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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.
1

POSITION CONTROL OF A PNEUMATIC SYSTEM USING ADAPTIVE INTELLIGENT METHODS

Dehghan, Behrad 21 June 2012 (has links)
Behrad Dehghan: Position Control of a Pneumatic System using Adaptive Intelligent Methods. M.A.Sc. Thesis, Queen’s University, June, 2012. A large body of research is devoted to the development of advanced control techniques to improve the positioning performance of pneumatic systems, which are known to be highly nonlinear systems. Although model based controllers show good results, the requirement for a system model makes these methods difficult to implement. So-called intelligent algorithms, such as neural networks and fuzzy rule based controllers, are attractive since they do not require a model. The performance of these controllers can be enhanced by adding an adaptive mechanism to adjust controller parameters in a continuous on-line fashion. The objective of this thesis was to explore different adaptive intelligent controllers for position control of a pneumatic system. The application was the x-axis and z-axis of a pneumatic gantry robot. They were tested independently for their ability to track step and sine wave trajectories. The rodded x-axis cylinder was an example of a short stroke low friction application. The rodless z-axis cylinder was an example of a long stroke high friction application. Five different controllers were tested: 1) PID, 2) Fuzzy, 3) PID+Adaptive Neural Network Compensator (ANNC), 4) ANNonly and 5) Fuzzy Adaptive PID (FAPID). Results with FAPID and PID+ANNC showed improvement in tracking performance over PID by 60% for the rodded and 35% for the rodless cylinder. This level of improvement was expected given the adaptive nature of the controller. Unfortunately, both required significant effort to setup and tune. In order to reduce the tuning effort, a second adaptive mechanism was added to FAPID, to adjust output weights. Results with adaptive PID and modified FAPID (MFAPID) showed further improvement performance over PID by 87% for the rodded and 70% for the rodless cylinder (in addition to being easier to tune). To provide a measure of robustness, experiments were conducted at two supply pressures and three tracking frequencies. The fact that MFAPID was able to improve performance for both cylinders, is considered further evidence of its robustness. MFAPID is considered novel for two reasons: 1) fuzzy rule set is reduced in size relative previous work and 2) addition of an adaptive mechanism for output weights is new. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2012-06-20 11:09:19.694
2

Projeto e desenvolvimento de um sistema de controle para um dispositivo de ventilação mecânica pulmonar. / Project and development of a control system for a lung mechanical ventilation device.

Turrin, Bruno Bestle 20 September 2011 (has links)
A ventilação mecânica pulmonar é a substituição da respiração espontânea de um paciente quando este não realiza ou realiza parcialmente esta tarefa. Esta ventilação é de extrema importância para o tratamento de pacientes em estado crítico em unidades de terapia intensiva e para a manutenção da oxigenação sanguínea durante cirurgias. A ventilação mecânica pulmonar consiste em empurrar os gases para dentro do pulmão de forma controlada, mantendo uma pressão inspiratória ou um volume inspiratório determinado. Além disso, controla o nível de pressão durante a expiração do paciente para manter os alvéolos abertos e dificultar lesões internas. Este trabalho se propõe a caracterizar uma especificação de engenharia para os sistemas de controle de ventilação, se baseando em características fisiológicas do sistema respiratório do paciente saudável e também com patologias conhecidas. São apresentados modelos matemáticos para os sistemas mecânicos responsáveis pela atuação na inspiração e na expiração do paciente, bem como um modelo matemático para o sistema respiratório. Foram desenvolvidos sistemas de controle, baseados no controlador PID, para os principais tipos de modalidades ventilatórias. Os sistemas controlados foram simulados e os resultados são apresentados neste trabalho. Os controles propostos foram implementados em equipamentos de anestesia e UTI projetados na K. Takaoka Ind. Com. Prod. Hosp. LTDA. entre 2008 e 2010 no Brasil, e estão sendo usados hoje nas salas de cirurgia e centros de terapia intensiva pelo Brasil e em alguns países da América do Sul e do Oriente médio. / The mechanical ventilation is the replacement of spontaneous breathing of a patient when it does not perform or partially perform this task. This ventilation is extremely important for the treatment of critically ill patients in intensive care units and for the maintenance of blood oxygenation during surgery. The mechanical ventilation consists in pushing the gas into the lungs in a controlled manner, maintaining a determined inspiratory pressure or inspiratory volume. In addition, it has to control the pressure level during the patients exhalation to keep the alveoli opened and prevent internal injuries. This work aims to characterize an engineering specification for the control systems of ventilation, relying on physiological characteristics of the patient\'s respiratory system on healthy subjects and also subjects with known diseases. Here are presented mathematical models for the mechanical systems responsible for acting on the inspiration and expiration of the patient, as well as a mathematical model for the respiratory system. There were developed control systems, based on the PID controller for the main types of ventilation modes. Controlled systems were simulated and the results are presented in this dissertation. The proposed controls were implemented in anesthesia and intensive care equipments designed in K. Takaoka Ind. Com Prod. Hosp. LTD. between 2008 and 2010 in Brazil, and are being used today in the operating rooms and intensive care centers in Brazil and some countries in South America and the Middle East.
3

Projeto e desenvolvimento de um sistema de controle para um dispositivo de ventilação mecânica pulmonar. / Project and development of a control system for a lung mechanical ventilation device.

Bruno Bestle Turrin 20 September 2011 (has links)
A ventilação mecânica pulmonar é a substituição da respiração espontânea de um paciente quando este não realiza ou realiza parcialmente esta tarefa. Esta ventilação é de extrema importância para o tratamento de pacientes em estado crítico em unidades de terapia intensiva e para a manutenção da oxigenação sanguínea durante cirurgias. A ventilação mecânica pulmonar consiste em empurrar os gases para dentro do pulmão de forma controlada, mantendo uma pressão inspiratória ou um volume inspiratório determinado. Além disso, controla o nível de pressão durante a expiração do paciente para manter os alvéolos abertos e dificultar lesões internas. Este trabalho se propõe a caracterizar uma especificação de engenharia para os sistemas de controle de ventilação, se baseando em características fisiológicas do sistema respiratório do paciente saudável e também com patologias conhecidas. São apresentados modelos matemáticos para os sistemas mecânicos responsáveis pela atuação na inspiração e na expiração do paciente, bem como um modelo matemático para o sistema respiratório. Foram desenvolvidos sistemas de controle, baseados no controlador PID, para os principais tipos de modalidades ventilatórias. Os sistemas controlados foram simulados e os resultados são apresentados neste trabalho. Os controles propostos foram implementados em equipamentos de anestesia e UTI projetados na K. Takaoka Ind. Com. Prod. Hosp. LTDA. entre 2008 e 2010 no Brasil, e estão sendo usados hoje nas salas de cirurgia e centros de terapia intensiva pelo Brasil e em alguns países da América do Sul e do Oriente médio. / The mechanical ventilation is the replacement of spontaneous breathing of a patient when it does not perform or partially perform this task. This ventilation is extremely important for the treatment of critically ill patients in intensive care units and for the maintenance of blood oxygenation during surgery. The mechanical ventilation consists in pushing the gas into the lungs in a controlled manner, maintaining a determined inspiratory pressure or inspiratory volume. In addition, it has to control the pressure level during the patients exhalation to keep the alveoli opened and prevent internal injuries. This work aims to characterize an engineering specification for the control systems of ventilation, relying on physiological characteristics of the patient\'s respiratory system on healthy subjects and also subjects with known diseases. Here are presented mathematical models for the mechanical systems responsible for acting on the inspiration and expiration of the patient, as well as a mathematical model for the respiratory system. There were developed control systems, based on the PID controller for the main types of ventilation modes. Controlled systems were simulated and the results are presented in this dissertation. The proposed controls were implemented in anesthesia and intensive care equipments designed in K. Takaoka Ind. Com Prod. Hosp. LTD. between 2008 and 2010 in Brazil, and are being used today in the operating rooms and intensive care centers in Brazil and some countries in South America and the Middle East.
4

Design, modeling and control of inherently compliant actuators with a special consideration on agonist-anthropomorphic configuration / Conception, modélisation et contrôle d'actionneurs intrinsèquement conformes avec une considération spéciale sur la configuration anthropomorphe agoniste-antagoniste

Hari shankar lal das, Ganesh kumar 22 December 2016 (has links)
Conception, modélisation et contrôle des actionneurs intrinsèquement conformes avec une considération particulière sur la configuration anthropomorphe agoniste-antagoniste "La recherche vise à la conception, la modélisation et le contrôle des actionneurs intrinsèquement conformes pour les systèmes anthropomorphes.La première partie du travail se concentre sur l'étude de divers Existants et rechercher la possibilité d'autres actionneurs autres que les moteurs électriques conventionnels.Une attention particulière est accordée aux actionneurs souples à base de polymères élctroactifs qui ont un bon potentiel dans les futures applications robotiques. Parallèlement, on a synthétisé un modèle de la dynamique de l'actionneur et du contrôleur basé sur le modèle (MPC et contrôle optimal) pour un bras anthropomorphe 7 Dofs actionné par une paire antagoniste-agoniste de Muscles Artificiels Pneumatiques (PAM) à chaque articulation. Ce modèle et contrôleur est alors intégré dans l'environnement logiciel développé par l'équipe. En utilisant le bras manipulateur anthropomorphe basé sur PAM et le simulateur numérique, des tests sont effectués afin d'évaluer le potentiel de cet actionneur et de comparer avec les capacités du corps humain. / Design, modeling and control of inherently compliant actuators with a special consideration on agonist- antagonist anthropomorphic configuration" The research aims at the design, modeling and control of inherently compliant actuators for anthropomorphic systems. The first part of the work focuses on the study of various existing designs and look for the possibility of alternative actuators other than the conventional electric motors. Special attention is given to elctroactive polymer based soft actuators which have good potential in future robotic applications. In parallel, a model of the actuator dynamics and the model-based controller (MPC and optimal control) have been synthesized for an anthropomorphic 7 Dofs arm actuated by antagonist-agonist pair of Pneumatic Artificial Muscles (PAMs) at each joint. Such model and controller is then integrated within the software environment developed by the team. Using the PAMs based anthropomorphic manipulator arm and the numerical simulator, tests are done in order to evaluate the potential of this actuator and compare with the human body capabilities.

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