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.

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.

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.

养殖RFID测温定位电子耳标研究——基于智慧农业区块链

首先,介绍了区块链和物联网技术在智慧农业应用的概念;然后,基于结构、温度传感器、RSSI定位和天线等多个模块实现了对测温定位电子耳标的设计;最后,为了验证该RFID测温定位电子耳标的性能,设计了一套放养羊群的养殖信息监测系统,对每只羊的实际位置和体温进行监测。测试结果表明:系统可以准确测量山羊的体温和位置,响应快,稳定性高,符合设计需求。

Design of a passive UHF RFID tag for the ISO18000-6C protocol

This paper presents a new fully integrated wide-range UHF passive RFID tag chip design that is compatible with the ISO18000-6C protocol. In order to reduce the die area, an ultra-low power CMOS voltage regulator without resistors and an area-efficient amplitude shift keying demodulator with a novel adaptive average generator are both adopted. A low power clock generator is designed to guarantee the accuracy of the clock under 4-4%. As the clock gating technology is employed to reduce the power consumption of the baseband processor, the total power consumption of the tag is about 14μW with a sensitivity of -9.5 dBm. The detection distance can reach about 5 m under 4 W effective isotropic radiated power. The whole tag is fabricated in TSMC 0.18μm CMOS technology and the chip size is 880 × 880μm^2.

Design and implementation of an ultra-low power passive UHF RFID tag

This paper presents a fully integrated passive UHF RFID tag chip complying with the ISO18000-6B protocol.The tag chip includes an RF/analog front-end,a baseband processor,and a 512-bit EEPROM memory.To improve power conversion efficiency,a Schottky barrier diode based rectifier is adopted.A novel voltage reference using the peaking current source is discussed in detail,which can meet the low-power,low-voltage requirement while retaining circuit simplicity.Most of the analog blocks are designed to work under sub-1 V to reduce power consumption,and several practical methods are used to further reduce the power consumption of the baseband processor.The whole tag chip is implemented in a TSMC 0.18μm CMOS process with a die size of 800×800μm;. Measurement results show that the total power consumption of the tag chip is only 7.4μW with a sensitivity of -12 dBm.

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。

A passive UHF RFID tag with a dynamic-V_(th)-cancellation rectifier

This paper presents a passive UHF RFID tag with a dynamicVthcancellation （DVC） rectifier. In the rectifier, the threshold voltages of MOSFETs are cancelled by applying gate bias voltages, which are dynamically changed according to the states of the MOSFETs. The DVC rectifier enables both low ONresistance and small re verse leakage of the MOSFETs, resulting in high power conversion efficiency （PCE）. An areaefficient demodulator with a novel average detector is also designed, which takes advantage of the rectifier＇s first stage as the envelope detector. The whole tag chip is implemented in a 0.18 μm CMOS process with a die size of 880 x 950μm2. Measurement results show that the rectifier achieves a maximum PCE of 53.7% with 80 kΩ resistor load.

Design and implementation of a high sensitivity fully integrated passive UHF RFID tag

A fully integrated passive UHF RFID tag complying with the ISO 18000-6B protocol is presented, which includes an analog front-end, a baseband processor, and an EEPROM memory. To extend the communication range, a high efficiency differential-drive CMOS rectifier is adopted. A novel high performance voltage limiter is used to provide a stable limiting voltage, with a 172 mV voltage variation against temperature variation and process dispersion. The dynamic band-enhancement technique is used in the regulator circuit to improve the regulating capacity. A rail-to-rail hysteresis comparator is adopted to demodulate the signal correctly in any condition. The whole transponder chip is implemented in a 0.18μm CMOS process, with a die size of 900 × 800 μm2. Our measurement results show that the total power consumption of the tag chip is only 6.8 μW, with a sensitivity of -13.5 dBm.

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系统的Reader-Tag安全协议的设计及分析

国内外开展了很多加强RFID安全隐私保护的研究,并提出了一系列的方法,如Hash锁、随机Hash锁和Hash链,但这些方法都有一定的缺陷。针对现有方法的不足,并结合现有的方法,设计并分析了一种新的基于RFID系统的Reader-Tag的安全协议。

Tree-based backoff protocol for fast RFID tag identification

This paper proposes a tree-based backoff （TBB） protocol that reduces the number of iterations implemented in the procedure of tag collision arbitration in radio frequency identification （RFID） systems. This is achieved by employing the following mechanisms： one is send the request command iteratively to all tags in the interrogation zone until a single tag is identified. The other is backward to the parent node instead of root node to obtain the request parameters and send the request command again until all tags are identified. Compared with the traditional tree-based protocol, on average, simulated results show that the TBB protocol reduces the number of the iterations by 72.3% and the identification delay by 58.6% and achieves the goal of fast tag identification.

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。

Low-cost low-power UHF RFID tag with on-chip antenna

This paper presents an EPC Class 1 Generation 2 compatible tag with on-chip antenna implemented in the SMIC 0.18 μm standard CMOS process.The UHF tag chip includes an RF/analog front-end, a digital baseband, and a 640-bit EEPROM memory.The on-chip antenna is optimized based on a novel parasitic-aware model.The rectifier is optimized to achieve a power conversion efficiency up to 40% by applying a self-bias feedback and threshold compensation techniques.A good match between the tag circuits and the on-chip antenna is realized by adjusting the rectifier input impedance.Measurements show that the presented tag can achieve a communication range of 1 cm with 1 W reader output power using a 1 × 1 cm2 single-turn loop reader antenna.

A dual-mode secure UHF RFID tag with a crypto engine in 0.13-μm CMOS

An ultra-high-frequency （UHF） radio frequency identification （RFID） secure tag chip with a non-crypto mode and a crypto mode is presented. During the supply chain management, the tag works in the non-crypto mode in which the on-chip crypto engine is not enabled and the tag chip has a sensitivity of-12.8 dBm for long range communication. At the point of sales （POS）, the tag will be switched to the crypto mode in order to protect the privacy of customers. In the crypto mode, an advanced encryption standard （AES） crypto engine is enabled and the sensitivity of the tag chip is switched to ＋2 dBm for short range communication, which is a method of physical protection. The tag chip is implemented and verified in a standard 0.13μm CMOS process.

A passive UHF RFID tag chip with a dual-resolution temperature sensor in a 0.18μm standard CMOS process

This paper presents a passive EPC Gen-2 UHF RFID tag chip with a dual-resolution temperature sensor. The chip tag integrates a temperature sensor, an RF/analog front-end circuit, an NVM memory and a digital base- band in a standard CMOS process. The sensor with a low power sigma-delta （NA） ADC is designed to operate in low and high resolution modes. It can not only achieve the target accuracy but also reduce the power consumption and the sensing time. A CMOS-only RF rectifier and a single-poly non-volatile memory （NVM） are designed to realize a low cost tag chip. The 192-bit-NVM tag chip with an area of 1 mm2 is implemented in a 0.18-#m standard CMOS process. The sensitivity of the tag is -10.7 dBm/-8.4 dBm when the sensor is disabled/enabled. It achieves a maximum reading/sensing distance of 4 m/3.1 m at 2 W EIRR The inaccuracy of the sensor is -0.6 ℃/0.5 ℃ （-1.0 ℃/1.2 ℃） in the operating range from 5 to 15 ℃ in high resolution mode （-30 to 50 ℃ in low resolution mode）. The resolution of the sensor achieves 0.02 ℃ （0.18 ℃） in high （low） resolution mode.