新型室温红外探测器的微电容快速测试系统

新型室温红外探测器对8～14舯红外辐射具有快速灵敏的响应，设计出用于该探测器的微电容测试系统，能够快速灵敏地将探测器输出的电容信号通过C—f、f—V变换电路转换为电压信号，然后由A／D转换电路变为数字信号后传到PC机进行信号处理。给出了硬件电路的实现方法，其采样频率为10kHz，电容信号的分辨率为10fF．这种测试方法也适用于其他微小电容式传感器的快速检测。     

多通道隔离电流输出型变送器信号调理系统

设计了一个应用于电流输出型变送器的多通道隔离信号调理系统,它集I/V转换电路、放大电路、滤波电路、隔离设计于一体,实现了将4～20 mA电流信号转换为可被A/D采样卡采集的电压模拟信号.经实验验证,该系统转换精度高、稳定性好、抗干扰能力强,已被应用在工程实践中.     

AD7862及其在智能电子水平仪中的应用

介绍了一种新型的应用于小角度测量的智能电子水平仪的设计。采用差动电容式倾角传感器与温度特性好的精密电阻构成阻容电桥；ICL8038作为交流电桥的激励源；超高速缓冲放大器LH0033和二次线性放大电路组成前置放大器；采用新型的12位A／D变换器AD7862，对电桥不平衡电压经前置放大器放大后的信号及激励源输出电压，作为两路信号同时进行采样和A／D转换，以消除激励源电压波动的影响。最后给出了具体的智能电子水平仪的硬件设计电路。     

惯性仪表数据采集的一种实现方法

惯性仪表(陀螺仪和加速度计)是惯性导航系统中的核心部件。为便于导航计算机的数字处理．惯性仪表输出的信号通常要经过A／D或V／F转换。本文介绍惯性仪表输出信号经V／F转换后的信号处理方法，即陀螺仪和加速度计的输出经过V／F转换变成频率信号以后利用82C54构成的电路将其转化成具有一定脉冲当量的脉冲信号供计算机处理，按这种方法处理，计算机对惯性仪表的数据采集就转化为对脉冲信号的计数。文中从硬、软件两个方面讨论了这一设计与实现的方法。     

核电站辐射监测系统BDCDE2DI型信号IO模块研发

秦山核电一厂的辐射监测系统中所使用的M-2024就地处理箱外接模拟量输入信号标准为0V～10V,经A/D转换后进行设备规定的某种控制。外部输入的各种电流信号需转换为电压信号,原有信号转换设备均已停产且无升级替代产品。为保证整个辐射监测系统的正常运行,确保整个核电站运行稳定安全,亟需一种能够保证原有I/O模块功能,且能运行稳定,安全可靠性高的新产品。本发明包括输入电流信号转换及隔离电路、直流电压起振电路、双电压稳压输出电路和运算放大偏置及输出电路。可以实现将输入的相互独立的两路电流信号转换成对应的两路电压信号进行输出,并将输入和输出信号进行隔离,避免相互干扰,且能够在工作环境温度发生变化时可以保证偏置电压精度。     

一种可驱动多路发光二级管的精密镜象恒流源

在对普通恒流源加以变形的基础上,设计了一种可以驱动多路发光二级管的镜象电流源。利用D／A转换器和精密运放实现V／I转换及恒流连续可调。采用晶体管扩流,ULN2003进行多路电流切换。测试表明,V／I转换电路的输入电压和镜象输出电流之间具有良好的线性关系,恒流精度达0．05％。     

音频信号分析仪

系统采用Atmega128单片机作为主控制器,并运用快速傅里叶变换(FFT)对音频信号进行频谱分析。输入音频信号经过双门限电路处理后,一路送入A/D采样,另一路经真有效值电路转换后送入A/D采样,结果经单片机处理,最后送液晶显示。该系统测量信号频率范围覆盖20 Hz～10 kHz,电压峰值范围10 mV～10 V,FFT得到的频谱分辨率为20 Hz,最终可得到音频信号的频谱与正弦信号失真度。     

高精度线性光耦HCNR200/201及其应用

本文介绍了高精度线性光耦器件HCNR200／201的主要特性及工作原理，并分析了一个使用该器件的模拟信号隔离转换的典型电路，它可将输入4～20mA电流信号隔离转换成电压信号。     

增益自动切换全量程I／V转换电路

本文介绍一种增益自动切换的I/V转换电路,它与相应的机器语言相配合,可实现较宽范围内的电流信号的快速全量程转入和转换,省去了A/D转换电路。     

汞膜电极快速差分常规脉冲伏安仪电路

本文介绍快速差分常规脉冲伏安仪的基本电路.极化电压电路部分的反相输入衰减电路、??持电路、恒电位电路.D/A转换电路.电流采样电路部分的i-E转换电路、多路摸拟开关电路、A/D转换电路.     

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.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.