ZigBee无线传感器网络在矿井巷道监测系统中的应用

为了满足矿井巷道环境多参数监测的需求,根据矿井巷道地形的特点,介绍了一种可靠的基于ZigBee无线传感器网络的矿井巷道监测系统。详细阐述了以CC2430为核心的传感器节点、以CC2430和MCP2515为核心的Sink节点的软硬件设计和工作流程。通过在某煤矿大巷实验,测得了2.4 GHz频率在井下的传输特性,并确定在巷道中两个无线传感器节点的距离为15 m时,可实时、可靠的监测巷道的环境参数。     

基于CC2431的低功耗网络节点

针对无线传感器网络节点体积小、能耗低、存储和通信能力有限等特点,以ZigBee为基础,提出了一种基于CC2431的低功耗网络节点的设计方案.详细阐述了构成传感器节点的各模块的设计,即采用了CC2431芯片作为核心元件,使用温湿度传感器SHT11进行温湿度数据采集,并给出了节点软件的设计方案.节点的软硬件均采用低功耗设计,经测试证明,该节点运行稳定可靠,具有较高的通信效率,并且符合设计中对低功耗的要求.     

面向氯气安全监测的无线传感器网络系统

基于无线传感器网络特性,应用传感器技术、无线通信技术和计算机技术,提出了面向氯气安全监测的无线传感器网络系统设计方案.系统采用MSP430F149和CC1101芯片为核心,完成了终端节点和中心节点硬件设计、基于星型拓扑结构的通信协议设计以及PC监测中心监测报警软件设计.无线传感器网络可以快速灵活部署,并且成本较低.系统运行稳定,易于扩展,应用前景广阔.     

无线传感网络在煤矿交全监测中的应用

现代化煤矿要求安全生产,在分析煤矿现有的监测、监控系统不足和无线电磁波在井下巷道的传播特性的基础上,提出了以有线网络为主,无线传感网络为补充的煤矿安全信息系统,为煤矿的安全生产提供更为可靠的保障.     

消防人员安全监护系统WSN节点设计

为满足可靠保障消防现场消防员人身安全的要求,研制了消防员安全监测系统生理参数采集节点.节点采用高性价比的CC2430及传感器,实现对消防员生理参数及环境参数进行采集传输以实时监控消防人员的安全.然而节点中各类传感器对电压要求不同以及节点的能耗是影响节点可靠运行及电池使用效率的主要因素.设计了节点供电电源动态管理机制以提升节点的性能.实验结果表明该节点的电池使用效率比未进行电源管理的节点提高了80%.从而节点的性能得到大幅度的提升.     

基于MSP430的楼宇烟雾传感器网络

现代建筑对楼宇火灾报警控制器联网的要求越来越高,利用ZigBee传感器网络技术扩展性强、容错率低、低功耗及低成本的特性,构建了基于ZigBee协议的无线监测网络,以MSP430F149微控制器和CC2430无线通讯收发器为核心的楼宇烟雾传感器节点,实现数据的采集与远程数据转发.通过实际组网测试证明了该系统性能稳定可靠、实时、准确,验证了设计方案的可行性.     

CAN总线在煤矿远程监测系统中的应用

针对传统煤矿监测系统的缺点,提出了一种基于ARM嵌入式系统的CAN总线煤矿分布式远程监测系统。给出了在线监测系统的总体架构,详细介绍了CAN总线智能节点的硬件组成和软件设计流程。系统采用基于ARM7TDMI-S核心的微控制器LPC2292作为煤矿井下监控子站CAN节点的核心,远程用户通过工业以太网访问本地嵌入式Web服务器以获得矿井的安全监测信息,实现了煤矿瓦斯、一氧化碳等参数的在线实时监测与预警。实验结果表明,该监测系统具有体积小、功耗低、运行稳定可靠等优点。     

基于ZigBee技术的博物馆内人员定位系统的研究

基于ZigBee技术的博物馆内人员定位系统为更加便于人们对博物馆的管理和提高管理效率而设计。该系统的硬件平台由CC2431定位模块,CC2430无线收发模块,各种传感器节点及配套设备构建而成,通过TinyOS操作系统来实现。     

基于WSN的井下皮带机打滑保护监测系统设计

为了满足矿井监测监控的需要,设计了一种基于无线传感器网络的皮带打滑保护监测系统,该系统克服了有线传感器网络的局限性,避免了其他无线通信技术高功耗的缺点.以CC2430单片机设计传感器节点,以CC2420和MSP430F149设计sink节点,并给出了硬件设计和软件流程.该系统简单、可靠、经济,具有很好的应用前景.     

无线传感网络在煤矿安全监测中的应用

现代化煤矿要求安全生产,在分析煤矿现有的监测、监控系统不足和无线电磁波在井下巷道的传播特性的基础上,提出了以有线网络为主,无线传感网络为补充的煤矿安全信息系统,为煤矿的安全生产提供更为可靠的保障。     

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.