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A Finite -Time Robust control for a Manipulator with Output Constraints and Unknown control Directions 5

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A Finite -Time Robust Control for a Manipulator with Output ...

5th International Conference on Green technology and Sustainable Development, GTSD 2020

作者： Tran, Duc-Thien Tran, Manh-Son Hiep, Nguyen Van Ho Chi Minh City University of Technology and Education Faculty of Electrical and Electronic Engineering Department of Automatic Control Ho Chi Minh City Viet Nam Ho Chi Minh City University of Technology and Education Faculty of Electrical and Electronic Engineering Department of Electronics-Biomedical Engineering Ho Chi Minh City Viet Nam

ISBN: (纸本)9781728199825

This paper presents a finite time robust control for a robotic manipulator regardless of the time-varying output constraints and unknown control direction. First, a transformation technique is investigated to handle the output constraints by converting a constrained system into a free constrained system. When the stability of the free constrained system is guaranteed, the constrained system will overcome the violation of system output. Next, the backstepping control is developed on the unconstrained system with fractional order term to improve the accuracy and transient time of the output responses. Furthermore, a Nussbaum gain function is integrated into the control algorithm to address the problem of unknown control direction. A numerical simulation is provided to confirm the superiorities of the proposed control. © 2020 IEEE.

关键词： Robust control

New approach for analysing dynamical processes on the surface of photospheric vortex tubes

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arXiv 2022年

作者： Aljohani, Yasir Fedun, Viktor Ballai, Istvan Silva, Suzana S.A. Shelyag, Sergiy Verth, Gary Plasma Dynamics Group School of Mathematics and Statistics University of Sheffield Hicks Building Hounsfield Road SheffieldS3 7RH United Kingdom Department of Mathematics Jamoum University College Umm Al-Qura University Jamoum Makkah25375 Saudi Arabia Plasma Dynamics Group Department of Automatic Control and Systems Engineering University of Sheffield Mappin Street SheffieldS1 3JD United Kingdom School of Information Technology Deakin University Geelong Australia

The majority of studies on multi-scale vortex motions employ a two-dimensional geometry by using a variety of observational and numerical data. This approach limits the understanding the nature of physical processes responsible for vortex dynamics. Here we develop a new methodology to extract essential information from the boundary surface of vortex tubes. 3D high-resolution magnetoconvection MURaM numerical data has been used to analyse photospheric intergranular velocity vortices. The Lagrangian Averaged Vorticity Deviation (LAVD) technique was applied to define the centers of vortex structures and their boundary surfaces based on the advection of fluid elements. These surfaces were mapped onto a constructed envelope grid that allows the study of the key plasma parameters as functions of space and time. Quantities that help in understanding the dynamics of the plasma, e.g. Lorentz force, pressure force, plasma-β were also determined. Our results suggest that, while density and pressure have a rather global behaviour, the other physical quantities undergo local changes, with their magnitude and orientation changing in space and time. At the surface, the mixing in the horizontal direction is not efficient, leading to appearance of localized regions with higher/colder temperatures. In addition, the analysis of the MHD Poynting flux confirms that the majority of the energy is directed in the horizontal direction. Our findings also indicate that the pressure and magnetic forces that drive the dynamics of the plasma on vortex surfaces are unbalanced and therefore the vortices do not rotate as a rigid body. Copyright © 2022, The Authors. All rights reserved.

关键词： Vortex flow

Robustification of Continuous-Time ADMM against Communication Delays under Non-Strict Convexity: A Passivity-Based Approach

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SICE Journal of control, Measurement, and System Integration 2020年第6期13卷 299-305页

作者： Yamashita, Shunya Li, Mengmou Hatanaka, Takeshi Department of Systems and Control Engineering Tokyo Institute of Technology Japan Department of Electrical and Electronic Engineering the University of Hong Kong China

In this paper, we address a class of distributed optimization problems with non-strictly convex cost functions in the presence of communication delays between an agent and a coordinator. To this end, we focus on a continuous-time optimization algorithm that mirrors the alternating direction method of multipliers. We first redesign the algorithm so that the dynamics ensures smoothness and a sub-block for primal optimization includes stable zeros. It is then revealed that the algorithm is composed of feedback interconnection of passive systems. We next robustify the algorithm against communication delays by applying the so-called scattering transformation. The smoothness of the dynamics allows one to use the invariance principle for delay systems, and accordingly, the state trajectories are shown to converge to an optimal solution even without the strict convexity assumption. Finally, the presented method is demonstrated via simulation of an environmental-monitoring problem. © Taylor & Francis Group, LLC 2020.

关键词： Convex optimization

Port-Hamiltonian formulations of the incompressible Euler equations with a free surface

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arXiv 2023年

作者： Cheng, Xiaoyu Van der Vegt, J.J.W. Xu, Yan Zwart, H.J. School of Mathematics University of Science and Technology of China Anhui Hefei230026 China Department of Applied Mathematics Mathematics of Computational Science Group University of Twente P.O. Box 217 Enschede7500 AE Netherlands Department of Applied Mathematics Mathematics of Systems Theory Group University of Twente P.O. Box 217 Enschede7500 AE Netherlands Department of Mechanical Engineering Dynamics and Control Group Eindhoven University of Technology P.O. Box 513 Eindhoven5600 MB Netherlands

In this paper, we present port-Hamiltonian formulations of the incompressible Euler equations with a free surface governed by surface tension and gravity forces, modelling e.g. capillary and gravity waves and the evolution of droplets in air. Three sets of variables are considered, namely (v, Σ), (η, ∂, Σ) and (ω, ∂, Σ), with v the velocity, η the solenoidal velocity, ∂ a potential, ω the vorticity, and Σ the free surface, resulting in the incompressible Euler equations in primitive variables and the vorticity equation. First, the Hamiltonian formulation for the incompressible Euler equations in a domain with a free surface combined with a fixed boundary surface with a homogeneous boundary condition will be derived in the proper Sobolev spaces of differential forms. Next, these results will be extended to port-Hamiltonian formulations allowing inhomogeneous boundary conditions and a non-zero energy flow through the boundaries. Our main results are the construction and proof of Dirac structures in suitable Sobolev spaces of differential forms for each variable set, which provides the core of any port-Hamiltonian formulation. Finally, it is proven that the state dependent Dirac structures are related to Poisson brackets that are linear, skew-symmetric and satisfy the Jacobi *** Codes 35Q35, 35Q31 Copyright © 2023, The Authors. All rights reserved.

关键词： Vorticity

Unveiling Multivariate EEG Features: A Novel Approach to Enhancing ADHD Diagnosis Through Visual and Auditory Attention Tests

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Unveiling Multivariate EEG Features: A Novel Approach to Enh...

International Conference on Fuzzy Theory and it's Applications (iFUZZY)

作者： Zuo-Cian Fan Ro-Wei Lin Ching-Shu Tsai Wen-Jiun Chou Chia-Jung Li Zih-Jun Huang Bin-Yu Shih Liang-Jen Wang Li-Wei Ko Department of Biological Science & Technology Center for Intelligent Drug Systems and Smart Bio-Devices (IDS2B) College of Biological Science and Technology National Yang Ming Chiao Tung University Hsinchu Taiwan International Ph.D. Program in Interdisciplinary Neuroscience National Yang Ming Chiao Tung University Hsinchu Taiwan Department of Child and Adolescent Psychiatry Kaohsiung Chang Gung Memorial Hospit Department of Electronics and Electrical Engineering Institute of Electrical and Control Engineering National Yang Ming Chiao Tung University Hsinchu Taiwan

We sought to revolutionize the classification of Attention-Deficit/Hyperactivity Disorder (ADHD) by pioneering an innovative approach that seamlessly integrated auditory and visual tests with electroencephalogram (EEG) coherence analysis, forming the foundation for our Support Vector Machine (SVM) models. Our primary objective was to achieve precise differentiation between individuals with ADHD and those without, aiming to reshape the landscape of ADHD diagnosis and early intervention. We constructed an SVM model based on CATA coherence, incorporating a carefully selected set of 180 features, and another grounded in CPT coherence with 70 features. Astonishingly, our exploration uncovered that a model incorporating CATA's coherence and Power Spectral Density (PSD) as features achieved an astounding accuracy rate of 97.7%, using only half the number of features. This revelation hints at untapped potential for multivariate advancements in the realm of ADHD classification. The landscape of ADHD diagnosis and intervention is perpetually evolving, most notably with the FDA's approval of game therapy for ADHD. Leveraging the transformative power of our findings, we envision the development of user-friendly game therapies for in-home use, empowering both clinicians and parents alike. This marks a paradigm shift in the realm of ADHD intervention, offering objective, data-driven tools for the early management of ADHD. Gamified therapy not only enhances accessibility but also fosters engagement and compliance, all of which are pivotal in the long-term care of individuals with ADHD. In summary, our study represents a significant advancement in our comprehension and classification of ADHD. By fusing auditory and visual tests with EEG coherence analysis, fortified by state-of-the-art machine learning techniques, we have achieved an unprecedented level of accuracy in identifying individuals with ADHD. Our findings, aligned with the FDA-approved game therapy, offer a glimpse into a

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A Robust Fault Detection Method using a Zonotopic Kaucher Set-membership Approach

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IFAC-PapersOnLine 2018年第24期51卷 500-507页

作者： Schwab, Stefan Puig, Vicenç Hohmann, Soeren Institute of Control Systems Karlsruhe Institute of Technology Karlsruhe Germany Automatic Control Department Universitat Politècnica de Catalunya Barcelona Spain

This paper presents a robust fault detection method using a zonotopic Kaucher set-membership method. The fault detection approach is based on checking the consistency between the model and the data. Consistency is given if there is an intersection between the feasible parameter set and the nominal parameter set. To allow efficient computation the feasible set is approximated by a zonotope. Due to the usage of Kaucher interval arithmetic the results are mathematically guaranteed. The proposed approach is assessed using an illustrative application based on a well-known four-tank case study. The study shows that it is possible to detect even small errors in a noisy setting. © 2018

关键词： Fault detection

Investigation of the Nh3 Consumption and H2o/No Formation During the Oxidation of N-Heptane and Iso-Octane Blended with Ammonia

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SSRN

SSRN 2023年

作者： Zheng, Dao Peng, Zhimin He, Dong Zhang, Meng Li, Jidong Ding, Yanjun Du, Yanjun School of Control and Computer Engineering North China Electric Power University Beijing102206 China State Key Laboratory of Power Systems Department of Energy and Power Engineering Tsinghua University Beijing100084 China Advanced Propulsion Laboratory Department of Modern Mechanics University of Science and Technology of China Hefei230026 China University of Chinese Academy of Sciences School of Engineering Sciences Beijing100049 China Tsinghua University China

Adding highly active fuels with ammonia is a compromising way to increase the mixture's reactivity. However, there are very few studies blending ammonia with large hydrocarbons, such as n-heptane and isooctane. In this study, the NH3, NO, and H2O time-histories were simultaneously measured during the oxidation of ammonia/n-heptane and ammonia/isooctane mixtures (equivalence ratio Φ ~ 1.2) in a shock tube. For the ammonia/n-heptane mixture, a reduced kinetics model, the Wang 2023 model, shows the best predictions in terms of the mixture reactivity and the H2O production but underpredicts the NO plateau. For the ammonia/isooctane mixture, the CRECK_TPRF_Alcohols_NOx (CRECK) model is the only available kinetics model containing ammonia and isooctane mechanisms. The CRECK model captures the H2O plateau but underpredicts the ammonia/isooctane mixture reactivity and the NO plateau. Detailed analyses are conducted based on the Wang 2023 and CRECK models. Rate-of-production (ROP) analyses reveal that: the consumption or formation pathways of the three species in the two models are basically the same but the magnitudes of the ROPs are quite different, especially for the NO formation;the reaction of ethylene or propylene with NH2 radical in the Wang 2023 model also contributes significantly to the NH3 consumption but they are not considered in the CRECK model. Sensitivity analyses show that: H + O2 = O + OH is the most promoting reaction for both mixtures and models;however, several reactions show strong effects in one mixture while having little effect in another mixture, or even playing an opposite effect. After modifying or adding some key reactions, the Wang 2023 and CRECK models get significantly improved in predicting the species' time-history during the oxidation of the ammonia/n-heptane or ammonia/isooctane mixture. © 2023, The Authors. All rights reserved.

关键词： Shock tubes

Estimating asymptotic phase and amplitude functions of limit-cycle oscillators from time series data

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arXiv 2022年

作者： Namura, Norihisa Takata, Shohei Yamaguchi, Katsunori Kobayashi, Ryota Nakao, Hiroya Department of Systems and Control Engineering Tokyo Institute of Technology Tokyo152-8552 Japan Graduate School of Frontier Sciences The University of Tokyo Chiba277-8561 Japan Mathematics and Informatics Center The University of Tokyo Tokyo113-8656 Japan JST PRESTO Saitama332-0012 Japan

We propose a method for estimating the asymptotic phase and amplitude functions of limit-cycle oscillators using observed time series data without prior knowledge of their dynamical equations. The estimation is performed by polynomial regression and can be solved as a convex optimization problem. The validity of the proposed method is numerically illustrated by using two-dimensional limit-cycle oscillators as examples. As an application, we demonstrate data-driven fast entrainment with amplitude suppression using the optimal periodic input derived from the estimated phase and amplitude functions. © 2022, CC BY.

关键词： Convex optimization

Distributed design of deterministic discrete-time privacy preserving average consensus for multi-agent systems through network augmentation

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arXiv 2021年

作者： Ramos, Guilherme Pedro Aguiar, A. Kar, Soummya Pequito, Sérgio The Department of Electrical and Computer Engineering Faculty of Engineering University of Porto Portugal The Department of Electrical and Computer Engineering Carnegie Mellon University United States The Delft University of Technology The Delft Center for Systems and Control Netherlands

Average consensus protocols emerge with a central role in distributed systems and decision-making such as distributed information fusion, distributed optimization, distributed estimation, and control. A key advantage of these protocols is that agents exchange and reveal their state information only to their neighbors. Yet, it can raise privacy concerns in situations where the agents' states contain sensitive information. In this paper, we propose a novel (noiseless) privacy preserving distributed algorithms for multi-agent systems to reach an average consensus. The main idea of the algorithms is that each agent runs a (small) network with a crafted structure and dynamics to form a network of networks (i.e., the connection between the newly created networks and their interconnections respecting the initial network connections). Together with a re-weighting of the dynamic parameters dictating the inter-agent dynamics and the initial states, we show that it is possible to ensure that the value of each node converges to the consensus value of the original network. Furthermore, we show that, under mild assumptions, it is possible to craft the dynamics such that the design can be achieved in a distributed fashion. Finally, we illustrate the proposed algorithm with examples. Copyright © 2021, The Authors. All rights reserved.

关键词： Multi agent systems