气象雷达全固态调制器的几种故障排除方法

文章阐述了气象雷达全固态调制器的工作原理及其主要故障的分类,并针对气象雷达在业务运行过程中出现的调制器组件典型故障进行了分析,介绍了如何根据报警信息、故障现象进行定位和排除的方法。文章所述3例雷达故障现象不尽相同,但都与调制器组件相关,针对高压打火可能对发射机造成的严重危害,需要熟练掌握高压线路和模块组件线路结构及信号流程,才能更快更好的排除雷达故障。     

新一代天气雷达回波数据质量异常的故障分析和排除

以成都新一代天气雷达（CINRAD/SC）的1次回波减弱故障为例,详细介绍了分析和排除此次典型故障的过程：从回波减弱这一故障现象,逐步检查终端处理软件中信号处理器RVP7的参数设置、接收通道、发射系统,最终确定因发射系统中高功率电源分机故障导致雷达发射功率降低,回波减弱。通过对本次故障的分析和排除,从中总结获得了几点关于雷达维护维修的有益启示。     

CINRAD/SA雷达天线空间定位故障分析及处理方法

文章描述了滨州CINRAD/SA雷达自2015年02月运行以来发生的两次天线空间定位故障,通过雷达产品的日常观测、与邻近雷达站对同一降水回波的位置比较以及对地物杂波位置的观察,台站及时发现故障并进行了处理。同时介绍了发现故障的过程,分析了有可能引起天线空间定位故障的原因,为台站快速发现并排除雷达天线空间定位故障提供思路。     

CINRAD/SA天气雷达接收机测试通道故障排查方法

文章介绍了CINRAD/SA雷达接收机测试通道的组成,并分别对测试通道各主要部件故障判断方法进行了介绍,同时提出了当出现标定数据异常和系统软件报警且无法对故障进行精确定位的情况下,优先检查测试通道,利用雷达系统软件配合机外仪表,通过测量微波器件各通道的增益或衰减量进行故障定位的方法,为雷达业务保障人员快速排除雷达故障提供了参考。     

CINRAD／SA雷达接收机故障个例分析与处理

由于A／D高速采集模块长时间运行会导致该模块不能正常工作,2011-11-22,营口CINRAD／sA雷达接收机就因此而无法正常采集和传输数据。文章对本次CINRAD／SA天气雷达接收机的故障个例进行了分析,提出了相应的应对措施和排除方法,同时总结了雷达运行中出现的其他接收机故障,为快速检修雷达、排除故障积累了经验。     

浅析雷达发射机调制器故障诊断与排除

雷达发射机调制器的性能直接影响雷达整机技术指标,为了实现调制器工作的可靠性,研究雷达发射机调制器故障诊断与排除方法就显得格外重要。本文首先分析脉冲调制器工作原理,在此基础上提出雷达发射机调制器故障诊断方法,最后给出了脉冲调制器工作故障的具体表现以及故障排除实例。     

多普勒雷达发射机过流故障分析与处理

通过一起典型的多普勒天气雷达IGBT过流故障,对多普勒天气雷达发射机高压部分的回扫充电调制器组成、工作过程、故障形成的可能原因进行了阐述,并揭示出对多普勒天气雷达发射机高压部分的检修要点,可对排除这类高压故障时提供帮助。     

CINRAD／SA型多普勒天气雷达故障维修技巧

通过近几年多普勒天气雷达的使用情况,结合已出现的故障等问题,从故障现象、故障检测以及故障排除三个方面,阐述了多普勒天气雷达使用过程中出现的发射系统、接收系统、伺服系统故障,总结多普勒天气雷达的检修思路和方法。     

浅谈由散热风扇引起多普勒雷达失锁的分析与总结

直升机在地面及近地面时,多普勒雷达(以下简称雷达)失锁,在飞行时,雷达锁定,工作正常。该问题是由载机散热风扇工作引起的雷达失锁。通过对该起故障的排查、分析以及解决,为以后迅速排除同类故障积累了经验,提供了帮助。     

移动724XD型X波段脉冲多普勒天气雷达维护与故障分析

724XD型X波段脉冲多普勒天气雷达是一种先进的中频相参体制的X波段雷达设备,现介绍了该设备及其工作原理,并针对近年来该雷达的使用情况提出了一些具体的系统维护及故障判断和排除方法,为日后该雷达在突发气象灾害时能发挥积极作用提供了技术保障。     

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.     

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....     

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.     

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.