Radio Frequency Technology for Automated Manufacturing and Logistics Control. Part 1: Passive RFID Systems and the Effects of Antenna Parameters on Operational Distance

Identification plays an important role in automation. In the near future radio frequency identification (RFID) will be an option for mass production automation projects. RFID represents a contactless method for data transfer in object identification. Generally, RFID systems consists of three components: 1. A small electronic data carrying device called a transponder, or a tag that is attached to the item to be identified. 2. A reader or a scanner that communicates with the tag by using radio frequency signals. 3. A host data processing system that contains information on the identified item and distributes information to other remote data processing systems. An RFID system can be considered as a wireless communication system because the scanner communicates with the tag by using electromagnetic waves at radio frequencies. The performance of this communication link can be studied by determining the read range for backscatter RFID systems. The read range, or the distance at which the reader unit notices the tag, depends on many factors. Several parameters, e.g. the frequency used for identification, the gain, the orientation and the polarisation of the reader antenna and the transponder antenna, and the placement of the tag on the object to be identified, will all have an impact on the RFID system read range. In this paper, Part 1, we focus on presenting an overview of different passive RFID systems and the read range of the backscatter RFID system. The function of frequency, antenna gain and polarisation mismatch are analysed and discussed. In Part 2, several manufacturing automation cases of different natures will be presented. These cases contain a selection of requirements for an RFID system and they are analysed using the information presented in this paper.     

Radio frequency technology for automated manufacturing and logistics control. Part 2: RFID antenna utilisation in industrial applications

The trend in industrial automation is to move towards fast and real-time identification, further improving the high-level of accuracy that is needed to enable continuous identification and monitoring. The interest in adopting radio frequency identification (RFID) technology for use in automation systems with minimal manual involvement is increasing rapidly. RFID systems are capable of providing real-time object visibility with high accuracy enabling continuous identification and location of all items and thereby providing accurate real-time data management instead of simple snapshots. In this paper, the use of multiple reader antennas is examined against collision and interference avoidance. Also, antenna operation is studied in typical industrial environments containing metallic objects or other conducting surfaces. In addition, this paper reviews different tag antennas and their characteristics for particular item identification cases. These cases include items made of specific materials that obstruct or prevent radio wave propagation by either absorbing or reflecting them. The results given in this paper are fully applicable with practical RFID solutions.     

Inkjet-printed passive UHF RFID tags: review and performance evaluation

In this paper, the performance and the feasibility of inkjet-printed dipole RFID tag antennas are experimentally studied in the implementation of identifying objects with different electromagnetic properties. To estimate the performance quality, we compare our results to those obtained using traditional etched copper dipole tag antennas. We first examine the performance characteristics, i.e. the read range and the radiation patterns, of tags in free space. Then we attach the tags directly to target objects and compare the optimum performance on target objects to that of the tag in free space. The obtained results provide information about the behaviour of inkjet-printed tag antennas on different objects. This information can be used to optimize the inkjet-printed tag antenna performance for use on objects with different characteristics.     

Characterization of UHF RFID tags fabricated directly on convex surfaces by pad printing

The possibility of pad printing in RFID tag antenna manufacturing is investigated. Passive UHF RFID tags were printed on flat and on convex surfaces with two different polymer thick-film silver inks. The effect of the ink and substrate material properties on tag antenna performance was examined. The goal was to provide information which is needed in adapting the pad-printing technique in RFID tag manufacture. The results show that pad printing is suitable for tag manufacturing on flat and on convex surfaces. The curvature of the substrate did not significantly affect the tag performance. It was more important to take into consideration other substrate properties, ink characteristics, morphology, and printing parameters. The best practice is to take these matters into consideration in the initial tag design process to ensure proper tag performance at the desired frequency.     

基于场景几何特征的ETC识别范围预测方法

超高频(UHF)射频识别(RFID)系统具有标签成本低、识别距离远等优点,在电子不停车收费(ETC)等智能交通领域具有应用潜力。受电波的随机多径传播制约,实际应用中难以准确估计标签识别范围。针对ETC应用场景具有几何共性的特点,基于电波传播的几何光学方法,通过对标签接收多径射线的构成进行分析,融入场景几何特征和天线射频特征参数,提出了一种标签识别范围的预测方法。实际场景测试与仿真表明,能较精确预测标签在三维空间中的接收功率分布和识别范围,且精确性高于对数正态等经验模型,而复杂性低于电磁场的商用仿真软件。     

一种激光全息RFID双重防伪电子标签设计

介绍了一种激光全息射频识别(RFID)双重防伪电子标签的设计方法,并通过理论分析和电磁仿真,研究了激光全息膜对无源RFID天线射频性能的影响规律。在此基础上设计了一款共面倒F天线,并应用于无源RFID标签,且制作了样品。测试结果表明,使用该天线的激光全息RFID标签能达到较好的读取效果,并且受激光全息膜的影响较小。     

射频识别标签天线的按需微喷射制备

基于数字化微喷射技术搭建了射频识别(RFID)标签天线的按需微喷射制备系统。首先,将纳米银导电墨水按需微喷射到镀有疏水化薄膜的聚对苯二甲酸乙二醇脂(PET)基底表面形成天线图形;然后在恒温干燥箱内烧结,形成RFID标签天线。实验研究了微喷射系统参量对液滴产生的影响以及制备参数对纳米银导线成线的影响,制得了最小线宽为100μm、厚度为2.8μm、电阻率为5.2μΩ·cm且阻值具有较好线性度的导线。设计、仿真和制备了弯折偶极子天线,并对其性能参数进行了测试,结果显示其天线谐振频率、带宽和谐振点S11参数等与仿真结果具有较好的一致性。实验结果表明,按需微喷射导电银墨水制备RFID标签天线的方法具有系统结构简单、成本较低、液滴微喷射精确、便于制备任意天线图形等特点;制备的弯折偶极子天线尺寸可控、导电性高、阻值均一性好,并具有较好的天线性能。     

Product–service systems in health care: case study of a drug–device combination

A radio-frequency identification (RFID) system has been considered as one of the most promising systems for information technology (IT) asset management because of its well-developed level of technology, worldwide standards and its lower price than other wireless protocols such as WiFi, WiMAX, and Bluetooth. However, RFID systems for IT asset management in business-to-business (B2B) environments are still limited by several constraints such as readable range, sensor capability, and battery problems inherent in existing RFID technologies. In particular, only few research works deal with asset management in a real office environment. This paper proposes a new way of managing IT assets using surface acoustic wave (SAW)-based RFID technology to solve these problems. To show its effectiveness and feasibility, the proposed approach analyzes RFID tag performance based on an electromagnetic test and measures the readability of SAW-based RFID in an office environment. Experimental results show that one of the most hopeful candidates for managing B2B IT assets is the SAW-based RFID system because of its batteryless passive RFID characteristic, relatively long readable range, its potential and inherent sensor capability, and its expandability compared to other RFID systems. Furthermore, the proposed approach systematically analyzes where to attach RFID tags on IT asset devices considering electromagnetic performance based on ID- and sensor-detecting capabilities, which suggests the most appropriate tag position on the device.     

纸基RFID标签天线喷射打印化学反应沉积成形

针对目前射频识别(RFID)标签天线制备成本高、工艺复杂等问题,提出微滴按需喷射3D打印与化学沉积技术相结合制备半波偶极子天线的方法。利用构建的气动式双喷头微滴喷射系统,采用试验研究的方法,对系统按需喷射条件下产生硝酸银与抗坏血酸微滴的一致性以及基板运行速度对成线均匀性的影响进行研究,并对成形导线的电阻率进行测试;在此基础上设计、仿真和制备了半波偶极子天线,对其性能参数进行了测试。结果表明:系统产生的微滴均匀性较好;基板速度小于或等于0.5mm/s时,硝酸银成线边缘光滑度较好;成形导线的电导率为1.57×10~(-5)Ω·m;打印成形的半波偶极子天线谐振频率、谐振点回波损耗S_(11)参数等与仿真结果具有较好的一致性。为RFID标签天线提供了一种低成本制备方法。     

国内外港口集装箱智能标签技术的发展和现状

射频识别（RFID）是一项新的识别技术,其传输数据率高、通信距离长和可靠性高等优点使之超越条形码和IC卡成为下一代识别技术.集装箱货运是目前国际物流行业最主要的形式,利用RFID技术对其进行电子化的管理是一个新兴的课题,本文结合上海港务集团的内贸集装箱智能标签示范线,介绍智能标签在集装箱物流应用中的关键技术和应用前景.     

A performance evaluation method for EMI sheet of metal mountable HF RFID tag

This paper proposes a performance evaluation method for Electromagnetic Interference (EMI) sheet of metal mountable RF identification (RFID) tag. The method is based on impedance matching principle, featuring several advantages such as non-contact, high sensitivity and simple configuration. A wireless power transfer model was used to analyze the measurement result, which was later on validated by numerical optimization method. In order to further characterize the performance of the metal tag in terms of the reading range, the relationship between the power transmission coefficient and the reading range is explored. By using the method, an EMI sheet prototype with precise resonant frequency was fabricated, demonstrating a greater read range over the commercial one.     

EM4905芯片在射频信息解读设备中的应用

射频识别技术是无线电技术在自动识别领域中的具体运用;通过射频信号自动识别目标对象,并获取相关数据。随着天线技术及计算机技术的发展,RFID系统的体积、功耗越来越小,成本越来越低,功能日趋灵活,操作快捷方便可广泛应用于物联网中。EM4905芯片是RFID领域性价比较高的核心器件。文章主要介绍EM4905芯片的工作原理及其在低频射频信息解读设备中的应用。     

射频电子标签天线设计及印刷工艺分析

阐述了基于13．56MHz射频印刷标签天线具体的设计方法和制造工艺。以ICODE芯片为例,描述了整个标签天线结构设计方法,设计并印刷出天线。通过对印刷天线的分析,进而得出印刷天线电感及电容的获得主要取决于设计结构的结论,而对印刷工艺而言,印刷工艺的优化目标之一则是获得较低的天线阻值,从而得到较高的天线品质因子Q,获得理想的天线综合性能,满足感应距离的需要。     

无线传感技术在食品安全运输中的运用

综述了当前无线传感通信技术在食品安全和运输中的发展状况,重点介绍了无线传感网络和无线射频识别不同系统的最新进展和应用,包括基于ZigBee的无线传感网络和被动式、半被动式和主动式的射频识别技术,讨论了无线通信在食品工业的发展趋势,这些技术在环境监控、低温运输控制或追踪等领域,有着广阔的应用前景。     

Warehouse management with lean and RFID application: a case study

This research presents the integration of lean production and radiofrequency identification (RFID) technology to improve the efficiency and effectiveness of warehouse management. More than ten million parts belonging to around 10,000 types in a distribution center were involved in this study. There are more than 10,000 storage and retrieval operations for hundreds of part types on a daily basis. Value stream mapping was used to draw current state mapping and future state mapping (with lean management and RFID) with material flow, information flow, and time flow. Preliminary experiments showed that the average reading rate of electric forklift and hydraulic cart are 99.3 and 99.1 % by fixed ultra-high frequency RFID readers with antenna installed at the receiving/shipping dock and passive tags mounted on box/pallet. The processing time of data transmitting to warehouse management system at receiving and shipping docks was reduced by 99 and 89 %, respectively. The total operation time from current stage to future stage with only lean can be saved by 79 %. With further integration of RFID to lean, the total operation time can be saved by 87 %. Moreover, performance on saving total operation time can be enhanced to 91 % with cross-docking. The benefit of using RFID in the warehouse management is realized and promoted.     

RFID-enabled tracking in flexible assembly line

Radio frequency identification (RFID) technology provides a wireless means to detect and identify objects. By using RFID reader as detecting sensor, an RFID-assisted object tracking system is developed to track the object movement for a flexible manufacturing assembly line. Both range-based and range-free cooperative object tracking algorithms are analyzed for the system. And to achieve tradeoff between the reader plate’s density and cost, only simple readers with omnidirectional aerial are considered in this article. To further enhance the assembly line efficiency, a particle filter model is developed to further process the object tracking results to improve the tracking accuracy. The proposed tracking system can also forecast the movement state of objects in the assembly lines.     

用于移动通信中的新型微机械贴片天线

近年来无线通信在全球范围内得到了迅猛的发展,对收发无线信号的天线尺寸的小型化和性能要求也在日益增加.微带贴片天线以其卓越的性能,得到了广泛应用.传统的半波天线尺寸较大,在小型通信设备中使用会出现许多问题.本文提出了一种在高介电常数上用微机械工艺制作的短接层叠式贴片天线,该天线在硅片和接地板间夹一层Tef-lon(聚四氟乙烯),这样天线的性能得到了提升,相对带宽增加到8.6%,而几何尺寸仅为波长的1/8.天线的测试方向图表明,天线靠近手机电路板时,大部分的电磁辐射会远离使用者的头部,且波束宽度可保证足够大的覆盖范围.此天线是在硅片上进行微机械加工的,可与硅和GaAs集成电路集成在一起,而不会影响电路本身.此天线可适用于移动通信设备.     

机械制造业在制品及其制造资源的自动识别技术研究综述

如何实时准确地获取车间制造资源和在制品的信息,是提高企业的信息化水平和敏捷制造能力的关键。综合国内外的研究现状,机械制造业在制品自动识别最好的办法是利用射频识别技术进行全线跟踪,主要需要解决射频识别设备和管理系统之间的接口问题;制造资源自动识别最好的办法是利用直接标刻技术和数据矩阵码技术,其中需要解决不同的制造资源如何编码、解码以及在恶劣环境下解码算法改进等问题。     

[数据建模]智能车间RFID标签有效识别及制造信息自动关联

提出了一种基于电子产品编码（EPC）和自动身份识别（Auto-ID）的智能车间RFID标签有效识别方法。通过对智能车间中制造资源种类的详细划分,在EPC Global编码规范的基础上进一步细分类型和序列号两个自定义字段,得到了车间内部制造资源的RFID编码结构;根据在制品（WIP）的设计信息和生产数据形成工件制造逻辑,进而利用数据库技术实现制造资源信息在群属、空间、时间上的自动关联;最后对WIP的RFID标签和制造信息的自动关联进行了实验,以验证所提出的模型和方法的可行性及普遍性。     

基于RFID的药品管理系统

为了实现药品的防伪和追踪,基于射频识别(RFID)技术开发了一个药品管理系统。利用UHF900MLow Level Operation类封装了900 MHz读写器,方便地进行900 MHz读写器打开或关闭、寻卡、读卡、写卡等操作。基于Qt进行药品管理系统中标签初始化、药品流通各个环节信息记录的界面设计,并通过信号/槽这种异步方式进行读写器事件的处理,实现有效的药品管理和追溯。