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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.
71

Compensação dos movimentos fisiológicos do coração em cirurgia robótica

Dill, Rafaela Brittes January 2013 (has links)
Esta dissertação refere-se `a simulação de um sistema de controle em um manipulador robótico para compensação dos movimentos do coração em cirurgias cardíacas minimamente invasivas. No intuito de compensar os movimentos do batimento cardíaco utilizam-se técnicas de controle híbrido de posição/força e dados dos movimentos do coração obtidos in vivo, utilizadas como elementos básicos para a constituição deste sistema. Tópicos de modelagem de manipuladores robóticos e, em especial, a modelagem da relação entre as forças e deslocamentos na superfície do coração compõe a base estrutural. Focalizou-se, ainda, o papel do controle de força em relação `a posição da ferramenta do manipulador na superfície do coração. Pretende-se que a principal contribuição deste trabalho seja demonstrar que o controlador híbrido segue as restrições impostas pela dinâmica do sistema coração-pulmão. / This paper refers to the simulation of a control system for a robotic manipulator to compensate the movements of the heart in minimally invasive cardiac surgery. In order to compensate the motion of the beating heart techniques are used to implement a hybrid position/force controller based on data and the movements of the heart obtained in vivo, used as references to the input of the system. Topics modeling robotic manipulators, and in particular, modeling the relationship between forces and displacements on the surface of the heart comprises the structural basis. The role of power control over the position of the manipulator tool on the surface of the heart. It is intended that the main contribution of this study is to show that the hybrid controller follows the restrictions imposed by the dynamics of the heart-lung system.
72

Controllerrollen / Controller role

Muharemovic, Mustafa, Kryh, Max January 2017 (has links)
The controller role was first used in the 1970s in Sweden, and since then the role hasundergone a lot of changes and development processes. Because of that the concept has beenmisused in several places and therefore the definition of a controller has become very unclear.The literature sees a controller as someone who works in the field of economics and hasduties in almost everything that economics means. The purpose of the essay is therefore togain an insight into the role of controller as well as to try to figure out the concept. To find outwhat a controller is working with, to explain and clarify the role of controller. Also comparingthe literature to the working world. During the course of the study the essay has followed anabductive approach with a qualitative research method. Six interviews with six controllershave been conducted, three of which are in the private sector and three in the public sector.The study has focused on four parts, the way the controller's career path looks, the role ofcontroller, what tasks the controller has and what personal qualities the controller has. Theoutcome of this is that the career path is in line with the literature, the controller role is not inline with the literature, the work tasks correspond to some extent with the literature, andpersonal characteristics are in part appropriate to the literature. / Controllerrollen började först användas under 70 – talet i Sverige, och sedan dess har rollengenomgått en hel del förändringar och utvecklingsprocesser. Det har i sin tur medfört ettbegrepp som på många ställen har urvattnats och därför har definitionen för en controllerblivit väldigt oklar. Litteraturen ser en controller som någon som arbetar inom huvudområdetekonomi och har arbetsuppgifter i nästan allt som ekonomi innebär. Uppsatsens syfte är därföratt få en inblick i rollen som controller samt att försöka reda ut begreppet. Att ta reda på vaden controller praktiskt arbetar med, att förklara och förtydliga rollen som controller. Även attjämföra arbetsrollen med litteraturen. Under studiens gång har uppsatsen följt en abduktivansats med en kvalitativ forskningsmetod. Sex stycken intervjuer med sex controllers harutförts, varav tre arbetar inom privat sektor och tre inom offentlig sektor. I studien har fokuslegat på fyra delar, hur karriärvägen för en controller ser ut, rollen som controller, vilkaarbetsuppgifter controllern har samt vilka personliga egenskaper controllern har. Utfallet avdetta är att karriärvägen stämmer överens med litteraturen, controllerrollen stämmer inte medlitteraturen, arbetsuppgifterna stämmer till viss del med litteraturen och personliga egenskaperstämmer till viss del med litteraturen.
73

Controllerns roll - från bean counter till affärspartner : En kvalitativ innehållsanalys av den svenska arbetsmarknaden för en controller

Henningsson, Mathilda, Klokic, Alisa January 2020 (has links)
Bakgrund och problemdiskussion: Allt eftersom verksamheter och ekonomistyrning utvecklas så utvecklas även controllerns roll. Controllern sägs ofta ha gått från att vara en bean counter till att vara en affärspartner men huruvida denna övergången har skett på den svenska marknaden råder det fortfarande stor oklarhet kring. Det finns även de som hävdar att endast en expansion av controllerns roll är aktuell i dagens läge. Denna tvetydighet är det som motiverar vidare studier av controllerns roll där efterfrågade arbetsuppgifter och egenskaper på den svenska marknaden idag studeras. Syfte: Syftet är att bringa klarhet i vad företag söker för egenskaper hos en controller och erbjuder för arbetsuppgifter i förhållande till vilken sektor organisationen verkar inom, offentlig eller privat, men även vilken storlek organisationen har. Studien ämnar bidra med kunskap om controllerns roll på dagens svenska arbetsmarknad. Metod: Studien utförs genom en kvalitativ innehållsanalys av samtliga jobbannonser publicerade på Arbetsförmedlingens tjänst Platsbanken funna med sökordet controller. Slutsats: Controllerns roll varierar beroende på vilken sektor verksamheten verkar inom och det är inte möjligt att tillskriva controllern en övergripande roll. På grund av komplexiteten i controllerns arbete 3 krävs det att controllern besitter olika roller. De främst förekommande rollerna för en controller är coach och analytiker men rollerna som kamrer och pedagog förekommer också. Nyckelord: Controller, bean counter, affärspartner, business controller, accounting controller, controllerns roll
74

Model-Free Controller Design based on Simultaneous Perturbation Stochastic Approximation / 同時摂動確率近似に基づくモデルフリー型制御器設計

Mohd, Ashraf bin Ahmad 23 March 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第19125号 / 情博第571号 / 新制||情||100(附属図書館) / 32076 / 京都大学大学院情報学研究科システム科学専攻 / (主査)教授 杉江 俊治, 教授 石井 信, 教授 加納 学, 准教授 東 俊一 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM
75

Development of a Neural PD Controller for Quad-rotors for Rejection of Wind Disturbances

Li, Jisheng January 2016 (has links)
No description available.
76

Desenvolvimento de um controlador ressonante-repetitivo aplicado a fontes de energia

Lorenzini, Charles January 2015 (has links)
Este trabalho apresenta um estudo de controladores repetitivos e ressonantes-repetitivos aplicados a fontes ininterruptas de energia (UPSs, do termo em inglês, Uninterruptible Power Supplies). Primeiramente, o desempenho dos controladores repetitivos é analisado a partir das exigências e dos procedimentos de testes definidos pela norma IEC 62040-3. A partir destes resultados, são discutidas as principais causas para o erro de seguimento de um sinal de referência e é avaliado o impacto de metodologias de correção aplicadas na função de transferência do controlador repetitivo. No contexto dos controladores ressonantes-repetitivos duas topologias são analisadas: a primeira é composta por um controlador ressonante sintonizado na frequência fundamental do sinal a ser seguido em paralelo com um controlador repetitivo sintonizado na mesma frequência; a segunda topologia é composta pelo mesmo paralelo entre os controladores ressonante e repetitivo, mas um filtro complementar é adicionado em série com o controlador repetitivo visando alocar a operação de cada controlador em faixas de frequências distintas. Então uma variação do controlador ressonante-repetitivo com filtro é proposta, na qual o filtro é utilizado para corrigir a fase do laço do controlador repetitivo e consequentemente aumentar a magnitude nas frequências de interesse. A partir desta estrutura proposta, uma representação no espaço de estados do sistema em malha fechada é obtida e o projeto do controlador é realizado através da solução de um problema de otimização com restrições na forma de Desigualdades Matriciais Lineares (do inglês, Linear Matrix Inequalities - LMIs). Resultados de simulação utilizando Matlab/PSIM são apresentados para demostrar a melhoria de desempenho do sistema com o controlador proposto. / This work presents a study of repetitive and resonant-repetitive controllers applied to Uninterruptible Power Supplies (UPSs). First, the performance of repetitive controllers is analyzed in terms of requirements and test procedures defined in the IEC 62040-3 standard. From these results the main causes of the reference tracking error are discussed and the impact of correction methodologies applied to repetitive controller transfer function is evaluated. In the context of the resonant-repetitive controllers two topologies are analyzed: the first is composed of a resonant controller tuned to the fundamental frequency of the signal to be followed in parallel with a repetitive controller tuned to the same frequency; the second topology is composed of the same parallel connection between the resonant and the repetitive controllers but a complementary filter is added in series with the repetitive controller aiming to restrict each controller action to different frequency bands. Then a variation of the resonant-repetitive controller with a filter is proposed, in which the filter is used to correct the phase of the repetitive controller loop and consequently increase the magnitude at the frequencies of interest. From this proposed structure, a state space model representing the closed loop system is obtained and the controller design is carried out by the solution of an optimization problem based on LMI (Linear Matrix Inequality) constraints. Simulation results in Matlab/PSIM are presented to demonstrate the improvement on system performance with the proposed controller.
77

Desenvolvimento de um controlador ressonante-repetitivo aplicado a fontes de energia

Lorenzini, Charles January 2015 (has links)
Este trabalho apresenta um estudo de controladores repetitivos e ressonantes-repetitivos aplicados a fontes ininterruptas de energia (UPSs, do termo em inglês, Uninterruptible Power Supplies). Primeiramente, o desempenho dos controladores repetitivos é analisado a partir das exigências e dos procedimentos de testes definidos pela norma IEC 62040-3. A partir destes resultados, são discutidas as principais causas para o erro de seguimento de um sinal de referência e é avaliado o impacto de metodologias de correção aplicadas na função de transferência do controlador repetitivo. No contexto dos controladores ressonantes-repetitivos duas topologias são analisadas: a primeira é composta por um controlador ressonante sintonizado na frequência fundamental do sinal a ser seguido em paralelo com um controlador repetitivo sintonizado na mesma frequência; a segunda topologia é composta pelo mesmo paralelo entre os controladores ressonante e repetitivo, mas um filtro complementar é adicionado em série com o controlador repetitivo visando alocar a operação de cada controlador em faixas de frequências distintas. Então uma variação do controlador ressonante-repetitivo com filtro é proposta, na qual o filtro é utilizado para corrigir a fase do laço do controlador repetitivo e consequentemente aumentar a magnitude nas frequências de interesse. A partir desta estrutura proposta, uma representação no espaço de estados do sistema em malha fechada é obtida e o projeto do controlador é realizado através da solução de um problema de otimização com restrições na forma de Desigualdades Matriciais Lineares (do inglês, Linear Matrix Inequalities - LMIs). Resultados de simulação utilizando Matlab/PSIM são apresentados para demostrar a melhoria de desempenho do sistema com o controlador proposto. / This work presents a study of repetitive and resonant-repetitive controllers applied to Uninterruptible Power Supplies (UPSs). First, the performance of repetitive controllers is analyzed in terms of requirements and test procedures defined in the IEC 62040-3 standard. From these results the main causes of the reference tracking error are discussed and the impact of correction methodologies applied to repetitive controller transfer function is evaluated. In the context of the resonant-repetitive controllers two topologies are analyzed: the first is composed of a resonant controller tuned to the fundamental frequency of the signal to be followed in parallel with a repetitive controller tuned to the same frequency; the second topology is composed of the same parallel connection between the resonant and the repetitive controllers but a complementary filter is added in series with the repetitive controller aiming to restrict each controller action to different frequency bands. Then a variation of the resonant-repetitive controller with a filter is proposed, in which the filter is used to correct the phase of the repetitive controller loop and consequently increase the magnitude at the frequencies of interest. From this proposed structure, a state space model representing the closed loop system is obtained and the controller design is carried out by the solution of an optimization problem based on LMI (Linear Matrix Inequality) constraints. Simulation results in Matlab/PSIM are presented to demonstrate the improvement on system performance with the proposed controller.
78

Desenvolvimento de um controlador ressonante-repetitivo aplicado a fontes de energia

Lorenzini, Charles January 2015 (has links)
Este trabalho apresenta um estudo de controladores repetitivos e ressonantes-repetitivos aplicados a fontes ininterruptas de energia (UPSs, do termo em inglês, Uninterruptible Power Supplies). Primeiramente, o desempenho dos controladores repetitivos é analisado a partir das exigências e dos procedimentos de testes definidos pela norma IEC 62040-3. A partir destes resultados, são discutidas as principais causas para o erro de seguimento de um sinal de referência e é avaliado o impacto de metodologias de correção aplicadas na função de transferência do controlador repetitivo. No contexto dos controladores ressonantes-repetitivos duas topologias são analisadas: a primeira é composta por um controlador ressonante sintonizado na frequência fundamental do sinal a ser seguido em paralelo com um controlador repetitivo sintonizado na mesma frequência; a segunda topologia é composta pelo mesmo paralelo entre os controladores ressonante e repetitivo, mas um filtro complementar é adicionado em série com o controlador repetitivo visando alocar a operação de cada controlador em faixas de frequências distintas. Então uma variação do controlador ressonante-repetitivo com filtro é proposta, na qual o filtro é utilizado para corrigir a fase do laço do controlador repetitivo e consequentemente aumentar a magnitude nas frequências de interesse. A partir desta estrutura proposta, uma representação no espaço de estados do sistema em malha fechada é obtida e o projeto do controlador é realizado através da solução de um problema de otimização com restrições na forma de Desigualdades Matriciais Lineares (do inglês, Linear Matrix Inequalities - LMIs). Resultados de simulação utilizando Matlab/PSIM são apresentados para demostrar a melhoria de desempenho do sistema com o controlador proposto. / This work presents a study of repetitive and resonant-repetitive controllers applied to Uninterruptible Power Supplies (UPSs). First, the performance of repetitive controllers is analyzed in terms of requirements and test procedures defined in the IEC 62040-3 standard. From these results the main causes of the reference tracking error are discussed and the impact of correction methodologies applied to repetitive controller transfer function is evaluated. In the context of the resonant-repetitive controllers two topologies are analyzed: the first is composed of a resonant controller tuned to the fundamental frequency of the signal to be followed in parallel with a repetitive controller tuned to the same frequency; the second topology is composed of the same parallel connection between the resonant and the repetitive controllers but a complementary filter is added in series with the repetitive controller aiming to restrict each controller action to different frequency bands. Then a variation of the resonant-repetitive controller with a filter is proposed, in which the filter is used to correct the phase of the repetitive controller loop and consequently increase the magnitude at the frequencies of interest. From this proposed structure, a state space model representing the closed loop system is obtained and the controller design is carried out by the solution of an optimization problem based on LMI (Linear Matrix Inequality) constraints. Simulation results in Matlab/PSIM are presented to demonstrate the improvement on system performance with the proposed controller.
79

TCP/AQM Congestion Control Based on the H2/H∞ Theory

Haghighizadeh, Navin January 2016 (has links)
This thesis uses a modern control approach to address the Internet traffic control issues in the Transport Layer. Through literature review, we are interested in using the H2/H∞ formulation to obtain the good transient performance of an H2 controller and the good robust property from an H∞ controller while avoiding their deficiencies. The H2/H∞ controller is designed by formulating an optimization problem using the H2-norm and the H∞-norm of the system, which can be solved by an LMI approach using MATLAB. Our design starts with the modeling of a router and the control system by augmenting the network plant function with the Sensitivity function S, the Complementary Sensitivity function T and the Input Sensitivity function U. These sensitivity functions along with their weight functions are used to monitor the closed-loop dynamics of the traffic control. By choosing different combinations of the sensitivity functions, we can obtain the SU, the ST and the STU controllers. Both the window-based and rate-based version of these different types of H2/H∞ controllers have been designed and investigated. We have also proved that these controllers are stable using Lyapunov’s First Method. Next, we verify the performance of the controllers by OPNET simulation using different performance measures of queue length, throughput, queueing delay, packet loss rate and goodput. Our performance evaluation via simulation has demonstrated the robustness and the better transient response such as the rise/fall time and the peak queue value. We have also investigated the controller performances subject to network dynamics as well as through comparison with other controllers. Finally, we have improved these controllers for real-time application. They are capable to update/renew the controller in a short time whenever new network parameter values are detected so that the optimum performance can be maintained.
80

New ways to interact with devices to change the gaming experience

Jankowski, Kim January 2020 (has links)
Gaming experience refers to the players’ overall experience when playing agame. Both game and controller have an impact on it. This project exploreshow different element arrangements on a controller can affect the players’gaming experience. Four lo-fi prototypes were constructed and used to bothtest the reaction of players, but also to educate them into the possibleelements included in controllers. Participants were then invited to designtheir own controller while reflecting about aspects like embodiment,immersion, or latency. Throughout the whole process participants reportedabout their previous experiences with controllers through an interview. Theresearch showed that the elemental arrangements did in fact affect theplayers’ gaming experience but also that there is a cultural understanding ofgames and controllers that constrains the possibility of new designs. Theproject also explored the limitations of conducting research on distance, andreflects about how remote design can be conducted.

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