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关键词： Authentication   ciphers   cryptography   encryption   field programmable gate array   nearfield communication   performance analysis   radio frequency identification   simulation  

摘要： Near Field Communication (NFC) has emerged as a pivotal wireless technology for short-range data exchange between devices, including smartphones and wearables. Leveraging Radio Frequency (RF) signals and robust authentication, NFC ensures secure communication in proximity. Mutual authentication (MA) holds paramount importance for establishing trust between device pairs. A prime example of NFC technology is Radio Frequency Identification (RFID), wherein seamless communication occurs between a reader and a tag. However, security and privacy concerns are critical factors in RFID systems, necessitating effective authentication protocols. This paper introduces an efficient and secure MA mechanism for RFID devices, using lightweight block ciphers (LBCs). Specifically, the extended tiny encryption algorithm (XTEA) and the hummingbird algorithm (HBA) using the cipher block chaining (CBC) mode is designed. These tailored algorithms establish a secure communication channel between RFID tags and readers. Notably, the proposed RFID-MA using XTEA and HBA occupies less than 2% of the chip area, encompassing slices and lookup tables (LUTs), and achieves authentication with execution times of 11.6 mu s and 1.34 mu s, respectively. In comparison to the RFID-MA approach employing the XTEA methodology, the proposed algorithm reduces the chip area overhead by 24.6%, total power consumption by 3.5%, and execution time by 88.36%. The proposed algorithm is implemented using Verilog hardware description language (HDL) within the Xilinx environment and is realized on a Artix-7 field programmable gate array (FPGA) platform, utilizing the ModelSim simulator. The proposed research extensively presents simulation and synthesis results while considering the critical hardware constraints such as time, power, and area. Furthermore, this study has also conducted a comprehensive performance analysis, comparing essential metrics with existing LBC and authentication methodologies, showcasing substanti

关键词： UHF RFID   polarization mismatch   SLAM   extended Kalman filter  

摘要： Several localization algorithms exploit the dependence of the phase shift of the backscattered RFID signal on the tag to the reader distance. However, in some configuration setups, the phase shift also depends on the relative orientation between the tag's and the reader's antenna. In this paper we investigate the effects of this dependence on the Simultaneous Localization and Mapping (SLAM) problem, by comparing the approach where this dependence is included in the measurement model with the approach where it is rather compensated through a time varying phase offset subject to estimation. Simulation and experimental results show that the algorithm which includes this dependence in the measurement model provides better performances with respect to the other approach. Some indications and numerical results are also reported in the paper to evaluate if this dependence may be beneficial in solving the SLAM problem.

关键词： RFID system   coupled tags   read-range   T-match   statistical analysis  

摘要： The aim of this paper is to propose a statistical analysis of the performance of an RFID system in a high-density context, based on a physical model which takes into account the mutual coupling and random position of tags. The read-range of an isolated tag is measured and validated from simulation. The degradation in terms of read-range and the power absorbed by the RFID chip is analysed in the presence of surrounded short-circuited tags. Then a set of randomly distributed RFID tags are modelled by a set of loaded half-wave dipoles distributed over an electrically small area to observe the absorbed power on circuit-level. An impedance matching technique employing a T-match has been adapted with dipoles for maximum power transfer in the forward link. The coupling effects taking into account the randomness of dipoles are studied using linear and circular polarisations of the incident field. Numerical Electromagnetics Code (NEC) simulator and High-Frequency Structure Simulator (HFSS) are used for the assessment of forward links for dipoles (with and without T-match) and tags respectively.

关键词： Integrated circuits   Batteries   Sensitivity   Radio frequency   Temperature sensors   Radiofrequency identification   Medical services   Radio frequency identification   battery-assisted sensor tag   energy harvesting   Internet of Things  

摘要： This paper presents a comprehensive overview and analysis of the state-of-the-art (SoA) in semi-passive or Battery-Assisted (BAP) Ultra-High Frequency (UHF) Radio Frequency Identification (RFID) sensor tags compliant with EPC Global G2/ISO-18000C. These tags operate on the same communication principle as fully passive sensor tags but incorporate a battery or an energy harvesting module. This additional power source extends communication ranges and enables power demanding applications using low-power microcontrollers (MCUs) and higher-end sensors. This article also analyzes various key features, including tag integrated circuit (IC) architecture, types of energy harvesting modules, and communication range. The main conclusions are threefold. Firstly, selecting the appropriate tag IC requires a careful analysis of its features such as sensitivity, sensor interfaces, or data logging capabilities. For instance, among the solutions examined in the SoA, half of them opted for a tag IC capable of MCU communication via SPI or I2C buses. Secondly, it is essential to assess both the forward and backward communication links to leverage the sensitivity of the tag IC in BAP mode. Interestingly, only one-third of the SoA solutions achieved the theoretical communication range anticipated by the sensitivity of the tag IC. Finally, an energy budget analysis is required to ensure that the energy generation suffices to meet the energy requirements of the tag. While most solutions rely on batteries as the energy source and analyze battery lifespan, only a few studies employing energy harvesters conduct an energy budget analysis due to the additional complexity involved.

关键词： Radio frequency identification (RFID)   flexible   strain sensor   reconfigurable antenna  

摘要： Technical method for strain detection using radio frequency identification (RFID) technology is characterized by flexibility, low cost and high intelligence. The traditional planar-based rigid sensing antennas are basically made of rigid substrates, which have the disadvantages of poor surface fit and flexibility, so flexible electronics are gradually applied in the field of structural health monitoring (SHM) to solve the challenge of non-planar deformation monitoring. In this paper, we propose a flexible reconfigurable strain-gauge RFID sensor with an encoding capability of 4 bits. The encoding structure is based on a coupled U-shaped resonator with strain resonance in the UHF RFID frequency band from 0-4 GHz. Reconfigurability is achieved by introducing a diode with modulated bandstop filtering in the resonator. The proposed antenna uses an FPCB board with total dimensions of 100 mm chi 71.4 mm chi 0.508 mm. It is subjected to thermal stability experiments, four-point bending strain and strain monitoring inside concrete, and the simulation and measurement results verify the feasibility of the design. This is important for realizing high-performance integrated strain monitoring in structural health monitoring using RFID technology.

关键词： 装配式建筑物联网   UHF RFID   天线   溯源   传感  

摘要： 近年来,在装配式建筑物联网（Prefabricated Construction Internet of Thing,PC-IOT）中,UHF RFID已被证明是预制构件（Prefabricated Construction,PC）的资产管理和内部物理感知极具潜力的硬件技术。然而,建筑环境中复杂的电磁干扰极大限制了UHF RFID作为标签溯源和无线传感技术的应用,例如金属和混凝土等。此外,抗干扰和功耗问题也是PC-IOT中PC无线感知的关键问题。因此,需要进一步探索能够抵抗建筑环境干扰的RFID标签技术和低功耗无线传感技术。本文通过引入电阻抗超表面技术和自匹配耦合馈电网络技术设计了抗金属的高性能UHF RFID标签天线,通过引入耦合馈电圆弧提高增益技术和PVC引脚降低混凝土影响的设计,显著提高了UHF RFID标签的增益并成功提高了标签读取率。更进一步地,提出了基于本文标签天线设计的低功耗无线无源感知技术方案。对设计的标签进行了电磁学和电路性能研究,验证并分析了标签的工作原理。本文的具体研究工作如下:1、设计制备了一种高性能的抗金属自匹配网络全波偶极子天线。采用的金属圆环电感耦合馈电结构,在UHF频段内,使全波偶极子的高感性阻抗和RFID IC大容性阻抗实现了很好的匹配。采用电阻抗超表面以补偿寄生电容,减小天线与金属平面的强相互作用,降低了金属背面对天线的影响。该天线安装在金属上的实测带宽(|S11|≤-10 d B)达到632 MHz（69%）和最大读取距离为20.19 m。嵌入混凝土时,最大读取距离仍达到4.63 m。2、本文设计实现了一种应用于预制构件溯源的低成本、嵌入式、抗腐蚀、抗干扰的预制构件RFID溯源标签。首先,根据耦合馈电结构的原理,本文通过增加耦合馈电圆弧提高耦合效率,将峰值增益从2.65 d Bi提高到2.96 d Bi;其次,通过引入成本较低、易操作、工艺成熟的PVC材料作为封装基底,实现封装以防止混凝土环境的腐蚀;然后,通过引入一种PVC支脚的设计降低混凝土环境的电磁干扰,为标签提供了嵌入预制构件的功能,进一步仿真设计并讨论了支脚和混凝土对标签增益的影响;最后,为了在印证性能,进行了相关电磁仿真研究和实地测试验证了支脚对标签读取率的提高。最终,基于本文的标签设计,提出了一种应用于PC溯源感知的技术方案。

关键词： 智能制造   深度强化学习   离散生产   RFID系统   动态感知决策  

摘要： 中小离散型制造企业作为中国制造业的重要组成部分,迫切的希望进行智能制造转型,为了实现此类企业初步转型智能化的目标,本文提出通过选择智能制造(Smart Manufacturing,SM)感知层关键使能技术应用于企业离散生产线中进行在制品(work in process,WIP)质量控制以实现产线动态感知的理论,并通过构建评估模型和感知决策模型,以理论结合模型的方式得到了有效的感知技术应用方法。首先,本文介绍分析了国内外各种智能制造思想和理论体系架构,综合对比得出了这些理论之间的基层共性概念和支撑技术,并对中小离散型企业的转型要点进行分析总结,确定出了首先实现生产线初步智能化的设想,从而确定了本文的研究内容以及研究方案。然后,通过总结分析射频识别(Radio Frequency Identification,RFID)技术感知采集WIP质量信息的原理流程,得到实现产线动态感知的关键决策因素。对感知决策因素进行数学分析与建模,利用决策因素性能指标分析产线运行过程中不同决策因素对生产线质量数据采集的影响,并基于马尔科夫链(Markov Chain,MC)构建了产线动态感知决策因素性能评估模型,该模型为决策模型提供数据支撑。其次,基于深度强化学习(Deep Reinforcement Learning,DRL)理论建立RFID系统感知决策模型,搭建模型四元组结构构成决策模型的输入,输出为系统感知策略,以总成本最小化为模型约束条件,搭建了完整的感知决策模型。并利用DRL中经典算法DQN(Deep Q Network)对决策模型进行求解,为实例验证部分打下完整的理论与模型基础。最后,利用数值实验的方式搭建实验环境,利用DQN算法对决策模型进行完整的求解,获得了有效的生产线RFID系统应用策略。提高了生产线质量数据采集能力,并极大降低了导入成本。有效地帮助企业甄选出与生产内容高匹配度的RFID硬件及合理有效的硬件安装位置。

摘要： 多年来，芬兰Ahonkyl?的居民以及经过该村大道的通勤者，几乎没有本地购物的选择。Petri Jaakola考虑到当地居民对便利购物的需求，最终推出了一个基于无线射频识别(RFID)技术的商店，名为Mini Smart Ahonkyl?。这家商店全天24小时营业，大部分是自动化的。Mini Smart Ahonkyl?于2022年开业，服务于该地区不断增长的人口，提供大约800种食品和饮料的自动供应，包括牛奶、面包、咖啡和苏打水。

关键词： RFID技术   惯性定位   行人航迹推算   舱室定位   地图匹配  

摘要： 我国是一个海洋大国,越来越多的人们投身于海上作业,对船舶人员的管理提出了更高的要求。本文结合船舶人员动态化管理系统较为稀缺的现状,以江海作业为背景,基于RFID和惯性技术设计了一个船舶人员舱室定位系统,为船舶人员管理的信息化提供了一个新的方案。主要研究内容如下:(1)针对实际测距时RSSI值波动且存在异常值、对数-正态分布测距模型中损耗因子和路径损耗在船舶环境下取值不明确、RFID定位常用方法锚节点利用率低且不考虑距离对定位结果影响的问题,提出以下解决方法:根据高斯函数特性确定RSSI值的分布进行数据过滤;用线性回归的方法建立RSSI值与和的方程组以得到其最佳取值;用一种分组加权质心定位法以充分利用锚节点并减轻距离对定位结果的影响。针对传统PDR算法步态检测存在的加速度检测波动大且存在伪步态、步长估计模型变量少、方向估计磁偏角跳跃幅度大且误差累积明显的问题,提出以下解决方法:用滑动窗口平均预处理数据结合多阈值约束进行步态检测;在步长模型中加身高、步频、波峰/波谷加速度变量并计算其线性参数;用关系系数推算陀螺仪测量的转动角度和IMU与地磁北的夹角之间的关系并建立模型。(2)针对RFID定位波动较大和惯性定位误差随时间发散的问题,设计卡尔曼滤波,建立状态方程和观测方程进行融合定位。为了使上位机显示的轨迹更加准确,提出一种融合定位结合地图匹配的方法,建立监控区域的地图模型,用一种标志点检测的方法对人员的位置和方向进行修正。(3)在理论和算法研究的基础上完成硬件设计。根据系统要求确定功能和设计原则,制定总体方案。对关键元器件进行选型,对主控、最小系统、外围、射频芯片、IMU、通讯等电路进行设计,最后给出系统组合完毕后的实物图。(4)对组装完成后的系统进行实测。选择场地并布置硬件,设计实验对系统性能进行测试,分别是RFID/惯性融合定位和单惯性定位、结合地图匹配和不结合地图匹配对比实验。实验人员按规定好的路线行走,用不同的定位算法进行检测,对上位机显示的人员轨迹进行分析,实验结果表明本系统能够提供更为精确和稳定的人员定位,具有实际使用意义。