CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / This work describes the study and implementation of a hybrid control technique applied to the positioning of the rotor shaft in a three-phase induction motor (IM). The machine has been modeled using the field oriented control (FOC) strategy. In additional, it is used three controllers to obtain the design of the position loop, each one with different operating characteristics. Initially, two constant gain controllers are associated with the position loop diagram in the FOC technique in order to obtain a fastest response, with disturbance rejection and without overshoot. Therefore, it used a Proportional (P) controller based on Ziegler-Nichols tuning method so that a faster system response is achieved and a predictive control strategy called Generalized Predictive Control (GPC), based on Proportional â Integral controller tuning form, to smooth the overshoot caused by the P controller. Subsequently, seeking a more efficient performance of the position control in the IM, It used a control strategy based on fuzzy logic that takes into account the weighting of P and GPC controllers together. For purposes of validation, simulations and experimental results of the P, GPC and hybrid control strategies are presented. The simulation was set up in Matlab/Simulink and the experimental plant was implemented with a Digital Signal Controller (DSC), manufactured by Texas Instruments TMS320F2812. Analyzing the results, the Proportional demonstrated the fastest reference tracking, among the others techniques, with a settling time of 0.25 seconds, however with overshoot. The GPC controller presented a longer accommodation time, about 2 seconds and without overshoot. The application of the hybrid proposed technique combine the fast tracking reference of the P controller, about 1 second to reach the reference, and without overshoot as in the GPC controller results. Besides, the robust characteristic of both controllers was maintained in the hybridization proposed technique. / Este trabalho descreve o estudo e implementaÃÃo de uma tÃcnica de controle hÃbrida aplicada ao posicionamento do eixo de um motor de induÃÃo trifÃsico (MIT). O motor de induÃÃo foi modelado usando-se a estratÃgia de controle de campo orientado a fim de projetar para a malha de posiÃÃo trÃs controladores, cada um com diferentes caracterÃsticas de operaÃÃo. Neste caso, incorporou-se inicialmente à malha de posiÃÃo da estratÃgia de controle de campo orientado a aÃÃo de dois controladores de ganho constante com o objetivo de posicionar o eixo de forma rÃpida, com pouco sobressinal e com rejeiÃÃo à perturbaÃÃo. Desta forma, utilizou-se um controlador Proporcional (P) com sintonia baseada em Ziegler-Nichols de modo a se obter uma caracterÃstica mais rÃpida do sistema e, uma estratÃgia de controle preditivo denominada de GPC (Generalized Predictive Control) com o objetivo de suavizar a aÃÃo do controlador P em termos de elevado sobressinal considerando a sintonia do controlador GPC baseada em um controlador Proporcional-Integral (PI). Posteriormente, para se obter um desempenho mais eficiente do controle de posiÃÃo do MIT, utilizou-se uma estratÃgia de controle baseada em lÃgica fuzzy de modo a se levar em conta a ponderaÃÃo dos controladores P e GPC, conjuntamente. Para fins de validaÃÃo sÃo apresentados resultados da aplicaÃÃo das estratÃgias de controle P, GPC e hÃbrida no controle de posiÃÃo do MIT a partir de simulaÃÃes em ambiente Matlab/Simulink e atravÃs da implementaÃÃo do sistema de controle de posiÃÃo utilizando-se um processador digital de sinais, o DSP TMS320F2812 fabricado pela Texas Instruments. A partir dos resultados encontrados, o Proporcional demonstrou um rÃpido seguimento de referÃncia, dentre as tÃcnicas utilizadas, com tempo de acomodaÃÃo experimental de 0,25 segundos, porÃm com sobressinal. O controlador GPC apresentou um tempo de acomodaÃÃo maior, cerca de 2 segundos e sem sobressinal. A aplicaÃÃo da tÃcnica hÃbrida proposta conseguiu combinar o rÃpido seguimento de referÃncia do Proporcional, levando cerca de 1 segundo para alcanÃar a referÃncia, e sem sobressinal como o controlador GPC. AlÃm do que, como os controladores possuem uma caracterÃstica robusta tambÃm se garantiu essa propriedade para o hibridismo proposto.

Dans une optique de maximisation de la production et de réduction des coûts d’installation, de maintenance et d’entretien des trackers solaires, qui permettent d’orienter les modules photovoltaïques à haute concentration (HCPV), ces travaux de thèse se focalisent sur l’amélioration de la précision et la réduction du coût de la stratégie de génération de la trajectoire du tracker. Dans un premier temps, un simulateur de tracker HCPV est développé offrant une étude de l’influence de la performance du suivi du soleil sur la production des modules HCPV, permettant ainsi une étude et une comparaison des stratégies de génération de trajectoires. Le simulateur est basé sur un modèle comportemental de module HCPV monté sur tracker permettant de prédire la puissance maximale du module HCPV en fonction de l’erreur de position du tracker face au soleil, de l’ensoleillement direct et de la température. Une première stratégie de commande dite de référence a été implémentée sur ce simulateur. C’est une commande hybride qui repose sur un viseur solaire pour corriger l’erreur de poursuite par un calcul astronomique. Ensuite, afin d’améliorer les performances et de réduire les coûts de cette stratégie, une nouvelle approche sans capteur est développée en se basant sur une méthode d’optimisation du gradient de puissance pour la génération de la trajectoire du tracker. Une étude complémentaire est également exposée afin de mettre en évidence des algorithmes de recherche de la puissance maximale (MPPT) pouvant offrir des temps de réponse suffisamment rapides pour ne pas affecter la qualité de l’évaluation du gradient de puissance. Dans ce contexte, une commande MPPT P&O améliorée par un réseau de neurones à complexité réduite est proposée, assurant un compromis entre précision, simplicité et rapidité / This work focuses on improving the accuracy and on reducing the cost of the tracker generating trajectory strategy, in order to maximize the production and to reduce the installation and the maintenance cost of a solar tracker orienting high concentrated photovoltaic modules (HCPV). Initially, we propose a behavioral modeling of the HCPV module mounted on a dual axis tracker in order to study the influence of the tracking performance on the module power production. Then, this simulator can be used to test control strategies and to compare their performance. Firstly, a classical control strategy is implemented in the simulator. It is based on a hybrid control operating an astronomical calculation to follow the sun path, and a sun sensor to correct the tracking error. A sensorless strategy is proposed in this work to reduce the cost of the HCPV tracker control. This strategy is based on a gradient optimization algorithm to generate the tracker trajectory and to catch the sun path. Tested on the simulator, this strategy presents the same accuracy as the classical strategy while being less costly. The last study proposed in this thesis work concerns maximum power point tracking (MPPT) algorithms, in order to respond to a given problem relating to the practical implementation of gradient algorithm. In this context, we propose an original optimization of the P&O MPPT control with a neural network algorithm leading to a significant reduction of the computational cost required to train it. This approach, which is ensuring a good compromise between accuracy and complexity is sufficiently fast to not affect the quality of the evaluation of the gradient.

[pt] No presente trabalho estuda-se a aplicação do controle estrutural na proteção de estruturas submetidas a carregamentos dinâmicos contra níveis de vibração indesejáveis que possam causar desconforto e, até mesmo, comprometer a segurança e integridade da edificação. Os três tipos de controle estrutural, passivo, ativo e híbrido, são analisados de forma a evidenciar as vantagens do uso do controle híbrido. O mecanismo de controle utilizado é o denominado amortecedor de massa sintonizado (AMS), devido à sua vasta aplicação na Engenharia Civil, tendo uma grande quantidade sido instalada em edifícios, pontes e chaminés industriais para controle de vibrações causadas pelo vento. Verifica-se a influência da não- linearidade da rigidez do AMS no comportamento do sistema principal. A utilização de amortecedores de massa sintonizados múltiplos é também estudada como uma forma de vencer certas limitações quanto à robustez deste tipo de sistema e melhorar sua performance. Analisa-se por fim o comportamento e eficiência do amortecedor de massa híbrido (AMH), em relação ao AMS passivo. Para cálculo da força de controle são utilizados os seguintes algoritmos: controle ótimo linear clássico, controle ótimo instantâneo e controle ótimo não-linear. Uma estratégia para definição das matrizes de ponderação, utilizadas no algoritmo de controle ótimo instantâneo, que minimizem a amplitude da resposta harmônica permanente é apresentada. Exemplos numéricos são apresentados ao longo de todo o trabalho. Verifica-se que a utilização do controle híbrido é mais eficiente que os controles passivo e ativo isolados, requerendo forças de magnitude inferiores, o que reduz bastante o custo deste tipo de sistema. O sistema de controle híbrido se mostrou eficiente na redução de vibrações causadas por carregamentos cujas freqüências eram diversas das consideradas no projeto do sistema de controle passivo. Verificou-se, ainda que o mesmo se comportou de forma satisfatória no caso de discrepância na freqüência natural da estrutura. / [en] In this work the use of structural control is studied to protect dynamically loaded building structures against undesirable vibration levels, which can cause human discomfort and, even more, compromise the building safety and integrity. The three types of structural control, passive, ative and hybrid, are analysed to show the advantages of hybrid control in reducing undesirable vibration levels. The chosen control mechanism is the so called tuned mass damper (TMD), due to its large application in Civil Engineering, having a great number of these devices been installed in buildings, bridges and industrial chimneys to control structural vibrations induced by wind loads. It is also verified the influence of TMD non linear stiffness on the main system behaviour. The use of multiple tuned mass dampers is studied as a possible way of improving the TMD robustness and performance. The hybrid mass damper (HMD) behaviour and efficiency comparing to the passive mass damper is analysed in detail. To calculate the control force the following control algorithms are used: classical optimum linear control, instantaneous optimum control and non-linear optimum control. A strategy to define the weighting matrices used in the instantaneous optimum control algorithm that minimizes the harmonic response amplitude is presented. Several numerical examples are presented aalong the work. The results show that the hybrid control is more efficient that the passive or active control used separately, requiring smaller forces reducing in this way the cost of the control system. The hybrid control system showed to be more efficient in reducing vibrations caused by loadings which had different frequencies from that considered on the passive control design. Moreover it was shown that hybrid control has a satisfactory perfomance when discrepancies in natural frequency occur.

The master’s thesis deals with modelling of various architectures of hybrid powertrains for three vehicle sizes in GT-SUITE and compares them in daily commuting operating mode. On top of making of the hybrid vehicle simulation models, control algorithms had to be created to manage the energy split between the internal combustion engine and the electric motor for each of the architectures. Routes to work and back were logged using the GPS and postprocessed to obtain the speed and the road grade profiles. Resulting data was used as an input in simulations of daily commuting. To compare all hybrid powertrain architectures, fuel economy and electricity consumption were evaluated for WLTP and daily commuting operating modes. Finally, the environmental impact of each topology was assessed based on an estimation of corresponding well-to-wheel emissions.

This paper discusses the current and future drivetrain perspectives of powerful mobile machines, especially in regards to TCO and drive performance. For the TCO-impact, the power losses of the components plays a big role and, if they are designed for efficiency, they have a significant and measurable influence. From the braking function point of view, this paper demonstrates not only the advantages of a valve-based over a control algorithm based solution, but also its innovative development directions towards a more sophisticated engine speed controller with optimized heat conversion into the oil. Also for the drivetrain subsystems, innovative components are discussed, like the hybrid control, combining the benefits of a non-feedback and a displacement control in one single assembly, or the variable charge system for further reduced energy consumption of the overall drivetrain.

Nowadays, PEM fuel cell systems for passenger cars are always realized as hybrid systems. If the architecture of a hybrid system is given, then the dimensioning of the fuel cell and battery subsystems is crucial in terms of costs, dynamics, and driving behavior in general. In order to analyze these dependencies correctly, the ZBT fuel cell model was integrated into a fuel cell system and a full vehicle simulation. The subject of the investigation is the interaction of different drive cycles, which in part are very different, with differently dimensioned sub models for the fuel cell system and the battery. The ZBT fuel cell model is integrated into the simulation environment AVL CRUISE™ M for the fuel cell system and the vehicle. An analysis is presented that compares the different drive cycles and system dimensions and provides specific recommendations for different use cases.

[pt] Esta dissertação apresenta o desenvolvimento de um controle híbrido de um robô do tipo humanoide Atlas em regime de locomoção estática para a frente. Nos experimentos faz-se uso do ambiente de simulação Gazebo, que permite uma modelagem precisa do robô. O sistema desenvolvido é composto pela modelagem da mecânica do robô, incluindo as equações da dinâmica que permitem o controle das juntas por torque computado, e pela determinação das posições que as juntas devem assumir. Isto é realizado por agentes que utilizam o algoritmo de aprendizado por reforço Q-Learning aproximado para planejar a locomoção do robô. A definição do espaço de estados, que compõe cada agente, difere da cartesiana tradicional e é baseada no conceito de pontos cardeais para estabelecer as direções a serem seguidas até o objetivo e para evitar obstáculos. Esta definição permite o uso de um ambiente simulado reduzido para treinamento, fornecendo aos agentes um conhecimento prévio à aplicação no ambiente real e facilitando, em consequência, a convergência para uma ação dita ótima em poucas iterações. Utilizam-se, no total, três agentes: um para controlar o deslocamento do centro de massa enquanto as duas pernas estão apoiadas ao chão, e outros dois para manter o centro de massa dentro de uma área de tolerância de cada um dos pés na situação em que o robô estiver apoiado com apenas um dos pés no chão. O controle híbrido foi também concebido para reduzir as chances de queda do robô durante a caminhada mediante o uso de uma série de restrições, tanto pelo aprendizado por reforço como pelo modelo da cinemática do robô. A abordagem proposta permite um treinamento eficiente em poucas iterações, produz bons resultados e assegura a integridade do robô. / [en] This dissertation presents the development of a hybrid control for an Atlas humanoid robot moving forward in a static locomotion regime. The Gazebo simulation environment used in the experiments allows a precise modeling of the robot. The developed system consists of the robot mechanics modeling, including dynamical equations that allow the control of joints by computed-torque and the determination of positions the joints should take. This is accomplished by agents that make use of the approximate Q-Learning reinforcement learning algorithm to plan the robot s locomotion. The definition of the state space that makes up each agent differs from the traditional cartesian one and is based on the concept of cardinal points to establish the directions to be followed to the goal and avoid obstacles. This allows the use of a reduced simulated environment for training, providing the agents with prior knowledge to the application in a real environment and facilitating, as a result, convergence to a so-called optimal action in few iterations. Three agents are used: one to control the center of mass displacement when the two legs are poised on the floor and other two for keeping the center of mass within a tolerance range of each of the legs when only one foot is on the ground. In order to reduce the chance of the robot falling down while walking the hybrid control employs a number of constraints, both in the reinforcement learning part and in the robot kinematics model. The proposed approach allows an effective training in few iterations, achieves good results and ensures the integrity of the robot.

Der vorliegende Beitrag stellt einen Entwurf für eine flexible und robuste Steuerungsarchitektur für Roboter- und Fertigungssysteme vor. Dabei wurde versucht ein offenes Konzept zu realisieren, welches einen vereinfachten Engineeringprozess ermöglicht. Hierzu wird innerhalb der Steuerung eine Trennung zwischen einem funktionellen verhaltensbasierten und einem ablauforientierten Modell vorgeschlagen. Dieser Ansatz wird durch die Verwendung von Aktionsprimitiven innerhalb einer hybriden Robotersteuerung ermöglicht. Diese garantieren durch ihre ausgeprägte Modularität eine hohe Flexibilität und Erweiterbarkeit des entstandenen Systems. Im Beitrag wird sowohl der entstandene Entwurf diskutiert als auch eine prototypische objektorientierte Implementierung vorgestellt sowie erste Ergebnisse präsentiert. / This paper presents a framework for a flexible and robust control architecture for robotic systems. The design incorporates an application independent system concept which allows a simplified engineering process. For this purpose a distinction between a functional behavioural and a sequential control system model is proposed. This approach is based on the utilisation of action primitives within a hybrid control architecture. The use of these primitives affords a high level of modularity through increasing flexibility and expandability of the resulting system. In this paper the proposed framework will be discussed as well as a prototypical object-oriented implementation and first results.

In this dissertation, we present several main research thrusts involving thermodynamic stabilization via energy dissipating hybrid controllers and nonlinear control of network systems. Specifically, a novel class of fixed-order, energy-based hybrid controllers is presented as a means for achieving enhanced energy dissipation in Euler-Lagrange, lossless, and dissipative dynamical systems. These dynamic controllers combine a logical switching architecture with continuous dynamics to guarantee that the system plant energy is strictly decreasing across switching. In addition, we construct hybrid dynamic controllers that guarantee that the closed-loop system is consistent with basic thermodynamic principles. In particular, the existence of an entropy function for the closed-loop system is established that satisfies a hybrid Clausius-type inequality. Special cases of energy-based hybrid controllers involving state-dependent switching are described, and the framework is applied to aerospace system models. The overall framework demonstrates that energy-based hybrid resetting controllers provide an extremely efficient mechanism for dissipating energy in nonlinear dynamical systems. Next, we present finite-time coordination controllers for multiagent network systems. Recent technological advances in communications and computation have spurred a broad interest in autonomous, adaptable vehicle formations. Distributed decision-making for coordination of networks of dynamic agents addresses a broad area of applications including cooperative control of unmanned air vehicles, microsatellite clusters, mobile robotics, and congestion control in communication networks. In this part of the dissertation we focus on finite-time consensus protocols for networks of dynamic agents with undirected information flow. The proposed controller architectures are predicated on the recently developed notion of system thermodynamics resulting in thermodynamically consistent continuous controller architectures involving the exchange of information between agents that guarantee that the closed-loop dynamical network is consistent with basic thermodynamic principles.

Der vorliegende Beitrag stellt einen Entwurf für eine flexible und robuste Steuerungsarchitektur für Roboter- und Fertigungssysteme vor. Dabei wurde versucht ein offenes Konzept zu realisieren, welches einen vereinfachten Engineeringprozess ermöglicht. Hierzu wird innerhalb der Steuerung eine Trennung zwischen einem funktionellen verhaltensbasierten und einem ablauforientierten Modell vorgeschlagen. Dieser Ansatz wird durch die Verwendung von Aktionsprimitiven innerhalb einer hybriden Robotersteuerung ermöglicht. Diese garantieren durch ihre ausgeprägte Modularität eine hohe Flexibilität und Erweiterbarkeit des entstandenen Systems. Im Beitrag wird sowohl der entstandene Entwurf diskutiert als auch eine prototypische objektorientierte Implementierung vorgestellt sowie erste Ergebnisse präsentiert. / This paper presents a framework for a flexible and robust control architecture for robotic systems. The design incorporates an application independent system concept which allows a simplified engineering process. For this purpose a distinction between a functional behavioural and a sequential control system model is proposed. This approach is based on the utilisation of action primitives within a hybrid control architecture. The use of these primitives affords a high level of modularity through increasing flexibility and expandability of the resulting system. In this paper the proposed framework will be discussed as well as a prototypical object-oriented implementation and first results.