Motivation behind this master dissertation is to introduce a novel study called " A fuzzy logic micro-controller enabled system for the monitoring of micro-climatic parameters of a greenhouse" which is capable of intelligently monitoring and controlling the greenhouse climate conditions in a preprogrammed manner. The proposed system consists of three stations: Sensor Station, Coordinator Station, and Central Station. To allow for better monitoring of the climate condition in the greenhouse, fuzzy logic controller is embedded in the system as the system becomes more intelligent with fuzzy decision making. The sensor station is equipped with several sensor elements such as MQ-7 (Carbon monoxide sensor), DHT11 (Temperature and humidity sensor), LDR (light sensor), grove moisture sensor (soil moisture sensor). The communication between the sensor station and the coordinator station is achieved through XBee wireless modules connected to the Arduino Mega and the communication between coordinator station and the central station is also achieved via XBee wireless modules connected to the Arduino Mega. The experiments and tests of the system were carried out at one of IKHALA TVET COLLEGE’s greenhouses that is used for learning purposes by students studying agriculture at the college. The purpose of conducting the experiments at the college’s green house was to determine the functionality and reliability of the designed wireless sensor network using ZigBee wireless technology. The experiment result indicated that XBee modules could be used as one solution to lower the installation cost, increase flexibility and reliability and create a greenhouse management system that is only based on wireless nodes. The experiment result also showed that the system became more intelligent if fuzzy logic was used by the system for decision making. The overall system design showed advantages in cost, size, power, flexibility and intelligence. It is trusted that the results of the project will give the chance for further research and development of a low cost greenhouse monitoring system for commercial use. / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)

Submitted by DIOGO RAMALHO DE OLIVEIRA null (diogo.oliveira.ee@gmail.com) on 2017-06-22T14:35:42Z No. of bitstreams: 1 Tese_Diogo.pdf: 2317981 bytes, checksum: fa048901c893f57ba87ceec19383ae14 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-06-22T17:28:20Z (GMT) No. of bitstreams: 1 oliveira_dr_dr_ilha.pdf: 2317981 bytes, checksum: fa048901c893f57ba87ceec19383ae14 (MD5) / Made available in DSpace on 2017-06-22T17:28:20Z (GMT). No. of bitstreams: 1 oliveira_dr_dr_ilha.pdf: 2317981 bytes, checksum: fa048901c893f57ba87ceec19383ae14 (MD5) Previous issue date: 2017-05-31 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Esta tese propõe projetos de controle H∞ chaveado para uma classe de sistemas não lineares incertos descritos por modelos fuzzy Takagi-Sugeno (T-S) com funções de pertinência desconhecidas. Os projetos de controle necessitam somente dos limites inferiores e superiores das não linearidades do sistema, que podem depender de parâmetros incertos da planta. Em diversas aplicações práticas, em virtude das restrições operacionais dos equipamentos, no projeto de controle é necessário considerar que a lei de controle está sujeita à saturação do atuador. Primeiramente, utilizando uma metodologia encontrada na literatura para resolver o problema da saturação do atuador, propõe-se uma lei de controle chaveada que escolhe um ganho do controlador de realimentação do vetor de estado, que pertence a um conjunto de ganhos conhecidos, que minimiza a derivada da função de Lyapunov do tipo quadrática. Este procedimento elimina a necessidade de encontrar as expressões das funções de pertinência para implementar a lei de controle, garante um desempenho H∞ ao sistema realimentado e assegura que as trajetórias do vetor de estado permanecem dentro de uma região de operação na qual o modelo fuzzy T-S é válido. Adicionalmente, adota-se uma outra metodologia para resolver o problema da saturação do atuador, que utiliza o sinal de controle para compor um vetor de estado expandido. Desta forma, os limites do sinal de controle fazem parte da região de operação na qual o sistema não linear incerto é exatamente representado via modelos fuzzy T-S. Uma lei de controle chaveada, que utiliza a realimentação do vetor de estado expandido, é proposta. As condições de projeto evitam a presença de uma possível descontinuidade do sinal de controle, eliminam a necessidade de obter as expressões das funções de pertinência para implementar a lei de controle, garantem um desempenho H∞ e asseguram que as trajetórias do vetor de estado e do sinal de controle permanecem dentro de uma região de operação na qual o modelo fuzzy T-S é válido. Por fim, três exemplos são apresentados. O primeiro exemplo estuda o controle de um sistema caótico denominado Lorenz. Mostra que, para distúrbios de grande magnitude, os procedimentos propostos apresentaram melhores resultados do que os obtidos com outro método recentemente encontrado na literatura, que considera o pleno acesso às funções de pertinência. No segundo exemplo, uma implementação prática em um sistema de controle de uma suspensão ativa de bancada, considerando uma mola não linear e falha no atuador, confirma a eficácia da abordagem proposta. O último exemplo utiliza um pêndulo invertido para abordar o problema de controle considerando a estabilidade local do sistema. As simulações ilustram que o esquema proposto, que utiliza o vetor de estado expandido, é capaz de evitar uma possível descontinuidade do sinal de controle. / This thesis proposes local H∞ switched control designs for a class of uncertain nonlinear plants described by Takagi-Sugeno (T-S) fuzzy models with unknown membership functions. The control designs require only the lower and upper bounds of the system nonlinearities and of the system linear parameters, which can depend on uncertain parameters. In practical applications, due to the operational restrictions of the equipments, in the control design, it is necessary to consider that the control law is subject to actuator saturation. First, using a methodology found in the literature to solve the actuator saturation problem, one proposes a switched control law that chooses a state-feedback controller gain, which belongs to a given set of gains, that minimizes the time derivative of a quadratic Lyapunov function. This procedure eliminates the necessity of finding the membership function expressions to implement the control law, guarantees an H∞ performance and ensures that the state trajectory remains within a region in which the T-S fuzzy model is valid. In addition, the actuator saturation problem is approached with another methodology, using the control signal to compose an extended state vector. Then, the region in which the uncertain nonlinear system is exactly represented via T-S fuzzy models is composed by the bounds of the control signal. A switched control law, which chooses an extended state-feedback controller gain, is proposed. The design conditions avoid the presence of a possible discontinuity of the control signal, eliminate the necessity of finding the membership function expressions to implement the control law, guarantee an H∞ performance and ensure that the state trajectory and the control signal remain within a region in which the T-S fuzzy model is valid. Finally, three examples are presented. The first example studies the control of a chaotic Lorenz system. It shows that, for disturbances with large magnitude, the proposed procedures provided better results than the obtained with another recent method found in the literature, that considers full access to the membership functions. In the second example, a practical implementation of an active suspension control system, considering a nonlinear spring and an actuator fault, confirms the effectiveness of the proposed approach. The last example uses an inverted pendulum system to address the local stability control problem. The simulations illustrate that the control scheme, which uses the extended state vector, is able to avoid a possible discontinuity of the control signal. / CNPq: 142035/2013-0

在資料分析上，調查者通常需要決定，不同的樣本是否可被視為來自相同的母體。一般最常使用的統計量為Pearson’s 統計量。然而，傳統的統計方法皆是利用二元邏輯觀念來呈現。如果我們想要用模糊邏輯的概念來做樣本調查，此時，使用傳統 檢定來分析這些模糊樣本資料是否仍然適當？透過這樣的觀念，我們使用傳統統計方法，找出一個能處理這些模糊樣本資料的公式，稱之為模糊 。結果顯示，此公式可用來檢定，模糊樣本資料在不同母體下機率的一致性。 / In the analysis of research data, the investigator often needs to decide whether several independent samples may be regarded as having come from the same population. The most commonly used statistic is Pearson’s statistic. However, traditional statistics reflect the result from a two-valued logic concept. If we want to survey sampling with fuzzy logic concept, is it still appropriate to use the traditional -test for analysing those fuzzy sample data? Through this concept, we try to use a traditional statistic method to find out a formula, called fuzzy , that enables us to deal with those fuzzy sample data. The result shows that we can use the formula to test hypotheses about probabilities of various outcomes in fuzzy sample data.

The following diploma thesis focuses on processing of uncertain information in databases. Uncertain information represents vague customer requests during laptop choice in classic shop purchasing. Effort of the work is to develop a modern e-shop application selling laptops, which is based on expert fuzzy system helping customers to choose a laptop without knowledge of technical specifications and current trends.