集成应变传感器的无源超高频标签电路设计

针对现有有线有源应变传感器不适用于固体火箭发动机壳体应变监测的问题,基于UHF RFID(超高频无线射频识别)技术,设计了一款无源超高频应变传感标签.标签通过电磁反向散射方式,收集超高频射频能量为电路供能,同时在标签电路中加入了大容值储能电容,储存经RFID芯片中的倍压整流电路转换成的直流能量.将标签电路分为UHF标签模块、控制模块和应变传感器模块3个部分进行了设计,并通过使用低功耗芯片以及控制测量电路的断开和闭合来减小功耗.标签将传统的电阻式应变测量技术与UHF RFID技术结合在一起,为实现固体火箭发动机壳体应变的无线监测提供了解决方案.     

一种无干扰可配置的后向散射无线传感网络架构

低成本、低功耗是无线传感网络得到普遍应用的重要原因。基于软件无线电技术、LabVIEW和USRP（Universal Software Radio Peripheral）平台,本文提出并实现了一种面向多传感应用、无干扰可配置的后向散射无线传感网络架构原型,架构由可配置零中频接收的后向散射无线传感收发器和传感节点组成,通过无线射频能量获取和传感节点的射频唤醒,有效地降低了系统功耗。论述副载波可配置的频分多址接入方法,给出并证明了避免多传感器接入碰撞的传感数据脉冲周期约束条件。实验和仿真验证了提出架构的有效性和可行性,实验测试误差矢量幅度EVM值小于2.8%,且数值分析和Monte Carlo仿真验证间的中断率误差小于1.86%。     

机动车车速监测的RFID传感标签及其系统设计

为了实现机动车车速的分布式监测以及智能预警,设计了一种基于无线射频识别（RFID）技术的速度监测传感标签和电子管理系统。系统采用车速传感器采集机动车实际行驶速度并送入信号处理单元进行数据处理,传感标签将机动车身份信息、实际速度发送给安装在道路沿线的读写器;各读写器通过网络与电子管理系统进行实时信息交流。实验表明,该系统能准确采集机动车速度信息并实时传输和处理,为高速公路机动车行驾监管提供了一种新的技术方法。     

基于UHF RFID技术的无线脉搏血氧监测系统设计

针对我国人口老龄化和医疗资源紧张问题,设计了一种基于900MHz UHF RFID技术的无线脉搏血氧传感系统.系统整体构架由光电传感器、微处理器、RFID标签、RFID阅读器和上位机组成.光电传感器和微处理器实时采集和处理脉搏血氧信号,RFID标签和阅读器实现数据无线通信,最终通过上位机完成数据收集和界面显示.实验结果表明:所设计系统与临床用血氧检测仪具有良好的一致性,且具有无线传输和低功耗的特点,为无线生物传感芯片的设计开发提供了参考.     

低功耗半主动式水质传感电子标签设计

介绍一种基于射频识别技术和低频唤醒技术的超低功耗水质传感电子标签的硬件和软件设计方案。以MSP430F149单片机作为电子标签的主控芯片,应用AS3933低频唤醒芯片实现对水温、溶解氧、电导率、浊度、PH值等数据的唤醒采集,并通过CC1150无线发射模块实现数据通信。经过实验检测,系统的唤醒距离在3.5m左右,功耗低,工作稳定,通信效果理想。     

基于射频技术的无线智能传感标签设计

针对目前普通电子标签和现有传感标签功能的局限性,设计了一种集射频识别、传感信息采集、物流仓储信息显示于一体的特高频（ UHF）智能传感标签。该标签采用ATmega 328P为控制核心,温湿度传感器SHT10、运动传感器MPU6050为感知器件,LED作为信息显示器件,UHF无源标签芯片UCODE I2 C作为射频信号的收发器,在减少功耗的同时,实现了环境监测、姿态监控和物流操作信息提示。     

基于射频识别技术的出租车防伪管理系统的设计与实现

综合运用2.45GHz有源射频识别(RFID)射频识别技术、信息处理技术、通用分组无线业务(GPRS)通信技术、全球定位系统(GPS)定位技术、移动计算与网络技术,设计了出租车防伪管理系统软硬件架构,开发出2.45GHz有源标签和具有识别、定位导航、移动通信功能于一体的信息终端。同时,在分析系统应用模式的基础上,开发出系统上层应用软件。搭建的应用系统测试结果表明：该系统超低功耗工作,标签峰值电流仅2mA;数据实时性高,传输平均延时小于4s;RFID感知终端有效识读距离达到110m,并能同时识读不少于150个标签。     

珍贵书籍智能检索管理系统

为了实现珍贵图书的智能检索与管理,提出了一个基于无线射频识别技术(RFID)的解决方案。无线识别技术是通过非接触的方式,有效得读取标签相关信息的一个技术。其拥有体积小,识别距离远,安全性高,信息量大等特点。本文针对智能图书检索管理,设计了RFID读写器,能够高效读取图书中所贴标签的信息,并且能够快速检索计算机内相关数据的信息。同时,在此给出了射频识别系统读写器的软硬件设计与流程以及计算机中界面设计与数据库之间的程序设计流程。     

一种低功耗无线传感网络节点的设计

无线传感器网络是物联网的传感层。在无线传感器网络的设计与实现中,低功耗成为系统应用的重要制约,因此设计低功耗节点是当前研究难题之一。在自主研发的基于无线传感网络的智能交通系统中,研究电源功耗问题,设计并制作完成了低功耗无线传感网络节点。     

一种低功耗无线传感网络节点的设计

无线传感器网络是物联网的传感层。在无线传感器网络的设计与实现中,低功耗成为系统应用的重要制约,因此设计低功耗节点是当前研究难题之一。在自主研发的基于无线传感网络的智能交通系统中,研究电源功耗问题,设计并制作完成了低功耗无线传感网络节点。     

Organizing and presenting geospatial tags in location-based augmented reality

Recent improvements in the capabilities of smart phones are making the location-based augmented reality services a reality. When widely used, such a system is expected to produce many user-created geospatial tags concentrated at popular and important sites. In this paper, we describe a way to organize and group such geospatial tags (manually or automatically using a nearest neighbor algorithm) and how to efficiently interact to search and find the tag that the user might be interested in. The proposed method was implemented on an Apple iPhone, and an experiment was carried out to verify the improved usability. The results do indicate the advantage of the principle of hierarchical organization of data. We also further found that the “automatic-but-less-accurate” approach is more suitable than “precise-but-manual” due to the dynamic nature of the mobile interaction and less than perfect sensing.     

An anti‐collision algorithm based on balanced incomplete block design in RFID systems

An important challenge in radio frequency identification (RFID) systems is the collision concern. When an interrogator send a request, it has several tags to answer to in its transmission range, and a tag collision has occurred. The interrogator must be able to recognize tags as rapidly as possible. A collision problem is a power‐consuming occurrence that diminishes the operation of RFID structure. This article proposes a tag anti‐collision power‐clustering RFID algorithm for all tag identification. The tags are boundaries into the several power level clusters based on distances of the reader. Specifically, in the proposed algorithm, tags and readers use of balanced incomplete blocks design (BIBD) to reach a fast identification. In a BIBD matrix, any two columns intersect exactly in one component that makes it possible for easy transmission of any two tags via the tag's identification in their read cycles. The aim of this article is to propose a joint organization that while decreases power consumption increases the working lifetime of RFID structure. The reader can get each tag ID by distinguishing each unit of BIBD symbols, one by one. The use of proposed algorithm brings about a great improvement in the power consumption and identification time.     

Investigation of fabrication and encapsulation processes for a flexible tag microlab

The aim of this paper is to present an integrated process flow for a smart tag with integrated sensors and RFID communication, a flexible tag microlab (FTM). The heart of the designed container tracing system is an RFID system (Reader + Tag) with gas sensing capabilities on board. In the former prototypes, the chemical sensors were integrated on the reader, whereas the tags where addressed like conventional RFID-tags containing also physical (temperature, humidity and light) sensors. However, this paper will show how the gas sensing reader functionalities are being transferred to the tag, reaching a FTM, which represents a real innovation in the field of flexible labels. Key issues for the realisation of the FTM, such us flexible substrates and gas sensor integration technologies will be presented. The process flow employed for the two metal levels interconnect fabrication will be described in detail. The material used is the DuPont? Pyralux^® AP 8525R double-sided copper-clad laminate, formed by a Kapton foil with a copper layer on each side. The vias and windows openings are performed by femtosecond laser ablation. The copper interconnections are realized by photolithography and wet chemical etching. The MOX sensors hotplates specially developed to fulfil the FTM constrains in terms of low power consumption has been used to prove two integration technologies into the flexible substrates: chip on flex (COF) wire bonding and anisotropic conductive adhesive (ACA) flip chip bonding. Both technologies will be compared and benchmarked for future product developments.     

基于无源超高频RFID温度标签的温度监测系统

设计一种基于无源超高频(UHF)射频识别(RFID)温度标签的温度监测系统.系统由课题组自主研发的无源超高频RFID温度标签、Speedway R220商用阅读器和上位机应用软件组成,实现了物品身份识别、温度实时测量和显示的功能.为提高温度标签的测温精度,提出了一种自适应功率匹配算法,使得天线扫描范围内的多个标签都能在最佳测温功率下测温.测试结果表明:当温度标签与阅读器天线的距离分别为0.5,1.0,1.5m时,测温误差小于±1℃.     

一种自适应识别RFID标签的方法

铁路标签分为机车标签和货车标签,两种标签被读写器发射的射频能量激活后,将连续不断、周而复始地返回标签中的数据帧给读写器,但两种标签返回的信号波形是不同的;利用机车标签帧头(特征值为0xE6D)与货车标签帧头(特征值为0x555555A)的不同,可转入不同的解码程序,达到自适应地识别出机车标签数据或货车标签数据;当列车运动时,货车标签返回给读写器的信号受多径效应的影响,出现衰落现象,使读写器不能正确识别标签数据,而且标签信号出现衰落的时间是随机的;利用同步特征信号可以采集到残缺的数据,并利用三帧残缺的数据拼接出一帧完整的标签数据。即使列车速度达到80km/h,也能正确识别出标签数据。     

超高频射频识别湿度传感器的分析与测试

读写器和标签组成的射频识别系统(RFID)可以用于湿度测量.本文通过理论分析,数值仿真以及实验测试给出了可用于湿度传感器的EPC Gen2电子标签的特性.分析结果表明,当湿度变化时,标签天线和标签之间的阻抗匹配系数单调变化的标签才可用做湿度传感器.在空气中,标签天线和标签芯片完全匹配的标签可以用于湿度测量.本文还在实验...     

A fast RFID tag identification algorithm based on counter and stack

Radio frequency identification is a contactless, low power, and low cost wireless communication technology. Like barcode, it can be stuck to a product, animal, instrument and etc.; there are lots of applications being used practically in the real world. During communication, all tags and reader are shared with the same communication channel. The tag collision arbitration is a significant issue for reducing the communication overhead during tag identification. In this paper, we propose a fast tag identification algorithm named as Enhanced Anti-collision Algorithm (EAA). EAA uses counter and stack to reduce tag collisions efficiently. Compared to other existing methods, our method not only uses fewer timeslots but reduce the length of a timeslot for identifying tags.     

基于泛在电力物联网的普适性智能电表状态实时评估方法

针对当前智能电表状态评估存在精确度低、泛化性差和实时困难等问题,本文采用泛在电力物联网构建状态实时评估方法解决该问题。首先,采用决策树算法实现智能电表的分类,整体增强方法的匹配度和适应性;随后针对不同类别的智能电表,采用Apriori算法对样本集数据的特征集进行识别和提取,从而降低特征维度并增强关联性;接着,基于决策引擎实现对智能电表状态实时评估,并以度量学习实现新增物联网采集数据的有效性评估,反馈优化传感设备部署,从而根据评估结果实现对新增部署传感器及其位置的调整,进而根据应用场景不断优化智能电表状态实时评估应用模式。实验结果表明,本方法可实现智能电表运行状况的实时、普适、精准运维评估,进一步解决泛在电力物联网设备现场部署经验不足、校验无目标等问题。