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arXiv 2023年

作者： Fonseca, Joana Bhat, Sriharsha Lock, Matthew Stenius, Ivan Johansson, Karl H. The Division of Decision and Control Systems School of Electrical Engineering and Computer Science and Digital Futures Sweden The Department of Aeronautical and Vehicle Engineering School of Engineering Sciences Kth Royal Institute of Technology StockholmSE-100 44 Sweden

This paper investigates using satellite data to improve adaptive sampling missions, particularly for front tracking scenarios such as with algal blooms. Our proposed solution to find and track algal bloom fronts uses an Autonomous Underwater Vehicle (AUV) equipped with a sensor that measures the concentration of chlorophyll a and satellite data. The proposed method learns the kernel parameters for a Gaussian process (GP) model using satellite images of chlorophyll a from the previous days. Then, using the data collected by the AUV, it models chlorophyll a concentration online. We take the gradient of this model to obtain the direction of the algal bloom front and feed it to our control algorithm. The performance of this method is evaluated through realistic simulations for an algal bloom front in the Baltic sea, using the models of the AUV and the chlorophyll a sensor. We compare the performance of different estimation methods, from GP to curve interpolation using least squares. Sensitivity analysis is performed to evaluate the impact of sensor noise on the methods' performance. We implement our method on an AUV and run experiments in the Stockholm archipelago in the summer of 2022. Copyright © 2023, The Authors. All rights reserved.

关键词： Autonomous underwater vehicles

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On the Complexity of Computing the Maximal Positive Invariant Set

On the Complexity of Computing the Maximal Positive Invarian...

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European control Conference (ECC)

作者： Bogdan Gheorghe Florin Stoican Ionela Prodan Faculty of Automation Control and Computer Science National University of Science and Technology Politehnica Bucharest Romania Grenoble INP LCIS Univ. Grenoble Alpes Institute of Engineering and Management Univ. Grenoble Alpes Valence France

ISBN: (数字)9783907144107

ISBN: (纸本)9798331540920

Computing the maximal (robust) positive invari-ant (M(R)PI) set for linear dynamics and a polyhedral constraint set is well-known in the literature but, the effects and limitations of the different methods employed are not sufficiently clear, especially for high dimensional systems. In this paper we propose a systematic analysis of the existing techniques as well as the application of new ideas to accelerate the computation of the MPI set. This includes new stop conditions for the set recurrence that spans it. We analyze and compare these variations over a dynamical system whose dimension can be arbitrarily increased to draw conclusions about their relative strengths and weaknesses.

关键词： Systematics Europe Complexity theory Dynamical systems Predictive control

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Nonlinear control of dc/dc power converters with inherent current and power limitation

Nonlinear control of dc/dc power converters with inherent cu...

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Mediterranean Conference on control and Automation

作者： George C. Konstantopoulos Qing-Chang Zhong Department of Automatic Control and Systems Engineering The Univesity of Sheffield Sheffield S1 3JD U.K Department of Electrical and Computer Engineering Illinois Institute of Technology Chicago IL 60616 USA

ISBN: (纸本)9781467383479

A nonlinear controller with an inherent current-limiting capability is presented in this paper for different types of dc/dc power converters (boost, buck-boost). The proposed controller is based on the idea of applying a dynamic virtual resistance in series with the inductor of the converter, which varies according to a nonlinear dynamical system. It is shown that the proposed approach acts independently from the converter parameters (inductance, capacitance) or the load and has a generic structure that can be used to achieve different regulation scenarios, e.g. voltage, current or power regulation. Based on the nonlinear model of the boost and the buck-boost converter, it is analytically proven that the inductor current remains always bounded below a given maximum value using input-to-state stability theory under a suitable choice of the controller parameters. Hence, the proposed control strategy offers an inherent protection property since the power of the converter is limited below a given value during transients or unrealistic power demands. Simulation results for both types of dc/dc converters are presented to verify the desired controller performance.

关键词： Inductors Voltage control Resistance Nonlinear dynamical systems Load modeling Stability analysis Transient analysis Nonlinear dynamical systems inductors Load modeling Voltage regulation Transient analysis Converters Stability analysis nonlinear control power conversion unit Energy sources Series Resistance controllers boost converters series inductor stability theory

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Security analysis of control system anomaly detectors

Security analysis of control system anomaly detectors

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American control Conference

作者： David Umsonst Henrik Sandberg Alvaro A. Cardenas Department of Automatic Control in the School of Electrical Engineering at the KTH Royal Institute of Technology 10044 Stockholm Sweden Department of Computer Science in the Erik Jonsson School of Engineering at the University of Texas at Dallas 75080 Richardson United States of America

ISBN: (纸本)9781509045839

Two anomaly detectors for control systems are analyzed with respect to their sensitivity to malicious data injection attacks. A stateless anomaly detector based on the current residual signal is compared to a cumulative sum detector. The worst-case impact of a stealthy time-limited data injection attack is characterized for both detectors by a non-convex optimization problem and compared to determine which detector limits the impact the most. We prove that the problem can be solved by means of a set of convex optimization problems. Simulations verify that finding the right configuration for the cumulative sum is crucial to limit the worst-case attack impact more than with a stateless anomaly detector.

关键词： control systems analyzed detector anomaly Standing Orders control systems residual signal

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Selecting of global phenological field observations for validating coarse AVHRR-derived forest phenology products based on spatial heterogeneity and temporal consistency

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Ecological Informatics 2025年 90卷

作者： Qi Shao Chao Huang Yuanjun Xiao Li Liu Weiwei Liu Ran Huang Chang Zhou Wei Weng Jingfeng Huang Key Laboratory of Environmental Remediation and Ecological Health Ministry of Education Zhejiang University Hangzhou 310058 China State Key Laboratory of Soil Pollution Control and Safety Zhejiang University Hangzhou 310058 China Institute of Applied Remote Sensing and Information Technology Zhejiang University Hangzhou 310058 China Key Laboratory of Agricultural Remote Sensing and Information Systems Hangzhou 310058 China Key Laboratory of National Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed College of Forestry Jiangxi Agricultural University Nanchang 330045 China Hubei Key Laboratory of Intelligent Vision Based Monitoring for Hydroelectric Engineering College of Computer and Information Technology China Three Gorges University Yichang 443002 China Department of Geography and Spatial Information Techniques Ningbo University Ningbo 315211 China School of Automation Hangzhou Dianzi University Xiasha Higher Education Zone Hangzhou 310058 China

Global phenological field observations play a crucial role in validating remote sensing products and algorithms. However, due to the spatial mismatch and scale effect between the field observations and the pixels of remote sensing phenology products, a direct comparison often leads to scale errors and increased uncertainty. Therefore, evaluating the spatial representativeness of field observations for remote sensing product validation is essential. This study developed a novel “bottom-up” evaluation framework named MSPT ( M ain land cover type, S patial heterogeneity, P oint-area consistency and T emporal consistency), which comprehensively assesses the spatial representativeness of forest phenological field observations within the coarse spatial scale. Based on MSPT method, the capability of global forest phenological field observations to support coarse-scale remote sensing validation was evaluated. Compared with the general method, MSPT significantly improved validation performance. For the start of the growing season (SOS), the root mean square error (RMSE) decreased from 49.70 to 33.75 days, and the percent bias (PBIAS) changed from −0.14 to 0.03. For the end of the growing season (EOS), the RMSE was reduced from 83.42 to 42.53 days, and the PBIAS decreased from 0.15 to 0.08. These findings demonstrate that MSPT enhances the reliability of validation datasets and effectively reducing uncertainty in the evaluation of coarse AVHRR-derived forest phenology products. The framework offers new insights into resolving the scale mismatch between field observations and the pixels of remote sensing products.

关键词： Forest phenology Field observations Spatial representativeness Spatial mismatch Satellite product AVHRR Advanced Very High Resolution Radiometer CERN Chinese Ecosystem Research Network CNW Canada nature watch DBF Deciduous Broadleaf Forests DOY Date of year EBF Evergreen Broadleaf Forests ENF Evergreen Needleleaf Forest EOS The end of the growing season GEE Google Earth Engine GPP Gross primary productivity HBEF Hubbard Brook Experimental Forest HF Harvard Forest IPS Instantaneous Phase Synchrony MAD Mean Absolute Deviation MCD12Q1 MODIS Collection 6.1 (C61) Land Cover Type Product MF Mixed Forests MIPS Mean Instantaneous phase synchrony MLCTP Main Land Cover Type Proportion MSPT Main land cover type - Spatial heterogeneity - Point-area consistency - Temporal consistency NC Nature's Calendar PBIAS Percent bias PEP725 Pan European Phenology Project RAE Relative absolute error RMSE Root mean square error sd standard deviation SOS The start of the growing season USA-NPN USA National Phenology Network VIPPHEN Vegetation Index and Phenology (VIP) Phenology Dataset WI Willmott's Index of Agreement

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Adaptive droop control applied to distributed generation inverters connected to the grid

Adaptive droop control applied to distributed generation inv...

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IEEE International Symposium on Industrial Electronics (ISIE)

作者： Juan C. Vasquez Josep M. Guerrero Eduard Gregorio Pedro Rodriguez Remus Teodorescu Frede Blaabjerg Department Automatic Control Systems and Computer Engineering Universitat Politecnica de Catalunya Barcelona Spain Department of Electrical Engineering Universitat Politecnica de Catalunya Terrassa Spain Institute of Energy Technology University of Aalborg Aalborg Denmark

This paper proposes a novel control for voltage source inverters connected to the grid. The control scheme is based on the droop method, and it uses some estimated variables from the grid such as the voltage and the frequency, and the magnitude and angle of the grid impedance. Hence, the inverter is able to inject independently active and reactive power to the grid. The controller provides a proper dynamics decoupled from the grid impedance. Simulation results are provided in order to show the feasibility of the control proposed.

关键词： Distributed control Programmable control Adaptive control Inverters Voltage Frequency Impedance Reactive power Adaptive filters Automatic control

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Generalized Multi-kernel Maximum Correntropy Kalman Filter for Disturbance Estimation

arXiv

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arXiv 2023年

作者： Li, Shilei Shi, Dawei Lou, Yunjiang Zou, Wulin Shi, Ling The Department of Electronic and Computer Engineering The Hong Kong University of Science and Technology Hong Kong The School of Automation Beijing Institute of Technology China The State Key Laboratory of Robotics and System School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen Shenzhen518055 China Xeno Dynamics Control Department Xeno Dynamics Co. Ltd Shenzhen518055 China

Disturbance observers have been attracting continuing research efforts and are widely used in many applications. Among them, the Kalman filter-based disturbance observer is an attractive one since it estimates both the state and the disturbance simultaneously, and is optimal for a linear system with Gaussian noises. Unfortunately, The noise in the disturbance channel typically exhibits a heavy-tailed distribution because the nominal disturbance dynamics usually do not align with the practical ones. To handle this issue, we propose a generalized multi-kernel maximum correntropy Kalman filter for disturbance estimation, which is less conservative by adopting different kernel bandwidths for different channels and exhibits excellent performance both with and without external disturbance. The convergence of the fixed point iteration and the complexity of the proposed algorithm are given. Simulations on a robotic manipulator reveal that the proposed algorithm is very efficient in disturbance estimation with moderate algorithm complexity. Copyright © 2023, The Authors. All rights reserved.

关键词： Kalman filters

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Learning of Nash Equilibria in Risk-Averse Games

Learning of Nash Equilibria in Risk-Averse Games

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American control Conference (ACC)

作者： Zifan Wang Yi Shen Michael M. Zavlanos Karl H. Johansson Division of Decision and Control Systems School of Electrical Enginnering and Computer Science KTH Royal Institute of Technology and also with Digital Futures Stockholm Sweden Department of Mechanical Engineering and Materials Science Duke University Durham NC USA

ISBN: (数字)9798350382655

ISBN: (纸本)9798350382662

This paper considers risk-averse learning in convex games involving multiple agents that aim to minimize their individual risk of incurring significantly high costs. Specifically, the agents adopt the conditional value at risk (CVaR) as a risk measure with possibly different risk levels. To solve this problem, we propose a first-order risk-averse leaning algorithm, in which the CVaR gradient estimate depends on an estimate of the Value at Risk (VaR) value combined with the gradient of the stochastic cost function. Although estimation of the CVaR gradients using finitely many samples is generally biased, we show that the accumulated error of the CVaR gradient estimates is bounded with high probability. Moreover, assuming that the risk-averse game is strongly monotone, we show that the proposed algorithm converges to the risk-averse Nash equilibrium. We present numerical experiments on a Cournot game example to illustrate the performance of the proposed method.

关键词： Reactive power Costs Estimation Games Nash equilibrium Numerical simulation Cost function

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Image Analysis for E-Healthcare Systems using Multi-Biometric Recognition Model

Image Analysis for E-Healthcare Systems using Multi-Biometri...

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Advancement in Computation & computer Technologies (InCACCT), International Conference on

作者： Naman Bansal Pranav Arora Deepak Kumar Sharma Koyel Datta Gupta Chandana Kuntala Department of Instrumentation and Control Engineering Netaji Subhas Institute of Technology University of Delhi New Delhi India Department of Information Technology Indira Gandhi Delhi Technical University for Women New Delhi India Department of Computer Science and Engineering Maharaja Surajmal Institute of Technology New Delhi India Department of Information Technology Indira Gandhi Delhi Technical University for Women New Delhi India

With the dawn of e-Healthcare systems, Medical Record Management has become an important research problem. The storage and organization of medical records have made relatively little progress in a world of constantly emerging new technologies and continuous innovation. Many hospitals keep the records on paper, which raises many challenges, including but not limited to a significant amount of time for searching and retrieving a specific record, high maintenance costs, lack of backup, and limited security. Although the inclusion of technology has made this task far more efficient and secure, there is still much that can be done to improve it. This paper proposes a double index-based approach for mapping medical records directly to a patient’s biometrics which would take advantage of the uniqueness of biometrics to identify a patient. The proposed multi-biometric model achieves an accuracy of 97% and an F 1 score of 0.9814.

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Complete gradient clustering algorithm for features analysis of X-ray images

Advances in Intelligent and Soft Computing

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Advances in Intelligent and Soft Computing 2010年 69卷 15-24页

作者： Charytanowicz, Malgorzata Niewczas, Jerzy Kulczycki, Piotr Kowalski, Piotr A. Lukasik, Szymon Zak, Slawomir Institute of Mathematics and Computer Science John Paul II Catholic University of Lublin Konstantynów 1 H PL 20-708 Lublin Poland Department of Automatic Control and Information Technology Cracow University of Technology Warszawska 24 Cracow PL 31-155 Poland Systems Research Institute Polish Academy of Sciences Newelska 6 Warsaw PL 01-447 Poland

ISBN: (纸本)9783642131042

Methods based on kernel density estimation have been successfully applied for various data mining tasks. Their natural interpretation together with suitable properties make them an attractive tool among others in clustering problems. In this paper, the Complete Gradient Clustering Algorithm has been used to investigate a real data set of grains. The wheat varieties, Kama, Rosa and Canadian, characterized by measurements of main grain geometric features obtained by X-ray technique, have been analyzed. The proposed algorithm is expected to be an effective tool for recognizing wheat varieties. A comparison between the clustering results obtained from this method and the classical k-means clustering algorithm shows positive practical features of the Complete Gradient Clustering Algorithm. © 2010 Springer-Verlag Berlin Heidelberg.

关键词： Clustering algorithms

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