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  • 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

Desenvolvimento de um manipulador robótico cilíndrico acionado pneumaticamente

Allgayer, Renan Schmidt January 2011 (has links)
Este trabalho aborda o projeto de um manipulador robótico cilíndrico acionado pneumaticamente de baixo custo e com 5 graus de liberdade. Este robô está sendo desenvolvido para realizar operações de movimentação de peças que venham a substituir postos de trabalho com ambiente insalubre e/ou de ações repetitivas nas quais as exigências de precisão, velocidade e capacidade de carga sejam limitadas. Os requisitos de projeto foram obtidos por meio de uma pesquisa em uma fábrica de ferramentas manuais. É apresentada a proposta de uma estrutura mecânica para suprir parte significativa das necessidades usuais de movimentação de peças em indústrias manufatureiras e o seu correspondente modelo teórico dinâmico não-linear, considerando o equacionamento dos atuadores pneumáticos acoplados ao sistema mecânico. Finalmente, é apresentado o projeto de um controlador linear por meio da técnica de realimentação de estados, com os ganhos definidos pela alocação de pólos a partir de um modelo linearizado de 3ª ordem. Para validação do modelo teórico e do algorítmo de controle propostos são apresentadas simulações de movimentação ponto a ponto e seguimento de trajetória. Os resultados mostram que a precisão de posicionamento do efetuador final é adequada para as tarefas de manipulação. / This work proposes the design of a low cost cylindrical robotic manipulator actuated pneumatically with 5 degrees of freedom. This robot is being developed to perform manipulation of parts, aiming to replace tasks usually performed in unhealthy environment and/or repetitive actions in which the requirements of accuracy, speed and load capacity are limited. The project requirements were obtained through a research in a manual tools factory. It is proposed a geometry that is intended to meet a significant amount of the usual moving parts demands in manufacturing industries and its corresponding nonlinear dynamic theoretic model, considering the pneumatic actuators model coupled to the mechanical system. Finally, the application of a linear control-law based on the technique of state feedback with design made by pole assignment using a linearized model of 3rd order is described. For validation of the theoretic model and proposed control algorithm are presented simulations of point to point regulation problem and trajectory tracking. The results show that the positioning accuracy of the end effector is suitable for achieving the planned tasks.
12

Desenvolvimento de um manipulador robótico cilíndrico acionado pneumaticamente

Allgayer, Renan Schmidt January 2011 (has links)
Este trabalho aborda o projeto de um manipulador robótico cilíndrico acionado pneumaticamente de baixo custo e com 5 graus de liberdade. Este robô está sendo desenvolvido para realizar operações de movimentação de peças que venham a substituir postos de trabalho com ambiente insalubre e/ou de ações repetitivas nas quais as exigências de precisão, velocidade e capacidade de carga sejam limitadas. Os requisitos de projeto foram obtidos por meio de uma pesquisa em uma fábrica de ferramentas manuais. É apresentada a proposta de uma estrutura mecânica para suprir parte significativa das necessidades usuais de movimentação de peças em indústrias manufatureiras e o seu correspondente modelo teórico dinâmico não-linear, considerando o equacionamento dos atuadores pneumáticos acoplados ao sistema mecânico. Finalmente, é apresentado o projeto de um controlador linear por meio da técnica de realimentação de estados, com os ganhos definidos pela alocação de pólos a partir de um modelo linearizado de 3ª ordem. Para validação do modelo teórico e do algorítmo de controle propostos são apresentadas simulações de movimentação ponto a ponto e seguimento de trajetória. Os resultados mostram que a precisão de posicionamento do efetuador final é adequada para as tarefas de manipulação. / This work proposes the design of a low cost cylindrical robotic manipulator actuated pneumatically with 5 degrees of freedom. This robot is being developed to perform manipulation of parts, aiming to replace tasks usually performed in unhealthy environment and/or repetitive actions in which the requirements of accuracy, speed and load capacity are limited. The project requirements were obtained through a research in a manual tools factory. It is proposed a geometry that is intended to meet a significant amount of the usual moving parts demands in manufacturing industries and its corresponding nonlinear dynamic theoretic model, considering the pneumatic actuators model coupled to the mechanical system. Finally, the application of a linear control-law based on the technique of state feedback with design made by pole assignment using a linearized model of 3rd order is described. For validation of the theoretic model and proposed control algorithm are presented simulations of point to point regulation problem and trajectory tracking. The results show that the positioning accuracy of the end effector is suitable for achieving the planned tasks.
13

Low-Impact and Damped State Feedback Control of a Solar Sail on an Optimal Non-Keplerian Planet-Centered Orbit

Gero, Ryan Micah 26 August 2009 (has links)
No description available.
14

Finite-time partial stability, stabilization, semistabilization, and optimal feedback control

L'afflitto, Andrea 08 June 2015 (has links)
Asymptotic stability is a key notion of system stability for controlled dynamical systems as it guarantees that the system trajectories are bounded in a neighborhood of a given isolated equilibrium point and converge to this equilibrium over the infinite horizon. In some applications, however, asymptotic stability is not the appropriate notion of stability. For example, for systems with a continuum of equilibria, every neighborhood of an equilibrium contains another equilibrium and a nonisolated equilibrium cannot be asymptotically stable. Alternatively, in stabilization of spacecraft dynamics via gimballed gyroscopes, it is desirable to find state- and output-feedback control laws that guarantee partial-state stability of the closed-loop system, that is, stability with respect to part of the system state. Furthermore, we may additionally require finite-time stability of the closed-loop system, that is, convergence of the system's trajectories to a Lyapunov stable equilibrium in finite time. The Hamilton-Jacobi-Bellman optimal control framework provides necessary and sufficient conditions for the existence of state-feedback controllers that minimize a given performance measure and guarantee asymptotic stability of the closed-loop system. In this research, we provide extensions of the Hamilton-Jacobi-Bellman optimal control theory to develop state-feedback control laws that minimize nonlinear-nonquadratic performance criteria and guarantee semistability, partial-state stability, finite-time stability, and finite-time partial state stability of the closed-loop system.
15

Control Law Partitioning Applied To Beam And Ball System

Kocak, Elif 01 May 2008 (has links) (PDF)
In this thesis different control methods are applied to the beam and ball system. Test setup for the previous thesis is handled, circuit assemblies and hardware redesigned. As the system is controlled by the control law partitioning method by a computer, discrete time system model is created. The controllability and the observability of the system are analyzed and a nonlinear controller by using control law partitioning in other words computed torque is designed. State feedback control algorithm previously designed is repeated. In case of calculating the non measurable state variables two different reduced order observers are designed for these two different controllers, one for control law partitioning controller and the other for state-feedback controller. Two controller methods designed for the thesis study are tested in the computer environment using modeling and simulation tools (Also a different controller by using sliding mode controller is designed and tested in the computer environment using simulation tools). A controller software program is written for the designed controller algorithms and this software is tested on the test setup. It is observed that the system is stable when we apply either of the control algorithms.
16

Model trojfázové umělé sítě / Model of Three-phase Power Microgrid

Macík, Tomáš January 2020 (has links)
The Diploma thesis deals with control of three-phase active rectifier and a three-phase DC/AC converter. It also explains phase-locked loop principle. The theoretical part including first three chapters lists several control approaches to three phase active rectifier and three phase DC/AC converter. Described control approaches to the active rectifier are control in dq frame and control in dq UVW frame. Listed control approaches to the DC/AC converter include cascaded control structure and a full state feedback control. The practical part is divided into last three chapters and includes mathematical description of phase-locked loop principle, model of active rectifier controlled in dq frame and a model of DC/AC converter controlled both by a cascaded control and a full¬ state feedback. The models are created in Matlab Simulink.
17

Nonlinear observation and control of a lightweight robotic manipulator actuated by shape memory alloy (SMA) wires / Observation et commande non linéaire d'un manipulateur robotique léger actionné par des fils en alliage à mémoire de forme (SMA)

Quintanar Guzmán, Serket 07 June 2019 (has links)
Au cours de la dernière décennie, l’industrie des véhicules aériens sans pilote (UAV) a connu une croissance et une diversification immenses. De nos jours, nous trouvons des applications basées sur les drones dans un large éventail d’industries, telles que les infrastructures, l’agriculture, les transports, etc. Ce phénomène a suscité un intérêt croissant dans le domaine de la manipulation aérienne. La mise en œuvre de manipulateurs aériens dans l'industrie des UAV pourrait générer une augmentation significative du nombre d'applications possibles. Cependant, la restriction de la charge utile disponible est l’un des principaux inconvénients de cette approche. L'impossibilité d'équiper les drones de bras robotiques industriels puissants et habiles a suscité l'intérêt pour le développement de manipulateurs légers adaptés à ces applications. Dans le but de fournir une solution légère alternative aux manipulateurs aériens, cette thèse propose un bras robotique léger actionné par des fils en alliage à mémoire de forme (SMA). Bien que les fils SMA représentent une excellente alternative aux actionneurs conventionnels pour les applications légères, ils impliquent également une dynamique hautement non linéaire, ce qui les rend difficiles à contrôler. Cherchant à présenter une solution pour la tâche difficile de contrôler les fils SMA, ce travail étudie les conséquences et les avantages de la mise en œuvre des techniques de commande par retour d’état. L'objectif final de cette étude est la mise en œuvre expérimentale d'un contrôle à rétroaction d'état pour la régulation de la position du bras robotique léger proposé. Tout d'abord, un modèle mathématique basé sur un modèle physique du comportement des câbles SMA est développé et validé expérimentalement. Ce modèle décrit la dynamique du bras robotique léger proposé du point de vue de la mécatronique. Le bras robotique proposé est testé avec trois contrôleurs de retour de sortie pour le contrôle de position angulaire, à savoir un PID, un mode coulissant et une commande adaptative. Les contrôleurs sont testés dans une simulation MATLAB, puis mis en œuvre et testés expérimentalement selon différents scénarios. Ensuite, afin de réaliser la mise en œuvre expérimentale d’une technique de commande par retour d’état, un observateur d’état, à entrée inconnue, est développé. Premièrement, un modèle observable sans commutation avec une entrée inconnue est dérivé du modèle présenté précédemment. Ce modèle prend comme entrée inconnue le taux de fraction de martensite du modèle d'origine, ce qui permet d'éliminer les termes de commutation dans le modèle. Ensuite, un observateur, à entrées inconnues, basé sur le filtre de Kalman étendu et sur l’observateur à mode glissant est développé. Cet observateur permet l’estimation simultanée de l’état et des entrées inconnues. Les conditions suffisantes de convergence et de stabilité sont établies. L'observateur est testé dans une simulation MATLAB et validé expérimentalement dans différents scénarios. Enfin, une technique de commande par retour d’état est testée en simulation et implémentée de manière expérimentale pour le contrôle de position angulaire du bras robotique léger proposé. Elle est basée sur la résolution d’une équation de Riccati (SDRE). En conclusion, une analyse comparative quantitative et qualitative entre une approche de commande par retour de sortie et la une de commande par retour d’état mis en œuvre est effectuée selon plusieurs scénarios, y compris la régulation de position, le suivi de position et le suivi de charges utiles changeantes. / In the last decade, the industry of Unmanned Aerial Vehicles (UAV) has gone through immense growth and diversification. Nowadays, we find drone based applications in a wide range of industries, such as infrastructure, agriculture, transport, among others. This phenomenon has generated an increasing interest in the field of aerial manipulation. The implementation of aerial manipulators in the UAV industry could generate a significant increase in possible applications. However, the restriction on available payload is one of the main setbacks of this approach. The impossibility to equip UAVs with heavy dexterous industrial robotic arms has driven the interest in the development of lightweight manipulators suitable for these applications. In the pursuit of providing an alternative lightweight solution for the aerial manipulators, this thesis proposes a lightweight robotic arm actuated by Shape Memory Alloy (SMA) wires. Although SMA wires represent a great alternative to conventional actuators for lightweight applications, they also imply highly nonlinear dynamics, which makes them difficult to control. Seeking to present a solution for the challenging task of controlling SMA wires, this work investigates the implications and advantages of the implementation of state feedback control techniques. The final aim of this study is the experimental implementation of a state feedback control for position regulation of the proposed lightweight robotic arm. Firstly, a mathematical model based on a constitutive model of the SMA wire is developed and experimentally validated. This model describes the dynamics of the proposed lightweight robotic arm from a mechatronics perspective. The proposed robotic arm is tested with three output feedback controllers for angular position control, namely a PID, a Sliding Mode and an Adaptive Controller. The controllers are tested in a MATLAB simulation and finally implemented and experimentally tested in various different scenarios. Following, in order to perform the experimental implementation of a state feedback control technique, a state and unknown input observer is developed. First, a non-switching observable model with unknown input of the proposed robotic arm is derived from the model previously presented. This model takes the martensite fraction rate of the original model as an unknown input, making it possible to eliminate the switching terms in the model. Then, a state and unknown input observer is proposed. This observer is based on the Extended Kalman Filter (EKF) for state estimation and sliding mode approach for unknown input estimation. Sufficient conditions for stability and convergence are established. The observer is tested in a MATLAB simulation and experimentally validated in various different scenarios. Finally, a state feedback control technique is tested in simulation and experimentally implemented for angular position control of the proposed lightweight robotic arm. Specifically, continuous and discrete-time State-Dependent Riccati Equation (SDRE) control laws are derived and implemented. To conclude, a quantitative and qualitative comparative analysis between an output feedback control approach and the implemented state feedback control is carried out under multiple scenarios, including position regulation, position tracking and tracking with changing payloads.
18

Feedback Control for Maximizing Combustion Efficiency of a Combustion Burner System

Horning, Marcus 10 June 2016 (has links)
No description available.
19

Commande prédictive des systèmes hybrides et application à la commande de systèmes en électronique de puissance. / Predictive control of hybrid systems and its application to the control of power electronics systems

Vlad, Cristina 21 March 2013 (has links)
Actuellement la nécessité des systèmes d’alimentation d’énergie, capables d’assurer un fonctionnement stable dans des domaines de fonctionnement assez larges avec des bonnes performances dynamiques (rapidité du système, variations limitées de la tension de sortie en réponse aux perturbations de charge ou de tension d’alimentation), devient de plus en plus importante. De ce fait, cette thèse est orientée sur la commande des convertisseurs de puissance DC-DC représentés par des modèles hybrides.En tenant compte de la structure variable de ces systèmes à commutation, un modèle hybride permet de décrire plus précisément le comportement dynamique d’un convertisseur dans son domaine de fonctionnement. Dans cette optique, l’approximation PWA est utilisée afin de modéliser les convertisseurs DC-DC. A partir des modèles hybrides développés, on s’est intéressé à la stabilisation des convertisseurs au moyen des correcteurs à gains commutés élaborés sur la base de fonctions de Lyapunov PWQ, et à l’implantation d’une commande prédictive explicite, en considérant des contraintes sur l’entrée de commande. La méthode de modélisation et les stratégies de commande proposées ont été appliquées sur deux topologies : un convertisseur buck, afin de mieux maîtriser le réglage des correcteurs et un convertisseur flyback avec filtre d’entrée. Cette dernière topologie nous a permis de répondre aux difficultés du point de vue de la commande (comportement à déphasage non-minimal) rencontrées dans la majorité des convertisseurs DC-DC. Les performances des commandes élaborées ont été validées en simulation sur les topologies considérées et expérimentalement sur une maquette du convertisseur buck. / Lately, power supply systems, guaranteeing the global stability for large enough operation ranges with good dynamic performances (small settling time, bounded overshoot of the output voltage in the presence of load or supply voltage variations), are strongly needed. Therefore, this thesis deals with control problems of DC-DC power converters represented by hybrid models.Considering the variable structure of these switched systems, a hybrid model describes more precisely the converter’s dynamics in its operating domain. From this perspective, a PWA (piecewise affine) approximation is used in order to model the DC-DC converters. Based on the developed hybrid models, first we have designed a stable piecewise linear state-feedback controller using piecewise quadratic (PWQ) Lyapunov functions, and secondly, we have implemented an explicit predictive control law taking into account constraints on the control input. The hybrid modeling technique and the proposed control strategies were applied on two different topologies of converters: a buck converter, in order to have a thorough knowledge of the controllers’ tuning, and a flyback converter with an input filter. This last topology, allowed us to manage different control problems (non-minimum phase behavior) encountered in the majority of topologies of DC-DC power converters. The controllers’ performances were validated in simulation on both considered topologies and also experimentally on buck converter.
20

Contribution à la modélisation non-linéaire et à la commande d'un actionneur robotique intégré pour la manipulation / Non-linear modeling and control of a robotic actuator. Application to object manipulation

Huard, Benoît 07 June 2013 (has links)
La réalisation de tâches de manipulation dextres requiert une complexité aussi bien dans la conception de préhenseur robotique que dans la synthèse de leurs lois de commande. Une optimisation de la mécatronique de ces systèmes permet de répondre aux contraintes d'intégration fonctionnelle en se passant de capteurs de force terminaux. L'utilisation de mécanismes réversibles rend alors possible la détermination du positionnement du système dans l'espace libre et la détection de son interaction avec les objets manipulés, grâce aux mesures proprioceptives inhérentes aux actionneurs électriques. L'objectif de cette thèse est de parvenir synthétiser, dans le contexte articulaire (un degré-de-liberté), une commande adaptée à la manipulation en tenant compte de ces particularités mécaniques. La méthode proposée est basée sur une commande robuste par rapport aux non-linéarités structurelles dues aux effets gravitationnels et aux frottements secs d'une part et par rapport aux rigidités variables des objets manipulés. L'approche choisie nécessite la connaissance précise de la configuration du système étudié à chaque instant. Une représentation dynamique de son comportement permet de synthétiser un capteur logiciel pour l'estimation des grandeurs indispensables à la commande. Ces différentes étapes sont validées par des essais expérimentaux pour justifier la démarche choisie menant à une commande adaptée à la manipulation d'objets. / The realization of dexterous manipulation tasks requires a complexity in robotic hands design as well as in their control laws synthesis. A mecatronical optimization of these systems helps to answer for functional integration constraints by avoiding external force sensors. Back-drivable mechanics allows the free-space positioning determination of such system as far as the detection of its interaction with a manipulated object thanks to proprioceptives measures at electric actuator level. The objective of this thesis is to synthesize a control law adapted to object manipulation by taking into account these mechanical properties in a one degree-of-freedom case. The proposed method is based on a robust control according to structural non-linearities due to gravitational effects and dry frictions on the one hand and with regard to a variable rigidity of manipulated objects on the other hand. The chosen approach requires a precise knowledge of the system configuration at all time. A dynamic representation of its behavior enables a software sensor synthesis for the exteroceptives variables estimation in a control law application purpose. The different steps are experimentally validated in order to justify the chosen approach leading to object manipulation.

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