Mestrado em Sistemas de Comunicação e Automação

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    Aplicação de algoritmos genéticos ao problema de planejamento de caminhos com a abordagem de decomposição em células convexas para o caso aproximado
    (Universidade Federal Rural do Semi-Árido, 2012-10-26) Pereira, Jonathan Paulo Pinheiro; Queiroz Junior, Idalmir de Souza; http://lattes.cnpq.br/8047604543096116; Silva, José Patrocínio da; http://lattes.cnpq.br/5753289728835624; Queiroz Júnior, Idalmir de Souza; http://lattes.cnpq.br/8047604543096116; Garcia, Antônio Ronaldo Gomes; http://lattes.cnpq.br/1291080711578781; Soares, Heliana Bezerra; http://lattes.cnpq.br/5057165446370629
    This work presents an application of Genetic Algorithms (GA) to solve the path planning problem using the approximate convex cell decomposition method. The algorithm is used to determine the shortest path between the origin and destination points in the connectivity graph generated by the cell decomposition method. The main objective of this study is the evaluation of the performance in the use of the GA of heuristic or adaptive criterion in relation to the use of the algorithm with greedy criterion, Djikstra. Computer simulations using the C language show tests to verify the influence of factors on the computational cost such as population size and the chromosome initialization method. The graphical observation of the configuration space and generation of the trajectory is obtained through an application in SCILAB. For experimental validation of the algorithm, a mobile robotic platform with differential drive was developed that receives the points of the trajectory through a radio link
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    Estudo e implementação de sistemas de controle para quadricóptero
    (Universidade Federal Rural do Semi-Árido, 2018-06-26) Alves, Íngrid Heloisa da Silva; Vale, Marcelo Roberto Bastos Guerra; 048922064090; http://lattes.cnpq.br/5510574256894005; Guerra, Fabiana Karla de Oliveira Martins Varella; http://lattes.cnpq.br/2711699996455302; Guerra, Fabiana Karla de Oliveira Martins Varella; 03513245424; http://lattes.cnpq.br/2711699996455302; Guerra, Fabiana Karla de Oliveira Martins Varella; 03513245424; http://lattes.cnpq.br/2711699996455302; Vale, Marcelo Roberto Bastos Guerra; 048922064090; http://lattes.cnpq.br/5510574256894005; Casillo, Danielle Simone da Silva; 02796900452; http://lattes.cnpq.br/2111858571672626; Araújo Júnior, José de Medeiros de; 03882174480; http://lattes.cnpq.br/3758667796324850
    The oil and gas industry deals with the transportation and storage of flammable substances at high pressure, requiring continuous monitoring of its structures to avoid damage to the environment, population, economic losses and production stoppages. In view of the current complexity of exploration environments and the continuing necessity of society for products from this sector, the petrochemical industry has been searching for ways to apply automation in order to reduce costs and ensure better security for the environment and the people involved. In this sense, the use of the quadcopter for the inspection and monitoring is an alternative that has been implemented in the last years, consisting of an Unmanned Aerial Vehicle (UAV). Therefore, it is necessary that the quadcopter performs the flight in diverse environments, being a robust and fast response controller in order to avoid the loss of stability and fall. This fact implies the necessity to develop a quadcopter control system that performs control of engine speed and flight altitude. For this reason, we developed and simulated altitude controls, using PID (Proportional Integral Derivative) and Fuzzy Logic control techniques, as well as for speed control of the motors, using a PID controller. To perform the simulation, it was necessary to survey the dynamic modeling of the quadcopter and engines, in order to obtain the approximate mathematical representation of the actual behavior of the vehicle to be controlled. The simulation of systems with controllers was performed using Simulink/MATLAB® software, in which we observed performance parameters such as rise time, overshoot, among others, and compared the responses. Finally, we performed tests on an prototype using the Arduino® platform, in order to verify the behavior of the system. For the altitude control, the simulations showed that with the PID controller we obtain a faster response of the system, but with the Fuzzy controller we obtain a lower overshoot and error. However, this result can not be generalized since the Fuzzy controller depends on the knowledge of a specialist and better answers can be obtained. Regarding the speed control of the motors, the use of the PID controller obtained a faster simulated response and less error when compared to the the system using only the Electronic Speed Controller (ESC). The experimental tests verified the actual behavior of the system with the PID controllers, presenting quantitative deviations to the simulated results due to the presence of disturbances during the flight and the simplifications made in the modeling of the system
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    Desenvolvimento de metodologias para localização de faltas em linhas de transmissão a partir de medidas não sincronizadas de dois terminais
    (Universidade Federal Rural do Semi-Árido, 2018-08-28) Oliveira Neto, Moisés Honorato de; Cruz, Melinda Cesianara Silva da; 05590713455; http://lattes.cnpq.br/8555051036360867; Moura, Adriano Aron Freitas de; 02428723373; http://lattes.cnpq.br/7699437598190399; Medeiros Júnior, Manoel Firmino de; 09615687472; http://lattes.cnpq.br/4960078797028638
    The Brazilian electric system formed by numerous transmission lines, that connect the centers of consumption to the centers of generation. When a permanent fault occurs on one of these lines, the work of the maintenance teams to locate the point of failure is usually time- consuming, which entails several financial losses, both for the consuming companies and for the concessionaire. The oil sector, for example, is one of the major impaired due to the shutdown of transmission lines that serve the extraction fields. In this sense, studies related to the location of faults in transmission lines have been very frequent in the literature. These studies have the general objective of determining precisely the location of the fault, assisting the maintenance teams in the rapid restoration of the energy supply. This work was intended to develop two methodologies for locating faults in transmission lines, both based on unsynchronized fundamental Fasos of two terminals. The methodologies presented two steps. In the first stage, called the processing stage, the voltage and current, synchronized, of the two terminals of the transmission line were obtained. In the second step, localization methodologies were implemented, developed from the concept of minimum squares. For the validation of the methods, there were simulated, in the ATP software, faults in different transmission lines. The performances of the localization algorithms were therefore evaluated considering short circuits in several locations of the line, and for different resistances of lack. The results obtained showed that the developed methodologies are accurate and represent important tools to compose the state of the art of locating faults in transmission lines
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    Iot baseada em phm aplicada a centrais condicionadoras de ar
    (Universidade Federal Rural do Semi-Árido, 2018-12-20) Bezerra, Bemielison Gletson da Silva; Guerra, Fabianna Karla de Oliveira Martins Varella; 03513245424; http://lattes.cnpq.br/2711699996455302; Vale, Marcelo Roberto Bastos Guerra; 04892206490; http://lattes.cnpq.br/5510574256894005; Araújo Júnior, José Medeiros de; 03882174480; http://lattes.cnpq.br/3758667796324850; Moura, Adriano Aron Freitas de; 02458723373; http://lattes.cnpq.br/7699437598190399
    In recent years, air conditioning has become more accessible to the population, either by improving the quality of life or reducing the inputs used in the construction of equipment. Driven by the technological advancements of individual components or manufacturing processes and energy matrices, concern with factors such as maintenance and reduction of energy consumption has become even greater. In general, the most commonly used maintenance option is the corrective (break-repair), which is the most costly aggregate, since until the complete failure of the equipment many components of the system may be damaged. Therefore, the costs are increased, the increase of the electric energy consumption during the period of malfunction of the equipment until the forced stop of the same. In this sense, the innovation and reduction of the components sensors and actuators, as well as of the communication technologies has enabled the monitoring of the working conditions and health prognoses of the most diverse equipment, being denominated of "Internet of Things", or IoT, the insertion of sensors and internet connection of any object that surrounds us In this work, IoT-based hardware and firmware were developed with the application of predictive maintenance techniques CBM (Condition-Based Maintenance) and PHM (Prognostics and system health management) for acquisition and data measurement of an air conditioning central, such as: active, reactive, apparent power consumption and power factor. The hardware contains three electronic boards (power, measurement and control) designed in CadSoft's Eagle software and manufactured in fiberglass printed circuit board. The firmware was implemented in the Integrated Development Environment (IDE) of the Arduino electronic prototyping platform, in communication with the remote server (Rasberry Pi computer) through an MQTT (MQTT communications server) broker. The system was calibrated; and subsequently the data acquisition and measurement tests were performed. The results obtained from the monitoring of variables and control of the air conditioner in the manual and automatic mode were quite satisfactory for this application, proving to be a useful tool in the management of maintenance and reduction of waste with electric energy
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    Desenvolvimento de antena de microfita baseada no fractal de cantor com plano de terra truncado
    (Universidade Federal Rural do Semi-Árido, 2018-02-02) Brito, Bruno Marcel de Carvalho; Andrade, Humberto Dionísio de; 91620040425; http://lattes.cnpq.br/1253785596446469; Queiroz Júnior, Idalmir de Souza; 63510731468; http://lattes.cnpq.br/8047604543096116; Fernandes Neto, André Pedro; 67306721453; http://lattes.cnpq.br/6481909544754185; Sousa Neto, Marinaldo Pinheiro de; 72058870468; http://lattes.cnpq.br/2524160890713257
    The development of antenna research has intensified in recent years, especially related to microstrip antennas. Features such as small volume, reduced weight, low cost and ease of manufacturing are observed in microstrip antenna designs, which explains the popularization of this line of research. However, with the constant evolution of technology in communication systems, the equipment requires an antenna with increasingly smaller size and great capacity of data transfer. In this context, the application of Fractal Geometry, based on the Cantor Sequence, on microstrip antenna structures has become a very effective alternative in research projects of the sector. The main feature that a fractal structure presents is an effective miniaturization in its physical dimensions without significantly reducing the bandwidth and efficiency of the antenna. With the need for antennas with greater data transfer capacity, a very desirable feature in antennas is a bandwidth with considerable size. For this, the technique of reduction of the ground plane has been notable for being able to extend the range of operation in antennas where the reduction is applied. Aiming to carry out a study on the modifications of the electric characteristics in an antenna with application of the fractal geometry and reduction of the ground plane, a parametric study was execute to find the best configurations of the projected antennas. Successive simulations was execute with the aid of HFSS® (High Frequency Structural Simulator), to obtain 2D and 3D radiation pattern, return loss, bandwidth and gain. With this simulated information, the antennas were chosen, which presented the most desirable characteristics for manufacturing and consequent comparison between the simulated values and the values obtained with the measurement of the antennas manufactured
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    Projeto de antena de microfita com polarização circular para aplicação em veículos aéreos não tripulados
    (Universidade Federal Rural do Semi-Árido, 2018-02-28) Araújo, Alexandre de Moraes; Fontgalland, Glauco; 50405578415; http://lattes.cnpq.br/4256595317953538; Fernandes Neto, André Pedro; 67306721453; http://lattes.cnpq.br/6481909544754185; Fernandes Neto, André Pedro; 67306721453; http://lattes.cnpq.br/6481909544754185; Andrade, Humberto Dionísio de; 91620040435; http://lattes.cnpq.br/1253785596446469; Queiroz Junior, Idalmir de Souza; 63510731468; http://lattes.cnpq.br/8047604543096116; Sousa Neto, Marinaldo Pinheiro de; 06496972435; http://lattes.cnpq.br/2524160890713257
    Demand in wireless networks has increased considerably in recent years. Consequently, the study of system components has also increased. Within this context, antennas are fundamental elements in the physical layer in radiofrequency communications, and their study has become a research area with great advances. The need in certain systems for smaller antennas and more adaptability in the space makes the microstrip antennas in potential substitutes of the traditional antennas. This work aims to find prototypes of microfite antennas that have physical and electrical characteristics, such as gain and polarization, superior to the commercial antennas of a FPV communication system (First Person View) operating at 5.8 GHz. The methodology used in this research consists of a theoretical survey about circular polarization antennas, design, simulate and construct these antennas using different substrates in order to verify their performance and to ship them in an FPV system. The results obtained through the simulation are compared with the experimental results in order to attest to the model in question based on the literature used in this work. Preliminarily, the simulated and measured results show that the Triangular Patch Antennas have all the desirable characteristics for operation in the FPV system, being possible to board them for the obtaining of images and analysis of the performance of the system