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关键词： RFID tags   Modulation   Antenna measurements   Power transmission   Semiconductor device measurement   Sensitivity   Integrated circuits   UHF-RFID   RFID tag characterization   chip sensitivity   RFID power profiles   read range   multipath   channel reciprocity  

摘要： This paper presents a detailed characterization of passive UHF-RFID tags using measured power activation profiles. Factors such as chip sensitivity, antenna dimension, and conjugate impedance matching are taken into account. Results are presented in a proposed chart relating the square root of the modulation factor to the mean power transmission coefficient, providing a fine-grained comparison of tag performance. The free space read range of tags is then investigated as a function of mean transmission coefficient, modulation factor, chip and reader sensitivity. The approach is illustrated and validated through a measurement campaign on a set of 9 commercial tags. The proposed characterization procedure enables an accurate assessment of tag performance.

关键词： RFID天线阵列   读写器   电子标签   定位跟踪   生物遥测  

摘要： 小鼠因为容易饲养且与人类生理病理相似,经常被用作药物研究的实验对象。监测其用药后的活动轨迹和生理参数变化有助于药物的优化和开发。传统定位跟踪技术定位跟踪小鼠时会因其活动范围小、外观相似度高而导致跟踪准确性下降,卫星遥测技术因成本高且需要专门的接收站进行数据处理,仅适用于大范围活动的动物的生理参数监测。为了长期监测小鼠用药后的活动轨迹和生理参数变化,本文提出并设计了基于RFID技术的笼内小鼠定位跟踪及生理参数监测系统,具体内容如下:首先针对小鼠活动轨迹的测量设计了定位跟踪系统,该系统由读写器多天线阵列板、多天线选择板、多天线控制板和上位机软件组成。考虑到小鼠体积大小,对天线阵列板的天线单元格建立了天线模型,在分析相关参数对天线等效电感的影响后,确定了单元格尺寸为45x45mm,加入天线匹配电路后,天线单元格内部有较为均匀的磁场分布。在设计了合理的天线间距后,通过验证,系统可以准确定位标签位置。为了减少潜在的天线阵列效应和能量浪费,设计了多天线选择板,该板可以通过控制时序和射频信号来控制每个天线单元格。通过多天线控制板中时序信号定时器时间的设置以及天线选择板中相关芯片的选择,使得两个连续的天线单元格之间的切换时间间隔小于25ms,保证了天线单元格在小鼠经过期间能够识别其体内标签。其次,针对小鼠生理参数的监测设计了生理参数监测系统,该系统由无线能量传输模块、植入式电子标签、RFID读写器和上位机软件组成。无线能量传输模块体外部分由读写器天线连接板组成,采用多匝矩形线圈绕在小鼠饲养笼周围的方式为植入式电子标签进行供电;体内部分主要由植入式电子标签天线及其谐振电路组成,标签不装载电池。考虑到用药后小鼠体温和活动量这两个参数变化最为明显,标签集成了相应传感器以测量上述参数。为了减轻标签对小鼠的负担,标签设计过程中全程采用微型化结构,整体尺寸仅为20x10x2mm,比一角硬币还要小。最后,在完成系统搭建后进行了模拟实验和生物实验。在模拟实验中,分别验证了定位跟踪系统中单个天线单元格读取标签的能力,以及生理参数监测系统中植入式电子标签测温性能以及测量活动量性能,模拟实验证明了系统性能的可行性,为生物实验提供了理论基础。在生物实验中,选用2只15g左右小亚成小鼠作为实验对象,对小鼠使用一定剂量的麻醉药后进行植入手术,实时跟踪显示了两只小鼠5分钟内的活动轨迹,小鼠在前1-2分钟处于相互远离的状态,随着时间的推移,两只小鼠快速且频繁地进行交互。随后进行长达10分钟的生理参数监测实验,结果显示,小鼠因麻醉药效而在监测全程中体温偏低且没有剧烈的活动行为,体温范围为34.5-35.5℃,活动量大部分均低于15mg/LSB。为了更好地研究麻醉药对小鼠的影响,又持续观察了小鼠3小时的体温变化,在实验进行的一个半小时左右后,小鼠体温逐渐升高,恢复至37℃左右,属于小鼠正常体温。实验证明,系统能够实时显示小鼠活动轨迹,并测得有效的体温和活动量。

关键词： ISO/IEC 18000-6C   UHF RFID   标签   SoC   RISC-Ⅴ   FPGA  

摘要： 射频识别技术(Radio Frequency Identification,RFID)是通过发射和接收射频信号的方式与记录媒体进行非接触性双向通信,对目标对象进行识别并获取目标对象的相关参数的技术。其中,超高频射频识别技术(Ultra High Frequency Radio Frequency Identification,UHF RFID)以其独特的高传输速率和长目标识别距离等优点被应用于越来越多的领域。以软硬件结合的SoC形式实现UHF RFID系统能够更加快速地适应各种应用需求,具有工程应用价值。 本文基于ISO/IEC 18000-6C协议,设计了一款集成了UHF RFID标签数字基带的SoC系统,整个SoC系统设计包括UHF RFID标签数字基带设计和SoC系统设计两大部分。在UHF RFID标签数字基带部分的设计中,包括标签物理链路和标签识别层两部分。为了兼顾物理链路层的效率和识别层的灵活性,本文通过采用RISC-Ⅴ SoC系统以软硬件结合的方式实现了ISO/IEC18000-6C协议规定的UHF RFID标签的数字基带功能。标签物理链路设计由发送链路和接收链路两部分组成,包括FM0/Miller编码、PIE解码、CRC校验码和前导码检测/添加等功能模块。为保证高效率,论文通过Verilog语言设计的专用硬件实现该部分功能。标签识别层通过软硬件协同设计实现,论文根据阅读器发送指令是否需要访问标签存储区进行了软硬件划分。硬件部分通过Verilog语言设计了包括数据解析、标签状态控制和标签控制等功能模块,软件设计部分通过内核进行处理,这样可以通过软件更新实现算法的升级、UHF RFID标签识别层的定制设计或者协议的升级。在SoC系统设计中,选用了基于RISC-Ⅴ的开源内核蜂鸟E203作为处理器内核,将UHF RFID标签数字基带以外设的方式通过ICB总线与内核连接,并通过添加中断,复用GPIO等方式完成了整个UHF RFID标签SoC的总体设计。本文采用基于IP的SoC设计便于进行系统扩展,可以通过加入其它IP或外围设备实现多功能UHF RFID标签设计。 最终,整个SoC系统设计通过Vivado平台进行综合后,下载到ZYNQ-7 ZC706 FPGA开发板上,并在其上完成了整个SoC系统设计的功能验证。

关键词： Radio frequency identification   RFID   robot tracking   global localization   synthetic aperture   nonlinear optimization   phase unwrapping   robotics   odometry  

摘要： This work addresses the problem of the global localization of a mobile robot by exploiting RFID technology. The robot is equipped with kinematic sensors capable of measuring the incremental distances covered by each wheel and an RFID reader which measures the phase of the signal that is backscattered by reference RFID tags situated inside the environment at known positions. The motion of the robot with respect to the tags enables the collection of measurements from multiple antenna-locations, in a synthetic-aperture sense. Localization of the mobile robot over time is accomplished by processing short segments of trajectory during each iteration. The odometry-data are exploited to estimate each segment of the vehicle's trajectory relative to an unknown initial position. The odometry-based estimation, the known positions of the reference tags, the unwrapped phase measurements and a phase-to-distance model represent the input to a data-fit problem, the solution of which reveals the unknown initial position and orientation of the trajectory segment in the absolute frame. Thanks to phase unwrapping, the data-fit problem features convexity-type properties and the solution is rapidly found by non-linear optimization techniques. The influence of different algorithmic features on the performance of the method is investigated in a simulative context. An experimental campaign that employs a prototype robotic agent equipped with two antennas reports a mean absolute localization error of less than 0.1m, while the execution time stays below the measurements' collection-time such that the real-time capability of the method is preserved.

关键词： 剧毒危险化学品   RFID技术   室内定位   算法优化  

摘要： 剧毒危险化学品是一类具有剧烈的急性毒性危害的如人工合成的化学品、混合物以及天然毒素。此外,那些具有急性毒性,容易导致公共安全危害的化学品也属于剧毒危险化学品之列。在实验室使用过程中的剧毒危险化学品通常量少种类多,难以落实“五双”制度,即“双人保管、双把锁、双本账、双人领取、双人使用”的管理制度。如何实现对剧毒危险化学品的精准管理,规范实验室内对剧毒危险化学品的使用是一个值得探究的问题。物联网技术的发展让自动化、智能化的有效管控成为可能。本项目结合实验室的实际需求,利用射频识别技术(Radio Frequency I dentification,RFID)、数据库等计算机技术,设计开发了一种剧毒危险化学品定位管理系统,实现剧毒危险化学品在实验室内的轨迹追溯和精准管理。论文具体内容如下: 1.首先是对实验室危险化学品信息管理系统进行了详细的调研分析,总结出目前大工业环境下“万物互联”的发展趋势,分析论证了剧毒危险化学品定位管理系统的可行性;然后调研了室内定位技术目前的发展现状,论证了RFID技术实现室内定位的优势所在,同时对实现系统的开发工具和技术文档进行了确定;最后提出一种优化改进后的RFID室内定位系统,实现对剧毒危险化学品的追踪定位的管理。 2.搭建二维场景下的RFID室内定位算法LANDMARC和VIRE的仿真模拟实验,从最近邻参考标签数和参考标签密度两个方面对定位精度进行了仿真分析,确定了算法的最优参数后,选择平均误差0.238)的LANDMARC算法进行三维场景的模型搭建。首先结合VIRE算法的模糊地图概念改良三维-LANDMARC算法,改良后定位误差从0.628)减少到0.458),定位精度提高了27.4%;之后考虑到环境因素对定位算法性能的影响,加入卡尔曼滤波算法进行改进,改进后的算法平均定位误差从0.468)减少到0.348),精度提高了26.1%。经过两次改良,定位精度提高了53.5%,稳定性也有较大的提升。 3.通过对实验室实际需求的总结分析,从经济成本和可行性两个角度出发,设计开发了由RFID系统和上机位用户交互平台构成的剧毒危险化学品定位管理系统。首先对系统的硬件做了详细的分析和研究,系统在硬件结构上将实验室根据天线的位置分成四个方位,每个方位设置携带位置信息的参考标签辅助定位,根据仿真模拟情况,对参考标签密度分布和数量进行了相关分析。然后是上机位用户交互平台的实现,该平台利用B/S架构,采用Java最新前后端技术框架进行开发,利用小型关系型数据库My SQL进行数据的存储,实现交互友好的化学品基础信息管理和剧毒化学品定位管理平台。 本文设计的剧毒危险化学品定位管理系统不仅能实现对实验室内的化学品进行基础的信息管理,还能精准的对剧毒危险化学品进行定位管控,极大的提高了实验室内化学品的管理效率。

关键词： RFID   Ultra High Frequency RFID tags   measurement   Carbon Fiber Reinforced Polymers (CFRPs)  

摘要： Data collection during the production process plays a key role in the management and control of goods within the company. In this work, the main focus is on the possibility of embedding radio frequency identification (RFID) technology in carbon-fibre reinforced polymer (CFRP) components to evaluate the readability of commercial Ultra High Frequency system by varying their covers, which is also partly in CFRPS. The samples produced and the tags used derived on previous studies, in which configurations with the tag housed inside were established and studied. Two RFID tags were studied that could withstand the harsh environmental conditions, i.e., high temperatures and pressure. This work was not carried out in an ideal environment to assess the theoretical capabilities of RFID sensors, but to understand and evaluate the readability limits of commercial RFID tags embedded in CFRPs. Therefore, an experimental campaign was undertaken to assess the downstream readability of the curing process of tags in laminated mock-ups. It was observed that the curing process had minimal effect on the readability of the tags. Free-space tests were carried out in proximity of metallic elements to determine the change of the reading distance obtained during the test, keeping the fixed antenna used constant.

关键词： 相位误差   相位差测距   中国剩余定理   加权LM  

摘要： 近年来随着智能化技术的突破性进展,基于位置信息的服务模式成为各行各业的关注热点。由于室内是现代人们的主要活动场所,所以快速准确地获取室内位置信息对于实现万物互联具有重要意义。尽管卫星定位技术在室外环境中已基本成熟,但是室内环境中卫星信号会受到屏蔽,因此定位效果不佳。基于射频识别(Radio Frequency Identification,RFID)的定位技术凭借易部署、非接触、低成本等优点,成为国内外学者研究室内定位的关键技术。当前射频定位的主流方法主要是基于信号的接收信号强度(Received Signal Strength Indicator,RSSI)进行定位,但是RSSI受环境干扰较大导致定位精度较差,因此本文利用射频相位的多频特性,提出一种基于多频相位差测距的室内无源RFID定位方法。分析了相位测量的误差来源并提出了相应的误差抑制方法。在研究相位获取和误差模型的基础上,分析相位测量的影响因素并开展标签的耦合效应实验分析相邻标签的干扰性,分别通过参考标签标定法和Gauss-Kalman滤波方法抑制相位误差的系统因素和噪声因素,减小相位数据的波动性。针对相位的周期模糊问题,研究了基于闭式解的中国剩余定理进行测距,提出了多频载波相位差-距离模型,通过发射不同频率的载波信号,获取不同的相位差信息,并利用中国剩余定理求解距离。仿真实验证明,与传统的中国剩余定理相比,定位精度有所提高。提出了基于加权列文伯格-马夸尔特(Levenberg-Marquardt,LM)的改进型室内定位方法,优化求解目标的位置坐标,保证测距方程组求解定位的收敛性。在实际室内场景进行实验,实验结果表明,本文定位算法的平均误差为0.38m,最大误差为0.5m,可以满足室内定位的需要。本文共有图片39幅,表3个,参考文献80篇。

关键词： Surface acoustic wave sensors   RFID   magnetic field sensor   temperature sensor   temperature compensation   multifunctional sensor  

摘要： Magnetic field measurement including a temperature compensation is essential for a magnetic field sensor. This study investigates a magnetic surface acoustic wave (MSAW) sensor in a reflective delay line configuration with two acoustic propagation paths with and without magnetic field sensitive layer. The delay in path with sensitive layer leads to magnetic field detection and the one without enables temperature measurement and thus compensation for the first path. The developed sensor is based on a ZnO/LiNbO3 Y-cut (X-direction) layered structure as Love wave platform. Love wave as a shear wave being more favorable for magnetic detection. Co-Fe-B is considered as sensitive layer to detect magnetic field changes and is deposited on the top of ZnO, but only on one of the two paths. We combined an original configuration of connected IDTs with a high electromechanical coupling coefficient (K-2) mode to improve the signal amplitude. The achieved sensor exhibits a high temperature and magnetic field sensitivity of -63 ppm/degree celsius and -781 ppm/mT, respectively. The temperature compensation method for magnetic field measurement is demonstrated using a differential measurement by subtracting the delay times obtained for the two paths with and without the sensitive layer. Finally, the sensor exhibited good repeatability at various temperatures. Moreover, the device developed allows in addition to the multisensor functionality, the radio frequency identification (RFID) which is necessary for the deployment of sensor networks.

关键词： RFID   smart manufacturing   six sigma   hybrid DMAIC   harmonic   fuzzy TOPSIS  

摘要： Customers' requirements for product quality are increasing and more and more manufacturing companies are improving the quality of processing conditions at each production process by applying advances in Internet Technologies, Internet of Things, Big Data, Industry 4.0, Industrial Engineering Tools, Multi-objective optimization algorithms, Digital Numerical Control (DNC) method, and Six Sigma tools to improve productivity and quality of product. Continuous improvement of the manufacturing process presents a huge opportunity for the transformation of the normal production model to smart manufacturing. Manufacturing condition data, production data, quality of product data, and power quality data are measured and collected in real-time forming big data fed into operation analysis of the development strategy of the manufacturing company. In this study, the implementation of the Hybrid DMAIC (Define-Measure-Analyze-Improve-Control) method in six sigma is presented in detail based on the statistical hypothesis testing techniques for analyzing production data applied at the measurement phase, Multi-objective decision Fuzzy TOPSIS techniques applied to choose the best improvement solution applied at the analysis phase, Multi-objective optimization technique optimizes production conditions, and the DNC method performs automatically program call by RFID system applied at improvement phase, measurement technique, real-time measurement result collection and analysis by Industry 4.0 system and the method of phase shift is used to keep Total Harmonic Distortion (THD) and Total Demand Distortion (TDD) less than 5% within the international standard limits defined by IEEE 519:2022 and IEC 61000 applied at control phase. A common data system linking all activities at a particular manufacturing process and hybrid DMAIC in Six Sigma continuous improvement model is proposed in this study. This research's results, the rate of occurrence of smaller-than-standard outer diameter defects decr