L'objectif principal de ce travail est de proposer des approches de commande performantes et robustes aux incertitudes pour les robots parallèles de type Delta, qui sont conçus pour effectuer des tâches industriels importantes et exigeantes comme l'emballage en agroalimentaire, la découpe laser, etc. Les difficultés les plus importantes pour garantir une bonne performance de suivi de trajectoires de ces manipulateurs pour les hautes accélérations avec la meilleure précision possible, tout en conservant de telle performance indépendamment des conditions d'opération (par exemple avec différentes conditions de charge, différentes trajectoires, etc.) sont leur actionnement couplé, l'augmentation de leurs dynamiques non-linéaires et le problème de vibrations mécaniques avec l'augmentation des accélérations envisagées, la présence d'incertitudes sur le modèle/environnement et la redondance d'actionnement si elle existe. Dans cette thèse, différentes approches de commande et observateurs d'état ont été proposés et implémentés expérimentalement sur deux robots de type Delta, à savoir le Par2 (non-redondant) et le R4 (à redondance d'actionnement). Pour le premier, une commande non linéaire/adaptative à mode Dual a été proposée en espace articulaire, synthétisé avec trois différents observateurs d'état pour la estimation des vitesses articulaires: un observateur lead-lag, un observateur Alpha-bêta-gamma et un observateur à grand gain. Pour le robot R4, un commande à feedforward en espace-dual avec a été proposée pour la compensation de sa dynamique (avec laquelle une aaccélération maximale de 100G a été atteinte), puis un contrôleur adaptatif dans l'espace-dual a été proposé afin de garantir une estimation et mise à jours automatique des paramètres du système en temps réel, garantissant ainsi sa bonne performance indépendamment du scénario expérimental. L'analyse de stabilité du robot Par2 bouclé avec la commande adaptative à Mode Dual et du robot R4 commandé avec le contrôleur adaptatif dans l'espace-dual sont fournies, des simulations ont été effectuées et les résultats expérimentaux confirment la bonne performance des approches de commande proposées. / The main objective of this work is to propose control strategies performant and robust towards uncertainties for Delta-like parallel robots, which are designed to perform important and demanding industrial tasks, such as packaging, laser cutting, etc. The most important difficulties to guarantee the good tracking performance of these manipulators for very high accelerations with the best possible precision, while maintaining such performance independently of the operational case (e.g. with different load conditions, different trajectories, etc.) are their coupled actuation, the increase of their high nonlinear dynamics and the problem of mechanical vibrations with the increase of the involved accelerations, the presence of uncertainties in the model/environment and the redundant actuation when applicable. In this thesis, different control schemes and state observers were proposed and experimentally implemented on two Delta-like robots, namely the Par2 (non-redundant) and the R4 (redundantly actuated) parallel manipulators. For the former, a nonlinear/adaptive Dual Mode controller was proposed in the joint space, complied with three different state observers for the estimation of joint velocities: a Lead-lag based observer, an Alpha-beta-gamma observer and the High-gain observer. For the latter, firstly a dual-space feedforward controller was proposed for the compensation of its dynamics (with which a maximum of 100G of acceleration was reached), then a dual-space adaptive controller was proposed in order to automatically estimate the parameters of the system in real-time, thus guaranteeing its good performance independently of the experimental scenario. The stability analysis of Par2 robot under the control of the Dual Mode controller and the R4 robot under the control of the dual-space adaptive controller are provided, simulations were performed and the experimental results confirm the good performance of the proposed control schemes.

Les robots humanoïdes sont en passe d'être commercialisés pour le public à grande échelle, mais pour réussir cet objectif il est nécessaire de rendre ces robots fiables, fonctionnels et sécurisés. Ceci implique de nombreuses améliorations par rapport à de l'état de l'art, pour permettre un produit fini. Un des domaines à améliorer est la commande corps-complet des robots humanoïdes. Les objectifs de cette thèse sont de proposer une architecture de commande permettant de générer des mouvements corps-complet bio-inspirés. L'idée principale étant de s'inspirer de la marche humaine afin de reproduire ces mouvements sur un robot humanoïde. La solution de commande proposée utilise le principe de tâches pour quatre objectifs cinématiques: (i) la pose relative des pieds, (ii) la position du CoM, (iii) l'orientation du buste, et (iv) l'évitement des butées articulaires. La stabilité est renforcée en modifiant la position du CoM désirée à l'aide d'un stabilisateur basé sur la régulation non linéaire du ZMP. L'approche résultante est appelée architecture de commande hybride cinématique/dynamique. Cette approche a été validée expérimentalement sur deux prototypes de robots humanoïdes pour différentes tâches telles que le squat et la marche. / Humanoid robots are a rising trend, and are about to be sold to the public on a large scale, but for this to be possible it is necessary to make them reliable, secure and functional. This implies many improvements over the prior state of the art. A domain of improvement is the full-body control of humanoid robots. The objective of this thesis is to propose a control architecture for generating a bio-inspired full-body control. The main idea is to learn from human walking to replicate these movements on a humanoid robot. The proposed control solution uses the principle of kinematics task for four objectives: (i) the relative pose of the feet, (ii) the position of the Centre de masse (CoM), (iii) the orientation of the upper-body, and (iv) the joints' limits avoidance. Stability is enhanced by modifiying the CoM position by using a stabilizer based on nonlinear regulation of the Zero Moment Point (ZMP). The resulting approach is called hybrid kinematic / dynamic control architecture. This approach has been validated experimentally on two prototypes of humanoid robots for tasks such as squat and walking.

" The chemical engineering literature is dominated by physical and (bio)-chemical processes that exhibit complex nonlinear behavior, and as a consequence, the associated requirements of their analysis, optimization, control and monitoring pose considerable challenges in the face of emerging competitive pressures on the chemical, petrochemical and pharmaceutical industries. The above operational requirements are now increasingly imposed on processes that exhibit inherently nonlinear behavior over a wide range of operating conditions, rendering the employment of linear process control and monitoring methods rather inadequate. At the same time, increased research efforts are now concentrated on the development of new process control and supervisory systems that could be digitally implemented with the aid of powerful computer software codes. In particular, it is widely recognized that the important objective of process performance reliability can be met through a comprehensive framework for process control and monitoring. From: (i) a process safety point of view, the more reliable the process control and monitoring scheme employed and the earlier the detection of an operationally hazardous problem, the greater the intervening power of the process engineering team to correct it and restore operational order (ii) a product quality point of view, the earlier detection of an operational problem might prevent the unnecessary production of o-spec products, and subsequently minimize cost. The present work proposes a new methodological perspective and a novel set of systematic analytical tools aiming at the synthesis and tuning of well-performing digital controllers and the development of monitoring algorithms for nonlinear processes. In particular, the main thematic and research axis traced are: (i) The systematic integrated synthesis and tuning of advanced model-based digital controllers using techniques conceptually inspired by Zubov’s advanced stability theory. (ii) The rigorous quantitative characterization and monitoring of the asymptotic behavior of complex nonlinear processes using the notion of invariant manifolds and functional equations theory. (iii) The systematic design of nonlinear state observer-based process monitoring systems to accurately reconstruct unmeasurable process variables in the presence of time-scale multiplicity. (iv) The design of robust nonlinear digital observers for chemical reaction systems in the presence of model uncertainty. "

The present research study is comprised of two main parts. The first part aims at the development of a systematic system-theoretic framework that allows the derivation of optimal chemotherapy protocols for HIV patients. The proposed framework is conceptually aligned with a notion of continuous-time model predictive control of nonlinear dynamical systems, and results in an optimal way to control viral replication, while maintaining low antiretroviral drug toxicity levels. This study is particularly important because it naturally integrates powerful system-theoretic techniques into a clinically challenging problem with worldwide implications, namely the one of developing chemotherapy patterns for HIV patients that are effective and do not induce adverse side-effects. The second part introduces a new digital controller design methodology for nonlinear (bio)chemical processes, that reflects contemporary necessities in the practical implementation of advanced process control strategies via digital computer-based algorithms. The proposed methodology relies on the derivation of an accurate sampled-data representation of the process, and the subsequent formulation and solution to a nonlinear digital controller synthesis problem. In particular, for the latter two distinct approaches are followed that are both based on the methodological principles of Lyapunov design and rely on a short-horizon model-based prediction and optimization of the rate of“energy dissipation" of the system, as it is realized through the time derivative of an appropriately selected Lyapunov function. First, the Lyapunov function is computed by solving the discrete Lyapunov matrix equation. In the second approach however, it is computed by solving a Zubov-like functional equation based on the system's drift vector field. Finally, two examples of a chemical and a biological reactor that both exhibit nonlinear behavior illustrate the main features of the proposed digital controller design method.

Le contrôle des écoulements est un domaine en forte croissance visant à modifier un écoulement à l’aide d’actionneurs et d’algorithmes de contrôle. Un axe important du contrôle des écoulements est le contrôle des décollements car le décollement de la couche limite provoque des augmentations de traînée et donc des pertes énergétiques et des coûts en carburant. Cette thèse vise à développer des algorithmes de contrôles pour le recollement des écoulements à l’aide de jets pulsés. La première partie de cette thèse expose une technique d’identification de modèle basée sur des données expérimentales. Les modèles sont déduits de considérations physiques et de l’Automatique. Ils offrent une bonne correspondance aux données tout en restant simple et en contenant peu de coefficients. La seconde partie de cette thèse utilise ces modèles pour élaborer deux algorithmes de contrôle : le premier est un contrôle optimal en boucle ouverte et le second un contrôle robuste en boucle fermée. Ces algorithmes ont été implémentés sur diverses maquettes expérimentales (LML, ONERA, LAMIH) et leurs propriétés a été testée expérimentalement. Les tests ont été réalisés en utilisant un Arduino Uno pour les mesures et le calcul du contrôle, ce qui montre que la méthode développée est simple à appliquer et requiert peu de puissance de calcul / Flow control is a strongly growing field aiming at modifying fluid flows using actuators and control algorithms. An important part of flow control is the control of flow separation as boundary layer separation increases drag and therefore energy losses and fuel consumption. This thesis focuses on developing control algorithms for flow reattachment using pulsed jets actuators. The first part of this work develops a model identification technique based on experimental data. The models are derived from physical and control theory considerations. They provide a good fit to the data while remaining simple and using few coefficients. The second part of this work uses this models in order to design two different control algorithms : the first one is an optimal feedforward control while the second one is a robust feedback control. The control algorithms have been applied on several experimental setups (LML, ONERA, LAMIH) and their properties have been experimentally tested. The tests were conducted using a simple Arduino Uno for the measurements and computation of the control, showing that the developed method is easy to apply and requires very few computational resources

Ces travaux de recherche portent sur la commande et la planification de trajectoires pour la navigation de véhicules autonomes. Ils se situent dans le cadre d'un projet très ambitieux lancé par le laboratoire Heudiasyc sur la conduite autonome à grande vitesses (vitesse longitudinale supérieure à 5m/s ~= 18 km/h). Pour proposer des solutions à cette problématique, après avoir réalisé une large recherche bibliographique sur la commande et la planification des trajectoires des véhicules autonomes, plusieurs contributions ont été présentées. En ce qui concerne la commande des véhicules autonomes, un contrôleur latéral par mode glissant d'ordre supérieur a été proposé. Compte tenu de la ressemblance implicite entre le mode glissant et le principe d'immersion et d'invariance (I&I), deux contrôleurs utilisant le principe d'immersion et d'invariance ont été proposés par la suite pour améliorer les performances par rapport au mode glissant. Le développement de ces nouveaux contrôleurs nous a permis de garantir une stabilité robuste pour tous les gains positifs des contrôleurs I&I. Ce résultat nous a conduit à étudier les propriétés intrinsèques du système. Une étude des propriétés de passivité du système a révélé des caractéristiques de passivité intéressantes. Par la suite, nous avons développé un contrôleur robuste basé sur la passivité. Concernant la navigation, nous avons développé deux algorithmes de navigation basés sur la méthode des tentacules. Ceci dans le but d'améliorer la méthode de base. Les résultats de la simulation montrent que les algorithmes donnent de bons résultats vis-à-vis des objectifs attendus d'évitement d'obstacles et de suivi de la trajectoire globale de référence. Les algorithmes de commande et de planification de trajectoires développés ont été validés en simulation hors-ligne avec des données réelles après avoir été testés sur un simulateur réaliste. / My research focuses on trajectory planning and control of autonomous vehicles. This work is a part of an extremely ambitious project launched by the Heudiasyc laboratory about autonomous driving at high speed (longitudinal speed greater to 5m/s ~= 18 km/h). With regard to the control of autonomous vehicles at high speed, a lateral controler using higher-order sliding mode control is proposed. Given the implicit similarity between the sliding mode and the principle of immersion and invariance, two controllers using the principle of immersion and invariance have been subsequently proposed in order to improve the performance with respect to the sliding mode. The development of these new controllers shows very strong robust stability which leads us to study the intrinsic properties of the system. A study of the passivity properties of the system is also crried out, showing some interesting characteristics of the system. Hence, a robust passivity-based controller has been developed. Regarding the navigation, we have developed two navigation algorithms based on the tentacles method. Subsequently, a feasibility study of trajectory generation strategies for high speed driving is conducted. The outcome of the simulation proved that the algorithms gave out good results with respect to the expected ogjectives of obstacle avoidance and global reference path following. Control and motion planning algorithms developed were validated offline by simulation with real data. They have been also tested on a realistic simulator.

Orientador: José Manoel Balthazar / Banca: Júlio Cesar Ruiz Claeyssen / Banca: Bento Rodrigues de Pontes Junior / Resumo: O propósito deste trabalho foi estudar as não linearidades na dinâmica de sistemas mecânicos e eletromecânicos. Entre eles inclui-se um corpo em levitação. As não linearidades levam o movimento da estrutura para o Efeito Sommerfeld. Por este fato, o trabalho do motor fica próximo ou na frequência de ressonância. Quando a estrutura atinge a condição de ressonância, a melhor parte da energia é consumida para gerar vibrações de grande amplitude sem nenhuma mudança sensível na frequência do motor. Neste trabalho, foi verificado o fenômeno para alguns sistemas não ideais inclusive o sistema com levitação magnética, discutindo uma forma de conduzir o sistema à condição de ressonância e evitar o "absorvedor de energia" que ocorre com o efeito Sommerfeld / Abstract: This paper studies the nonlinearities in dynamics of mechanics and electro mechanics non ideal systems. One of them is a magnetically levitated body. These nonlinearities lead the motion of the structure to the Sommerfeld Effect. For this reason the motor's near or in resonance frequency. When the structure achieves resonance condition, the best part of the energy is consumed to generate large amplitude vibration, with no sensitive change in the motor frequency. In this paper, is checked whether the phenomenon in some non ideal systems and also, if occurs with magnetic levitation. Will be discussed how to drive the system to ressonance condition and to avoid the "energy sink" that occurs with the Sommerfeld effect / Mestre

Este trabalho propÃe o estudo de uma nova topologia, com dois estÃgios, de um conversor estÃtico, onde existe um fluxo de potÃncia auxiliar com o objetivo de aumentar o rendimento do sistema. O primeiro estÃgio à um conversor CA-CC com correÃÃo do fator de potÃncia (PFC) e o segundo estÃgio à um conversor CC-CC isolado em alta frequÃncia. Os dois estÃgios do conversor proposto sÃo modelados por equaÃÃes diferenciais e atravÃs desses modelos sÃo desenvolvidas tÃcnicas de controle nÃo linear para o funcionamento dos conversores em malha fechada. A correÃÃo do fator de potÃncia do primeiro estÃgio à realizada pela tÃcnica de controle PBC (passivity-based control), enquanto que a tensÃo de saÃda do primeiro estÃgio à realizada pelo controle I&I (immersion and invariance). O segundo estÃgio necessita controlar somente a tensÃo de saÃda atravÃs do controle backstepping, por se tratar de um conversor CC-CC. / This work proposes a study of a new static converter topology with two stages, where the first is an AC-DC converter with PFC and the second is a DC-DC converter isolated in high-frequency. In addition, the static converter has a secondary power flow to achieve a better efficiency from the system. The two converterâs stages are modeled as differential equations, and through those models nonlinear control techniques are developed for close loop operation. The power-factor correction in the first stage is performed by the PBC (passivity-based control) control technique, while the output voltage from the first stage is performed by the I&I (immersion and invariance) control. As the second stage is a DC-DC converter, it only needs to control the output voltage, which is achieved through the backstepping control.

O TCSC é um dos compensadores dinâmicos mais eficazes empregados em Sistemas Elétricos de Potência, pois, oferece um ajuste flexível, de forma rápida e confiável, possibilitando a aplicação de teorias avançadas no seu controle. Estes dispositivos podem desempenhar funções importantes para a operação e o controle do sistema, trazendo inúmeros benefícios. Devido aos benefícios que o uso deste dispositivo oferece, uma grande quantidade de trabalhos vem sendo desenvolvidos com o intuito de sintetizar leis de controle para o mesmo. Porém, a maioria destes trabalhos é fundamentado em técnicas de controle clássico, isto é, projetando leis de controle baseado em sistemas linearizados e para pontos específicos da operação. Estas técnicas de análise entretanto, não garantem que para perturbações que levam o sistema para pontos distantes daqueles usados no projeto do controlador, a atuação do controlador seja eficaz e contribua assim para a estabilização do sistema. Visando o estudo mais aprofundado dos fenômenos que ocorrem nos sistemas físicos, modelos não lineares vêm sendo empregados, e as técnicas de projeto de controladores baseadas nesses modelos, são cada vez mais desenvolvidas. Neste trabalho será empregada a técnica de controle não linear baseada na Função Energia Generalizada de Controle para síntese de leis de controles estabilizantes para os dispositivos TCSC considerando, na modelagem, as perdas do sistema de transmissão. Esta técnica foi desenvolvida recentemente por SILVA et al. (2009), onde as ideias de Função de Lyapunov de Controle para uma classe maior de problemas foram desenvolvidas. Além de permitir o projeto do controlador, a técnica fornece estimativas da região de estabilidade do sistema e, portanto, podendo subsidiar a avaliação sistemática da contribuição do controlador na estabilidade transitória. / The TCSC is one of the most effective dynamic compensators used in electric power systems, offering a flexible adjustment, quickly and reliably, enabling the application of advanced theories in their control. These devices can play important roles for the operation and control of the networks, bringing many benefits. Because of the beneficial use of these devices a large amount of work has been developed in order to synthesize their control laws. However most of these studies are based on the classical control techniques, designing control laws based on linearized systems at specific operating points. However, these techniques do not guarantee that system disturbances which lead to operating points far away from those used for the controller design, the performance of the controller will be effective contributing to the system stabilization. Aiming to further studies and understanding of the physical phenomena occurring in the real world systems, nonlinear models have being employed in the controller design and techniques based on these methodologies have been proposed as never. In this work the technique of nonlinear control based on the Generalized Control Energy Function, for synthesis of control laws, which stabilize the TCSC devices considering the losses in the system transmission lines are employed. These techniques were recently developed by SILVA et al. (2009), and they extend the ideas of Control Lyapunov Function for a larger class of problems. Besides allowing the controller design, the technique provides estimates of the system stability region and therefore can support the systematic evaluation of the contribution to the transient stability controller.

No description available.