Controle de atitude e altitude para um veículo aéreo não tripulado do tipo quadrirrotor

A Quadrotor is an Unmanned Aerial Vehicle (UAV) equipped with four rotors distributed on a simple mechanical "X"form structure. The aim of this work is to build and stabilize a Quadrotor aircraft in the roll, pitch and yaw angles at a certain altitude. The stabilization control approach is based on a transformation in the input variables in order to perform a decoupled control. The proposed strategy is based on breaking the control problem into two hierarchical levels: A lower level, object of this work, maintains the desired altitude an angles of the vehicle while the higher level establishes appropriate references to the lower level, performing the desired movements. A hardware and software architecture was specially developed and implemented for an experimental prototype used to test and validate the proposed control approach

Novas ferramentas para monitoramento ambiental usando SIG Web

The use of Geographic Information Systems (GIS) has becoming very important in fields where detailed and precise study of earth surface features is required. Applications in environmental protection are such an example that requires the use of GIS tools for analysis and decision by managers and enrolled community of protected areas. In this specific field, a challenge that remains is to build a GIS that can be dynamically fed with data, allowing researchers and other agents to recover actual and up to date information. In some cases, data is acquired in several ways and come from different sources. To solve this problem, some tools were implemented that includes a model for spatial data treatment on the Web. The research issues involved start with the feeding and processing of environmental control data collected in-loco as biotic and geological variables and finishes with the presentation of all information on theWeb. For this dynamic processing, it was developed some tools that make MapServer more flexible and dynamic, allowing data uploading by the proper users. Furthermore, it was also developed a module that uses interpolation to aiming spatial data analysis. A complex application that has validated this research is to feed the system with data coming from coral reef regions located in northeast of Brazil. The system was implemented using the best interactivity concept provided by the AJAX model and resulted in a substantial contribution for efficiently accessing information, being an essential mechanism for controlling events in the environmental monitoring

Desenvolvimento e implementação de um sistema de supervisão e controle residencial

With the technological progress the people are more and more looking for convenience, comfort and safety to your homes. The residential automation is winning space on the market not only by the status and modernity that provide, but also to allow a better use of natural resources, reducing the expense to keep up a residence. This work shows the development of a control system and supervision to be destined to the residential automation. The developed software will be working together with a controller (PLC), acting in the administration, control and supervision all the linked devices, and offering to the user an environment simple and practical for the control residence

Estrutura ANFIS modificada para identificação e controle de plantas com ampla faixa de operação e não linearidade acentuada

In this work a modification on ANFIS (Adaptive Network Based Fuzzy Inference System) structure is proposed to find a systematic method for nonlinear plants, with large operational range, identification and control, using linear local systems: models and controllers. This method is based on multiple model approach. This way, linear local models are obtained and then those models are combined by the proposed neurofuzzy structure. A metric that allows a satisfactory combination of those models is obtained after the structure training. It results on plant s global identification. A controller is projected for each local model. The global control is obtained by mixing local controllers signals. This is done by the modified ANFIS. The modification on ANFIS architecture allows the two neurofuzzy structures knowledge sharing. So the same metric obtained to combine models can be used to combine controllers. Two cases study are used to validate the new ANFIS structure. The knowledge sharing is evaluated in the second case study. It shows that just one modified ANFIS structure is necessary to combine linear models to identify, a nonlinear plant, and combine linear controllers to control this plant. The proposed method allows the usage of any identification and control techniques for local models and local controllers obtaining. It also reduces the complexity of ANFIS usage for identification and control. This work has prioritized simpler techniques for the identification and control systems to simplify the use of the method

Motor de indução trifásico sem mancais com bobinado dividido: otimização do sistema de posicionamento radial

This dissertation dea1s with the active magnetic suspension controI system of an induction bearingIess motor configured with split windings. It analyses a dynamic modeI for the radial magnetic forces actuating on the rotor. From that, it proposes a new approach for the composition of the currents imposed to the machine's stator. It shows the tests accomplished with a prototype, proving the usefulness of the new actuating structure for the radial positioning controI. Finnaly, it points out the importance of adapting this structure to well-known rotational controI techniques, continuing this kind of equipment research, which is carried out at Federal University of Rio Grande do Norte since 2000

Controle preditivo bilinear aplicado a um motor de indução

The present work is based on the applied bilinear predictive control applied to an induction motor. As in particular case of the technique based on predictive control in nonlinem systems, these have desperted great interest, a time that present the advantage of being simpler than the non linear in general and most representative one than the linear one. One of the methods, adopted here, uses the linear model "quasi linear for step of time" based in Generalized Predictive Control. The modeling of the induction motor is made by the Vectorial control with orientation given for the indirect rotor. The system is formed by an induction motor of 3 cv with rotor in squirregate, set in motion for a group of benches of tests developed for this work, presented resulted for a variation of +5% in the value of set-point and for a variation of +10% and -10% in the value of the applied nominal load to the motor. The results prove a good efficiency of the predictive bilinear controllers, then compared with the linear cases

Qualidade pós-colheita de mangas, não-refrigeradas, e submetidas ao controle da ação do etileno

O presente trabalho objetivou-se na caracterização físico-química de mangas cv. Tommy Atkins e Haden, submetidas ao controle da ação do etileno, através da exposição dos frutos à ação de adsorvedores de etileno. Os frutos colhidos em estádio de fisiologicamente maturos foram embalados em filmes de polietileno de baixa densidade (PEBD) de 0,006 mm de espessura, com ou sem o sachê de adsorção de etileno, e acondicionados em embalagens de papelão (0,65 x 0,52 m), sem o controle da temperatura e da umidade relativa (30 ± 3 ºC e 70 ± 5 % de U.R.). Os tratamentos ficaram constituídos dessa maneira: T1 - mangas cv. Tommy Atkins, com o sachê de adsorção; T2 - mangas cv. Tommy Atkins, sem o sachê de adsorção; T3- mangas cv. Haden com o sachê de adsorção, e T4 - mangas cv Haden sem o sachê de adsorção. As análises de firmeza de polpa, sólidos solúveis (SS), acidez titulável (AT), pH, ácido ascórbico e concentração de etileno foram realizadas na instalação do experimento (dia 0), e aos 7; 14; 21; 28 e 35 dias; e aos 35 dias foi realizado um teste de preferência. Ao final do experimento, observou-se que, em ambas as cultivares, a menor concentração de etileno nas embalagens, a maior firmeza de polpa, a maior contenção no avanço e na diminuição do SS e AT, respectivamente, bem como a melhor manutenção do conteúdo de ácido ascórbico foram detectadas nos frutos acondicionados em embalagens contendo o sachê de adsorção de etileno. Não foram detectadas variações significativas nos valores de pH. No teste de preferência, houve variação significativa, onde os frutos acondicionados sob ação do adsorvedor de etileno foram preferidos por parte dos julgadores.

Uma fonte chaveada de 50kW com correção de fator de potência para alimentação de uma tocha de plasma Indutiva utilizando técnicas de controle digital

This work deals with the development of an experimental study on a power supply of high frequency that provides the toch plasmica to be implemented in PLASPETRO project, which consists of two static converters developed by using Insulated Gate Bipolar Transistor (IGBT). The drivers used to control these keys are triggered by Digital Signal Processor (DSP) through optical fibers to reduce problems with electromagnetic interference (EMI). The first stage consists of a pre-regulator in the form of an AC to DC converter with three-phase boost power factor correction which is the main theme of this work, while the second is the source of high frequency itself. A series-resonant inverter consists of four (4) cell inverters operating in a frequency around 115 kHz each one in soft switching mode, alternating itself to supply the load (plasma torch) an alternating current with a frequency of 450 kHz. The first stage has the function of providing the series-resonant inverter a DC voltage, with the value controlled from the power supply provided by the electrical system of the utility, and correct the power factor of the system as a whole. This level of DC bus voltage at the output of the first stage will be used to control the power transferred by the inverter to the load, and it may vary from 550 VDC to a maximum of 800 VDC. To control the voltage level of DC bus driver used a proportional integral (PI) controller and to achieve the unity power factor it was used two other proportional integral currents controllers. Computational simulations were performed to assist in sizing and forecasting performance. All the control and communications needed to stage supervisory were implemented on a DSP

Técnica de controle adaptativo robusto aplicada a filtros ativos de potência e paralelo

The Methods for compensation of harmonic currents and voltages have been widely used since these methods allow to reduce to acceptable levels the harmonic distortion in the voltages or currents in a power system, and also compensate reactive. The reduction of harmonics and reactive contributes to the reduction of losses in transmission lines and electrical machinery, increasing the power factor, reduce the occurrence of overvoltage and overcurrent. The active power filter is the most efficient method for compensation of harmonic currents and voltages. The active power filter is necessary to use current and voltage controllers loop. Conventionally, the current and voltage control loop of active filter has been done by proportional controllers integrative. This work, investigated the use of a robust adaptive control technique on the shunt active power filter current and voltage control loop to increase robustness and improve the performance of active filter to compensate for harmonics. The proposed control scheme is based on a combination of techniques for adaptive control pole placement and variable structure. The advantages of the proposed method over conventional ones are: lower total harmonic distortion, more flexibility, adaptability and robustness to the system. Moreover, the proposed control scheme improves the performance and improves the transient of active filter. The validation of the proposed technique was verified initially by a simulation program implemented in C++ language and then experimental results were obtained using a prototype three-phase active filter of 1 kVA

Controlador preditivo generalizado multi-modelo aplicado ao controle de pressão arterial

Postsurgical complication of hypertension may occur in cardiac patients. To decrease the chances of complication it is necessary to reduce elevated blood pressure as soon as possible. Continuous infusion of vasodilator drugs, such as sodium nitroprusside (Nipride), would quickly lower the blood pressure in most patients. However, each patient has a different sensitivity to infusion of Nipride. The parameters and the time delays of the system are initially unknown. Moreover, the parameters of the transfer function associated with a particular patient are time varying. the objective of the study is to develop a procedure for blood pressure control i the presence of uncertainty of parameters and considerable time delays. So, a methodology was developed multi-model, and for each such model a Preditive Controller can be a priori designed. An adaptive mechanism is then needed for deciding which controller should be dominant for a given plant

Identificação de uma planta de corrente de um motor de indução utilizando redes de base radial

The present work describes the use of a mathematical tool to solve problems arising from control theory, including the identification, analysis of the phase portrait and stability, as well as the temporal evolution of the plant s current induction motor. The system identification is an area of mathematical modeling that has as its objective the study of techniques which can determine a dynamic model in representing a real system. The tool used in the identification and analysis of nonlinear dynamical system is the Radial Basis Function (RBF). The process or plant that is used has a mathematical model unknown, but belongs to a particular class that contains an internal dynamics that can be modeled.Will be presented as contributions to the analysis of asymptotic stability of the RBF. The identification using radial basis function is demonstrated through computer simulations from a real data set obtained from the plant

Estratégia de controle robusto para filtro ativo paralelo sem detecção de harmônicos de correntes

Conventional control strategies used in shunt active power filters (SAPF) employs real-time instantaneous harmonic detection schemes which is usually implements with digital filters. This increase the number of current sensors on the filter structure which results in high costs. Furthermore, these detection schemes introduce time delays which can deteriorate the harmonic compensation performance. Differently from the conventional control schemes, this paper proposes a non-standard control strategy which indirectly regulates the phase currents of the power mains. The reference currents of system are generated by the dc-link voltage controller and is based on the active power balance of SAPF system. The reference currents are aligned to the phase angle of the power mains voltage vector which is obtained by using a dq phase locked loop (PLL) system. The current control strategy is implemented by an adaptive pole placement control strategy integrated to a variable structure control scheme (VS¡APPC). In the VS¡APPC, the internal model principle (IMP) of reference currents is used for achieving the zero steady state tracking error of the power system currents. This forces the phase current of the system mains to be sinusoidal with low harmonics content. Moreover, the current controllers are implemented on the stationary reference frame to avoid transformations to the mains voltage vector reference coordinates. This proposed current control strategy enhance the performance of SAPF with fast transient response and robustness to parametric uncertainties. Experimental results are showing for determining the effectiveness of SAPF proposed control system

Controle preditivo robusto baseado em desigualdades matriciais lineares aplicado a um sistema de tanques acoplados

This work deals with an on-line control strategy based on Robust Model Predictive Control (RMPC) technique applied in a real coupled tanks system. This process consists of two coupled tanks and a pump to feed the liquid to the system. The control objective (regulator problem) is to keep the tanks levels in the considered operation point even in the presence of disturbance. The RMPC is a technique that allows explicit incorporation of the plant uncertainty in the problem formulation. The goal is to design, at each time step, a state-feedback control law that minimizes a 'worst-case' infinite horizon objective function, subject to constraint in the control. The existence of a feedback control law satisfying the input constraints is reduced to a convex optimization over linear matrix inequalities (LMIs) problem. It is shown in this work that for the plant uncertainty described by the polytope, the feasible receding horizon state feedback control design is robustly stabilizing. The software implementation of the RMPC is made using Scilab, and its communication with Coupled Tanks Systems is done through the OLE for Process Control (OPC) industrial protocol

Avaliação operacional do controle mecânico de plantas aquáticas imersas no reservatório de Jupiá

O presente trabalho foi realizado com o objetivo de estudar a coleta e o descarte de plantas aquáticas em diferentes locais e infestações do sistema Tietê/Paraná, no reservatório de Jupiá. A operação foi realizada com auxílio de instrumentação instalada em uma colhedora de plantas aquáticas, com sistema de GPS dotado de sinal de correção diferencial. Os tempos gastos para carregar e descarregar a colhedora foram determinados por cronometragem, e a distância do ponto final de coleta ao ponto de descarte e o tempo de deslocamento, por cronometragem e uso de GPS convencional. em algumas coletas foram demarcados polígonos, instruindo-se o operador a trabalhar exclusivamente na área correspondente. A interpretação dos resultados permitiu determinar a participação do tempo de coleta em relação ao tempo total de operação, indicando um valor significativo do ponto de vista operacional (>70%). Considerando o descarte em áreas infestadas com taboa, o deslocamento total médio foi de apenas 383 m, com gasto médio de 200,96 s. Os valores de capacidade operacional da colhedora oscilaram entre 0,23 e 1,60 ha h-1, indicando valor médio de 4,48 ha dia-1. A maior limitação à capacidade operacional associou-se à velocidade média de deslocamento, com maior agravante em áreas com altas infestações ou profundas. Considerando-se o deslocamento da colhedora, houve grande dificuldade de orientação em condições normais de operação, inviabilizando a manutenção de espaçamentos uniformes entre as faixas de coleta e sobrepondo as passagens. Conclui-se que a avaliação operacional indicou a impossibilidade de operar a colhedora sem o auxílio de um sistema de navegação que permita orientar a sua movimentação nas áreas de controle.

Otimização do controle eletrônico do diagrama de radiação de arranjos de antenas usando algoritmos genéticos com codificação real

Antenna arrays are able to provide high and controlled directivity, which are suitable for radiobase stations, radar systems, and point-to-point or satellite links. The optimization of an array design is usually a hard task because of the non-linear characteristic of multiobjective, requiring the application of numerical techniques, such as genetic algorithms. Therefore, in order to optimize the electronic control of the antenna array radiation pattem through genetic algorithms in real codification, it was developed a numerical tool which is able to positioning the array major lobe, reducing the side lobe levels, canceling interference signals in specific directions of arrival, and improving the antenna radiation performance. This was accomplished by using antenna theory concepts and optimization methods, mainly genetic algorithms ones, allowing to develop a numerical tool with creative genes codification and crossover rules, which is one of the most important contribution of this work. The efficiency of the developed genetic algorithm tool is tested and validated in several antenna and propagation applications. 11 was observed that the numerical results attend the specific requirements, showing the developed tool ability and capacity to handle the considered problems, as well as a great perspective for application in future works.