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关键词： 光伏巡检   巡检点   RFID   QR-Code   位姿校正  

摘要： 由于光伏发电站视野开阔、场地空旷，光伏阵列环境特征稀疏，相似性高，光伏巡检机器人巡检定位和导航过程中容易因为特征近似出现定位劣化问题。根据光伏电站特性和巡检需求特性，提出一种使用RFID信标和QR-Code标牌为光伏巡检机器人提供巡检点定位与姿态校正信号，实现发生定位劣化后位姿准确校正的方法。并通过巡检点预设巡检采集朝向参数校正巡检台上的设备朝向，调整巡检拍摄视场和角度，为光伏巡检自动识别提供更加有效且易用的巡检数据，在持续的位姿校正过程中保障巡检覆盖率。通过Gazebo仿真测试，对运行的光伏巡检机器人模拟产生定位劣化情况，测试结果表明当发生定位劣化后，光伏巡检机器人可以通过该位姿校正方法，实现位姿校正。通过重复性实验，测得校正成功率超过95%，验证了该方法的有效性，为光伏巡检机器人应用提供了参考。

关键词： RFID   PIT tags   Biotelemetry   Testing protocols  

摘要： BackgroundPassive integrated transponder (PIT) tags are widely used to track animal movements and survival. Rigorous testing protocols are necessary to ensure reliability in PIT tag performance and resulting data across various environmental conditions. This study aimed to document a comprehensive testing framework for PIT tags as a model for the broader biotelemetry community and to showcase how independent evaluations can validate the performance of new PIT tag offerings against established regional performance criteria. Independent testing and adherence to regionally applied standards were key components of this *** Voda IQ HQ12, HQ10, HQ9, and HQ8 PIT tags were evaluated through a series of independent tests, including assessment of physical dimensions, electrical parameter testing, and proximity evaluations. The HQ10 and HQ9 tags passed all performance criteria, while the HQ12 tag excelled in most areas but exceeded the region's maximum weight threshold by 0.0022g. Despite this, the HQ12 tag showed strong detection efficiency and read range, particularly in challenging environments like the Bonneville Corner Collector. The HQ8 tags, while showing a more limited read range, offer advantages in applications requiring minimal tag burden. Independent testing played a crucial role in validating the performance of these tags under established *** study underscores the importance of rigorous testing for PIT tags to ensure reliability across diverse environmental conditions. Independent evaluations like these not only inform stakeholders, but also encourage the adoption of new technologies and vendors. The methods and results presented here offer a valuable model for testing new biotelemetry technologies, applicable across different species, ecosystems, and monitoring programs worldwide.

关键词： anti-collision   RFID   TDMA   DFSA   CA-CFAR  

摘要： Radio Frequency Identification (RFID) is considered a key element of the Internet of Things (IoT). It enables objects to be identified and tracked using radio waves. In RFID systems, several tags may be present within the range of the reader, leading to collisions and interference between signals that reduce system performance. Several anti-collision solutions have been proposed to solve this problem based on TDMA (Time-Division Multiple Access) technique, such as the ALOHA, Slotted ALOHA and Dynamic Framed Slotted ALOHA (DFSA) protocols. In this paper, we propose to improve TDMA anti-collision protocols based on the Cell Averaging Constant False Alarm Rate (CA-CFAR) scheme. The CA-CFAR technique is introduced to estimate the number of tags in the physical layer so that the reader can adjust its transmission parameters accordingly and avoid collisions. The obtained results show that this technique achieves good results in terms of system efficiency and the number of required slots to identify all the tags of the system.

关键词： Strain measurement   RFID   Wireless sensors   Structural health monitoring  

摘要： The advancement of Radio-frequency identification (RFID) sensor technology presents a novel approach to monitoring the health of structures. However, the traditional RFID antenna sensor encounters issues with limited sensitivity and strain measurement capabilities in a single direction. In this investigation, we propose, model, analyze, and test an enhanced wireless and passive RFID strain sensor that offers improved sensitivity to strains and quantifiable measurements in orthogonal directions. Theoretical analysis based on multiphysics elastodynamics and electromagnetics illustrating the resonant response and distribution of current field density between two sets of orthogonally installed sensors under applied stress. Our findings reveal that the RFID strain sensor exhibits characteristics to electromagnetically induced transparency like (EIT-like) effect, enabling independent and intensified measurement of strains both horizontally and vertically. Experimental data demonstrates a linear correlation between the shift in resonant frequency of the sensor antenna and transverse strains as well as longitudinal strains, with sensitivity coefficients measuring -1.76 kHz mu epsilon- 1 for transverse strain and 2.17 kHz mu epsilon- 1 for longitudinal strain respectively. Consequently, by accurately analyzing variations in resonant frequency it becomes possible to deduce both magnitude and direction of strains on the antenna effectively laying groundwork for future engineering applications.

关键词： Sensors   Monitoring   Sensor phenomena and characterization   Antennas   Dipole antennas   Biomedical monitoring   Frequency measurement   Wearable sensors   Radiofrequency identification   Substrates   Antenna-based sensor (ABS)   battery-less   passive   radio frequency identification (RFID) sensor   sweat loss   sweat rate   wearable  

摘要： Emerging applications for wearable sweat loss measuring devices (SLMD) require real-time and long-term operation. These applications impose strict constraints to SLMD in terms of power consumption, size, and flexibility. Several efforts have been made to avoid battery limitations in electronic sensors. However, this remains an open challenge. This contribution presents a battery-less wireless data transfer device enabling sweat loss monitoring through a wearable, flexible, and low-profile antenna-based sensor (ABS). The proposed sensor design includes a small piece of fabric embedded in the antenna substrate to absorb sweat secreted by the skin in contact with the sensor inlet interface. This novel feature dramatically improves the frequency selectivity and frequency range of the ABS in response to the contact with liquids, which increases the measurement accuracy in comparison to the current state of the art, enabling real-time multilevel sweat loss detection. The sensor performance is assessed using a commercial radio frequency identification (RFID) system through laboratory and real-life experiments. The results show that the proposed sensor can track sweat loss within the typical range of the human perspiration rate (300-2100 g/m(2)/h) of healthy individuals using a battery-less and low-cost sensor.

关键词： Sensors   Radiofrequency identification   Coils   Curing   Capacitive sensors   Monitoring   Impedance   Dielectrics   Optical fiber sensors   Manufacturing   Curing monitoring   glass fiber reinforced polymer (GFRP)   interdigital capacitive (IDC) sensor   radio frequency identification (RFID)   time feature extraction  

摘要： In recent years, glass fiber reinforced polymers (GFRPs) have gained widespread adoption across various industrial sectors due to their advantageous properties. As a result, ensuring the production quality of GFRP components and enhancing manufacturing efficiency have become critical priorities to meet the growing demand and performance standards of fiber-reinforced composites. Wireless passive radio frequency identification (RFID) sensing technology has emerged as a valuable tool for monitoring the curing process of GFRP. However, the practical application of this technology is often hindered by the bulkiness of the devices and their susceptibility to interference, which limits their effectiveness in real-world scenarios. In this article, an low-frequency (LF) RFID capacitive sensor, which can be embedded in the GFRP, is proposed for monitoring GFRP curing. The sensor not only monitors subtle changes in electrical properties during the curing of GFRP but also integrates RFID technology for material tracking. This dual approach enhances the reliability of the curing process and ensures consistent high-quality production. The communication and sensing principles of the LF RFID capacitive sensor are described, and the feasibility of the method is analyzed using an equivalent circuit. A interdigital capacitive (IDC) sensor is printed on a flexible circuit board and connected to an RFID tag. The response of the LF RFID capacitive sensor during the curing process of the GFRP was investigated and compared with the measurement results of the dielectric analysis (DEA) method. The experimental results demonstrate the sensor's effectiveness in monitoring the curing process of GFRP, highlighting its potential for real-time assessment in composite manufacturing.

关键词： Resonators   Sensors   Internet of Things   Dielectric constant   Inductance   Semiconductor device measurement   Dielectric measurement   Chipless radio frequency identification (RFID)   dielectric constant   Internet of Things (IoT)   relative permittivity   sensory tag   Walabot  

摘要： Accurate dielectric constant measurements are crucial in Internet of Things (IoT) sensing applications to characterize materials and their properties. This article introduces an innovative capacitor-based chipless radio frequency identification (RFID) sensory array tailored specifically for precise measurements of dielectric constants in IoT contexts. The array incorporates Pi-shaped resonators and cylindrical capacitors, addressing challenges, such as low accuracy, limited $\varepsilon _{r}$ measuring range, and the reliance on bulky vector network analyzers (VNAs) as readers. Theoretical modeling, design considerations, sensor calibration, and validation processes are detailed, highlighting the array's precision and adaptability. Real-world IoT applications are demonstrated, showcasing the array's potential with a low-cost portable multiple-input-multiple-output (MIMO) reader, Walabot. This cost-effective solution overcomes conventional limitations, offering a versatile approach to dielectric constant measurements and opening up new possibilities for diverse IoT sensing applications. The integration of this sensory array with IoT technologies demonstrates the feasibility of smarter material characterization.

摘要： Nowadays attendance is vital in all educational institutes like the schools, colleges and universities, and collecting it is a very tedious job; moreover, the collected data is expected to be precise and accurate. The conventional method included taking attendance using a pen and paper which was inefficient and error prone. Hence an appropriate model should be selected in order to reduce errors. This paper presents attendance system enabled with RFID (Radio Frequency Identification) and smart phone application to collect the attendance. In this system only the teacher will have the RFID card which can be scanned on the system placed in the class. Subsequently a window will open for a short period of time within which all students will have to give their attendance using a mobile application. This can be done from their respective places without having to go to the scanner machine. Proposed system consists of RFID tag, an antenna that can scan the tag, a server and software components. It can be used in working places as well as educational institutes. The system provides real-time, accurate, and secure attendance records allowing administrators to manage attendance effortlessly, improve operational efficiency and can be stored in the form of an excel sheet. This data which will be stored can be further used to calculate percentages and proxy hence making the system efficient, user friendly and secure.

关键词： Frequency hopping  

摘要： Gesture tracking technology provides users with a "hands-free" interactive experience without the need to hold or touch devices. However, current gesture tracking research has primarily focused on tracking accuracy while neglecting issues of user privacy protection and security. This study aims to develop a gesture tracking system based on frequency-hopping RFID signals that effectively protects user privacy without compromising tracking efficiency and accuracy. By introducing frequency-hopping technology, we have designed a mechanism that prevents potential eavesdroppers from obtaining raw RFID signals, thereby enhancing the system’s privacy protection capabilities. The system architecture includes the collection of RFID signals, data processing, signal recovery, and gesture tracking. Experimental results show that our method significantly improves privacy protection levels while maintaining real-time and accuracy. This research not only provides a new perspective for the field of gesture tracking but also offers valuable insights for the use of RFID technology in privacy-sensitive applications. Copyright © 2024, The Authors. All rights reserved.

关键词： Radio frequency identification (RFID)  

摘要： Traveling through toll plazas is one of the primary causes of congestion, according to a recent study that examined these factors [29]. Electronic Toll Collection (ETC) can be set up to reduce the problem. This experiment focuses on improving the security of ETC by RFID tag, and number plate checking. For number plate checking image processing is used where CNN Classifier was implemented in order to detect vehicle registration numbers from the number plate. according to the registered number plate, mail will be sent to the respective owner for paying a toll fee within a certain amount of time to avoid a potential fine. While in this process toll fee will be automatically deducted in real-time from the owner's balance. People who would be waiting in queues to pay tolls would ultimately benefit from this system because no vehicles would slow down, saving them important time and inconvenience while traveling. Copyright © 2024, The Authors. All rights reserved.