线阵CCD驱动时序及信号采集系统的设计

文中设计介绍了一种基于FPGA和ARM的线阵CCD传感器驱动时序和信号采集的实现方法。该系统通过分析TCD1707D线阵CCD的驱动时序,采用Verilog HDL硬件描述语言设计出驱动脉冲电路。CCD正常工作后,产生的模拟信号经过预处理和高速A/D转换送入FPGA的基本宏功能模块FIFO(先进先出数据缓存器),通过异步缓存实现ARM处理器对采集信号的主控及后续应用。线阵CCD驱动时序及信号采集系统,是基于CCD传感器图像处理系统的重要组成部分,经过上位测试平台验证,能够提供准确的数字图像信号。     

TCD1252AP的驱动设计及数据采集

通过对线阵CCD的驱动时序研究,以TCD1252AP为例,利用一片现场可编程门阵列芯片FPGA设计出线阵CCD的驱动时序,并得到仿真波形。利用FPGA强大的处理能力对CCD的输出进行采集处理。使用该方法设计的电路简单实用,具有很好的应用价值。     

基于FPGA的模式可调线阵CCD驱动电路设计

光谱仪的微型化是光谱仪的发展趋势,其中具有高灵敏度、高信噪比、光谱响应宽、体积小特性的线阵CCD用作光电探测器成为研究热点。针对传统对CCD驱动电路遇到参数修改情况而需要改变硬件电路或重复烧写程序的缺点,以线阵CCD-ILX554B配合CCD专用信号处理芯片AD9826为例,结合FPGA控制芯片搭建了一个CCD驱动与信号采集系统。通过研究CCD与AD9826内部结构并分析控制驱动时序,结合Verilog HDL语言,设计了CCD工作模式、积分时间及工作频率软件可调整的CCD驱动系统,硬件电路设计考虑EMC并设计针对CCD输出信号的处理电路与数据传输模块。实验结果表明,该设计成功地驱动了线阵CCD并实现了模式可调,进行数据传输,且电路体积小、控制时序精确,可用作微型光谱仪的光电探测电路。     

基于FPGA的高速彩色线阵CCD实时图像采集系统

文中设计了一款彩色线阵CCD实时图像采集系统,选用FPGA作为主控芯片。该系统完成了线阵CCD传感器、模数转换芯片的驱动、数据采集与转换。转换后的数据通过FPGA预处理后,由USB2.0传输至上位机实现图像实时成像。结果表明:设计的彩色线阵CCD实时图像采集系统能够满足工业应用要求,每行像素点达2 098个,行频可达9 000 fps。     

基于线阵CCD的织物图像采集系统

介绍了线阵CCD传感特性和CCD驱动时序.设计了一个新颖的基于数字信号处理器DSP的线阵CCD驱动电路、CCD输出模拟信号采集和串行USB接口为一体的CCD织物图像传感及其数据采集系统.给出了该系统硬件原理图,分析了系统工作原理.该系统硬件线路简单可靠、性价比高,并配有与上位机通信的USB接口,能高速实时地将织物图像信息传送至上位PC计算机.     

角膜图像采集系统中的CCD驱动设计

针对角膜图像采集系统开发过程中的面阵CCD图像传感器驱动进行了设计。选用ICX424AL面阵CCD作为图像采集系统的图像传感器,分析了ICX424AL的驱动时序要求,介绍了高性能模拟前端处理芯片AD9949A内部主要电路模块的工作原理及相关电路的寄存器控制方法,实现了基于CPLD与AD9949A的ICX424AL驱动设计。最终测试结果显示,CCD可产生正确的模拟信号输出,将数字视频信号采集到计算机后,能够得到良好的图像采集效果。     

基于网络的线阵CCD信号采集系统的设计

针对现代数据采集领域的网络化趋势,设计出一种新型线阵CCD信号采集系统。采用FPGA为核心控制器,产生每个模块所需要的驱动时序。模拟前端处理器将采集到的CCD信号经过信号调理和A/D转换后,通过高速网络接口芯片W5300传送至PC机,PC机最终将采集到的CCD信号显示在接收软件上。不仅能够解决片上、专用的问题,而且使机器视觉技术结合网络技术,实现了高速、实时、网络化的信号采集系统。实践表明:该采集系统可以做到在任何有网络的地方都可以使用,有后期研究价值。     

基于单线阵CCD的物体宽度检测装置

设计了利用单片线阵CCD实现了物体宽度检测装置。该系统由主控芯片、线阵CCD、电压匹配电路、信号采集、数据处理和显像构成,用FPGA驱动CCD并将输出信号进行数据处理实现了物体宽度的检测。实验结果表明:该装置能够实现对单线阵CCD的驱动,能够实现物体宽度的基本检测。     

高帧率彩色线阵CCD实时成像系统的设计与分析

文中设计了一种满足工业需求的彩色线阵CCD实时成像系统。该系统实现对线阵CCD的驱动,控制专用的ADC采集芯片对CCD模拟信号进行采集。将采集到的数字信号由FPGA内部预处理后,通过USB2.0传输至上位机实现图像的拼接、显示与保存。最后,对线阵CCD静态图像噪声和动态成像特点进行了分析。研究结果表明:设计的线阵CCD图像采集系统,像素分辨率最大5 340,帧率可达6 250 fps,满足工业应用要求。CCD所选用的TDI模式,对于高速目标有更好的成像质量。     

高速线阵CCD驱动与数据采集系统设计北大核心CSCD

以TCD1708D为感光元件设计了高速线阵CCD驱动与数据采集系统。分析了CCD同步时序的要求,选用EP4CE10F17C8作为主控芯片,利用Verilog HDL语言设计CCD驱动信号,设计了驱动硬件电路驱动CCD得到准确的输出。分析了CCD输出信号特征,使用虚拟仪器技术完成了对CCD奇偶双路模拟输出信号的采集,以LabVIEW为平台开发了上位机软件,采用NI-DAQmx驱动程序控制PCI-6115,实现了高速线阵CCD数据采集,并且能够实时显示CCD波形、图像数据。实验结果表明采集的数据边缘特征清楚,该系统结合了FPGA和虚拟仪器技术的优势,驱动运行稳定,数据采集准确,程序可移植性强。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.     

Fractional order nonsingular terminal sliding mode control for flexible spacecraft attitude tracking

This paper investigates a fractional terminal sliding mode control for flexible spacecraft attitude tracking in the presence of inertia uncertainties and extern...     

奥氏体不锈钢表面双辉等离子渗锆的动力学

利用双辉等离子渗金属技术在0Cr18Ni9Ti奥氏体不锈钢表面制备了一层均匀、致密、呈良好冶金结合的渗锆合金层,并对1 060℃下的渗锆动力学进行了研究。结果表明:随着距锆合金层表面距离的增加,锆元素的含量呈梯度递减,扩散系数逐渐减小,而扩散激活能逐步增大;在1 060℃采用双辉等离子技术渗锆时,渗锆合金层表层的空位密度为2.945×(1012~1013)cm-2,与相同温度下采用常规渗金属工艺相比,提高了1~2个数量级。     

气化炉三维扫描测量与数据处理

以德士古气化炉耐火砖的内壁蚀损检测设备为基础,对采集到的点云数据做了进一步处理.通过对数据的筛选和剔除,实现了数据点的平滑降噪细化和精简.然后利用点云对整、网格划分和分色显示等方法,最终完成了内壁腐蚀情况的三维建模.重点讨论了点云数据的预处理及后处理的方法,并根据内壁耐火砖的腐蚀阈值,提出了一种气化炉内壁腐蚀区域的识别与分割方法.对耐火砖的腐蚀分析、气化炉的生产与维修提供了可靠依据,并在工程应用中获得了一致认可.