CAN总线在电梯中的应用

分析了CAN总线的一些特点以及在电梯控制系统中的应用和发展状况，提出引入国际上通用的CAN总线高层应用协议，规范国内CAN总线的使用．用以提高电梯控制系统中CAN系统通信协议应用的兼容性和通用性，并简要介绍了一种CAN的高层协议——CAN0pen协议。     

CAN网络在汽车上的应用分析

随着现代汽车的不断发展,汽车电子设备不断增加,汽车综合性控制系统控制信号需实时交换。CAN是控制器局域网, CAN总线的数据通信具有突出的可靠性,灵活性特点,由于其良好的性能,汽车领域广泛的应用CAN总线实现汽车内部控制系统的数据通信,本文重点详细介绍CAN总线在汽车上的应用。介绍了车身控制系统结构,可作为我国汽车企业自主开发CAN总线控制系统有益探索。     

CAN总线在消防产品中的应用

介绍CAN总线;给出CAN总线在消防产品中的应用方法、部分节点电路原理图。     

CAN总线通讯架构在客房控制系统中的应用

本文介绍7CAN总线的优越性及其在客房控制系统中的应用,阐述7CAN总线网络在酒店客房控制系统中取代其他总线结构已经成为趋势,CAN总线结构的客房控制系统也将是客房控制系统未来发展的方向。     

基于CAN总线的门禁系统设计与实现

针对目前国内门禁市场新的需求和未来门禁控制系统的发展趋势，同时结合目前国内的实际技术和应用水平，本文提出了一套基于CAN的智能门禁控制系统解决方案。完成基于CAN总线的门禁系统总体结构的设计，对整个系统的功能模块进行设计。对CAN智能节点功能进行设计，从软硬件两个方面介绍CAN智能节点的设计，给出CAN智能节点硬件设计方案，从CAN总线的技术特点对参数进行分析。     

利用CAN总线实现远程输入输出

介绍了CAN总线特点及通讯介质访问方式及远程10在电梯和自动扶梯中的应用。同时详细论述了利用CAN总线实现远程10的理论计算、组成结构及通讯策略，也给出了基于SJA1000芯片的具体的实现电路及在电路中CAN总线接口抗干扰的方法。     

CAN总线多点温度采集节点硬件设计

随着科学技术的发展,温度监控系统的应用越来越广泛,本文阐述了一种基于CAN总线的多点温度采集系统,可以实现温度实时监测,该系统能应用于工农业生产的诸多场合。系统以AT89C52单片机为微处理器,外接数字式温度传感器DS18B20获得现场环境的温度信号。通过CAN总线控制器SJA1000和CAN总线驱动器PCA82C250将数据发送到CAN总线上,从而实现对温度的采集。     

智能混凝土搅拌站称重仪表

自主开发的基于CAN现场总线的智能混凝土搅拌站称重仪表由显示控制模块和传感器数据采集模块组成,模块之间由CAN总线连接,为增强CAN总线节点的抗干扰能力,CAN总线控制器SJA1000并不是直接和CAN收发器.A82C250相连,而是通过高速光耦6N137后与之相连,使总线上各CAN节点间电气隔离;同时,在电源部分采用了DC-DC模块B0505LS给光耦6N137右边模拟电路供电,采用不同的电源供电,光耦6N137两边电路完全隔离,提高了模块的稳定性.新型称重仪表的软件包括数据采集程序和显示控制程序两部分,分别安装在传感器数据采集模块和显示控制模块内.基于CAN现场总线的智能混凝土搅拌站称重仪表的准确度达到国家Ⅲ级标准,CAN通讯波特率可达250 kB/s;该新型仪表已取得了国家相关技术专利和器量型具批量生产许可证书,目前已经批量应用于三一集团的混凝土搅拌站.     

数据挖掘技术在控制器局域网总线中的应用研究

提出了数据挖掘技术在汽车控制器局域网(CAN)总线通信数据中的应用。汽车中的各种电子控制系统通过CAN总线相互连接通信,其中产生的大量报文被存储在日志文件中。首先对CAN总线日志文件的中大量通信数据做预处理,再扩展使用关联分析、分类及聚类分析等方法对处理过的数据进行挖掘,从而找到各条报文之间及报文内部各位或字节之间可能存在的新规律或者关系,为进一步研究CAN总线系统连接的各个控制系统之间的通信提供了帮助。     

AT90CAN128的CAN中断机制探讨

AT90CAN128内部集成的CAN控制器兼容CAN2.0A和CAN2.0B标准,具有较高的性价比,但其内部结构和中断机制与独立的CAN控制器不同.为探讨AT90CAN128独具特色的CAN中断机制,从AT90CAN128的CAN模块结构入手,阐述了其采用15个Mob进行数据的接收和发送的原理,进而分析了两个软件上的中断CANIT和OVRIT,他们分别对应不同的硬件中断源、中断触发方式和中断处理方式.最后设计了相关的CAN中断试验,试验结果证实了相关分析的正确性.     

Magnetoelastische Spannkraftmessung in Bauwerken

Magnetoelastic Measurement of Prestressing Force in Civil Structures The knowledge of the tensile force of prestressing steel elements and its reliable and non‐destructive determination are of essential importance for the assessment of the structural health condition of prestressed concrete structures and tie‐back systems in terms of structural safety, serviceability and durability. For the evaluation of the prestressing force in steel tension members, the measurement technique presented in this contribution is using the magneto‐elastic effect (ME‐effect) of ferromagnetic materials. This effect describes the reverse‐proportional correlation between the mechanical stress and the magnetic properties of ferromagnetic materials. The cylindrical coiled sensors pushed over the tendon and the measuring device developed and practically optimized at the iBMB/MPA of the TU Braunschweig enable a fast and reliable measurement of the prestressing steel force after an initial calibration. In this contribution first the state of the art of prestress measurement techniques for steel tension members is presented. Afterwards, the ME‐measuring method with the basics and merits of magneto‐elastic prestressing force identification is shown. Further recent research results as well as several building applications will be discussed.     

土体干缩裂隙的形成发育过程及机理

土体干缩开裂(龟裂)是一种常见的自然现象,龟裂的产生会破坏土体的完整性,极大地弱化土体的工程性质。基于室内试验结果,发现龟裂发育过程可分为3个典型阶段,具有很强的时序特征,且新生裂隙一般垂直已有裂隙生长。根据水土相互作用原理和基本土力学理论,建立了土体龟裂概念模型,对实验室和自然界中观测到的相关龟裂现象及其机理进行了分析,得到如下主要结论:(1)土体中存在收缩变形空间是龟裂发育的前提,主要与土质条件有关;(2)龟裂是土体发生张拉破坏的表现形式,孔隙水的表面张力及干燥过程中引起的基质吸力(毛细水作用力)会在土体中形成张拉应力场,这是导致龟裂的主要力学诱因;(3)当张拉应力场的大小超过土体的抗拉强度或土颗粒间的联接强度时,裂隙便会产生,导致局部区域积聚的应变能释放,应力场重新调整。从宏观上看,基质吸力和抗拉强度是控制龟裂发育的两个关键力学指标,但从微观上看,土体材料尤其是结构的非均质性对裂隙发育过程和裂隙网络的几何形态特征均有重要影响。通常情况下,大部分裂隙都是在饱和阶段产生,且裂隙产生时对应的临界含水率有可能高于液限;土体表面上的"杂点"易导致应力集中,裂隙往往率先在"杂点"处产生;(4)受表面和裂隙面张拉应力场的共同作用,表层土体边缘会发生向上卷曲变形,产生"煎饼效应"。此外,土体在收缩过程中还存在收缩核现象。     

Zustandsuntersuchung und Instandsetzung am Hauptdach des Hauses der Kulturen der Welt in Berlin

The main roof of the ”Haus der Kulturen der Welt“ in Berlin Which is very well‐known on account of its history and striking structural design – was to be inspected by the author to determine its condition and analysed with regard to the durability of the existing liquid synthetic sealant. The roof structure consists of a biaxial, curved area‐covering structural element with circumferential edge beams of pre‐stressed lightweight concrete. This is the result of the reconstruction between 1984 and 1987 following a partial collapse of the then Berlin Congress Hall in 1980. The very thin roof shell is also made of lightweight concrete and, like the edge beams, has a polyurethane‐based spray‐on seal that was specially developed for this purpose as protection against the ingress of moisture. The reason why this, at the time, novel type of seal was chosen was that it should take into account the fact that the roof design urgently needed some kind of protection against moisture that had to compensate the expected changes shape and crack movements of the roof with no damage. The following article reports on the nature, scope and main results of the analysis of the condition of the roof seal, edge beams and abutments. It will also describe the repair recommendations resulting from the investigations, which form the basis of the execution of work at the present point in time. Apart from presenting the technical principles and special features of the building that have to be taken into account during any repairs, the special features of the execution will also be addressed.     

Alternative Methods of Procurement for Works of Water and Environmental Management

The paper considers methods of procurement for the construction of water- and sewage-treatment works other than the traditional use of the ICE 5th Edition Conditions of Contract and Bills of Quantities. This is as a consequence of the speed at which schemes are currently required within the water industry.
The paper particularly focuses on the use of target contracts, using the Institution of Chemical Engineers'Green Book form, and considers various types of target. It also discusses the form which tender documents may take, and how targets may be calculated.
Tendering procedures, including the use of two-stage tenders and negotiated targets, are considered, as are the procedures for cost monitoring and the financial management of the contract. Finally, the role of the engineer and quantity surveyor is considered.     

Innovative technique for identification of prestressing tendons layout in post-tensioned bridges using a probe with MEMS accelerometer

Post-tensioned concrete bridges are currently often constructed engineering structures. In this type of bridges it is crucial that geometrical layout of prestressing system complies with the design requirements. Unfortunately, major errors still occur during assembly of tendon routes. This has often negative effects. In a local aspect, it may cause a local damage, such as spalling of concrete cover. In a global aspect, prestressing may produce distribution of forces in the bridge structure different from the expected. That is why numerous methods have been developed to control the accuracy of executed tendon routs. Some of them, e.g. geodetic measurements with levelers, require direct access to tendon sheaths. Other methods, which can be used after casting of concrete (mainly NDT methods) have a series of resolution, efficiency and accessibility limitations. Hence, the paper presents a proposal of an alternative method for control of tendons routing using a special probe with Micro Electro-Mechanical Systems capacitive accelerometer. The paper presents a concept of tests performed with the probe, evaluation of the probe application in the view of a random process and finally assessment of the results obtained with the use of the constructed measurement system in trial laboratory conditions.     

A Survey of Ferruginous Minewater Impacts in the Welsh Coalfields

The aim of this study was to locate all ferruginous discharges within the Welsh coalfield areas and to assess their impact upon receiving watercourses. The project was undertaken in two stages. In the first stage, visual assessments were carried out on an area of river bed affected by iron hydroxide deposition. Chemical samples of the discharges and the receiving watercourse were analysed for a suite of physico-chemical determinands. Ninety discharges were located impacting upon 59.4 km of river, and an area of 22 ha was affected by iron hydroxide deposits.
A ranking method, incorporating the physical/chemical determinands, was developed to assess the comparative impact which discharges were having on receiving watercourses. A total of 33 of the top ranked discharges- (20 to classified watercourses and 13 to unclassified watercourses) having the highest environmental impact were selected; chemical, biological and fisheries impact assessments were then carried out on these discharges in the second stage of the project. The sites were then ranked on the basis of biological and fisheries impact. A list of the highest impacted sites was produced, and some of these were further investigated for remediation options and associated costs.     

Umfangreicher Validierungsdatensatz eines großen Verwaltungsgebäudes für Software zur DIN V 18599

Detailed Data Set of a Large Administration Building as a Validation Model for DIN V18599‐Software. The calculation method of DIN V 18599 represents a very complex model for the estimation of the energy efficiency of buildings. The method is used for certificates too, thus, the number of users is quite high. This fact and the complexity of the method causes high demands on the related software products. Most of the end user software tools work with the calculation engine ibp18599kernel developed by Fraunhofer‐Institut for Building Physics. There is a continuous quality control for both, the kernel and the user interfaces, i.e. the end user software. This paper gives an overview of the process of quality control as well as a documentation of a validation model used within this process, i.e. a complex administration building as a sample.     

约束受热伸长中空柱填充混凝土的耐火性能

在圆形中空柱中填充混凝土是一种很好的柱子加固方案,因为它能够增加柱子在室内和高温环境下的承载能力。然而,发生火灾时,对受热伸长的约束可能会改变其力学性能。通过对约束受热伸长中空柱进行一系列耐火试验后,得出试验结果。试验对柱子长细比﹑承载等级﹑周围结构刚度以及所占钢筋的百分比和混凝土强度等参数进行了测定。结果显示,这些柱子的极限抗火时间都小于46min。在柱子内层墙面使用混凝土环,从其性能上来讲在火灾时并没有太大优势,因为混凝土环会受到钢管过热而带来的大面积碎裂。柱子最主要的破坏方式即是整体屈曲。然而,在一些试验样本上也出现了局部屈曲。     

Reliability of composite steel bridge beams designed following AASHTO''s LFD and LRFD specifications

Composite steel beam bridges designed following AASHTO's Load Factor Design (LFD) method and the newly developed Load and Resistance Factor Design method (LRFD) are proportioned for different loading conditions. They need to satisfy these conditions at maximum design load, an overloading condition, and fatigue load. The ultimate strength of compact composite steel beams is based on the fully plastic stress distribution. The capacity of non-compact beams is based on the yield or partially-plastic moment, depending on whether the beam violates all or few of the compactness or ductility requirements. In this paper, the reliability for the ultimate flexural capacity limit state of composite steel beams is investigated. The structural reliability is measured in terms of the reliability index. The statistical data on strength are generated starting from statistics on material properties and using the Monte Carlo simulation method. Statistical data on load components are compiled from the available literature. The scope of the study covers a wide range of rolled beams, span lengths, beam spacings, and two yield strengths. The deterministic study showed that the design of composite steel beams is usually not governed by the maximum design load combination, but rather by the overloading condition. The results of the reliability study indicate non-uniformity in the safety of steel bridges that are designed by the AASHTO LFD code. This is also true for AASHTO's LRFD code since it is not calibrated for the overloading condition. The value of the reliability index is a function of the compactness classification, method of design, beam spacing, span length, and section size.     

Application of sonic and radar tests on the piers and walls of the Cathedral of Noto

The authors applied systematically sonic tests, radar tests and other diagnostic techniques on the remaining walls and piers of the Cathedral of Noto. The experimental survey was carried out by the Laboratory of the DIS, Politecnico of Milan (Person in Charge: Prof. Binda, Prof. Baronio) in collaboration with the designers (Ing. R. De Benedictis, Arch. S. Tringali) and the experts working on the reconstruction. The Prefettura of Siracusa founded the research. The right aisle and most of the dome of the Cathedral collapsed in 1996. The aim of the research was to verify the state of damage and the possibility of conservation of the walls and piers in view of the reconstruction of the damaged part of the Cathedral. Furthermore, the sonic tests were used to control the effect of grout injection used as a possible technique for repair of the damaged masonry (Proceedings of the Conference on Nondestructive Evaluation of Civil Structures and Materials, Boulder, Colorado; (1992) 329; Proceedings of the Sixth Conference on Structural Faults and Repair, 3 (1995) 195). In the following the results will be reported and the reliability of the tests will be discussed as it was confirmed by the use of other complementary diagnosis techniques (Proceedings of the Sixth International Conference on Structural Studies, Repairs and Maintenance of Historical Buildings, STREMAH 99, Dresden, Germany, (1999) 323).