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文献翻译(传感器)

文献翻译(传感器)
文献翻译(传感器)

通过控制传感设备的占空比最小化无线传感器网络的功耗

一种基于ARM传感器定位方法的案例

Kai Lutz and Andreas Konig

Institute of Integrated Sensor Systems

TU Kaiserslautern

67663 Kaiserslautern, Germany

e-mail: koenig@eit.uni-kl.de

摘要:在过去的十年里,无线传感器网络(WSN)已经取得了重大的突破。它为传感器的应用提供了更多的选择,例如从环境智能到农业应用,基于WSN 的测量系统通常是在苛刻的功耗限制条件下工作。尤其因为微机械电子系统的存储元件的能量密度很低,所以WSN的功率消耗少。SWN功耗少的主要原因是由于传感器和传感器设备使用了高度优化的微控制器。WSN试图通过低功耗桥式放大电路的设计方法减少待机电流。相反的是,本文调查了一种通过无缝集成进入微控制器睡眠模式的电桥可控传感和占空比的方法。该电路被用于基于本土化自主WSN的各向异性磁通(AMR)的特定情形,在一个分析放大器电流的系统里,转换速率、开启时间被优化用于三轴ARM传感器的最小功耗参数。在所要求的读出速率,例如,每分钟测量连续操作的因素能量消耗可减少1.5。可控芯片在标准体积为0.35um cmos技术下针对不同类型的传感器和校准需求增加了它的灵活性。

关键字:可控传感器设备;睡眠模式;无线传感器网络;AMR传感器

Ι简介

在过去十年里,WSN在识别、应用和技术方面有了大幅提高。尤其,由于MEMS的集成减少了尺寸和价格以及增加了性能,为新型应用领域提供了解决方案。由于不同类型的传感器,WSN越来越被广泛的应用,比如,从环境智能(Aml)到农业应用。自动WSN应用需要自给自足或在极端低功耗系统下实现基于诸如能量收集和低功耗电路设计的技术。今天的微控制器(MCU),例如,TI的MSP430系列,Atmel的XMEGA 256系列,或能量MICRO的皮质控制器,给它们提供了前所未有的经济操作/睡眠模式,包括模数转换器(ADC)。然而,现有的传感器,电桥,以及所需的放大器,如仪表放大器(InAmp),它们都不包括在该MCU 的睡眠模式设置里。整个传感器节点的功耗主要由电路桥中的纵向电流和传感放大器组成,并且通过传感器,桥和放大器的低功耗设计已经使功耗减到最小限度。相比之下,基于占空比,开关操作放大器和传感电路桥应该被重视。虽然分离电子开关可以作为补救措施,但是由于尺寸和潜在不可预测的电压降它们是不值得推荐的。或者,可以将开关设计概念和电压调节器相结合,例如ADP120,它有许多分立元件,以及印刷电路板调平系统分立元件过多的使用会耗费昂贵的装配且不利于功耗和瞬态行为的优化。一个更有利的普遍做法是在单片机电路离通过电流源控制的手段关断放大器纵向电流,现代的无线传感器节点是由PCB调平系统组装而成,更先进的方式是采用异构组装技术封装芯片或者是将它密封于更密不透风的封装里。弗劳思霍夫协会的电子产品便是一个典型的例子。在这两种情况下,经济实用的芯片已被采用,而在这些芯片中只有少数的芯片具有有效占空比和睡眠模式一体化的功能,并且在某些特定情况下,没有将这些功能与主要配置选项相结合。德克萨斯州仪器和Analog设备支持308/309或8231和8555型号的可编程放大器,他们具有偏移补偿和增益控制配置。不幸的是,这些设备仪器不能的这些功能不能被禁用或者进入睡眠模式状态,同时也无传感器电桥控制这个功能。不过有两个特别的芯片可以实现这一功能,2MD21013MUSIL就是其中的一个种芯片,它可以为带有传感器放大器睡眠操作模式中的传感电桥和ADC 板提供开关电源支持,另一种芯片就是AD8290,它提供了带有传感器放大器睡眠模式的外部可编程电流模式传感器电桥电源。虽然,最后这两个芯片展示了吸引人的特性,但是他们无法对所有相关自动无线传感器节点的设计的挑战进行说

明。额外的配置功能是强制性的,以便为无线传感器网络提供精确、快速和低功率传感器的数据采集。

图1. 无线传感器节点的框图认为在案例研究和M icadot的AMR三轴定位传感器与天线。

在一个案例研究的最开始,是基于无线传感器节点结合磁传感器的设计,在研究项目及相关工业生产自动化的处理中要应用这些设计,它是决定占空比传感器电子最小功率的最佳设计。第二节将概述应用背景和传感器,第三节将呈现系统优化设计界参数和必要配置资源的调查数据,第四节,总结前文,将透露设计细节和所需占空比专用配置传感器电子的意义。

ⅡAMR传感器基于节点定位

在我们的工作中,我们注重具有无线传感器节点的最小功率需求这样的特殊结构,如图一所示

一个带有定电池供电的标准MCU,如已被应用的艾特梅尔Xmega256,它是通过几个传感通道读取数据的,尤其是对无线传感器节点定位这一块,三轴传感器设计就应用了AMR传感器电桥。

图2.低功耗可重构传感器电子

在原型中,AMR桥有一个阻值约为2.5KΩ的电阻,在3V电源的情况下,三轴传感器的三个电桥将会消耗10.8mw的功率。此外三个已被使用的INA122仪表放大器中的任何一个都具有电流约为60uA的静态电流。从而至少导致0.54mw 的功率消耗。假设它的速率为每分钟测量一次,则MCU在省电模式下每分钟将大约消耗3.5uw且在一个固定周期内它的额外配置平均为0.09Uw.

图3. 可重构仪表放大器和相应的模具,其中,虚线表示可重新配置的顺序编程顺序设备领域,通过在码元箭头指示。

因此,该传感器电桥和放大器通过三个以上的数量级主宰整个无线传感器节点的功耗,为最小功耗传感器电子的优化提供需要。有效占空比操作在最小开启时间内通过专用电子器可以有效的解决这些问题,图二展示了期望低功率可配置传感器电子的框图,它包括基于可编程电流的传感器电桥控制和一个读出各个传感器通道的放大器。因此三至六个通道为案例研究呈现的基准。因为本土概念要求快速并发读取三轴传感器中的数据,其不提倡时间复用操作这个功能。

Ⅲ.为占空比传感器电子电力消耗最小化的调查

采用有效设计的方法将睡眠模式、传感器电桥控制以及重要可配置功能相结合。这是我工作目标的追求方式。此前实现了可重构放大器的设计用于可被研究的传感器电子所谓的self-x

图4. 单通道与AMR传感器桥开关电流源,DAC的切换开关和仪表放大器。

该组的前期工作是从演化硬件领域启发,基于大规模晶体管和无源器件领域的数字化可重构传感电子已经得到了开发。

一个动态可重构仪表放大器在0.35um COMS技术下已被设计验证了,这使得它具有固定睡眠模式(MCU控制下关断)和灵活的睡眠模式。通过重新编写计算机程序来降低最低功率从而降低警惕和测量速率。尽管这个概念适用于无线传感器网络可以通过细胞复制进行缩放到多个类似通道该领域功耗是禁止的。因此,在我们最近研究可重构多通道的活动中,推行最小最小芯片同步采集,也就是说可编程资源要被保持到所需的最低限度。同时保持所需的修整、柔韧性和功耗特性。该案例研究注重于系统分析与设计参数的优化,并通过单一传感器电子渠道结合Sensites AFF755BAMR传感器电桥,开关电流源重新配置资源,并切换仪表放大器。还包括数模转换器,如图四所示。该研究是基于奥地利微电子公

司标准的C35B4 0.35um互补金属氧化物半导体(CMOS)2聚酯层/4金属层技术,该技术通常用于工业模拟和混合信号电路中。

图5. 每小时消耗的能量与采样率AMR桥和仪表放大器增加功耗(版本,5pF 的片上载,吨如表给我)。

工作的第一步,要仔细的对传感器通道结构中的放大器的最佳速率和功耗的权衡事项进行探讨。对于这个目的,要将由两个操作放大器结合拓扑米勒组成的仪表放大器给设计一个5PF的片上负载。之后要给放大器输出驱动芯片和片外负载添加一个缓冲器以驱动高达10nF的负载。

表一:不同INAMp版本的功率分析

图五中,在连续和关断操作的情况下,比较了五个设计参数的情形,为了说明占空比操作下能源消耗的趋势,在x轴上用四种常用的采样率表示。曲线包括占空比操作内的电桥能量。从图五上可以明了的看出,该变化最快和最具潜在的功放设计在占空比操作下已经有最佳效果了,对于低阻抗的AMR电桥来说。此外,该规模和电桥供给的电流源的重置范围已经进行了研究。虽然小电流可以允许被用于低功耗电路,但这样将导致有效电桥供电电压V的值变小,Sensties、AFF755B的电桥灵敏度就直接下降到最初值。

图6. 针对以上不同电源有效的桥梁电源电压不同的共源共栅镜像晶体管的宽度

因此,数字配置从50uA到1200uA的更宽范围内是值得推荐的,此外为了补偿因电池失效导致的电压降低,配备一个小的电压源是必要的。

图7. 能源和电力与垂直电流的变化仪表放大器块2.5生病AMR桥。

是通过配置反射率实现的,发射率是由反射晶体管的宽度变化设置的,它控制了放大器中的纵向电流。该偏置电流的上升引起功率消耗的上升,以及改变从系统观察到的动力学属性。例如,在较高的转换速率和较低的稳定时间内,根据特殊应用的要求,放大器一方面可以在一个非常低功耗状态

下操作,其中的测量时间T 是相当长的,另一方面也可以工作在一个高功耗状态下,其中的测量时间是非常快的(小于如图四所示为该电桥的电流源供给图形,它采用了共删源的设计方法,其中该参考电流源自敏感电路。例如PTAT 源,可重构性可以同时被电桥供给的扩展电流使用,因而,有效的电桥供电压也可以减少电源的残留电压,尤其是,该光衰减用电池供给电压以及动态的电源电压下降导致了功率峰值下降,例如,通信芯片,稳定的电流源以及低残留电压是强制性的指标以便正确地读出电桥的斜电压。图六分析了共源共栅源晶体管的宽度为了持续供给800uA的电流就通过降低电源电压的方式。

在我们调查的下一个步骤中,对于一个固定有效电压值为2V的电桥电压(在图中调整过来的M1A/B and M2A/B功率消耗和能源消耗的分析对于单一测量开

启时间T 通过建立标准时间来完成。所以开关相关的瞬态变化都被考虑到能量曲线的计算中,电流变化是通过T)。

适于通用,已经在5kΩ、10kΩ、25kΩ以及50kΩ的情况下重复模拟了电桥,对于不同型号的传感器能耗的相应最小值被表示在表Ⅱ由此可以看在这两极端状态之间,可以找到速度和功耗最佳平衡点的配置。图7中总能量最低消耗点在W=77um处,此刻的偏流为I=1.75mA(W一直保持在20um)

对于较高电阻的传感器,例如,温度传感器pt10k或pt50k,为了出,随着桥电阻的增加,对于又低又慢的功率放大器而言是需要有力的最佳操作。

表2最低能源单耗CONFIGUATION FOR THE不同的桥抗力的案件。

从本节分析中四个可配置定位和认证。这些是,除了普通的增益和偏移调整,桥电源和放大器的偏置电流。前者是为了调整有效的电桥电压为不同的桥电阻以及重新调整在电池的情况下或温度的情况下,与后者在最佳操作状态下就可以实现,数字可编程增加了可配置的可能。如果该最佳操作点由于工业制造容差和应用途中漂移而丢失。

Ⅳ占空比可配置传感器电子电路的设计

如图四所示,该期望传感器电路是由外部电阻桥,可编程电1源以及一个16bitDAC的可配置仪表放大器(图9,10)偏移控制。该基本电路是有【10,11】支持并长占空比操作这些将在以下内容中更详细的给出。大小/重新配置问题将根据上一节的研究情况进行讨论。在所提议的方法中,重新配置需要取消偏置电流,和增益编程,此外电桥供应电流和残留电压可以在一个实际范围内被设置电阻值,电源电压和垂直电流放大器是为了能耗最小化。

图8. 用于可重构桥电流的电流源电路下沉供电和放大器垂直电流。

图8显示了电流配置是如何实现。该PATA的参考电流是通过两个共源共栅电流镜像的,每一个反射镜用来提供I6bit的可重构允许的iBridge和的Ibias 可达到最高1.5毫安。然而晶体管的长度是固定为1um,宽度可以在1um到255um 之间以1um为步长等比例缩小8bit被用于输出镜晶体管(M2和M4),在此电流源范围内,有效电压为3v的电桥传感器的电阻也可以低到2.5kΩ,此外该镜像配置可以被用于调整在电池下降或由于温度变化的电阻的情况下的有效电桥电压,该放大器的偏置电流,也就是用于控制InAmp的1垂直电流,可以以类似的方式重新配置随着偏置电流的增大,放大器速度的上升伴随能耗的增加。在图9所示为仪表放大器所示电路,其增益可设置的范围为5~2000,是由数字可编程

电阻Ra(11bit)实现的。该InAmp设计用于驱动高达10nF的负载电容。因此,一个片外模拟-数字转换器可以进行连接,偏移校正可通过一个16bit的DAC 【11,12】实现,这也是一个占空比,驱动InAmp中的参考管脚偏移校正+/-140mv 是可能的。分别用分层的方法来修剪偏移粗(8位)和FME(8位)的步骤IMV 和101lV的。图10示出了一个详细的运算放大器【10,11】的原理图。除了测量振荡电流的可能性,目前没有深沉配置调备。该规模是为了确保稳定运行变化中的偏移电流,例如,适当的相位度和可控偏移值。

可配置有源和无源器件在原理图中还没详细表述,但是可扩展设备中的期望单元以及串行配置寄存器存在以前的有源元件中。

图9部分可重构仪表原理框图放大器睡眠模式。

Ⅴ结语

在本文中,最小功率的案例研究目前还不能精确测量基于占空比可配置传感器电子基于一个特定的WSN定位AMR传感器应用的无线传感器应用的无线传感器节点的运行在系统调查中,基于标准电路的(拓扑)、重新配置位置和资源已经有了定义。尤其电流的优化和电桥电阻的大小以及微控制器感应负载已经是关注的焦点了。对于AMR电桥和更多的典型桥电阻,最小功率设置和对应的采样时间T 以及放大器转换速率已被设定好了,可配置这功能已被应到偏移、增益,电桥电路以及转换速率控制中去,

所需的能量的比率来计算在第二节和根据由3换算表Ⅱ第一栏所需要的能量频道和每小时60测量和假设sleepmode的1N瓦时的能量消耗3(80pWh * 60 + InWh)/11.35mWh; ::; 1.5.10-6?结果也在

适用于相关的大量电子罗盘的应用,以及作为一个更大范围的电阻传感器。该结果也适用于大量的相关电子应用范围内,以及作为一个范围更宽泛的电阻传感器现在追求的综合性概念,目前现有的商用设备还未对其提供该概念已经用COMS技术在原理图单通道上完成设计了。在接下来的步骤中,完成一个三到六个通道传感器电子芯片的物理设计将继续被执行,包括温度漂移补偿和一个低功率集成翻转电路。由于技术方面的原因。翻译当前设计到一个硅 - 绝缘体(SOL)bipolarCMOS的(的BiCMOS)技术意图。AMR传感器的整合和这里提出的电子传感器是不存在MEMS技术中的。这在随后的工作中将被考虑。

致谢

AMR定位方案的设计信息是由S. Carrella和K. Iswandy

从联邦教育部所办的研究活动以及MST-A VS节目的研究所提供的并由P AC4PTROSIG 16SV3604项目组审核的。

图10. 与运算放大器块的晶体管级示意图省电电路和晶体管伊尔姆纵横比

参考文献

[1]Texas Instruments, Single Supply Auto-Zero Sensor Amplifier with

Programmable Gain and Offset,https://www.wendangku.net/doc/25897928.html,ldocs/prodlfolders/

printlpga308.html,SBOS440A,July 2008,revised April 2009.

[2] ZMDI, MUSic Low Power Multi-Channel Sensor Interface IC,

https://www.wendangku.net/doc/25897928.html,lproducts/sensor-signal-inter faces/zmd21013,Rev

1.3, March 2010.

[3] Analog Devices, Zero Drift, Digitally Programmable Instrumentation

Amplifier, https://www.wendangku.net/doc/25897928.html,lstatic/imported-files/data_sheets/

AD8231.pdf,Rev. A,September 2007.

[4] Analog Devices, G = 50, CMOS Sensor Amplifier with Current

Excitation,https://www.wendangku.net/doc/25897928.html,lstatic/imported-files/data_sheets/

AD8290.pdf,Rev. B,February 2008.

[5] Texas Instruments,V oltage Output Programmable Sensor ConditionerPGA309, https://www.wendangku.net/doc/25897928.html,ldocs/prodlfolders/printlpga309.html,

SBOS292B,december 2003,revised January 2005.

[6] Analog Devices, Digitally Programmable Sensor Signal Zero-Drift

Amplifier,https://www.wendangku.net/doc/25897928.html,lstatic/imported-files/data_sheets/

AD8555.pdf,Rev. A,June 2009.

[7] S. K. Lakshmanan and A. KOnig,"Statistical Analysis of Compensating

Properties of Reconfigurable Analog Circuits for Generic Self-x Sensor

Interface.", Proc. of the 14th Int. Conf. Sensor Conference 2009,

SENSOR+TEST 2009, pp. 263-268, Niimberg, Germany, 26-28 May

2009.

[8] S. Carrella, K. Iswandy, K. Lutz, and A. KOnig, "3D-Localization of

Low-Power Wireless Sensor Nodes Based on AMR-Sensors in

Industrial and AmI Applications", In Tagungsband ITG/GMAFachtagungSensoren und Messsysteme 2010, Niimberg, 18.-19. May,

VDE VerlagGmbH,BerlinOffenbach,pp. 522-529,2010.

[9] Europractice,https://www.wendangku.net/doc/25897928.html,ldocs/austria_datasheets/

035umCMOS_C35_2.pdf (https://www.wendangku.net/doc/25897928.html,).last

visited 25. May 2010.

[10] P. E. Allen, D. R. Holberg, CMOS Analog Circuit Design, Second

Edition,Oxford University Press,New York,2002.

[11] R. 1. Baker, CMOS: Circuit Design, Layout and Simulation, Revised

Second Edition, IEEE Press published by 1. Wiley & Sons Inc.,

Hoboken,New Jersey,2008.

传感器技术论文中英文对照资料外文翻译文献

中英文对照资料外文翻译文献 附件1:外文资料翻译译文 传感器新技术的发展 传感器是一种能将物理量、化学量、生物量等转换成电信号的器件。输出信号有不同形式,如电压、电流、频率、脉冲等,能满足信息传输、处理、记录、显示、控制要求,是自动检测系统和自动控制系统中不可缺少的元件。如果把计算机比作大脑,那么传感器则相当于五官,传感器能正确感受被测量并转换成相应输出量,对系统的质量起决定性作用。自动化程度越高,系统对传感器要求越高。在今天的信息时代里,信息产业包括信息采集、传输、处理三部分,即传感技术、通信技术、计算机技术。现代的计算机技术和通信技术由于超大规模集成电路的飞速发展,而已经充分发达后,不仅对传感器的精度、可靠性、响应速度、获取的信息量要求越来越高,还要求其成本低廉且使用方便。显然传统传感器因功能、特性、体积、成本等已难以满足而逐渐被淘汰。世界许多发达国家都在加快对传感器新技术的研究与开发,并且都已取得极大的突破。如今传感器新技术的发展,主要有以下几个方面: 利用物理现象、化学反应、生物效应作为传感器原理,所以研究发现新现象与新效应是传感器技术发展的重要工作,是研究开发新型传感器的基础。日本夏普公司利用超导技术研制成功高温超导磁性传感器,是传感器技术的重大突破,其灵敏度高,仅次于超导量子干涉器件。它的制造工艺远比超导量子干涉器件简单。可用于磁成像技术,有广泛推广价值。 利用抗体和抗原在电极表面上相遇复合时,会引起电极电位的变化,利用这一现象可制出免疫传感器。用这种抗体制成的免疫传感器可对某生物体内是否有这种抗原作检查。如用肝炎病毒抗体可检查某人是否患有肝炎,起到快速、准确作用。美国加州大学巳研制出这类传感器。 传感器材料是传感器技术的重要基础,由于材料科学进步,人们可制造出各种新型传感器。例如用高分子聚合物薄膜制成温度传感器;光导纤维能制成压力、流量、温度、位移等多种传感器;用陶瓷制成压力传感器。

土木工程外文文献及翻译

本科毕业设计 外文文献及译文 文献、资料题目:Designing Against Fire Of Building 文献、资料来源:国道数据库 文献、资料发表(出版)日期:2008.3.25 院(部):土木工程学院 专业:土木工程 班级:土木辅修091 姓名:武建伟 学号:2008121008 指导教师:周学军、李相云 翻译日期: 20012.6.1

外文文献: Designing Against Fire Of Buliding John Lynch ABSTRACT: This paper considers the design of buildings for fire safety. It is found that fire and the associ- ated effects on buildings is significantly different to other forms of loading such as gravity live loads, wind and earthquakes and their respective effects on the building structure. Fire events are derived from the human activities within buildings or from the malfunction of mechanical and electrical equipment provided within buildings to achieve a serviceable environment. It is therefore possible to directly influence the rate of fire starts within buildings by changing human behaviour, improved maintenance and improved design of mechanical and electrical systems. Furthermore, should a fire develops, it is possible to directly influence the resulting fire severity by the incorporation of fire safety systems such as sprinklers and to provide measures within the building to enable safer egress from the building. The ability to influence the rate of fire starts and the resulting fire severity is unique to the consideration of fire within buildings since other loads such as wind and earthquakes are directly a function of nature. The possible approaches for designing a building for fire safety are presented using an example of a multi-storey building constructed over a railway line. The design of both the transfer structure supporting the building over the railway and the levels above the transfer structure are considered in the context of current regulatory requirements. The principles and assumptions associ- ated with various approaches are discussed. 1 INTRODUCTION Other papers presented in this series consider the design of buildings for gravity loads, wind and earthquakes.The design of buildings against such load effects is to a large extent covered by engineering based standards referenced by the building regulations. This is not the case, to nearly the same extent, in the

无线传感器网络论文中英文资料对照外文翻译

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附件1:外文资料翻译译文 抗侧向荷载的结构体系 常用的结构体系 若已测出荷载量达数千万磅重,那么在高层建筑设计中就没有多少可以进行极其复杂的构思余地了。确实,较好的高层建筑普遍具有构思简单、表现明晰的特点。 这并不是说没有进行宏观构思的余地。实际上,正是因为有了这种宏观的构思,新奇的高层建筑体系才得以发展,可能更重要的是:几年以前才出现的一些新概念在今天的技术中已经变得平常了。 如果忽略一些与建筑材料密切相关的概念不谈,高层建筑里最为常用的结构体系便可分为如下几类: 1.抗弯矩框架。 2.支撑框架,包括偏心支撑框架。 3.剪力墙,包括钢板剪力墙。 4.筒中框架。 5.筒中筒结构。 6.核心交互结构。 7. 框格体系或束筒体系。 特别是由于最近趋向于更复杂的建筑形式,同时也需要增加刚度以抵抗几力和地震力,大多数高层建筑都具有由框架、支撑构架、剪力墙和相关体系相结合而构成的体系。而且,就较高的建筑物而言,大多数都是由交互式构件组成三维陈列。 将这些构件结合起来的方法正是高层建筑设计方法的本质。其结合方式需要在考虑环境、功能和费用后再发展,以便提供促使建筑发展达到新高度的有效结构。这并

不是说富于想象力的结构设计就能够创造出伟大建筑。正相反,有许多例优美的建筑仅得到结构工程师适当的支持就被创造出来了,然而,如果没有天赋甚厚的建筑师的创造力的指导,那么,得以发展的就只能是好的结构,并非是伟大的建筑。无论如何,要想创造出高层建筑真正非凡的设计,两者都需要最好的。 虽然在文献中通常可以见到有关这七种体系的全面性讨论,但是在这里还值得进一步讨论。设计方法的本质贯穿于整个讨论。设计方法的本质贯穿于整个讨论中。 抗弯矩框架 抗弯矩框架也许是低,中高度的建筑中常用的体系,它具有线性水平构件和垂直构件在接头处基本刚接之特点。这种框架用作独立的体系,或者和其他体系结合起来使用,以便提供所需要水平荷载抵抗力。对于较高的高层建筑,可能会发现该本系不宜作为独立体系,这是因为在侧向力的作用下难以调动足够的刚度。 我们可以利用STRESS,STRUDL 或者其他大量合适的计算机程序进行结构分析。所谓的门架法分析或悬臂法分析在当今的技术中无一席之地,由于柱梁节点固有柔性,并且由于初步设计应该力求突出体系的弱点,所以在初析中使用框架的中心距尺寸设计是司空惯的。当然,在设计的后期阶段,实际地评价结点的变形很有必要。 支撑框架 支撑框架实际上刚度比抗弯矩框架强,在高层建筑中也得到更广泛的应用。这种体系以其结点处铰接或则接的线性水平构件、垂直构件和斜撑构件而具特色,它通常与其他体系共同用于较高的建筑,并且作为一种独立的体系用在低、中高度的建筑中。

压力传感器外文翻译

压力传感器 合理进行压力传感器的误差补偿是其应用的关键。压力传感器主要有偏移量误差、灵敏度误差、线性误差和滞后误差,本文将介绍这四种误差产生的机理和对测试结果的影响,同时将介绍为提高测量精度的压力标定方法以及应用实例。 目前市场上传感器种类丰富多样,这使得设计工程师可以选择系统所需的压力传感器。这些传感器既包括最基本的变换器,也包括更为复杂的带有片上电路的高集成度传感器。由于存在这些差异,设计工程师必须尽可能够补偿压力传感器的测量误差,这是保证传感器满足设计和应用要求的重要步骤。在某些情况下,补偿还能提高传感器在应用中的整体性能。 本文以摩托罗拉公司的压力传感器为例,所涉及的概念适用于各种压力传感器的设计应用。 摩托罗拉公司生产的主流压力传感器是一种单片压阻器件,该器件具有 3 类: 1.基本的或未加补偿标定; 2.有标定并进行温度补偿; 3.有标定、补偿和放大。 偏移量、范围标定以及温度补偿均可以通过薄膜电阻网络实现,这种薄膜电阻网络在封装过程中采用激光修正。 该传感器通常与微控制器结合使用,而微控制器的嵌入软件本身建立了传感器数学模型。微控制器读取了输出电压后,通过模数转换器的变换,该模型可以将电压量转换为压力测量值。传感器最简单的数学模型即为传递函数。该模型可在整个标定过程中进行优化,并且模型的成熟度将随标定点的增加而增加。 从计量学的角度看,测量误差具有相当严格的定义:它表征了测量压力与实际压力之间的差异。而通常无法直接得到实际压力,但可以通过采用适当的压力标准加以估计,计量人员通常采用那些精度比被测设备高出至少 10 倍的仪器作为测量标准。 由于未经标定的系统只能使用典型的灵敏度和偏移值将输出电压转换为压 力,测得的压力将产生如图 1 所示的误差。 这种未经标定的初始误差由以下几个部分组成: a.偏移量误差。由于在整个压力范围内垂直偏移保持恒定,因此变换器扩散和激光调节修正的变化将产生偏移量误差。 b.灵敏度误差,产生误差大小与压力成正比。如果设备的灵敏度高于典型值,灵敏度误差将是压力的递增函数(见图 1)。如果灵敏度低于典型值,那么灵敏度误差将是压力的递减函数。该误差的产生原因在于扩散过程的变化。

土木工程类专业英文文献及翻译

PA VEMENT PROBLEMS CAUSED BY COLLAPSIBLE SUBGRADES By Sandra L. Houston,1 Associate Member, ASCE (Reviewed by the Highway Division) ABSTRACT: Problem subgrade materials consisting of collapsible soils are com- mon in arid environments, which have climatic conditions and depositional and weathering processes favorable to their formation. Included herein is a discussion of predictive techniques that use commonly available laboratory equipment and testing methods for obtaining reliable estimates of the volume change for these problem soils. A method for predicting relevant stresses and corresponding collapse strains for typical pavement subgrades is presented. Relatively simple methods of evaluating potential volume change, based on results of familiar laboratory tests, are used. INTRODUCTION When a soil is given free access to water, it may decrease in volume, increase in volume, or do nothing. A soil that increases in volume is called a swelling or expansive soil, and a soil that decreases in volume is called a collapsible soil. The amount of volume change that occurs depends on the soil type and structure, the initial soil density, the imposed stress state, and the degree and extent of wetting. Subgrade materials comprised of soils that change volume upon wetting have caused distress to highways since the be- ginning of the professional practice and have cost many millions of dollars in roadway repairs. The prediction of the volume changes that may occur in the field is the first step in making an economic decision for dealing with these problem subgrade materials. Each project will have different design considerations, economic con- straints, and risk factors that will have to be taken into account. However, with a reliable method for making volume change predictions, the best design relative to the subgrade soils becomes a matter of economic comparison, and a much more rational design approach may be made. For example, typical techniques for dealing with expansive clays include: (1) In situ treatments with substances such as lime, cement, or fly-ash; (2) seepage barriers and/ or drainage systems; or (3) a computing of the serviceability loss and a mod- ification of the design to "accept" the anticipated expansion. In order to make the most economical decision, the amount of volume change (especially non- uniform volume change) must be accurately estimated, and the degree of road roughness evaluated from these data. Similarly, alternative design techniques are available for any roadway problem. The emphasis here will be placed on presenting economical and simple methods for: (1) Determining whether the subgrade materials are collapsible; and (2) estimating the amount of volume change that is likely to occur in the 'Asst. Prof., Ctr. for Advanced Res. in Transp., Arizona State Univ., Tempe, AZ 85287. Note. Discussion open until April 1, 1989. To extend the closing date one month,

传感器外文翻译

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建筑外文文献及翻译

外文原文 Study on Human Resource Allocation in Multi-Project Based on the Priority and the Cost of Projects Lin Jingjing , Zhou Guohua SchoolofEconomics and management, Southwest Jiao tong University ,610031 ,China Abstract----This paper put forward the a ffecting factors of project’s priority. which is introduced into a multi-objective optimization model for human resource allocation in multi-project environment . The objectives of the model were the minimum cost loss due to the delay of the time limit of the projects and the minimum delay of the project with the highest priority .Then a Genetic Algorithm to solve the model was introduced. Finally, a numerical example was used to testify the feasibility of the model and the algorithm. Index Terms—Genetic Algorithm, Human Resource Allocation, Multi-project’s project’s priority . 1.INTRODUCTION More and more enterprises are facing the challenge of multi-project management, which has been the focus among researches on project management. In multi-project environment ,the share are competition of resources such as capital , time and human resources often occur .Therefore , it’s critical to schedule projects in order to satisfy the different resource demands and to shorten the projects’ duration time with resources constrained ,as in [1].For many enterprises ,the human resources are the most precious asset .So enterprises should reasonably and effectively allocate each resource , especially the human resource ,in order to shorten the time and cost of projects and to increase the benefits .Some literatures have

传感器技术外文文献及中文翻译

Sensor technology A sensor is a device which produces a signal in response to its detecting or measuring a property ,such as position , force , torque , pressure , temperature , humidity , speed , acceleration , or vibration .Traditionally ,sensors (such as actuators and switches )have been used to set limits on the performance of machines .Common examples are (a) stops on machine tools to restrict work table movements ,(b) pressure and temperature gages with automatics shut-off features , and (c) governors on engines to prevent excessive speed of operation . Sensor technology has become an important aspect of manufacturing processes and systems .It is essential for proper data acquisition and for the monitoring , communication , and computer control of machines and systems . Because they convert one quantity to another , sensors often are referred to as transducers .Analog sensors produce a signal , such as voltage ,which is proportional to the measured quantity .Digital sensors have numeric or digital outputs that can be transferred to computers directly .Analog-to-coverter(ADC) is available for interfacing analog sensors with computers . Classifications of Sensors Sensors that are of interest in manufacturing may be classified generally as follows: Machanical sensors measure such as quantities as positions ,shape ,velocity ,force ,torque , pressure , vibration , strain , and mass . Electrical sensors measure voltage , current , charge , and conductivity . Magnetic sensors measure magnetic field ,flux , and permeablity . Thermal sensors measure temperature , flux ,conductivity , and special heat . Other types are acoustic , ultrasonic , chemical , optical , radiation , laser ,and fiber-optic . Depending on its application , a sensor may consist of metallic , nonmetallic , organic , or inorganic materials , as well as fluids ,gases ,plasmas , or semiconductors .Using the special characteristics of these materials , sensors covert the quantity or property measured to analog or digital output. The operation of an ordinary mercury thermometer , for example , is based on the difference between the thermal expansion of mercury and that of glass. Similarly , a machine part , a physical obstruction , or barrier in a space can be detected by breaking the beam of light when sensed by a photoelectric cell . A proximity sensor ( which senses and measures the distance between it and an object or a moving member of a machine ) can be based on acoustics , magnetism , capacitance , or optics . Other actuators contact the object and take appropriate action ( usually by electromechanical means ) . Sensors are essential to the conduct of intelligent robots , and are being developed with capabilities that resemble those of humans ( smart sensors , see the following ). This is America, the development of such a surgery Lin Bai an example, through the screen, through a remote control operator to control another manipulator, through the realization of the right abdominal surgery A few years ago our country the

土木工程专业外文文献及翻译

( 二 〇 一 二 年 六 月 外文文献及翻译 题 目: About Buiding on the Structure Design 学生姓名: 学 院:土木工程学院 系 别:建筑工程系 专 业:土木工程(建筑工程方向) 班 级:土木08-4班 指导教师:

英文原文: Building construction concrete crack of prevention and processing Abstract The crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure. Keyword:Concrete crack prevention processing Foreword Concrete's ising 1 kind is anticipate by the freestone bone, cement, water and other mixture but formation of the in addition material of quality brittleness not and all material.Because the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole, spirit cave and tiny crack, is exactly because these beginning start blemish of existence just make the concrete present one some not and all the characteristic of quality.The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other use function not a creation to endanger.But after the concrete be subjected to lotus carry, difference in temperature etc. function, tiny crack would continuously of expand with connect, end formation we can see without the

土木工程外文文献及翻译

Original Article Impact of crack width on bond: confined and unconfine d rebar David https://www.wendangku.net/doc/25897928.html,w1, Denglei Tang2, Thoma s K. C.Molyneaux3 and Rebecca Gravina3 (1)School of the Built Environment, Heriot Watt University, Edinburgh, EH14 4AS, UK (2)VicRoads, Melbourne, VIC, Australia (3)School of Civil, Environmental and Chemical Engineering, RMIT University, Melbourne, VIC, 3000, Australia David W. Law Email: https://www.wendangku.net/doc/25897928.html,w@https://www.wendangku.net/doc/25897928.html, Received: 14January2010Accepted: 14Decemb er2010Published online: 23December2010 Abstract This paper reports the results of a research project comp aring the effect of surface crack width and degree of corrosi on on the bond strength of confined and unconfined deforme d 12 and 16mm mild steel reinforcing bars. The corrosion was induced by chloride contamination of the concrete and

传感器外文文献

Photoelectric sensor Key word:photoeletric effect photoelectric element photoeletric sensor classification sensor application characteristics. Abstract:in the development of science and technology in the modern society,mankind has into rapidly changing information era,people in daily life,the production process,rely mainly on the detection of information technology by acquiring,screening and transmission,to achieve the brake control,automation adjustment,at present our country has put detection techniques listed in one of the priority to the development of science and technology.Because ofmicroelectronics technology,photoelectric semiconductor technology,optical fiber technology and grating technical development makes the application of the photoelectric sensor is growing .The sensor has simple structure, non-contact,high reliability,high precision,measurable parameters and quick response and more simple structure,form etc,and flexible in automatic detection technology,it has been widely applied in photoelectric effect as the theoretical basis,the device by photoelectric material composition. T ext: First,theoretical foundation-photoelectric effect Photoelectric effect generally have the photoelectric effect,

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