134 resultados para control system
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The fierce competitiveness of the current market and the sophistication of customer requirements made the commitment to quality a need within organizations. The search for quality has been carried out by the adoption of quality management systems, a formal organization that should be present throughout the organization, from the initial identification of market needs to the satisfaction of customer requirements. The methodology most commonly used for this purpose is based on the requirements of ISO 9001, latest version of 2008. Considering this scenario, was developed a case study in a small company of the industrial sector with the development of a plan for the implementation of ISO 9001. The proposed methodology involved the construction of a theoretical framework on the subject and the development of a case study with a qualitative approach. Initially, was applied a questionnaire to the representative of the organization about the company's operating procedures, activity logs held, current documentation, planning and resource management for the construction of an assessment about the adequacy of the company needs to ISO 9001. Were obtained as results the characterization of production processes and organizational structure of the company and examples of policy and objectives of quality, performance indicators, document control, system for visualization of non-compliances, among others. Finally, the benefits of adopting a quality management system based on ISO 9001 requirements for the company and its environmental issues such as increased process efficiency, less waste and greater profitability, were pointed out, and the conditions for effective certification in the future
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Pós-graduação em Engenharia Elétrica - FEB
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Pós-graduação em Engenharia Elétrica - FEIS
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Pós-graduação em Engenharia Elétrica - FEIS
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This paper presents the development and the main results for an interleaved boost rectifier operating as a special input power stage for a trolleybus type vehicle, allowing its feeding by alternate current (AC) or direct current (DC) distribution power systems. When feeding with two wires (single phase) alternate current distribution system, the converter accomplish active power factor correction, providing a relatively sinusoidal current with low total harmonic distortion (THD) and fully complying with IEC 61000-3-4 standards. In addition, a management control system promotes the required automatic operation changes for the proposed rectifier when the vehicle is changing from the DC distribution power system to the AC distribution power system and vice-versa, keeping its original electrical DC system characteristics for the adjustable speed driver sub-system. The main experimental results for a prototype rated at 150kW are presented, considering its application for a trolleybus with DC adjustable speed driver, demonstrating the proposed converter benefits and the possibility of AC feeding system for trolleybus type vehicle.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The present work investigates the nonlinear response of a half-car model. The disturbances of the road are assumed to be sinusoidal. After constructing the bifurcation diagram, we use the 0-1 test to identify chaotic motions. The main objective of this study is to eliminate chaotic behavior of the chassis and reduce its vibrations. To accomplish this, a semi-active vehicle suspension control system, using magneto-rheological dampers, is proposed. The proposed semi-active control strategy consists of two nonlinear control laws: a feedforward control, and a feedback control. They are obtained by considering the SDRE (State Dependent Riccati Equation) control, where the control parameter is the voltage applied to the coils of the magneto-rheological dampers. Numerical results show that the proposed control method is effective in significantly reducing of the chassis vibration, increasing, therefore, passenger comfort.
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During the last 30 years the Atomic Force Microscopy became the most powerful tool for surface probing in atomic scale. The Tapping-Mode Atomic Force Microscope is used to generate high quality accurate images of the samples surface. However, in this mode of operation the microcantilever frequently presents chaotic motion due to the nonlinear characteristics of the tip-sample forces interactions, degrading the image quality. This kind of irregular motion must be avoided by the control system. In this work, the tip-sample interaction is modelled considering the Lennard-Jones potentials and the two-term Galerkin aproximation. Additionally, the State Dependent Ricatti Equation and Time-Delayed Feedback Control techniques are used in order to force the Tapping-Mode Atomic Force Microscope system motion to a periodic orbit, preventing the microcantilever chaotic motion
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Relações Internacionais (UNESP - UNICAMP - PUC-SP) - FFC
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The use of alternative energy systems in the current days is an urgent necessity due to the problems that the planet is facing as the heating and loss of ozone layer. The scarcity of conventional energy is another problem that must be solved for the future of humanity. It must be considered that the people are inhabiting places moved away not always with available energy. The application of technologies as automation and control can help us to solve this problem. Therefore, this work aimed at apply an equipment of industrial usage, the Programmable Logical Controller, PLC, in alternative energies systems, as eolic generation and fotovoltaic generation used for water pumping, aiming the automatic control and the efficiency in the places where it has simultaneous availability of these sources, based in criterion of priority that previously established itself between them. It was made a hydraulic and energetic evaluation of the energy system, eolic and fotovoltaic, used in the automatic control system of pumping, in the place of accomplishment of the experiment, according to previously established physical conditions. The results have shown that the control system using the PLC is practicable and has trustworthiness. The program developed can be adapted for the use with several power plants in a specific application place. The fotovoltaic system of pumping, using a polycrystalline of 70 Watts connected to a pump Shurflo 8000, showed to be efficient with significant flows in almost all the months. The eolic system of pumping, using an eolic generator of 400 Watts assembled in place of experiment, did not demonstrate energetic capacity for use in this specific type of application.
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This paper presents the application and use of a methodology based on fuzzy theory and simulates its use in intelligent control of a hybrid system for generating electricity, using solar energy, photovoltaic and wind. When using a fuzzy control system, it reached the point of maximum generation of energy, thus shifting all energy generated from the alternative sources-solar photovoltaic and wind, cargo and / or batteries when its use not immediately. The model uses three variables used for entry, which are: wind speed, solar radiation and loading the bank of batteries. For output variable has to choose which of the batteries of the battery bank is charged. For the simulations of this work is used MATLAB software. In this environment mathematical computational are analyzed and simulated all mathematical modeling, rules and other variables in the system described fuzzy. This model can be used in a system of control of hybrid systems for generating energy, providing the best use of energy sources, sun and wind, so we can extract the maximum energy possible these alternative sources without any prejudice to the environment.
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Pós-graduação em Ciência da Computação - IBILCE