红外线温度传感器的设计与实现

本文介绍一种新型的红外线温度传感器。其基本工作机理是利用高精度红外位移传感器测量热膨胀系数较大的有机玻璃长度。用灵敏度为0.001℃的高精度石英温度计对其校准,证实这种仪器的温度测量精度可达10-5℃数量级,比较市场上现有的温度传感器,其灵敏度和线性度都有较大优势,具有广泛的应用前景。     

预紧封装光纤光栅温度传感器传感特性研究

为了获得稳定测量温度变化的光纤光栅温度传感器,笔者研究带预紧力的光纤光栅温度传感器的封装技术及其传感特性。通过温度传感理论分析,在避免光纤光栅对温度和应变的交叉敏感情况下,对光纤光栅温度传感器进行有限元Ansys应力分布进行模拟,可知本封装具有一定的减敏作用,温度测量量程增大,满足更多实际工程中的使用。环氧树脂DP420将带有预紧力光纤光栅封装在铍青铜材料的圆柱体内,在恒温鼓风干燥箱对光纤光栅温度传感器进行传感特性研究,40~120℃的范围内,每次升温5℃。所得结果,此光纤光栅温度传感器的温度灵敏度系数为23.81pm/℃,是裸光纤光栅传感器的2倍,且线性度达0.999以上。该文对光纤光栅工程化具有较大的应用价值。     

SAW谐振器型温度传感器

本文介绍一种用于通讯的ＳＡＷ谐振滤波器及相关电路所构成的ＳＡＷ谐振器型温度传感制的原理和特性，与ＳＡＷ延迟线振荡器型温度传感器相比，它具有频率高、插入损耗小、带宽窄、旁瓣抑制大等突出优点，实测结果表明：ＳＡＷ谐振器型温度传感器的短期频率稳定性大于１０＾－７，其灵敏度为－０．６ｋＨｚ／℃，具有良好的线性度和重复性，可用于高精度的温度测量。     

管式封装FBG大量程温度传感器及其特性研究

针对工程温度测量问题,提出了一种光纤光栅温度传感器的管式封装方法。利用耐高温AB胶将裸光栅粘贴于铜管内壁,实现增敏效果。首先简述了光纤光栅温度传感原理及其增敏模型,然后搭建了相应的温度实验平台,并且实验研究了铜管封装FBG温度传感器与裸光栅的温度感知特性。实验结果表明:在-40℃~120℃的区间范围内,铜管封装FBG温度传感器的灵敏度达到25 pm/℃左右,与理论值相符,且相较于裸光栅具有更高的灵敏度与线性度。该温度传感器具有良好的温度感知特性,可以应用于工程温度的检测。     

环氧树脂封装的EFPI-FBG复合压力温度传感器

为了实现对液压管路中液压油的压力和温度检测,研制了一种EFPI-FBG复合压力温度传感器。对该传感器的压力特性以及温度特性进行研究。首先,介绍了以光纤F-P腔和光纤光栅为敏感元件,利用环氧树脂将EFPI-FBG复合结构经过封装保护构成压力温度传感器结构以及制作方法。接着,建立了压力温度传感模型,对传感器受力进行了理论分析,并使用Matlab和有限元软件分析传感器的压力灵敏度和温度灵敏度。最后对传感器进行压力和温度实验验证。实验结果表明,该传感器的压力灵敏度为2.83μm/MPa,温度灵敏度为1.97μm/℃,温度监测范围为10～80℃,应用于压力测量时的有效工作温度为20～65℃。此EFPI-FBG复合压力温度传感器具有良好的线性度,较小的回程误差,灵敏度高,抗震性能好,可用于液压管路中液压油的压力和温度测量。     

高灵敏度长周期光纤光栅温度传感器的设计

为提高光纤光栅温度传感器的灵敏度,文中采取纤芯弹光系数大于包层弹光系数的长周期光纤光栅且在其包层外面涂覆一层随温度的升高折射率减小的薄膜材料,同时采用热膨胀系数大的金属封装光栅三种增敏措施。计算表明,增敏后的温度传感器其灵敏度系数为0.2375nm/℃,温度测量分辨力小于0.1℃。     

贴片封装的光纤Bragg光栅温度传感器

分析了光纤Bragg光栅的传感原理，提出了一种基于铍青铜片封装的光纤光栅温度传感模型。通过用一种耐高温胶将FBG粘贴在膜片材料上，使FBG在温度变化过程中一直保持张紧状态，保证FBG温度传感器有良好的重复性和线性。在20～200℃范围内进行温度实验，实验结果表明，FBG反射波长与温度有很好的线性关系，该温度传感器的温度响应灵敏度为0．0315nm／℃．实验拟舍值与理论值之差仅占理论值的2．9％。该传感器的温度测量范围大，可应用在油气井下较高温度环境的测量。     

高精度铂电阻测温转换电路的实践与分析

一、概述在各类测量温度的传感器中，铂电阻温度传感器与其它类型的测温传感器相比，它具有稳定性高，测量范围宽，线性度较好，易互换等优点。因此，它在各种温度测量中得到了广泛的应用。如何使钻电阻温度传感器在应用中得到较高的精度和稳定性，其关键问题在于如何使铂电阻温度传感器的良好特性获得扩展，同时又能不断克服和完善其自身存在的不足之处，这就为铂电阻测温转换电路提出了一个新课题。下面介绍的这种钥电阻测温转换电路就是为解决这一问题而精心设计的，该电路的转换范围可达上70℃，转换精度优于上0．03℃，年稳定度在100P…     

用于真空环境的光纤光栅温度传感器设计

光纤光栅传感器在航空航天领域有着广阔的应用前景,为了实现在航空航天真空环境下对卫星结构进行温度测量,对光纤光栅进行了特殊封装结构设计,在准确采集温度数据的同时,排除了结构应变对测量结果的影响,并对设计进行了有限元仿真分析。在-60-60℃的温度环境下,这种新型封装光纤光栅温度传感器的测试线性度为0.998,温度灵敏度为14.87pm/℃。为了验证其解耦特性,在MTS拉伸试验机上进行了测试,试验结果表明:结构形变带来的应变对该温度传感器没有影响,与理论分析相符。将其运用到实际真空环境进行对比验证,实验精度达0.15+0.002|t|℃。     

聚酰亚胺柔性温度传感器的制作与性能测试

基于微机电系统技术,在柔性聚酰亚胺(PI)基底上分别制作弓形与蛇形两种结构的铜薄膜与铂薄膜温度传感器。采用红外成像设备对传感器在通电状态下的热分布进行测试,结果表明PI基底具有良好的热绝缘性。对不同结构、不同金属薄膜的传感器性能进行对比分析,在25～90℃的温度测试范围内,4种温度传感器均具有较好的灵敏度和线性度,其中蛇形结构的铂薄膜温度传感器的线性度最好,线性相关系数达到了0.99933,其电阻温度系数为0.002 35/℃。     

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.