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Energy-based Directional Pilot Protection for Distribution Networks with IBDGs Considering Unmeasured Load Switching

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CSEE Journal of Power and Energy systems 2024年第1期10卷 139-150页

作者： Chenghan Zhou Guibin Zou Shuo Zhang Xuhui Wen key laboratory of Power system intelligent Dispatch and Control of Ministry of Education Shandong UniversityJinan 250061China

Inverter-based distributed generations(IBDGs)are the main approach to utilizing clean energy in distribution networks(DNs).Compared with synchronous source,fault response of IBDG is very different.As a result,in DNs with high penetration of IBDGs,legacy protection schemes will no longer be applicable.In this paper,an energy-based directional pilot protection scheme suitabie for DNs with IBDGs is proposed.This scheme considers the large range of phase angle caused by IBDG integration and uses improved energy polarity criterion to determine fault direction.In addition,magnitude of energy is used to distinguish between faults and load switching to overcome maloperation of directional pilot protection caused by internal unmeasured load switching.The proposed scheme first uses local measured information to determine fault direction sign and then exchanges the direction sign with the remote terminal.This scheme does not require high-bandwidth communication and strict data synchronization,so it can be implemented at a low cost.Finally,simulation studies verify effectiveness of the proposed scheme.

关键词： Distribution network energy polarity inverterbased distributed generation pilot protection unmeasured load

A hybrid attention model based on first-order statistical features for smoke recognition

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Science China(Technological Sciences) 2024年第3期67卷 809-822页

作者： GUO Nan LIU JiaHui DI KeXin GU Ke QIAO JunFei Beijing laboratory of Smart Environmental Protection Beijing Key Laboratory of Computational Intelligence and Intelligent SystemBeijing Artificial Intelligence InstituteBeijing 100124China Faculty of Information technology Beijing University of TechnologyBeijing 100124China

Smoke and fire recognition are of great importance on foreseeing fire disasters and preventing environmental pollution by monitoring the burning process of objects(e.g., straw, fuels). However, since fire images suffer from problems like the variability of the features, complexity of scenarios, interference from background, changeable weather conditions as well as image quality problems, identifying smoke and fire accurately and promptly from a given image still remains a substantial challenge. Automatically learning the features of smoke images by CNNs has improved the target recognition ability compared to traditional approaches,nonetheless, convolutions and pooling operations in CNNs may cause severe information loss which may lead to misjudgment.To tackle the above problems, this paper proposed a hybrid attention model based on the characteristics of smoke images. This model adopted multiple optimized attention mechanism in several stages to quickly and precisely capture the important features,achieving state-of-the-art performance on smoke and fire recognition in terms of accuracy and speed. Our proposed module mainly consists of two stages: pooling and attention. In the first stage, we conducted several newly proposed first-order pooling methods. Through traversing the data space in a larger scope, features are better reserved, thus constructing a more intact feature space of smoke and fire in an image. In the second stage, feature maps are aggregated together to perform channel and spatial attention. The channel and spatial dependencies allow us to quickly catch the important features presented in an image. By fully exploring the feature space and prominent salient features, characteristics of smoke and fire are better presented so as to obtain better smoke and fire detection results. Experiments have been conducted on public smoke detection dataset and new proposed fine-grained smoke and fire detection database. Experimental results revealed that the proposed method outperformed popular deep CNNs and exis

关键词： hybrid attention first-order pooling smoke and fire detection deep convolutional neural networks

Review on the terahertz metasensor:from featureless refractive index sensing to molecular identification

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Photonics Research 2024年第2期12卷 194-217页

作者： JIAMING LYU LIHAO HUANG LIN CHEN YIMING ZHU SONGLIN ZHUANG THz technology Innovation Research Institute Shanghai Key Laboratory of Modern Optical SystemUniversity of Shanghai for Science and TechnologyShanghai 200093China Shanghai Institute of intelligent Science and technology Tongji UniversityShanghai 200092China

The terahertz(THz)wave is at the intersection between photonics and electronics in the electromagnetic spectrum.Since the vibration mode of many biomedical molecules and the weak interaction mode inside the molecules fall in the THz regime,utilizing THz radiation as a signal source to operate substance information sensing has its unique advantages.Recently,the metamaterial sensor(metasensor)has greatly enhanced the interaction between signal and substances and spectral selectivity on the subwavelength scale.However,most past review articles have demonstrated the THz metasensor in terms of their structures,applications,or materials.Until recently,with the rapid development of metasensing technologies,the molecular information has paid much more attention to the platform of THz metasensors.In this review,we comprehensively introduce the THz metasensor for detecting not only the featureless refractive index but also the vibrational/chiral molecular information of analytes.The objectives of this review are to improve metasensing specificity either by chemical material-assisted analyte capture or by physical molecular information.Later,to boost THz absorption features in a certain frequency,the resonant responses of metasensors can be tuned to the molecular vibrational modes of target molecules,while frequency multiplexing techniques are reviewed to enhance broadband THz spectroscopic fingerprints.The chiral metasensors are also summarized to specific identification chiral molecules.Finally,the potential prospects of next generation THz metasensors are discussed.Compared to featureless refractive index metasensing,the specific metasensor platforms accelerated by material modification and molecular information will lead to greater impact in the advancement of trace detection of conformational dynamics of biomolecules in practical applications.

关键词： refractive index sensor

Indefinite metacavities coupled to a mirror:bound states in the continuum with anomalous resonance scaling

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Photonics Research 2024年第3期12卷 598-607页

作者： QIANG ZHANG PEIXIANG LI ZHIYUAN GU SHAODING LIU ZEJUN DUAN College of Electronic Information and Optical Engineering Taiyuan University of TechnologyTaiyuan 030024China key laboratory of Advanced Transducers and intelligent Control system Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China

Indefinite metacavities(IMCs)made of hyperbolic metamaterials show great advantages in terms of extremely small mode volume due to large wave vectors endowed by the unique hyperbolic dispersion.However,quality(Q)factors of IMCs are limited by Ohmic loss of metals and radiative loss of leaked waves.Despite the fact that Ohmic loss of metals is inevitable in IMCs,the radiative loss can be further suppressed by leakage engineering.Here we propose a mirror coupled IMC structure which is able to operate at Fabry–Pérot bound states in the continuum(BICs)while the hyperbolic nature of IMCs is retained.At the BIC point,the radiative loss of magnetic dipolar cavity modes in IMCs is completely absent,resulting in a considerably increased Q factor(>90).Deviating from the BIC point,perfect absorption bands(>0.99)along with a strong near-field intensity enhancement(>1.8×10^(4))appear when the condition of critical coupling is almost fulfilled.The proposed BICs are robust to the geometry and material composition of IMCs and anomalous scaling law of resonance is verified during the tuning of optical responses.We also demonstrate that the Purcell effect of the structure can be significantly improved under BIC and quasi-BIC regimes due to the further enhanced Q factor to mode volume ratio.Our results provide a new train of thought to design ultra-small optical nanocavities that may find many applications benefitting from strong light–matter interactions.

关键词： hyperbolic mirror definite

Ethical Decision-Making Framework Based on Incremental ILP Considering Conflicts

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Computers, Materials & Continua 2024年第3期78卷 3619-3643页

作者： Xuemin Wang Qiaochen Li Xuguang Bao guangxi key laboratory of Trusted Software Guilin University of Electronic TechnologyGuilin541004China

Humans are experiencing the inclusion of artificial agents in their lives,such as unmanned vehicles,service robots,voice assistants,and intelligent medical care.If the artificial agents cannot align with social values or make ethical decisions,they may not meet the expectations of humans.Traditionally,an ethical decision-making framework is constructed by rule-based or statistical approaches.In this paper,we propose an ethical decision-making framework based on incremental ILP(Inductive Logic Programming),which can overcome the brittleness of rule-based approaches and little interpretability of statistical approaches.As the current incremental ILP makes it difficult to solve conflicts,we propose a novel ethical decision-making framework considering conflicts in this paper,which adopts our proposed incremental ILP system.The framework consists of two processes:the learning process and the deduction process.The first process records bottom clauses with their score functions and learns rules guided by the entailment and the score function.The second process obtains an ethical decision based on the rules.In an ethical scenario about chatbots for teenagers’mental health,we verify that our framework can learn ethical rules and make ethical decisions.Besides,we extract incremental ILP from the framework and compare it with the state-of-the-art ILP systems based on ASP(Answer Set Programming)focusing on conflict resolution.The results of comparisons show that our proposed system can generate better-quality rules than most other systems.

关键词： Ethical decision-making inductive logic programming incremental learning conflicts

A guidance and control design with reduced information for a dual-spin stabilized projectile

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Defence technology（防务技术） 2024年第3期33卷 494-505页

作者： Yu Wang Jiyan Yu Xiaoming Wang Jia Fangxiu intelligent Ammunition technology National Defense key Discipline laboratory Nanjing University of Science and TechnologyNanjingJiangsu210094China

In this paper,an integrated guidance and control method based on an adaptive path-following controller is proposed to control a spin-stabilized projectile with only translational motion information under the constraint of an actuator,uncertainties in aerodynamic parameters and measurements,and control system complexity.Owing to the fairly high rotation speed,the dynamic model of this missile is strongly nonlinear,uncertain and coupled in pitch,yaw and roll channels.A theoretical equivalent resultant force and uncertainty compensation method are comprehensively used to realize decoupling of pitch and yaw.In response to the strong nonlinear and time-varying characteristics of the dynamic system,the quasi-linear model whose parameters are obtained by interpolation of points selected as the segmentation points in the trajectory envelope,is used for calculation in each step.To cope with the system uncertainty caused by model approximation,parameter uncertainty and ballistic interference,an extended state estimator is used to compensate the output feedback according to the test ballistic angle.In order to improve the tracking efficiency and ensure the tracking error convergence with only translational motion information,the virtual guide point,whose derivative is deduced according to the Lyapunov principle,is calculated in real time according to the projection relationship between the real-time position and the reference trajectory,and a virtual line-of-sight angle and the backstepping method are used for the design of the guidance and control system.In order to avoid the influence of control input saturation on the guidance and control performance due to the actuator limitation and improve the robustness of the system,an anti-saturation compensator is designed according to the two-step method.The feasibility and effectiveness of the path-following controller is verified through closed-loop flight simulations with measurement,control,and condition uncertainties.The results indicate that the designed controller can conv

关键词： Spin-stabilized projectile Reduced information Path-following control Extended state observer Coupled nonlinear system Input saturation

A Survey on Distributed Network Localization from a Graph Laplacian Perspective

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Journal of systems Science & Complexity 2024年第1期37卷 273-293页

作者： HAN Zhimin LIN Zhiyun FU Minyue Artificial Intelligence Institute School of AutomationHangzhou Dianzi UniversityHangzhou 310018China Shenzhen key laboratory of Control Theory and intelligent systems School of System Design and Intelligent ManufacturingSouthern University of Science and TechnologyShenzhen 518055China Peng Cheng laboratory Shenzhen 518000China

Network localization serves as a fundamental component for enabling various position based operations in multi-agent systems,facilitating tasks like target searching and formation control by providing accurate position information for all nodes in the network.Network localization focuses on the challenge of determining the positions of nodes within a network,relying on the known positions of anchor nodes and internode relative measurements.Over the past few decades,distributed network localization has garnered significant attention from researchers.This paper aims to provide a review of main results and advancements in the field of distributed network localization,with a particular focus on the perspective of graph Laplacian.Owning to its favorable characteristics,graph Laplacian unifies various network localization,even when dealing with diverse types of internode relative measurements,into a unified protocol framework,which can be constructed by a linear method and ensure the global convergence.

关键词： Distributed network localization graph Laplaian sensor network

Single-shot non-line-of-sight imaging based on chromato-axial differential correlography

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Photonics Research 2024年第1期12卷 106-114页

作者： LINGFENG LIU SHUO ZHU WENJUN ZHANG LIANFA BAI ENLAI GUO JING HAN Jiangsu key laboratory of Spectral Imaging and intelligent Sense Nanjing University of Science and TechnologyNanjing 210094China

Non-line-of-sight(NLOS)imaging is a challenging task aimed at reconstructing objects outside the direct view of the observer.Nevertheless,traditional NLOS imaging methods typically rely on intricate and costly equipment to scan and sample the hidden object.These methods often suffer from restricted imaging resolution and require high system stability.Herein,we propose a single-shot high-resolution NLOS imaging method via chromato-axial differential correlography,which adopts low-cost continuous-wave lasers and a conventional camera.By leveraging the uncorrelated laser speckle patterns along the chromato-axis,this method can reconstruct hidden objects of diverse complexity using only one exposure measurement.The achieved background stability through singleshot acquisition,along with the inherent information redundancy in the chromato-axial differential speckles,enhances the robustness of the system against vibration and colored stain interference.This approach overcomes the limitations of conventional methods by simplifying the sampling process,improving system stability,and achieving enhanced imaging resolution using available equipment.This work serves as a valuable reference for the real-time development and practical implementation of NLOS imaging.

关键词： axial speckle overcome

Control Policy Learning Design for Vehicle Urban Positioning via BeiDou Navigation

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Journal of systems Science & Complexity 2024年第1期37卷 114-135页

作者： QIN Yahang ZHANG Chengye CHEN Ci XIE Shengli LEWIS Frank L School of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong key laboratory of IoT Information technology Guangzhou 510006China. Center for intelligent Batch Manufacturing Based on IoT technology key laboratory of intelligent Detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong-HongKong-Macao Joint laboratory for Smart Discrete Manufacturing Guangzhou 510006China key laboratory of intelligent Information Processing and system Integration of IoT Ministry of EducationGuangzhou 510006China. UTA Research Institute The University of Texas at ArlingtonFort WorthTX 76019USA

This paper presents a learning-based control policy design for point-to-point vehicle positioning in the urban environment via BeiDou navigation.While navigating in urban canyons,the multipath effect is a kind of interference that causes the navigation signal to drift and thus imposes severe impacts on vehicle localization due to the reflection and diffraction of the BeiDou signal.Here,the authors formulated the navigation control system with unknown vehicle dynamics into an optimal control-seeking problem through a linear discrete-time system,and the point-to-point localization control is modeled and handled by leveraging off-policy reinforcement learning for feedback control.The proposed learning-based design guarantees optimality with prescribed performance and also stabilizes the closed-loop navigation system,without the full knowledge of the vehicle dynamics.It is seen that the proposed method can withstand the impact of the multipath effect while satisfying the prescribed convergence rate.A case study demonstrates that the proposed algorithms effectively drive the vehicle to a desired setpoint under the multipath effect introduced by actual experiments of BeiDou navigation in the urban environment.

关键词： BeiDou navigation multipath effect prescribed convergence rate reinforcement learning urban localization.