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Trajectory planning and control for drone replacement for multidrone cinematography

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IFAC-PapersOnLine 2019年第12期52卷 334-339页

作者： Marta Marques Bruno J. Guerreiro Rita Cunha Carlos Silvestre Institute for Systems and Robotics (ISR-Lisbon) LARSYS Instituto Superior Tecnico 1049-001 Lisbon Portugal Dep. of Electrical and Computer Eng. and CTS-Uninova Universidade Nova de Lisboa Caparica 2829-516 Portugal Dep. of Electrical and Computer Eng. Faculty of Science and Technology University of Macau China and also on leave from Instituto Superior Tecnico Universidade de Lisboa Lisbon Portugal

This work addresses the problem of trajectory planning and control for a team of drones, so that a vehicle that is following a target as part of a multi-vehicle formation flight can be safely replaced with minimum impact on the formation objectives. An optimal trajectory generation method is presented, which relies on formulating a nonlinear optimization problem with constraints imposed by the physical limitations of the vehicle, the formation, and the surrounding environment, including nonlinear constraints to enforce inter-vehicle collision avoidance and clear visibility of the target. An online planning and control strategy is also implemented through a Nonlinear Model Predictive Control problem, based on the dynamic model of the system, a quadratic objective function, and a set of constraints, that again include collision avoidance and clear visibility. The proposed algorithms are validated in software-in-the-loop simulations that include the autopilot software.

关键词： UAV dynamics control guidance navigation Formation flying

Dense dilated network with probability regularized walk for vessel detection

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arXiv 2019年

作者： Mou, Lei Chen, Li Cheng, Jun Gu, Zaiwang Zhao, Yitian Liu, Jiang School of Computer Science and Technology Wuhan University of Science and Technology Wuhan430081 China Hubei Province Key Laboratory of Intelligent Information Processing and Real-time Industrial System Wuhan University of Science and Technology Wuhan430081 China Cixi Institute of Biomedical Engineering Chinese Academy of Sciences Zhejiang315201 China UBTech Research UBTech Robotics Corp Ltd Guangdong518055 China Department of Computer Science and Engineering Southern University of Science and Technology Guangdong518055 China Cixi Institute of Biomedical Engineering Ningbo Institute of Industrial Technology Chinese Academy of Sciences Zhejiang315201 China

The detection of retinal vessel is of great importance in the diagnosis and treatment of many ocular diseases. Many methods have been proposed for vessel detection. However, most of the algorithms neglect the connectivity of the vessels, which plays an important role in the diagnosis. In this paper, we propose a novel method for retinal vessel detection. The proposed method includes a dense dilated network to get an initial detection of the vessels and a probability regularized walk algorithm to address the fracture issue in the initial detection. The dense dilated network integrates newly proposed dense dilated feature extraction blocks into an encoder-decoder structure to extract and accumulate features at different scales. A multi-scale Dice loss function is adopted to train the network. To improve the connectivity of the segmented vessels, we also introduce a probability regularized walk algorithm to connect the broken vessels. The proposed method has been applied on three public data sets: DRIVE, STARE and CHASE_DB1. The results show that the proposed method outperforms the state-of-the-art methods in accuracy, sensitivity, specificity and also area under receiver operating characteristic curve. Copyright © 2019, The Authors. All rights reserved.

关键词： Diagnosis

Scheduling measurements and controls over networks — Part II: Rollout strategies for simultaneous protocol and controller design

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Scheduling measurements and controls over networks — Part I...

American Control Conference (ACC)

作者： D. J. Antunes W. P. M. H. Heemels J. P. Hespanha C. J. Silvestre Hybrid and Networked Systems Group Department of Mechanical Engineering Eindhovan University of Technology Netherlands Department of Electrical and Computer Engineering University of California Santa Barbara CA USA Institute for Systems and Robotics Instituto Superior Técnico Lisboa Portugal Faculty of Science and Technology University of Macau Taipa Macao China

ISBN: (纸本)9781457710957

We consider a networked control system where a plant is connected to a remote controller via a shared network that allows only one user to transmit at a given time. At each transmission time, the controller decides between sampling one of the plant's sensors or transmitting control data to the plant. We tackle the problem of simultaneously designing a policy for scheduling decisions and a policy for control inputs so as to optimize a quadratic objective. Using the framework of dynamic programming, we propose a rollout strategy by which the scheduling and control decisions are determined at each transmission time as the ones that lead to optimal performance over a given horizon assuming that from then on controller and sensors transmit in a periodic order and the control law is a standard optimal law for periodic systems. We show that this rollout strategy results in a protocol where scheduling decisions are based on the state estimate and error covariance matrix of a Kalman estimator, and must be determined on-line. We contrast the solution to this problem with the solution to the seemingly similar sensor scheduling problem where optimal scheduling decisions can be determined off-line. We highlight how the protocol obtained from the rollout algorithm can be implemented in a distributed way in broadcast networks. Moreover, it follows by construction of rollout algorithms that our proposed scheduling method can outperform any periodic scheduling of transmissions.

关键词： Sensors Protocols Scheduling Optimal scheduling Covariance matrix Processor scheduling Networked control systems

From localized to propagating surface plasmon resonances in Au nanoparticle-coated optical fiber sensors and its implications in biosensing

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Photonics Research 2024年第10期12卷 2166-2177页

作者： PAULO S.S.DOS SANTOS JOÃO P.MENDES JORGE PÉREZ-JUSTE I.PASTORIZA-SANTOS JOSÉM.M.M.DE ALMEIDA LUÍS C.C.COELHO INESC TEC–Institute of Systems and Computer Engineering Technology and Scienceand Department of PhysicsFaculty of SciencesUniversity of PortoRua do Campo Alegre4169-007 PortoPortugal Faculty of Engineering University of PortoRua Dr.Roberto Frias4200-465 PortoPortugal CINBIO Universidade de VigoCampus Universitario LagoasMarcosende36310 VigoSpain SERGAS-UVIGO Galicia Sur Health Research Institute(IIS Galicia Sur)36312 VigoSpain Department of Physics School of Science and TechnologyUniversity of Trás-os-Montes e Alto Douro5001-801 Vila RealPortugal

Nanoparticle-based plasmonic optical fiber sensors can exhibit high sensing performance,in terms of refractive index sensitivities(RISs).However,a comprehensive understanding of the factors governing the RIS in this type of sensor remains limited,with existing reports often overlooking the presence of surface plasmon resonance(SPR)phenomena in nanoparticle(NP)assemblies and attributing high RIS to plasmonic coupling or waveguiding ***,using plasmonic optical fiber sensors based on spherical Au nanoparticles,we investigate the basis of their enhanced RIS,both experimentally and *** bulk behavior of assembled Au NPs on the optical fiber was investigated using an effective medium approximation(EMA),specifically the gradient effective medium approximation(GEMA).Our findings demonstrate that the Au-coated optical fibers can support the localized surface plasmon resonance(LSPR)as well as SPR in particular ***,we found that the nanoparticle sizes and surface coverage dictate which effect takes precedence in determining the RIS of the *** data,in line with numerical simulations,revealed that increasing the Au NP diameter from 20 to 90 nm(15%surface coverage)led to an RIS increase from 135 to 6998 nm/RIU due to a transition from LSPR to SPR ***,increasing the surface coverage of the fiber from 9%to 15%with 90 nm Au nanoparticles resulted in anincrease in RIS from 1297(LSPR)to 6998 nm/RIU(SPR).Hence,we ascribe the exceptional performance of these plasmonic optical fibers primary to SPR effects,as evidenced by the nonlinear RIS *** outstanding RIS of these plasmonic optical fibers was further demonstrated in the detection of thrombin protein,achieving very low limits of *** findings support broader applications of high-performance NP-based plasmonic optical fiber sensors in areas such as biomedical diagnostics,environmental monitoring,and chemical analysis.

关键词： fiber surface fibers

DECOMPOSITION OF INDUSTRIAL systems FOR ENERGY EFFICIENCY OPTIMIZATION WITH OPTTOPO

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arXiv 2022年

作者： Thiele, Gregor Johanni, Theresa Sommer, David Krüger, Jörg Department for Process Automation and Robotics Fraunhofer Institute for Production Systems and Design Technology IPK Germany Faculty of Electrical Engineering and Computer Science Technical University of Berlin Berlin Germany Weierstrass Institute for Applied Analysis and Stochastics Berlin Germany Institute for Machine Tools and Factory Management Technical University of Berlin Berlin Germany

The operation of industrial facilities is a broad field for optimization. Industrial plants are often a) composed of several components, b) linked using network technology, c) physically interconnected and d) complex regarding the effect of set-points and operating points in every entity. This leads to the possibility of overall optimization but also to a high complexity of the emerging optimization problems. The decomposition of complex systems allows the modeling of individual models which can be structured according to the physical topology. A method for energy performance indicators (EnPI) helps to formulate an optimization problem. The optimization algorithm OptTopo achieves efficient set-points by traversing a graph representation of the overall system. © 2022, CC BY.

关键词： Optimization

Modular Adaptive Aerial Manipulation under Unknown Dynamic Coupling Forces

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arXiv 2024年

作者： Yadav, Rishabh Dev Dantu, Swati Pan, Wei Sun, Sihao Roy, Spandan Baldi, Simone Department of Computer Science The Univerity of Manchester United Kingdom Multi-robot systems group Faculty of Electrical Engineering Czech Technical University Prague Czech Republic Department of Cognitive Robotics Delft Univesrity of Technology Netherlands Robotics Research Center International Institute of Information Technology Hyderabad India School of Mathematics Southeast University Nanjing China

Successful aerial manipulation largely depends on how effectively a controller can tackle the coupling dynamic forces between the aerial vehicle and the manipulator. However, this control problem has remained largely unsolved as the existing control approaches either require precise knowledge of the aerial vehicle/manipulator inertial couplings, or neglect the state-dependent uncertainties especially arising during the interaction phase. This work proposes an adaptive control solution to overcome this long standing control challenge without any a priori knowledge of the coupling dynamic terms. Additionally, in contrast to the existing adaptive control solutions, the proposed control framework is modular, that is, it allows independent tuning of the adaptive gains for the vehicle position sub-dynamics, the vehicle attitude sub-dynamics, and the manipulator sub-dynamics. Stability of the closed loop under the proposed scheme is derived analytically, and real-time experiments validate the effectiveness of the proposed scheme over the state-of-the-art approaches. © 2024, CC BY.

关键词： Adaptive control systems

RF chain reduction for MIMO systems: A hardware prototype

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arXiv 2019年

作者： Gong, Tierui Shlezinger, Nir Ioushua, Shahar Stein Namer, Moshe Yang, Zhijia Eldar, Yonina C. State Key Lab of Robotics Key Lab of Networked Control Systems Shenyang Institute of Automation Chinese Academy of Sciences Shenyang110016 China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of Sciences Shenyang110016 China University of Chinese Academy of Sciences Beijing100049 China Faculty of Mathematics and Computer Science Weizmann Institute of Science Rehovot Israel School of Electrical Engineering Tel Aviv University Tel Aviv Israel Faculty of Electrical Engineering Technion Haifa Israel

RF chain circuits play a major role in digital receiver architectures, allowing passband communication signals to be processed in baseband. When operating at high frequencies, these circuits tend to be costly. This increased cost imposes a major limitation on future multiple-input multiple-output (MIMO) communication technologies. A common approach to mitigate the increased cost is to utilize hybrid architectures, in which the received signal is combined in analog into a lower dimension, thus reducing the number of RF chains. In this work we present a hardware prototype implementing analog combining for RF chain reduction. The prototype consists of a specially designed configurable combining board as well as a dedicated experimental setup. Our hardware prototype allows to evaluate the effect of analog combining in MIMO systems using actual communication signals. The experimental study, which focuses on channel estimation accuracy in MIMO channels, demonstrates that using the proposed prototype, the achievable channel estimation performance is within a small gap in a statistical sense from that obtained using a costly receiver in which each antenna is connected to a dedicated RF chain. Furthermore, in the considered scenarios, this gap becomes negligible when the reduction rate, i.e., the ratio of the number of RF chains to the number of antennas, is above 62.5%. Copyright © 2019, The Authors. All rights reserved.

关键词： Channel estimation

Automated Controller Placement for Software-Defined Networks to Resist DDoS Attacks

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computers, Materials & Continua 2021年第9期68卷 3147-3165页

作者： Muhammad Reazul Haque Saw Chin Tan Zulfadzli Yusoff Kashif Nisar Lee Ching Kwang Rizaludin Kaspin Bhawani Shankar Chowdhry Rajkumar Buyya Satya Prasad Majumder Manoj Gupta Shuaib Memon Faculty of Computing&Informatics Multimedia UniversityPersiaran MultimediaCyberjaya63100SelangorMalaysia Faculty of Engineering Multimedia UniversityPersiaran MultimediaCyberjaya63100SelangorMalaysia Faculty of Computing and Informatics University Malaysia SabahJalan UMSKota Kinabalu Sabah88400Malaysia Telekom Malaysia Research&Development TM Innovation CentreCyberjaya63000SelangorMalaysia National Center of Robotics and Automation Mehran University of Engineering&TechnologyJamshoroPakistan Department of Computer Science and Engineering Hanyang UniversitySeoul04763South Korea School of Electrical and Electronic Engineering Nanyang Technological University639798Singapore Cloud Computing and Distributed Systems Laboratory The University of MelbourneMelbourneVIC 3053Australia Department of Electrical and Electronic Engineering Bangladesh University of Engineering and Technology(BUET)Dhaka1205Bangladesh Department of Electronics and Communication Engineering JECRC UniversityVidhaniJaipur303905India Auckland Institute of Studies Mt AlbertAucklandNew Zealand

In software-defined networks(SDNs),controller placement is a critical factor in the design and planning for the future Internet of Things(IoT),telecommunication,and satellite communication *** research has concentrated largely on factors such as reliability,latency,controller capacity,propagation delay,and energy ***,SDNs are vulnerable to distributed denial of service(DDoS)attacks that interfere with legitimate use of the *** ever-increasing frequency of DDoS attacks has made it necessary to consider them in network design,especially in critical applications such as military,health care,and financial services networks requiring high *** propose a mathematical model for planning the deployment of SDN smart backup controllers(SBCs)to preserve service in the presence of DDoS *** a number of input parameters,our model has two distinct ***,it determines the optimal number of primary controllers to place at specific locations or nodes under normal operating ***,it recommends an optimal number of smart backup controllers for use with different levels of DDoS *** goal of the model is to improve resistance to DDoS attacks while optimizing the overall cost based on the *** simulated results demonstrate that the model is useful in planning for SDN reliability in the presence of DDoS attacks while managing the overall cost.

关键词： SDN automated controller placement SBC ILP DDoS attack

Pallet and Pocket Detection Based on Deep Learning Techniques

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Pallet and Pocket Detection Based on Deep Learning Technique...

Iberian robotics Conference (ROBOT)

作者： Daniele Caldana Artur Cordeiro João Pedro Souza Ricardo B. Sousa Paulo M. Rebelo António Joaquim Silva Manuel F. Silva CRIIS - Centre for Robotics in Industry and Intelligent Systems INESC TEC - Institute for Systems and Computer Engineering Technology and Science Portugal Faculty of Engineering University of Porto (FEUP) Portugal School of Science and Technology University of Trás-os-Montes e Alto Douro (UTAD) Portugal Seúibal Industrial Complex The Navigator Company Portugal ISEP Polytechnic of Porto Portugal

ISBN: (数字)9798350376364

ISBN: (纸本)9798350376371

The high level of precision and consistency required for pallet detection in industrial environments and logistics tasks is a critical challenge that has been the subject of extensive research. This paper proposes a system for detecting pallets and its pockets using the You Only Look Once (YOLO) v8 Open Neural Network Exchange (ONNX) model, followed by the segmentation of the pallet surface. On the basis of the system a pipeline built on the ROS Action Server whose structure promotes modularity and ease of implementation of heuristics. Additionally, is presented a comparison between the YOLOv5 and YOLOv8 models in the detection task, trained with a customised dataset from a factory environment. The results demonstrate that the pipeline can consistently perform pallet and pocket detection, even when tested in the laboratory and with successive 3D pallet segmentation. When comparing the models, YOLOv8 achieved higher average metric values, with YOLOv8m providing better detection performance in the laboratory setting.

关键词： YOLO Measurement Three-dimensional displays Pipelines Neural networks Production facilities Servers Pallets Robots Logistics