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关键词： 智能家居   阿里云   RFID   多传感器   自动控制   钉钉机器人预警  

摘要： 为了实现家居生活的舒适与安全,设计了一种基于云平台的智能家庭控制系统。建立了RFID智能门禁、室内气体监测与处理,室内土壤监测与自动浇花、系统室内光照监测与自动窗帘、手势识别与自动照明、Web界面显示数据、无线WiFi数据传输等功能于一体的智能家庭控制系统。以MEGA2560为微控制器,将空气质量传感器、光照传感器、土壤湿度传感器、手势识别传感器、环境传感器、射频识别等采集的各项指标数据传输至MCU,并利用编译好的程序进行相应的处理,用于完成由窗帘电机、换气风扇、水泵、电子锁、LED等模块的控制,通过MQTT协议与阿里云平台进行通信,实现Web端数据显示和钉钉机器人的预警。最后通过硬软件的联合调试,结果表明,该系统能够实现多传感器采集、智能控制、云平台监控等功能,具有实用性强、响应快、应用前景较好的特点。

关键词： 室内定位   射频识别   接收信号强度   算法优化   关联度修复   最小目标区域  

摘要： 对RFID室内定位算法LANDMARC存在的问题做了一些优化,针对该算法中存在的局部参考标签关联度异常的情况,对局部不良标签进行关联度修复;针对选取邻近标签过程中易出现的标签误选问题,提出最小目标区域块的改进思路,减少不良标签的影响,再对目标标签位置进行估计。仿真实验结果表明,所提优化方案效果相较于原定位算法具有明显的改善,定位精度提高了22%,其中最大误差减小了27%。

关键词： 柚果   分级入库   库存管理   果框   数字化   RFID技术   信息溯源  

摘要： [目的]针对柚果加工流通企业在库存管理上存在的散货堆垛易损伤,库存分级管理难度大,数字化程度低等问题提出柚果库存分级数字化管理。[方法]基于无线射频识别(RFID)技术,结合柚果分选设备和木制果框设计开发柚果库存分级管理系统,在柚果分选机出果口、环形包装线的出货口加装RFID读写器,并在果框周边加装RFID标签,配套开发数字化平台,以实现柚果的自动分级入库及在库分级管理和销售分级出库;同时基于手持式PDA开发APP应用,便于仓管工作人员对库存管理的实时查询和盘点。[结果]通过5次不同距离的识别试验,得出识别果框最优距离为1.3~1.5 m。在最优识别距离下进行果框入库模拟生产作业,统计各规格柚果入库果框数目,并在每个规格出果口放置40个未入库果框,结果显示入库成功率为100%。在出货口对各规格柚果果框进行出库试验,数据大屏及后台系统显示,柚果信息出库成功率达100%,满足实际工作需要。系统在蜜柚产季的应用数据表明,6种规格柚果3个月统货收购总质量1 145 615 kg,销售统计总质量1 063 699 kg,与企业记录数据相符。系统可详细记录各个规格柚果的入库框数,出库时打印相应的柚果溯源信息;核算出入库数据,系统计算柚果的损耗率仅为7.15%,相对于传统堆垛存储方式(损耗率15%~20%),可大幅降低柚果库存损耗。[结论] 柚果库存分级管理系统可实现柚果的分级入库、在库分级管理、分级出库溯源等功能,可有效提高柚果加工流通企业的工作效率、数字化管理水平和整体效益。

关键词： Modbus-TCP   S7-1500   RFID   模具识别  

摘要： 在冲压生产线中,模具识别通常由PLC读取模具插头中的输入信号后先进行二进制转换编码,然后完成识别。该方法编码接线繁琐,循环利用率低。随着无线通信和智能制造技术的发展,逐渐采用RFID技术应用于模具识别。该技术存储识别信息多、智能化程度高,是一种相对更精准、简便的解决方案。

关键词： 区块链   RFID供应链   所有权转移   中国剩余定理   Pedersen承诺  

摘要： 将产品转移给不受管理员信任的实体,极易造成产品伪造、窜货和隐私泄露等问题.因此,本文提出一种基于区块链的RFID供应链产品所有权转移方案BPOTS.首先,设计了一种基于中国剩余定理与Pedersen承诺的秘密值共享与验证算法,实现了产品在指定新所有者集合的转移,并利用Pedersen承诺的同态性质实现了产品批量转移,提高了产品的转移效率;其次,提出了一种基于对称加密的伪ID生成算法,平衡了供应链的隐私性与透明性;再次,本文对BPOTS进行了安全性分析和性能评估,结果表明:与现有基于区块链的RFID供应链产品所有权转移方案相比,BPOTS有效平衡了供应链的隐私性和透明性,并在产品转移的运行效率上提高了约12倍.最后,本文在长安链平台上实现了所提出的BPOTS并在Github上开源.测试结果表明:BPOTS产品转移效率相比于产品串行转移提高了约70.4%,有效降低了供应链节点的成本.

关键词： Coils   Maximum likelihood estimation   Electric potential   Accuracy   Electric vehicles   Sensors   Vehicle dynamics   Phase detection   Faces   Radiofrequency identification  

摘要： The electric vehicle (EV) has emerged as a transformative force for the sustainable and environmentally friendly future. To alleviate range anxiety caused by the requirement for battery and charging facilities, dynamic wireless power transfer (DWPT) is increasingly recognized as a key enabler for widespread EV adoption, yet it faces significant technical challenges, primarily in precise coil alignment. This article begins by reviewing current alignment methodologies and evaluates their advantages and limitations. We observe that achieving the necessary alignment precision is challenging with these existing methods. To address this, we present an innovative RFID-based DWPT coil alignment system, utilizing coherent phase detection and a maximum likelihood estimation algorithm capable of achieving sub-10 cm accuracy. The efficacy of this system in providing both lateral and vertical misalignment estimates has been verified through laboratory and experimental tests. We also discuss potential challenges in broader system implementation and propose corresponding solutions. This research offers a viable and promising solution for enhancing DWPT efficiency.

关键词： Apis mellifera   Winter bees   Life history traits   Flight activity performance   RFID  

摘要： In temperate regions, the overwintering success of honey bee colonies, Apis mellifera, depends on the last generations of long-lived bees emerging in autumn, known as winter bees. While the physiological qualities of winter bees and their extended lifespan are well documented, yet literature on their flight activity performance is scarce. Here we studied the flight activity of long-lived winter honey bees and compared their performance with short-lived bees. Using radio frequency identification (RFID), we automatically monitored the number of flights, the total flight duration and the lifespan of 523 honey bees that emerged over the course of a year, including short-lived bees from spring, summer and autumn, and long-lived winter bees. We found that flight activity performance of short-lived bees decreased progressively from spring to autumn for both the number of flights and the total flight duration. Furthermore, we confirm that only a fraction of the bees emerging before winter are long-lived winter bees, with a lifespan of 143.5 +/- 23.5 days (mean +/- SD). With an average of 37.5 +/- 44.2 flights and 12.7 +/- 15.5 h of flight, we found that long-lived winter bees were substantially more active than summer and autumn short-lived bees, but performed similar activity than spring short-lived bees. We also found that a small proportion of long-lived winter bees participate in the vast majority of the flight activity of the colony. Our results suggest that the extended lifespan of long-lived winter bees does not affect their flight activity performance, probably explained by their physiological qualities.

关键词： circuit model   electric system   non-contact voltage sensing   power line   RFID   SPICE model   transient solver  

摘要： Monitoring electric power systems is essential for avoiding disruptions, improving efficiency, and detecting faults. Traditional methods involve interrupting the power lines and pose safety risks. On the contrary, non-contact power meters allow for safe power measurement without touching the wires but designing them presents challenges related to battery life and sustainability. This paper introduces a novel battery-less RF-powered wireless circuit that overcomes these limitations and optimizes the performance of the sensing of the voltage. This circuit includes an efficient RF-DC converter, a designed non-contact flexible and curved AC voltage sensor, a signal conditioning circuit, a digital processing unit, and a passive UHF Radio-Frequency Identification interface for wireless communication. It harnesses electromagnetic energy from the radio front end to power the entire system. The circuit has been properly conceptualized, developed, and analyzed through electrical modeling and SPICE simulations. Transient and steady-state analyses have been carefully conducted on individual circuit blocks to analyze their electric characteristics. Finally, a proof-of-concept circuit has been realized and experimentally verified to validate the simulation outcomes. With a bandwidth of 3 kHz, an RF-DC conversion sensitivity of -16 dBm, a current consumption of only 2.2 mA, and an efficient power management procedure, this energy-autonomous, non-contact metering circuit offers very high RF and sensing sensitivities and ultra-low power consumption, making it ideal for monitoring AC electric systems, particularly in inaccessible environments where battery-based solutions are impractical. Architecture of the novel battery-less RF-powered wireless voltage meter optimized to perform accurate voltage sensing from AC insulated wires of electric power lines and electric distribution systems. image

关键词： Lenses   Antenna measurements   Microstrip   Microstrip antenna arrays   Microwave antenna arrays   Europe   Chipless RFID   Technological innovation   Resins   Frequency measurement   3-D printing   additive manufacturing   chipless radio frequency identification   circular economy   lenses   millimeter-wave (mmW) antenna   retrodirective arrays   sustainability   Van Atta arrays  

摘要： In this letter, we present a new method to enhance the radar cross section (RCS) of Van Atta arrays, which can be used in chipless radio frequency identification tags operating in millimeter-wave frequency bands. Small planar low-temperature co-fired ceramic (LTCC) Van Atta arrays, which are durable and can operate in harsh environments, are combined with 3-D printed lenses to increase or modify the shape of their RCS by up to 10 dB. The lenses are uniform in one direction to maintain a wide RCS angular range of the underlying Van Atta arrays. They are manufactured using an affordable 3-D printing stereolithography process using high-performance resin. The resulting manufactured and measured Van Atta retrodirective arrays integrated with lenses exhibit measured RCS levels up to -28 dBsm at 24 GHz frequency. Moreover, the proposed approach allows LTCC Van Atta tags to be easily modified and reused by exchanging their lenses to adapt them to a new application. To the best of the authors' knowledge, this is the first time an experimental evaluation of lenses combined with Van Atta arrays has been presented. This novel technique can also be integrated with other RCS enhancement methods to further increase RCS levels.

关键词： active RFID   wake-up receiver   WuRx   localization device   freight wagon positioning  

摘要： This paper presents the concept, design, and performance analysis of an active radio wake-up and radio identification subsystem as part of an advanced localization device intended to operate within a large-scale freight wagon localization system. The system provides an efficient and cost-effective way to localize freight carriages, which, in the majority of cases, are currently not tracked. The localization device is battery-powered and uses an ultra-low-power radio interface for detecting wake-on-radio signals from nearby operator devices. The same interface is also used for communication within an ad-hoc wireless mesh network, which allows the localization devices to select the best device to send out localization information from the whole cluster through a cellular connection in order to minimize overall battery energy usage. The article presents the overall system architecture construction of the radio interface, including the wake-up subsystem, as well as the results of performance measurements.