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Electronics
Volume 10
Issue 9
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Electronics, Volume 10, Issue 9 (May-1 2021) – 145 articles

Cover Story (view full-size image): This paper presents the implementation of agent-based architecture suitable for the coordination of power electronic converters in stand-alone microgrids. A publish–subscribe architecture over Distributed Hash Table (DHT) searching overlay is utilized as a distributed microgrid control platform. The developed framework is scalable and set up to deploy power-sharing distributed optimal algorithms while keeping a deterministic time period of a few tens of milliseconds for a system with tens of converters when multiple events might happen concurrently. A notional shipboard system, including several converters, was used as a case study. The simulation results related to applying the agent-based publish–subscribe control system using the Java Agent Development Framework (JADE) are presented. View this paper
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12 pages, 8586 KiB  
Article
Research on an Improved Three-Level SVPWM Modulation Algorithm Based on ID-NPC Topology
by Yonglei Cao and Xiaodong Zhang
Electronics 2021, 10(9), 1129; https://doi.org/10.3390/electronics10091129 - 10 May 2021
Cited by 2 | Viewed by 1671
Abstract
The conventional three-level SVPWM (Space Vector Pulse Width Modulation) algorithm is a basic modulation algorithm, which can be performed easily due to clear modulation ideas. Considering different criteria for sectors, however, the basic vector action time is calculated repeatedly, the selection of vector [...] Read more.
The conventional three-level SVPWM (Space Vector Pulse Width Modulation) algorithm is a basic modulation algorithm, which can be performed easily due to clear modulation ideas. Considering different criteria for sectors, however, the basic vector action time is calculated repeatedly, the selection of vector action sequence is cumbersome, and the algorithm execution time is extended as a result of processing by the digital processing chip. In order to better adapt to the PMSM (Permanent Magnet Synchronous Motor) control requirements of the ID-NPC (Improved Diodes Neutral Point Clamped) topology for converter control objects, the sector judgment part, time effect part and vector synthesis part are optimized according to the principles of saving hardware resources and shortening the execution cycle. The vector synthesis optimization algorithm of 2 × amplitude substitution and the vector synthesis algorithm of 1/2 × amplitude substitution are both proposed. Finally, the ID-NPC topology is used to verify the proposed modulation algorithm. Full article
(This article belongs to the Section Power Electronics)
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18 pages, 4379 KiB  
Article
A Data Transmission Algorithm Based on Triangle Link Structure Prediction in Opportunistic Social Networks
by Zhiyuan Fang, Liu Chang, Jingwen Luo and Jia Wu
Electronics 2021, 10(9), 1128; https://doi.org/10.3390/electronics10091128 - 10 May 2021
Cited by 17 | Viewed by 2099
Abstract
With the popularization of 5G communications, the scale of social networks has grown rapidly, and the types of messages have become increasingly complex. The rapid increases in the number of access nodes and the amount of data have put a greater burden on [...] Read more.
With the popularization of 5G communications, the scale of social networks has grown rapidly, and the types of messages have become increasingly complex. The rapid increases in the number of access nodes and the amount of data have put a greater burden on the transmission of information in the networks. However, when transferring data from a large number of users, the performance of traditional opportunistic network routing algorithms is insufficient, which often leads to problems such as high energy consumption, network congestion, and data packet loss. The way in which to improve this transmission environment has become a difficult task. Therefore, in order to ensure the effective transmission of data and reduce network congestion, this paper proposed a link prediction model based on triangular relationships in opportunistic social networks (LPMBT). In the topological structure of the social network, the algorithm scores links based on the frequency of use and selects the optimal relay node based on the score. It can also efficiently track the target node and reconstruct the sub-community. The simulation experimental results showed that the algorithm had excellent performance, effectively reduced overhead, reduced the end-to-end delay, and greatly improved the data transfer rate in the opportunistic network. Full article
(This article belongs to the Section Networks)
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20 pages, 4820 KiB  
Article
Design and Hardware Implementation of a Simplified DAG-Based Blockchain and New AES-CBC Algorithm for IoT Security
by Sung-Won Lee and Kwee-Bo Sim
Electronics 2021, 10(9), 1127; https://doi.org/10.3390/electronics10091127 - 10 May 2021
Cited by 12 | Viewed by 2917
Abstract
Recently, to enhance the security of the Internet of Things (IoT), research on blockchain-based encryption algorithms has been actively conducted. However, because blockchains have complex structures and process large amounts of data, there are still many difficulties in using the conventional blockchain-based encryption [...] Read more.
Recently, to enhance the security of the Internet of Things (IoT), research on blockchain-based encryption algorithms has been actively conducted. However, because blockchains have complex structures and process large amounts of data, there are still many difficulties in using the conventional blockchain-based encryption algorithms in an IoT system that must have low power consumption and be ultra-lightweight. In this study, to address these problems (1) we simplified the conventional Directed Acyclic Graph (DAG)-based blockchain structure, and (2) we proposed a new Advanced Encryption Standard (AES)-Cipher Block Chaining (CBC) algorithm with enhanced security by periodically changing the secret key and initialization vector (IV) in the conventional AES-CBC encryption algorithm. Because the DAG, which is the conventional blockchain structure, randomly transmits data to multiple blocks, there may be overlapping blocks, and the quantity of transmitted data is not limited; thus, the time and power consumption for encryption and decryption increase. In this study, a simplified DAG was designed to address these problems so that packets can be transmitted only to three blocks, without overlapping. Finally, to verify the effectiveness of the algorithm proposed in this paper, an IoT system consisting of 10 clients and one server was implemented in hardware, and an experiment was conducted. Through the experiment, it was confirmed that when the proposed AES-CBC algorithm was used, the time taken and the amount of power consumed for encryption and decryption were reduced by about 20% compared to the conventional AES-CBC algorithm. Full article
(This article belongs to the Special Issue IoT Security and Privacy through the Blockchain)
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25 pages, 20051 KiB  
Article
Planar-Equirectangular Image Stitching
by Muhammad-Firdaus Syawaludin, Seungwon Kim and Jae-In Hwang
Electronics 2021, 10(9), 1126; https://doi.org/10.3390/electronics10091126 - 10 May 2021
Cited by 3 | Viewed by 3720
Abstract
The 360° cameras have served as a convenient tool for people to record their special moments or everyday lives. The supported panoramic view allowed for an immersive experience with a virtual reality (VR) headset, thus adding viewer enjoyment. Nevertheless, they cannot deliver the [...] Read more.
The 360° cameras have served as a convenient tool for people to record their special moments or everyday lives. The supported panoramic view allowed for an immersive experience with a virtual reality (VR) headset, thus adding viewer enjoyment. Nevertheless, they cannot deliver the best angular resolution images that a perspective camera may support. We put forward a solution by placing the perspective camera planar image onto the pertinent 360° camera equirectangular image region of interest (ROI) through planar-equirectangular image stitching. The proposed method includes (1) tangent image-based stitching pipeline to solve the equirectangular image spherical distortion, (2) feature matching scheme to increase correct feature match count, (3) ROI detection to find the relevant ROI on the equirectangular image, and (4) human visual system (HVS)-based image alignment to tackle the parallax error. The qualitative and quantitative experiments showed improvement of the proposed planar-equirectangular image stitching over existing approaches on a collected dataset: (1) less distortion on the stitching result, (2) 29.0% increased on correct matches, (3) 5.72° ROI position error from the ground truth and (4) lower aggregated alignment-distortion error over existing alignment approaches. We discuss possible improvement points and future research directions. Full article
(This article belongs to the Special Issue LifeXR: Concepts, Technology and Design for Everyday XR)
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20 pages, 8547 KiB  
Article
Power Quality Enhancement in Electric Arc Furnace Using Matrix Converter and Static VAR Compensator
by Bharath Singh Jebaraj, Jaison Bennet, Raju Kannadasan, Mohammed H. Alsharif, Mun-Kyeom Kim, Ayman A. Aly and Mohamed H. Ahmed
Electronics 2021, 10(9), 1125; https://doi.org/10.3390/electronics10091125 - 10 May 2021
Cited by 12 | Viewed by 2400
Abstract
In recent years, non-linear loads on the distribution side are increasing rapidly. Notably, the electric arc furnace (EAF) is the most used non-linear load due to its diverse applications for industrial needs. However, EAF has some disadvantages like uneven distribution of heat inside [...] Read more.
In recent years, non-linear loads on the distribution side are increasing rapidly. Notably, the electric arc furnace (EAF) is the most used non-linear load due to its diverse applications for industrial needs. However, EAF has some disadvantages like uneven distribution of heat inside the furnace, release of unwanted gases, increased level of harmonics, and Flickers in voltages. Specifically, power quality concerns are more and need comprehensive solutions. In this work, a matrix converter (MC) along with static VAR compensator (SVC) is proposed, and the hybrid exponential-hyperbolic furnace model is adapted in MATLAB platform. Simulations are carried out for different cases and the observed results are compared with existing methodologies. It was perceived that the power quality parameters such as peak current and voltages, total harmonic distortions (THDs), voltage flickers, and power factors are enhanced compared with existing methodologies. Precisely, the THD of current and voltage attains a prime rate of about 2.85% and 29.54%, respectively. Moreover, the proposed model’s voltage flicker and power factor offer a grander scale of about 1.26% and 0.9975, respectively. The enhanced scheme provides more significant advantages to the large-scale steel manufacturing plant with EAF. Full article
(This article belongs to the Section Power Electronics)
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20 pages, 853 KiB  
Article
Deflated Restarting of Exponential Integrator Method with an Implicit Regularization for Efficient Transient Circuit Simulation
by Meng Zhang, Jiaxin Li, Chengcheng Yang and Quan Chen
Electronics 2021, 10(9), 1124; https://doi.org/10.3390/electronics10091124 - 10 May 2021
Viewed by 1600
Abstract
Exponential integrator (EI) method based on Krylov subspace approximation is a promising method for large-scale transient circuit simulation. However, it suffers from the singularity problem and consumes large subspace dimensions for stiff circuits when using the ordinary Krylov subspace. Restarting schemes are commonly [...] Read more.
Exponential integrator (EI) method based on Krylov subspace approximation is a promising method for large-scale transient circuit simulation. However, it suffers from the singularity problem and consumes large subspace dimensions for stiff circuits when using the ordinary Krylov subspace. Restarting schemes are commonly applied to reduce the subspace dimension, but they also slow down the convergence and degrade the overall computational efficiency. In this paper, we first devise an implicit and sparsity-preserving regularization technique to tackle the singularity problem facing EI in the ordinary Krylov subspace framework. Next, we analyze the root cause of the slow convergence of the ordinary Krylov subspace methods when applied to stiff circuits. Based on the analysis, we propose a deflated restarting scheme, compatible with the above regularization technique, to accelerate the convergence of restarted Krylov subspace approximation for EI methods. Numerical experiments demonstrate the effectiveness of the proposed regularization technique, and up to 50% convergence improvements for Krylov subspace approximation compared to the non-deflated version. Full article
(This article belongs to the Special Issue Circuit Analysis and Simulation of Modern Electric Systems)
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19 pages, 7842 KiB  
Article
An Advanced Angular Velocity Error Prediction Horizon Self-Tuning Nonlinear Model Predictive Speed Control Strategy for PMSM System
by Yao Wei, Yanjun Wei, Yening Sun, Hanhong Qi and Mengyuan Li
Electronics 2021, 10(9), 1123; https://doi.org/10.3390/electronics10091123 - 10 May 2021
Cited by 7 | Viewed by 1750
Abstract
In nonlinear model predictive control (NMPC), higher accuracy can be obtained with a shorter prediction horizon in steady-state, better dynamics can be obtained with a longer prediction horizon in a transient state, and calculation burden is proportional to the prediction horizon which is [...] Read more.
In nonlinear model predictive control (NMPC), higher accuracy can be obtained with a shorter prediction horizon in steady-state, better dynamics can be obtained with a longer prediction horizon in a transient state, and calculation burden is proportional to the prediction horizon which is usually pre-selected as a constant according to dynamics of the system with NMPC. The minimum calculation and prediction accuracy are hard to ensure for all operating states. This can be improved by an online changing prediction horizon. A nonlinear model predictive speed control (NMPSC) with advanced angular velocity error (AAVE) prediction horizon self-tuning method has been proposed in which the prediction horizon is improved as a discrete-time integer variable and can be adjusted during each sampling period. A permanent magnet synchronous motor (PMSM) rotor position control system with the proposed strategy is accomplished. Tracking performances including rotor position Integral of Time-weighted Absolute value of the Error (ITAE), the maximal delay time, and static error are improved about 15.033%, 23.077%, and 10.294% respectively comparing with the conventional NMPSC strategy with a certain prediction horizon. Better disturbance resisting performance, lower weighting factor sensitivities, and higher servo stiffness are achieved. Simulation and experimental results are given to demonstrate the effectiveness and correctness. Full article
(This article belongs to the Special Issue Advanced Modelling and Control of Complex Nonlinear Mechatronic Systems–Volume II)
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15 pages, 6565 KiB  
Article
A 17.8–34.8 GHz (64.6%) Locking Range Current-Reuse Injection-Locked Frequency Multiplier with Dual Injection Technique
by Kwang-Il Oh, Goo-Han Ko, Gwang-Sub Kim, Jeong-Geun Kim and Donghyun Baek
Electronics 2021, 10(9), 1122; https://doi.org/10.3390/electronics10091122 - 10 May 2021
Cited by 2 | Viewed by 2923
Abstract
A 17.8–34.8 GHz (64.6%) locking range current-reuse injection-locked frequency multiplier (CR-ILFM) with dual injection technique is presented in this paper. A dual injection technique is applied to generate differential signal and increase the power of the second-order harmonic component. The CR core is [...] Read more.
A 17.8–34.8 GHz (64.6%) locking range current-reuse injection-locked frequency multiplier (CR-ILFM) with dual injection technique is presented in this paper. A dual injection technique is applied to generate differential signal and increase the power of the second-order harmonic component. The CR core is proposed to reduce the power consumption and compatibility with NMOS and PMOS injectors. The inductor-capacitor (LC) tank of the proposed CR-ILFM is designed with a fourth-order resonator using a transformer with distributed inductor to extend the locking range. The self-oscillated frequency of the proposed CR-ILFM is 23.82 GHz. The output frequency locking range is 17.8–34.8 GHz (64.6%) at a 0-dBm injection power without any additional control including supply voltage, varactor, and capacitor bank. The power consumption of the proposed CR-ILFM is 7.48 mW from a 1-V supply voltage and the die size is 0.75 mm × 0.45 mm. The CR-ILFM is implemented in a 65-nm CMOS technology. Full article
(This article belongs to the Special Issue Millimeter-Wave Integrated Circuits and Systems for 5G Applications)
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16 pages, 4868 KiB  
Article
Reconfigurable Distributed Power Electronics Technique for Solar PV Systems
by Kamran Ali Khan Niazi, Yongheng Yang, Tamas Kerekes and Dezso Sera
Electronics 2021, 10(9), 1121; https://doi.org/10.3390/electronics10091121 - 10 May 2021
Cited by 4 | Viewed by 2203
Abstract
A reconfiguration technique using a switched-capacitor (SC)-based voltage equalizer differential power processing (DPP) concept is proposed in this paper for photovoltaic (PV) systems at a cell/subpanel/panel-level. The proposed active diffusion charge redistribution (ADCR) architecture increases the energy yield during mismatch and adds a [...] Read more.
A reconfiguration technique using a switched-capacitor (SC)-based voltage equalizer differential power processing (DPP) concept is proposed in this paper for photovoltaic (PV) systems at a cell/subpanel/panel-level. The proposed active diffusion charge redistribution (ADCR) architecture increases the energy yield during mismatch and adds a voltage boosting capability to the PV system under no mismatch by connected the available PV cells/panels in series. The technique performs a reconfiguration by measuring the PV cell/panel voltages and their irradiances. The power balancing is achieved by charge redistribution through SC under mismatch conditions, e.g., partial shading. Moreover, PV cells/panels remain in series under no mismatch. Overall, this paper analyzes, simulates, and evaluates the effectiveness of the proposed DPP architecture through a simulation-based model prepared in PSIM. Additionally, the effectiveness is also demonstrated by comparing it with existing conventional DPP and traditional bypass diode architecture. Full article
(This article belongs to the Special Issue Photovoltaic Energy Systems and Storage)
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8 pages, 1975 KiB  
Article
Antenna on Chip (AoC) Design Using Metasurface and SIW Technologies for THz Wireless Applications
by Ayman A. Althuwayb, Mohammad Alibakhshikenari, Bal S. Virdee, Harry Benetatos, Francisco Falcone and Ernesto Limiti
Electronics 2021, 10(9), 1120; https://doi.org/10.3390/electronics10091120 - 10 May 2021
Cited by 36 | Viewed by 3849
Abstract
This paper presents the design of a high-performance 0.45–0.50 THz antenna on chip (AoC) for fabrication on a 100-micron GaAs substrate. The antenna is based on metasurface and substrate-integrated waveguide (SIW) technologies. It is constituted from seven stacked layers consisting of copper patch–silicon [...] Read more.
This paper presents the design of a high-performance 0.45–0.50 THz antenna on chip (AoC) for fabrication on a 100-micron GaAs substrate. The antenna is based on metasurface and substrate-integrated waveguide (SIW) technologies. It is constituted from seven stacked layers consisting of copper patch–silicon oxide–feedline–silicon oxide–aluminium–GaAs–copper ground. The top layer consists of a 2 × 4 array of rectangular metallic patches with a row of subwavelength circular slots to transform the array into a metasurface. This essentially enlarges the effective aperture area of the antenna. The antenna is excited using a coplanar waveguide feedline that is sandwiched between the two silicon oxide layers below the patch layer. The proposed antenna structure reduces substrate loss and surface waves. The AoC has dimensions of 0.8 × 0.8 × 0.13 mm3. The results show that the proposed structure greatly enhances the antenna’s gain and radiation efficiency, and this is achieved without compromising its physical size. The antenna exhibits an average gain and efficiency of 6.5 dBi and 65%, respectively, which makes it a promising candidate for emerging terahertz applications. Full article
(This article belongs to the Special Issue Advances in System-on-Chip Design)
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16 pages, 5197 KiB  
Article
High-Q Slot Resonator Used in Chipless Tag Design
by Nengyu Huang, Jiaxiang Chen and Zhonghua Ma
Electronics 2021, 10(9), 1119; https://doi.org/10.3390/electronics10091119 - 09 May 2021
Cited by 2 | Viewed by 2375
Abstract
A retransmission chipless tag with multiple U-shaped slot resonators is proposed to cut down the cost of traditional tags with chips. Multiple side-by-side U-shaped slot structures of different lengths are printed on the microstrip line, and the two terminals of the microstrip line [...] Read more.
A retransmission chipless tag with multiple U-shaped slot resonators is proposed to cut down the cost of traditional tags with chips. Multiple side-by-side U-shaped slot structures of different lengths are printed on the microstrip line, and the two terminals of the microstrip line are connected correspondingly with two orthogonal ultra-wideband (UWB) transceiver antennas to form the retransmission chipless tag. The U-shaped slot resonator has high Q values and narrow impedance bandwidth. The bandwidth that each resonator adds to the protection bandwidth is 300 MHz. Several 6-bit coding U-shaped slot resonator chipless tags are designed and fabricated for comparison and measurement. Results show that the simulation and the measurement are in agreement. The slot width of the U-shaped slot resonator and the distance between the resonators are reduced, resulting in deepened spectrum notch depth of the resonator. Decreasing the dielectric constant of the substrate or increasing the thickness of the substrate increases the spectrum notch depth of the resonator. Full article
(This article belongs to the Special Issue Advances in Chipless RFID Technology)
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12 pages, 5546 KiB  
Article
Viewpoint-Aware Action Recognition Using Skeleton-Based Features from Still Images
by Seong-heum Kim and Donghyeon Cho
Electronics 2021, 10(9), 1118; https://doi.org/10.3390/electronics10091118 - 09 May 2021
Cited by 5 | Viewed by 2412
Abstract
In this paper, we propose a viewpoint-aware action recognition method using skeleton-based features from static images. Our method consists of three main steps. First, we categorize the viewpoint from an input static image. Second, we extract 2D/3D joints using state-of-the-art convolutional neural networks [...] Read more.
In this paper, we propose a viewpoint-aware action recognition method using skeleton-based features from static images. Our method consists of three main steps. First, we categorize the viewpoint from an input static image. Second, we extract 2D/3D joints using state-of-the-art convolutional neural networks and analyze the geometric relationships of the joints for computing 2D and 3D skeleton features. Finally, we perform view-specific action classification per person, based on viewpoint categorization and the extracted 2D and 3D skeleton features. We implement two multi-view data acquisition systems and create a new action recognition dataset containing the viewpoint labels, in order to train and validate our method. The robustness of the proposed method to viewpoint changes was quantitatively confirmed using two multi-view datasets. A real-world application for recognizing various actions was also qualitatively demonstrated. Full article
(This article belongs to the Collection Computer Vision and Pattern Recognition Techniques)
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27 pages, 2269 KiB  
Article
On Performance of Sparse Fast Fourier Transform Algorithms Using the Aliasing Filter
by Bin Li, Zhikang Jiang and Jie Chen
Electronics 2021, 10(9), 1117; https://doi.org/10.3390/electronics10091117 - 09 May 2021
Cited by 8 | Viewed by 1962
Abstract
Computing the sparse fast Fourier transform (sFFT) has emerged as a critical topic for a long time because of its high efficiency and wide practicability. More than twenty different sFFT algorithms compute discrete Fourier transform (DFT) by their unique methods so far. In [...] Read more.
Computing the sparse fast Fourier transform (sFFT) has emerged as a critical topic for a long time because of its high efficiency and wide practicability. More than twenty different sFFT algorithms compute discrete Fourier transform (DFT) by their unique methods so far. In order to use them properly, the urgent topic of great concern is how to analyze and evaluate the performance of these algorithms in theory and practice. This paper mainly discusses the technology and performance of sFFT algorithms using the aliasing filter. In the first part, the paper introduces the three frameworks: the one-shot framework based on the compressed sensing (CS) solver, the peeling framework based on the bipartite graph and the iterative framework based on the binary tree search. Then, we obtain the conclusion of the performance of six corresponding algorithms: the sFFT-DT1.0, sFFT-DT2.0, sFFT-DT3.0, FFAST, R-FFAST, and DSFFT algorithms in theory. In the second part, we make two categories of experiments for computing the signals of different SNRs, different lengths, and different sparsities by a standard testing platform and record the run time, the percentage of the signal sampled, and the L0, L1, and L2 errors both in the exactly sparse case and the general sparse case. The results of these performance analyses are our guide to optimize these algorithms and use them selectively. Full article
(This article belongs to the Section Circuit and Signal Processing)
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13 pages, 2887 KiB  
Article
Position Control for Soft Actuators, Next Steps toward Inherently Safe Interaction
by Dongshuo Li, Vaishnavi Dornadula, Kengyu Lin and Michael Wehner
Electronics 2021, 10(9), 1116; https://doi.org/10.3390/electronics10091116 - 09 May 2021
Cited by 9 | Viewed by 2769
Abstract
Soft robots present an avenue toward unprecedented societal acceptance, utility in populated environments, and direct interaction with humans. However, the compliance that makes them attractive also makes soft robots difficult to control. We present two low-cost approaches to control the motion of soft [...] Read more.
Soft robots present an avenue toward unprecedented societal acceptance, utility in populated environments, and direct interaction with humans. However, the compliance that makes them attractive also makes soft robots difficult to control. We present two low-cost approaches to control the motion of soft actuators in applications common in human-interaction tasks. First, we present a passive impedance approach, which employs restriction to pneumatic channels to regulate the inflation/deflation rate of a pneumatic actuator and eliminate the overshoot/oscillation seen in many underdamped silicone-based soft actuators. Second, we present a visual servoing feedback control approach. We present an elastomeric pneumatic finger as an example system on which both methods are evaluated and compared to an uncontrolled underdamped actuator. We perturb the actuator and demonstrate its ability to increase distal curvature around the obstacle and maintain the desired end position. In this approach, we use the continuum deformation characteristic of soft actuators as an advantage for control rather than a problem to be minimized. With their low cost and complexity, these techniques present great opportunity for soft robots to improve human–robot interaction. Full article
(This article belongs to the Special Issue Human Computer Interaction and Its Future)
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12 pages, 5567 KiB  
Article
Temperature-Sensitivity of Two Microwave HEMT Devices: AlGaAs/GaAs vs. AlGaN/GaN Heterostructures
by Mohammad Abdul Alim, Abu Zahed Chowdhury, Shariful Islam, Christophe Gaquiere and Giovanni Crupi
Electronics 2021, 10(9), 1115; https://doi.org/10.3390/electronics10091115 - 09 May 2021
Cited by 13 | Viewed by 3503
Abstract
The goal of this paper is to provide a comparative analysis of the thermal impact on the microwave performance of high electron-mobility transistors (HEMTs) based on GaAs and GaN technologies. To accomplish this challenging goal, the relative sensitivity of the microwave performance to [...] Read more.
The goal of this paper is to provide a comparative analysis of the thermal impact on the microwave performance of high electron-mobility transistors (HEMTs) based on GaAs and GaN technologies. To accomplish this challenging goal, the relative sensitivity of the microwave performance to changes in the ambient temperature is determined by using scattering parameter measurements and the corresponding equivalent-circuit models. The studied devices are two HEMTs with the same gate width of 200 µm but fabricated using different semiconductor materials: GaAs and GaN technologies. The investigation is performed under both cooled and heated conditions, by varying the temperature from −40 °C to 150 °C. Although the impact of the temperature strongly depends on the selected operating condition, the bias point is chosen in order to enable, as much as possible, a fair comparison between the two different technologies. As will be shown, quite similar trends are observed for the two different technologies, but the impact of the temperature is more pronounced in the GaN device. Full article
(This article belongs to the Special Issue Microwave Devices Design and Application)
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14 pages, 974 KiB  
Article
The Pilot Study of the Hazard Perception Test for Evaluation of the Driver’s Skill Using Virtual Reality
by Tatsunori Sawada, Hiroki Uda, Akira Suzuki, Kounosuke Tomori, Kanta Ohno, Hiroki Iga, Yuho Okita and Yoshio Fujita
Electronics 2021, 10(9), 1114; https://doi.org/10.3390/electronics10091114 - 08 May 2021
Cited by 6 | Viewed by 3009
Abstract
Background: Although various technologies are used to evaluate driving skill, there are some limitations such as the limited range of the monitor and the possible risk of causing cybersickness. The purpose of this study is to investigate differences in the hazard perception and [...] Read more.
Background: Although various technologies are used to evaluate driving skill, there are some limitations such as the limited range of the monitor and the possible risk of causing cybersickness. The purpose of this study is to investigate differences in the hazard perception and cybersickness experienced between novice and experienced drivers measured in a VR hazard perception test with a head-mounted display (HMD). Methods: The novice (n = 32) and the experienced drivers (n = 36) participated in the hazard perception test through the VR of an HMD. Results: The total number of identified hazards was 1071 in the novice drivers and 1376 in the experienced drivers. Two of the hazards appeared to be only identifiable through the HMD. A chi-square test revealed that experienced drivers were more likely to identify the hazards than the novice drivers (p < 0.05). The novice drivers appeared to identify “hazard prediction of the current behavior of other road users” more than other hazard types, unlike the experienced group. The Simulator Sickness Questionnaire scores indicated no significant difference in the different age or gender groups (p > 0.05). Conclusion: Our results suggest that the VR hazard perception test may be useful for evaluating patients’ driving skills. Full article
(This article belongs to the Special Issue Virtual-Reality-Based Rehabilitation Technology)
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16 pages, 1039 KiB  
Article
High Precision Multiplier for RNS {2n−1,2n,2n+1}
by Shang Ma, Shuai Hu, Zeguo Yang, Xuesi Wang, Meiqing Liu and Jianhao Hu
Electronics 2021, 10(9), 1113; https://doi.org/10.3390/electronics10091113 - 08 May 2021
Cited by 3 | Viewed by 1897
Abstract
The Residue Number System (RNS) is a non-weighted number system. Benefiting from its inherent parallelism, RNS has been widely studied and used in Digital Signal Processing (DSP) systems and cryptography. However, since the dynamic range in RNS has been fixed by its moduli [...] Read more.
The Residue Number System (RNS) is a non-weighted number system. Benefiting from its inherent parallelism, RNS has been widely studied and used in Digital Signal Processing (DSP) systems and cryptography. However, since the dynamic range in RNS has been fixed by its moduli set, it is hard to solve the overflow problem, which can be easily solved in Two’s Complement System (TCS) by expanding the bit-width of it. For the multiplication in RNS, the traditional way to deal with overflow is to scale down the inputs so that the result can fall in its dynamic range. However, it leads to a loss of precision. In this paper, we propose a high-precision RNS multiplier for three-moduli set 2n−1,2n,2n+1, which is the most used moduli set. The proposed multiplier effectively improves the calculation precision by adding several compensatory items to the result. The compensatory items can be obtained directly from preceding scalers with little extra effort. To the best of our knowledge, we are the first one to propose a high-precision RNS multiplier for the moduli set 2n−1,2n,2n+1. Simulation results show that the proposed RNS multiplier can get almost the same calculation precision as the TCS multiplier with respect to Mean Square Error (MSE) and Signal-to-Noise Ratio(SNR), which outperforms the basic scaling RNS multiplier about 2.6–3 times with respect to SNR. Full article
(This article belongs to the Section Circuit and Signal Processing)
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24 pages, 44883 KiB  
Article
A Gamified Simulator and Physical Platform for Self-Driving Algorithm Training and Validation
by Georgios Pappas, Joshua E. Siegel, Konstantinos Politopoulos and Yongbin Sun
Electronics 2021, 10(9), 1112; https://doi.org/10.3390/electronics10091112 - 08 May 2021
Cited by 10 | Viewed by 3093
Abstract
We identify the need for an easy-to-use self-driving simulator where game mechanics implicitly encourage high-quality data capture and an associated low-cost physical test platform. We design such a simulator incorporating environmental domain randomization to enhance data generalizability and a low-cost physical test platform [...] Read more.
We identify the need for an easy-to-use self-driving simulator where game mechanics implicitly encourage high-quality data capture and an associated low-cost physical test platform. We design such a simulator incorporating environmental domain randomization to enhance data generalizability and a low-cost physical test platform running the Robotic Operating System. A toolchain comprising a gamified driving simulator and low-cost vehicle platform is novel and facilitates behavior cloning and domain adaptation without specialized knowledge, supporting crowdsourced data generation. This enables small organizations to develop certain robust and resilient self-driving systems. As proof-of-concept, the simulator is used to capture lane-following data from AI-driven and human-operated agents, with these data training line following Convolutional Neural Networks that transfer without domain adaptation to work on the physical platform. Full article
(This article belongs to the Section Electrical and Autonomous Vehicles)
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17 pages, 854 KiB  
Article
TA-CLOCK: Tendency-Aware Page Replacement Policy for Hybrid Main Memory in High-Performance Embedded Systems
by Jun Hyeong Choi, Kyung Min Kim and Jong Wook Kwak
Electronics 2021, 10(9), 1111; https://doi.org/10.3390/electronics10091111 - 08 May 2021
Cited by 2 | Viewed by 1936
Abstract
Recently, high-performance embedded systems have adopted phase change memory (PCM) as their main memory because PCMs have attractive advantages, such as non-volatility, byte-addressability, high density, and low power consumption. However, PCMs have disadvantages, such as limited write endurance in each cell and high [...] Read more.
Recently, high-performance embedded systems have adopted phase change memory (PCM) as their main memory because PCMs have attractive advantages, such as non-volatility, byte-addressability, high density, and low power consumption. However, PCMs have disadvantages, such as limited write endurance in each cell and high write latency compared to DRAMs. Therefore, researchers have investigated methods for enhancing the limitations of PCMs. In this paper, we propose a page replacement policy called tendency-aware CLOCK (TA-CLOCK) for the hybrid main memory of embedded systems. To improve the limited write endurance of PCMs, TA-CLOCK classifies the page access tendency of the victim page through access pattern analysis and determines the migration location of the victim page. Through the classification of the page access tendency, TA-CLOCK reduces unnecessary page migrations from DRAMs to PCMs. Unnecessary migrations cause an increase in write operations in PCMs and the energy consumption of the hybrid main memory in embedded systems. Thus, our proposed policy improves the limited write endurance of PCMs and enhances the access latency of the hybrid main memory of embedded systems by classifying the page access tendency. We compared the TA-CLOCK with existing page replacement policies to evaluate its performance. In our experiments, TA-CLOCK reduced the number of write operations in PCMs by 71.5% on average, and it enhanced the energy delay product by 38.3% on average compared with other page replacement policies. Full article
(This article belongs to the Special Issue Storage Systems with Non-volatile Memory Devices)
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15 pages, 4396 KiB  
Article
Analysis of a Resonant Converter with Wide Input Voltage
by Bor-Ren Lin, Alexis Phaik Imm Goh and Kai-Wei Wang
Electronics 2021, 10(9), 1110; https://doi.org/10.3390/electronics10091110 - 08 May 2021
Cited by 2 | Viewed by 1693
Abstract
A DC-DC converter with a 16:1 (Vin,max = 16Vin,min) wide input voltage operation is presented for auxiliary power supplies on solar power conversion circuits or railway vehicles. The solar cell output voltage is associated with the solar intensity [...] Read more.
A DC-DC converter with a 16:1 (Vin,max = 16Vin,min) wide input voltage operation is presented for auxiliary power supplies on solar power conversion circuits or railway vehicles. The solar cell output voltage is associated with the solar intensity (day or night) and geographical location. Thus, the wide input voltage capability of DC converters is required for photovoltaic power conversion. For low power supplies on railway vehicles, the nominal input voltages are 24 V~110 V for the electric door system, motor drive, solid state lighting systems and braking systems. The presented converter uses buck/boost and resonant circuits to achieve the wide input voltage range operation from 18 V to 288 V. If Vin stays on a low input voltage range (18 V~72 V), the buck/boost circuit is operated at a voltage boost characteristic. On the other hand, the buck/boost circuit is operated at a voltage buck characteristic when the input voltage climbs to a high voltage range (72 V~288 V). Thus, the buck/boost circuit can output a constant voltage. Then, the resonant circuit in the second stage is worked at a constant input voltage case so that the frequency variation range is reduced. Finally, to investigate the performance and effectiveness of the studied circuit, experiments with a 500 W prototype were conducted to investigate the performance of the studied circuit. Full article
(This article belongs to the Section Power Electronics)
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36 pages, 12312 KiB  
Article
Optimal Tuning of Fractional Order Controllers for Dual Active Bridge-Based DC Microgrid Including Voltage Stability Assessment
by Mohamed Azab and Alexandre Serrano-Fontova
Electronics 2021, 10(9), 1109; https://doi.org/10.3390/electronics10091109 - 08 May 2021
Cited by 10 | Viewed by 2403
Abstract
In this article, three evolutionary search algorithms: particle swarm optimization (PSO), simulated annealing (SA) and genetic algorithms (GA), have been employed to determine the optimal parameter values of the fractional-order (FO)-PI controllers implemented in the dual active bridge-based (DAB) DC microgrid. The optimum [...] Read more.
In this article, three evolutionary search algorithms: particle swarm optimization (PSO), simulated annealing (SA) and genetic algorithms (GA), have been employed to determine the optimal parameter values of the fractional-order (FO)-PI controllers implemented in the dual active bridge-based (DAB) DC microgrid. The optimum strategy to obtain the parameters of these FO-PI controllers is still a major challenge for many power systems applications. The FO-PI controllers implemented in the DAB are used to control the DC link voltage to the desired value and limit the current flowing through the converter. Accordingly, the investigated control system has six parameters to be tuned simultaneously; Kp1, Ki1, λ1 for FO-PI voltage controller and Kp2, Ki2, λ2 for FO-PI current controller. Crucially, this tuning optimization process has been developed to enhance the voltage stability of a DC microgrid. By observing the frequency-domain analysis of the closed-loop and the results of the subsequent time-domain simulations, it has been demonstrated that the evolutionary algorithms have provided optimal controller gains, which ensures the voltage stability of the DC microgrid. The main contribution of the article can be considered in the successful application of evolutionary search algorithms to tune the parameters of FO-based dual loop controllers of a DC microgrid scheme whose power conditioner is a DAB topology. Full article
(This article belongs to the Special Issue Power Converters Technologies in Power Electronics)
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35 pages, 12257 KiB  
Review
Review of Power Converter Impact of Electromagnetic Energy Harvesting Circuits and Devices for Autonomous Sensor Applications
by Mahidur R. Sarker, Mohamad Hanif Md Saad, José Luis Olazagoitia and Jordi Vinolas
Electronics 2021, 10(9), 1108; https://doi.org/10.3390/electronics10091108 - 08 May 2021
Cited by 28 | Viewed by 4428
Abstract
The demand for power is increasing due to the rapid growth of the population. Therefore, energy harvesting (EH) from ambient sources has become popular. The reduction of power consumption in modern wireless systems provides a basis for the replacement of batteries with the [...] Read more.
The demand for power is increasing due to the rapid growth of the population. Therefore, energy harvesting (EH) from ambient sources has become popular. The reduction of power consumption in modern wireless systems provides a basis for the replacement of batteries with the electromagnetic energy harvesting (EMEH) approach. This study presents a general review of the EMEH techniques for autonomous sensor (ATS) applications. Electromagnetic devices show great potential when used to power such ATS technologies or convert mechanical energy to electrical energy. As its power source, this stage harvests ambient energy and features a self-starting and self-powered process without the use of batteries. Therefore, it consumes low power and is highly stable for harvesting energy from the environment with low ambient energy sources. The review highlights EMEH circuits, low power EMEH devices, power electronic converters, and controllers utilized in numerous applications, and described their impacts on energy conservation, benefits, and limitation. This study ultimately aims to suggest a smart, low-voltage electronic circuit for a low-power sensor that harvests electromagnetic energy. This review also focuses on various issues and suggestions of future EMEH for low power autonomous sensors. Full article
(This article belongs to the Section Power Electronics)
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32 pages, 1895 KiB  
Article
Improving Security of Future Networks Using Enhanced Customer Edge Switching and Risk-Based Analysis
by Slawomir Nowaczewski and Wojciech Mazurczyk
Electronics 2021, 10(9), 1107; https://doi.org/10.3390/electronics10091107 - 08 May 2021
Viewed by 1673
Abstract
Customer Edge Switching (CES) is an extension of the already known classical firewall that is often described and used in future networks like 5G. It extends its functionality by enabling information exchange with other firewalls to decide whether the inspected network traffic should [...] Read more.
Customer Edge Switching (CES) is an extension of the already known classical firewall that is often described and used in future networks like 5G. It extends its functionality by enabling information exchange with other firewalls to decide whether the inspected network traffic should be considered malicious or legitimate. In this paper, we show how the Passive DNS can be used to further improve security of this solution. First, we discuss CES solution and its internals. We also determine how it uses DNS and CETP protocols. Secondly, we describe the basics of the Passive DNS and how it impacts the DNS protocol. Thirdly, we evaluate how the Passive DNS can be extended to collect also CETP information. Finally, we integrate the solutions and present obtained experimental results. Full article
(This article belongs to the Special Issue Cybersecurity and Mobility in 5G and Beyond)
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24 pages, 3854 KiB  
Article
Flexible 5G New Radio LDPC Encoder Optimized for High Hardware Usage Efficiency
by Vladimir L. Petrović, Dragomir M. El Mezeni and Andreja Radošević
Electronics 2021, 10(9), 1106; https://doi.org/10.3390/electronics10091106 - 08 May 2021
Cited by 19 | Viewed by 4225
Abstract
Quasi-cyclic low-density parity-check (QC–LDPC) codes are introduced as a physical channel coding solution for data channels in 5G new radio (5G NR). Depending on the use case scenario, this standard proposes the usage of a wide variety of codes, which imposes the need [...] Read more.
Quasi-cyclic low-density parity-check (QC–LDPC) codes are introduced as a physical channel coding solution for data channels in 5G new radio (5G NR). Depending on the use case scenario, this standard proposes the usage of a wide variety of codes, which imposes the need for high encoder flexibility. LDPC codes from 5G NR have a convenient structure and can be efficiently encoded using forward substitution and without computationally intensive multiplications with dense matrices. However, the state-of-the-art solutions for encoder hardware implementation can be inefficient since many hardware processing units stay idle during the encoding process. This paper proposes a novel partially parallel architecture that can provide high hardware usage efficiency (HUE) while achieving encoder flexibility and support for all 5G NR codes. The proposed architecture includes a flexible circular shifting network, which is capable of shifting a single large bit vector or multiple smaller bit vectors depending on the code. The encoder architecture was built around the shifter in a way that multiple parity check matrix elements can be processed in parallel for short codes, thus providing almost the same level of parallelism as for long codes. The processing schedule was optimized for minimal encoding time using the genetic algorithm. The optimized encoder provided high throughputs, low latency, and up-to-date the best HUE. Full article
(This article belongs to the Special Issue VLSI Architectures for Wireless Communications and Digital Signal Processing)
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10 pages, 2158 KiB  
Article
Analysis of Non-Idealities on CMOS Passive Mixers
by Antonio D. Martinez-Perez, Francisco Aznar, Guillermo Royo and Santiago Celma
Electronics 2021, 10(9), 1105; https://doi.org/10.3390/electronics10091105 - 08 May 2021
Viewed by 2118
Abstract
In the current state of the art, WiFi-alike standards require achieving a high Image Rejection Ratio (IRR) while having low power consumption. Thus, quadrature structures based on passive ring mixers offer an attractive and widely used solution, as they can achieve a high [...] Read more.
In the current state of the art, WiFi-alike standards require achieving a high Image Rejection Ratio (IRR) while having low power consumption. Thus, quadrature structures based on passive ring mixers offer an attractive and widely used solution, as they can achieve a high IRR while being a passive block. However, it is not easy for the designer to know when a simple quadrature scheme is enough and when they should aim for a double quadrature structure approach, as the latter can improve the performance at the cost of requiring more area and complexity. This study focuses on the IRR, which crucially depends on the symmetry between the I and Q branches. Non-idealities (component mismatches, parasitics, etc.) will degrade the ideal balance by affecting the mixer and/or following/previous stages. This paper analyses the effect of imbalances, providing the constraints for obtaining a 40 dB IRR in the case of a conversion from a one-hundred-megahertz signal to the five-gigahertz range (upconversion) and vice versa (downconversion) for simple and double quadrature schemes. All simulations were carried out with complete device models from 65 nm standard CMOS technology and also a post-layout Monte Carlo analysis was included for mismatch analysis. The final section includes guidelines to help designers choose the most adequate scheme for each case. Full article
(This article belongs to the Section Circuit and Signal Processing)
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18 pages, 832 KiB  
Article
Memory-Efficient Deep Learning for Botnet Attack Detection in IoT Networks
by Segun I. Popoola, Bamidele Adebisi, Ruth Ande, Mohammad Hammoudeh and Aderemi A. Atayero
Electronics 2021, 10(9), 1104; https://doi.org/10.3390/electronics10091104 - 08 May 2021
Cited by 23 | Viewed by 2520
Abstract
Cyber attackers exploit a network of compromised computing devices, known as a botnet, to attack Internet-of-Things (IoT) networks. Recent research works have recommended the use of Deep Recurrent Neural Network (DRNN) for botnet attack detection in IoT networks. However, for high feature dimensionality [...] Read more.
Cyber attackers exploit a network of compromised computing devices, known as a botnet, to attack Internet-of-Things (IoT) networks. Recent research works have recommended the use of Deep Recurrent Neural Network (DRNN) for botnet attack detection in IoT networks. However, for high feature dimensionality in the training data, high network bandwidth and a large memory space will be needed to transmit and store the data, respectively in IoT back-end server or cloud platform for Deep Learning (DL). Furthermore, given highly imbalanced network traffic data, the DRNN model produces low classification performance in minority classes. In this paper, we exploit the joint advantages of Long Short-Term Memory Autoencoder (LAE), Synthetic Minority Oversampling Technique (SMOTE), and DRNN to develop a memory-efficient DL method, named LS-DRNN. The effectiveness of this method is evaluated with the Bot-IoT dataset. Results show that the LAE method reduced the dimensionality of network traffic features in the training set from 37 to 10, and this consequently reduced the memory space required for data storage by 86.49%. SMOTE method helped the LS-DRNN model to achieve high classification performance in minority classes, and the overall detection rate increased by 10.94%. Furthermore, the LS-DRNN model outperformed state-of-the-art models. Full article
(This article belongs to the Section Networks)
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26 pages, 1398 KiB  
Article
Flickering-Free Distance-Independent Modulation Scheme for OCC
by Patricia Chavez-Burbano, Jose Rabadan, Victor Guerra and Rafael Perez-Jimenez
Electronics 2021, 10(9), 1103; https://doi.org/10.3390/electronics10091103 - 08 May 2021
Cited by 5 | Viewed by 1723
Abstract
Communications for IoT sensor networks in Smart City applications are demanding new technologies to avoid the radio frequency spectrum saturation and support the massive nodes situation required in this kind of network. Visible Light Communications are gaining interest as an alternative scheme for [...] Read more.
Communications for IoT sensor networks in Smart City applications are demanding new technologies to avoid the radio frequency spectrum saturation and support the massive nodes situation required in this kind of network. Visible Light Communications are gaining interest as an alternative scheme for solving this problem. In particular, Optical Camera Communication (OCC) takes advantage of the presence of cameras in a wide range of devices (smartphones, surveillance systems). Several transmission and modulation schemes, specifically developed for OCC, have been proposed but they present different problems as the communication range, the flickering effects in the transmitted signal, or the system complexity. In this work, an Optical Camera Communication modulation scheme that addresses the considerable variability of the transmitter–receiver distance is proposed. As will be shown, the modulation scheme works properly independently of this separation for a wide range of distances. Additionally, it performs a flickering free transmission to avoid undesired blinking effects for humans and uses a simplified transmission and reception scheme, reducing the system complexity and cost. Results of the modulation’s performance for short (<20 m), medium (20–60 m), and long (>60 m) ranges are presented in the paper, showing a 16 bps transmission rate with Bit Error Rate below the Forward Error Correction (FEC) limit (3.8 · 10−3). Full article
(This article belongs to the Special Issue Visible Light Communications Technology and Its Applications)
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16 pages, 3465 KiB  
Article
Lane Line Detection Based on Object Feature Distillation
by Malik Haris and Adam Glowacz
Electronics 2021, 10(9), 1102; https://doi.org/10.3390/electronics10091102 - 08 May 2021
Cited by 21 | Viewed by 2695
Abstract
In order to meet the real-time requirements of the autonomous driving system, the existing method directly up-samples the encoder’s output feature map to pixel-wise prediction, thus neglecting the importance of the decoder for the prediction of detail features. In order to solve this [...] Read more.
In order to meet the real-time requirements of the autonomous driving system, the existing method directly up-samples the encoder’s output feature map to pixel-wise prediction, thus neglecting the importance of the decoder for the prediction of detail features. In order to solve this problem, this paper proposes a general lane detection framework based on object feature distillation. Firstly, a decoder with strong feature prediction ability is added to the network using direct up-sampling method. Then, in the network training stage, the prediction results generated by the decoder are regarded as soft targets through knowledge distillation technology, so that the directly up-samples branch can learn more detailed lane information and have a strong feature prediction ability for the decoder. Finally, in the stage of network inference, we only need to use the direct up-sampling branch instead of the forward calculation of the decoder, so compared with the existing model, it can improve the lane detection performance without additional cost. In order to verify the effectiveness of this framework, it is applied to many mainstream lane segmentation methods such as SCNN, DeepLabv1, ResNet, etc. Experimental results show that, under the condition of no additional complexity, the proposed method can obtain higher F1Measure on CuLane dataset. Full article
(This article belongs to the Section Artificial Intelligence)
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41 pages, 24621 KiB  
Article
Optimal Identification and Metaheuristic PID Control of a Two-Tank System
by Dan Stefanoiu and Janetta Culita
Electronics 2021, 10(9), 1101; https://doi.org/10.3390/electronics10091101 - 07 May 2021
Cited by 3 | Viewed by 2491
Abstract
In the modern optimization context, this paper introduces an optimal PID-based control strategy for a two-tank installation, namely ASTANK2. The process model was identified by using raw and spline smoothed measured data, respectively. Two PID controller configurations, a standard (regular) one (PID-R) and [...] Read more.
In the modern optimization context, this paper introduces an optimal PID-based control strategy for a two-tank installation, namely ASTANK2. The process model was identified by using raw and spline smoothed measured data, respectively. Two PID controller configurations, a standard (regular) one (PID-R) and a non-standard one (PID-N), were considered for each type of model, resulting in four regulators. The optimal tuning parameters of each regulator were obtained by a searching approach relying on a combination of two metaheuristics. Firstly, an improved version of the Hill Climbing algorithm was employed to comprehensively explore the searching space, aiming to find fairly accurate tuning parameters. Secondly, an improved version of the Firefly Algorithm was proposed to intensively refine the search around the previously found optimal parameters. A comparative analysis between the four controllers was achieved in terms of performance and robustness. The simulation results showed that all optimal controllers yielded good performance in the presence of exogenous stochastic noise (bounded error tracking, setpoint tracking, reduced overshoot, short settling time). Robustness analysis is extensive and illustrates that the PID-R controllers are more robust to model uncertainties, whilst PID-N controllers are more robust to tracking staircase type references. Full article
(This article belongs to the Special Issue Control of Nonlinear Systems and Industrial Processes)
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15 pages, 4978 KiB  
Article
Temperature Measurement at Curved Surfaces Using 3D Printed Planar Resistance Temperature Detectors
by Adam Steckiewicz, Kornelia Konopka, Agnieszka Choroszucho and Jacek Maciej Stankiewicz
Electronics 2021, 10(9), 1100; https://doi.org/10.3390/electronics10091100 - 07 May 2021
Cited by 5 | Viewed by 1984
Abstract
In this article, novel 3D printed sensors for temperature measurement are presented. A planar structure of the resistive element is made, utilizing paths of a conductive filament embedded in an elastic base. Both electrically conductive and flexible filaments are used simultaneously during the [...] Read more.
In this article, novel 3D printed sensors for temperature measurement are presented. A planar structure of the resistive element is made, utilizing paths of a conductive filament embedded in an elastic base. Both electrically conductive and flexible filaments are used simultaneously during the 3D printing procedure, to form a ready–to–use measuring device. Due to the achieved flexibility, the detectors may be used on curved and irregular surfaces, with no concern for their possible damage. The geometry and properties of the proposed resistance detectors are discussed, along with a printing procedure. Numerical models of considered sensors are characterized, and the calculated current distributions as well as equivalent resistances of the different structures are compared. Then, a nonlinear influence of temperature on the resistance is experimentally determined for the exemplary planar sensors. Based on these results, using first–order and hybrid linear–exponential approximations, the analytical formulae are derived. Additionally, the device to measure an average temperature from several measuring surfaces is considered. Since geometry of the sensor can be designed utilizing presented approach and printed by applying fused deposition modeling, the functional device can be customized to individual needs. Full article
(This article belongs to the Special Issue Wearable and Flexible Integrated Sensors)
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