工业光学检测中定位点的识别

提出了一种新的定位点识别方法,在无需事先学习定位点图形的条件下,对有较强噪声的圆形或环形定位点实现准确快速的识别和定位。利用图形质心性质和圆形定位点图像几何形状特征搜索其质心位置,根据图形的填充率判断其形状,从而完成对定位点的自动识别。经实际测试,证明这种方法在多种复杂的图像环境中可以对定位点进行定位和识别,并得到较高的定位精度。实验结果也表明该方法还可以应用到其他一些图形物体的图像识别中

Design of Digital Image acquisition System Based on FPGA and USB 2.0

随着技术的发展,工业检测技术受到人们的重视,其中图像检测由于其具有直观,方便,信息量较全面而使得它在工业检测方面具有重要的应用。以fPgA作为控制核心,设计了一个小型图像采集系统。通过fPgA实现CMOS图像传感器的初始化、图像数据采集、存储、uSb接口芯片的控制;使用uSb 2.0接口实现图像数据传输;使用VC++编写上位机程序对图像进行实时显示。经过测试,整个系统能够稳定工作,满足设计目标。With the development of technologies,the industrial detection technology has been paid more attention,in which the video detection plays an important roles in the field of industrial detection because of intuitive,convenient and more comprehensive information from it.A small image acquisition system is design by using FPGA as the cotroller.The initialization of CMOS inage sensor,image data acquisition,storage and control of USB interface chip are implemented by using FPGA.The image data is transmitted from FPGA to host via USB 2.0 interface chip,and displayed on the host program.Testing results show that the stability of the whole system meets the design goals

New Method for Analyzing Raman Spectra of Hydrogen-free Diamond-like Carbon Films

dlC薄膜的拉曼光谱表征主要依靠d峰和g峰的强度比值(Id/Ig)来定性判断SP3含量,但当SP3所占百分比高于20%时,Id/Ig值对SP3含量的变化不敏感,判断的误差很大。采用直流磁控溅射和多弧离子镀制备了一系列无氢dlC薄膜样品,并测量了样品的拉曼光谱和维氏硬度。通过数据分析,发现薄膜硬度和拉曼光谱中的g峰半峰宽具有很好的相关性,因而提出通过g峰半峰宽来定量判断dlC薄膜中SP3含量的拉曼光谱表征新方法。The ratio between intensities of the D peak and the G peak(ID/IG) is used to estimate sp3 content of the DLC films.However,this method has limitations.When sp3 content exceeds 20%,ID/IG has very low correlations with the content of sp3,therefore,estimation of sp3 content using this method could lead to significant error.DC-magnetron sputtering and multiple-arc ion plating are used to deposit a series of hydrogen-free diamond-like carbon samples.Raman spectra and Vickers hardness of samples were measured and analyzed.A strong correlation between the hardness and G-peak's full width at half maximum(FWHM) was discovered.The results show that it's feasible to measure the content of sp3 by using the G-peak's FWHM in Raman spectra.福建省半导体照明工程技术研究中心资助项目(2006H0092

An improved normalized cross-correlation algorithm for inspection of printed circuit boards - art no 635719

Conference Name:6th International Symposium on Instrumentation and Control Technology. Conference Address: Beijing, PEOPLES R CHINA. Time:OCT 13-15, 2006.Template matching is one of the best and the most widely used pattern recognition method. Normalized cross-correlation (NCC) is the main matching algorithm for template matching method. For templates with significant gray-level variations, also called features, normalized cross-correlation can be a very simple and effective template matching algorithm, even in cases of noisy data and changing lighting level. In the application of automatic optical inspection of printed circuit board, many electronic components have labels on them and can be used as features for cross-correlation template matching. However, there are quite a few components that have no labels, like some type of capacitors and transistors. They are identified by the color or the shade of gray-level instead. These components pose great difficulties for traditional normalized cross-correlation, which will pick up some random variations as features instead and cause false alarms. People-used to deal with this problem by including part of the background into the template to create some artificial features, or by selecting some alternative special algorithms. Both of these methods are not ideal. Because the first method will make the template less universal and subjects to background variations; while the second method will loose many of the nice properties of cross-correlation algorithm. We propose an improved image cross-correlation algorithm, which can recognize both feature based templates and uniform color or gray-level based templates. Compare with the traditional cross-correlation algorithm, this new algorithm can be more accurate and more universal. Experiments have shown that this new algorithm can detect feature-rich, uniformly colored, and uniformly gray templates effectively

Molecular Dynamics Simulation of High-pressure Phase Transition in Iron

采用分子动力学(MD)方法,结合原子间多体势函数,模拟了bcc铁(αFe)在高压下向hcp铁(εFe)转变的过程,并与实验数据进行了比较.系统的压强通过计算维里压强获得,并通过Berendsen方法进行调整和改变.还采用相同的原子间势模拟bcc和hcp两种不同结构的铁,对高压下铁相变的机制和相变压强进行直接的计算和模拟,以对采用的原子间势进行更严格的检验和修正.模拟计算得到超高压下(>15GPa)两种结构的PV曲线图以及hcp铁的c/a值等相关结果,都与实验结果有较好的符合.而在较低压下(0～15GPa)PV关系中常用的铁的原子间势对bcc铁仍有很好的模拟效果,而对hcp铁则效果不是很理想.因此,铁的原子间势还有待进一步改进.Molecular dynamics method (MD) is used to investigate the iron bcc to hcp phase transition under high pressure,and the simulative results are compared with experimental results.Many-body inter-atomic potential is chosen to calculate inter-atomic force.The pressure of the system is obtained by calculating virial pressure of the system,and is adjusted via the Berendsen method.The relation of P-V and the ratio c/a of iron has been obtained and compared favorably with experimental results.Simulating two crystal structures simultaneously posts higher requirements to the chosen inter-atomic potential and can help the development of more accurate potentials.The simulation of bcc structure agreed to the experimental results perfectly.But the result of hcp structure is not satisfying.So,the atomic potential of Fe needs more improvements

Study of colors of diamond-like carbon films

National Basic Research Program of China [2012CB933502]Reflective and transmissive film interference colors were calculated for DLC films on the Si and SiO2 substrates. The calculated interference colors were compared with photographed colors of the prepared DLC samples. The observed film colors were found to match reasonably well with the corresponding calculated colors, indicating that DLC film colors come from interference instead of color center effects. Color charts for DLC films on the Si and SiO2 substrates with various optical gaps were constructed, and the relationship between interference color and film properties such as optical gap, thickness and substrate were investigated. Usefulness of the calculated color charts in estimating optical gap or thickness of DLC films were demonstrated

Metallic contacts to nitrogen and boron doped diamond-like carbon films

National Natural Science Foundation [50672079]; National Natural Science Foundation of China [60837001]Hydrogenated diamond-like carbon (DLC) was deposited using a radio-frequency plasma-enhanced chemical vapor deposition method. Electrical properties of Al, Au, Ti, and Zr contacts to nitrogen and boron doped DLC films have been studied, and mechanisms of the observed current-voltage (I-V) characteristics are investigated. Linear I-V characteristics were observed for Au, Ti, and Zr contacts to both nitrogen and boron doped DLC films. A band structure model for metal-DLC contact is proposed to explain the observed ohmic contacts. Fermi level shifting at the surface of DLC films produces an ohmic resistive layer instead of a Schottky barrier for metal-DLC contacts. Al contacts to both nitrogen and boron doped DLC films show nonlinear I-V characteristics, which are attributed to a dielectric layer of carbide (Al(4)C(3)) instead of a Schottky barrier suggested by other groups. Inert elements such as Au and Pt, and transition metals such as Ti, Zr and W. which form conductive carbides, are considered good contacting metals for electrical studies of DLC films. (C) 2009 Elsevier B.V. All rights reserved

The Implementation of Visual Navigation Car Based on FPGA

视觉导航作为新兴起的技术,受众多研究者的青睐.设计了以现场可编程门列阵(fPgA)为控制核心的自主导航小车,采用一种新颖的自适应路径识别算法实现路径的识别与提取,并结合圆弧路线规划和控制策略完成小车的自主导航控制.自适应路径识别算法使导航小车可以适应多种光照和路面条件.测试结果表明,小车能够在不同光照条件下的实验室和露天田径跑道环境中实现较好的导航效果,在田径跑道上的导航测试中,小车的最高运行速度达到3.5M/S.As a new technology,visual navigation has gained a lot of interests.We designed a visual navigation model car with field programmable gate array as central control unit.A novel adaptive track recognition algorithm and a circular arc navigation planning strategy were used in this navigation car.The adaptive track recognition algorithm enabled the model car to navigate visually in multiple lighting and tracking conditions.The ability of our model car to navigate correctly in different indoor and outdoor conditions was demonstrated.During tests on an open track field,the car was to run with a maximum speed of 3.5 m/s while navigating accurately

A track following visual navigation model car based on FPGA

Conference Name:2013 2nd International Conference on Measurement, Instrumentation and Automation, ICMIA 2013. Conference Address: Guilin, China. Time:April 23, 2013 - April 24, 2013.Korea Maritime University; Hong Kong Industrial Technology Research Centre; Inha UniversityA novel adaptive track finding algorithm is designed, which combines the function of track finding and image binarization. The combination of these two functions allows the system to determine the binarization threshold adaptively, and perform accurate visual navigation in diverse lighting and track conditions. A circular arc path planning strategy with a single measurable control parameter is used to guide the model car to the track. The circular arc path planning strategy is easy to implement and delivers fast and accurate responses to the track. ? (2013) Trans Tech Publications, Switzerland