Download or read book Contribution l tude d un nouveau robot parall le 2 delta six degr s de libert avec d couplage written by Ahmed Goudali and published by . This book was released on 1995 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'USAGE DES ROBOTS PARALLELES (OU STRUCTURES A CHAINES CINEMATIQUES FERMEES) EN ROBOTIQUE S'IMPOSE PROGRESSIVEMENT EN RAISON DE L'INTERET CONSIDERABLE QU'IL PROCURE EN RIGIDITE, RAPIDITE, LEGERETE, ETC LA STRUCTURE DE STEWART OU SIMULATEUR DE VOL CONSTITUE L'APPLICATION LA PLUS POPULAIRE. POUR NOTRE PART, NOUS AVONS DEVELOPPE UNE STRUCTURE PARALLELE INEDITE A 6 D.D.1, QUE NOUS AVONS NOMMEE ROBOT 2-DELTA. ELLE EST CONSTITUEE PAR DEUX STRUCTURES DELTA IMBRIQUEES ; LA PREMIERE CORRESPONDANT AU ROBOT DELTA INITIAL DE CLAVEL NE COMMANDE QUE LES MOUVEMENTS PARALLELE A LA BASE, LA SECONDE COMMANDE UNIQUEMENT LES ORIENTATIONS DE LA PINCE. CES DEUX STRUCTURES PERMETTENT DE DECOUPLER LES MOUVEMENTS DE TRANSLATION ET DE ROTATION DE LA PINCE. NOUS AVONS PU MODELISER ANALYTIQUEMENT CETTE STRUCTURE ET INTRODUIRE PAR LA SUITE DEUX MODELES GEOMETRIQUES COMPLETS PERMETTANT D'ETABLIR LES RELATIONS ENTRE LES COORDONNEES OPERATIONNELLES DE L'EFFECTEUR, LES VARIABLES ARTICULAIRES ACTIVES ET LES VARIABLES ARTICULAIRES PASSIVES. L'EXPLOITATION DE CES MODELES ET L'ETUDE DES LIMITES DES DIFFERENTES VARIABLES NOUS A PERMIS D'ETUDIER EFFICACEMENT L'ESPACE DE TRAVAIL DU ROBOT 2-DELTA. UN AUTRE ASPECT DE L'ETUDE EST L'INFLUENCE DES PETITES VARIATIONS (OU JEUX) DES LONGUEURS DES BIELLETTES DE LA STRUCTURE EXTERIEURE ET INTERIEURE DU ROBOT 2-DELTA AUTOUR DE LEURS VALEURS NOMINALES SUR LES COORDONNEES OPERATIONNELLES DE LA PINCE. L'EXPLOITATION DE CETTE ETUDE NOUS A PERMIS DE DEFINIR DES ELLIPSOIDES DE JEU BASEES SUR LE CONCEPT DES ELLIPSOIDES DE MANIPULABILITE DE YOSHIKAWA. ENFIN, LA SIMULATION ET L'ANIMATION DU ROBOT 2-DELTA SUR LE SYSTEME DE C.A.O-ROBOTIQUE SMAR (SYSTEME DE SIMULATION ET D'ANIMATION DE ROBOT) A PERMIS DE VALIDER L'ENSEMBLE DE NOS CALCULS ET DE VISUALISER LES FONCTIONNALITES DU ROBOT 2-DELTA

Download or read book Design and analysis of a novel kinematically redundant parallel robot with all actuators located at the base written by Zhou Zhou (Auteur de Design and analysis of a novel kinematically redundant parallel robot with all actuators located at the base) and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cette thèse propose et analyse un nouveau robot parallèle cinématiquement redondant (KRP) avec tous les actionneurs situés à la base. La structure de base du robot provient de travaux antérieurs, c'est-à-dire que trois jambes avec 3 degrés de liberté (ddls) chacune sont attachées à la plate-forme mobile par trois liaisons redondantes, ce qui donne un robot KRP avec (6+3) degrés de liberté. Cette thèse se concentre sur quatre thèmes. Tout d'abord, un nouveau robot parallèle à 3 ddls utilisé comme jambe du robot KRP est proposé, et tous les actionneurs sont situés à la base afin de réduire l'inertie des parties mobiles. De plus, les actionneurs sont placés près les uns des autres pour minimiser l'encombrement et produire un espace de travail relativement grand. Les problèmes cinématiques tels que la modélisation cinématique, le problème inverse/direct, l'analyse des singularités et l'espace de travail sont analysés en détail. En outre, pour simplifier l'analyse de l'espace de travail et agrandir l'espace de travail, une conception améliorée du robot à 3 ddls est proposée. L'établissement de modèles dynamiques pour les robots parallèles est un défi en raison des relations complexes entre les vitesses et les forces induites par leur structure en boucle fermée. Cette thèse propose plusieurs méthodes de modélisation simplifiées pour les robots parallèles. Le premier type est dérivé de l'approche lagrangienne et l'idée centrale est de réduire la complexité des expressions représentant l'énergie pour le robot. Par conséquent, ces méthodes ont une bonne généralité et sont disponibles pour divers robots parallèles. Cependant, pour certains robots parallèles (par exemple, le robot à 3 ddls proposé), même en utilisant la méthode simplifiée, les calculs d'énergie sont légèrement complexes. Compte tenu de cela, une autre méthode de modélisation simplifiée basée sur l'approche de Newton-Euler est proposée et analysée. Étant donné que le nouveau robot KRP a une structure similaire à celle des robots KRP précédents, la plupart des méthodes analysées dans les travaux précédents peuvent être directement utilisées. Par conséquent, cette thèse ne résout que brièvement le problème inverse/direct, explique la singularité du point de vue de la force, donne le modèle dynamique et montre la structure et le modèle CAO du prototype du nouveau robot KRP. Enfin, cette thèse propose une méthode générale de contrôle de préhension par laquelle le robot KRP peut faire fonctionner à distance une pince pour générer les forces de préhension requises tout en déplaçant la plate-forme, toutes les actions étant pilotées par les mêmes actionneurs. Le modèle de contrôle de préhension se compose d'un modèle de contrôle du mouvement des jambes et d'un modèle de contrôle de la force des jambes, où la force de préhension peut être contrôlée indépendamment. En conséquence, le modèle de contrôle en force utilise un contrôleur en boucle ouverte, simple à mettre en œuvre et efficace.

Download or read book Reconfigurable Cable Driven Parallel Mechanism written by Khaled Mohamed Youssef and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the fast growth in industry and in order to reduce manufacturing budget, increase the quality of products and increase the accuracy of manufactured products in addition to assure the safety of workers, people relied on mechanisms for such purposes. Recently, cable driven parallel mechanisms (CDPMs) have attracted much attention due to their many advantages over conventional parallel mechanisms, such as the significantly large workspace and the dynamics capacity. In addition, it has lower mass compared to other parallel mechanisms because of its negligible mass cables compared to the rigid links. In many applications it is required that human interact with machines and robots to achieve tasks precisely and accurately. Therefore, a new domain of scientific research has been introduced, that is human robot interaction, where operators can share the same workspace with robots and machines such as cable driven mechanisms. One of the main requirements due to this interaction that robots should respond to human actions in accurate, harmless way. In addition, the trajectory of the end effector is coming now from the operator and it is very essential that the initial trajectory is kept unchanged to perform tasks such assembly, operating or pick and place while avoiding the cables to interfere with each other or collide with the operator. Accordingly, many issues have been raised such as control, vibrations and stability due the contact between human and robot. Also, one of the most important issues is to guarantee collision free space (to avoid collision between cables and operator and to avoid collisions between cables itself). The aim of this research project is to model, design, analysis and implement reconfigurable six degrees of freedom parallel mechanism driven by eight cables. The main contribution of this work will be as follow. First, develop a nonlinear model and solve the forward and inverse kinematics issue of a fully constrained CDPM given that the attachment points on the rails are moving vertically (conventional cable driven mechanisms have fixed attachment points on the rails) while controlling the cable lengths. Second, the new idea of reconfiguration is then used to avoid interference between cables and between cables and operator limbs in real time by moving one cable's attachment point on the frame to increase the shortest distance between them while keeping the trajectory of the end effector unchanged. Third, the new proposed approach was tested by creating a simulated intended cable-cable and cable-human interference trajectory, hence detecting and avoiding cable-cable and cable-human collision using the proposed real time reconfiguration while maintaining the initial end effector trajectory. Fourth, study the effect of relocating the attachment points on the constant-orientation wrench feasible workspace of the CDPM. En raison de la croissance de la demande de produits personnalisés et de la nécessité de réduire les coûts de fabrication tout en augmentant la qualité des produits et en augmentant la personnalisation des produits fabriqués en plus d'assurer la sécurité des travailleurs, les concepteurs se sont appuyés sur des mécanismes robotiques afin d'atteindre ces objectifs. Récemment, les mécanismes parallèles entraînés par câble (MPEC) ont attiré beaucoup d'attention en raison de leurs nombreux avantages par rapport aux mécanismes parallèles conventionnels, tels que l'espace de travail considérablement grand et la capacité dynamique. De plus, ce mécanisme a une masse plus faible par rapport à d'autres mécanismes parallèles en raison de ses câbles de masse négligeable comparativement aux liens rigides. Dans de nombreuses applications, il est nécessaire que l'humain interagisse avec les machines et les robots pour réaliser des tâches avec précision et rapidité. Par conséquent, un nouveau domaine de recherche scientifique a été introduit, à savoir l'interaction humain-robot, où les opérateurs peuvent partager le même espace de travail avec des robots et des machines telles que les mécanismes entraînés par des câbles. L'une des principales exigences en raison de cette interaction que les robots doivent répondre aux actions humaines d'une manière sécuritaire et collaboratif. En conséquence, de nombreux problèmes ont été soulevés tels que la commande et la stabilité dues au contact physique entre l'humain et le robot. Aussi, l'un des enjeux les plus importants est de garantir un espace sans collision (pour éviter les collisions entre des câbles et un opérateur et éviter les collisions entre les câbles entre eux). Le but de ce projet de recherche est de modéliser, concevoir, analyser et mettre en œuvre un mécanisme parallèle reconfigurable à six degrés de liberté entraîné par huit câbles. La principale contribution de ces travaux de recherche est de développer un modèle non linéaire et résolvez le problème de cinématique direct et inverse d'un CDPM entièrement contraint étant donné que les points d'attache sur les rails se déplacent verticalement (les mécanismes entraînés par des câbles conventionnels ont des points d'attache fixes sur les rails) tout en contrôlant les longueurs des câbles. Dans une deuxième étape, l'idée de la reconfiguration est ensuite utilisée pour éviter les interférences entre les câbles et entre les câbles et les membres d'un opérateur en temps réel en déplaçant un point de fixation du câble sur le cadre pour augmenter la distance la plus courte entre eux tout en gardant la trajectoire de l'effecteur terminal inchangée. Troisièmement, la nouvelle approche proposée a été évaluée et testée en créant une trajectoire d'interférence câble-câble et câble-humain simulée, détectant et évitant ainsi les collisions câble-câble et câble-humain en utilisant la reconfiguration en temps réel proposée tout en conservant la trajectoire effectrice finale. Enfin la dernière étape des travaux de recherche consiste à étudiez l'effet du déplacement des points d'attache sur l'espace de travail réalisable du CDPM.

Download or read book Techniques Pour Les Op rations Air sol Dans Les Situations de Conflits Localis s Et de R actions Rapides written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Mission Systems Panel. Symposium and published by . This book was released on 1996 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radiation Protection Activities written by United States. Environmental Protection Agency. Office of Radiation Programs and published by . This book was released on 1976 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dictionary of Technical Terms for Aerospace Use written by United States. National Aeronautics and Space Administration. Scientific and Technical Information Division and published by . This book was released on 1965 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Brief definitions "intended to be as clear as possible to the non-expert, but accuracy has not been compromised for the sake of readability. Mathematics has been used where necessary to avoid ambiguity."--Intro. Published 1965.

Download or read book Sovereign Debt Diplomacies written by Pierre Penet and published by Oxford University Press. This book was released on 2021 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an open access title available under the terms of a CC BY-NC-ND 4.0 International licence. It is free to read at Oxford Scholarship Online and offered as a free PDF download from OUP and selected open access locations. Sovereign Debt Diplomacies aims to revisit the meaning of sovereign debt in relation to colonial history and postcolonial developments. It offers three main contributions. The first contribution is historical. The volume historicises a research field that has so far focused primarily on the post-1980 years. A focus on colonial debt from the 19th century building of colonial empires to the decolonisation era in the 1960s-70s fills an important gap in recent debt historiographies. Economic historians have engaged with colonialism only reluctantly or en passant, giving credence to the idea that colonialism is not a development that deserves to be treated on its own. This has led to suboptimal developments in recent scholarship. The second contribution adds a 'law and society' dimension to studies of debt. The analytical payoff of the exercise is to capture the current developments and functional limits of debt contracting and adjudication in relation to the long-term political and sociological dynamics of sovereignty. Finally, Sovereign Debt Diplomacies imports insights from, and contributes to the body of research currently developed in the Humanities under the label 'colonial and postcolonial studies'. The emphasis on 'history from below' and focus on 'subaltern agency' usefully complement the traditional elite-perspective on financial imperialism favoured by the British school of empire history.

Download or read book Taming Capitalism Before Its Triumph written by Koji Yamamoto and published by Oxford University Press. This book was released on 2018 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: Early modern England had a distinctive preoccupation with the social responsibilities of private businesses. Koji Yamamoto explores for the first time how promises of public service in the economic sphere came to be abused, and how statesmen, playwrights, petitioners, and merchants responded to such perversions of promised public service.

Download or read book Telepresence Bio Art written by Eduardo Kac and published by University of Michigan Press. This book was released on 2005 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Eduardo Kac's work represents a turning point. What it questions is our current attitudes to creativity, taking that word in its most fundamental sense." -Edward Lucie-Smith, author of Visual Arts in the 20th Century "His works introduce a vital new meaning into what had been known as the creative process while at the same time investing the notion of the artist-inventor with an original social and ethical responsibility." -Frank Popper, author of Origins and Development of Kinetic Art "Kac's radical approach to the creation and presentation of the body as a wet host for artificial memory and 'site-specific' work raises a variety of important questions that range from the status of memory in digital culture to the ethical dilemmas we are facing in the age of bioengineering and tracking technology." -Christiane Paul, Whitney Museum of Art For nearly two decades Eduardo Kac has been at the cutting edge of media art, first inventing early online artworks for the web and continuously developing new art forms that involve telecommunications and robotics as a new platform for art. Interest in telepresence, also known as telerobotics, exploded in the 1990s, and remains an important development in media art. Since that time, Kac has increasingly moved into the fields of biology and biotechnology. Telepresence and Bio Art is the first book to document the evolution of bio art and the aesthetic development of Kac, the creator of the "artist's gene" as well as the controversial glow-in-the-dark, genetically engineered rabbit Alba. Kac covers a broad range of topics within media art, including telecommunications media, interactive systems and the Internet, telematics and robotics, and the contact between electronic art and biotechnology. Addressing emerging and complex topics, this book will be essential reading for anyone interested in contemporary art.

Download or read book The Japanese Economy During the Great Depression written by Masato Shizume and published by Springer Nature. This book was released on 2021-09-25 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a systematic explanation of a remarkable policy innovation in an emerging economy in the modern world. In doing so, it highlights the nature of the Japanese economy during the interwar period. It offers a canonical case study for an international macroeconomic policy of a small and open economy. Readers can draw lessons from the Japanese experience in the 1930s, recalling what kinds of challenges policymakers faced in a crisis situation, what they can do, and what they should not do. As a whole, it is a novel reference both for scholars in economic history and international economics and for policymakers all over the world. A comprehensive and clear-cut picture of the Japanese economy during the Great Depression in the 1930s is presented, including the policy innovations brought about by an iconoclastic finance minister, Korekiyo Takahashi, at that time. To this end, the book integrates the narrative analysis based on newly available archival documents and the quantitative analysis based on newly constructed macroeconomic data and contemporary econometric methodologies. This work shows how Japan escaped from the depression in its early stage. It illustrates a transmission mechanism of the macroeconomic stimulus package of currency depreciation, easy money, and fiscal expansion. As well, it argues that the key for economic recovery was currency depreciation and that expectations played a pivotal role in ending deflation and kick-starting economic recovery. Also contained here is an exploration of politico-economic interaction in the shaping of economic policy and the long-term consequences of policy actions such as departure from the gold standard and initiation of the government debt finance by the central bank. It is shown that the collapse of the international gold standard and the lack of governance of military spending resulted in a loss of fiscal discipline in the long run.

Download or read book The British Industrial Revolution in Global Perspective written by Robert C. Allen and published by Cambridge University Press. This book was released on 2009-04-09 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Why did the industrial revolution take place in 18th century Britain and not elsewhere in Europe or Asia? Robert Allen argues that the British industrial revolution was a successful response to the global economy of the 17th and 18th centuries.

Download or read book Before and Beyond Divergence written by Jean-Laurent Rosenthal and published by Harvard University Press. This book was released on 2011-04 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: Why did sustained economic growth arise in Europe rather than in China? The authors combine economic theory and historical evidence to argue that political processes drove the economic divergence between the two world regions, with continued consequences today that become clear in this innovative account.

Download or read book Dark Matter Credit written by Philip T. Hoffman and published by Princeton University Press. This book was released on 2019-02-05 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: How a vast network of shadow credit financed European growth long before the advent of banking Prevailing wisdom dictates that, without banks, countries would be mired in poverty. Yet somehow much of Europe managed to grow rich long before the diffusion of banks. Dark Matter Credit draws on centuries of cleverly collected loan data from France to reveal how credit abounded well before banks opened their doors. This incisive book shows how a vast system of shadow credit enabled nearly a third of French families to borrow in 1740, and by 1840 funded as much mortgage debt as the American banking system of the 1950s. Dark Matter Credit traces how this extensive private network outcompeted banks and thrived prior to World War I—not just in France but in Britain, Germany, and the United States—until killed off by government intervention after 1918. Overturning common assumptions about banks and economic growth, the book paints a revealing picture of an until-now hidden market of thousands of peer-to-peer loans made possible by a network of brokers who matched lenders with borrowers and certified the borrowers’ creditworthiness. A major work of scholarship, Dark Matter Credit challenges widespread misperceptions about French economic history, such as the notion that banks proliferated slowly, and the idea that financial innovation was hobbled by French law. By documenting how intermediaries in the shadow credit market devised effective financial instruments, this compelling book provides new insights into how countries can develop and thrive today.

Download or read book Operational Radiation Protection written by International Atomic Energy Agency and published by . This book was released on 1990 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides practical guidance on the application of the dose limitation system contained in the Basic Safety Standards for Radiation Protection, Safety Series No. 9, to operational situations both in large nuclear installations and in much smaller facilities, with special reference to the principles of optimisation.

Download or read book Ages of American Capitalism written by Jonathan Levy and published by Random House Trade Paperbacks. This book was released on 2022-04-05 with total page 945 pages. Available in PDF, EPUB and Kindle. Book excerpt: A leading economic historian traces the evolution of American capitalism from the colonial era to the present—and argues that we’ve reached a turning point that will define the era ahead. “A monumental achievement, sure to become a classic.”—Zachary D. Carter, author of The Price of Peace In this ambitious single-volume history of the United States, economic historian Jonathan Levy reveals how capitalism in America has evolved through four distinct ages and how the country’s economic evolution is inseparable from the nature of American life itself. The Age of Commerce spans the colonial era through the outbreak of the Civil War, and the Age of Capital traces the lasting impact of the industrial revolution. The volatility of the Age of Capital ultimately led to the Great Depression, which sparked the Age of Control, during which the government took on a more active role in the economy, and finally, in the Age of Chaos, deregulation and the growth of the finance industry created a booming economy for some but also striking inequalities and a lack of oversight that led directly to the crash of 2008. In Ages of American Capitalism, Levy proves that capitalism in the United States has never been just one thing. Instead, it has morphed through the country’s history—and it’s likely changing again right now. “A stunning accomplishment . . . an indispensable guide to understanding American history—and what’s happening in today’s economy.”—Christian Science Monitor “The best one-volume history of American capitalism.”—Sven Beckert, author of Empire of Cotton

Download or read book The Rise and Fall of Imperial China written by Yuhua Wang and published by Princeton University Press. This book was released on 2022-10-11 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: How social networks shaped the imperial Chinese state China was the world’s leading superpower for almost two millennia, falling behind only in the last two centuries and now rising to dominance again. What factors led to imperial China’s decline? The Rise and Fall of Imperial China offers a systematic look at the Chinese state from the seventh century through to the twentieth. Focusing on how short-lived emperors often ruled a strong state while long-lasting emperors governed a weak one, Yuhua Wang shows why lessons from China’s history can help us better understand state building. Wang argues that Chinese rulers faced a fundamental trade-off that he calls the sovereign’s dilemma: a coherent elite that could collectively strengthen the state could also overthrow the ruler. This dilemma emerged because strengthening state capacity and keeping rulers in power for longer required different social networks in which central elites were embedded. Wang examines how these social networks shaped the Chinese state, and vice versa, and he looks at how the ruler’s pursuit of power by fragmenting the elites became the final culprit for China’s fall. Drawing on more than a thousand years of Chinese history, The Rise and Fall of Imperial China highlights the role of elite social relations in influencing the trajectories of state development.

Download or read book Dwelling in the Archive written by Antoinette M. Burton and published by Oxford University Press, USA. This book was released on 2003 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Through an analysis of the writings of three 20th century Indian women, this book explores how the memoirs, fictions, and histories written by women can be read as counter-narratives of colonial modernity.