基于PCIe接口的高速数据采集系统

为了提高数据采集系统采样率和数据传输速率以及通用性,设计了一种基于PCIe接口的光传输高速数据采集系统。FPGA控制不同AD子板进行高速数据采集后,数据通过光传输Aurora协议实现光口和SSD进行大量数据传输和缓存。最后通过PCIe接口将数据上传至上位机。该系统能够稳定、长时间采集数据,能够实现最大传输速率为2 GB/s、最大数据存储量为60 GB的数据传输与存储功能。     

基于FPGA的高速数据采集系统设计

介绍一种基于FPGA的高速数据采集系统的设计方法,按照该方法设计出的数据采集系统能够实现高速实时数据采集和大容量深存储。该设计经过实际验证,工作稳定,能很好地达到预期要求。     

便携式高速数据采集处理系统

为实现对数据快速准确的采集,同时满足系统小型化、低功耗、低成本的要求,介绍了一种以数字信号处理器(DSP)和现场可编程门阵列(FPGA)为核心的便携式高速数据采集处理系统.在介绍了系统组成及基本原理的基础上,详细讨论了便捷式高速数据采集处理系统的电路原理设计和USB接口软件设计.这种设计可以提高采集系统的精度和稳定性.更好地满足了系统实时性要求.     

基于USB2.0的生物信号采集系统设计

介绍了基于USB2.0的生物信号采集系统设计原理与实现,提出了使用FPGA控制A/D转换器完成高速、高精度数据的采集和存储,同时给出了基于FX2实现高速数据传输的USB总线接口方案.按照该方案设计的生物信号采集系统可以实现不间断、大容量数据采集和传输.     

遥测信号及实时信噪比高速同步数据采集系统设计

提出了一种具有多路、多类型的遥测信号及实时信噪比信号采集、存储及显示系统的设计及实现.该系统选用FPGA作为整个系统的主控制器,利用多块大容量FLASH存储芯片实现了信号的高速同步采集.详细介绍了信噪比数据、模拟量数据与数字量数据的编帧结构和数据采集存储过程,解决了数据的远距离传输问题.系统采用CY7C68013来实现USB接口的高速数据传输,支持热插拔,使用方便灵活.     

基于FPGA的高速数据采集存储系统的设计与实现

为提高存储测试过程中的数据采集速率,增大存储容量,设计了一种基于FPGA的高速数据采集存储系统。该系统选用高性能FPGA作为控制核心,结合高速AD转换芯片和大容量FLASH存储器完成数据的采集与存储;时AD逻辑控制、缓存模块等关键技术进行了详细介绍。试验结果表明,该系统最高采样率可达1．7MS／s,能够很好地实现数据采集与数据存储功能,运行效果良好。     

多频连续波雷达自适应数据采集系统设计

目前应用于雷达的数据采集系统应用环境单一,不能满足宽领域的应用需求.一种基于FPGA和I2C总线的多路自适应采样系统既可以用于多频连续波雷达数据采集系统中,又适用于常规工业领域中的数据采集.将采样帧数据存入E2PROM并通过FPGA与E2PROM接口设计实现了多路数据采样率可编程方法,并提出了一种基于FPGA片上集成的高速FIFO实现采集数据的高速缓存.由于采样率由程序控制,因此该方案具有较强的灵活性,已成功应用于实际系统.     

基于FPGA控制单片机接口的远程监测系统

介绍了基于FPGA控制单片机接口实现远程监测系统的设计.该系统采用双CPU结构,下位机负责采集现场数据,上位机控制和监测下位机,FPGA作为下位机接口的控制芯片实现现场数据采集、数据液晶显示等工作.通过RS485总线实现上下位机的远程数据通信.     

基于PXI的LVDS高速通信板卡设计

针对采集系统与计算机的高速数据传输问题,设计了基于PXI接口的通信板卡。板卡以FPGA为控制核心,控制LVDS进行数据采集,将数据通过PXI接口发送给计算机,通过WDM驱动结构完成PXI总线连接到计算机的软件接口,并编写上位机程序对板卡进行测速。不同于传统数据采集卡,没有采用专用的PCI芯片,单独以FPGA来实现PXI接口。测试证明,设计的通信板卡可以实现高速数据采集功能,速度可达107 MB/s,在节约成本的同时加快了PXI板卡的开发周期。     

基于FPGA的机载数据采集系统设计

针对机载数据系统采集的数据种类多、时间长、数量大等问题,本文设计了一种基于FPGA的机载数据采集系统.系统采用FPGA与单片机相结合的硬件架构,利用FPGA集成度高、在线可编程等特点,灵活、高效、准确地实现了高精度数据采集;另一方面,系统通过USB接口完成了与地面计算机之间的数据传送和任务接收.本文介绍了该系统的体系结构,重点讨论了系统实现中关于模块化设计和抗干扰设计的关键技术,最后给出了系统标定和测试的方法.实验证明,该系统工作稳定,采集精度高,可靠性好,具有很强的通用性和扩展性.     

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.