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Grid-following three-phase inverter with RMS current-limiting property 12

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Grid-following three-phase inverter with RMS current-limitin...

12th Mediterranean Conference on Power Generation, Transmission, Distribution and Energy Conversion, MEDPOWER 2020

作者： Skentzos, Panagiotis Konstantopoulos, George C. Dept. of Automatic Control and Systems Engineering University of Sheffield Mappin Street SheffieldS1 3JD United Kingdom Dept. of Electrical and Computer Engineering University of Patras Rio26504 Greece

ISBN: (纸本)9781839535635

A novel nonlinear controller that inherently limits the RMS value of a three-phase grid-following inverter current is presented in this paper. Using the dynamic model of the inverter in the rotating dq reference frame, a nonlinear control scheme is formulated to ensure accurate real and reactive power regulation with RMS current limitation that avoids the use of saturation units with upper/lower limit adaptation, as commonly used in the existing approaches. In particular, it is analytically proven by using fundamental nonlinear systems theory, that the RMS value of the inverter current will never violate a given maximum value, both during the transient response and at the steady-state. Moreover, a detailed root locus analysis is provided to guarantee the asymptotic stability of the desired equilibrium point for the closed-loop system. Finally, to validate the proposed controller performance, simulation results of a grid-following three-phase inverter equipped with the proposed control approach are presented under both normal and unrealistic values of the real and reactive power setpoints. © 2020 Institution of engineering and Technology. All rights reserved.

关键词： Asymptotic stability

Empowering cyberphysical systems of systems with intelligence

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arXiv 2021年

作者： Nousias, Stavros Piperigkos, Nikos Arvanitis, Gerasimos Fournaris, Apostolos Lalos, Aris S. Moustakas, Konstantinos Industrial Systems Institute Athena Research Center Patras Science Park Greece Dept. of ELectrical and Computer Engineering University of Patras Greece

Cyber Physical systems have been going into a transition phase from individual systems to a collecttives of systems that collaborate in order to achieve a highly complex cause, realizing a system of systems approach. The automotive domain has been making a transition to the system of system approach aiming to provide a series of emergent functionality like traffic management, collaborative car fleet management or large-scale automotive adaptation to physical environment thus providing significant environmental benefits (e.g air pollution reduction) and achieving significant societal impact. Similarly, large infrastructure domains, are evolving into global, highly integrated cyber-physical systems of systems covering all parts of the value chain. In practice, there are significant challenges in CPSoS applicability and usability to be addressed, i.e. even a small CPSoS such as a car consists several subsystems Decentralization of CPSoS appoints tasks to individual CPSs within the System of systems. CPSoSs are heterogenous systems. They comprise of various, autonomous, CPSs, each one of them having unique performance capabilities, criticality level, priorities and pursued goals. all CPSs must also harmonically pursue system-based achievements and collaborate in order to make system-of-system based decisions and implement the CPSoS functionality. This survey will provide a comprehensive review on current best practices in connected cyberphysical systems. The basis of our investigation is a dual layer architecture encompassing a perception layer and a behavioral layer. Perception algorithms with respect to scene understanding (object detection and tracking, pose estimation), localization mapping and path planning are thoroughly investigated. Behavioural part focuses on decision making and human in the loop control. © 2021, CC BY.

关键词： Decision making

2-D Directed Formation control Based on Bipolar Coordinates

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arXiv 2021年

作者： Mehdifar, Farhad Bechlioulis, Charalampos P. Hendrickx, Julien M. Dimarogonas, Dimos V. The Division of Decision and Control Systems KTH Royal Institute of Technology Stockholm Sweden The Division of Systems and Control The Department of Electrical and Computer Engineering University of Patras Patra Greece INMA ICTEAM institute UCLouvain Louvain-la-Neuve Belgium

This work proposes a novel 2-D formation control scheme for acyclic triangulated directed graphs (a class of minimally acyclic persistent graphs) based on bipolar coordinates with (almost) global convergence to the desired shape. Prescribed performance control is employed to devise a decentralized control law that avoids singularities and introduces robustness against external disturbances while ensuring predefined transient and steady-state performance for the closed-loop system. Furthermore, it is shown that the proposed formation control scheme can handle formation maneuvering, scaling, and orientation specifications simultaneously. Additionally, the proposed control law is implementable in agents' arbitrarily oriented local coordinate frames using only low-cost onboard vision sensors, which are favorable for practical applications. Finally, a formation maneuvering simulation study verifies the proposed approach. Copyright © 2021, The Authors. All rights reserved.

关键词： Directed graphs

Overcoming the Fear of the Dark: Occlusion-Aware Model-Predictive Planning for Automated Vehicles Using Risk Fields

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arXiv 2023年

作者： van der Ploeg, Chris Nyberg, Truls Sánchez, José Manuel Gaspar Silvas, Emilia van de Wouw, Nathan Netherlands Organisation for Applied Scientific Research Integrated Vehicle Safety Group Helmond5700 AT Netherlands Eindhoven University of Technology Dynamics and Control Group Mechanical Engineering Dept. P.O. Box 513 Eindhoven5600 MB Netherlands Eindhoven University of Technology Control Systems Technology Group Mechanical Engineering Dept. P.O. Box 513 Eindhoven5600 MB Netherlands KTH Royal Institute of Technology Division of Robotics Perception and Learning School of Electrical Engineering and Computer Science Stockholm100 44 Sweden Scania CV AB Södertälje151 87 Sweden

As vehicle automation advances, motion planning algorithms face escalating challenges in achieving safe and efficient navigation. Existing Advanced Driver Assistance systems (ADAS) primarily focus on basic tasks, leaving unexpected scenarios for human intervention, which can be error-prone. Motion planning approaches for higher levels of automation in the state-of-the-art are primarily oriented toward the use of risk- or anti-collision constraints, using over-approximates of the shapes and sizes of other road users to prevent collisions. These methods however suffer from conservative behavior and the risk of infeasibility in high-risk initial conditions. In contrast, our work introduces a novel multi-objective trajectory generation approach. We propose an innovative method for constructing risk fields that accommodates diverse entity shapes and sizes, which allows us to also account for the presence of potentially occluded objects. This methodology is integrated into an occlusion-aware trajectory generator, enabling dynamic and safe maneuvering through intricate environments while anticipating (potentially hidden) road users and traveling along the infrastructure toward a specific goal. Through theoretical underpinnings and simulations, we validate the effectiveness of our approach. This paper bridges crucial gaps in motion planning for automated vehicles, offering a pathway toward safer and more adaptable autonomous navigation in complex urban contexts. Copyright © 2023, The Authors. All rights reserved.

关键词： Motion planning

Dynamic Resilient Graph Games for State-Dependent Jamming Attacks Analysis on Multi-Agent systems

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IFAC-PapersOnLine 2020年第2期53卷 3421-3426页

作者： Yurid Nugraha Ahmet Cetinkaya Tomohisa Hayakawa Hideaki Ishii Quanyan Zhu Dept. of Systems and Control Engineering Tokyo Institute of Technology Tokyo 152-8552 Japan Information Systems Architecture Science Research Division National Institute of Informatics Tokyo 101-8430 Japan Dept. of Computer Science Tokyo Insitute of Technology Yokohama 226-8502 Japan Dept. of Electrical and Computer Engineering New York University Brooklyn NY 11201 USA

A cybersecurity problem for a multi-agent consensus problem is investigated through a dynamic game formulation. Specifically, we consider a game repeatedly played between a jamming attacker and a defender. The attacker attempts to jam the links between a number of agents to delay their consensus. On the other hand, the defender tries to maintain the connection between agents by attempting to recover some of the jammed links with the goal of achieving faster consensus. In each game, the players decide which links to attack/recover and for how long to continue doing so based on a Lyapunov-like function representing the largest difference between the states of the agents. We analyze the subgame perfect equilibrium of the game and obtain an upper bound of the consensus time that is influenced by the strategies of the players. The results are illustrated with a numerical example.

关键词： Multi-agent systems Consensus problem Game theory Cybersecurity

DC Microgrids under Denial of Service Attacks: Feasibility and Stability Issues 12

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DC Microgrids under Denial of Service Attacks: Feasibility a...

12th Annual IEEE Energy Conversion Congress and Exposition, ECCE 2020

作者： Liu, Jianzhe Cui, Bai Chen, Bo Lu, Xiaonan Qiu, Feng Mazumder, Sudip Argonne National Laboratory Energy Systems Division Lemont United States National Renewable Energy Laboratory Power Systems Engr. Center Golden United States Temple University College of Engineering Philadelphia United States University of Illinois at Chicago Dept. Electrical and Computer Engr. Chicago United States

ISBN: (数字)9781728158266

ISBN: (纸本)9781728158266

Distributed control has been extensively studied for a DC microgrid to coordinate multiple grid assets where each asset can generate its own control decisions based on communications within its neighborhood. Nevertheless, such a control strategy usually has a strong dependence on active information exchange and needs to always maintain a pre-determined communication graph. This makes it vulnerable to cyber attacks, especially denial of service (DoS) attacks that block communication channels that effectively change the communication graph. In this paper, we study two potential impacts of DoS attacks: the inability to maintain steady-state and dynamical generation-demand balance, i.e. the feasibility and stability issues. We develop a mathematical model to describe the cyber-induced system steady-state and dynamical performance. The model reveals the impacts of DoS attacks and enables formal analysis. Case studies are shown to verify the proposed work. © 2020 IEEE.

关键词： Denial-of-service attack

Optimal Periodic Multi-Agent Persistent Monitoring of a Finite Set of Targets with Uncertain States

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Optimal Periodic Multi-Agent Persistent Monitoring of a Fini...

American control Conference

作者： Samuel C. Pinto Sean B. Andersson Julien M. Hendrickx Christos G. Cassandras Dept. of Mechanical Engineering Boston University Boston MA USA Dept. of Electrical and Computer Engineering Boston University Boston MA USA Division of Systems Engineering Boston University Boston MA USA

ISBN: (数字)9781538682661

ISBN: (纸本)9781538682678

We investigate the problem of persistently monitoring a finite set of targets with internal states that evolve with linear stochastic dynamics using a finite set of mobile agents. We approach the problem from the infinite-horizon perspective, looking for periodic movement schedules for the agents. Under linear dynamics and some standard assumptions on the noise distribution, the optimal estimator is a Kalman-Bucy filter. It is shown that when the agents are constrained to move only over a line and that they can see at most one target at a time, the optimal movement policy is such that the agent is always either moving with maximum speed or dwelling at a fixed position. Periodic trajectories of this form admit finite parameterization, and we show how to compute a stochastic gradient estimate of the performance with respect to the parameters that define the trajectory using Infinitesimal Perturbation Analysis. A gradient-descent scheme is used to compute locally optimal parameters. This approach allows us to deal with a very long persistent monitoring horizon using a small number of parameters.

关键词： Agents Finite Periodic maximum speed trajectory Mobile agents Optimal

Can information technology affects people’s behavior and opinion? A way to identify it.

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IFAC-PapersOnLine 2019年第25期52卷 498-503页

作者： Georgios Mandellos Dimitris Tsipianitis Dimitrios Lymberopoulos Telecommunications & Information Technology Division Electrical & Computer Engineering Department University of Patras Rion GR-26504 Greece Systems & Automatic Control Division Electrical & Computer Engineering Department University of Patras Rion GR-26504 Greece

The scope of this study is to determine if the information technology can affects people’s behavior and or opinion. A way to identify it is using a tool to collect answers using or not using the technology. How? Making surveys. Nowadays there are 2 main categories of survey administration. The traditional paper data collection method and the relatively new web-based method. Although the two acquisition processes are completely different, each one has its own advantages and disadvantages, facility or difficulty, adoption or not. The scope of this paper is to study factors that affect each survey type and find the preferable questionnaire administration method. To compare survey media, responses from university students were taken. We tried to investigate the reliability, honesty, item mean, response rate, completeness of data, and also made factor analysis comparisons across survey media. The experiment was applied on the same audience and theme, using different methods. From the data analyses the results between paper and online media in this experiment appear to be major, and seem to have a significant effect on overall results. The majority of differences found on questions related with personal criticism (where anonymity plays a significant role), and on response rates.

关键词： information technology people’s opinion surveys people’s behavior

Explainability of Intelligent Transportation systems using Knowledge Compilation: a Traffic Light controller Case

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arXiv 2020年

作者： Wollenstein-Betech, Salomón Muise, Christian Cassandras, Christos G. Paschalidis, Ioannis Ch. Khazaeni, Yasaman Dept. of Electrical and Computer Engineering Division of Systems Engineering Boston University BostonMA United States School of Computing Queen’s University KingstonON Canada IBM Research AI CambridgeMA United States

Usage of automated controllers which make decisions on an environment are widespread and are often based on black-box models. We use Knowledge Compilation theory to bring explainability to the controller’s decision given the state of the system. For this, we use simulated historical state-action data as input and build a compact and structured representation which relates states with actions. We implement this method in a Traffic Light control scenario where the controller selects the light cycle by observing the presence (or absence) of vehicles in different regions of the incoming roads. Copyright © 2020, The Authors. All rights reserved.

关键词： controllers