Orientador: Marconi Kolm Madrid / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-10T09:28:57Z (GMT). No. of bitstreams: 1 Monteiro_DionneCavalcante_D.pdf: 1351119 bytes, checksum: e13d3adc10bf45c4ea22d6ef1b5a7117 (MD5) Previous issue date: 2003 / Resumo: Neste trabalho os algoritmos genéticos e as redes neurais artificiais, técnicas de inteligência artificial, são empregadas para algumas das tarefas que podem ser realizadas por um braço de robô. Inicialmente os algoritmos genéticos são empregados para o controle de trajetória de um robô em um espaço de trabalho que possui a presença de um obstáculo. Operações como crossover e mutação são apresentadas, principalmente por estar-se tratando de trajetórias que são formadas por segmentos de retas. As redes neurais artificiais são testadas no controle direto de dois processos reais usados como paradigma: uma mesa XY e um pêndulo invertido acionado. Para tais processos, é utilizada uma estrutura bastante simplificada, onde a rede neural artificial fornece um ganho para o controlador proporcional que calcula o sinal de controle a ser aplicado. O erro do processo serve para treinar a rede neural sem ser considerado nenhum tipo de treinamento anterior, ou seja, todo o controle neural é executado em tempo real, além disso, uma função determina a taxa de aprendizagem do algoritmo back-propagation em função dos erro existentes nas malhas de controle dos processos. Como existem diversas variáveis para tais controladores neurais, foi também considerado que não existia a possibilidade de se definir o melhor controlador para um determinado processo. Para resolver tal problema, um algoritmo genético foi utilizado para designar qual o melhor controlador para um determinado espaço de trabalho no qual o número de neurônios das camadas de entrada e escondida, constantes de configuração do controlador, e a topologia da rede são otimizados dentro do espaço considerado pelo algoritmo. Todos os resultados importantes obtidos são mostrados, visando mostrar que as técnicas de inteligência artificial podem ser aplicadas à robótica com a vantagem de diminuir, principalmente, o tempo de planejamento de tarefas, tais como: planejamento de trajetória, rastreamento de trajetória, e projeto de controladores eficientes / Abstract: In this work genetic algorithms and artificial neural networks are used for robot arm tasks. Initially, the genetic algorithms are employed to control the trajectory of a robot arm in a limited workspace with an obstacle. Operations like crossover and mutation are presented to manipulate trajectories determined by line segments. Artificial neural networks are tested to control two realtime processes: a XY-Table and an inverted pendulum. For these processes, it is used a simple structured control where the neural network provides a gain to the proportional control, generating a control signal to the processes. The process error is used for training a neural network, without any kind of off-line training, i.e., the training of the neural network is in realtime. Also, a function determines the learning rate of the back-propagation algorithms as a function of the errors of the process control. Since the neural controller have multiple variables, it was not possible to define an optimal controller for the processes. To solve this problem, a genetic algorithm was used to determine the best neural controller in the workspace used, where the number of neurons in the input and hidden layers, constants to configure the neural controller and the network topology are optimized. The results obtained show that artificial intelligent techniques can be applied to robotics reducing the time of task planning, like: trajectory planning, track planning and the project of efficient controllers / Doutorado / Engenharia de Computação / Doutor em Engenharia Elétrica

Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós-Graduação em Engenharia Oceânica, Escola de Engenharia, 2011. / Submitted by Lilian M. Silva (lilianmadeirasilva@hotmail.com) on 2013-04-22T19:33:16Z No. of bitstreams: 1 Modelagem e controle de atuadores robóticos e veículos subaquáticos não tripulados.pdf: 2108153 bytes, checksum: 01646a2e791884ffca750c5291ce8bd1 (MD5) / Approved for entry into archive by Bruna Vieira(bruninha_vieira@ibest.com.br) on 2013-06-03T19:14:00Z (GMT) No. of bitstreams: 1 Modelagem e controle de atuadores robóticos e veículos subaquáticos não tripulados.pdf: 2108153 bytes, checksum: 01646a2e791884ffca750c5291ce8bd1 (MD5) / Made available in DSpace on 2013-06-03T19:14:00Z (GMT). No. of bitstreams: 1 Modelagem e controle de atuadores robóticos e veículos subaquáticos não tripulados.pdf: 2108153 bytes, checksum: 01646a2e791884ffca750c5291ce8bd1 (MD5) Previous issue date: 2011 / Esta dissertação trata da modelagem e do controle de um atuador robótico e de veículos subaquáticos não tripulados. Primeiramente o trabalho compara e valida experimentalmente dois modelos de atrito existentes na literatura (LuGre e Gomes). Desenvolve-se um controle de posição baseado em estrutura variável para o atuador robótico do tipo harmonic-drive. Simulações são realizadas a fim de verificar a robustez do controlador perante a variação paramétrica em comparação com o controle proporcional, integral e derivativo (PID). Resultados experimentais das aplicações dos controles são obtidos mostrando desempenhos muito próximos aos de simulação. Posteriormente é feito um estudo sobre veículos subaquáticos não tripulados (Tatuí e Nerov). A modelagem cinemática é descrita por ângulos de Euler e a modelagem dinâmica inclui a interação da estrutura mecânica do veículo com o meio aquático e a ação dos propulsores. Desenvolve-se um sistema de controle de posição e orientação utilizando estrutura variável. Resultados de simulação ilustram as características do controlador com incertezas paramétricas e correntes oceânicas em comparação com o PID usando a estratégia de linearização por realimentação. / The subject of this dissertation is the modeling and control of a robotic actuator and also of unmanned underwater vehicles. Firstly, it compares and experimentally validates two friction models (LuGre and Gomes). A position control based on a variable structure is developed for the harmonic-drive type of robotic actuator. Simulations are performed to verify the robustness of the controller against the parametric variation and to compare to the proportional, integral and derivative control (PID). Experiments then show results similar to those from simulations. Later, we a study about unmanned underwater vehicles (Tatuí and Nerov) is presented. The kinematics modeling is described by Euler’s angles. The dynamics modeling includes the interaction of the vehicle’s mechanical structure with the aquatic environment and the actuation of the propellers. By using a variable structure, a position and orientation control system is developed. The simulation results then show the characteristics of the controler with parametric uncertainties and ocean streams, and compares them with those from a PID controler with feedback linearization.

This thesis deals with the determination of the position of the solenoid core in real time based on the measured current. The reference position of the current is used for feedback control of the solenoid. For this issue, software tool Matlab/Simulink was used. For current and temperature measurements, PCB circuits were created. The whole project was carried out on the dSPACE platform.

The thesis deals with design and implementation of proportional hydraulic valve, which will be integrated to hydraulic system of small hydro in Rájec - Jestřebí. This valve will be used to control one of the wicket gates of double Francis turbine. The thesis is processed for the company Mavel a.s., which is the owner of SH. The goal of this thesis is to create control of the valve according to the client's requirements, its implementation to the control system and commissioning.

Pour des applications depositionnement, les moteurs piézoélectriquesprésentent aujourd’hui une alternativeintéressante aux moteurs électromagnétiquesclassiques en raison de leur forte précision del’ordre de quelques nanomètres ainsi que de leurfaible niveau de bruit électromagnétique. Dansce contexte, les travaux de cette thèse portent surla modélisation, la conception, et l’implantationen temps réel de contrôleurs en position pour desmoteurs piézoélectriques. L’objectif est deproposer un système de contrôle en positionrobuste pour des applications robotiques avecun cahier des charges prédéfini. Trois moteurspiézoélectriques avec des principes defonctionnement différents (USR60, PAD7220,N-310.13) ont été choisis. Leurs modèlesélectromécaniques ont été développés afin devalider leurs principes de fonctionnement etd’analyser leurs comportements dynamiquesface à des perturbations (variation de couple decharge, de température, etc…). Ensuite, cesmodèles sont utilisés pour simuler et valider lesperformances des algorithmes de contrôle enboucle fermée notamment en termes deprécision, de robustesse et de stabilité. Desbancs de test expérimentaux ont été mis enœuvre pour les trois moteurs, et des modèlesréduits reliant les positions des moteurs auxsignaux de commande correspondants ont étéidentifiés expérimentalement. Deux contrôleursde position de type H-infini (H∞) et RST sontensuite synthétisés et simulés. Ces contrôleurssont implantés en temps réel sur les bancs detests expérimentaux via un système dSPACE.Les performances de chaque moteur associé à sacommande sont évaluées. Une étudecomparative entre les résultats expérimentauxde ces deux contrôleurs et ceux d’un contrôleurPID classique est aussi présentée. / The Piezoelectric motors present aninteresting alternative to electromagneticsmotors for precise positioning systems. This ismainly due to their high accuracy in thenanometer scale, and to their very lowelectromagnetic noise levels. In this context, thework presented in this thesis deals with themodeling, design, and real time implementationof position controllers for piezoelectric motors.The objective is to propose robust closed loopposition controller of piezoelectric motors forrobotic applications. Based on the applicationspecification requirements, three motors withdifferent topologies (USR60, PAD7220, N-310.10) are selected. Their electro mechanicmodels are developed in order to validate theiroperating principle and to analyze theirdynamics.These models are also used to simulate thecontroller algorithms in closed loop.Experimental platforms based on the threemotors are designed, and the reduced modelslinking the motor positions to the correspondingcontrol signals are experimentally identified.Afterwards, two position controllers of type Hinfinity(H∞) and RST are synthesized andsimulated. These controllers are implemented inreal time via the experimental platformsequipped by dSPACE boards. The performancesof each motor in closed loop associated to theposition controllers are evaluated using theexperimental results. Comparative studybetween the experimental results of twoproposed controllers and conventional PIDcontroller is also presented.Université Paris-

No description available.

Combining the advantages from electric motor and the pneumatic actuator, the hybrid pneumatic-electric actuator is expected to be safe, low-cost, clean, high power to weight ratio, and to provide precise position control. In this thesis, the modeling and control of an improved hybrid pneumatic-electric actuator prototype is presented. The actuator’s main components consist of a low-friction pneumatic cylinder, two on/off solenoid valves, and a small DC motor. The cylinder and motor are connected to a common output shaft using gears. The shaft rotates a single-link robot arm. Its position is measured by an incremental encoder. The prototype was improved by incorporating faster switching valves, flow controls, a faster valve drive circuit, a high resolution encoder rather than the existing linear potentiometer, more accurate pressure sensors and stronger gears. A system dynamic model without the valve dynamic was developed identified and validated using open-loop experiments. The valve models for a discrete input and PWM input were then developed and validated separately. The use of bipolynomial function and artificial neural network fitting methods for modeling the valve mass flow rates were compared. The combined system model with valve dynamics was validated experimentally. Two model-based nonlinear position controllers, using the backstepping and discrete-valued model predictive control (DVMPC) methods, were designed, simulated and extensively tested. Testing was done with the actuator operating using the cylinder alone, the motor alone and in hybrid mode using the cylinder and motor together. Operating in the hybrid mode reduced the root-mean-square error (RMSE) up to 80%. A stability analysis for the backstepping control including the valve modeling error, friction model error, and electric motor torque modeling error was performed. Compensation terms were designed to improve the performance for the two controllers. Additional stability analyses were performed for backstepping controller with a feedback term and the DVMPC with motor control. A payload estimation algorithm was proposed and shown to enhance the robustness of the DVMPC operating in vertical configuration. Simulations and experiments demonstrated that the model-based controllers performed well for both vertical and horizontal configurations. Regarding robustness to payload mismatch, if the payload was within the load capacity of the hybrid actuator, the model-based controllers were both insensitive to the payload variations in horizontal configuration. The backstepping controller was also robust to the payload variations in the vertical configuration. In experiments, the backstepping control in hybrid actuation mode produced a RMSE of 0.0066 radian for a 2 Hz sine wave desired position trajectory with a 0.3 radian amplitude. With DVMPC, this value decreased to 0.0045 radian. These tracking errors were shown to be 30 to 50% less than those produced by a modified linear position plus velocity plus acceleration controller. / Master of Applied Science (MASc)

Résumé The presented work addresses the issue of the double-tracking nature of a dominant position in European competition law. The aim of the integration efforts during the establishment of the EU was the creation of an internal market, especially the customs union. In order to achieve this state, it was necessary to take a number of integration measures and create a legal framework, i.e. conditions, under which economic competition in the internal market could operate effectively. In this context a variety of legislation valid for the whole EU territory has been accepted. However, in the context of the economic competition this work analyzes the legislation on market dominance carried out first in Article 102 of TFEU (Treaty on the Functioning of the European Union) prohibiting restrictive business practices in the form of abuse of a dominant position and also in Council Regulation (EEC) No 4064/89 and later in Council Regulation (EC) No 139/2004 regulating the control of concentrations between undertakings. In case of both the legislations the crucial question is the "dominant position" of an enterprise in the market, while Article 102 of TFEU represents the ex post control, i.e. applies only to the possible abuse of the dominant position, and in this sense the dominant position itself is not the...

Nessa pesquisa é apresentada uma inovação tecnológica em aplicações de controle de posição em máquinas e/ou dispositivos: o Controlador de Posição Linear Hidro- Pneumático. Para os casos nos quais têm-se grandes esforços combinados com pequenos deslocamentos, normalmente esse trabalho é feito com o uso de Sistemas Servo-Hidráulcos nos quais, devido às características mencionadas do nicho de mercado visado pela presente proposta, representam um custo elevado quando comparado com a solução Hidro-Pneumática aqui descrita. Salienta-se a simplicidade da infra-estrutura requerida para a instalação dessa alternativa, e também a redução do desperdício energético com relação à tecnologia tradicional com a Servo-Hidráulica. Observou-se nos testes com o protótipo, um excelente desempenho do sistema em termos de rapidez de resposta, como ainda no quesito resolução de posicionamento cujos valores encontrados apresentam-se na casa de 0,05 segundos e 0,01 mm, respectivamente. O pequeno tamanho físico obtido com essa nova tecnologia é outro item relevante, permitindo-se o seu emprego em locais de reduzido espaço disponível. . Resultados de simulações numéricas e de testes experimentais são apresentadas, bem como perspectivas de desenvolvimentos futuros. / This research presents a technological innovation for applications in machine / device position control: the Hydro-Pneumatic Linear Position controller. In cases where great efforts are combined with small dislocations, this task is normally accomplished by means of Servo Hydraulic Systems that, due to particular characteristics of the market envisaged by the present proposition, represent elevated costs, when compared to those of the hydro-pneumatic solution described here. This work presents an analytical numerical model for the devise as well as an experimental prototype. It worth noting the infra-structure simplicity required for this alternative implementation, and also the reduction in energy waste when compared to the traditional servo-hydraulic technology. The prototype experimental tests demonstrated the system excellent behavior in what concerns answer speed and position resolution whose values were respectively in range 0.05 s and 0,01 mm. The small physical size obtained with this technology is another relevant item, which allows the device use in places of reduced available space. Numerical simulation and experimental test results are presented as well as perspectives of future developments

For a wide range of people with limited upper- and lower-body mobility, interaction with robots remains a challenging problem. Due to various health conditions, they are often unable to use standard joystick interface, most of wheelchairs are equipped with. To accommodate this audience, a number of alternative human-machine interfaces have been designed, such as single switch, sip-and-puff, brain-computer interfaces. They are known as low throughput interfaces referring to the amount of information that an operator can pass into the machine. Using them to control a wheelchair poses a number of challenges. This thesis makes several contributions towards the design of robotic wheelchairs controlled via low throughput human-machine interfaces: (1) To improve wheelchair motion control, an adaptive controller with online parameter estimation is developed for a differentially driven wheelchair. (2) Steering control scheme is designed that provides a unified framework integrating different types of low throughput human-machine interfaces with an obstacle avoidance mechanism. (3) A novel approach to the design of control systems with low throughput human-machine interfaces has been proposed. Based on the approach, position control scheme for a holonomic robot that aims to probabilistically minimize time to destination is developed and tested in simulation. The scheme is adopted for a real differentially driven wheelchair. In contrast to other methods, the proposed scheme allows to use prior information about the user habits, but does not restrict navigation to a set of pre-defined points, and parallelizes the inference and motion reducing the navigation time. (4) To enable the real time operation of the position control, a high-performance algorithm for single-source any-angle path planning on a grid has been developed. By abandoning the graph model and introducing discrete geometric primitives to represent the propagating wave front, we were able to design a planning algorithm that uses only integer addition and bit shifting. Experiments revealed a significant performance advantage. Several modifications, including optimal and multithreaded implementations, are also presented.