Using serial bluetooth converters as a sensor link in networked control systems

Networked control systems (NCS) are distributed control system in which sensors, actuators and controllers are physically separated and connected through communication networks. NCS represent the evolution of networked control architectures providing greater modularity and control decentralization, ease maintenance and diagnosis and lower cost of implementation. A recent trend in this research topic is the development of NCS using wireless networks which enable interoperability between existing wired and wireless systems. This paper presents the feasibility analysis of using a serial RS-232 to Bluetooth converter as a wireless sensor link in NCS. In order to support this investigation, relevant performance metrics for wireless control applications such as jitter, time delay and messages lost are highlighted and calculated to evaluate the converter capabilities. In addition the control performance of an implemented motor control system using the converter is analyzed. Experimental results led to the conclusion that serial RS-232 Bluetooth converters can be used to implement wireless networked control systems (WNCS) providing transmission rates and closed control loop times which are acceptable for NCS applications. © 2011 IEEE.

Evaluating serial ZigBee devices for application in wireless networked control systems

Networked control systems (NCS) are distributed control system where the sensors, actuators and controllers are physically separated and connected through communication networks. NCS represent the evolution of networked control architectures providing greater modularity and control decentralization, ease maintenance and diagnosis and lower cost of implementation. A recent trend in this research topic is the development of NCS using wireless networks (WNCS) enabling interoperability between existing wired and wireless systems. This paper evaluates a serial RS-232 ZigBee device as a wireless sensor link in NCS. In order to support this investigation, relevant performance metrics for wireless control applications such as jitter, time delay and messages lost are highlighted and calculated to evaluate the device capabilities. In addition the control performance of an implemented motor control system using the device is analyzed. Experimental results led to the conclusion that serial RS-232 ZigBee devices can be used to implement WNCS and the use of this device delay information in the PID controller discretization can improve the control performance of the system. © 2012 IEEE.

Mini-inversores para aproveitamento de energia fotovoltaica, com técnicas de MPPT, sincronismo e conexão com a rede de CA em BT, proteção de ilhamento, gerenciamento da energia e da operação

Pós-graduação em Engenharia Elétrica - FEIS

Estudo da comunicação de um compensador série para rede de distribuição com o centro de controle utilizando tecnologia GPRS

Pós-graduação em Engenharia Elétrica - FEIS

Modelo de virtualização distribuída aplicado ao gerenciamento e replicação de cluster multiuso

Pós-graduação em Ciência da Computação - IBILCE

Análise da área de vulnerabilidade e estabilidade de tensão em sistemas elétricos com a inserção de parques eólicos

A presente dissertação de mestrado avalia os afundamentos e a estabilidade de tensão de um sistema elétrico real com inserção de parques eólicos. Os estudos de afundamentos de tensão servem de base para a determinação das áreas de vulnerabilidade do sistema elétrico, nas quais, por sua vez, são investigados os aspectos referentes à instabilidade de tensão ocasionada pela integração de parques eólicos com geradores assíncronos. Para este fim, é utilizado o programa computacional ANAQUALI, desenvolvido pelo CEPEL (Centro de Pesquisas de Energia Elétrica). No estudo do comportamento dinâmico da tensão decorrente de curto-circuito, no qual o sistema eólico é inserido nas concepções de velocidade fixa e velocidade variável, utiliza-se um programa computacional desenvolvido no aplicativo MATLABTM. Os resultados dessas simulações evidenciam que o sistema eólico de velocidade variável proporciona uma maior margem de estabilidade de tensão ao sistema elétrico, devido à presença do controle de velocidade e de tensão. Estes estudos não são comumente aplicados aos sistemas de geração distribuída, e por isso, esta dissertação contribui também neste aspecto, podendo seus resultados servir de base para o planejamento de centrais cólicas inseridas em sistemas elétricos convencionais.

Implementação e sintonia de um controlador clássico industrial PID: estudo de caso na indústria química

Pós-graduação em Engenharia Mecânica - FEG

Aplicação do conceito de geração distribuída a um sistema fotovoltaico residencial

This work presents a study about distributed generation using photovoltaic systems in the context of smart grids. The characteristics of a Smart Grid and the several aspects this concept involves - distributed generation among them - are discussed. There are also examples of equipment, like smart meters, and of national and international projects. The specificities of distributed generation and the rules and standards necessary in this sort of installation are talked through with focus in the solar energy generation method. Regarding photovoltaic systems, the working principles of the panels are presented, along with its main electrical characteristics and the technologies available. Finally there is a study concerning the sizing of a distributed generation system that involves photovoltaic panels in a residential plant. An analysis of the costs and return of investment period is made about the specific case in consideration.

Disponibilidade em um sistema de arquivos distribuído flexível e adaptável

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Leveraging wireless devices for networked control systems in industrial applications

Networked control systems (NCSs) are distributed control system in which sensors, actuators and controllers are physically separated and connected through communication networks. NCS represent the evolution of networked control architectures providing greater modularity and control decentralization, ease maintenance and diagnosis and lower cost of implementation. A recent trend in this research topic is the development of NCS using wireless networks(WNCS)which enable interoperability between existing wiredand wireless systems. This paper presents the feasibility analysis of using serial to wireless converter as a wireless sensor link in NCS. In order to support this investigation, relevant performance metrics for wireless control applications such as jitter, time delay and messages lost are highlighted and calculated to evaluate the wireless converter capabilities. In addition the control performance of an implemented motor control system using the converter is analyzed. Experimental results led to the conclusion that serial ZigBee device isrecommended against the Bluetooth as it provided better metrics for control applications. However, bothdevices can be used to implement WNCS providing transmission rates and closed control loop times which are acceptable for NCS applications.Moreoverthe use of thewireless device delay in the PID controller discretization can improve the control performance of the system.

Proposta de metodologia para o gerenciamento automático de sistemas fotovoltaicos de geração distribuída

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Managing Large Data Sets Using Support Vector Machines

Hundreds of Terabytes of CMS (Compact Muon Solenoid) data are being accumulated for storage day by day at the University of Nebraska-Lincoln, which is one of the eight US CMS Tier-2 sites. Managing this data includes retaining useful CMS data sets and clearing storage space for newly arriving data by deleting less useful data sets. This is an important task that is currently being done manually and it requires a large amount of time. The overall objective of this study was to develop a methodology to help identify the data sets to be deleted when there is a requirement for storage space. CMS data is stored using HDFS (Hadoop Distributed File System). HDFS logs give information regarding file access operations. Hadoop MapReduce was used to feed information in these logs to Support Vector Machines (SVMs), a machine learning algorithm applicable to classification and regression which is used in this Thesis to develop a classifier. Time elapsed in data set classification by this method is dependent on the size of the input HDFS log file since the algorithmic complexities of Hadoop MapReduce algorithms here are O(n). The SVM methodology produces a list of data sets for deletion along with their respective sizes. This methodology was also compared with a heuristic called Retention Cost which was calculated using size of the data set and the time since its last access to help decide how useful a data set is. Accuracies of both were compared by calculating the percentage of data sets predicted for deletion which were accessed at a later instance of time. Our methodology using SVMs proved to be more accurate than using the Retention Cost heuristic. This methodology could be used to solve similar problems involving other large data sets.

Modeling and simulation of severe slugging with mass transfer effects

A mathematical model and numerical simulations are presented to investigate the dynamics of gas, oil and water flow in a pipeline-riser system. The pipeline is modeled as a lumped parameter system and considers two switchable states: one in which the gas is able to penetrate into the riser and another in which there is a liquid accumulation front, preventing the gas from penetrating the riser. The riser model considers a distributed parameter system, in which movable nodes are used to evaluate local conditions along the subsystem. Mass transfer effects are modeled by using a black oil approximation. The model predicts the liquid penetration length in the pipeline and the liquid level in the riser, so it is possible to determine which type of severe slugging occurs in the system. The method of characteristics is used to simplify the differentiation of the resulting hyperbolic system of equations. The equations are discretized and integrated using an implicit method with a predictor-corrector scheme for the treatment of the nonlinearities. Simulations corresponding to severe slugging conditions are presented and compared to results obtained with OLGA computer code, showing a very good agreement. A description of the types of severe slugging for the three-phase flow of gas, oil and water in a pipeline-riser system with mass transfer effects are presented, as well as a stability map. (C) 2011 Elsevier Ltd. All rights reserved.

Gestión de vídeo distribuido

[ES] El principal objetivo de este Trabajo Final de Grado (TFG) fue la creación de un sistema de gestión de vídeo distribuido utilizando cámaras de videovigilancia IP. Esta propuesta surgió a partir de la idea de ofrecer un acceso simultáneo, tanto online como offline, a las secuencias de vídeo generadas por una red de cámaras IP en un entorno dado. El resultado obtenido fue una infraestructura software ampliable  que ofrece al usuario una serie de funcionalidades con cámaras de red, abstrayéndolo de detalles internos. El trabajo está compuesto por tres elementos claramente diferenciados: integración de cámaras IP, almacenamiento en vídeo y creación del sistema de vídeo distribuido. La integración de cámaras IP tiene como objetivo comunicar al equipo con la cámara de red para la obtención del flujo de imágenes que transmite. Dicha comunicación se establece vía HTTP (Hypertext Transfer Protocol) gracias a la interfaz de programación (API) de la que disponen estos dispositivos. El segundo elemento, el almacenamiento en vídeo, tiene como función guardar las imágenes de la cámara IP en archivos de vídeo. De esta manera se ofrece su posterior visualización en diferido. Finalmente, el sistema de vídeo distribuido permite la reproducción simultánea de múltiples vídeos grabados por la red de cámaras IP. Adicionalmente, vídeos grabados por otros dispositivos también son admitidos. El material desarrollado dispone del potencial necesario para convertirse en una herramienta libre de amplio uso en sistemas UNIX para cámaras IP, así como suponer la base de futuros proyectos relacionados con estos dispositivos.

Mobile TuCSoN: theoretical and technological requirements for TuCSoN's porting over Android mobile devices

Communication and coordination are two key-aspects in open distributed agent system, being both responsible for the system’s behaviour integrity. An infrastructure capable to handling these issues, like TuCSoN, should to be able to exploit modern technologies and tools provided by fast software engineering contexts. Thesis aims to demonstrate TuCSoN infrastructure’s abilities to cope new possibilities, hardware and software, offered by mobile technology. The scenarios are going to configure, are related to the distributed nature of multi-agent systems where an agent should be located and runned just on a mobile device. We deal new mobile technology frontiers concerned with smartphones using Android operating system by Google. Analysis and deployment of a distributed agent-based system so described go first to impact with quality and quantity considerations about available resources. Engineering issue at the base of our research is to use TuCSoN against to reduced memory and computing capability of a smartphone, without the loss of functionality, efficiency and integrity for the infrastructure. Thesis work is organized on two fronts simultaneously: the former is the rationalization process of the available hardware and software resources, the latter, totally orthogonal, is the adaptation and optimization process about TuCSoN architecture for an ad-hoc client side release.