HY3000采集器雷击故障诊断

文章介绍了DZZ5型自动气象站的结构及HY3000主采集器。通过近几年在南平市各县区的维修实践,文章总结了DZZ5型自动气象站雷击故障诊断方法,同时介绍了4次不同的HY3000采集器发生雷击故障排查实例、更换主采集器注意事项及防雷击建议,供台站保障人员参考。     

气象自动站采集器结构及维护

随着气象事业发展,气象自动站不断更新换代,气象自动站采集器型号、功能、配置也不断更改。为更好保障气象装备正常运行,文章对常用气象自动站采集器的结构原理及维修维护方法进行了调查研究。     

ZQZ型自动气象站常见故障的维修

本文结合自动站现场维修工作中出现的相关问题,从通信、电源、采集器主板、传感器等多方面进行处理分析,介绍了自动站各种故障相应的解决方法,提高了探测设备的稳定性和探测数据的准确性.     

常德市区域自动气象站维护维修方法研究

文章简要介绍了常德市区域自动气象站的基本情况、维护维修中存在的问题,并针对采集器、电源、传感器等方面出现的故障提出了相应的解决方法;通过在实际维护过程中总结的经验,为做好市县两级区域自动气象站的运行维护提供可行的技术方法,进而有效提高区域自动气象站的数据传输及时率和数据可用性。     

滚动轴承故障诊断与检测研究

提供了一种用于故障诊断检测研究的通过分析振动信号波形和频谱进行故障诊断检测技术,借助机械振动分析及轴承故障诊断试验台进行测试,将传感器安装在试验台的轴承座上,输出直接接到采集器端口,采集器将振动信号采集输入到计算机中,观察并记录得到的振动信号波形和频谱,通过频谱的变化规律,找出有缺陷的轴承,并与实验结果进行对比,验证该方法的可行性,有助于对滚动轴承缺陷精确的定性、定量表征作更进一步的理论研究,为后续状态监测提供参考,为实现机电设备的预测性维修提供可靠方法。     

区域自动气象站日常故障检修

区域自动气象站常年布设在野外,不便维护,设备损毁多、故障率较高,造成设备不能正常运行或数据无法上传到中心站,给台站保障人员带来了很多工作困难。文章结合区域自动气象站维修中常见的故障及解决方法,以DZZ6型采集器为例,介绍了本地区关于自动气象站故障判定的经验,仅供台站保障人员参考。     

基于微机电系统的振动能量采集器件设计分析

微能量采集器中电容式采集器易与IC工艺集成,目前已知的传统电容式微能量采集器都需要外加电压,这在很大程度上限制电容式微能量采集器的实际使用。针对该问题,基于微机电系统工艺,提出功函数原理电容式微能量采集器,给出采用两种不同金属作为电容极板电极的采集器原理模型设计,并建立相应系统数学模型,计算大致悬臂梁长度的设置与范围,使用有限元模拟软件ANSYS进行进一步分析与优化设计。在此理论基础上设计出的新型振动能量采集器,可克服传统电容式微能量采集器需要外界提供电源这一缺点。     

降雨径流采集器的无功损耗分析及节能电路设计

为了延长降雨径流采集器的待机时间研制一种节能电路。首先通过对采集器功耗的分析建立采集器的待机时间模型;再利用采集器待机时间模型确定影响采集器待机时间的关键因素是无功损耗;最后通过研制一种节能电路降低采集器的无功损耗,进而延长采集器的待机时间。实验结果分析表明:当采用1500m A的锂电池时,采集器的待机时间提高了837.15倍,达到1.65×10~4h。该节能电路可有效地提高采集器的待机时间。     

基于USB及CPLD的超声信号采集器设计及应用北大核心CSCD

为满足便携式设备在工程应用中对多路高频信号采集功能的需求,研制了一套以CPLD为时序控制器,以高速模/数转换器(ADC)为信号采样器,以USB接口为数据传输通道的多路信号采集器,最多可进行16路差分信号的高速采集。采集器使用数据缓冲器协调各路数据的采样与传输。通过对USB固件程序、CPLD时序控制程序及上位机接口程序的开发,采集器可实现单路信号采样频率10MHz以上,采样数据直接传输至上位机软件MATLAB中处理。以采集器在气液两相流体积流量测量的应用为例,体现了所设计的信号采集器具有实用、便携的特点。     

驰振式风能采集器的研究进展及应用

驰振式风能采集器作为风致振动式采集器的典型结构,具有良好的采集性能,在低功率设备,如微机电系统(MEMS)和无线传感设备等方面有着极大的应用前景.文中介绍了基于不同原理的驰振式风能采集器的最新进展,主要分为基于横流驰振和基于尾流驰振的风能采集器,分析总结了各种采集器的特点及性能,包括结构设计、切入风速、输出功率及有效风...     

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.