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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.
31

Identificação de funções de transferência de ordem fracionária utilizando como entrada um degrau

Jacyntho, Luiz Antonio [UNESP] 26 March 2015 (has links) (PDF)
Made available in DSpace on 2015-09-17T15:25:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-03-26. Added 1 bitstream(s) on 2015-09-17T15:46:31Z : No. of bitstreams: 1 000846232.pdf: 1582930 bytes, checksum: 0f47a8eb8c74c10c4b04a935d7bd5bd1 (MD5) / São propostos nesta tese novos métodos de identificação de sistemas lineares invariantes no tempo, descritos através de Funções de Transferência (FT), estáveis ou instáveis, de ordem fra- cionária, utilizando como entrada um degrau. A primeira contribuição aprimora o desempenho de um método de identificação conhecido, para FT de ordem inteira, com a otimização de um parâmetro durante a identificação. Posteriormente, é proposto um novo método, que utiliza in- tegradores de ordem fracionária, para a identificação de FT estáveis. Em seguida, propõe-se outro método que, além de utilizar integradores de ordem fracionária, faz uso de uma função exponencial convergente e também de um filtro, que combinados possibilitam a identificação de FT de ordem fracionária instáveis. Adicionalmente, um método ainda mais eficiente é pro- posto e o seu mecanismo de funcionamento baseia-se na resposta do sistema a uma entrada degrau, que multiplicada por diferentes exponenciais convergentes, gera um conjunto de sinais auxiliares para a obtenção do sinal final, necessário para identificar a FT, estável ou instável. Para comprovar a eficiência dos métodos propostos, foram realizadas várias identificações, com simulações numéricas, incluindo exemplos teóricos desenvolvidos no Matlab e experimentos práticos que foram realizados em laboratório, descritos a seguir: (i) função de transferência de um sistema de controle da posição de um carrinho acionado por um motor de corrente contí- nua; (ii) função de transferência relacionando a posição dos membros inferiores de pacientes hemiplégicos e paraplégicos sujeitos a uma estimulação elétrica funcional. Finalmente, é apre- sentada a identificação da função de transferência de uma rede RC tridimensional, que pode modelar circuitos para obter a resposta dielétrica de materiais compósitos contendo partículas... / This thesis proposes new methods for the identification of fractional order stable and unstable Transfer Functions (TF), based on the time response resulting from a single step excitation. Initially, the improvement of a known identification method for TF of integer order, considering the optimization of a parameter in the identification process, is presented. Then, a new method based on fractional order integrators, is proposed for the identification of stable TF. Moreover, another method for stable and unstable fractional order TF, also with fractional order integra- tors, that is based on the multiplication in the time domain of the plant output by a convergent exponential function and a suitable filter is proposed. Furthermore, a more efficient method is proposed, based on the multiplication in the time domain of the plant output by different conver- gent exponential functions and a suitable filter. Numerical examples using the Matlab software illustrate the theoretical results and are used for comparisons, including the following cases with experimental data: (i) TF of a control system for the position of a car using a DC motor; (ii) TF for of the leg position of paraplegic and hemiplegic patients subject to a functional electrical stimulation. Finally, the identification of a three-dimensional RC network, which can be used as circuit models for the dielectric response of composite materials containing insulating and conducting particles, is presented
32

Desenvolvimento de um regulador de pressão microprocessado / Development of a microprocessed pressure regulator

Leonardo de Lucena Martins 10 August 2012 (has links)
Dentre os fatores que afetam a uniformidade de aplicação de água, cita-se a variação de pressão no sistema, causada principalmente pela topografia do terreno e pela inexistência ou operação inadequada de reguladores de pressão. Nesse sentido, têm-se empregado válvulas reguladoras de pressão nos projetos de irrigação com variações topográficas. Contudo, a pressão de saída na válvula nem sempre será correspondente a apresentada no catálogo do fabricante. Com o avanço da eletrônica e a modernização da agricultura irrigada, justifica-se a busca para o aperfeiçoamento das técnicas de controle de pressão em sistemas de irrigação, visando à redução das perdas e o atendimento dos preceitos da irrigação sustentável. Portanto, a automação de reguladores de pressão deve torná-lo capaz de manter constante a pressão de saída, independente da pressão de entrada, além de possibilitar estabelecer a pressão de saída de acordo com as necessidades específicas de cada sistema de irrigação. De acordo com o que foi exposto, este trabalho teve como objetivo o desenvolvimento de um regulador de pressão microprocessado. O sistema de regulação desenvolvido foi composto por uma válvula hidráulica, um transdutor de pressão, duas válvulas solenóides, um aspersor e um circuito microprocessado. Baseado na leitura do transdutor de pressão de saída, o controlador eletrônico acionava as válvulas solenóides para pressurizar ou para aliviar o diafragma da válvula hidráulica. O tempo de abertura da válvula solenóide era função da pressão instantânea na tubulação. Avaliou-se o equipamento atuando até uma diferença entre pressão de entrada e de saída de 250 kPa. As pressões de entrada foram alteradas em intervalos de 49,03 kPa a cada 60 segundos, sendo estas avaliadas em um primeiro momento de forma crescente, e posteriormente de forma decrescente. As pressões de ajuste avaliadas foram de 98,06 kPa, 196,13 kPa, 294,19 kPa e 392,26 kPa. A faixa de vazão avaliada foi de 0,75 m3 h-1 a 3,74 m3 h-1, tendo o respectivo intervalo de velocidade de 0,42 m s-1 a 2,12 m s-1. Os resultados mostraram um tempo de ajuste entre 10 s e 20 s nos ensaios com pressão de entrada crescente e de 15 s e 30 s nos ensaios com pressão de entrada decrescente. Ao se avaliar a atuação do regulador eletrônico operando em toda a faixa de vazão estudada, verifica-se que este foi capaz de manter a pressão ajustada dentro dos limites aceitáveis ao valor estabelecido no dispositivo eletrônico, enquadrando-se, em um contexto geral, como controlador com nível de exatidão A (± 10% de desvio). Dessa forma, pode-se concluir que o controlador, operando nas condições definidas acima, apresentou um bom desempenho ao regular à pressão de saída. / The pressure variation is an important factor that affects the uniformity of water application in irrigation systems. This variation is caused by topography, the lack or improper operation of pressure regulators. Pressure regulating valves have been used in irrigation projects where there are problems of uneven topography. However, the output pressure on the valve will not be always corresponding to the manufacturer\'s catalog. Researches on techniques improvement for pressure controlling in irrigation systems are necessary to reduce losses in accordance with sustainable irrigation. The automation of pressure regulators must assure a constant outlet pressure independent of input pressure, and flexibility to set output pressures according to different conditions. Based on the previous content, the aim of this study was to develop a microprocessed pressure regulator. The developed system has a hydraulic valve, a pressure transducer, two solenoid valves, a sprinkler, and a microprocessed circuit. Based on data gathered from pressure transducer, the electronic controller triggered solenoid valves for pressurizing or relieving the hydraulic valve diaphragm. The opening time of the solenoid valve was a function of the instantaneous pressure in the pipe. We evaluated the operating equipment in a difference up to 250 kPa between input and output pressure. The inlet pressures were tested at intervals of 49.03 kPa every 60 seconds. We performed tests increasing and decreasing inlet pressure. The desired and evaluated output pressures were 98.06, 196.13, 294.19, and 392.26 kPa. The flow rate evaluated range was from 0.75 m3 h-1 to 3.74 m3 h-1, which the respective speed range was from 0.42 m s-1 to 2.12 m s-1. The results presented a required adjustment time between 10 to 20 seconds in tests with increasing inlet pressure, and from 15 to 30 seconds in tests with inlet pressure decreasing. The pressure regulator was able to maintain the preset output pressure within desired limits, when evaluating the performance of the electronic regulator operating in the flow range specified. Considering the results, the electronic developed device can be considered a controller that belongs in accuracy level A (± 10% deviation). Thus, we conclude that the controller was successful on controlling the output pressure, when operating under the conditions defined above.
33

Trest domácího vězení, jeho výkon a kontrola / House arrest, its execution and control

Suchomelová, Veronika January 2017 (has links)
The aim of this thesis is to give a comprehensive overview about the one of alternative sanction incorporated into the czech penal system with effect from 1 January 2010. The thesis devotes definition of general term "punishment", its help to better understanding of house arrest, the crux of this thesis. It aims to clarify the reasons for which legislator has decided to file this sanction to system of punishment, but also it aims to outline arguments standings against these procedure. The thesis also give a historical perspective about possibilities of using house arrest in the past. The primary aim of this thesis is focus on the current legislation of house arrest from the sight of substantive law and also procedural law. My attempt was describe several imperfections of legislation and propose the method to improve it alternatively. Part of the thesis devotes to Probation and mediation service considering to actually during of control the house arrest. Without this service the house arrest probably couldn't be ussed. The thesis is supplemented by probation officials opinions and by issues which they work with every day. With this matter also associate the provision of the act about electronic monitoring which still isn't in effect and actually situation of procurement to operator of electronic...
34

Diagnostika moderních řídících jednotek motorů / Diagnostics of modern car control units

Slíž, Martin January 2013 (has links)
The topic of this thesis is the design and implementation of an interface for communication with modern electronic control units of EDC group. The work is devoted to an introduction to the world of automotive diagnostics, analysis of communication protocols and rules for transmitting messages. The greater part is devoted to the analysis of the CAN bus belonging protocols. The outcome of this work is the design and implementation of a communication device for diagnostics of electronic control units of EDC group.
35

Bezdrátový sběr dat z řídících jednotek automobilů / Wireless data collection form engine control units

Procházka, Miroslav January 2013 (has links)
This thesis deals with implementation of a wireless interface for a module providing communication between computer and electronic control unit of an automobile. The 802.11 standard, wireless network structures and MAC sublayer were described. The thesis suggests selection of the most suitable WLAN module, testing of module's features used and the WLAN module implementation. Modifications for the next device version were developed and programs for device operation were implemented.
36

Návrh testovacího pracoviště pro automatizované testování elektronické řídicí jednotky / Design of test environment for automatic testing of eletronic control unit

Dalecký, Filip January 2015 (has links)
This master’s thesis deals with the design and implementation of part of test environment for automatic testing of electronic control unit in the production. The electronic control unit is manufactured by UNIS, a.s. and is used as a control and power electronics for the hydraulic unit. The theoretical part of the thesis deals with the development and automatic testing of electronics in the field of aerospace engineering. The practical part describes the proposed automatic test environment and implementation of testing software using hardware and software products by National Instruments. The main platforms used for software development are LabVIEW and TestStand. Created test environment is finally verified by testing several control units.
37

Nahrazení vazby elektronickým kontrolním systémem / Electronic control system as an alternative to custody

Homolová, Karolína January 2020 (has links)
Electronic control system as an alternative to custody Abstract In the framework of the criminal justice process, the scope of using technical means through electronic monitoring is worldwide very extended indeed, being applicated in all stages of criminal proceedings. Although the most frequent manner while analysing the electronic control is the house arrest or release from imprisonment by conditional parole, electronic monitoring system finds its purpose also in pre-trial detention. Arrest is intended to be an exceptional institute of criminal proceedings, only to be used as necessary and proportionate measure and in compliance with the presumption of innocence and the constitutional right to personal freedom. In accordance with this concept, it is necessary to consider all time in the duration of custody whether the reasons for pre-trial detention still last and whether it would not rather be replaced by some alternative. The first electronic monitoring permanent program was launched in Czech republic in September 2018, so we have only a few experiences in this field so far. The aim of this paper is to identify some best practices to enhance the effectiveness of electronic monitoring as an alternative to custody in the Czech legal order and also to propose an amendments to the legislation of this...
38

Trest domácího vězení, jeho výkon a kontrola / Punishment of house arrest, its execution and control

Šárka, Jakub January 2020 (has links)
Punishment of house arrest, its execution and control Abstract This thesis deals with the punishment of house arrest. It describes the legal regulation of this punishment, further evaluates the practice and draws attention to the shortcomings. The thesis first defines the Czech system of punishments imposed for criminal offenses and describes the position of the punishment of house arrest in this system and its relationship to other punishments. The thesis further analyzes the substantive legislation of the punishment of house arrest in the Criminal Code, explains the ambiguities in the regulation and tries to recommend changes that could benefit this regulation. Moreover, the thesis deals with the legal regulation of the conversion of a punishment of house arrest sentence into a custodial sentence, which occurs when the execution of the punishment of house arrest sentence is violated. In addition, it deals with the legal regulation of the conversion of other punishments into the punishment of house arrest, draws attention to its shortcomings and proposes changes. In addition to the substantive legislation, the work also describes the execution of punishment of house arrest and all related cases where the punishment of house arrest cannot be executed. Furthermore, in this work, two ways of control of the...
39

Trest domácího vězení, jeho výkon a kontrola / House arrest, its execution and control

Procházková, Aneta January 2019 (has links)
House arrest, its execution and control This thesis focuses on the punishment of house arrest and its position as an alternative punishment. Its aim is to provide a comprehensive view of this institute in a broader context, to reveal its advantages and disadvantages and to evaluate its development so far. Given one of the functions of house arrest as a substitute for imprisonment in particular, the work goes in this direction and evaluates this aspect from several possible perspectives. The assessment is then based on a comparison of the theoretical assumptions and results of the practice, which offers a comparison of the actual use of punishment and its likely development in the coming years, including de lege ferenda. The first part of the thesis is conceived as a general introduction which aims to introduce the concept of punishment, including its purpose, meaning and function. The following section than narrows the broad subject of punishment to alternative punishments, among which house arrest is included. One subchapter is also devoted to the concept of restorative justice as the cornerstone of alternative sanctioning. The second part of the thesis deals with the main topic and analyzes all the requirements of the house arrest. These chapters describe its development, meaning, purpose and...
40

Nonlinear algorithms for fast and robust control of electrical drives

Borojević, Dušan January 1986 (has links)
Several new nonlinear algorithms for speed control of electrical drives are developed. They are compared with the algorithms for integral-proportional (I-P) control, sliding mode control (SLM) and adaptive control which uses the torque and parameter observer. To achieve fast and robust response, all algorithms use very large gains. In a new, variable limit PI (VLPI) control algorithm, integrator windup is completely prevented by using a high gain, "variable dead zone" nonlinearity as a local feedback over the integrator. Recently proposed soft variable structure (SVS) control, derived by using the Liapunov direct method, is modified so that the algorithm can be implemented with only the output measurements. Proper operation is achieved for any value of the output variable. The new control is very robust, but exhibits a steady state error. Two versions of the adaptive PI (API) control algorithm are developed that have fast and robust transient response with zero steady state error. The SVS API version operates similarly as the modified SVS control, but does not have its drawbacks. The SLM API version operates like the SLM control during large transients, and like VLPI control when close to the steady state. The local stability of the control is proved using the "small gain theorem". Its global behavior is analyzed by describing functions. Very good operation of the SVS API speed control within the proportional position loop is demonstrated. Faster transient response is achieved by implementing the SLM adaptive proportional control in the position loop. The operation is the same as the operation of the SLM API control in the speed loop. Similarity between modified SVS control, and classical adaptive algorithms is shown. API control, All the algorithms are simulated and compared for twofold and tenfold changes in plant parameters. The experimental verification of the results for I-P control, SLM control, and modified SVS control, are presented. Theory of the new algorithms is general, such that the results are applicable to any SISO plant that can be stabilized. / Ph. D.

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