基于DSP核心的指针式仪表自动检定装置

绝大多数指针式仪表的检定系统是由计算机来完成图像的采集、计算、控制、装置自动调节等功能,由于基于计算机的视觉系统使用PC作为其核心处理器,系统都比较庞大,因此应用范围受到了限制.为了更好的解决指针式仪表的检定工作和使仪表检定工作更加简便化,论文针对小型指针式仪表设计了以DSP为核心的自动检定系统,保证检测速度和精度并且检测方便,经实验数据证明,该装置能够快速,方便地达到检定效果.     

简易仪表测力器的研制

为保证仪表使用功能的稳定,制做了简易仪表测力器,快捷准确,满足了检定仪表测力以及测力变化的需要。     

特种设备定期检验中哪些设备的压力表必须检定

特种设备上定期检验所关心的主要是有安全防护作用的仪表,对这些仪表应实行强制检定。规定以外的其他计量标准器具和工作计量器具,使用单位可以自行决定定期校准或者送其他计量检定机构检定或校准。     

热工仪表维护管理系统的设计

本文主要介绍了热工仪表维护管理系统软件的设计原理和方法，采用Power Builder作为数据库前台开发工具，实现对现场仪表，过程测点等的维护,校验和历史记录查询等功能。文中给出了主要数据库的结构和系统功能模块的设计。     

加热炉安全仪表系统安全完整性等级评估

基于国际标准IEC61508/61511(GB/T20438/21109),研究安全仪表系统功能安全技术,形成了一套过程危险与风险分析、保护层分析和故障树分析相结合的安全仪表系统安全完整性等级评估技术方法。将该方法应用于加热炉装置,针对不满足安全完整性等级要求的安全仪表功能回路,提出了相关建议措施。应用结果表明:加热炉安全仪表系统安全完整性等级评估为安全仪表系统合理、有效地设置和科学维护管理提供理论依据和技术方法,对于提高加热炉安全可靠性,减少由于安全仪表系统误动引起的非计划停车具有重要作用。     

仪表指示器不回零位值的确定

为了保证测量仪表能够准确可靠地工作,通常我们都要将制造厂提供的仪表在装机应用前,按技术条件的规定进行检定;另外,对使用中的仪表也要进行定期的检定与维修。因而一些具有机械反作用力矩仪表的指示器(或指针)不回零位值的测量,则是必须检定的项目之一,因为在国家标准GB776—76《电测量指示仪表通用技术条件》的规定中,仪表指示器不回零位值的确定是衡量仪表技术性能优劣的主要指标之一。     

火电厂压力检测仪表精确度快速检定系统

研制了一套火电厂压力检测仪表精度快速检定装置,并分别对检定设备的选择、试验仪表、检定项目及检定方法进行深入分析。分析认为:该装置可对送检压力表的零位误差、示值误差、回程误差等常规误差快速检定,同时具备不确定度评定与检测结果检验的功能,操作方便,检定结果准确。     

高压直流输电阀冷系统流量类仪表检定装置的设计

介绍了一种以超声波流量计为标准流量计的阀冷系统流量类仪表检定装置。对该检定装置的硬件设计、控制系统以及检定方式进行了详细阐述。该装置尤其适用于大口径流量计的检定,实现了人机交互、数据采集、打印报表、数据归档等功能,提高了流量仪表检定装置的自动化水平。     

风速检定自动控制系统的研制

随着国民经济的快速发展和人们对生态环境的重视，各种测风仪表广泛地使用在各行各业中。对风速仪表开展计量检定工作是各级检测结构从事的基本业务工作之一。风速检定自动化控制系统是为检定风速传感器和风速仪表而设计的一套集现场数据采集、数据处理和风机控制的计算机自动控制系统，本文就如何在风速仪表检定中实现自动控制技术进行了详细论述。     

多通道多参数电测量仪表的自动检定系统

针对现有电测量仪表检定系统自动化程度不高、检定效率低的缺陷,提出一种基于多功能过程校验的仪表自动检定系统。该系统由配置多串口卡的PC、过程校验仪、PLC和条码扫描枪组成,能自动产生高精度标准信号,自动获取待检定仪表测量值和标准信号值,自动记录、处理检定结果,从而实现电测量仪表的全自动检定。     

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.