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Modelling and control of a Flexible Floating Boom: First Approach

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IFAC-PapersOnLine 2017年第1期50卷 13108-13113页

作者： Gapingsi, G.E. Korbas, R. Santos, M. Computer Architecture and Automatic Control Department Computer Science Faculty Complutense University of Madrid C/ Profesor García Santesmases 9 Madrid28040 Spain

Floating booms are useful tools in the marine world, especially for marine demarcation where some kind of contamination of sea, ocean or coastal water is present. In this work we have developed a mathematical model for a flexible floating boom which is hooked on two boats (unmanned surface vehicles). It is meant to be used for oil spill containment in marine areas. In order to simplify the model and to make possible its computer simulation, we have adopted a quasi-static approximation where we assume that the inertial forces are small compared to the drag forces applied to the boom. The simulation of this mathematical model has allowed the analysis of the behavior of the floating boom. Based on this knowledge, we have designed a control system which allows us to maintain the flexible floating boom in a specific configuration by controlling its shape. For that purpose, the control approach deals with the speed of the two ends of the floating boom. The results obtained with the implemented control system are encouraging, considering the model is a simplified discrete one and the control effort is reasonable. © 2017

关键词： Marine pollution control systems Drag Knowledge based systems Models Oil spills Unmanned surface vehicles control approach Floating boom Inertial forces Knowledge based control Modelling and controls Quasistatic approximations Simulation Spill containment

automatic detection of vehicles in outdoor parking lots from zenith perspective using neural networks

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Automatic detection of vehicles in outdoor parking lots from...

2020 Summer computer Simulation Conference, SCSC 2020, Held at the 2020 Summer Simulation Multi-Conference, SummerSim 2020

作者： García, Juan Manuel Carrera Piorno, Joaquín Recas Mata-Garcia, María Guijarro Department of Computer Architecture and Automatic Control Faculty of Computer Science Universidad Complutense de Madrid Spain

ISBN: (纸本)9781713819462

Nowadays there are a variety of methods to assist parking users in finding free sites in parking lots. However, there is no automatic system that takes into account the size of the car looking for a space or whether the cars adjacent to the free spaces are correctly parked. This paper presents a new method for detecting and calculating the area of vehicles in images taken from a zenith plane using computer vision and machine learning techniques that will help to create a vehicle-oriented search algorithm dedicated to finding the optimal spaces for vehicles entering an outdoor parking lot based on its characteristics. Results with scaled-down and real vehicles show that this new method can detect the area of the vehicles in an image with an average accuracy of 97.98%. ©2020 Society for Modeling & Simulation International (SCS)

关键词： Vehicles

Distributed formation maneuver control by manipulating the complex Laplacian

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arXiv 2020年

作者： de Marina, Hector Garcia Department of Computer Architecture Automatic Control Faculty of Physics Universidad Complutense Madrid Spain

This paper proposes a novel maneuvering technique for the complex-Laplacian-based formation control. We show how to modify the original weights that build the Laplacian such that a designed steady-state motion of the desired shape emerges from the local interactions among the agents. These collective motions can be exploited to solve problems such as the shaped consensus (the rendezvous with a particular shape), the enclosing of a target, or translations with controlled speed and heading to assist mobile robots in area coverage, escorting, and traveling missions, respectively. The designed steady-state collective motions correspond to rotations around the centroid, translations, and scalings of a reference shape. The proposed modification of the weights relocates one of the Laplacian's zero eigenvalues while preserving its associated eigenvector that constructs the desired shape. For example, such relocation on the imaginary or real axis induces rotational and scaling motions, respectively. We will show how to satisfy a sufficient condition to guarantee the global convergence to the desired shape and motions. Finally, we provide simulations and comparisons with other maneuvering techniques. Copyright © 2020, The Authors. All rights reserved.

关键词： Laplace transforms

Maneuvering and robustness issues in undirected displacement-consensus-based formation control

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arXiv 2020年

作者： de Marina, Hector Garcia Department of Computer Architecture and Automatic Control at the Faculty of Physics Universidad Complutense de Madrid Spain

n this paper, we first propose a novel maneuvering technique compatible with displacement-consensus-based formation controllers. We show that the formation can be translated with an arbitrary velocity by modifying the weights in the consensus Laplacian matrix. In fact, we demonstrate that the displacement-consensus-based formation control is a particular case of our more general method. We then uncover robustness issues with undesired steady-state motions and resultant distorted shapes in undirected displacement-consensus-based formation control. In particular, these issues are triggered when neighboring agents mismeasure their relative positions, e.g., their onboard sensors are misaligned and have different scale factors. We will show that if all the sensing is close to perfect but different among the agents, then the stability of the system is compromised. Explicit expressions for the eventual non-desired velocity and shape’s distortion are given as functions of the scale factors and misalignments for formations based on tree graphs. Copyright © 2020, The Authors. All rights reserved.

关键词： System stability

Comparison of black box implementations of two algorithms of processing of NMR spectra, Gaussian mixture model and singular value decomposition 8

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Comparison of black box implementations of two algorithms of...

8th International Conference on Bio-Inspired Systems and Signal Processing, BIOSIGNALS 2015

作者： Staniszewski, M. Binczyk, F. Skorupa, A. Boguszewicz, L. Sokol, M. Polanska, J. Polanski, A. Silesian University of Technology Faculty of Automatic Control Electronics and Computer Science Institute of Informatics Akademicka 16 Gliwice Poland Silesian University of Technology Faculty of Automatic Control Electronics and Computer Science Institute of Automatic Control Akademicka 16 Gliwice Poland Maria Skodowska-Curie Memorial Cancer Center Institute of Oncology Gliwice Branch Department of Medical Physics ul. Wybrzeze Armii Krajowej Gliwice Poland

ISBN: (纸本)9789897580697

Analysis of NMR spectra is a multi-stage computational process performed with the use of appropriately chosen sequence of algorithms. Initial stages of this process, called pre-processing, including filtering, baseline correction, phase correction and removal of unwanted components, are aimed at improving the quality of NMR spectral signal by rejection of noise, removing unnecessary spectral components and irregularities. After pre-processing the basic operations on NMR spectra are aimed at estimation of levels of certain metabolites by analysis of appropriate structural properties of NMR spectral signals. In this paper authors present design and implementation of two signals modelling methods. The first one is based on singular value decomposition of the induction decay signal. The second is done with use of mixture model constructed for frequency spectrum. Authors present all assumption that need to be satisfied and processing steps that must be performed before final analysis. The methods studied in the paper are implemented under the black-box assumption;i.e., prior knowledge of parameters of metabolites in the spectra is not used. As a second part of the project authors present a comparison of obtained result with popular modelling techniques and software LCmodel and Tarquin, based on experimental phantom dataset. Comparisons between different methods are based on the commonly used quality indexes, mean squared errors corresponding to levels of detected metabolites and specificities and sensitivities of the process of detection of metabolites. Using the presented comparisons we authors are able to characterize advantages and drawbacks of the studied approaches.

关键词： Metabolites

Singularity-free guiding vector field for robot navigation

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arXiv 2020年

作者： Yao, Weijia de Marina, Héctor Garcia Lin, Bohuan Cao, Ming University of Groningen Netherlands The Department of Computer Architecture and Automatic Control The Faculty of Physics Universidad Complutense de Madrid Madrid28040 Spain

In robot navigation tasks, such as UAV highway traffic monitoring, it is important for a mobile robot to follow a specified desired path. However, most of the existing path-following navigation algorithms cannot guarantee global convergence to desired paths or enable following self-intersected desired paths due to the existence of singular points where navigation algorithms return unreliable or even no solutions. One typical example arises in vector-field guided path-following (VF-PF) navigation algorithms. These algorithms are based on a vector field, and the singular points are exactly where the vector field diminishes. Conventional VF-PF algorithms generate a vector field of the same dimensions as those of the space where the desired path lives. In this paper, we show that it is mathematically impossible for conventional VF-PF algorithms to achieve global convergence to desired paths that are self-intersected or even just simple closed (precisely, homeomorphic to the unit circle). Motivated by this new impossibility result, we propose a novel method to transform self-intersected or simple closed desired paths to non-self-intersected and unbounded (precisely, homeomorphic to the real line) counterparts in a higher-dimensional space. Corresponding to this new desired path, we construct a singularity-free guiding vector field on a higher-dimensional space. The integral curves of this new guiding vector field is thus exploited to enable global convergence to the higher-dimensional desired path, and therefore the projection of the integral curves on a lower-dimensional subspace converge to the physical (lower-dimensional) desired path. Rigorous theoretical analysis is carried out for the theoretical results using dynamical systems theory. In addition, we show both by theoretical analysis and numerical simulations that our proposed method is an extension combining conventional VF-PF algorithms and trajectory tracking algorithms. Finally, to show the practical value of

关键词： Mobile robots

Is the identification of SNP-miRNA interactions supporting the prediction of human lymphocyte transcriptional radiation responses? 6

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Is the identification of SNP-miRNA interactions supporting t...

6th International Conference on Bioinformatics Models, Methods and Algorithms, BIOINFORMATICS 2015

作者： Dolbniak, Marzena Zyla, Joanna Kabacik, Sylwia Manning, Grainne Badie, Christophe Alsbeih, Ghazi Polanska, Joanna Institute of Automatic Control Faculty of Automatic Control Electronic and Computer Science Silesian University of Technology Akademicka 16 Gliwice Poland Cancer Genetics and Cytogenetics Group Biological Effects Department Centre for Radiation Chemical and Environmental Hazards Public Health England DidcotOX11 ORQ United Kingdom Radiation Biology Section Biomedical Physics Dept. King Faisal Specialist Hospital and Research Centre Riyadh11211 Saudi Arabia

ISBN: (纸本)9789897580703

Genome-Wide Association Studies (GWAS) are of great importance in identifying the genetic variants associated with traits/diseases. Due to the high number of candidate SNPs some filtering techniques are necessary to be applied. The aim of the study was to develop the comprehensive approach allowing for detailed analysis of both SNP-gene and SNP-miRNA-gene relations. We elaborated and optimized the novel signal analysis pipeline improving significantly the results of the analysis on genotype-phenotype interplay. Direct links between genotype results and gene expression levels were enriched by detailed analysis of SNP-miRNA-gene interactions at both mature miRNA structure/seed region and target binding site level. The proposed technique was applied to the data on lymphocyte radiation response and increased by almost 100% number of potential functional SNPs.

关键词： Gene expression

Angle-Constrained Formation control for Circular Mobile Robots

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arXiv 2020年

作者： Chan, Nelson P.K. Jayawardhana, Bayu de Marina, Hector Garcia Engineering and Technology Institute Groningen University of Groningen Nijenborgh 4 Groningen9747AG Netherlands Department of Computer Architecture and Automatic Control at the Faculty of Physics Universidad Complutense de Madrid Madrid28040 Spain

— In this letter, we investigate the formation control problem of mobile robots moving in the plane where, instead of assuming robots to be simple points, each robot is assumed to have the form of a disk with equal radius. Based on interior angle measurements of the neighboring robots’ disk, which can be obtained from low-cost vision sensors, we propose a gradient-based distributed control law and show the exponential convergence property of the associated error system. By construction, the proposed control law has the appealing property of ensuring collision avoidance between neighboring robots. We also present simulation results for a team of four circular mobile robots forming a rectangular *** Codes 34H05, 70E60, 93C10, 93C85 Copyright © 2020, The Authors. All rights reserved.

关键词： Mobile robots

Stability analysis of gradient-based distributed formation control with heterogeneous sensing mechanism: Two and three robot case

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arXiv 2020年

This paper focuses on the stability analysis of a formation shape displayed by a team of mobile robots that uses heterogeneous sensing mechanism. Depending on the convenience and reliability of the local information, each robot utilizes the popular gradient-based control law which, in this paper, is either the distance-based or the bearing-only formation control. For the two and three robot case, we show that the use of heterogeneous gradient-based control laws can give rise to an undesired invariant set where a distorted formation shape is moving at a constant velocity. The (in)stability of such an invariant set is dependent on the specified distance and bearing constraints. For the two robot case, we prove almost global stability of the desired equilibrium set while for the three robot case, we guarantee local asymptotic stability for the correct formation shape. We also derive conditions for the three robot case in which the undesired invariant set is locally attractive. Numerical simulations are presented for illustrating the theoretical results in the three robot *** Codes 34H05, 70E60, 93C10, 93C85 © 2020, CC-BY-NC-SA.

关键词： control theory