起了有关部门对饮用水源安全的高度重视,环保部门也加强了对饮用水源的监测力度。在对地表水重金属的分析过程中,地表水标准中对重金属的监测方法不能满足各种重金属项目监测方法的要求,实验以Jaroslav Heyrovsky在1959年发明的阳极溶出伏安法在对地表水进行重金属项目的实时监测进行探讨。     

Spline-based image-to-volume registration for three-dimensional electron microscopy

This paper presents an algorithm based on a continuous framework for a posteriori angular and translational assignment in three-dimensional electron microscopy (3DEM) of single particles. Our algorithm can be used advantageously to refine the assignment of standard quantized-parameter methods by registering the images to a reference 3D particle model. We achieve the registration by employing a gradient-based iterative minimization of a least-squares measure of dissimilarity between an image and a projection of the volume in the Fourier transform (FT) domain. We compute the FT of the projection using the central-slice theorem (CST). To compute the gradient accurately, we take advantage of a cubic B-spline model of the data in the frequency domain. To improve the robustness of the algorithm, we weight the cost function in the FT domain and apply a "mixed" strategy for the assignment based on the minimum value of the cost function at registration for several different initializations. We validate our algorithm in a fully controlled simulation environment. We show that the mixed strategy improves the assignment accuracy; on our data, the quality of the angular and translational assignment was better than 2 voxel (i.e., 6.54 angstroms). We also test the performance of our algorithm on real EM data. We conclude that our algorithm outperforms a standard projection-matching refinement in terms of both consistency of 3D reconstructions and speed.     

Fast measuring with microcomputers for on-line weighing

Output signals from weighing systems suffer from the finite time lag of the scale and other error signals caused by vertical movements of the load. Efficient digital filters were designed and tested to eliminate these error signals with respect to low computing and programming expenditure. The main tests were made with the weighing of freight trains in motion up to velocities of 120 km/h.     

支持在线重组的产品信息统一表达

研究了实现产品信息统一表达的思想及方法，针对产品信息的两种标准即STEP产品数据标准和SGML产品文档信息标准，研究了EXPRESS语言与XML语言模式匹配关系以实现两者的一致表达，研究了XML表达的STEP和SGML的网上动态关联，给出了统一表达的实例以证明可行性。