液压系统油液污染监测及分析技术

提出了几种现代液压油液污染度在线监测方法的技术原理,为液压系统油液污染度在线快速监测仪的研究开发提供指导.     

基于ARM的润滑油污染度在线监测系统设计

设计了一套基于ARM处理器的润滑油污染度在线监测系统。介绍了系统的各个组成部分及功能;重点介绍了以STM32F103VC 32位ARM为核心的硬件平台,包括ARM核心、通讯、电源、数据采集模块的设计。系统可以稳定、准确在线监测润滑油污染程度,为更换油液提供依据。     

一种基于滤膜堵塞的在线油液污染测试系统

开发一种在线油液污染检测系统,该系统以滤膜作为传感元件,通过专门设计的配重系统实现恒压测试,可实现在线自动清洗、自动取样、自动检测,避免了二次污染和人工干涉对检测结果的影响,为故障诊断提供了可靠的数据.     

液压油污染度在线监测系统研制及实验研究

油液污染是液压系统最主要的故障根源,而现有的油液污染检测设备价格昂贵、检测周期长、对操作环境要求严格.该文以特制滤膜为敏感元件,恒功率淤积法为技术原理,结合计算机技术在测量与监测方面的应用,研制出一套基于MCGS工控组态软件的液压油污染度在线监测系统,并完成了对在线监测系统的实验研究.实验研究结果表明,系统监测结果准确可靠,满足了鉴定油液污染等级的要求,可用于油液污染度的现场在线监测,具有一定的推广应用价值.     

SGA2723矿用汽车液压系统油液污染度的在线检测系统的研究

通过现场设备跟踪试验分析了液压系统污染源及种类,通过对有关油液污染控制理论和在线监测方法的深入研究和分析,采用光散型自动颗粒计数器结合虚拟仪器在测控系统中的应用,自行开发了一套基于虚拟仪器的油液污染在线监测系统。     

基于滤膜堵塞型的油液污染检测系统的设计

针对基于滤膜堵塞检测法的污染检测仪存在的测试范围不够宽、集成度不高、自动化程度低等问题,利用计算机及机电一体化技术,设计一种基于滤膜堵塞原理的在线油液污染度检测系统。该系统包含负压取样、恒压测试、滤膜反冲洗、PLC控制及ARM处理器等装置,能够实现在线自动取样和检测,且检测结果具有较好的可靠性。     

在线润滑油液光谱传感器技术研究

润滑油在车辆动力设备中具有润滑、冷却清洗、密封和防锈等功能,长期使用容易劣化变质.现行的定期换油方式存在过早换油造成浪费或者不及时换油导致设备磨损甚至无法工作的缺陷,而依据润滑油油液质量进行更换具有很高的经济和环境效益.为了检测润滑油的油液品质,基于光谱调制的原理,通过检测起光谱成分的变化来感知油液污染度的变化从而确定油液污染程度,开发了一种在线简易吸收光谱传感器,并对其传感特性进行了试验研究.试验结果表明,该在线光谱传感器的输出具有良好的稳定性,能够有效地检测润滑油液的品质.该传感器在润滑油退化分析中的应用前景广阔.     

便携式油液污染监测仪

便携式油液污染监测仪美国恩泰克科学公司最近推出一种便携式机器油液监测仪ＤＣＡ，该仪器的基本功能是数显污染报警（ｏｍｉｔａｌＣｏｎｔａｉｎ——Ａｌｅｒｔ——ＤＣＡ），除可以对机器润滑油监测外，还可分析测定工艺流体、冷凝液、液压油等其他电解质流体中的污染...     

工程机械油液污染度快速监测仪研究

介绍一种８０９８单片机控制的工程机械液压系统油液污染快速监测仪。     

基于MCU的电能质量在线监测仪

介绍一种基于MCU的电能质量在线监测仪的设计与开发,分别从硬件设计和测量方法2个方面阐述了其构成原理.硬件方面采用高速SOC单片机C8051F064为核心部件,系统由CPU主模块、模拟量采集模块、液晶显示与键盘模块、电源模块和通讯等模块组成;测量方法方面,通过对电能质量各项指标及其各种测量方法的分析比较,结合电能质量在线监测的要求,得到一套适合电能质量在线监测仪的测量方法,并将谐波源定位技术应用该监测仪中.该监测仪用于在线监测,具有很好的实时性和相当高的精度.     

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.