• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 13
  • 13
  • 5
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Conception et Commande d’un Robot d’Assistance à la Personne / Design and Control of a Personal Assistant Robot

Qian, Yang 04 July 2013 (has links)
Ce travail s’inscrit dans le cadre de la conception et réalisation d’un robot d’assistance à la personne. Dans cette thèse, nous nous intéressons particulièrement à la conception, à la modélisation et à la commande d’un robot manipulateur mobile. La conception mécanique couplée à un outil de simulation dynamique multi-corps nous a permis d’obtenir un modèle virtuel très réaliste. Le modèle cinématique du système a été obtenu en utilisant la méthode D-H modifiée. L’approche Bond graph et la méthode de Lagrange ont permis de construire le modèle dynamique. Un algorithme hybride qui combine la pseudoinverse du jacobien et la méthode RRT a été proposé pour la planification de mouvement d’un manipulateur redondant et rechercher de configurations continues, stables et sans collision. Un contrôleur basé sur les réseaux de neurones a été introduit pour la commande coordonnée d’un manipulateur mobile. Cette méthode ne nécessite pas un modèle précis du robot. Les paramètres inconnus sont identifiés et compensés en utilisant des réseaux de neurones RBF. Un algorithme de contrôle similaire est présenté pour la commande force/position d’un manipulateur mobile qui est soumis à des contraintes holonomes et nonholonomes. L’étude de la main robotique a été effectuée séparément avant d’être couplée au reste du système. Les modèles cinématique et dynamique du système main-objet ont été obtenus en utilisant les approches mathématiques et bond graph. Un algorithme est proposé afin d’assurer une prise ferme, éviter les dérapages et suivre les mouvements désirés. Les validations des modèles et des différentes lois de commande ont été effectuées grâce à la co-simulation Matlab/modèle virtuel / The purpose of this thesis is to design, model and control of a personal assistant robot used for domestic tasks. In order to make the robot’s design more efficient, a virtual simulation system is built using dynamic simulation software. The kinematic model is set up based on modified D-H principle. The dynamic model is built using the Lagrange theorem and elaborated in Matlab. We also employ an energy-based approach for modeling and its bond graph notation ensures encapsulation of functionality, extendibility and reusability of each element of the model. A hybrid algorithm of combining the Jacobian pseudoinverse algorithm with Rapidly-Exploring Random Tree method is presented for collision-free path planning of a redundant manipulator. An intelligent robust controller based on neural network is introduced for the coordinated control of a mobile manipulator. This method does not require an accurate model of the robot. Unknown dynamic parameters of the mobile platform and the manipulator are identified and compensated in closed-loop control using RBF neural network. A similar control algorithm is presented for coordinated force/motion control of a mobile manipulator suffering both holonomic and nonholonomic constraints. Kinematics and dynamics of a dexterous hand manipulating an object with known shape by rolling contacts are derived. A computed torque control algorithm is presented to ensure firm grip, avoid slippage and well track a given motion imposed to the object. The validation of models and different control laws were made by the co-simulation Matlab / virtual model
12

Management of ergonomic aspects in early design phases using virtual reality : Mapping of ergonomic aspects in early design phases, How would mordern technology like VR be used? / Hantering av ergonomiska aspekter i tidigt konstruktonsfas genom använding av skenbar verklighet : Kartläggning av ergonomiska aspekter i tidiga konstruktionsfaser, Hur skulle modern teknik som skenbar verklighet användas?

Niemand, Ponthus, Saladdin, Aya January 2018 (has links)
Volvo Group är ett av världens ledande tillverkare av bland annat lastbilar, bussar, entreprenadmaskiner och motorer för marina och industriella applikationer. Volvo Group äger totalt 10 olika märken, dessa är: Volvo Trucks, UD Trucks, Renault Trucks, Mack Trucks, Group Trucks Asia & JVs, Volvo Construction Equipment, Volvo Bus, Volvo Penta, Volvo Financial Services och Governmental Sales. Initiativet till projektet togs av Metod och Processutvecklings avdelningen på Volvo Group Trucks Operations (GTO), som är den delen av Volvo Group som utför själva sammansättningen av lastbilar. Volvo GTO finns i flertal olika länder världen över vilket leder till att arbetsprocesserna kan skilja mellan länderna. För att kunna standardisera ett arbetssätt där konstruktören (komponent ägaren) tillsammans med geometri arkitekten kan göra en första ergonomisk analys på den berörda komponenten. För att detta ska vara möjligt så tog projektet fram en handbok på hur man som komponentägare skall gå tillväga för att få en så bra och korrekt analys som möjligt. I denna kandidatarbete tas det upp förslag på hur VR hade kunnat hjälpa till ett utvärderingsverktyg redan i konstruktionsstadiet när en ny produkt/komponent ska tas fram eller om det ska göras förbättringar på en befintlig komponent. Kandidatarbetet har valt att fokusera mest på hur konstruktören och geometri arkitekten ska kunna utvärdera de ergonomiska aspekterna med VR som hjälp. Projektet har undersökt två user case varav ett av dem presenteras i denna rapport. Detta gäller monteringen av värmeskydd. Anledningen till att just denna montering valdes är på grund av dess dåliga ergonomi och åtkomlighet. Projektet valde att göra både en RULA-analys och PLIBEL-analys. RULA-analysen gav hög totalpoäng, 7 av 7 medan PLIBEL endast är en analys på arbetsplatsen vilket gav ett bra underlag för fortsatt arbete. Studien visade att VR är ett väldigt bra hjälpmedel vid analys av ergonomiska aspekter i tidig design fas. Det ger relevanta resultat och har potential för besparingar i resurser och kostnader inom utvecklingsprocessen. För att förbättra kandidatarbetes resultat har det gjorts besök på ESI-Group som har gått in med stöttning i form av VR utrustning och workshop. Detta gav projektmedlemmarna en inblick på möjligheterna man har med VR. / Volvo Group is one of the Worlds leading manufacturer in the categories trucks, busses, construction equipment and engines for the marine and industrial applications. Volvo Group consist of many different brands 10 in total, these are: Volvo Trucks, UD Trucks, Renault Trucks, Mack Trucks, Group Trucks Asia & JVs, Volvo Construction Equipment, Volvo Bus, Volvo Penta, Volvo Financial Services and Governmental Sales. The initiative for the project came from Method and Process Development within Volvo Trucks Tuve Plant, department at Volvo Group Trucks Operations (GTO), which is the part of Volvo Group performing the actual production of the trucks. Volvo GTO is located worldwide in several different countries, which leads to different work processes. To standardize a method where the designer (component owner) together with the geometry architect can make a first ergonomics analysis of the concerned component. To make this possible, the project presented a manual on how the component owner should proceed to obtain as good and correct analysis of ergonomics as possible. This bachelor thesis makes suggestions for how VR would be helpful in the design phase as an evaluation tool during development of a new product/component or whether improvements should be made to an existing component. The thesis has focused mostly on how the designer and geometry architect can evaluate the ergonomics aspects with VR as a help, already in the design phase. The project has investigated two user cases. One of them is presented in this report. This applies to the installation of heat shield, the reason that this particular assembly was chosen is due to its poor ergonomics and accessibility. The project chose to do a RULA-analysis and PLIBEL-analysis. The RULA analysis gave a high total score, 7 out of 7, while PLIBEL was an analysis at the workplace. Both proved to be a good basis for continued work.  The study shows that VR is a great tool for analysis of the ergonomics aspects in early design phase. It gives relevant results and has the potential for savings in resources and cost in product development process. To improve the results of the thesis, there have been visits on ESI-Group which has sponsored the thesis in the form of VR equipment and workshop. This gave the project members an insight into the possibilities of VR.
13

Pour une approche complète de l'évaluation de fiabilité dans les microsystèmes / For a complete approach of microsystems reliability evaluation

Matmat, Mohamed 03 September 2010 (has links)
La complexité des microsystèmes, leur multidisciplinarité, l’hétérogénéité des matériaux utilisés et les interfaces avec l’environnement extérieur rendent difficiles l’évaluation et la maîtrise de leur fiabilité indispensables pour l’exploitation des nombreuses possibilités innovantes qu’ils offrent.L’approche que nous avons proposée dans ce travail, afin de prédire la fiabilité des microsystèmes, se fonde sur l’usage intensif de la modélisation et de la simulation, dans les conditions d’usage du microsystème (profil de mission), en associant donc l’évaluation de la fiabilité à la démarche de conception : avant d’entreprendre une modélisation fonctionnelle de type VHDL-AMS, les objectifs de fiabilité sont exprimés explicitement dans le cahier des charges du microsystème, au même titre que les objectifs plus habituels de performances.Afin de supporter nos travaux, nous avons appliqué cette démarche de prédiction de la fiabilité sur deux types de microsystèmes :- des micro-actionneurs électrothermiques. - des commutateurs RF capacitifs à actionnement électrostatique / The complexity of microsystems, their multidisciplinarity, the heterogeneity of materials and interfaces with the external environment makes difficult the assessment and control of reliability, which is indispensable for the exploitation of the several innovative opportunities that they offer. The approach we proposed, in this work, to predict the reliability of microsystems is based on the intensive use of modelling and simulation, in the use and environmental conditions of micro-system (mission profile), thus by combining the reliability evaluation in the design process: before undertaking any type of functional modelling VHDL-AMS, reliability objectives are expressed explicitly in the specification of the micro-system, as well as the most common performance goals.To support our work, we applied this approach for predicting the reliability for two types of microsystems:- Electro-thermal micro-actuators.- Capacitive RF MEMS switches

Page generated in 0.0564 seconds