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Electronics
Volume 11
Issue 7
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Electronics, Volume 11, Issue 7 (April-1 2022) – 194 articles

Cover Story (view full-size image): The design of a thin 2 × 2 CP slot array antenna was presented for a high-band UWB application. The proposed antenna is composed of three parts: a top metal part that consists of an L-shaped slot structure, a dielectric substrate, and a bottom floating metal layer. The prototype antenna size is 29.2 mm × 31.7 mm, and its thickness is 1.636 mm. The measurement results show a maximum gain of 6.94 dBic at 9.02 GHz, whereas that of the 3 dB gain-band was 900 MHz (8.55–9.45 GHz). These results suggest that the proposed CP thin antenna with high gain is qualified to be used in high-band UWB applications. View this paper
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18 pages, 1468 KiB  
Article
Reducing Redundant Test Executions in Software Product Line Testing—A Case Study
by Pilsu Jung, Sungwon Kang and Jihyun Lee
Electronics 2022, 11(7), 1165; https://doi.org/10.3390/electronics11071165 - 6 Apr 2022
Cited by 6 | Viewed by 2365
Abstract
In the context of software product line (SPL) engineering, test cases can be reused for testing a family of products that share common parts of source code. An approach to test the products of a product family is to exhaustively execute each test [...] Read more.
In the context of software product line (SPL) engineering, test cases can be reused for testing a family of products that share common parts of source code. An approach to test the products of a product family is to exhaustively execute each test case on all the products. However, such an approach would be very inefficient because the common parts of source code will be tested multiple times unnecessarily. To reduce unnecessary repetition of testing, we previously proposed a method to avoid equivalent test executions of a product line in the context of regression testing. However, it turns out that the same approach can be used in a broader context than just regression testing of product families. In this paper, we argue the generality of the method in the sense that it can be used for testing of the first version of a product family as well as regression testing of its subsequent versions. In addition, in this paper, in order to make the method practically usable for users, we propose a process for applying it to SPL testing. We demonstrate the generality of our method and the practical applicability of the proposed process for the method by conducting a case study. Full article
(This article belongs to the Section Computer Science & Engineering)
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18 pages, 4528 KiB  
Article
P-Ride: A Shareability Prediction Based Framework in Ridesharing
by Yu Chen and Liping Wang
Electronics 2022, 11(7), 1164; https://doi.org/10.3390/electronics11071164 - 6 Apr 2022
Cited by 3 | Viewed by 1736
Abstract
Ridesharing services aim to reduce travel costs for users and optimize revenue for drivers and platforms by sharing available seats. Existing works can be roughly classified into two types, i.e., online-based and batch-based methods. The former mainly focuses on responding quickly to the [...] Read more.
Ridesharing services aim to reduce travel costs for users and optimize revenue for drivers and platforms by sharing available seats. Existing works can be roughly classified into two types, i.e., online-based and batch-based methods. The former mainly focuses on responding quickly to the requests, and the latter focuses on meticulously enumerating request combinations to improve service quality. However, online-based methods perform poorly in service quality due to the neglect of the sharing relationship between requests, while batch-based methods fail in terms of efficiency. To obtain better service quality more efficiently, we propose a shareability prediction-based framework P-Ride. Specifically, we first introduce the k-clique listing strategy in graph theory based on the shareability graph to reduce the infeasible request combinations. Moreover, we extend the shareability graph to the hypergraph structure to represent the higher-order shareable relationships among requests. Furthermore, we devise a shareability prediction model that supports the prediction of sharable relationships for request combinations of an arbitrary size, which helps further filtering of candidate request combinations with GPU devices acceleration. The extensive experimental results demonstrate the efficiency and effectiveness of our proposed P-Ride framework. Full article
(This article belongs to the Topic Intelligent Transportation Systems)
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16 pages, 8219 KiB  
Article
On-Orbit Experimental Result of a Non-Deployable 430-MHz-Band Antenna Using a 1U CubeSat Structure
by Daisuke Nakayama, Takashi Yamauchi, Hirokazu Masui, Sangkyun Kim, Kazuhiro Toyoda, Tharindu Lakmal Dayarathna Malmadayalage, Mengu Cho and the BIRDS-4 Project Team
Electronics 2022, 11(7), 1163; https://doi.org/10.3390/electronics11071163 - 6 Apr 2022
Cited by 4 | Viewed by 2644
Abstract
1U CubeSats often use the 430-MHz band for communication due to their size and power limitations, and half-wavelength dipole antennas are employed. A 430-MHz-band dipole antenna requires a deployable structure for a 1U CubeSat. However, a 1U CubeSat has a small volume margin [...] Read more.
1U CubeSats often use the 430-MHz band for communication due to their size and power limitations, and half-wavelength dipole antennas are employed. A 430-MHz-band dipole antenna requires a deployable structure for a 1U CubeSat. However, a 1U CubeSat has a small volume margin for redundant systems, so the antenna deployment system can be a single point of failure. In this paper, the 1U CubeSat structure itself was used as an antenna. As a sub-mission of the BIRDS-4 project, three 1U CubeSats (GuaraniSat-1, Maya-2, and Tsuru) demonstrated this antenna structure. The results of the ground tests showed a maximum gain of −5.7 dBi with the flight model. These satellites were deployed from the International Space Station on 14 March 2021. Radio signals were alternately transmitted from the dipole antenna and the structure antenna onboard Tsuru for on-orbit demonstration on 15 December 2021, and the received signal strength on the ground was compared using RTL-SDR, SDR# and several codes. The ground station was able to receive both dipole and structure CW signals. The received power strength indicates that a gain of −8.1 dBi is being demonstrated with the structure antenna. Full article
(This article belongs to the Special Issue Antenna Developments for Small Satellites and CubeSats)
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16 pages, 1175 KiB  
Article
Safety System Assessment Case Study of Automated Vehicle Shuttle
by Heiko Pikner, Raivo Sell, Jüri Majak and Kristo Karjust
Electronics 2022, 11(7), 1162; https://doi.org/10.3390/electronics11071162 - 6 Apr 2022
Cited by 13 | Viewed by 2886
Abstract
Automated vehicle (AV) minibuses, i.e., AV shuttles, are gaining popularity in the testing of new types of transportation services in real traffic conditions. AV shuttles have moved from closed test areas to low-traffic public sites such as local residential areas, technology parks, university [...] Read more.
Automated vehicle (AV) minibuses, i.e., AV shuttles, are gaining popularity in the testing of new types of transportation services in real traffic conditions. AV shuttles have moved from closed test areas to low-traffic public sites such as local residential areas, technology parks, university campuses, etc. These types of vehicles are usually low-speed and rely on a lidar-camera sensor set and a self-driving software stack. These new use cases are increasing these systems’ safety demands. In addition to functional safety, many other aspects need to be considered. In this study, a risk analysis model is developed, combining the fuzzy analytical hierarchy process and the Technique for Order of Preference by Similarity to Ideal Solution method. The proposed model is utilized to prioritize risks corresponding to the particular case study, based on real AV shuttle bus development, and focuses on the low-level hardware/software safety issues and improvements. Full article
(This article belongs to the Special Issue Cyber-Physical Systems in Smart Cities)
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11 pages, 399 KiB  
Article
Feasibility Prediction for Rapid IC Design Space Exploration
by Riadul Islam
Electronics 2022, 11(7), 1161; https://doi.org/10.3390/electronics11071161 - 6 Apr 2022
Cited by 4 | Viewed by 2556
Abstract
The DARPA POSH program echoes with the research community and identifies that engineering productivity has fallen behind Moore’s law, resulting in the prohibitive increase in IC design cost at leading technology nodes. The primary reason is that it requires many computing resources, expensive [...] Read more.
The DARPA POSH program echoes with the research community and identifies that engineering productivity has fallen behind Moore’s law, resulting in the prohibitive increase in IC design cost at leading technology nodes. The primary reason is that it requires many computing resources, expensive tools, and even many days to complete a design implementation. However, at the end of this process, some designs could not meet the design constraints and become unroutable, creating a vicious circuit design cycle. As a result, designers have to re-run the whole process after design modification. This research applied a machine learning approach to automatically identify design constraints and design rule checking (DRC) violation issues and help the designer identify design constraints with optimal DRCs before the long detailed routing process through iterative greedy search. The proposed algorithm achieved up to 99.99% design constraint prediction accuracy and reduced 98.4% DRC violations with only a 6.9% area penalty. Full article
(This article belongs to the Section Circuit and Signal Processing)
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21 pages, 3553 KiB  
Review
A Review on SIW and Its Applications to Microwave Components
by Augustine O. Nwajana and Emenike Raymond Obi
Electronics 2022, 11(7), 1160; https://doi.org/10.3390/electronics11071160 - 6 Apr 2022
Cited by 37 | Viewed by 11500
Abstract
Substrate-integrated waveguide (SIW) is a modern day (21st century) transmission line that has recently been developed. This technology has introduced new possibilities to the design of efficient circuits and components operating in the radio frequency (RF) and microwave frequency spectrum. Microstrip components are [...] Read more.
Substrate-integrated waveguide (SIW) is a modern day (21st century) transmission line that has recently been developed. This technology has introduced new possibilities to the design of efficient circuits and components operating in the radio frequency (RF) and microwave frequency spectrum. Microstrip components are very good for low frequency applications but are ineffective at extreme frequencies, and involve rigorous fabrication concessions in the implementation of RF, microwave, and millimeter-wave components. This is due to wavelengths being short at higher frequencies. Waveguide devices, on the other hand, are ideal for higher frequency systems, but are very costly, hard to fabricate, and challenging to integrate with planar components in the neighborhood. SIW connects the gap that existed between conventional air-filled rectangular waveguide and planar transmission line technologies including the microstrip. This study explores the current advancements and new opportunities in SIW implementation of RF and microwave devices including filters, multiplexers (diplexers and triplexers), power dividers/combiners, antennas, and sensors for modern communication systems. Full article
(This article belongs to the Section Microwave and Wireless Communications)
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13 pages, 16357 KiB  
Article
Fuzzy Compensation and Load Disturbance Adaptive Control Strategy for Electro-Hydraulic Servo Pump Control System
by Yu Song, Zhongwang Hu and Chao Ai
Electronics 2022, 11(7), 1159; https://doi.org/10.3390/electronics11071159 - 6 Apr 2022
Cited by 10 | Viewed by 2323
Abstract
Aiming at the high-precision position control of electro-hydraulic servo pump control system, a compensation control algorithm based on fuzzy control theory is proposed based on the classical PID control algorithm for the control of factors such as oil compression and system leakage. Firstly, [...] Read more.
Aiming at the high-precision position control of electro-hydraulic servo pump control system, a compensation control algorithm based on fuzzy control theory is proposed based on the classical PID control algorithm for the control of factors such as oil compression and system leakage. Firstly, a mathematical model of the system was established, and online identification of load disturbance was carried out. Then, oil compression and system leakage compensation controllers were established, and the position error caused by the load disturbance was compensated based on fuzzy control rules. Finally, the position control effect was verified using an experimental platform. The results show that the load disturbance compensation control strategy can significantly reduce the influence of load disturbance of the system. The steady-state accuracy of the system reached ±0.01 mm, which significantly enhanced the anti-disturbance ability of the system. Full article
(This article belongs to the Topic Advanced Systems Engineering: Theory and Applications)
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23 pages, 10522 KiB  
Review
Research and Application of Capacitive Power Transfer System: A Review
by Zhulin Wang, Yiming Zhang, Xinghong He, Bo Luo and Ruikun Mai
Electronics 2022, 11(7), 1158; https://doi.org/10.3390/electronics11071158 - 6 Apr 2022
Cited by 25 | Viewed by 10391
Abstract
Capacitive power transfer (CPT) uses an electric field as the transfer medium to achieve wireless power transfer (WPT). Benefitting from the low eddy current loss, simple system structure and strong plasticity of the coupling coupler, the CPT system has recently gained much attention. [...] Read more.
Capacitive power transfer (CPT) uses an electric field as the transfer medium to achieve wireless power transfer (WPT). Benefitting from the low eddy current loss, simple system structure and strong plasticity of the coupling coupler, the CPT system has recently gained much attention. The CPT system has significantly improved transfer power, system efficiency, and transfer distance due to continuous research and discussion worldwide. This review briefly presents the basic working principle of the CPT system and summarizes the theoretical research in four aspects, including coupling coupler and high-frequency power converter. Following this, the review focuses on research in six key directions, including system modelling and efficiency optimization. The application of CPT technology in five fields, including medical devices and transportation, is also discussed. This review introduces the progress of CPT research in recent years, hoping to serve as a reference for researchers, to promote the further research and application of the CPT system. Full article
(This article belongs to the Collection Wireless Power Transfer: Material, Technologies, and Applications)
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17 pages, 6358 KiB  
Article
Smart Cities and Awareness of Sustainable Communities Related to Demand Response Programs: Data Processing with First-Order and Hierarchical Confirmatory Factor Analyses
by Simona-Vasilica Oprea, Adela Bâra, Cristian-Eugen Ciurea and Laura Florentina Stoica
Electronics 2022, 11(7), 1157; https://doi.org/10.3390/electronics11071157 - 6 Apr 2022
Cited by 5 | Viewed by 2840
Abstract
The mentality of electricity consumers is one of the most important entities that must be addressed when dealing with issues in the operation of power systems. Consumers are used to being completely passive, but recently these things have changed as significant progress of [...] Read more.
The mentality of electricity consumers is one of the most important entities that must be addressed when dealing with issues in the operation of power systems. Consumers are used to being completely passive, but recently these things have changed as significant progress of Information and Communication Technologies (ICT) and Internet of Things (IoT) has gained momentum. In this paper, we propose a statistical measurement model using a covariance structure, specifically a first-order confirmatory factor analysis (CFA) using SAS CALIS procedure to identify the factors that could contribute to the change of attitude within energy communities. Furthermore, this research identifies latent constructs and indicates which observed variables load on or measure them. For the simulation, two complex data sets of questionnaires created by the Irish Commission for Energy Regulation (CER) were analyzed, demonstrating the influence of some exogenous variables on the items of the questionnaires. The results revealed that there is a relevant relationship between the social–economic and the behavioral factors and the observed variables. Furthermore, the models provided a good fit to the data, as measured by the performance indicators. Full article
(This article belongs to the Special Issue Advances in Machine Learning, IoT and Big Data for Sustainable Communities)
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14 pages, 5676 KiB  
Article
Design of a Low-Profile Wideband Magnetoelectric Dipole Antenna with Reduced Gain Drop
by Zhiyi Li, Xing Chen, Yuzhu Tang, Liangbing Liao, Linwan Deng and Zhifan Zhao
Electronics 2022, 11(7), 1156; https://doi.org/10.3390/electronics11071156 - 6 Apr 2022
Cited by 2 | Viewed by 2688
Abstract
In this paper, a novel low-profile magnetoelectric (ME) dipole antenna with wideband is presented. The conventional vertical fixing structure is bended four times from the center to the sides. The Γ-shaped feeding structure is bended two times to lower the height of the [...] Read more.
In this paper, a novel low-profile magnetoelectric (ME) dipole antenna with wideband is presented. The conventional vertical fixing structure is bended four times from the center to the sides. The Γ-shaped feeding structure is bended two times to lower the height of the antenna step by step. The effect of three kinds of vertical wall is discussed to show their influence on boresight gain. Through comparison, only one vertical wall is erected on the left side of the ground to decrease the boresight gain drop at 2.2 GHz. Both simulation and analysis are made to sufficiently explain the working principle. At last, the proposed ME dipole antenna has only 0.095λ0 (λ0 is the center operating wavelength in free space) in height, and the wideband property is still maintained. By simulation, the relative bandwidth for VSWR < 2.0 is 47.9% (from 1.35 to 2.2 GHz). The boresight gain ranges from 8.1 to 9.6 dBi in the operating band. The measured relative bandwidth for VSWR < 2.0 is 50.3% (from 1.34 to 2.24 GHz), and the boresight gain ranges from 7.38 to 8.73 dBi. The gain drop on boresight is less than 1.4 dBi. Radiation patterns show a unidirectional characteristic in the whole operating band. Additionally, the cross-polarization level is less than −25 dB on boresight. The simulating and measuring results agree well with each other. Therefore, the proposed antenna is suitable for applications of limited height and wideband. Full article
(This article belongs to the Topic Antennas)
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31 pages, 992 KiB  
Review
Communication Technologies in Emergency Situations
by Anna Carreras-Coch, Joan Navarro, Carles Sans and Agustín Zaballos
Electronics 2022, 11(7), 1155; https://doi.org/10.3390/electronics11071155 - 6 Apr 2022
Cited by 13 | Viewed by 8149
Abstract
Emergency situations such as wildfires, water floods, or even terrorist attacks require continuous communication between the coordination centres, the several on-the-field teams, and their respective devices to properly address the adverse circumstances. From a technological point of view, this can be best seen [...] Read more.
Emergency situations such as wildfires, water floods, or even terrorist attacks require continuous communication between the coordination centres, the several on-the-field teams, and their respective devices to properly address the adverse circumstances. From a technological point of view, this can be best seen as a live Ubiquitous Sensor Network—composed of human beings (e.g., first responders, victims) and devices (e.g., drones, environmental sensors, radios)—with stringent and special communication requirements in terms of flexibility, mobility, reliability, bandwidth, heterogeneity, and speed of deployment. However, for this specific use case, most of the already deployed and well-known communication technologies (e.g., satellite, 4G/5G) might become unusable and hard to repair due to the associated effects of the disaster itself. The purpose of this paper is (1) to review the emergency communications challenges, (2) to analyse the existing surveys on technologies for emergency situations, (3) to conduct a more updated, extensive, and systematic review of the emergency communications’ technologies, and (4) to propose a heterogeneous communication architecture able to communicate between moving agents in harsh conditions. The proposed approach is conceived to link the relocating agents that constitute a Ubiquitous Sensor Network spanning a large-scale area (i.e., hundreds of square kilometres) by combining Near Vertical Incidence Skywave technologies with Drone-Based Wireless Mesh Networks. The conclusions derived from this research aim to set up the fundamentals of a rapidly deployable Emergency Communications System inspired by the Ubiquitous Sensor Network paradigm. Full article
(This article belongs to the Special Issue Ubiquitous Sensor Networks)
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12 pages, 580 KiB  
Article
Integrated Equipment for Parkinson’s Disease Early Detection Using Graph Convolution Network
by Yefei He, Tao Yang, Cheng Yang and Hong Zhou
Electronics 2022, 11(7), 1154; https://doi.org/10.3390/electronics11071154 - 6 Apr 2022
Cited by 4 | Viewed by 3124
Abstract
There is an increasing need to diagnose Parkinson’s disease (PD) in an early stage. Existing solutions mainly focused on traditional ways such as MRI, thus suffering from the ease-of-use issue. This work presents a new approach using video and skeleton-based techniques to solve [...] Read more.
There is an increasing need to diagnose Parkinson’s disease (PD) in an early stage. Existing solutions mainly focused on traditional ways such as MRI, thus suffering from the ease-of-use issue. This work presents a new approach using video and skeleton-based techniques to solve this problem. In this paper, an end-to-end Parkinson’s disease early diagnosis method based on graph convolution networks is proposed, which takes patients’ skeletons sequence as input and returns the diagnosis result. The asymmetric dual-branch network architecture is designed to process global and local information separately and capture the subtle manifestation of PD. To train the network, we present the first Parkinson’s disease gait dataset, PD-Walk. This dataset consists of 95 PD patients and 96 healthy people’s walking videos. All the data are annotated by experienced doctors. Furthermore, we implement our method on portable equipment, which has been in operation in the First Affiliated Hospital, Zhejiang University School of Medicine. Experiments show that our method can achieve 84.1% accuracy and achieve real-time performance on the equipment in the real environment. Compared with traditional solutions, the proposed method can detect suspicious PD symptoms quickly and conveniently. Integrated equipment can be easily placed in hospitals or nursing homes to provide services for elderly people. Full article
(This article belongs to the Topic Applied System on Biomedical Engineering, Healthcare and Sustainability)
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17 pages, 1655 KiB  
Article
A Cascade Framework for Privacy-Preserving Point-of-Interest Recommender System
by Longyin Cui and Xiwei Wang
Electronics 2022, 11(7), 1153; https://doi.org/10.3390/electronics11071153 - 6 Apr 2022
Cited by 3 | Viewed by 2116
Abstract
Point-of-interest (POI) recommender systems (RSes) have gained significant popularity in recent years due to the prosperity of location-based social networks (LBSN). However, in the interest of personalization services, various sensitive contextual information is collected, causing potential privacy concerns. This paper proposes a cascaded [...] Read more.
Point-of-interest (POI) recommender systems (RSes) have gained significant popularity in recent years due to the prosperity of location-based social networks (LBSN). However, in the interest of personalization services, various sensitive contextual information is collected, causing potential privacy concerns. This paper proposes a cascaded privacy-preserving POI recommendation (CRS) framework that protects contextual information such as user comments and locations. We demonstrate a minimized trade-off between the privacy-preserving feature and prediction accuracy by applying a semi-decentralized model to real-world datasets. Full article
(This article belongs to the Special Issue Recommender Systems: Approaches, Challenges and Applications)
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17 pages, 751 KiB  
Article
M-Emu: A Platform for Multicast Emulation
by Zhenyu Tian, Jiali You and Hong Ni
Electronics 2022, 11(7), 1152; https://doi.org/10.3390/electronics11071152 - 6 Apr 2022
Viewed by 2048
Abstract
Network layer multicast research is an important field of network research that requires simulators or emulators to support Software-Defined Networking (SDN) as well as to provide a specific structure at the network layer to facilitate packet forwarding, such as a multicast tree. The [...] Read more.
Network layer multicast research is an important field of network research that requires simulators or emulators to support Software-Defined Networking (SDN) as well as to provide a specific structure at the network layer to facilitate packet forwarding, such as a multicast tree. The existing emulation platforms cannot effectively support the emulation of certain key multicast technologies, such as the Grafting Point (GP)-selection method and Rendezvous Point (RP)-selection method, for the following reasons: First, the programmable data plane of the existing emulation platform has many defects, such as the inability to process packet scheduling tasks, the prohibition of dynamic memory allocation and loops with unknown iteration counts, which make it difficult to deploy complex multicast protocols and algorithms. Secondly, at present, no emulation platform integrates network layer multicast emulation functions. As a result, users need to develop the multicast tree construction and maintenance mechanism in advance, which makes experiments laborious. To solve the above problems, based on NS4, we designed a multicast emulation platform, M-Emu. M-Emu presents a Service-Forwarding Architecture, which enables the data plane to deploy arbitrary complex protocols and algorithms. Based on the Service-Forwarding Architecture, M-Emu integrates a Multicast-Emulation Framework, which has a complete multicast tree construction and maintenance mechanism. We explain in detail how the various parts of M-Emu cooperate to complete the multicast emulation with an example and prove that M-Emu is efficient in CPU and memory consumption, etc., through a large number of experiments. Full article
(This article belongs to the Section Computer Science & Engineering)
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15 pages, 989 KiB  
Article
Human Detection in Aerial Thermal Images Using Faster R-CNN and SSD Algorithms
by K. R. Akshatha, A. Kotegar Karunakar, Satish B. Shenoy, Abhilash K. Pai, Nikhil Hunjanal Nagaraj and Sambhav Singh Rohatgi
Electronics 2022, 11(7), 1151; https://doi.org/10.3390/electronics11071151 - 6 Apr 2022
Cited by 34 | Viewed by 6607
Abstract
The automatic detection of humans in aerial thermal imagery plays a significant role in various real-time applications, such as surveillance, search and rescue and border monitoring. Small target size, low resolution, occlusion, pose, and scale variations are the significant challenges in aerial thermal [...] Read more.
The automatic detection of humans in aerial thermal imagery plays a significant role in various real-time applications, such as surveillance, search and rescue and border monitoring. Small target size, low resolution, occlusion, pose, and scale variations are the significant challenges in aerial thermal images that cause poor performance for various state-of-the-art object detection algorithms. Though many deep-learning-based object detection algorithms have shown impressive performance for generic object detection tasks, their ability to detect smaller objects in the aerial thermal images is analyzed through this study. This work carried out the performance evaluation of Faster R-CNN and single-shot multi-box detector (SSD) algorithms with different backbone networks to detect human targets in aerial view thermal images. For this purpose, two standard aerial thermal datasets having human objects of varying scale are considered with different backbone networks, such as ResNet50, Inception-v2, and MobileNet-v1. The evaluation results demonstrate that the Faster R-CNN model trained with the ResNet50 network architecture out-performed in terms of detection accuracy, with a mean average precision (mAP at 0.5 IoU) of 100% and 55.7% for the test data of the OSU thermal dataset and AAU PD T datasets, respectively. SSD with MobileNet-v1 achieved the highest detection speed of 44 frames per second (FPS) on the NVIDIA GeForce GTX 1080 GPU. Fine-tuning the anchor parameters of the Faster R-CNN ResNet50 and SSD Inception-v2 algorithms caused remarkable improvement in mAP by 10% and 3.5%, respectively, for the challenging AAU PD T dataset. The experimental results demonstrated the application of Faster R-CNN and SSD algorithms for human detection in aerial view thermal images, and the impact of varying backbone network and anchor parameters on the performance improvement of these algorithms. Full article
(This article belongs to the Special Issue Machine Learning and Photonics Cooperation: Principles, Algorithms, and Systems)
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15 pages, 1815 KiB  
Article
Secrecy Enhancement for SSK-Based Visible Light Communication Systems
by Wangzhaoqi Xie, Bao Li, Yuyang Peng, Han Zhu, Fawaz AL-Hazemi and Mohammad Meraj Mirza
Electronics 2022, 11(7), 1150; https://doi.org/10.3390/electronics11071150 - 6 Apr 2022
Cited by 2 | Viewed by 1982
Abstract
Visible light communication (VLC) is a technology that uses unlicensed light spectrum resources and high spatial reuse rates for communication. Because it does not occupy any resource allocation in wireless communication, it has fully alleviated the problem of spectrum scarcity in radio frequency [...] Read more.
Visible light communication (VLC) is a technology that uses unlicensed light spectrum resources and high spatial reuse rates for communication. Because it does not occupy any resource allocation in wireless communication, it has fully alleviated the problem of spectrum scarcity in radio frequency (RF) communication and gradually become a new development direction. However, owing to the inherent broadcasting nature of the VLC channel, the VLC link is vulnerable to eavesdropping by unexpected or unauthorized users in spacious public places. Therefore, enhancing the security of the VLC system has attracted extensive attention. This paper studies the security optimization scheme of the VLC system based on the space shift keying (SSK) technology in the free space optical environment called the SSK-VLC system. The antenna selection (AS) technology and artificial noise (AN) cancellation method are adopted to enhance the confidentiality of the SSK-VLC system. In this paper, we presume that the SSK-VLC system includes three parts: a transmitter containing multiple light-emitting diodes, a legitimate receiver, and an eavesdropper, respectively. By using the designed AS and AN method, the transmitted valid information can be demodulated at the legitimate receiver, and at the same time, the received information by the eavesdropper will be disturbed. The simulation results prove that the proposed optimization scheme can further improve the security performance, including the secrecy rate (SR) and the bit error ratio (BER), compared with the traditional SSK-VLC scheme. Full article
(This article belongs to the Special Issue MIMO: Multiple Input Multiple Output Technology for Physical-Layer Security)
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12 pages, 5375 KiB  
Article
A 1.2-µW 41-dB Ripple Attenuation Chopper Amplifier Using Auto-Zero Offset Cancelation Loop for Area-Efficient Biopotential Sensing
by Xuan Thanh Pham, Trung Kien Vu, Tien Dzung Nguyen and Loan Pham-Nguyen
Electronics 2022, 11(7), 1149; https://doi.org/10.3390/electronics11071149 - 6 Apr 2022
Cited by 10 | Viewed by 2922
Abstract
In this paper, a low-power and low-noise capacitive-coupled chopper instrumentation amplifier (CCIA) is proposed for biopotential sensing applications. A chopping technique is applied to mitigate the domination of flicker noise at low frequency. A new offset cancellation loop is also used to deal [...] Read more.
In this paper, a low-power and low-noise capacitive-coupled chopper instrumentation amplifier (CCIA) is proposed for biopotential sensing applications. A chopping technique is applied to mitigate the domination of flicker noise at low frequency. A new offset cancellation loop is also used to deal with the intrinsic offset, originating from process variation, to reduce ripple noise at the output of CCIA. Moreover, the optimization of the chip area was resolved by adding a T-network capacitor in the negative feedback loop. The CCIA is designed on 0.18 µm process CMOS technology with a total chip area of 0.09 mm2. The post-simulation results show that the proposed architecture can attenuate the output ripple up to 41 dB with a closed-loop gain of 40 dB and up to 800 Hz of bandwidth. The integrated input referred noise (IRN) of the CCIA is 1.8 µVrms over a bandwidth of 200 Hz. A noise efficiency factor (NEF) of 5.4 is obtained with a total power dissipation of 1.2 µW and a supply voltage of 1 V, corresponding to a power efficiency factor of 9.7 that is comparable with that of state-of-the-art studies. Full article
(This article belongs to the Special Issue Ultra-Low Voltage CMOS Front-End Design)
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15 pages, 5306 KiB  
Article
Accelerated Diagnosis of Novel Coronavirus (COVID-19)—Computer Vision with Convolutional Neural Networks (CNNs)
by Arfan Ghani, Akinyemi Aina, Chan Hwang See, Hongnian Yu and Simeon Keates
Electronics 2022, 11(7), 1148; https://doi.org/10.3390/electronics11071148 - 6 Apr 2022
Cited by 12 | Viewed by 2544
Abstract
Early detection and diagnosis of COVID-19, as well as the exact separation of non-COVID-19 cases in a non-invasive manner in the earliest stages of the disease, are critical concerns in the current COVID-19 pandemic. Convolutional Neural Network (CNN) based models offer a remarkable [...] Read more.
Early detection and diagnosis of COVID-19, as well as the exact separation of non-COVID-19 cases in a non-invasive manner in the earliest stages of the disease, are critical concerns in the current COVID-19 pandemic. Convolutional Neural Network (CNN) based models offer a remarkable capacity for providing an accurate and efficient system for the detection and diagnosis of COVID-19. Due to the limited availability of RT-PCR (Reverse transcription-polymerase Chain Reaction) tests in developing countries, imaging-based techniques could offer an alternative and affordable solution to detect COVID-19 symptoms. This paper reviewed the current CNN-based approaches and investigated a custom-designed CNN method to detect COVID-19 symptoms from CT (Computed Tomography) chest scan images. This study demonstrated an integrated method to accelerate the process of classifying CT scan images. In order to improve the computational time, a hardware-based acceleration method was investigated and implemented on a reconfigurable platform (FPGA). Experimental results highlight the difference between various approximations of the design, providing a range of design options corresponding to both software and hardware. The FPGA-based implementation involved a reduced pre-processed feature vector for the classification task, which is a unique advantage of this particular application. To demonstrate the applicability of the proposed method, results from the CPU-based classification and the FPGA were measured separately and compared retrospectively. Full article
(This article belongs to the Collection Deep Learning for Computer Vision: Algorithms, Theory and Application)
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15 pages, 4843 KiB  
Article
A Real-Coding Population-Based Incremental Learning Evolutionary Algorithm for Multi-Satellite Scheduling
by Yuqing Li, Xiaoen Feng, Gang Wang, Dong Yan, Pengpeng Liu and Chao Zhang
Electronics 2022, 11(7), 1147; https://doi.org/10.3390/electronics11071147 - 6 Apr 2022
Cited by 7 | Viewed by 1808
Abstract
With the increasing demand for earth observation in various fields, remote satellites play an important role in ground information assurance. Apparently, the effective scheduling and utilization of multi-satellite resources determine the quality and efficiency of information acquisition. In this paper, focusing on the [...] Read more.
With the increasing demand for earth observation in various fields, remote satellites play an important role in ground information assurance. Apparently, the effective scheduling and utilization of multi-satellite resources determine the quality and efficiency of information acquisition. In this paper, focusing on the problem of centralized multi-satellite scheduling, we establish a mathematical model of satellite scheduling with complex constraints of load and platform operation. We also propose a real-coding Population Incremental Based Learning (PBIL) algorithm to solve the multi-satellite scheduling problem. The real-coding format can greatly shorten the coding length compared to the traditional PBIL algorithm with binary coding so that the computational efficiency is improved. Additionally, we design a value probability matrix, correction coefficient and mutation operator to guide better evolution and avoid early convergence. Finally, we take some numerical examples to verify the real-coding PBIL algorithm for multi-satellite scheduling. The performance of the algorithm is analyzed by comparing it with binary-coding PBIL and the Genetic Algorithm (GA). Additionally, the influence of key parameters on algorithm performance, such as probability correction coefficient, is also analyzed. Full article
(This article belongs to the Section Computer Science & Engineering)
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17 pages, 2024 KiB  
Article
A Hybrid Deep Learning-Based Approach for Brain Tumor Classification
by Asaf Raza, Huma Ayub, Javed Ali Khan, Ijaz Ahmad, Ahmed S. Salama, Yousef Ibrahim Daradkeh, Danish Javeed, Ateeq Ur Rehman and Habib Hamam
Electronics 2022, 11(7), 1146; https://doi.org/10.3390/electronics11071146 - 5 Apr 2022
Cited by 146 | Viewed by 10185
Abstract
Brain tumors (BTs) are spreading very rapidly across the world. Every year, thousands of people die due to deadly brain tumors. Therefore, accurate detection and classification are essential in the treatment of brain tumors. Numerous research techniques have been introduced for BT detection [...] Read more.
Brain tumors (BTs) are spreading very rapidly across the world. Every year, thousands of people die due to deadly brain tumors. Therefore, accurate detection and classification are essential in the treatment of brain tumors. Numerous research techniques have been introduced for BT detection as well as classification based on traditional machine learning (ML) and deep learning (DL). The traditional ML classifiers require hand-crafted features, which is very time-consuming. On the contrary, DL is very robust in feature extraction and has recently been widely used for classification and detection purposes. Therefore, in this work, we propose a hybrid deep learning model called DeepTumorNet for three types of brain tumors (BTs)—glioma, meningioma, and pituitary tumor classification—by adopting a basic convolutional neural network (CNN) architecture. The GoogLeNet architecture of the CNN model was used as a base. While developing the hybrid DeepTumorNet approach, the last 5 layers of GoogLeNet were removed, and 15 new layers were added instead of these 5 layers. Furthermore, we also utilized a leaky ReLU activation function in the feature map to increase the expressiveness of the model. The proposed model was tested on a publicly available research dataset for evaluation purposes, and it obtained 99.67% accuracy, 99.6% precision, 100% recall, and a 99.66% F1-score. The proposed methodology obtained the highest accuracy compared with the state-of-the-art classification results obtained with Alex net, Resnet50, darknet53, Shufflenet, GoogLeNet, SqueezeNet, ResNet101, Exception Net, and MobileNetv2. The proposed model showed its superiority over the existing models for BT classification from the MRI images. Full article
(This article belongs to the Special Issue Intelligent Data Sensing, Processing, Mining, and Communication)
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14 pages, 812 KiB  
Article
ASMAC: An Adaptive Slot Access MAC Protocol in Distributed VANET
by Shi-Yuan Han and Chang-Yue Zhang
Electronics 2022, 11(7), 1145; https://doi.org/10.3390/electronics11071145 - 5 Apr 2022
Cited by 5 | Viewed by 2816
Abstract
The media access control (MAC) protocol is responsible for channel resource sharing and conflict management in the communication process in VANET, which is of great significance for ensuring efficient and reliable communication. The existing MAC protocol with fixed time slot allocation cannot solve [...] Read more.
The media access control (MAC) protocol is responsible for channel resource sharing and conflict management in the communication process in VANET, which is of great significance for ensuring efficient and reliable communication. The existing MAC protocol with fixed time slot allocation cannot solve the problem of time slot resource exhaustion or waste when the traffic density is unbalanced. In this paper, we propose an adaptive time slot access MAC protocol in distributed VANET (ASMAC). ASMAC adapts the access time slot according to the driving direction of the vehicle and the traffic density ratio to improve the time slot access efficiency. In the ASMAC protocol, the frame is divided into several time slots based on TDMA, and the time slots in a frame are divided into two time slot sets according to the driving direction. The vehicle selects a time slot access corresponding to the time slot set. When the vehicle finds that there is no accessible time slot in the time slot set, it accesses the available time slot in the reverse time slot set to improve the efficiency of time slot access. In this paper, the analysis and simulation results of highway and four-way intersection scenarios are given and the validity of the ASMAC protocol is verified by comparing with the VeMAC and SAMD protocols. Full article
(This article belongs to the Special Issue Network Protocols for Wireless Sensor Networks)
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22 pages, 12748 KiB  
Article
Methods to Improve Dynamic System Response of Power Compensators Using Supercapacitors in Low-Voltage Ride-Through (LVRT) Conditions
by Mi-na Kim, Jun-sin Yi, Chung-Yuen Won and Jung-Hyo Lee
Electronics 2022, 11(7), 1144; https://doi.org/10.3390/electronics11071144 - 5 Apr 2022
Cited by 2 | Viewed by 2077
Abstract
In this paper, a power compensator using supercapacitors in parallel to protect grid-connected devices connected to the distributed power supply in the case of a low-voltage ride-through (LVRT) situation in designed, and a grid-connected device control method with improved responsiveness is proposed. In [...] Read more.
In this paper, a power compensator using supercapacitors in parallel to protect grid-connected devices connected to the distributed power supply in the case of a low-voltage ride-through (LVRT) situation in designed, and a grid-connected device control method with improved responsiveness is proposed. In the LVRT situation, the distributed generation power may boost the DC_link voltage, increasing the risk of destroying grid-connected devices. To prevent this, the power compensator designed in this study absorbs active power in a fault situation and stores it in the supercapacitor to suppress the DC_link voltage rise and efficiently use the power. In addition, we propose methods to improve the response of the grid reactive power through the reactive power compensation of the power compensator in LVRT situation. To this end, the power angle (θPW) was extracted through the formula, and the reactive power command, to be compensated by the power compensator, and the reactive power command, compensated by the grid-connected devices, were calculated according to the active power value. In this way, the grid power controlled by the power compensation device and the grid-connected devices was controlled by the active/reactive power of the same power angle and analyzed mathematically. Active power control and static grid support were performed in the normal state where the reduction rate of the normal value of the grid voltage was around 10%. However, when the grid voltage dropped by 10% to 100%, the reactive power control was appropriately performed with dynamic grid support by increasing the voltage from 10% to 20% or more. We conducted a simulation of the new and renewable energy grid-connected devices using the OPAL-RT-based Hardware-in-the Loop Simulation (HILS) system to control the proposed active/reactive power. Full article
(This article belongs to the Section Power Electronics)
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17 pages, 1011 KiB  
Article
OntoDomus: A Semantic Model for Ambient Assisted Living System Based on Smart Homes
by Hubert Kenfack Ngankam, Hélène Pigot and Sylvain Giroux
Electronics 2022, 11(7), 1143; https://doi.org/10.3390/electronics11071143 - 5 Apr 2022
Cited by 13 | Viewed by 2977
Abstract
Ambient assisted living (AAL) makes it possible to build assistance for older adults according to the person’s context. Understanding the person’s context sometimes involves transforming one’s home into a smart home. Typically, this is carried out using nonintrusively distributed sensors and calm technologies. [...] Read more.
Ambient assisted living (AAL) makes it possible to build assistance for older adults according to the person’s context. Understanding the person’s context sometimes involves transforming one’s home into a smart home. Typically, this is carried out using nonintrusively distributed sensors and calm technologies. Older adults often have difficulty performing activities of daily living, such as taking medication, drinking coffee, watching television, using certain electronic devices, and dressing. This difficulty is even greater when these older adults suffer from cognitive impairments. Defining an assistance solution requires a multidisciplinary and iterative collaborative approach. It is necessary, therefore, to reason about the imperatives and solutions of this multidisciplinary collaboration (e.g., clinical), as well as the adaptation of technical constraints (e.g., technologies). A common approach to reasoning is to represent knowledge using logic-based formalisms, such as ontologies. However, there is not yet an established ontology that defines concepts such as multidisciplinary collaboration in successive stages of the assistance process. This article presents OntoDomus, an ontology that describes, at several levels, the semantic interactions between ambient assisted living, context awareness, smart home, and Internet of Things, based on multidisciplinarity. It revolves around two main notions: multidisciplinarity, based on specific sub-ontologies and the ambient feedback loop. OntoDomus combines SPARQL queries and OWL 2 models to improve the reusability of domain terminology, allowing stakeholders to represent their knowledge in different collaborative and adaptive situations. The ontological model is validated, first by its reuse in more specific works—specific to an aspect of ambient assistance. Second, it is validated by the structuring of ambient knowledge and inferences of the formalization in a case study that includes instances for a particular activity of daily living. It places the ambient feedback loop at the center of the ontology by focusing on highly expressive domain ontology formalisms with a low level of expressiveness between them. Full article
(This article belongs to the Special Issue Intelligent Surveillance and Smart Home)
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15 pages, 4417 KiB  
Article
An End-to-End Video Steganography Network Based on a Coding Unit Mask
by Huanhuan Chai, Zhaohong Li, Fan Li and Zhenzhen Zhang
Electronics 2022, 11(7), 1142; https://doi.org/10.3390/electronics11071142 - 5 Apr 2022
Cited by 10 | Viewed by 3100
Abstract
Steganography hides secret messages inside the covers while ensuring imperceptibility. Different from traditional steganography, deep learning-based steganography has an adaptable and generalized framework without needing expertise regarding the embedding process. However, most steganography algorithms utilize images as covers instead of videos, which are [...] Read more.
Steganography hides secret messages inside the covers while ensuring imperceptibility. Different from traditional steganography, deep learning-based steganography has an adaptable and generalized framework without needing expertise regarding the embedding process. However, most steganography algorithms utilize images as covers instead of videos, which are more expressive and more widely spread. To this end, an end-to-end deep learning network for video steganography is proposed in this paper. A multiscale down-sampling feature extraction structure is designed, which consists of three parts including an encoder, a decoder, and a discriminator network. Furthermore, in order to facilitate the learning ability of network, a CU (coding unit) mask built from a VVC (versatile video coding) video is first introduced. In addition, an attention mechanism is used to further promote the visual quality. The experimental results show that the proposed steganography network can achieve a better performance in terms of the perceptual quality of stego videos, decoding the accuracy of hidden messages, and the relatively high embedding capacity compared with the state-of-the-art steganography networks. Full article
(This article belongs to the Special Issue Digital and Optical Security Algorithms via Machine Learning)
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12 pages, 785 KiB  
Article
An Efficient Simulation-Based Policy Improvement with Optimal Computing Budget Allocation Based on Accumulated Samples
by Xilang Huang and Seon Han Choi
Electronics 2022, 11(7), 1141; https://doi.org/10.3390/electronics11071141 - 4 Apr 2022
Cited by 1 | Viewed by 1830
Abstract
Markov decision processes (MDPs) are widely used to model stochastic systems to deduce optimal decision-making policies. As the transition probabilities are usually unknown in MDPs, simulation-based policy improvement (SBPI) using a base policy to derive optimal policies when the state transition probabilities are [...] Read more.
Markov decision processes (MDPs) are widely used to model stochastic systems to deduce optimal decision-making policies. As the transition probabilities are usually unknown in MDPs, simulation-based policy improvement (SBPI) using a base policy to derive optimal policies when the state transition probabilities are unknown is suggested. However, estimating the Q-value of each action to determine the best action in each state requires many simulations, which results in efficiency problems for SBPI. In this study, we propose a method to improve the overall efficiency of SBPI using optimal computing budget allocation (OCBA) based on accumulated samples. Previous works have mainly focused on improving SBPI efficiency for a single state and without using the previous simulation samples. In contrast, the proposed method improves the overall efficiency until an optimal policy can be found in consideration of the state traversal property of the SBPI. The proposed method accumulates simulation samples across states to estimate the unknown transition probabilities. These probabilities are then used to estimate the mean and variance of the Q-value for each action, which allows the OCBA to allocate the simulation budget efficiently to find the best action in each state. As the SBPI traverses the state, the accumulated samples allow appropriate allocation of OCBA; thus, the optimal policy can be obtained with a lower budget. The experimental results demonstrate the improved efficiency of the proposed method compared to previous works. Full article
(This article belongs to the Special Issue Advances in Stochastic System Modeling, Control, Optimization, and Their Applications)
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15 pages, 3506 KiB  
Article
Analysis of LED Lamps’ Sensitivity to Surge Impulse
by Wiesław Sabat, Dariusz Klepacki, Kazimierz Kamuda and Kazimierz Kuryło
Electronics 2022, 11(7), 1140; https://doi.org/10.3390/electronics11071140 - 4 Apr 2022
Cited by 3 | Viewed by 2272
Abstract
The results of research on the influence of the 1.2/50 µs (8/20 µs) surge impulse on the reliability of commercial LED lamps are presented in the paper. For two types of lamps, differing in the declared warranty period, tests were carried out in [...] Read more.
The results of research on the influence of the 1.2/50 µs (8/20 µs) surge impulse on the reliability of commercial LED lamps are presented in the paper. For two types of lamps, differing in the declared warranty period, tests were carried out in which it was determined how the impulse of 1.2/50 µs (8/20 µs) is propagated in their supply systems. During the tests, the effects it causes on the critical levels and how its level influences the probability of failure of the tested lamp were examined. These solutions are currently being used in mass production of LED lamps and are characteristic of budget devices. Sensitivity tests were conducted for a group of 150 lamps divided evenly into 10 batches. The tests were carried out in accordance with the standards of EN 61000-4-5: 2014 and EN 61547: 2009 with one exception: the impulse level was not limited to the 0.5 kV recommended in EN 61547: 2009 for this class of components, but increased to a value that leads to permanent damage. These tests allowed us to determine the margin from the value specified in the standard to the sensitivity of the tested lamps on this type of disturbance. Full article
(This article belongs to the Section Microelectronics)
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14 pages, 4298 KiB  
Article
Fast Readout of Split-Ring Resonators Made Simple and Low-Cost for Application in HPLC
by Moritz Hitzemann, Kirsten J. Dehning, Adrian V. Gehl, Erk-Fietje Sterr and Stefan Zimmermann
Electronics 2022, 11(7), 1139; https://doi.org/10.3390/electronics11071139 - 4 Apr 2022
Cited by 4 | Viewed by 2462
Abstract
Split-ring resonators (SRR) are simple electrical circuits that show a significant shift in resonance frequency even with the smallest changes in split capacitance, and thus in permittivity, electric conductivity, and dielectric losses of the split capacitor’s dielectric. Usually, the resonance frequency is derived [...] Read more.
Split-ring resonators (SRR) are simple electrical circuits that show a significant shift in resonance frequency even with the smallest changes in split capacitance, and thus in permittivity, electric conductivity, and dielectric losses of the split capacitor’s dielectric. Usually, the resonance frequency is derived from the frequency response, but recording the frequency spectrum takes a certain amount of time. Here, we present a new capillary split-ring resonator CaSRR with fast readout for liquid chromatography (LC), which is capable of accurately detecting very fast changes in split capacity. The proposed method is based on the detection of the transmitted signal at a single frequency that is analyzed by demodulation. The demodulated signal changes its amplitude depending on the shift of the resonance frequency. Our simple low-cost electronics enables an average sampling rate of 42 Hz with 128 averages of the demodulated signal and has a frequency stability of 840 mHz. Thus, a minimum change in permittivity of Δεr,min = 11.26 × 10−3 can be detected. Finally, a chromatogram of one sugar (glucose) and one sugar alcohol (xylitol) is recorded using the SRR and is compared to a standard refractive index detector. Full article
(This article belongs to the Section Industrial Electronics)
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22 pages, 1232 KiB  
Article
Efficient FPGA Implementation of an ANN-Based Demapper Using Cross-Layer Analysis
by Jonas Ney, Bilal Hammoud, Sebastian Dörner, Matthias Herrmann, Jannis Clausius, Stephan ten Brink and Norbert Wehn
Electronics 2022, 11(7), 1138; https://doi.org/10.3390/electronics11071138 - 3 Apr 2022
Cited by 4 | Viewed by 2733
Abstract
In the field of communication, autoencoder (AE) refers to a system that replaces parts of the traditional transmitter and receiver with artificial neural networks (ANNs). To meet the system performance requirements, it is necessary for the AE to adapt to the changing wireless-channel [...] Read more.
In the field of communication, autoencoder (AE) refers to a system that replaces parts of the traditional transmitter and receiver with artificial neural networks (ANNs). To meet the system performance requirements, it is necessary for the AE to adapt to the changing wireless-channel conditions at runtime. Thus, online fine-tuning in the form of ANN-retraining is of great importance. Many algorithms on the ANN layer are developed to improve the AE’s performance at the communication layer. Yet, the link of the system performance and the ANN topology to the hardware layer is not fully explored. In this paper, we analyze the relations between the design layers and present a hardware implementation of an AE-based demapper that enables fine-tuning to adapt to varying channel conditions. As a platform, we selected field-programmable gate arrays (FPGAs) which provide high flexibility and allow to satisfy the low-power and low-latency requirements of embedded communication systems. Furthermore, our cross-layer approach leverages the flexibility of FPGAs to dynamically adapt the degree of parallelism (DOP) to satisfy the system-level requirements and to ensure environmental adaptation. Our solution achieves 2000× higher throughput than a high-performance graphics processor unit (GPU), draws 5× less power than an embedded central processing unit (CPU) and is 5800× more energy efficient compared to an embedded GPU for small batch size. To the best of our knowledge, such a cross-layer design approach combined with FPGA implementation is unprecedented. Full article
(This article belongs to the Special Issue Applications of FPGAs and Reconfigurable Computing: Current Trends and Future Perspectives)
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15 pages, 7687 KiB  
Article
Gain Function-Based Visual Tracking Control for Inertial Stabilized Platform with Output Constraints and Disturbances
by Xiangyang Liu, Jun Yang and Pengyu Qiao
Electronics 2022, 11(7), 1137; https://doi.org/10.3390/electronics11071137 - 2 Apr 2022
Cited by 4 | Viewed by 1897
Abstract
In this paper, a composite control strategy is proposed to deal with output constraints and disturbances of the visual tracking system for an inertial stabilized platform, which combines active disturbance compensation and the variable gain function technique. Firstly, the model of system considering [...] Read more.
In this paper, a composite control strategy is proposed to deal with output constraints and disturbances of the visual tracking system for an inertial stabilized platform, which combines active disturbance compensation and the variable gain function technique. Firstly, the model of system considering multi-source disturbances is established, where the controlled output is the constrained position of the target in the image plane. Secondly, in order to avoid the tracked target being lost in the field of view of the camera, a control method based on the variable gain function technique is designed to ensure that the controlled output remains within the feasible range. Moreover, the active disturbance estimation and compensation method is introduced to improve the anti-disturbance ability of the system under the situation of small output error, obtaining satisfactory tracking performance. The stability analysis and the proof of constrained output are given following the controller design. Finally, results of simulation and experiments are shown to illustrate the promised advantages of the proposed composite control approach. Full article
(This article belongs to the Section Systems & Control Engineering)
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16 pages, 5517 KiB  
Article
An Efficient Object Navigation Strategy for Mobile Robots Based on Semantic Information
by Yu Guo, Yuanyan Xie, Yue Chen, Xiaojuan Ban, Balqies Sadoun and Mohammad S. Obaidat
Electronics 2022, 11(7), 1136; https://doi.org/10.3390/electronics11071136 - 2 Apr 2022
Cited by 6 | Viewed by 2942
Abstract
In recent years, the rapid development of computer vision makes it possible for mobile robots to be more intelligent. Among the related technologies, the visual SLAM system allows the mobile robot to locate itself, build the map, and provide a navigation strategy to [...] Read more.
In recent years, the rapid development of computer vision makes it possible for mobile robots to be more intelligent. Among the related technologies, the visual SLAM system allows the mobile robot to locate itself, build the map, and provide a navigation strategy to execute follow-up tasks, such as searching for objects in unknown environment according to the observed information. However, most of the existing studies are meant to provide a predefined trajectory for the robot or allow the robot to explore blindly and randomly, which undoubtedly affects the efficiency of the object navigation process and goes against with the idea of “intelligent”. To solve the above problems, an efficient object navigation strategy is proposed in this paper. Firstly, a semantic association model is obtained by using the Mask R-CNN and skip-gram to conduct correlation analysis of common indoor objects. Then, with the help of the above model and ROS framework, an effective object navigation strategy is designed to enable the robot to find the given target efficiently. Finally, the classical ORB-SLAM2 system method is integrated to help the robot build a high usability environment map and find passable paths when moving. Simulation results validated that the proposed strategy can efficiently help the robot to navigate to the object without human intervention. Full article
(This article belongs to the Special Issue Path Planning for Mobile Robots)
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