Sistema automatizado para o aproveitamento de água cinza e azul, com controle de PH utilizando lógica fuzzy

Every day, water scarcity becomes a more serious problem and, directly affects global society. Studies are directed in order to raise awareness of the rational use of this natural asset that is essential to our survival. Only 0.007% of the water available in the world have easy access and can be consumed by humans, it can be found in rivers, lakes, etc... To better take advantage of the water used in homes and small businesses, reuse projects are often implemented, resulting in savings for customers of water utilities. The reuse projects involve several areas of engineering, like Environmental, Chemical, Electrical and Computer Engineering. The last two are responsible for the control of the process, which aims to make gray water (soapy water), and clear blue water (rain water), ideal for consumption, or for use in watering gardens, flushing, among others applications. Water has several features that should be taken into consideration when it comes to working its reuse. Some of the features are, turbidity, temperature, electrical conductivity and, pH. In this document there is a proposal to control the pH (potential Hydrogen) through a microcontroller, using the fuzzy logic as strategy of control. The controller was developed in the fuzzy toolbox of Matlab®

Controle fuzzy espacialmente diferenciado para um sistema de irrigação

Traditional irrigation projects do not locally determine the water availability in the soil. Then, irregular irrigation cycles may occur: some with insufficient amount that leads to water deficit, other with excessive watering that causes lack of oxygen in plants. Due to the nonlinear nature of this problem and the multivariable context of irrigation processes, fuzzy logic is suggested to replace commercial ON-OFF irrigation system with predefined timing. Other limitation of commercial solutions is that irrigation processes either consider the different watering needs throughout plant growth cycles or the climate changes. In order to fulfill location based agricultural needs, it is indicated to monitor environmental data using wireless sensors connected to an intelligent control system. This is more evident in applications as precision agriculture. This work presents the theoretical and experimental development of a fuzzy system to implement a spatially differentiated control of an irrigation system, based on soil moisture measurement with wireless sensor nodes. The control system architecture is modular: a fuzzy supervisor determines the soil moisture set point of each sensor node area (according to the soil-plant set) and another fuzzy system, embedded in the sensor node, does the local control and actuates in the irrigation system. The fuzzy control system was simulated with SIMULINK® programming tool and was experimentally built embedded in mobile device SunSPOTTM operating in ZigBee. Controller models were designed and evaluated in different combinations of input variables and inference rules base

Controle de Temperatura do Sistema de Refrigeração a água de uma tocha plasmática Indutiva Utilizando Lógica fuzzy

Este projeto propõe desenvolver e implementar um controlador para o sistema de refrigeração da tocha indutiva a plasma térmico. Este processo é feito a partir da medição da temperatura através de um sensor do sistema de refrigeração. O sinal produzido será enviado para uma entrada analógica do microcontrolador da família PIC, que utilizando os conceitos de lógica fuzzy, controla a velocidade de um motor bomba. Este é responsável por diminuir ou aumentar o fluxo circulante de água que passa pela bobina, pelo corpo da tocha e pelo flange de fixação, deixando-os na temperatura desejada. A velocidade desta bomba será controlada por um inversor de frequência. O microcontrolador, também, acionará um ventilador caso exceda a temperatura de referência. A proposta inicial foi o desenvolvimento do controle da temperatura da bobina de uma tocha indutiva a plasma, mas com algumas adequações, foi possível também aplicar no corpo da tocha. Essa tocha será utilizada em uma planta de tratamento de resíduos industriais e efluentes petroquímicos. O controle proposto visa garantir as condições físicas necessárias para tocha de plasma, mantendo a temperatura da água em um determinado nível que permita o resfriamento sem comprometer, no entanto, o rendimento do sistema. No projeto será utilizada uma tocha de plasma com acoplamento indutivo (ICPT), por ter a vantagem de não possuir eletrodos metálicos internos sendo erodidos pelo jato de plasma, evitando uma possível contaminação, e também devido à possibilidade do reaproveitamento energético através da cogeração de energia. O desenvolvimento da tecnologia a plasma na indústria de tratamento de resíduos vem obtendo bons resultados. Aplicações com essa tecnologia têm se tornado cada vez mais importantes por reduzir, em muitos casos, a produção de resíduos e o consumo de energia em vários processos industriais

Avaliação da usabilidade de um sistema informatizado de controle acadêmico: um estudo com coordenadores e secretários de cursos stricto sensu da UFRN

The aim of this study is to assess the usability of the Integrated Management System for Academic Activities (SIGAA) for the sensu stricto postgraduate programs at Universidade Federal do Rio Grande do Norte. The study was based on ergonomic criteria proposed by Bastien and Scapin (1993) and the Federal Government s Handbook of Usability (2010). The methodology used was a descriptive data survey involving an online questionnaire, and a sample of 46 system users, composed of coordinators and secretaries from the sensu stricto postgraduate programs. In addition to this procedure, open interviews were held with the users as well as a documental analysis of calls registered by them at the SIGAA between May 2012 and June 2013. Data analysis showed that a number of additional usability criteria need to be implemented, primarily related to ergonomic problems of orientation, error management and workload. Based on the analyses, several changes were proposed that may streamline secretarial activities, as well as provide greater satisfaction and interaction between the SIGAA and its users

Identificação e comparação entre controle preditivo com modelo não linear e PI sintonizados com PSO em sistema de separação gravitacional de águia-óleo

The separation methods are reduced applications as a result of the operational costs, the low output and the long time to separate the uids. But, these treatment methods are important because of the need for extraction of unwanted contaminants in the oil production. The water and the concentration of oil in water should be minimal (around 40 to 20 ppm) in order to take it to the sea. Because of the need of primary treatment, the objective of this project is to study and implement algorithms for identification of polynomial NARX (Nonlinear Auto-Regressive with Exogenous Input) models in closed loop, implement a structural identification, and compare strategies using PI control and updated on-line NARX predictive models on a combination of three-phase separator in series with three hydro cyclones batteries. The main goal of this project is to: obtain an optimized process of phase separation that will regulate the system, even in the presence of oil gushes; Show that it is possible to get optimized tunings for controllers analyzing the mesh as a whole, and evaluate and compare the strategies of PI and predictive control applied to the process. To accomplish these goals a simulator was used to represent the three phase separator and hydro cyclones. Algorithms were developed for system identification (NARX) using RLS(Recursive Least Square), along with methods for structure models detection. Predictive Control Algorithms were also implemented with NARX model updated on-line, and optimization algorithms using PSO (Particle Swarm Optimization). This project ends with a comparison of results obtained from the use of PI and predictive controllers (both with optimal state through the algorithm of cloud particles) in the simulated system. Thus, concluding that the performed optimizations make the system less sensitive to external perturbations and when optimized, the two controllers show similar results with the assessment of predictive control somewhat less sensitive to disturbances

Sistema de conversão de energia eólica baseado no gerador de indução duplamente alimentado: análise e contribuição ao controle da máquina

The humanity reached a time of unprecedented technological development. Science has achieved and continues to achieve technologies that allowed increasingly to understand the universe and the laws which govern it, and also try to coexist without destroying the planet we live on. One of the main challenges of the XXI century is to seek and increase new sources of clean energy, renewable and able to sustain our growth and lifestyle. It is the duty of every researcher engage and contribute in this race of energy. In this context, wind power presents itself as one of the great promises for the future of electricity generation . Despite being a bit older than other sources of renewable energy, wind power still presents a wide field for improvement. The development of new techniques for control of the generator along with the development of research laboratories specializing in wind generation are one of the key points to improve the performance, efficiency and reliability of the system. Appropriate control of back-to-back converter scheme allows wind turbines based on the doubly-fed induction generator to operate in the variable-speed mode, whose benefits include maximum power extraction, reactive power injection and mechanical stress reduction. The generator-side converter provides control of active and reactive power injected into the grid, whereas the grid-side converter provides control of the DC link voltage and bi-directional power flow. The conventional control structure uses PI controllers with feed-forward compensation of cross-coupling dq terms. This control technique is sensitive to model uncertainties and the compensation of dynamic dq terms results on a competing control strategy. Therefore, to overcome these problems, it is proposed in this thesis a robust internal model based state-feedback control structure in order to eliminate the cross-coupling terms and thereby improve the generator drive as well as its dynamic behavior during sudden changes in wind speed. It is compared the conventional control approach with the proposed control technique for DFIG wind turbine control under both steady and gust wind conditions. Moreover, it is also proposed in this thesis an wind turbine emulator, which was developed to recreate in laboratory a realistic condition and to submit the generator to several wind speed conditions.

Análise da atividade cognitiva do operador de sala de controle da produção de controle da produção de petróleo on-shore: uma abordagem da ergonomia para a gestão das restrições do sistema sociotécnico

This master's thesis aims to analyze the activity of the operators in a control room of the processes of production on-shore petroleum, with a focus on sociotechnical restrictions that interfere in the decision-making process and the actions of operators and therefore, the strategies (individual and collective) to regulate and maintain the operator action required and the safety of the system, together. The activity in focus involves the supervision and control of the production of thousands of barrels of oil/day in a complex and dispersed production’s structures built in an extension of 80 km. This operational framework highlights the importance of this activity for the fulfilment of the targets local and corporate efficiency, good management of the environment, health and safety of operators. This is an exploratory research and in the field, which uses the methodology of Ergonomic Analysis of the Work, composed of observational techniques and interactional, having as locus control room of the processes of production on-shore oil of an oil company. The population of this research is formed by operators in the control room of an Brazilian oil company. The results showed that the supervisory activity and control of the superheated steam injection is an complex context, demands greater attention, concentration, calculations, comparisons, trend analysis and decision making. The activity is collectively constructed between the control room operator, field operator and the supplier of steam. The research showed that the processes of communication and collaboration between the control room , fields and support staff are the key elements of this activity. The study shows that the operators have the autonomy and the elements necessary for work; and that there is continuous investments to improve the technology used and that the operators report sleep disturbances as a result of chronic exposure to night work. The study contributed with proposals for transformation of this activity: with regard to the installation of a area reserved for food in control room, the update the screens of the supervisory current operating condition, the periodic visits by room operators in the field, standardization of production reports, development assistance and standardization of nomenclature of controlling stations steam systems, to improve the conditions of realization of the activity, improve the quality of products produced by operators and contribute to reduce the possibility of slips or shifts in the activity.

Controle em modo dual adaptativo robusto aplicado a um sistema de geração de energia elétrica

Synchronous machines, widely used in energy generation systems, require constant voltage and frequency to obtain good quality of energy. However, for large load variati- ons, it is difficult to maintain outputs on nominal values due to parametric uncertainties, nonlinearities and coupling among variables. Then, we propose to apply the Dual Mode Adaptive Robust Controller (DMARC) in the field flux control loop, replacing the tradi- tional PI controller. The DMARC links a Model Reference Adaptive Controller (MRAC) and a Variable Structure Model Reference Adaptive Controller (VS-MRAC), incorpora- ting transient performance advantages from VS-MRAC and steady state properties from MRAC. Moreover, simulation results are included to corroborate the theoretical studies.

Controle adaptativo com desacoplamento aplicado a um sistema de tanques acoplados MIMO

O controle de sistemas MIMO (Multiple Input Multiple Output) é muitas vezes realizado por várias malhas de controladores clássicos que operam com restrições e apresentam baixo desempenho. Técnicas de controle adaptativo são uma alternativa interessante para aumentar o rendimento desses sistemas, como por exemplo os controladores MRAC (Model Reference Adaptive Control), que quando bem projetados, permitem que a dinâmica da planta seja escolhida de maneira a seguir um modelo de referência. O presente trabalho apresenta uma estratégia de desacoplamento para um sistema MIMO de três tanques acoplados e o projeto de um controlador MRAC para o mesmo.

Controle adaptativo com desacoplamento aplicado a um sistema de tanques acoplados MIMO

O controle de sistemas MIMO (Multiple Input Multiple Output) é muitas vezes realizado por várias malhas de controladores clássicos que operam com restrições e apresentam baixo desempenho. Técnicas de controle adaptativo são uma alternativa interessante para aumentar o rendimento desses sistemas, como por exemplo os controladores MRAC (Model Reference Adaptive Control), que quando bem projetados, permitem que a dinâmica da planta seja escolhida de maneira a seguir um modelo de referência. O presente trabalho apresenta uma estratégia de desacoplamento para um sistema MIMO de três tanques acoplados e o projeto de um controlador MRAC para o mesmo.

Avaliação de produtos naturais no controle de biofilmes formados em sistema dinâmico

The biofilms microbial forms of association are responsible for generating, accelerating and / or induce the process of corrosion. The damage generated in the petroleum industry for this type of corrosion is significatives, representing major investment for your control. The aim of this study was to evaluate such tests antibiograms the effects of extracts of Jatropha curcas and essential oil of Lippia gracilis Schauer on microrganisms isolated from water samples and, thereafter, select the most effective natural product for further evaluation of biofilms formed in dynamic system. Extracts of J. curcas were not efficient on the complete inhibition of microbial growth in tests type antibiogram, and essential oil of L. gracilis Schauer most effective and determined for the other tests. A standard concentration of essential oil of 20 μL was chosen and established for the evaluation of the biofilms and the rate of corrosion. The biocide effect was determined by microbial counts of five types of microorganisms: aerobic bacteria, precipitating iron, total anaerobic, sulphate reducers (BRS) and fungi. The rate of corrosion was measured by loss of mass. Molecular identification and scanning electron microscopy (SEM) were performed. The data showed reduction to zero of the most probable number (MPN) of bacteria precipitating iron and BRS from 115 and 113 minutes of contact, respectively. There was also inhibited in fungi, reducing to zero the rate of colony-forming units (CFU) from 74 minutes of exposure. However, for aerobic and anaerobic bacteria there was no significant difference in the time of exposure to the essential oil, remaining constant. The rate of corrosion was also influenced by the presence of oil. The essential oil of L. gracilis was shown to be potentially effective

Utilizando a porta paralela para controle remoto de um dispositivo

VALENTIM, R. A. M.; NOGUEIRA, I. A.;ROCHA NETO, A. F. Utilizando a porta paralela para controle remoto de um dispositivo. Revista da FARN, Natal, v. 2, p. 103-114, 2002.

Uma arquitetura distribuída de hardware e software para controle de um robô móvel autônomo

BRITTO, Ricardo S.; MEDEIROS, Adelardo A. D.; ALSINA, Pablo J. Uma arquitetura distribuída de hardware e software para controle de um robô móvel autônomo. In: SIMPÓSIO BRASILEIRO DE AUTOMAÇÃO INTELIGENTE,8., 2007, Florianópolis. Anais... Florianópolis: SBAI, 2007.

SISAL - Um sistema supervisório para elevação artificial de petróleo

MEDEIROS, Adelardo A. D. et al. SISAL - Um Sistema Supervisório para Elevação Artificial de Petróleo. In: Rio Oil and Gas Expo Conference, 2006, Rio de Janeiro, RJ. Anais... Rio de Janeiro, 2006.

Impactos da adoção de sistemas de informação no judiciário: pesquisa com usuários do sistema processual virtual em um juizado especial federal

The Information Technology (IT) is increasing his applicability to business, both private and public companies. It is necessary the adequate use of the new technologies and get cooperation and technology acceptance of the system. People tend to resist to the changes, contributing so that the technology is rejected or even it is not recognized as promoting of the changes. This study is relevant and aim to evaluate the impacts of new technologies, considering their users as fundamental factors in the change process. The survey analyzed the advantages and the barriers of the system use in three federal special judicial of Rio Grande do Norte, with data collected in May of 2007, through the application of questionnaires to thirty eight users of the virtual system CRETA. The users' perception was evaluated, under the optics of five variables: efficiency, image, agility, ease of use and quality. Starting from the obtained results, it was evidenced that the implementation of the system felt accordingly the expected and it reached the objectives intended that were: the velocity and efficiency in the path of the lawsuits, larger productivity, resulting in a better quality of the final work introduced to the citizen and proportionate an improvement in the organizational image of the judiciary power