his.sePublikasjoner
Endre søk
Begrens søket
12 51 - 80 of 80
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 51.
    Nilsson, Jonatan
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Planering och utvecklande av testplattform för tryckpulsation2019Independent thesis Basic level (degree of Bachelor), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Autotube är ett företag baserat i Varberg som utvecklar och producerar luft- och vätskelösningar främst inom bilindustrin. På senare tid har biltillverkarna skiftat till högre bränsletryck i bensindrivna förbränningsmotorer vilket har lett till att företagets produktutvecklingsavdelning saknar testutrustning för att utveckla nya produkter vilket i sin tur har lett till att företaget köpt tjänsten från extern leverantör. Kostnaderna och den bristande insynen i trycktester hos extern leverantör har lett Autotube att investera i ny utrustning och bedriva framtida tester i företagets lokaler. Ambitionen är att testanläggningen ska kunna genomföra tryckpulser och sprängprover både för produktutveckling och stickprov. Det övergripande syftet med examensarbetet är att programmera PLC logiken, designa HMI-panelen och skapa en elektriskt överförbar rapport efter genomfört testutförande.

    Under projektets progression visade studier och företagets empiriska kunskaper att resultatet från testanläggningen karakteriseras av tre nyckelparametrar; funktionsduglighet, realtidsövervakning och datahantering. Varje kategori har givetvis flera underkategorier som adderar värde till nyckelparametrarna.

    För funktionsduglighet krävs pålitlig hårdvara som klarar av att vara driftsatt under lång tid utan avbrott. Dock om ett avbrott från yttre faktorer skulle inträffa behöver testanläggningen programmeras för att spara data och undvika att testresultaten raderas. För att undvika irritation och handhavandefel bör användargränssnittet vara utformad efter målgruppens behov och mängden information bör begränsas.

    God realtidsövervakning ställer krav på lättåtkomlig information både vid testanläggningen och på distans vilket ökar möjligheten att läsa av testutförandes värden oberoende av vart användaren befinner sig. För att minska användarens arbetsbelastning bör varningssignaler som indikerar när testanläggningen inte utför önskvärt arbete användas.

    Datahantering bör ske automatiserat för att tillse att rätt data lagras och att den mänskliga faktorn kringgås. Flertalet rapporter under testutförandets förlopp är fördelaktigt för jämförelse av testutförandets olika skeden vilket ökar insikten om vad som skett när och möjliggör en djupare analys av testutförandet.

    Det genomförda arbetet har analyserat olika alternativ och använt litteratur relevant till nyckelparametrarna tillsammans med kontinuerlig återkoppling från företagets tekniker för att skapa mjukvaran till testanläggningen. Resultatet är en pålitlig anläggning med skräddarsydd realtidsövervakning och automatisk datahantering.

  • 52.
    Nordby, Johan
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Tholin, Mikael
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    TIDSSTUDIEANALYS AV MANUELL PRODUKTHANTERING VID I- OCH URLASTNING I PRODUKTIONSUTRUSTNINGAR: Produktionssystemutveckling enligt Chaku-Chaku/Hanedashi-principen2013Independent thesis Basic level (degree of Bachelor), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Projektarbetet är förlagt till Autoliv Sverige AB (Autoliv) i Vårgårda. Autoliv vill förbättra hanteringen av material i processflödena genom att höja tillgängligheten på maskinerna. Materialet hanteras omväxlande manuellt och maskinellt i processerna. Uppdraget var att ta fram ett eller flera konkreta förbättringsförslag som använder produktionstekniken Chaku-Chaku, även kallat Hanedashi, samt att dessa var tids- och kostnadseffektiva och utnyttjar redan befintlig utrustning.Arbetet avgränsades genom att bara inkludera de tre produktionsceller som kräver mest arbetstid av produktionspersonalen samt en nyligen uppstartad produktionscell. Vid förändring av en maskin påverkas dennas befintliga CE-märkning, varför en utredning om ny CE-märkning behöver genomföras. Arbetet kommer inte att behandla kostnader eller utredning för ommärkningen.För att kunna beräkna tidseffektiviseringen på processerna gjordes en tidsstudieanalys och av analysen gick det även att beräkna olika värden från produktionen som var av vikt för senare beräkning av kostnadsbesparingar. Fyra lösningsförslag togs fram och analyserades för tidseffektivitet. Utav dessa fyra valdes tre för beräkna kostnader och kostnadsbesparingar vid utökad tillverkning eller vid tillverkning av samma antal. Kraven var att produktionen vid utökad tillverkning skulle göra en årlig ökning av antalet produkter med minst 7%.Av de lösningsförslag som valdes för vidare analys gick det första ut på att förmontera en komponent till produkten på en separat plats istället för att montera den inne i en maskin, då detta ansågs vara ett problematiskt arbetsmoment. Förbättringen innehåller ett nytt föreslaget rörelseschema för operatören och en ny layout av produktionscellen. Det andra förslaget syftar till att när modulen har behandlats färdigt i en av stationerna i cellen, matas den automatiskt ur stationen och således görs tillgänglig för nästkommande modul. Det andra förslaget rekommenderas att kombineras med det första förslaget då de kan komplementera varandra i tidsbesparingar, då förslagen är på samma produktionscell. Det tredje förslaget gick ut på att en gripanordning lyfter undan modulen en bit för att kunna bearbetas av operatör samtidigt som efterföljande modul leds in i maskinen. Detta förslag skulle innebära att den väntan som uppstår vid arbetsutförande inuti eller utav maskinen vid två separata tillfällen kommer synkroniseras. Förbättringsförslagen beräknades resultera i besparad operatörskostnad vid tillverkning av samma antal enheter. Kalkyler gjordes för att visa lönsamheten för förslagen vid utökad tillverkning samt vid vilket antal tillverkade produkter som förslagen har nått break-even. Förslagen börjar betala av sig själva efter ca 700 tillverkade enheter vid vardera produktionscell och vidare även utöka produktionen med 7%.

  • 53.
    Potros, Bashar
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Framställning av mätmetod för att upptäcka defekta luftmunstycken: Framställa en säker och tillförlitlig mätmetod för att mäta mängd vatten i 50 provrör2018Independent thesis Basic level (university diploma), 20 poäng / 30 hpOppgave
    Abstract [sv]

    För att upptäcka defekta luftmunstycken har Ecco FinishingABi Skara tagit fram en ny provutrustning som ska ersätta en otillförlitlig och osäker befintlig provmaskin. Ecco Fi-nishing AB vill hitta en tillförlitlig och säker mätmetod som ska mäta mängd vatten i 50 provrör. Examensarbetets övergripande mål är att hitta en noggrann och repeterbarmätmetod för nivåmätning av vätska i provrören. Två mätmetoder utvärderades som är mest lämpliga för nivåmätningen, visionsystem och mätning genom vägning. Anledningen till att valet ham-nade på dessa två mätmetoder är provutrustningens provrör, dels att det är många mätpunkter och för att det är små provrör. Det gjordes tjugo experiment för visionsystem och tjugoex-periment för vägningsmetodför att utvärdera och beskriva för -och nackdelar. Experimenten av visionsystem och vägning gjordes först i laborationsfas för att sedan testas på företagets befintliga provutrustning. Resultaten av mätningar sparades i ett Excel-ark som användes för att utvärdera insamlade data. Utvärderingarna jämfördes mot uppsatta mål, tillförlitlighet, noggrannhet, repeterbarhet, automatisk rapportering av resultat och tid för mätningen. Vis-ionsystem rekommenderas för fortsatt arbete och implementation på den befintliga provut-rustningen.

  • 54.
    Potros, Bashar
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Framställning av mätmetod för att upptäcka defekta luftmunstycken: Framställa en säker och tillförlitlig mätmetod för att mäta mängd vatten i 50 provrör2018Independent thesis Basic level (degree of Bachelor), 20 poäng / 30 hpOppgave
    Abstract [sv]

    För att upptäcka defekta luftmunstycken har Ecco Finishing AB i Skara tagit fram en ny provutrustning som ska ersätta en otillförlitlig och osäker befintlig provmaskin. Ecco Fi-nishing AB vill hitta en tillförlitlig och säker mätmetod som ska mäta mängd vatten i 50 provrör. Examensarbetets övergripande mål är att hitta en noggrann och repeterbar mätmetod för nivåmätning av vätska i provrören. Två mätmetoder utvärderades som är mest lämpliga för nivåmätningen, visionsystem och mätning genom vägning. Anledningen till att valet ham-nade på dessa två mätmetoder är provutrustningens provrör, dels att det är många mätpunkter och för att det är små provrör. Det gjordes tjugo experiment för visionsystem och tjugo ex-periment för vägningsmetod för att utvärdera och beskriva för - och nackdelar. Experimenten av visionsystem och vägning gjordes först i laborationsfas för att sedan testas på företagets befintliga provutrustning. Resultaten av mätningar sparades i ett Excel-ark som användes för att utvärdera insamlade data. Utvärderingarna jämfördes mot uppsatta mål, tillförlitlighet, noggrannhet, repeterbarhet, automatisk rapportering av resultat och tid för mätningen. Vis-ionsystem rekommenderas för fortsatt arbete och implementation på den befintliga provut-rustningen.

  • 55.
    Racca, Mattia
    et al.
    School of Electrical Engineering, Aalto University, Finland.
    Pajarinen, Joni
    Intelligent Autonomous Systems (IAS) and Computational Learning for Autonomous Systems (CLAS) labs at TU Darmstadt.
    Montebelli, Alberto
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Kyrki, Ville
    School of Electrical Engineering, Aalto University, Finland.
    Learning in-contact control strategies from demonstration2016Inngår i: IROS 2016: 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, 2016, s. 688-695Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Learning to perform tasks like pulling a door handle or pushing a button, inherently easy for a human, can be surprisingly difficult for a robot. A crucial problem in these kinds of in-contact tasks is the context specificity of pose and force requirements. In this paper, a robot learns in-contact tasks from human kinesthetic demonstrations. To address the need to balance between the position and force constraints, we propose a model based on the hidden semi-Markov model (HSMM) and Cartesian impedance control. The model captures uncertainty over time and space and allows the robot to smoothly satisfy a task's position and force constraints by online modulation of impedance controller stiffness according to the HSMM state belief. In experiments, a KUKA LWR 4+ robotic arm equipped with a force/torque sensor at the wrist successfully learns from human demonstrations how to pull a door handle and push a button.

  • 56.
    Raupach, Staffan
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Lindelöw, Fredrik
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Virtual Value Stream Mapping: Evaluation of simulation based value stream mapping using Plant Simulation2015Independent thesis Basic level (degree of Bachelor), 20 poäng / 30 hpOppgave
    Abstract [en]

    VSM, Value stream mapping, V2SM, virtual value stream mapping, lean, lean manufacturing, DES, discrete event simulation, Tecnomatix Plant Simulation

  • 57.
    Richardson, Kathleen
    et al.
    De Montfort University, Leicester, United Kingdom.
    Coeckelbergh, Mark
    De Montfort University, Leicester, United Kingdom.
    Wakunuma, Kutoma
    De Montfort University, Leicester, United Kingdom.
    Billing, Erik
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Ziemke, Tom
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Gómez, Pablo
    Vrije Universiteit, Brussel, Belgium.
    Vanderborght, Bram
    Vrije Universiteit, Brussel, Belgium.
    Belpaeme, Tony
    University of Plymouth, Plymouth, United Kingdom.
    Robot Enhanced Therapy for Children with Autism (DREAM): A Social Model of Autism2018Inngår i: IEEE technology & society magazine, ISSN 0278-0097, E-ISSN 1937-416X, Vol. 37, nr 1, s. 30-39Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The development of social robots for children with autism has been a growth field for the past 15 years. This article reviews studies in robots and autism as a neurodevelopmental disorder that impacts socialcommunication development, and the ways social robots could help children with autism develop social skills. Drawing on ethics research from the EU-funded Development of Robot-Enhanced Therapy for Children with Autism (DREAM) project (framework 7), this paper explores how ethics evolves and developed in this European project.

  • 58.
    Rosén, Julia
    et al.
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Richardson, Kathleen
    De Montfort University, Leicester, United Kingdom.
    Lindblom, Jessica
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Billing, Erik
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    The Robot Illusion: Facts and Fiction2018Inngår i: Proceedings of Workshop in Explainable Robotics System (HRI), 2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    "To researchers and technicians working with robots on a daily basis, it is most often obvious what is part of the staging and not, and thus it may be easy to forget that illusions like these are not explicit and the that the general public may actually be deceived. Should the disclosure of the illusion be the responsibility of roboticists? Or should the assumption be that human beings, on the basis of their experiences as an audience in film, theatre, music or video gaming, assume the audience is able to enjoy the experience without needing to know everything in advance about how the illusion is created? Therefore, we believe that a discussion of whether or not researchers should be more transparent in what kinds of machines they are presenting is necessary. How can researchers present interactive robots in an engaging way, without misleading the audience?"

  • 59.
    Schmidt, Bernard
    et al.
    Högskolan i Skövde, Institutionen för teknik och samhälle. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Wang, Lihui
    Högskolan i Skövde, Institutionen för teknik och samhälle. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Active collision avoidance for human-robot collaborative manufacturing2012Inngår i: Proceedings of the SPS12 conference 2012, The Swedish Production Academy , 2012, s. 81-86Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In the human-robot collaborative manufacturing environment where humans and robots coexist, safety protection of human operators in real time is of paramount importance. This paper presents an approach for real-time active collision avoidance in augmented environment, where virtual 3D models of robots and real camera images of operators are used for monitoring and collision detection. A cost-effective depth camera is chosen for surveillance of any mobile foreign objects, including operators, which are not presented in the virtual 3D models. Two redundant Kinect sensors using structured light are used as the depth cameras for better area coverage and for eliminating possible blind spots in the surveillance area. Collision detection is performed by minumum distance. Processing applied on depth images includes background removal, filtering, labeling and points cloud generation. A prototype system is developed and linked to robot controllers for real-time robot control, with zero robot programming. According to the result of collision detection, it can alert an operator, stop a robot, or even move a robot away from an approaching operator. The results of a case study show that this approach can be applied to real-world applications such as human-robot collaborative assembly to safeguard human operators.

  • 60.
    Siegmund, Florian
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Dynamic Resampling for Preference-based Evolutionary Multi-objective Optimization of Stochastic Systems: Improving the efficiency of time-constrained optimization2016Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    In preference-based Evolutionary Multi-objective Optimization (EMO), the decision maker is looking for a diverse, but locally focused non-dominated front in a preferred area of the objective space, as close as possible to the true Pareto-front. Since solutions found outside the area of interest are considered less important or even irrelevant, the optimization can focus its efforts on the preferred area and find the solutions that the decision maker is looking for more quickly, i.e., with fewer simulation runs. This is particularly important if the available time for optimization is limited, as is the case in many real-world applications. Although previous studies in using this kind of guided-search with preference information, for example, withthe R-NSGA-II algorithm, have shown positive results, only very few of them considered the stochastic outputs of simulated systems.

    In the literature, this phenomenon of stochastic evaluation functions is sometimes called noisy optimization. If an EMO algorithm is run without any countermeasure to noisy evaluation functions, the performance will deteriorate, compared to the case if the true mean objective values are known. While, in general, static resampling of solutions to reduce the uncertainty of all evaluated design solutions can allow EMO algorithms to avoid this problem, it will significantly increase the required simulation time/budget, as many samples will be wasted on candidate solutions which are inferior. In comparison, a Dynamic Resampling (DR) strategy can allow the exploration and exploitation trade-off to be optimized, since the required accuracy about objective values varies between solutions. In a dense, converged population, itis important to know the accurate objective values, whereas noisy objective values are less harmful when an algorithm is exploring the objective space, especially early in the optimization process. Therefore, a well-designed Dynamic Resampling strategy which resamples the solution carefully, according to the resampling need, can help an EMO algorithm achieve better results than a static resampling allocation.

    While there are abundant studies in Simulation-based Optimization that considered Dynamic Resampling, the survey done in this study has found that there is no related work that considered how combinations of Dynamic Resampling and preference-based guided search can further enhance the performance of EMO algorithms, especially if the problems under study involve computationally expensive evaluations, like production systems simulation. The aim of this thesis is therefore to study, design and then to compare new combinations of preference-based EMO algorithms with various DR strategies, in order to improve the solution quality found by simulation-based multi-objective optimization with stochastic outputs, under a limited function evaluation or simulation budget. Specifically, based on the advantages and flexibility offered by interactive, reference point-based approaches, studies of the performance enhancements of R-NSGA-II when augmented with various DR strategies, with increasing degrees of statistical sophistication, as well as several adaptive features in terms of optimization parameters, have been made. The research results have clearly shown that optimization results can be improved, if a hybrid DR strategy is used and adaptive algorithm parameters are chosen according to the noise level and problem complexity. In the case of a limited simulation budget, the results allow the conclusions that both decision maker preferences and DR should be used at the same time to achieve the best results in simulation-based multi-objective optimization.

  • 61.
    Siegmund, Florian
    et al.
    Högskolan i Skövde, Institutionen för teknik och samhälle. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, USA.
    Karlsson, Alexander
    Högskolan i Skövde, Institutionen för teknik och samhälle. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för teknik och samhälle. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Dynamic Resampling for Guided Evolutionary Multi-Objective Optimization of Stochastic Systems2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In Multi-objective Optimization many solutions have to be evaluated in order to provide the decision maker with a diverse Pareto-front. In Simulation-based Optimization the number of optimization function evaluations is very limited. If preference information is available however, the available function evaluations can be used more effectively by guiding the optimization towards interesting, preferred regions. One such algorithm for guided search is the R-NSGA-II algorithm. It takes reference points provided by the decision maker and guides the optimization towards areas of the Pareto-front close to the reference points.In Simulation-based Optimization the modeled systems are often stochastic and a reliable quality assessment of system configurations by resampling requires many simulation runs. Therefore optimization practitioners make use of dynamic resampling algorithms that distribute the available function evaluations intelligently on the solutions to be evaluated. Criteria for sampling allocation can be a.o. objective value variability, closeness to the Pareto-front indicated by elapsed time, or the dominance relations between different solutions based on distances between objective vectors and their variability.In our work we combine R-NSGA-II with several resampling algorithms based on the above mentioned criteria. Due to the preference information R-NSGA-II has fitness information based on distance to reference points at its disposal. We propose a resampling strategy that allocates more samples to solutions close to a reference point.Previously, we proposed extensions of R-NSGA-II that adapt algorithm parameters like population size, population diversity, or the strength of the Pareto-dominance relation continuously to optimization problem characteristics. We show how resampling algorithms can be integrated with those extensions.The applicability of the proposed algorithms is shown in a case study of an industrial production line for car manufacturing.

  • 62.
    Siegmund, Florian
    et al.
    Högskolan i Skövde, Institutionen för teknik och samhälle. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, USA.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för teknik och samhälle. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Adaptive Guided Evolutionary Multi-Objective Optimization2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In Multi-objective Optimization many solutions have to be evaluated in order to provide the decision maker with a diverse Pareto-front. In Simulation-based Optimization the number of optimization function evaluations is very limited. If preference information is available however, the available function evaluations can be used more effectively by guiding the optimization towards interesting, preferred regions. One such algorithm for guided search is the Reference-point guided NSGA-II. It takes reference points provided by the decision maker and guides the optimization towards areas of the Pareto-front close to the reference points.We propose several extensions of R-NSGA-II. In the beginning of the optimization runtime the population is spread-out in the objective space while towards the end of the runtime most solutions are close to reference points. The purpose of a large population is to avoid local optima and to explore the search space which is less important when the algorithm has converged to the reference points. Therefore, we reduce the population size towards the end of the runtime. R-NSGA-II controls the objective space diversity through the epsilon parameter. We reduce the diversity in the population as it approaches the reference points. In a previous study we showed that R-NSGA-II keeps a high diversity until late in the optimization run which is caused by the Pareto-fitness. This slows down the progress towards the reference points. We constrain the Pareto-fitness to force a faster convergence. For the same reason an approach is presented that delays the use of the Pareto-fitness: Initially, the fitness is based only on reference point distance and diversity. Later, when the population has converged towards the Pareto-front, Pareto-fitness is considered as primary-, and distance as secondary fitness.

  • 63.
    Siegmund, Florian
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, USA.
    A Ranking and Selection Strategy for Preference-based Evolutionary Multi-objective Optimization of Variable-Noise Problems2016Inngår i: 2016 IEEE Congress on Evolutionary Computation (CEC), IEEE conference proceedings, 2016, s. 3035-3044Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In simulation-based Evolutionary Multi-objective Optimization the number of simulation runs is very limited, since the complex simulation models require long execution times. With the help of preference information, the optimization result can be improved by guiding the optimization towards relevant areas in the objective space, for example with the R-NSGA-II algorithm [9], which uses a reference point specified by the decision maker. When stochastic systems are simulated, the uncertainty of the objective values might degrade the optimization performance. By sampling the solutions multiple times this uncertainty can be reduced. However, resampling methods reduce the overall number of evaluated solutions which potentially worsens the optimization result. In this article, a Dynamic Resampling strategy is proposed which identifies the solutions closest to the reference point which guides the population of the Evolutionary Algorithm. We apply a single-objective Ranking and Selection resampling algorithm in the selection step of R-NSGA-II, which considers the stochastic reference point distance and its variance to identify the best solutions. We propose and evaluate different ways to integrate the sampling allocation method into the Evolutionary Algorithm. On the one hand, the Dynamic Resampling algorithm is made adaptive to support the EA selection step, and it is customized to be used in the time-constrained optimization scenario. Furthermore, it is controlled by other resampling criteria, in the same way as other hybrid DR algorithms. On the other hand, R-NSGA-II is modified to rely more on the scalar reference point distance as fitness function. The results are evaluated on a benchmark problem with variable noise landscape.

  • 64.
    Siegmund, Florian
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, USA.
    Dynamic Resampling for Preference-based Evolutionary Multi-Objective Optimization of Stochastic Systems2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In Multi-objective Optimization many solutions have to be evaluated in order to provide the decision maker with a diverse choice of solutions along the Pareto-front. In Simulation-based Optimization the number of optimization function evaluations is usually very limited due to the long execution times of the simulation models. If preference information is available however, the available number of function evaluations can be used more effectively. The optimization can be performed as a guided, focused search which returns solutions close to interesting, preferred regions of the Pareto-front. One such algorithm for guided search is the Reference-point guided Non-dominated Sorting Genetic Algorithm II, R-NSGA-II. It is a population-based Evolutionary Algorithm that finds a set of non-dominated solutions in a single optimization run. R-NSGA-II takes reference points in the objective space provided by the decision maker and guides the optimization towards areas of the Pareto-front close the reference points.

    In Simulation-based Optimization the modeled and simulated systems are often stochastic and a common method to handle objective noise is Resampling. Reliable quality assessment of system configurations by resampling requires many simulation runs. Therefore, the optimization process can benefit from Dynamic Resampling algorithms that distribute the available function evaluations among the solutions in the best possible way. Solutions can vary in their sampling need. For example, solutions with highly variable objective values have to be sampled more times to reduce their objective value standard error. Dynamic resampling algorithms assign as much samples to them as is needed to reduce the uncertainty about their objective values below a certain threshold. Another criterion the number of samples can be based on is a solution's closeness to the Pareto-front. For solutions that are close to the Pareto-front it is likely that they are member of the final result set. It is therefore important to have accurate knowledge of their objective values available, in order to be able to to tell which solutions are better than others. Usually, the distance to the Pareto-front is not known, but another criterion can be used as an indication for it instead: The elapsed optimization time. A third example of a resampling criterion can be the dominance relations between different solutions. The optimization algorithm has to determine for pairs of solutions which is the better one. Here both distances between objective vectors and the variance of the objective values have to be considered which requires a more advanced resampling technique. This is a Ranking and Selection problem.

    If R-NSGA-II is applied in a scenario with a stochastic fitness function resampling algorithms have to be used to support it in the best way and avoid a performance degradation due to uncertain knowledge about the objective values of solutions. In our work we combine R-NSGA-II with several resampling algorithms that are based on the above mentioned resampling criteria or combinations thereof and evaluate which are the best criteria the sampling allocation can be based on, in which situations.

    Due to the preference information R-NSGA-II has an important fitness information about the solutions at its disposal: The distance to reference points. We propose a resampling strategy that allocates more samples to solutions close to a reference point. This idea is then extended with a resampling technique that compares solutions based on their distance to the reference point. We base this algorithm on a classical Ranking and Selection algorithm, Optimal Computing Budget Allocation, and show how OCBA can be applied to support R-NSGA-II. We show the applicability of the proposed algorithms in a case study of an industrial production line for car manufacturing.

  • 65.
    Siegmund, Florian
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, East Lansing, USA.
    Hybrid Dynamic Resampling Algorithms for Evolutionary Multi-objective Optimization of Invariant-Noise Problems2016Inngår i: Applications of Evolutionary Computation: 19th European Conference, EvoApplications 2016, Porto, Portugal, March 30 – April 1, 2016, Proceedings, Part II / [ed] Giovanni Squillero, Paolo Burelli, 2016, Vol. 9598, s. 311-326Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In Simulation-based Evolutionary Multi-objective Optimization (EMO) the available time for optimization usually is limited. Since many real-world optimization problems are stochastic models, the optimization algorithm has to employ a noise compensation technique for the objective values. This article analyzes Dynamic Resampling algorithms for handling the objective noise. Dynamic Resampling improves the objective value accuracy by spending more time to evaluate the solutions multiple times, which tightens the optimization time limit even more. This circumstance can be used to design Dynamic Resampling algorithms with a better sampling allocation strategy that uses the time limit. In our previous work, we investigated Time-based Hybrid Resampling algorithms for Preference-based EMO. In this article, we extend our studies to general EMO which aims to find a converged and diverse set of alternative solutions along the whole Pareto-front of the problem. We focus on problems with an invariant noise level, i.e. a flat noise landscape.

  • 66.
    Siegmund, Florian
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Ng, Amos H. C.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, USA.
    Hybrid Dynamic Resampling for Guided Evolutionary Multi-Objective Optimization2015Inngår i: Evolutionary Multi-Criterion Optimization: 8th International Conference, EMO 2015, Guimarães, Portugal, March 29 --April 1, 2015. Proceedings, Part I / [ed] António Gaspar-Cunha, Carlos Henggeler Antunes, Carlos Coello Coello, Springer, 2015, s. 366-380Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In Guided Evolutionary Multi-objective Optimization the goal is to find a diverse, but locally focused non-dominated front in a decision maker’s area of interest, as close as possible to the true Pareto-front. The optimization can focus its efforts towards the preferred area and achieve a better result [9, 17, 7, 13]. The modeled and simulated systems are often stochastic and a common method to handle the objective noise is Resampling. The given preference information allows to define better resampling strategies which further improve the optimization result. In this paper, resampling strategies are proposed that base the sampling allocation on multiple factors, and thereby combine multiple resampling strategies proposed by the authors in [15]. These factors are, for example, the Pareto-rank of a solution and its distance to the decision maker’s area of interest. The proposed hybrid Dynamic Resampling Strategy DR2 is evaluated on the Reference point-guided NSGA-II optimization algorithm (R-NSGA-II) [9].

  • 67.
    Steinmetz, Franz
    et al.
    German Aerospace Center (DLR), Institute of Robotics and Mechatronics, Oberpfaffenhofen-Weßling, Germany.
    Montebelli, Alberto
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Kyrki, Ville
    Department of Electrical Engineering and Automation, Aalto Univeristy, Aalto, Finland.
    Simultaneous kinesthetic teaching of positional and force requirements for sequential in-contact tasks2015Inngår i: Proceedings of the 2015 IEEE-RAS International Conference on Humanoid Robots (Humanoids), IEEE Computer Society, 2015, s. 202-209Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper demonstrates a method for simulta-neous transfer of positional and force requirements for in-contact tasks from a human instructor to a robotic arm throughkinesthetic teaching. This is achieved by a specific use of thesensory configuration, where a force/torque sensor is mountedbetween the tool and the flange of a robotic arm endowedwith integrated torque sensors at each joint. The humandemonstration is modeled using Dynamic Movement Primitives.Following human demonstration, the robot arm is provided withthe capacity to perform sequential in-contact tasks, for examplewriting on a notepad a previously demonstrated sequence ofcharacters. During the reenactment of the task, the systemis not only able to imitate and generalize from demonstratedtrajectories, but also from their associated force profiles. In fact,the implemented framework is extended to successfully recoverfrom perturbations of the trajectory during reenactment andto cope with dynamic environments.

  • 68.
    Telander, Andreas
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Fahlgren, Jessica
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Building a new production line: Problems, pitfalls and how to gain social sustainability2015Independent thesis Basic level (university diploma), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis has been performed in collaboration with Volvo Cars Engine in Skövde, Sweden and Zhangjia-kou, China in order to receive a bachelor degree in automation engineering from the University of Skövde.

    The project focuses on analyzing the capacity of a future production line by using discrete event simulation. The production line is built in two different discrete event simulation software, FACTS analyzer and Plant Simulation. The focus of the study will be to compare the output results from the two software in order to give recommendations for which software to use in similar cases. This is done in order for Volvo Cars Corporation to have as a basis for further work in similar cases. The aim of the work is to verify the planned capacity of the new production line and to perform a leadership study with Chinese engineers in order to find out how they view the Swedish leadership and how this can be adapted to China and the Chinese culture and give recommendations for future work.

    The results of the capacity analysis show that the goals of parts produced can be reached for both planned capacities but also that there are potential constraints that have been identified in the system. The results of the leadership study also show that the overall approach should be slightly adapted to be better suited for the Chinese culture. The comparison of the two simulation software suggests that FACTS Analyzer is suit-able to use when less complex logic or systems are represented, however when building more complex models consisting of more complex logic Plant Simulation is more suitable.

  • 69.
    Thabet, Mohammad
    et al.
    Department of Intelligent Hydraulics and Automation, Tampere University of Technology, Finland.
    Montebelli, Alberto
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Kyrki, Ville
    Department of Electrical Engineering and Automation, Aalto University, Finland.
    Learning Movement Synchronization in Multi-component Robotic Systems2016Inngår i: : ICRA 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 249-256Konferansepaper (Fagfellevurdert)
  • 70.
    Thellman, Sam
    et al.
    Cognition & Interaction Lab, Department of Computer and Information Science, Linköping University, Linköping, Sweden.
    Silvervarg, Annika
    Cognition & Interaction Lab, Department of Computer and Information Science, Linköping University, Linköping, Sweden.
    Ziemke, Tom
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi. Cognition & Interaction Lab, Department of Computer and Information Science, Linköping University, Linköping, Sweden.
    Folk-Psychological Interpretation of Human vs. Humanoid Robot Behavior: Exploring the Intentional Stance toward Robots2017Inngår i: Frontiers in Psychology, ISSN 1664-1078, E-ISSN 1664-1078, Vol. 8, artikkel-id 1962Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    People rely on shared folk-psychological theories when judging behavior. These theories guide people's social interactions and therefore need to be taken into consideration in the design of robots and other autonomous systems expected to interact socially with people. It is, however, not yet clear to what degree the mechanisms that underlie people's judgments of robot behavior overlap or differ from the case of human or animal behavior. To explore this issue, participants (N = 90) were exposed to images and verbal descriptions of eight different behaviors exhibited either by a person or a humanoid robot. Participants were asked to rate the intentionality, controllability and desirability of the behaviors, and to judge the plausibility of seven different types of explanations derived from a recently proposed psychological model of lay causal explanation of human behavior. Results indicate: substantially similar judgments of human and robot behavior, both in terms of (1a) ascriptions of intentionality/controllability/desirability and in terms of (1b) plausibility judgments of behavior explanations; (2a) high level of agreement in judgments of robot behavior -(2b) slightly lower but still largely similar to agreement over human behaviors; (3) systematic differences in judgments concerning the plausibility of goals and dispositions as explanations of human vs. humanoid behavior. Taken together, these results suggest that people's intentional stance toward the robot was in this case very similar to their stance toward the human.

  • 71.
    Tykal, Martin
    et al.
    Aalto University, Finland.
    Montebelli, Alberto
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Kyrki, Ville
    Department of Electrical Engineering and Automation, Aalto University, Finland.
    Incrementally Assisted Kinesthetic Teaching for Programming by Demonstration2016Inngår i: Human-Robot Interaction (HRI), 2016 11th ACM/IEEE International Conference on: HRI 2016, IEEE Computer Society, 2016, s. 205-212Konferansepaper (Fagfellevurdert)
  • 72.
    Vernon, David
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Artificial Cognitive Systems: A Primer2014Bok (Fagfellevurdert)
    Abstract [en]

    This book offers a concise and accessible introduction to the emerging field of artificial cognitive systems. Cognition, both natural and artificial, is about anticipating the need for action and developing the capacity to predict the outcome of those actions. Drawing on artificial intelligence, developmental psychology, and cognitive neuroscience, the field of artificial cognitive systems has as its ultimate goal the creation of computer-based systems that can interact with humans and serve society in a variety of ways. This primer brings together recent work in cognitive science and cognitive robotics to offer readers a solid grounding on key issues.

  • 73.
    Vernon, David
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Cognitive System2014Inngår i: Computer Vision: A Reference Guide / [ed] Katsushi Ikeuchi, Boston: Springer, 2014, s. 100-106Kapittel i bok, del av antologi (Fagfellevurdert)
  • 74.
    Vernon, David
    et al.
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Beetz, Michael
    Institute for Artificial Intelligence, University of Bremen, Bremen, Germany.
    Giulio, Sandini
    Department of Robotics, Brain and Cognitive Sciences, Istituto Italiano di Tecnologia, Genova, Italy.
    Prospection in cognition: The case for joint episodic-procedural memory in cognitive robotics2015Inngår i: Frontiers in Robotics and AI, ISSN 2296-9144, Vol. 2, artikkel-id 19Artikkel i tidsskrift (Fagfellevurdert)
  • 75.
    Vernon, David
    et al.
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Billing, Erik
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Hemeren, Paul
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Thill, Serge
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Ziemke, Tom
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi. Department of Computer and Information Science, Linköping University, Sweden.
    An Architecture-oriented Approach to System Integration in Collaborative Robotics Research Projects: An Experience Report2015Inngår i: Journal of Software Engineering for Robotics, ISSN 2035-3928, E-ISSN 2035-3928, Vol. 6, nr 1, s. 15-32Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Effective system integration requires strict adherence to strong software engineering standards, a practice not much favoured in many collaborative research projects. We argue that component-based software engineering (CBSE) provides a way to overcome this problem because it provides flexibility for developers while requiring the adoption of only a modest number of software engineering practices. This focus on integration complements software re-use, the more usual motivation for adopting CBSE. We illustrate our argument by showing how a large-scale system architecture for an application in the domain of robot-enhanced therapy for children with autism spectrum disorder (ASD) has been implemented. We highlight the manner in which the integration process is facilitated by the architecture implementation of a set of placeholder components that comprise stubs for all functional primitives, as well as the complete implementation of all inter-component communications. We focus on the component-port-connector meta-model and show that the YARP robot platform is a well-matched middleware framework for the implementation of this model. To facilitate the validation of port-connector communication, we configure the initial placeholder implementation of the system architecture as a discrete event simulation and control the invocation of each component’s stub primitives probabilistically. This allows the system integrator to adjust the rate of inter-component communication while respecting its asynchronous and concurrent character. Also, individual ports and connectors can be periodically selected as the simulator cycles through each primitive in each sub-system component. This ability to control the rate of connector communication considerably eases the task of validating component-port-connector behaviour in a large system. Ultimately, over and above its well-accepted benefits for software re-use in robotics, CBSE strikes a good balance between software engineering best practice and the socio-technical problem of managing effective integration in collaborative robotics research projects. 

  • 76.
    Vernon, David
    et al.
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Thill, Serge
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    Ziemke, Tom
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    The Role of Intention in Cognitive Robotics2016Inngår i: Toward Robotic Socially Believable Behaving Systems: Volume I / [ed] Anna Esposito & Lakhmi C. Jain, Switzerland: Springer, 2016, s. 15-27Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    We argue that the development of robots that can interact effectively with people requires a special focus on building systems that can perceive and comprehend intentions in other agents. Such a capability is a prerequisite for all pro-social behaviour and in particular underpins the ability to engage in instrumental helping and mutual collaboration. We explore the prospective and intentional nature of action, highlighting the importance of joint action, shared goals, shared intentions, and joint attention in facilitating social interaction between two or more cognitive agents. We discuss the link between reading intentions and theory of mind, noting the role played by internal simulation, especially when inferring higher-level actionfocussed intentions. Finally, we highlight that pro-social behaviour in humans is the result of a developmental process and we note the implications of this for the challenge of creating cognitive robots that can read intentions.

  • 77.
    Vernon, David
    et al.
    Högskolan i Skövde, Institutionen för informationsteknologi. Högskolan i Skövde, Forskningscentrum för Informationsteknologi.
    von Hofsten, Claes
    Department of Psychology, University of Uppsala, Sweden.
    Fadiga, Luciano
    Section of Human Physiology, University of Ferrara, Italy / IIT@UniFe Center for Translational Neurophysiology, Istituto Italiano di Tecnologia, Ferrara, Italy.
    Desiderata for developmental cognitive architectures2016Inngår i: Biologically Inspired Cognitive Architectures, ISSN 2212-683X, E-ISSN 2212-6848, Vol. 18, s. 116-127Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper complements Ron Sun’s influential Desiderata for Cognitive Architectures by focussing on the desirable attributes of a biologically-inspired cognitive architecture for an agent with a capacity for autonomous development. Ten desiderata are identified, dealing with value systems & motives, embodiment, sensorimotor contingencies, perception, attention, prospective action, memory, learning, internal simulation, and constitutive autonomy. These desiderata are motivated by studies in developmental psychology, cognitive neuroscience, and enactive cognitive science. All ten focus on the ultimate aspects of cognitive development — why a feature is necessary and what it enables — rather on than the proximate mechanisms by which it can be realized. As such, the desiderata are for the most part neutral regarding the paradigm of cognitive science — cognitivist or emergent — that is adopted when designing a cognitive architecture. Where some element of a desideratum is specific to a particular paradigm, this is noted.

  • 78.
    Wang, Lihui
    et al.
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Mohammed, Abdullah
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Wang, Xi Vincent
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Schmidt, Bernard
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Energy-efficient robot applications towards sustainable manufacturing2018Inngår i: International journal of computer integrated manufacturing (Print), ISSN 0951-192X, E-ISSN 1362-3052, Vol. 31, nr 8, s. 692-700Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The cloud technology provides sustainable solutions to the modern industrial robotic cells. Within the context, the objective of this research is to minimise the energy consumption of robots during assembly in a cloud environment. Given a robot path and based on the inverse kinematics and dynamics of the robot from the cloud, a set of feasible configurations of the robot can be derived, followed by calculating the desirable forces and torques on the joints and links of the robot. Energy consumption is then calculated for each feasible configuration along the path. The ones with the lowest energy consumption are chosen. Since the energy-efficient robot configurations lead to reduced overall energy consumption, this approach becomes instrumental and can be applied to energy-efficient robotic assembly. This cloud-based energy-efficient approach for robotic applications can largely enhance the current practice as demonstrated by the results of three case studies, leading towards sustainable manufacturing.

  • 79.
    Wang, Lihui
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system. KTH Royal Institute of Technology, Stockholm, Sweden.
    Mohammed, Abdullah
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Wang, Xi Vincent
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Schmidt, Bernard
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Recent Advancements of Smart Manufacturing: An Example of Energy-Efficient Robot2016Inngår i: Proceedings of the 26th International Conference on Flexible Automation and Intelligent Manufacturing, 2016, s. 884-892Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The cloud technology provides sustainable solutions to the modern industrial robotic cells. Within the context, the objective of this research is to minimise the energy consumption of robots during assembly in a cloud environment. Given a trajectory and based on the inverse kinematics and dynamics of a robot from the cloud, a set of feasible configurations of the robot can be derived, followed by calculating the desirable forces and torques on the joints and links of the robot. Energy consumption is then calculated for each feasible configuration along the trajectory. The ones with the lowest energy consumption are chosen. Since the energy-efficient robot configurations lead to reduced overall energy consumption, this approach becomes instrumental and can be applied to energy-efficient robotic assembly.

  • 80.
    Wolak, Peter
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Johansson, Mattias
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap.
    Buffer optimisation of a packaging line using Volvo GTO's flow simulation methodology2019Independent thesis Basic level (degree of Bachelor), 20 poäng / 30 hpOppgave
    Abstract [en]

    With the rapid development of computers and their proven usability in manufacturing environments, simulation-based optimisation has become a recognised tool for proposing near-optimal results related to manufacturing system design and improvement. As a world-leading manufacturer within their field, Volvo GTO in Skövde, Sweden is constantly seeking internal development and has in recent years discovered the possibilities provided by flow simulation. The main aim of this thesis is to provide an optimal buffer size of a new post-assembly and packaging line (Konpack) yet to be constructed. A by-product of the flow simulation optimisation project in form of a flow simulation process evaluation was also requested.

    The simulation project started with a pre-study including the development of the frame of reference and an analysis of the literature focused on merging Lean philosophy with simulation-based optimisation. The simulation model was built based on both historical and estimated data. The optimisation results showed different buffer size alternatives depending on the throughput to be achieved, these are discussed, and near-optimal solutions presented for decision-making. Additionally, four experiments were carried out, both contributing to the model’s credibility as well as providing new and valuable insight to the stakeholders. The conclusions drawn from the optimisation and experiments indicate that Konpack will be able to meet the established throughput goals, provided that the suggested near-optimal solutions are considered. The experiments also unanimously point to the fact that Konpack has a built-in overcapacity, utilizable by optimising certain suggested input parameters.

    Additionally, an evaluation of the completeness of the standard simulation process employed by Volvo GTO is provided, concluding that no major changes are needed. Nevertheless, there is always room for improvement. Hence, future work regarding the flow simulation process at Volvo GTO is proposed.

12 51 - 80 of 80
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf