909 resultados para Adaptive control systems
Resumo:
Nesta pesquisa, o que se pretendeu foi conhecer o atual estágio dos sistemas de controle gerencial utilizados em cinco hotéis localizados no Estado do Espírito Santo, levando-se em conta as peculiaridades do ramo e suas características com relação à adaptação, se necessário, dos diversos conceitos já aplicados em outros tipos de atividades, notadamente no ramo de serviços. Para tanto, procedeu-se a uma revisão de literatura e dos fundamentos teóricos sobre controle gerencial, principalmente aqueles voltados para a ciência comportamental, que serviram de suporte para estabelecer o plano de referência utilizado nesta pesquisa. Por tratar-se de trabalho descritivo, com riqueza de detalhes, foi adotada a metodologia do estudo de caso por ser a mais aconselhável neste tipo de trabalho. Entrevistas, utilizando questionários que continham em sua maior parte perguntas abertas, possibilitaram descrever o processo de controle gerencial existente nos hotéis pesquisados. Os resultados obtidos permitiram análises sobre a natureza deles e o estudo dos sistemas de controle gerencial dos hotéis estudados. Finalmente, uma comparaçao entre os resultados obtidos no trabalho de campo e os fundamentos teóricos levantados na revisão da literatura possibilitaram se chegasse a algumas conclusões importantes, além de permitirem formular algumas recomendações e sugestões para futuras pesquisas.
Resumo:
Esta pesquisa tentou estabelecer, através de um estudo exploratório, as comparações relevantes entre o sistema de controle gerencial implantado em um banco estatal brasileiro e a literatura sobre Controle Gerencial . Para isso, foi feita uma revisão da literatura e dos fundamentos teóricos existentes na teoria de Controle Gerencial, principalmente aqueles abordados na Ciência Comportamental . Como resultado dessa revisão foi estabelecido um plano de referência que foi utilizado nesta pesquisa. O estudo de caso foi a metodologia adotada no trabalho e as razões de seu uso sao apresentadas, bem como são discutidos os procedimentos empregados na pesquisa de campo,além das limitações desse tipo de estudo. Entrevistas, utilizando questionários com a maioria de questões abertas, permitiram descrever o processo de controle gerencial em uso pelo banco pesquisado. Os resultados obtidos possibilitaram análises sobre a natureza deles e o estado do sistema de controle , gerencial da empresa estudada. Finalmente, uma comparação entre os resultados da pesquisa de campo e a literatura revista possibilitou chegar a algumas conclusões importantes relativas a suas relações bem como permitiu que se levántassem questões para o Governo Federal e para o banco pesquisado. Também foram feitas algumas Sugestões para novos estudos.
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Para possibilitar o atendimento de demandas crescentes, e a cada dia mais complexas da sociedade, as organizações públicas necessitam utilizar ferramentas que permitam a condução de suas instituições a determinadas direções, buscando-se a melhoria dos serviços públicos e a redução do desperdício. Nesse cenário, o planejamento estratégico se mostra imprescindível, no entanto, não basta a sua formulação, esse tem que ser efetivamente implementado, permeando os demais processos da organização. Assim, este trabalho investigou a integração entre o planejamento estratégico e os sistemas gerenciais das organizações, em especial o orçamentário, que possui elevada relevância no setor público. O objetivo dessa pesquisa é identificar quais os fatores que influenciam a relação entre o planejamento estratégico e o processo de elaboração orçamentária nas organizações. Para tal, foi utilizada metodologia qualitativa, por meio de um estudo de caso múltiplo, que analisou quatro organizações da Marinha do Brasil. Os resultados da pesquisa permitiram o levantamento de diversos fatores, assim como os impactos causados por esses na relação estudada. No entanto, poucos fatores se apresentam da mesma forma nas organizações militares, havendo grande heterogeneidade não só entre as organizações, como também entre os setores de cada organização. Além disso, verifica-se que a implementação do planejamento estratégico, assim como de outras ferramentas administrativas que o fortalecem, encontra-se em plena evolução na Marinha, havendo tendência de fortalecimento do pensamento estratégico nessa Força nos próximos anos.
Resumo:
Investigar como as controladorias gerais municipais vêm se estruturando dentro do sistema político subnacional e identificar as similaridades e diferenças entre tais organizações são os principais objetivos deste trabalho. Tais atividades tornam-se relevantes a partir da constatação de que, apesar de ser cada vez mais frequente a alteração do nome e da estrutura do órgão central dos sistemas de controle interno subnacionais para controladorias gerais, não há uma regulamentação específica que predetermine os padrões institucionais, as funcionalidades organizacionais ou os escopos de atuação desses órgãos públicos. Cumpriu-se essa tarefa por meio das seguintes ações: (i) realização de pesquisa bibliográfica a partir da produção acadêmica dos cursos de pós-graduação em Administração Pública e Contabilidade (com ênfase no estudo de controladorias) no último triênio da CAPES (2010-2012); (ii) catalogação e análise dos instrumentos legais de institucionalização dos órgãos de controle interno nas capitais brasileiras; (iii) execução de análise organizacional comparada nas estruturas das controladorias-gerais encontradas. As pesquisas feitas constataram que a produção acadêmica da área de Administração Pública sobre o tema ainda é incipiente; que uma maior integração do campo técnico com diferentes campos acadêmicos (Administração Pública, Contabilidade, Ciência Política, Direito e Sociologia) se faz necessária; que, para além do processo de disseminação da esfera federal para local, há diversas bases estruturantes que influenciam o padrão adotado pelas controladorias públicas municipais; e que, enfim, não se pode falar em consolidação de um único formato institucional de controladoria mas, sim, de práticas constituídas conforme as diferentes conjunturas locais.
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It is very relevant, for academic or for society purposes as a whole the subject "corruption", a recurring problem that plagues companies and Governments in various parts of the world. Many recent cases draw attention to this topic, but one in particular, the case of corruption of the company Siemens AG, that resulted in the payment of the largest fines in the history on your model, based on the terms of the FCPA since it became law in 1977. This event caters specifically to the objective of this work which is to make an analysis based on agency theory and the codes of good practices of corporate governance on how large companies revising their corporate management systems and practices aiming at the recovery of its institutional image after significant impact on the company, such as the corruption scandal in which Siemens was involved. For this study, we opted for qualitative research as a methodological path contemplating the single case study. In the process of data collection were used data obtained through documentary research about the corruption scandal on public collection available in the internet. Open conversations were made with 3 compliance Department officials of Siemens for the purposes of understanding the case with. At the end of this work, it was observed in the Siemens turnaround process a correlation between what was proposed by the Agency Theory about internal control Systems based on what was accomplished by the company when promoted an extensive restructuring of the Department of compliance and corporate governance system, the improvement of internal controls, as well as the creation of detection tools , control, analysis and prevention of fraud, which were used to minimize the effects generated by the conflict of interest covered by the theory of Agency. KEY WORDS: Corporate Governance; Compliance; Corruption; Turnaround, Agency Theory
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A self-flotator vibrational prototype electromechanical drive for treatment of oil and water emulsion or like emulsion is presented and evaluated. Oil production and refining to obtain derivatives is carried out under arrangements technically referred to as on-shore and off-shore, ie, on the continent and in the sea. In Brazil 80 % of the petroleum production is taken at sea and area of deployment and it cost scale are worrisome. It is associated, oily water production on a large scale, carrier 95% of the potential pollutant of activity whose final destination is the environment medium, terrestrial or maritime. Although diversified set of techniques and water treatment systems are in use or research, we propose an innovative system that operates in a sustainable way without chemical additives, for the good of the ecosystem. Labyrinth adsor-bent is used in metal spirals, and laboratory scale flow. Equipment and process patents are claimed. Treatments were performed at different flow rates and bands often monitored with control systems, some built, other bought for this purpose. Measurements of the levels of oil and grease (OGC) of efluents treaty remained within the range of legal framework under test conditions. Adsorbents were weighed before and after treatment for obtaining oil impregna-tion, the performance goal of vibratory action and treatment as a whole. Treatment technolo-gies in course are referenced, to compare performance, qualitatively and quantitatively. The vibration energy consumption is faced with and without conventional flotation and self-flotation. There are good prospects for the proposed, especially in reducing the residence time, by capillary action system. The impregnation dimensionless parameter was created and confronted with consecrated dimensionless parameters, on the vibrational version, such as Weber number and Froude number in quadratic form, referred to as vibrational criticality. Re-sults suggest limits to the vibration intensity
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O presente trabalho teve por objetivo avaliar os efeitos do consórcio alho e cenoura em quatro épocas de semeadura de cenoura e em três manejos de plantas daninhas, visando determinar os benefícios do consórcio em relação ao controle destas plantas, à produtividade, à rentabilidade e à sua qualidade comercial. Testaram-se quatro épocas de semeadura da cenoura (0, 15, 30 e 45 dias após o plantio do alho), combinadas a três manejos de plantas daninhas (com herbicida, sem controle e com capinas freqüentes). Utilizou-se o delineamento de blocos casualizados dispostos em parcelas subdivididas, com a época de semeadura da cenoura sendo parcela e o sistema de manejo, a sub-parcela, em quatro repetições. O oxadiazon a 750 g ha-1 não foi tóxico às plantas de alho nem às de cenoura. A rentabilidade do consórcio alho e cenoura foi vantajosa em relação ao monocultivo de alho, principalmente dentro do manejo com capinas freqüentes.
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In this thesis, it is developed the robustness and stability analysis of a variable structure model reference adaptive controller considering the presence of disturbances and unmodeled dynamics. The controller is applied to uncertain, monovariable, linear time-invariant plants with relative degree one, and its development is based on the indirect adaptive control. In the direct approach, well known in the literature, the switching laws are designed for the controller parameters. In the indirect one, they are designed for the plant parameters and, thus, the selection of the relays upper bounds becomes more intuitive, whereas they are related to physical parameters, which present uncertainties that can be known easier, such as resistances, capacitances, inertia moments and friction coefficients. Two versions for the controller algorithm with the stability analysis are presented. The global asymptotic stability with respect to a compact set is guaranteed for both cases. Simulation results under adverse operation conditions in order to verify the theoretical results and to show the performance and robustness of the proposed controller are showed. Moreover, for practical purposes, some simplifications on the original algorithm are developed
Resumo:
In this work, the variable structure adaptive pole placement controller (VS-APPC) robustness and performance are evaluated and this algorithm is applied in a motor control system. The controller robustness evaluation will be done through simulations, where will be introduced in the system the following adversities: time delay, actuator response boundeds, disturbances, parametric variation and unmodeled dynamics. The VS-APPC will be compared with PI control, pole placement control (PPC) and adaptive pole placement controller (APPC). The VS-APPC will be simulated to track a step and a sine reference. It will be applied in a three-phase induction motor control system to track a sine signal in the stator reference frame. Simulation and experimental results will prove the efficiency and robustness of this control strategy
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This work develops a robustness analysis with respect to the modeling errors, being applied to the strategies of indirect control using Artificial Neural Networks - ANN s, belong to the multilayer feedforward perceptron class with on-line training based on gradient method (backpropagation). The presented schemes are called Indirect Hybrid Control and Indirect Neural Control. They are presented two Robustness Theorems, being one for each proposed indirect control scheme, which allow the computation of the maximum steady-state control error that will occur due to the modeling error what is caused by the neural identifier, either for the closed loop configuration having a conventional controller - Indirect Hybrid Control, or for the closed loop configuration having a neural controller - Indirect Neural Control. Considering that the robustness analysis is restrict only to the steady-state plant behavior, this work also includes a stability analysis transcription that is suitable for multilayer perceptron class of ANN s trained with backpropagation algorithm, to assure the convergence and stability of the used neural systems. By other side, the boundness of the initial transient behavior is assured by the assumption that the plant is BIBO (Bounded Input, Bounded Output) stable. The Robustness Theorems were tested on the proposed indirect control strategies, while applied to regulation control of simulated examples using nonlinear plants, and its results are presented
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This work shows a study about the Generalized Predictive Controllers with Restrictions and their implementation in physical plants. Three types of restrictions will be discussed: restrictions in the variation rate of the signal control, restrictions in the amplitude of the signal control and restrictions in the amplitude of the Out signal (plant response). At the predictive control, the control law is obtained by the minimization of an objective function. To consider the restrictions, this minimization of the objective function is done by the use of a method to solve optimizing problems with restrictions. The chosen method was the Rosen Algorithm (based on the Gradient-projection). The physical plants in this study are two didactical systems of water level control. The first order one (a simple tank) and another of second order, which is formed by two tanks connected in cascade. The codes are implemented in C++ language and the communication with the system to be done through using a data acquisition panel offered by the system producer
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This work presents an analysis of the control law based on an indirect hybrid scheme using neural network, initially proposed for O. Adetona, S. Sathanathan and L. H. Keel. Implementations of this control law, for a level plant of second order, was resulted an oscillatory behavior, even if the neural identifier has converged. Such results had motivated the investigation of the applicability of that law. Starting from that, had been made stability mathematical analysis and several implementations, with simulated plants and with real plants, for analyze the problem. The analysis has been showed the law was designed being despised some components of dynamic of the plant to be controlled. Thus, for plants that these components have a significant influence in its dynamic, the law tends to fail
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This paper describes the study, computer simulation and feasibility of implementation of vector control speed of an induction motor using for this purpose the Extended Kalman Filter as an estimator of rotor flux. The motivation for such work is the use of a control system that requires no sensors on the machine shaft, thus providing a considerable cost reduction of drives and their maintenance, increased reliability, robustness and noise immunity as compared to control systems with conventional sensors
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The control of industrial processes has become increasingly complex due to variety of factory devices, quality requirement and market competition. Such complexity requires a large amount of data to be treated by the three levels of process control: field devices, control systems and management softwares. To use data effectively in each one of these levels is extremely important to industry. Many of today s industrial computer systems consist of distributed software systems written in a wide variety of programming languages and developed for specific platforms, so, even more companies apply a significant investment to maintain or even re-write their systems for different platforms. Furthermore, it is rare that a software system works in complete isolation. In industrial automation is common that, software had to interact with other systems on different machines and even written in different languages. Thus, interoperability is not just a long-term challenge, but also a current context requirement of industrial software production. This work aims to propose a middleware solution for communication over web service and presents an user case applying the solution developed to an integrated system for industrial data capture , allowing such data to be available simplified and platformindependent across the network