MSCNN-LSTM Model for Predicting Return Loss of the UHF Antenna in HF-UHF RFID Tag Antenna

High-frequency(HF)and ultrahigh-frequency(UHF)dual-band radio frequency identification(RFID)tags with both near-field and farfield communication can meet different application scenarios.However,it is time-consuming to calculate the return loss of a UHF antenna in a dualband tag antenna using electromagnetic(EM)simulators.To overcome this,the present work proposes a model of a multi-scale convolutional neural network stacked with long and short-term memory(MSCNN-LSTM)for predicting the return loss of UHF antennas instead of EM simulators.In the proposed MSCNN-LSTM,the MSCNN has three branches,which include three convolution layers with different kernel sizes and numbers.Therefore,MSCNN can extract fine-grain localized information of the antenna and overall features.The LSTM can effectively learn the EM characteristics of different structures of the antenna to improve the prediction accuracy of the model.Experimental results show that the mean absolute error(0.0073),mean square error(0.00032),and root mean square error(0.01814)of theMSCNNLSTM are better than those of other prediction methods.In predicting the return loss of 100UHFantennas,compared with the simulation time of 4800 s for High Frequency Structure Simulator(HFSS),MSCNN-LSTM takes only 0.927519 s under the premise of ensuring prediction accuracy,significantly reducing the calculation time,which provides a basis for the rapid design of HF-UHF RFID tag antenna.ThenMSCNN-LSTM is used to determine the dimensions of the UHF antenna quickly.The return loss of the designed dualband RFID tag antenna is−58.76 and−22.63 dB at 13.56 and 915 MHz,respectively,achieving the desired goal.

Concurrent collision probability of RFID tags in underground mine personnel position systems

According to the basic requirements of underground mine personnel position systems and the working characteristics of active RFID tags,we studied the cause of concurrent collision of RFID tags and leak reading probability,by means of theoretical analysis and computation.The result shows that the probability of wireless collision increases linearly with an increase in the number of tags.The probability of collision and leak reading can be reduced by extending the working period of the duty cycle and using a backoff algorithm.In a practical application,a working schedule for available labels has been designed according to the requirement of the project.

Device-Free In-Air Gesture Recognition Based on RFID Tag Array

Due to the function of gestures to convey information,gesture recognition plays a more and more important part in human-computer interaction.Traditional methods to recognize gestures are mostly device-based,which means users need to contact the devices.To overcome the inconvenience of the device-based methods,studies on device-free gesture recognition have been conducted.However,computer vision methods bring privacy issues and light interference problems.Therefore,we turn to wireless technology.In this paper,we propose a device-free in-air gesture recognition method based on radio frequency identification(RFID)tag array.By capturing the signals reflected by gestures,we can extract the gesture features.For dynamic gestures,both temporal and spatial features need to be considered.For static gestures,spatial feature is the key,for which a neural network is adopted to recognize the gestures.Experiments show that the accuracy of dynamic gesture recognition on the test set is 92.17%,while the accuracy of static ones is 91.67%.

Passive RFID Tag for Railway Application

Passive RFID tags based on narrow band absorbers are proposed for railway applications. The tags consist of absorbing tiles of size 30 × 30 cm2. The de-signs of these narrow band absorbers are presented based on infinite array approximation by using periodic boundary conditions. Then, the radar cross sections (RCS) of finite tiles of these designed absorbers are compared with the corresponding RCS of a conduction plate of the same size of the tiles. The difference between the RCS of the absorbing tiles and the conducting tiles corresponds to the RFID digit “1” or “0”. An experiential verification for a sample of these narrow band absorbers is presented based on measuring a fi-nite tile inside a transverse electromagnetic (TEM) cell. The design of this TEM cell is also discussed in detail.

Parallel Response Ternary Query Tree for RFID Tag Anti-Collision

A tag-collision (or missed reads) in RFID system (Radio Frequency Identification) system degrades the identification efficiency. The so-called tag collision is that a reader cannot identify a tag when more than one tags respond to a reader at the same time. There are some major anti-collision protocols on resolving tag collision, e.g., ALOHA-based protocol, binary tree protocol, and Query Tree (QT) protocol. Up to date, most tag anti-collision protocols are QT protocols. QT protocols are categorized into M-ary query tree (QT). In the previous literature, choosing M = 3 (i.e., a ternary QT (TQT)) was proven to have the optimum performance for tag identification. Recently, Yeh et al. used parallel response approach to reduce the number of collisions. In this paper, we combine the partial response and TQT to propose an effective parallel response TQT (PRTQT) protocol. Simulation results reveal that our PRTQT outperforms Yeh et al.’s protocol and TQT protocol.

Recharging RFID Tags for Environmental Monitoring Using UAVs: A Feasibility Analysis

RFID tags are used for different purposes. One of the major problems to be addressed, particularly for monitoring purposes, is their limited power autonomy. Tags must perform different tasks with limited power consumption and their batteries capacities are often too low, even if low power consumption techniques are implemented. In these operational situations tags should be kept in operation for long periods of time and the common solution is to go directly where they are installed and recharge them manually or change their batteries;alternatively, when possible, small photovoltaic (PV) panels may be adopted. This paper proposes a feasibility analysis of how it is possible to recharge a multipurpose RFID tag using a UAV (Unmanned Aerial Vehicle), which is programmed to go above the tags and recharge them. This possibility is analyzed from an energetic point of view assuming to recharge a Wireless Sensor Network (WSN) using a common commercial UAV adequately instrumented using the wireless power transfer technique.

Embedded UHF RFID Tag for Durability Monitoring in Concrete

This paper describes the design of a battery-assisted Ultra-High Frequency (UHF) Radio-Fre- quency IDentification (RFID) tag suitable for embedding in concrete materials and its measurement in a mortar slab. The device is built to communicate wirelessly not only the ID number of the RFID chip but also the digitalized output of a strain gauge sensor. Design optimizations of the RFID antenna is based on published permittivity and conductivity values of concrete. Experimental read ranges are measured from 800 to 1000 MHz with the help of commercial test equipment. Reading is possible up to 50 cm from the surface of a mortar block for a tag embedded 5 cm below the surface. This result is the first published one for RFID tags embedded in concrete or mortar.

基于RFID和磁导航的AGV小车S7-1200PLC控制系统设计

该项目利用S7-1200PLC作为AGV主控制器,采取驱动轮差速进行转向控制,采用磁导航传感器和RFID标签传感器实现循迹和定位功能,实现AGV小车在立体仓库、VMC850数控加工中心、CK40S数控车床、RB20工业机器人、装配单元之间产品的搬运功能。

木托盘RFID标签安装方式有限元分析及试验研究

目的采用仿真和试验手段并用的方法,研究RFID标签在木质平托盘上的适用安装方式及其对使用性能的影响。方法进行Ansys有限元仿真,分析木质平托盘承载和冲击试验中采用螺钉紧固及黏结剂粘贴方式安装的RFID标签所受应力。作为对比,在实验室进行实物试验,测量RFID标签表面应力,并测试标签读写性能。结果在托盘承载和冲击试验中,从RFID标签各构件及标签连接件的受力分析看,2种安装方式下的RFID标签均未出现脱落和物理性损坏。冲击试验后的RFID标签能够通过读写功能测试。有限元仿真与实物试验的应力分析结果相互吻合,验证了结果的正确性。结论RFID标签采用螺钉紧固和黏结剂粘贴的安装方式都能满足使用要求,且螺钉连接的耐用性更好。研究结果为RFID标签在木质平托盘的安装方式选择提供了理论依据。

基于RFID的智能分类编目系统设计与实现

阐述基于RFID技术的智能分类编目系统设计,它可有效提升图书馆对图书进行分类编目的效率、降低管理成本。RFID技术的应用,有效避免人为原因造成的分类错误。

用于水电机组螺栓松动检测的无源RFID标签天线模型优化

为辅助螺栓松动检测管理,应用射频识别技术(radio frequency identification,RFID),设计了用于螺栓松动检测的无源RFID标签天线模型。首先,采用弯折偶极子和末端短路设计,使天线达到目标中心谐振频率;其次,在标签天线结构下方增加类似于匹配环结构的矩形环馈设计,使标签天线与目标芯片实现阻抗匹配。通过高频结构仿真(high frequency structural simulator,HFSS)软件对标签天线结构参数进行仿真优化,确定标签天线的最终尺寸为60.0 mm×60.0 mm×1.6 mm。Farsens Rocky100芯片在915 MHz时的阻抗为51-j460Ω,仿真结果表明标签天线的阻抗为46.7+j461.4Ω,与芯片匹配良好;标签天线的中心频率为915 MHz,得到的回波损耗小于-10 dB带宽的范围为840~970 MHz,增益最大为0.8 dB,能满足螺栓松动检测的距离要求。该研究在螺栓松动检测方面具有一定的应用价值。

基于RFID电力标签的电力工器具抗电磁干扰性能研究

射频识别(Radio Frequency Identification,RFID)技术是一种利用无线电波进行识别和跟踪的技术,被广泛应用于各种物品和设备的标签中,以实现自动化管理和信息追踪。深入探讨了提高RFID电力标签抗电磁干扰性能的设计方法,包括合理选择材料、优化天线设计及采用先进的信号调制技术等策略。这些技术措施能够显著提升RFID标签在电力工器具应用中的稳定性和可靠性,从而适应复杂的电磁环境并保证电力系统的高效运行。

基于分组查询树的RFID标签识别算法

为了解决多标签碰撞问题,设计一种新型RFID防碰撞算法。通过在QT防碰撞算法基础研究,针对大量移动标签场景提出了一种分组查询树防碰撞(GQT)算法。新算法通过将标签ID码进行分组的方式进行重新编码,按连续三比特位一组形式进行组合,同组之间前两位做异或或者同或运算,如果异或结果得到的是第三位的值,将这组编号为0,如果同或运算结果为第三位的值,将这组编号为1,交叉进行编号,将生成的编号进行重新编码形成新的二进制比特位,最后采用查询树算法进行识别。理论分析表明GQT算法能消除空闲时隙,仿真结果表明,与QT算法和AHT算法作比较,GQT算法能减少碰撞时隙数,并且在大量标签数的情况下,算法识别效率能保持在0.76左右。可见GQT算法在物流运输、贮存、管理等场景具有良好的应用价值。

基于RISC-V的UHF RFID标签数字基带设计

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来对目标对象进行识别,并由此获取目标对象的相关参数的技术。随着UHF RFID技术被应用于越来越多的领域,为了能够更加快速地适应各种应用需求,论文将UHF RFID标签数字基带以SOC的形式实现。在整个数字基带设计中,标签的物理链路层通过硬件实现,包括FM0/Miller编码模块,PIE解码模块、CRC编码/校验模块等。同时,标签识别层通过使用开源RISC-V内核蜂鸟E203和部分硬件设计共同完成。经过验证,论文设计能够在FPGA上成功运行并符合ISO/IEC_18000-6C协议[1]中规定的通信流程。

基于有界成分分析的欠定RFID标签防碰撞技术

针对无线射频识别(Radio Frequency Identification,RFID)面临的标签碰撞问题,即同频干扰消除,从通信输层信号处理的角度,将多标签防碰撞问题建模为盲源分离(Blind Source Separation,BSS)问题。为降低阅读器天线成本,利用标签通信信号的有界性,提出了一种欠定的基于有界成分分析(Bounded Component Analysis,BCA)的RFID标签防碰撞技术,将欠定的标签信号碰撞模型与BCA机制相结合。经仿真试验结果表明,所提BCA算法能更好地解决欠定碰撞问题,改善标签信号同频干扰消除的效果,提高系统误码率(Bit Error Rate,BER)性能,降低欠定模型系统的复杂度。

丝网印刷ETFE杂原子掺杂制备导电碳RFID标签

通过自制的ETFE膜与杂原子掺杂导电碳的丝网印刷技术,制备了RFID电子标签,采用红外光谱、扫描电子显微镜、X射线衍射、差示扫描量热等手段进行了表征测试。结果表明,ETFE膜表现出优异的机械性能,再加上杂原子掺杂导电碳的优异导电性,所制备的RFID电子标签的拉伸强度达到33.9MPa,断裂伸长率为486.2%,撕裂强度为69.5N·mm^(-1),方块电阻达到65Ω。

基于顶部标签的RFID室内定位优化算法研究

RFID室内定位技术有信号穿透性强,成本低廉等诸多优点,但其识别距离有限且定位精度不佳。提出一种采用顶部标签布置的RFID识别方法和双重指纹匹配的搜索算法,并进行了相应的实验验证,实验过程表明利用RFID识别范围形成的区域将实验空间进行划分提高了K近邻系列算法的匹配精度。文中采用KNN(K-Nearest Neighbor)、WKNN(Weight KNearest Neighbor)和BWKNN(Bayes Weight K-Nearest Neighbor)三种不同的算法分析了相同RFID目标的定位性能。实验结果显示,BWKNN算法能够有效的提升RFID指纹算法定位精度:BWKNN算法的平均定位精度为31.24mm,相较于KNN算法提升64.55%;相较于WKNN算法提升50.03%。

基于RFID温度标签的变电站装配式线缆槽盒温度监控方法

由于红外测温仪和温度传感器在采集温度数据时会出现偏差,且监控方法能耗较高。对此,提出基于RFID温度标签的变电站装配式线缆槽盒温度监控方法。设计一种RFID温度标签,采集变电站装配式线缆槽盒温度数据,并实施数据清理以及数据变换预处理。结合关联维提取预处理好的温度数据特征。通过计算异常指数,判断变电站装配式线缆槽盒温度异常状态。结果表明:与基于红外测温仪的监控方法和基于温度传感器的监控方法相比,所研究的方法采集数据与真实数据的拟合度更高,达到0.9852,说明采集数据更为准确,该方法更能维持长时间的监控工作。

基于YOLOv5的RFID电子标签检测研究

在无线射频识别(RFID)电子标签的生产过程中,由于制造技术的不完善、操作失误和设备问题,生产的RFID电子标签常随机出现包括墨点、胶带、空贴等多种缺陷。为了帮助工厂降本增效,加快工厂自动化生产线智能化升级,使用深度学习算法YOLOv5,结合视觉检测设备在生产线上自动检测RFID电子标签的缺陷。研究提出的RFID电子标签检测方法的测试结果显示,YOLOv5模型在缺陷检测上的准确率高达98.9%。将模型部署到生产线上,该模型展示了全覆盖、高速度和高精确度的检测性能,大大提高了RFID电子标签的检测效率。

RFID在金属物料复杂表面状态下的稳定性研究

射频识别(RFID)技术利用电磁波实现无接触的自动识别。在实际应用中,射频识别技术的应用场景复杂多变,因此,通过仿真实验及真实环境测试,对RFID技术在金属物料复杂的表面状态下的稳定性进行研究。结果表明,在表面不规则的异形金属背景下会使RFID标签的读取稳定性下降;不同金属材质、不同金属形状以及金属表面具有薄涂层等因素都不会影响RFID标签的读取稳定性。