基于高速数据采集的发动机参数远程测试系统

将虚拟仪器技术与USB接口技术相结合,实现高速采集的网络化测试系统.USB总线可以实现对数据实时高速的采集,把采集数据传送到主机后再通过LabVIEW的网络通信功能进行数据的远程传输.介绍了USB接口模块硬件和软件的设计方法,阐述了LabVIEW开发平台上网络化传输的实现方法,结合发动机测试,实现发动机参数远程虚拟测试系统.     

基于MODBUS无线总线测控系统

本文提出了将工业现场总线ModBus通讯标准引入到nRF无线通讯技术中,组成ModBus无线总线测控系统.采用nRF905芯片作为无线收发模块的核心,主机和分机的信息交换以射频无线总线的方式实现,数据的无线传输遵循ModSus(RTU)通讯协议,采用半双工的工作方式,频率工作在ISM频段.按照ModBus协议的RTU模式,设计RTU消息帧的结构和格式,通过无线总线实现了主机与分机之间的信息传输和控制各个分机的工作.     

基于CH372-USB总线芯片的FPGA控制器

USB逐渐成为现场调试和实时监测设备的标准接口,在比较了几种实现USB接口的方式后,采用FPGA与带USB底层协议的总线芯片来实现USB接口通信。采用FPGA作为主控芯片,设计了基于CH372-USB总线芯片的控制器,论述了控制器工作的原理和核心状态机的设计过程,解决了FPGA控制CH372时,CH372对时序和命令输入的要求。最后,搭建实验硬件平台,验证了该方案的可行性和有效性。     

基于USB接口的高精度电荷校准仪

采用虚拟仪器技术、直接数字合成技术和计算机技术设计了电荷校准仪,其工作状态由计算机USB接口控制,能输出多种波形的电压和电荷信号,电路中采用双DAC结构实现了幅值的精确控制.计量检验结果表明设计的电荷校准仪精度高、性能稳定,能够满足高精度的压电测试系统和电荷放大器的校准需要.     

典型工业网络系统实验平台的设计

基于工业以太网技术及现场总线技术,设计并建立了一个典型的工业网络系统实验平台,阐述了系统总体设计思想、工程架构,以及具体的软硬件实现方案.详细描述了基于OPC技术的工业以太网与现场总线PROFIBUS通信连接设计、现场总线PROFIBUS与AS-i网络互联设计,阐述了该系统平台的科研及实验功能,其具体工程实现技术也可以很容易地应用于实际的现场总线控制系统设计实践中.     

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.     

线阵CCD的高速信号采集与USB数据传输系统设计

介绍了一种用于线阵CCD高速位移传感器的信号采集与USB传输系统.系统以DSP为控制核心,采用高速AD转换器件AD9238和USB2.0接口控制芯片CY7C68013实现信号采集与高速数据传输的功能,给出了硬件电路和相关程序的设计方法.实验表明:在DSP的控制下,系统实现了CCD传感器信号的高速采集和实时传输.     

基于USB总线的LCOS数码彩扩仪驱动设计

介绍了一种利用USB传输视频数据的LCOS数码彩扩仪驱动设计方案。采用专用USB芯片实现图像数据传输,CPLD及SRAM实现视频数据的缓存,并由CPLD设计产生XGA信号驱动后端的LCOS控制芯片,最终实现了数码彩扩驱动系统的稳定输出,为实现LCOS数码彩扩系统提出了一种新思路,具有相当的实用价值。     

基于USB接口的音频信号采集系统设计

对USB总线技术进行了介绍。设计基于USB2．0接口技术的数据采集卡。介绍了USB的硬件设计、固件设计和驱动程序设计。给出具体的硬件设计方案;进行固件设计与驱动程序设计,介绍CY7C68013的GPIF接口的设计。利用USB与DSP技术实现音频信号的数据采集、处理与传输。     

基于CPLD的膜片钳数据采集系统--UDA-Ⅰ数据采集器

针对膜片钳实验系统自动化发展的需要,采用基于CPLD芯片的数字逻辑控制单元和USB1.1数据传输总线,研究并实现了一种新的数据采集系统--UDA-Ⅰ(USB Data Acquisition,Ⅰ型)数据采集器.实验证明,本数据采集器的数据传输速率达到100K Bytes/s,信号噪声在土10 mV范围内,能灵敏、准确地实现数据传输,符合膜片钳实验高速数据传输的要求.     

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...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

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。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

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.