International Journal of RF Technologies - Volume Pre-press, issue Pre-press

Authors: Elkhoukhi, H. | Bakhouya, M. | Elmouatamid, A. | El Ouadghiri, D. | Gaber, J.

Article Type: Research Article

Abstract: Comprehensive occupancy information in smart buildings has become more imperative in order to develop new control strategies in energy management systems. Several techniques can be used to collect occupancy information considering accurate sensing techniques, such as passive infrared (PIR), carbon dioxide (CO2) and different types of cameras (i.e., thermal, or optical cameras). Recent studies show the usefulness of integrating occupancy information into energy management systems to reduce energy consumption while maintaining the occupants’ comfort. The purpose of this work is to elaborate a comprehensive review on occupancy detection systems in smart buildings. This study presents a set of comparison standards …including methods, occupancy resolution, type of buildings and sensors. A classification of different approaches, which can be implemented and integrated into the building management system for detecting indoor occupancy, is introduced. Summary and discussions are given by highlighting the usefulness of machine learning for enabling predictive control of active systems in smart buildings. Show more

Keywords: Occupancy detection, occupancy prediction, building energy management systems, data driven methods, machine learning

DOI: 10.3233/RFT-240006

Citation: International Journal of RF Technologies, vol. Pre-press, no. Pre-press, pp. 1-31, 2024

Authors: Xu, Man | Wang, Yunze | Xing, Dan

Article Type: Research Article

Abstract:  This paper proposes an intelligent warehouse-picking approach using radio frequency identification (RFID) indoor positioning and natural language processing (NLP) speech recognition. A forward maximum matching algorithm segments speech into domain terminology. Location was estimated by RFID signal strengths between reference tags and pickers. Simulation results demonstrated a 50% reduction in segmentation runtime versus conventional methods. Speech recognition accuracy reached 90–95%, improving by 23% over baseline. Positioning accuracy also increased substantially. The techniques can reduce picking errors and costs. Further work should evaluate performance in real-world environments.

Keywords: RFID, natural language processing, speech recognition, warehouse picking, LANDMARC algorithm, indoor positioning

DOI: 10.3233/RFT-230055

Citation: International Journal of RF Technologies, vol. Pre-press, no. Pre-press, pp. 1-18, 2024

Authors: Li, Xiaomeng

Article Type: Research Article

Abstract: Real-time monitoring and fault diagnosis of transformers are essential for the stable power system operation. This paper presents an RFID-based transformer fault feature extraction and classification algorithm. Experiments show that monitored current signals are stable while the temperature peak is 356°C. Hilbert decomposition reveals regular current and voltage patterns that can be used as fault indicators. Signal strength classification accuracy reached 80% . At rated load, the transformer temperature soared to 186°C, indicating overheating issues. The monitoring during a sample day showed that overload events were concentrated from 16:00-20:00, which required attention. The approach helps accurately identify transformer fault types …from real-time RFID data for proactive maintenance. Compared to reactive repairs after failures, this not only improves employee productivity but also reduces costs. Based on customized RFID deployment, the algorithm contributes to the stability and economy of power infrastructure. Show more

Keywords: RFID technology, transformer monitoring, fault identification, real time monitoring, power system stability

DOI: 10.3233/RFT-230056

Citation: International Journal of RF Technologies, vol. Pre-press, no. Pre-press, pp. 1-18, 2024

Authors: Vasudevan, Ramya | Nagaraju, V.

Article Type: Research Article

Abstract: This document focuses on the Ultra-Wideband Modified Circular Robo structure Antenna (UWCRSA) with partial ground for the sub-7 GHz band (4.17 GHz to 7 GHz). The overall geometry of the proposed antenna is 12×18×0.8 mm3 . The designed structure is obtained by placing a simple modified circular robotic structure patch with dielectric constant (ɛ r ) and dissipation factor (tanδ ) of 4.4 and 0.02, respectively, on the FR4 substrate. In this document, we examine the design technique, complexity, overall geometric parameters, substrate used, feed technique and performance analysis of the proposed antenna. The semi-grounded radiating patch design is primarily suitable for cellular …vehicle applications and anything below 7 GHz (C – V2X) (IEEE 802.11p standard) and WIFI enhanced 3rd version (IEEE 802.11ac standard). Simulation results for the proposed antenna were generated with a Radio Frequency Structure Simulator (HFSS) and measurements were obtained with a Rohde and Schwarz ZNB 20 network analyzer. Simulation and measurement results are measured in terms of S11, VSWR, bandwidth, gain, directivity, efficiency and radiation pattern. Antenna results show good agreement and can be used for C – V2X, WIFI Extended 3rd Version and satellite communications. Show more

Keywords: Wideband, Sub 7 GHz, C – V2X, WIFI 3rd version, modified circular robo structure antenna

DOI: 10.3233/RFT-230043

Citation: International Journal of RF Technologies, vol. Pre-press, no. Pre-press, pp. 1-18, 2024

Authors: Bottani, Eleonora | Casella, Giorgia | Palmisano, Gaetano | Rizzi, Antonio | Romagnoli, Giovanni | Torreggiani, Federico

Article Type: Research Article

Abstract:  In recent years, an innovative passive Bluetooth Low Energy (BLE) technology, namely Wiliot technology, has emerged as an alternative to passive UHF RFID. This paper proposes an experimental campaign aimed at measuring and evaluating the performance of Wiliot technology, when applied to typical use cases of passive UHF RFID technology. In particular, 9 laboratory tests were conducted to assess read distances, temperature tests, inventory accuracy, and tracking. The results provide interesting feedback, especially regarding reading distances, inventory accuracy, and temperature, suggesting that Wiliot technology could be successfully utilized in these use cases. The tracking tests, however, revealed some limitations, primarily …due to the requirement for the tag to remain stationary in front of the bridge for at least 10–15 seconds to obtain consistent results. Although the number of tests conducted is limited, they represent a first experience with the targeted technology, and the results can be useful to both researchers and practitioners. The former can find suggestions for further tests to enhance the technology and its potential use in real operating environments, while the latter can derive suggestions for possible practical implementations. Show more

Keywords: Wiliot technology, Bluetooth Low Energy (BLE), UHF RFID, performance tests

DOI: 10.3233/RFT-240050

Citation: International Journal of RF Technologies, vol. Pre-press, no. Pre-press, pp. 1-19, 2024