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arXiv 2020年

作者： Chong, Michelle S. Sandberg, Henrik Hespanha, João P. Control Systems Technology section Department of Mechanical Engineering Eindhoven University of Technology Netherlands Division of Decision and Control Systems KTH Royal Institute of Techonology Sweden Electrical and Computer Engineering Department University of California Santa Barbara United States

The state estimation of continuous-time nonlinear systems in which a subset of sensor outputs can be maliciously controlled through injecting a potentially unbounded additive signal is considered in this paper. Analogous to our earlier work for continuous-time linear systems in [1], we term the convergence of the estimates to the true states in the presence of sensor attacks as ‘observability under M attacks’, where M refers to the number of sensors which the attacker has access to. Unlike the linear case, we only provide a sufficient condition such that a nonlinear system is observable under M attacks. The condition requires the existence of asymptotic observers which are robust with respect to the attack signals in an input-to-state stable sense. We show that an algorithm to choose a compatible state estimate from the state estimates generated by the bank of observers achieves asymptotic state reconstruction. We also provide a constructive method for a class of nonlinear systems to design state observers which have the desirable robustness property. The relevance of this study is illustrated on monitoring the safe operation of a power distribution network. Copyright © 2020, The Authors. All rights reserved.

关键词： State estimation

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control of multi storey building structures with a new passive vibration control system combining base isolation with KDamper 7

Control of multi storey building structures with a new passi...

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7th International Conference on Computational Methods in Structural Dynamics and Earthquake engineering, COMPDYN 2019

作者： Kapasakalis, K.A. Antoniadis, I.A. Sapountzakis, E.J. Institute of Structural Analysis Antiseismic Reasearch School of Civil Engineering National Technical University of Athens Zografou Campus AthensGR-157 80 Greece Mechanical Design and Control Systems Section Mechanical Engineering Department National Technical University of Athens Zografou Campus AthensGR-157 80 Greece

ISBN: (纸本)9786188284456

Contemporary seismic isolation systems for building structures provide drastic reduction to the structure’s interstorey drifts and absolute accelerations. However, their major drawback is the large increase of the base displacement. Due to the high equivalent damping ratio, the novel KDamper passive vibration isolation and damping concept can provide an alternative approach for seismic protection. The KDamper is based on the optimal combination of appropriate stiffness elements, which include a negative stiffness element. The main advantage of the KDamper over other similar concepts including negative stiffness elements, is that no reduction in the overall stiffness of the system is required. This paper considers the application of a KDamper system to 3 storey concrete building structure. A dynamic system consisting from a simplified flexible structure model and KDamper devices is considered and is subjected to artificial accelerograms designed to match the EC response spectra. The KDamper is designed to higher frequencies compared to the isolated system with seismic isolation bearings, exploiting the extraordinary damping properties it offers. A comparison with a base isolated structure using Lead Rubber Bearings designed to greatly increase the fundamental period of the system (2.0-2.5 sec), confirms that KDamper base seismic absorption designs can provide great reduction to the interstorey drifts and absolute accelerations reducing at the same time the base displacement. © 2019 The authors.

关键词： Damping

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Computational analysis of metamaterials - an initial study

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Procedia Structural Integrity 2020年 25卷 172-179页

作者： P.N. Lymperopoulos E.E. Theotokoglou I.A. Antoniadis School of Applied Mathematical and Physical Sciences Department of Mechanics Laboratory of Testing and Materials National Technical University of Athens Zographou Campus Theocaris Bld GR-157 73 Athens Greece School of Mechanical Engineering Section of Mechanical Design & Automatic Control National Technical University of Athens Zographou Campus E Bld GR-157 73 Athens Greece

The seismic protection of buildings is a key part of the design of modern buildings. The use of existing seismic wave absorption devices are experiencing ageing problems over the years. For this reason, various alternative configurations, behaving as isolators have been proposed, including the use of metamaterials type of pentamodes. The aim of this work is to study the pentamodes regarding their use in various applications and particularly for the anti seismic design. Therefore, at first, an analytical approach of metamaterials, in static problems is presented. Results are then presented through the use of finite elements for various types of boundary conditions and for three different materials used in metamaterials systems. From our analysis, it can be concluded the optimum dimensions of the pentamode rod in order to have similar behaviour with isolators. Moreover, the pentamodes configuration which are made with metallic materials result that their use should be applied in the seismic protection design and aircraft structures, while the pentamodes which are manufactured from polymers are preferable to be used in applications of biomechanics.

关键词： Metamaterials Pentamode Finite Elements Analysis Composite Materials Biomechanics

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mechanical Analysis and Performance Optimization for the Lunar Rover’s Vane-Telescopic Walking Wheel

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engineering 2020年第8期6卷 936-943页

作者： Lu Yang Bowen Cai Ronghui Zhang Kening Li Zixian Zhang Jiehao Lei Baichao Chen Rongben Wang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin 300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin 300384China Guangdong Key Laboratory of Intelligent Transportation System School of Intelligent Systems EngineeringSun Yat-sen UniversityGuangzhou 510275China College of Transportation Jilin UniversityChangchun 130025China Department of Mechanical Science and Engineering Tokyo Institute of TechnologyTokyo 152-8550Japan Armour College of Engineering Illinois Institute of TechnologyChicagoIL 60616USA China Academy of Space Technology Beijing 100029China

It is well-known that optimizing the wheel system of lunar rovers is ***,this is a difficult task due to the complex terrain of the moon and limited resources onboard lunar *** this study,an experimental prototype was set up to analyze the existing mechanical design of a lunar rover and improve its ***,a new vane-telescopic walking wheel was proposed for the lunar rover with a positive and negative quadrangle suspension,considering the complex terrain of the ***,the performance was optimized under the limitations of preserving the slope passage and minimizing power *** was achieved via analysis of the wheel force during ***,the effectiveness of the proposed method was demonstrated by several simulation *** newly designed wheel can protrude on demand and reduce energy consumption;it can be used as a reference for lunar rover development engineering in China.

关键词： Intelligent vehicle Vane-telescopic walking wheel Performance optimization Vane spring Lunar rover

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Opportunities and challenges for monitoring terrestrial biodiversity in the robotics age

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Nature Ecology and Evolution 2025年第6期9卷 1031-1042页

作者： Pringle, Stephen Dallimer, Martin Goddard, Mark A. Le Goff, Léni K. Hart, Emma Langdale, Simon J. Fisher, Jessica C. Abad, Sara-Adela Ancrenaz, Marc Angeoletto, Fabio Auat Cheein, Fernando Austen, Gail E. Bailey, Joseph J. Baldock, Katherine C. R. Banin, Lindsay F. Banks-Leite, Cristina Barau, Aliyu S. Bashyal, Reshu Bates, Adam J. Bicknell, Jake E. Bielby, Jon Bosilj, Petra Bush, Emma R. Butler, Simon J. Carpenter, Dan Clements, Christopher F. Cully, Antoine Davies, Kendi F. Deere, Nicolas J. Dodd, Michael Drinkwater, Rosie Driscoll, Don A. Dutilleux, Guillaume Dyrmann, Mads Edwards, David P. Farhadinia, Mohammad S. Faruk, Aisyah Field, Richard Fletcher, Robert J. Foster, Chris W. Fox, Richard Francksen, Richard M. Franco, Aldina M. A. Gainsbury, Alison M. Gardner, Charlie J. Giorgi, Ioanna Griffiths, Richard A. Hamaza, Salua Hanheide, Marc Hayward, Matt W. Hedblom, Marcus Helgason, Thorunn Heon, Sui P. Hughes, Kevin A. Hunt, Edmund R. Ingram, Daniel J. Jackson-Mills, George Jowett, Kelly Keitt, Timothy H. Kloepper, Laura N. Kramer-Schadt, Stephanie Labisko, Jim Labrosse, Frédéric Lawson, Jenna Lecomte, Nicolas de Lima, Ricardo F. Littlewood, Nick A. Marshall, Harry H. Masala, Giovanni L. Maskell, Lindsay C. Matechou, Eleni Mazzolai, Barbara McConnell, Alistair Melbourne, Brett A. Miriyev, Aslan Nana, Eric Djomo Ossola, Alessandro Papworth, Sarah Parr, Catherine L. Payo-Payo, Ana Perry, Gad Pettorelli, Nathalie Pillay, Rajeev Potts, Simon G. Prendergast-Miller, Miranda T. Qie, Lan Rolley-Parnell, Persie Rossiter, Stephen J. Rowcliffe, Marcus Rumble, Heather Sadler, Jon P. Sandom, Christopher J. Sanyal, Asiem Schrodt, Franziska Sethi, Sarab S. Shabrani, Adi Siddall, Robert Smith, Simón C. Snep, Robbert P. H. Soulsbury, Carl D. Stanley, Margaret C. Stephens, Philip A. Stephenson, P.J. Struebig, Matthew J. Studley, Matthew Svátek, Martin Tang, Gilbert Taylor, Nicholas K. Umbers, Kate D. L. Ward, Robert J. White, Patrick J. C. Whittingham, Mark J. Wich, Serge Williams, Christopher D. Yakubu, Ibrahim B. Yoh, Natalie Durrell Institute of Conservation and Ecology (DICE) School of Natural Sciences University of Kent Canterbury United Kingdom Centre for Environmental Policy Imperial College London London United Kingdom Department of Geography and Environmental Sciences Northumbria University Newcastle upon Tyne United Kingdom School of Computing Engineering and the Built Environment Edinburgh Napier University Edinburgh United Kingdom Synthotech Ltd Milner Court Hornbeam Square Harrogate United Kingdom Mechanical Engineering Department University College London London United Kingdom HUTAN SWD Kota Kinabalu Malaysia Programa de Pós-Graduação em Gestão e Tecnologia Ambiental da Universidade Federal de Rondonópolis Rondonópolis Brazil Department of Engineering Harper Adams University Newport United Kingdom Applied Ecology Research Group School of Life Sciences Anglia Ruskin University Cambridge United Kingdom Centre for Ecology and Hydrology Penicuik United Kingdom Department of Life Sciences Imperial College London Silwood Park Campus Ascot United Kingdom Department of Urban and Regional Planning Faculty of Earth and Environmental Sciences Bayero University Kano Nigeria Greenhood Nepal Kathmandu Nepal Animal Rural & Environmental Sciences Nottingham Trent University Nottinghamshire United Kingdom School of Biological and Environmental Sciences Liverpool John Moores University Liverpool United Kingdom Lincoln Centre for Autonomous Systems University of Lincoln Lincoln United Kingdom Royal Botanic Garden Edinburgh Edinburgh United Kingdom School of Biological Sciences University of East Anglia Norwich Research Park Norwich United Kingdom Digital Ecology Limited Bristol United Kingdom School of Biological Sciences University of Bristol Bristol United Kingdom Department of Computing Imperial College London London United Kingdom Department of Ecology and Evolutionary Biology University of Colorado Boulder CO United States Faculty of Science Technology Engineering

With biodiversity loss escalating globally, a step change is needed in our capacity to accurately monitor species populations across ecosystems. Robotic and autonomous systems (RAS) offer technological solutions that may substantially advance terrestrial biodiversity monitoring, but this potential is yet to be considered systematically. We used a modified Delphi technique to synthesize knowledge from 98 biodiversity experts and 31 RAS experts, who identified the major methodological barriers that currently hinder monitoring, and explored the opportunities and challenges that RAS offer in overcoming these barriers. Biodiversity experts identified four barrier categories: site access, species and individual identification, data handling and storage, and power and network availability. Robotics experts highlighted technologies that could overcome these barriers and identified the developments needed to facilitate RAS-based autonomous biodiversity monitoring. Some existing RAS could be optimized relatively easily to survey species but would require development to be suitable for monitoring of more ‘difficult’ taxa and robust enough to work under uncontrolled conditions within ecosystems. Other nascent technologies (for instance, new sensors and biodegradable robots) need accelerated research. Overall, it was felt that RAS could lead to major progress in monitoring of terrestrial biodiversity by supplementing rather than supplanting existing methods. Transdisciplinarity needs to be fostered between biodiversity and RAS experts so that future ideas and technologies can be codeveloped effectively. © The Author(s) 2025.

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Techno-economic impact assessment of recycled gypsum usage in plasterboard manufacturing

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Journal of Remanufacturing 2019年第3期9卷 141-167页

作者： Papailiopoulou, N. Grigoropoulou, H. Founti, M. Chemical Process Engineering Laboratory Department of Process Analysis and Plant Design School of Chemical Engineering National Technical University of Athens Heroon Polytechniou 9 Polytechnioupoli Zografou Athens 15780 Greece Laboratory of Heterogeneous Mixtures and Combustion Systems Thermal Engineering Section School of Mechanical Engineering National Technical University of Athens Heroon Polytechniou 9 Polytechnioupoli Zografou Athens 15780 Greece

Recycled gypsum derived from post-consumer sources is a promising resource that can be reincorporated in the production chain, offering opportunities to decrease manufacturing costs given its significantly lower price compared to conventional gypsum. The systematic usage of post-consumer recycled gypsum is a relatively new practice in the plasterboard industry and there is lack of extensive literature references on the potential effects on the manufacturig process, since the available related studies are limited to more holistic approaches. The current work is, to our knowledge, the first study to assess the practice of gypsum recycling from an economical and technical point of view within the boundaries of the plasterboard manufacturing process. The paper provides a detailed techno-economic impact assessment of the usage of recycled gypsum up to 30% by weight in feedstock in the manufacturing of Type A plasterboard, based on data collected from full-scale industrial production trials carried out in five representative European plants located in four different countries. The potential impacts are analyzed in relation to each affected process parameter. A series of options for process adjustments, modifications and corrective measures in order to amortize the effects on product quality and/or cost are also reported. The analysis indicates high dependence of the cost impacts on process-specific characteristics. A limited reduction of 0.6% in the average total manufacturing cost per m² of plasterboard was calculated, which can be associated to the considerable decrease, by 9.5%, of raw material costs. The latter fully compensates the increases to other process costs, and mainly to chemical additives which increased by 8%. The overall analysis allows quantification of the process parameters and costs that are affected when the percentage of recycled gypsum incorporated in plasterboard production is significantly increased. The results and the methodology prop

关键词： Plasterboard manufacturing costs Plasterboard manufacturing process Recycled gypsum Techno-economic impact

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Integrated Production and Maintenance control Policies for Failure-prone Manufacturing systems Producing Perishable Products

Research Square

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Research Square 2021年

作者： Kaddachi, Rawia Gharbi, Ali Kenne, Jean-Pierre Systems Engineering Department École de Technologie Supérieure Production System Design and Control Laboratory Université du Québec 1100 Notre-Dame Street West MontrealQCH3C 1K3 Canada Mechanical Engineering Department École de Technologie Supérieure Laboratory of Integrated Production Technologies Université du Québec 1100 Notre-Dame Street West MontrealQCH3C 1K3 Canada

The problem of integrated production and maintenance control of unreliable manufacturing systems evolving in a stochastic and dynamic environment is studied in this paper. The considered system is subject to degradation and the produced products are perishable with random shelf-lives. The literature of operations management for perishable products reports a correlation between the shelf-life of the product and the machine degradation. In fact, the latter results in shelf-lives reduction. Ignoring this correlation effect may result in inaccurate values of the shelf-lives and inefficient control policies. The objective of this paper is to develop a joint production and maintenance control policy that minimizes the total cost composed of backlog, inventory holding, disposal and maintenance costs. The proposed parametrized joint control policy combines a multi hedging point policy and an age-based preventive maintenance policy. The optimization of the parameters of the proposed joint control policy is obtained using a simulation-based optimization approach and sensitivity analyses are provided to confirm its robustness. The obtained results show that the correlation between machine degradation and shelf-life reduction has a major influence on the control parameters and that preventive maintenance interventions can lead to increasing the shelf-life of products and minimizing the total cost. The proposed joint control policy is then compared to three other polices for a wide range of system and cost data. The obtained results show that the proposed joint control policy outperforms the other polices in terms of total incurred costs. © 2021, CC BY.

关键词： Preventive maintenance

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Research on Heat Transfer in High Temperature Garments 6

Research on Heat Transfer in High Temperature Garments

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2019 6th International Conference on Advanced Composite Materials and Manufacturing engineering, ACMME 2019

作者： Wan, Yi-Fei Lin, Peng-Yi Li, Hao-Yi Dai, Chang-Ping Department of Mechanical Design Xi'an University of Technology No.5 Jinhua South Road Xi'an China Department of Information and Control Engineering Xi'an University of Technology No.5 Jinhua South Road Xi'an China Department of Engineering Management Changsha University of Science and Technology No. 960 Wanjiali South Road Yuhua District Section 2 Changsha China

This paper describes the Law of heat transfer between the layers of material and a method for determining the thickness of layers of material parameters of a high temperature protective clothing. Three important choice of protective clothing material and the air gap layer as the research object, based on the Fourier law and the energy conservation law to establish second order partial differential equation, solving the Crank-Nicolson method by second order partial differential equation, derived temperature, time, the relationship between the thickness. Finally, in the case where the heat transfer ANSYS software simulation under the above conditions, a comparative analysis with calculated transfer law, the error is 1.2%, higher accuracy results. © Published under licence by IOP Publishing Ltd.

关键词： Protective clothing

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Supervisory control of Timed Discrete-Event systems Subject to Communication Delays and Non-FIFO Observations

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IFAC-PapersOnLine 2018年第7期51卷 456-463页

作者： Rashidinejad, Aida Reniers, Michel Feng, Lei Control Systems Technology Group Department of Mechanical Engineering Eindhoven University of Technology P.O.Box 513 EindhovenMB5600 Netherlands Department of Machine Design KTH Royal Institute of Technology Stockholm100 44 Sweden

Conventional supervisory control synthesis techniques are not adequate anymore when a network between the plant and the supervisor introduces communication delays. This paper presents a method to synthesize a networked supervisor handling delays in both observation and control channels. To deal with the problem of delayed observations, we propose an automaton modeling the behaviour of the plant observed by a supervisor through a network, called observed plant. In this automaton, events observed by a supervisor are delayed from those occurring in the plant. Moreover, since observation channels are considered not to have the first in first out (FIFO) characteristic, events may not be necessarily observed in the same order as they occurred within the plant. A safe, observable, controllable and nonblocking supervisor is synthesized for the observed plant by means of an adapted synthesis algorithm for timed discrete-event systems (TDES). By enabling the achieved supervisor to predict the effects of control delays, it will be further transformed to a networked supervisor. The networked supervisor makes decisions ahead of time to ensure that the commands will be applied on the right (plant) state. © 2018

关键词： Supervisory personnel Accident prevention Discrete event simulation Discrete time control systems Synthesis (chemical) Communication delays Delayed observation Nonblocking supervisors nonblockingness Supervisory control Supervisory control synthesis Synthesis algorithms Timed discrete event systems

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Fully enclosed multi-axis inertial reaction mechanisms for wave energy conversion

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Journal of Ocean engineering and Science 2017年第1期2卷 5-17页

作者： I.A.Antoniadis V.Georgoutsos A.Paradeisiotis Mechanical Design and Control Systems Section Mechanical Engineering DepartmentNational Technical University of AthensHeroon Polytechniou 9Zografou 15780Greece

This paper introduces a novel concept for wave energy conversion,using fully enclosed appropriate internal body configurations,which provide inertial reaction against the motion of an external *** this way,reliability,robustness and survivability under extreme weather conditions-a fundamental prerequisite for wave energy converters-can be *** under the excitation of the waves,the external vessel is subjected to a simultaneous surge and pitch motion in all directions,ensuring maximum wave energy capture in comparison to other wave energy converters like point heave *** internal body is suspended from the external vessel body in such an appropriate geometrical configuration,that a symmetric four-bar mechanism is essentially *** main advantage of this suspension geometry is that a linear trajectory results for the centre of the mass of the suspended body with respect to the external vessel,enabling the introduction of a quite simple form of a Power Take Off(PTO)***,because of this simplicity and symmetry of the suspension geometry and of the PTO mechanism,the fundamental restrictions of other linear,pendulum or gyroscopic variants on inertial reacting bodies are significantly removed.

关键词： Waves Energy Inertial Pendulum Platforms Offshore

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