The Speed-Track is a prototype of tracked vehicle made for material transportation on yards andgalleries. It was realized in 2011 and during the past two years has been employed mainly forload transportation on mountains. The main innovations adopted by the vehicle are about thesuspension system and the hydrostatic transmission; the combination of both allows acomfortable driving up to a maximum speed of 20 km/h.First of all, the present thesis aims to quantitatively evaluate the performances of the vehiclefrom the point of view of the suspension system and the transmission. The design of the vehicle,in fact, has been driven by the designer’s experience and no preliminary simulations and sizingcomputations have been performed.According to the outcomes of the first step as well as the feedback, some improvements to thecurrent configuration are designed and evaluated. The feedback has been submitted to theprototype’s users through a questionnaire. Improvements are supposed to be easily implementedon the existing vehicle.The outcomes of the previous steps as well as the communication with employees andentrepreneurs and the knowledge of the state of the art in terms of construction and earthmovingmachines drive the last step of the present work.The employees and entrepreneurs consulted mainly work in the agricultural sector and they havebeen contacted through web-based forums. In addition, the participation to the fair Bauma 2013allowed us to get a more complete picture of the state of the art.New solutions, starting from scratch, are designed in the last part.Keywords: / Speed-Track är en prototyp av en spårfarkost utvecklad för materialtransport på gårdar och igallerior. Den konstruerades 2011 och under de senaste två åren har den främst använts för tungatransporter på berg.De huvudsakliga innovationerna av vilka farkosten använder sig av är kopplade tillsuspensionssystemet och den hydrostatiska transmissionen; kombinationen av dessa möjliggören bekväm resa i hastigheter upp till 20 km/h.Målet med detta examensarbete är framför allt att utvärdera prestandan hos farkosten medhänsyn till suspensionssystemet och transmissionen. Designen av farkosten har utformats baseratpå utvecklarens erfarenheter och inga preliminära simuleringar eller beräkningar har utförts.Baserat på resultaten från, och utvärdering av det första steget har vissa förbättringar till denrådande uppbyggnaden framtagits och utvärderats. Utvärderingen har lämnats till användare avprototypen genom ett frågeformulär.Förbättringarna skall vara lätta att tillämpa på den existerande farkosten.Resultaten från de föregående stegen tillsammans med en dialog med anställda och entreprenörersamt teknisk kunskap med avseende på konstruktion och jordfraktande maskiner driva det sistasteget av det presenterade arbetet.Medarbetare och entreprenörer härstammar framför allt från arbete inom jordbrukssektorn ochhar blivit kontaktade genom web-forum.Dessutom har medverkan under mässan Bauma 2013 givit en mer komplett bild av den rådandetekniken.Nya lösningar skapade från början utvecklas i arbetets sista del.

<p>The design of vehicle components for crashworthiness is one of the most challenging problems in the automotive industry. The safety of the occupants during a crash event relies on the energy absorption capability of vehicle structures. Therefore, the body components of a vehicle are required to be lightweight and highly integrated structures. Moreover, reducing vehicle weight is another crucial design requirement since fuel economy is directly related to the mass of a vehicle. In order to address these requirements, various design concepts for vehicle bodies have been proposed using high-strength steel and different aluminum alloys. However, the price factor has always been an obstacle to completely replace regular body steels with more advanced alloys. To this end, the integration of numerical simulation and structural optimization techniques has been widely practiced addressing these requirements. Advancements in nonlinear structural design have shown the promising potential to generate innovative, safe, and lightweight vehicle structures. In addition, the implementation of structural optimization techniques has the capability to shorten the design cycle time for new models. A reduced design cycle time can provide the automakers with an opportunity to stay ahead of their competitors. During the last few decades, enormous structural optimization methods were proposed. A vast majority of these methods use mathematical programming for optimization, a method that relies on availability sensitivity analysis of objective functions. Thus, due to the necessity of sensitivity analyses, these methods remain limited to linear (or partially nonlinear) material models under static loading conditions. In other words, these methods are no able to capture all non-linearities involved in multi-body crash simulation. As an alternative solution, heuristic approaches, which do need sensitivity analyses, have been developed to address structural optimization problems for crashworthiness. The Hybrid Cellular Automaton (HCA), as a bio-inspired algorithm, is a well-practiced heuristic method that has shown promising capabilities in the structural design for vehicle components. The HCA has been continuously developed during the last two decades and designated to solve specific structural design applications. Despite all advancements, some fundamental aspects of the algorithm are still not adequately addressed in the literature. For instance, the HCA numerically implemented as a closed-loop control system. The local controllers, which dictate the design variable updates, need parameter tuning to efficiently solve different sets of problems. Previous studies suggest that one can identify some default values for the controllers. However, still, there is no well-organized strategy to tune these parameters, and proper tuning still relies on the designer’s experience.</p> <p> </p> <p> Moreover, structures with multiple materials have now become one of the perceived necessities for the automotive industry to address vehicle design requirements such as weight, safety, and cost. However, structural design methods for crashworthiness, including the HCA, are mainly applied to binary structural design problems. Furthermore, the conventional methods for the design of multi-material structures do not fully utilize the capabilities of premium materials. In other words, the development of a well-established method for the design of multi-material structures and capable of considering the cost of the materials, bonding between different materials (especially categorical materials), and manufacturing considering is still an open problem. Lastly, the HCA algorithm relies only on one hyper-parameter, the mass fraction, to synthesize structures. For a given problem, the HCA only provides one design option directed by the mass constraint. In other words, the HCA cannot tailor the dynamic response of the structure, namely, intrusion and deceleration profiles.</p> <p> </p> <p>The main objective of this dissertation is to develop new methodologies to design structures for crashworthiness applications. These methods are built upon the HCA algorithm. The first contribution is about introducing s self-tuning scheme for the controller of the algorithm. The proposed strategy eliminates the need to manually tune the controller for different problems and improve the computational performance and numerical stability. The second contribution of this dissertation is to develop a systematic approach to design multi-material crashworthy structures. To this end, the HCA algorithm is integrated with an ordered multi-material SIMP (Solid Isotropic Material with Penalization) interpolation. The proposed multi-material HCA (MMHCA) framework is a computationally efficient method since no additional design variables are introduced. The MMHCA can synthesize multi-material structures subjected to volume fraction constraints. In addition, an elemental bonding method is introduced to simulate the laser welding applied to multi-material structures. The effect of the bonding strength on the final topology designs is studied using numerical simulations. In the last step, after obtaining the multi-material designs, the HCA is implemented to remove the desired number of bonding elements and reduce the weld length.</p> <p> </p> <p>The third contribution of this dissertation is to introduce a new Cluster-based Structural Optimization method (CBSO) for the design of multi-material structures. This contribution introduces a new Cluster Validity Index with manufacturing considerations referred to as CVI_m. The proposed index can characterize the quality of the cluster in structural design considering volume fraction, size, interface as a measure of manufacturability. This multi-material structural design approach comprises three main steps: generating the conceptual design using adaptive HCA algorithm, clustering of the design domain using Multi-objective Genetic Algorithm (MOGA) optimization. In the third step, MOGA optimization is used to choose categorical materials in order to optimize the crash indicators (e.g., peak intrusion, peak contact force, load uniformity) or the cost of the raw materials. The effectiveness of the algorithm is investigated using numerical examples.</p>

This thesis is a qualitative research and design project based on the concept of glitch. Glitch, typically associated with technical malfunctions, is examined here from a philosophical perspective with emphasis on the phenomenological aspect. A glitch in this thesis is seen as beyond an error; instead it is a moment of disruption, a subjective experience that prompt re-examination of our perception. By exploring the notion of glitch, the aim is to discover glitch given form and to challenge conventional design practices. The creative process involved theoretical exploration, qualitative interviews, and model making. Through research and interviews, a series of glitch volumes (X, Y, Z, W) were created based on personal glitch experiences.

En intégrant le cycle de vie d'un bien dans son processus de développement, l'éco-conception permet d'améliorer la performance environnementale de ce futur produit. La combinaison, dans cette thèse, des notions de la conception centrée utilisateur et de la pensée cycle de vie, permet de proposer une méthode pour l'intégration de la phase d'utilisation en éco-conception. La méthode repose sur la proposition de nouveaux modèles pour représenter l'utilisation adaptés aux spécificités de l'éco-conception. A partir du modèle de produit, un modèle de la phase d'utilisation, connectée aux phases de distribution et de fin de vie, permet d'associer l'utilisation du produit à son cycle de vie complet. Le modèle de contexte permet de positionner la performance environnementale du produit en utilisation par rapport à des paramètres associés à l'utilisateur et à l'environnement d'utilisation. L'évaluation environnementale du scénario d'utilisation regroupant tous ces modèles permet d'adapter les stratégies d'amélioration de la méthode à l'utilisation d'un produit en conception. Une application de la démarche à la re-conception d'un réfrigérateur pour la France et le Brésil permet d'illustrer le fonctionnement de la méthode. / By integrating product life cycle into the developement process, ecodesign enables the environnemental improvement of the product to be. The combination of user centred design proposition and life cycle thinking allows us to propose a method for use phase integration in ecodesign. This method is built on new models to represent product use that are compatible with ecodesign specificity. Based on the product model, the use phase model, which is connected to the distribution and end-of-life phases, facilitates the attachment of product use to the complete life cycle. Context model aims at possitionning the product use environmental performance according to influencing parameters related to the user and it environment. Environmental assessment is made based on the use scenario, a combination of the three previous models. This assessment enables to adapt the improvements strategies to the specificity of a product use phase. A case study has been perform to illustrate the capability of the new proposal to ecodesign a refrigerator for Brazil and for France.

Le secteur des communications sans fil a connu un essor considérable, soutenu par l’évolution des "smartphones" et par le développement des réseaux de capteurs sans fil et de l’Internet des Objets (connu en anglais sous le nom ‘IoT’ pour Internet of Things). Les applications actuelles visent l’autonomie énergétique des objets communicants et nécessitent la conception de circuits intégrés pouvant assurer à la fois un fonctionnement à hautes performances et à moindre coût. L’une des principales fonctions des systèmes de communications radiofréquences (RF) est la génération de fréquence, assurée par l’oscillateur. De nombreux efforts de conception sont ainsi nécessaires afin d’assurer les performances requises par les nouvelles applications sans fil. Nos travaux de recherche ont pour objectif de proposer une méthode de conception d’oscillateurs agiles à faible consommation au sein des systèmes d’émission-réception RF. Le travail s’est focalisé sur l’étude et l’optimisation des éléments constitutifs d’un oscillateur LC passif en technologie CMOS et sur la proposition d’une méthode de conception. La méthode proposée peut être exploitée pour différentes structures d’oscillateurs afin d’optimiser leurs performances essentiellement en termes de consommation de puissance et de bruit de phase. Cette méthode a été appliquée pour implémenter plusieurs VCOs en technologie CMOS. Une série de mesure sous pointes a permis de valider leur fonctionnement. La suite de ce travail de thèse est consacrée à la proposition d’une nouvelle topologie d’oscillateur LC reconfigurable à base d’inductance active dédiée aux applications multistandards faible coût / The rapid growth of the Internet of Things (IoT) applications and the wireless sensor networks boosts the need for low cost and low power radiofrequency (RF) transceivers. The voltage-controlled oscillator (VCO) is an essential building block of several RF transceivers. Design tradeoffs have been very stringent in terms of power consumption, phase-noise, area and tuning range. In this context, the aim of this work is to propose a design method, aiming to optimize the VCO design and to improve its performances essentially in terms of power consumption and phase noise.The first part of this thesis sets a study of the elements of passive LC oscillators in CMOS technology. The second part presents a complete design method, aiming to optimize the LC-VCO performance regarding the phase noise and power consumption. The evaluation of the proposed method is carried out with some test-cases in full CMOS technology. Many RF LC-VCOs have been implemented and measured. The final part of this thesis presents a new tunable VCO suitable for multi-standards applications. The frequency tuning of the VCO is ensured using an active inductor based on CMOS inverters. The desired bandwidth can be selected while achieving low surface area and low power consumption.

Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2018-09-26T13:12:32Z No. of bitstreams: 1 Augusto Masiero Gil_.pdf: 7085344 bytes, checksum: 32676c681f7f8f1de66f6a4b43f3e394 (MD5) / Made available in DSpace on 2018-09-26T13:12:32Z (GMT). No. of bitstreams: 1 Augusto Masiero Gil_.pdf: 7085344 bytes, checksum: 32676c681f7f8f1de66f6a4b43f3e394 (MD5) Previous issue date: 2018-05-29 / itt Performance - Instituto Tecnológico em Desempenho da Construção Civil / O concreto autoadensável (CAA) é conhecido por sua elevada fluidez e estabilidade reológica no estado fresco, enquanto que o concreto reforçado com fibras (CRF) é conhecido por sua elevada capacidade de absorção de energia, evitando a ruptura frágil do material. Na última década, tem sido buscada a sinergia destas tecnologias com o concreto autoadensável reforçado com fibras (CAA-RF), que, além de apresentar propriedades mecânicas avançadas, permite uma melhor dispersão das fibras. No entanto, a incorporação de fibras tende a ocasionar a perda de trabalhabilidade da mistura, devido ao intertravamento com os agregados e ao aumento da área superficial de materiais secos na mistura. Este trabalho teve como objetivo contribuir para o desenvolvimento de um método de dosagem de CAA-RF, relacionando propriedades nos estados fresco e endurecido. Assim, a composição da mistura é alterada de modo a incluir fibras, mantendo a mesma espessura de argamassa sobre os agregados e as fibras da mistura de CAA original, considerando a área superficial de seus componentes e a composição volumétrica. Foram realizadas dosagens com três tipos de fibras metálicas, de diferentes características geométricas, incorporadas em três teores, de modo a compor o diagrama de dosagem proposto. Os resultados dos ensaios realizados no estado fresco evidenciaram pequenas alterações em suas propriedades, com o aumento do espalhamento, porém atendendo às mesmas classes da mistura referência. Verificou-se, no entanto, que misturas com maiores teores de fibras mais longas e com maior fator de forma apresentaram maior perda de estabilidade e de dispersão das fibras, evidenciando a ocorrência de segregação pelo excesso de fluidez das misturas. A partir dos ensaios no estado endurecido foi possível verificar que a incorporação de fibras pelo método proposto contribuiu para o aumento das propriedades mecânicas das misturas, com exceção do módulo de elasticidade. Foram verificados valores de resistência à compressão na ordem de 84,5 MPa, com influência significativa do tipo de fibra, de acordo com a análise de variância realizada. A instabilidade de algumas misturas afetou a distribuição de fibras na seção fissurada, apesar de haver o aumento do fator de tenacidade com o teor de incorporação, principal parâmetro adotado no diagrama de dosagem proposto. / Self-consolidating concrete (SCC) is known for its high fluidity and rheological stability in the fresh state, while fiber reinforced concrete (FRC) is known for its high energy absorption capacity, avoiding fragile rupture. In the last decade, the synergy of these technologies has been researched with self-consolidating fiber-reinforced concrete (FR-SCC), which allows better dispersion of the fibers, in addition to the advanced mechanical properties. However, the incorporation of fibers tends to cause the mixture’s loss of workability due to its interlocking with the aggregates and the increase of dry materials’ surface area in the mixture. This study aimed to contribute to the development of a mix design method for FR-SCC, relating properties in the fresh and hardened states. Thus, the mixture composition is modified to include fibers maintaining the same mortar thickness over aggregates and fibers as in the original SCC mixture, considering the surface area of its components and the volumetric composition. Mixtures with three types of steel fibers, of different geometric characteristics, incorporated in three contents each in order to compose the proposed mix design nomogram. The results of the tests performed in the fresh state showed small changes in their properties, with the increase of the slump-flow, but attending the same classes of the reference mixture. It was verified, however, that mixtures with higher fiber content, longer and with higher aspect ratio, showed greater loss of stability and fiber dispersion, evidencing the occurrence of fiber segregation due to excess mixture fluidity. From the tests in the hardened state it was possible to verify that the incorporation of fibers by the proposed method contributed to the improvement of mechanical properties, with the exception of the modulus of elasticity. Compressive strength values were verified in the order of 84.5 MPa, with significant influence of the fiber type, according to the analysis of variance performed. Although the instability of some blends in the fresh state affected the distribution of fibers in the cracked section, the toughness factor increased with the incorporation content, main parameter adopted in the dosage diagram.

Submitted by Mariana Dornelles Vargas (marianadv) on 2015-05-27T15:38:29Z No. of bitstreams: 1 influencia_imagens.pdf: 14682107 bytes, checksum: dc2cff25918154d890f4213f219ac205 (MD5) / Made available in DSpace on 2015-05-27T15:38:29Z (GMT). No. of bitstreams: 1 influencia_imagens.pdf: 14682107 bytes, checksum: dc2cff25918154d890f4213f219ac205 (MD5) Previous issue date: 2013-03-27 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Uma das principais características do conceito de Design Estratégico utilizado nesta pesquisa é o uso de um método de projeto que propõe uma etapa denominada metaprojeto - um espaço para discussão do problema de design. Nesta etapa, utliza-se um tipo especial de pesquisa chamado Pesquisa Blue Sky. Esta é composta essencialmente de referências visuais externas ao contexto do que se está projetando, e busca revelar tendências e apresentar estímulos úteis para o projeto. Na presente investigação busca-se refletir sobre o papel de imagens não relacionadas ao problema de projeto - referências indiretas - como fontes de inspiração no processo criativo de design. Para tanto se aborda a questão do problema de projeto mal estruturado e o seu processo de resolução; o pensamento criativo; e o uso da imagem como referência. É proposto um método de pesquisa de caráter exploratório que inclui o desenvolvimento de lincográficos e visa avaliar como estas imagens específicas são utilizadas durante o processo projetual. Apresentam-se indícios que o uso de imagens indiretas auxilia na formulação de ideias mais conceituais por aumentar o tempo de reflexão dos indivíduos sobre o problema e sobre a solução. / One of the main characteristics of the Strategic Design concept adopted in this research is the use of a design method that proposes a stage called metadesign - a space for discussion of the design problem. At this stage, a special type of tool is used, called Blue Sky research. It is essentially composed by visual references, that are external to the design context, and reveals trends and offers useful stimuli in the project. The purpose of this investigation is to reflect about the role of images not directly related to the design problems - indirect references - as inspiration sources for the creative design process. To do so, several aspects are reviewed, such as the "Wicked problem" and it's solution process; creative process; and usage of images as reference. A exploratory research, which includes the development of linkographs, is proposed in order to evaluate how these specific images are used during the project process. Evidence is presented, showing that indirect references help the formulation of conceptual ideas, by increasing the reflection time of the individuals about the problem and about the solution.

Les processus de conception d'ingénierie mécanique sont souvent centrés sur la technologie et ont des difficultés à intégrer de façon adéquate les comportements des utilisateurs lors des utilisations du futur produit. Ce problème existe tout au long du cycle de vie du projet de développement du produit et est particulièrement visible lors des phases préliminaires de conception. Bien que les industries et les universités conviennent que les aspects humains sont importants pour le succès du produit, il existe peu de méthodes qui soutiennent les créateurs/concepteurs pour la prise encompte de ces facteurs lors des travaux de conception. Afin d'améliorer la performance du produit, notre recherche vise à apporter ou complémenter la conception technique fonctionnelle par une approche plus intégrée. Elle vise en particulier une meilleure intégration du comportement du couple produit/utilisateur dès la phase de conception. En effet, les concepteurs ont été obligés de mettre de côté l’objectif d’une machine entièrement automatisée et doit continuer à faire appel à l'utilisateur pour effectuer certaines tâches. Même si pour améliorer la productivité de la machine l'automatisation des systèmes de production est une voix intéressante, l'intervention humaine sur ces systèmes reste un besoin critique, or elle reste mal définie au stade de la conception. Dans notre cas, le système mécanique pourrait être un système de production, une machine, un produit ou tout autre outil manipulé par un utilisateur. Les conditions d'utilisation sont directement influencées par les travaux de conception, qui constituent également le principal facteur d'amélioration des performances du système. L'objectif de cette recherche est le développement d’une évaluation technique « top-down » et d’une conception d'ingénierie socio-technique pour intégrer les diverses bases de connaissances et en particulier le modèle de tâche. L’objectif est donc de développer une approche de conception comportementale non pas uniquement centrée sur la technologie mais aussi sur une approche socio-technique, afin d'aider les concepteurs à optimiser la performance du produit globalement dès les premières phases de conception. Ainsi, nous proposons une approche qui intègre lesdonnées comportementales système technique, utilisateur et utilisateur/technique. Ce travail porte sur la conception d'ingénierie multi-métiers et traite de l'élaboration d'une approche de conception comportementale pour aider les concepteurs à optimiser la performance du produit globalement dès la phase de conception grâce à la prise en compte des conditions d'utilisation et de la présence de l’utilisateur. Pour expérimenter ces travaux, un logiciel est en développement pour soutenir et permettre une utilisation systématique de cette «approche de conception comportementale» en l'intégrant dans le travail au quotidien du concepteur. / Mechanical engineering design processes are often technology-centered and have difficulties to integrate user’s behaviour in term of using the product adequately. This problem is encountered along the whole life cycle of a project, and is especially noticeable during the early design phase. Although, industry and academia agree that human aspects are important for the success of the product, there are few methods that support the designers concerning these factors in the synthesis part of the design works. Mechanical engineering design is connected with human behaviours targeted at and eventually leading to the development of the product. These behaviours take place all over the product lifecycle. In order to improve product performance, our research carefully thinks out a piece of research linking the user cantered and functional engineering design approached into an integrated package. It aims to a better integration of product and user behaviour during the early design phase. Designers have been obliged to set aside their dreams of a 100% machine due to the vitalrequirement of the user to perform some definite tasks with machines. While machine productivity and use conditions are the main reasons for automating production systems, human intervention on such systems remains a critical need and the tasks performed by the user remain poorly defined at the early design stage. The focus of this research is the development and evaluation of a top-down technical and socio-technical framework for engineering design, which integrates various knowledge bases and the task model. The rationale behind such a framework is to develop a behavioural design approach not in a technology-centered approach, but with a socio-technical approach, in order to help designers to optimize the product performance through taking into account using conditions and requirements during the early design phase. We propose here a design approach that integrates user’s and system’s behavioural data as design specifications. We attempt to provide seamless integration means by merging engineering data and user-centered data within the engineer’s toolkit. Otherwise, classical user-centered approach may seem difficult to handle by the whole design team : in this respect, this work provides a formal integration model in the framework in mechanical engineering design. This paper covers the multi-trade engineering design, and deals with the development of a behavioural design approach to help designers to optimize the product performance in the early design phase through taking into account utilization conditions and requirements. Finally, a software application is in development to support and allow a systematic utilization of the “behavioural design approach” by integrating it into the daily work of the designer.

En dépit de ses diverses caractérisations, la nature innovante des instruments de politique publique semble consacrer trois types d’innovation : (a) soit, des imitations, à un glissement de modalités près, d’instruments préexistants ; (b) soit des hybridations d’instruments plus ou moins contraignants ; (c) soit des assemblages d’instruments de nature méta-instrumentale. En admettant alors que tous les instruments découlent les uns des autres par le biais de ces trois chemins de conception, nous avons cherché à produire une méthode de conception fondant concomitamment, et autour d’un même modèle-objet, une capacité d’identification ex post des instruments innovants et une capacité ex ante d’innovation.Au terme d’une démarche de recherche-intervention, nous avons convenu de définir les instruments comme autant de chaînes de causalité préfigurées de l’action collective, et avons formulé un langage algorithmique autour d’un certain nombre d’éléments - des acteurs, des actions, des événements, des opérateurs logiques et des vecteurs d’impact – afin de les caractériser de façon ostensive. En consacrant une méthode d’évaluation de la nouveauté et de l’effectivité instrumentales, nous avons dès lors pu établir qu’un instrument est innovant s’il constitue une nouvelle chaîne de causalité opérant effectivement dans la réalité technico-sociale. De façon corollaire, innover un instrument revient alors à dessiner une nouvelle chaîne de causalité, ou à modifier les acteurs et les actions qui la composent.Afin d’illustrer et d’éprouver cette méthode de conception que nous qualifions de combinatoire, nous avons enfin cherché à interroger le caractère innovant du dispositif des certificats d’économie (CEE) et ce, en proposant un protocole d'évaluation et en formulant diverses pistes d'innovation. / Although it is diversely characterized, the innovative nature of instruments seems to follow three types of innovation: (a) imitations of existing instruments; (b) hybridizations of more or less coercive instruments; (c) or meta-conglomerations of instruments. After admitting that all instruments originate from one another through these three innovation paths and a unique object model, we tried to provide a new design method that would both enable the identification of innovative instruments and their design.Within the frame of intervention research, we agreed to define an instrument as a specific intended causal chain of public action, and formulated an algorithmic language along some instrumental elements (actors, actions, events, logical operators and impact vectors) in order to characterize instruments in an ostensive way. After developing a method to evaluate the newness and the effectivity of any instrument, we could more precisely define an innovative instrument as a new causal chain that is effectively implemented in the technical and social reality. As a corollary, innovating an instrument consists in designing a new causal chain, or modifying the actors and actions in it.Eventually, and in order to apply and test what we called a combinatory design method, we chose to question the innovative nature of the Energy Savings Certificates scheme (ESC). For this purpose, we elaborated an evaluation protocol and formulated several possible lines of innovation.

Alors même que les outils de gestion et systèmes d’information sont de plus en plus nombreux, certains auteurs en gestion pointent du doigt un manque de cohérence dans l’organisation pouvant conduire à une baisse de performance. La quête de cohérence doit alors être repensée, pour développer un contrôle de gestion capable de remplir à nouveau sa mission.Notre recherche porte sur le cas d’un groupe de concessions automobiles qui présente la particularité d’être multi-marque et en pleine phase de développement. La thèse revisite ainsi les fondamentaux du contrôle de gestion et apporte un nouvel éclairage en mobilisant la notion d’objet-frontière,en tant que médiateur et vecteur de coopération en l’absence de consensus dans l’organisation. Les résultats de la recherche tendent ainsi à montrer que les outils de gestion ayant les propriétés d’un objet-frontière,sont plus aptes à contribuer à la cohérence dans l’organisation. / Although information resource management and management tools are becoming more and more numerous, the management points to a lack of coherence in the organization that could lead to a decrease in performance. The search for coherence should be reconsidered to develop management control to be capable of fulfilling its primary mission. Our research focuses on the case of a group of automotive dealerships who has the distinction of being multi-brand and in full development phase.The thesis revisits the fundamentals of management control and provides new insights by engaging the concept of boundary object, as a mediator and co-vector in the absence of consensus within the organization.The research results thus suggest that the management tools with the properties of a boundary object, are more likely to contribute to the coherence in the organization.