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Com o desenvolvimento e disseminação dos protocolos de rede, o surgimento dos chips de ASIC e queda dos preços do silício (estes dois últimos fatores possibilitando com que os sensores e atuadores pudessem ser equipados com interfaces de rede e com isso se tornarem nós independentes em uma rede de controle em tempo real), viabilizaram o desenvolvimento dos sistemas de controle em rede que hoje em dia vêm sendo amplamente utilizados. Juntamente com o aparecimento dos sistemas de controle em rede, novos problemas surgiram sendo um deles o atraso de transporte nas comunicações dos sensores/atuadores/controladores e as conseqüências relacionadas a este fator. Este trabalho tem por objetivo contextualizar sistemas de controle em rede no que concerne novas metodologias de sistemas de controle, escalonamento e apresentar as influências causadas pela comunicação em redes Foundation Fieldbus no desempenho de sistemas de controle. / The development and dissemination of network protocols, the arising of ASIC chip and price drops in silicon (these two last factors allow sensors and actuators be equipped with network interfaces and thus become independent nodes in a real-time control network), make the development of Networked Control Systems possible, which became widely used. New issues - such as an increase in the communication delay among distributed sensors, controller, and actuators have to be handled by designers when developing networked control systems in order to ensure that stability and other usual control performance requirements are met. In this work, the timing behavior of a networked control developed using a Foundation Fieldbus-based network is studied and in particular the impact that communication parameters as jitter, macrocycle, and message scheduling have on control performance metrics like overshoot and settling time are evaluated both theoretically as well as experimentally.

Este trabalho apresenta uma proposta de solução para compensar o atraso variável, característico de redes IP. O preditor de Smith é tradicionalmente usado para compensar atrasos, mas no caso deste tipo de rede um fator importante que pode degradar o controle do sistema são as grandes variações nos atrasos sofridos pelas mensagens. Para tratar este problema, este trabalho baseia-se na criação de uma estrutura de dados de armazenamento para a saída do preditor de Smith, possibilitando a comparação do valor de saída da planta com o valor adequado guardado na estrutura. Para determinação do valor correspondente, este está associado a um índice calculado com o tempo de roundtrip obtido de informações dos pacotes de dados proveniente da planta. Para se chegar a tal solução, foi analisada nas primeiras seções a influência do atraso em malhas de controle e posteriormente um estudo do estado da arte para tipos de controle sobre redes IP. Ao final é apresentada uma análise experimental, demonstrando resultados promissores da aplicação desta proposta. / This work presents a solution to compensate the varying delay, characteristic of IP networks. The Smith predictor is traditionally used to compensate delays but in this type of networks an other important factor that can destabilize the system is the large jitter of the delay. In order to solve this problem, the solution presented here is based on a data structure to save the output from the model of the plant used by the Smith predictor, that make possible to compare the output from the plant with the corresponding value in the structure. In order to take the correspondent value, it is associated to an index which is calculated with the roundtrip obtained from the informations in the packet arrived from the plant. In order to formulate this solution, it was analised in the first sections the influence of the delay in control systems and then a study of the state of art of the control systems over IP networks. At the end, an experimental analise to demonstrate the good result of the application of this solution is presented.

Este trabalho apresenta uma proposta de solução para compensar o atraso variável, característico de redes IP. O preditor de Smith é tradicionalmente usado para compensar atrasos, mas no caso deste tipo de rede um fator importante que pode degradar o controle do sistema são as grandes variações nos atrasos sofridos pelas mensagens. Para tratar este problema, este trabalho baseia-se na criação de uma estrutura de dados de armazenamento para a saída do preditor de Smith, possibilitando a comparação do valor de saída da planta com o valor adequado guardado na estrutura. Para determinação do valor correspondente, este está associado a um índice calculado com o tempo de roundtrip obtido de informações dos pacotes de dados proveniente da planta. Para se chegar a tal solução, foi analisada nas primeiras seções a influência do atraso em malhas de controle e posteriormente um estudo do estado da arte para tipos de controle sobre redes IP. Ao final é apresentada uma análise experimental, demonstrando resultados promissores da aplicação desta proposta. / This work presents a solution to compensate the varying delay, characteristic of IP networks. The Smith predictor is traditionally used to compensate delays but in this type of networks an other important factor that can destabilize the system is the large jitter of the delay. In order to solve this problem, the solution presented here is based on a data structure to save the output from the model of the plant used by the Smith predictor, that make possible to compare the output from the plant with the corresponding value in the structure. In order to take the correspondent value, it is associated to an index which is calculated with the roundtrip obtained from the informations in the packet arrived from the plant. In order to formulate this solution, it was analised in the first sections the influence of the delay in control systems and then a study of the state of art of the control systems over IP networks. At the end, an experimental analise to demonstrate the good result of the application of this solution is presented.

Com o desenvolvimento e disseminação dos protocolos de rede, o surgimento dos chips de ASIC e queda dos preços do silício (estes dois últimos fatores possibilitando com que os sensores e atuadores pudessem ser equipados com interfaces de rede e com isso se tornarem nós independentes em uma rede de controle em tempo real), viabilizaram o desenvolvimento dos sistemas de controle em rede que hoje em dia vêm sendo amplamente utilizados. Juntamente com o aparecimento dos sistemas de controle em rede, novos problemas surgiram sendo um deles o atraso de transporte nas comunicações dos sensores/atuadores/controladores e as conseqüências relacionadas a este fator. Este trabalho tem por objetivo contextualizar sistemas de controle em rede no que concerne novas metodologias de sistemas de controle, escalonamento e apresentar as influências causadas pela comunicação em redes Foundation Fieldbus no desempenho de sistemas de controle. / The development and dissemination of network protocols, the arising of ASIC chip and price drops in silicon (these two last factors allow sensors and actuators be equipped with network interfaces and thus become independent nodes in a real-time control network), make the development of Networked Control Systems possible, which became widely used. New issues - such as an increase in the communication delay among distributed sensors, controller, and actuators have to be handled by designers when developing networked control systems in order to ensure that stability and other usual control performance requirements are met. In this work, the timing behavior of a networked control developed using a Foundation Fieldbus-based network is studied and in particular the impact that communication parameters as jitter, macrocycle, and message scheduling have on control performance metrics like overshoot and settling time are evaluated both theoretically as well as experimentally.

Com o desenvolvimento e disseminação dos protocolos de rede, o surgimento dos chips de ASIC e queda dos preços do silício (estes dois últimos fatores possibilitando com que os sensores e atuadores pudessem ser equipados com interfaces de rede e com isso se tornarem nós independentes em uma rede de controle em tempo real), viabilizaram o desenvolvimento dos sistemas de controle em rede que hoje em dia vêm sendo amplamente utilizados. Juntamente com o aparecimento dos sistemas de controle em rede, novos problemas surgiram sendo um deles o atraso de transporte nas comunicações dos sensores/atuadores/controladores e as conseqüências relacionadas a este fator. Este trabalho tem por objetivo contextualizar sistemas de controle em rede no que concerne novas metodologias de sistemas de controle, escalonamento e apresentar as influências causadas pela comunicação em redes Foundation Fieldbus no desempenho de sistemas de controle. / The development and dissemination of network protocols, the arising of ASIC chip and price drops in silicon (these two last factors allow sensors and actuators be equipped with network interfaces and thus become independent nodes in a real-time control network), make the development of Networked Control Systems possible, which became widely used. New issues - such as an increase in the communication delay among distributed sensors, controller, and actuators have to be handled by designers when developing networked control systems in order to ensure that stability and other usual control performance requirements are met. In this work, the timing behavior of a networked control developed using a Foundation Fieldbus-based network is studied and in particular the impact that communication parameters as jitter, macrocycle, and message scheduling have on control performance metrics like overshoot and settling time are evaluated both theoretically as well as experimentally.

Este trabalho apresenta uma proposta de solução para compensar o atraso variável, característico de redes IP. O preditor de Smith é tradicionalmente usado para compensar atrasos, mas no caso deste tipo de rede um fator importante que pode degradar o controle do sistema são as grandes variações nos atrasos sofridos pelas mensagens. Para tratar este problema, este trabalho baseia-se na criação de uma estrutura de dados de armazenamento para a saída do preditor de Smith, possibilitando a comparação do valor de saída da planta com o valor adequado guardado na estrutura. Para determinação do valor correspondente, este está associado a um índice calculado com o tempo de roundtrip obtido de informações dos pacotes de dados proveniente da planta. Para se chegar a tal solução, foi analisada nas primeiras seções a influência do atraso em malhas de controle e posteriormente um estudo do estado da arte para tipos de controle sobre redes IP. Ao final é apresentada uma análise experimental, demonstrando resultados promissores da aplicação desta proposta. / This work presents a solution to compensate the varying delay, characteristic of IP networks. The Smith predictor is traditionally used to compensate delays but in this type of networks an other important factor that can destabilize the system is the large jitter of the delay. In order to solve this problem, the solution presented here is based on a data structure to save the output from the model of the plant used by the Smith predictor, that make possible to compare the output from the plant with the corresponding value in the structure. In order to take the correspondent value, it is associated to an index which is calculated with the roundtrip obtained from the informations in the packet arrived from the plant. In order to formulate this solution, it was analised in the first sections the influence of the delay in control systems and then a study of the state of art of the control systems over IP networks. At the end, an experimental analise to demonstrate the good result of the application of this solution is presented.

Master thesis is focused on the philosophy of design adaptive controller. In the theoretic part are described parts of the adaptive controller, which belongs parts as online identification by recursive least-squares method and PSD controller, which can set its parameters according to identified system (use Z-N method). The part of control system with transport delay is situated at the conclusion of the theoretic part, there are focused on Smith predictor. Practical part is focused on verification of all algorithms, which was performed on models and real systems.

Master thesis is focused on the philosophy of design adaptive controller. In the theoretic part are described parts of the adaptive controller, which belongs parts as online identification by recursive least-squares method and PSD controller, which can set its parameters according to identified system (use Z-N method). The part of control system with transport delay is situated at the conclusion of the theoretic part, there are focused on Smith predictor. Practical part is focused on verification of all algorithms, which was performed on models and real systems.

In this dissertation, an assessment is conducted of the potential benefits of combined heat and power (CHP) based district energy (DE) grids in energy systems of different scale having significant fossil fuel fired electrical generation capacity. Three studies are included in the research. In the first study, the potential benefits of expanding CHP-based DE grids in a large scale energy system are investigated. The impacts of expanding wind power systems are also investigated and a comparison between these technologies is made with respect to fossil fuel utilization and CO2 emissions. A model is constructed and five scenarios are evaluated with the EnergyPLAN software taking the province of Ontario, Canada as the case study. Results show that reductions in fuel utilization and CO2 emissions of up to 8.5% and 32%, respectively, are possible when switching to an energy system comprising widespread CHP-based DE grids. In the second study, a high temporal resolution numerical model (i.e. the SS-VTD model) is developed that is capable of rapidly calculating distribution losses in small scale variable flow DE grids with low error and computational intensity. The SS-VTD model is validated by comparing simulated temperature data with measured temperature data from an existing network. The Saanich DE grid, located near Victoria, Canada, is used as the case study for validation. In the third study, the potential benefits of integrating high penetrations of renewable energy via a power-to-heat plant in a small scale CHP-based DE grid are investigated. The impacts of switching to a CHP-based DE grid equipped with an electric boiler plant versus a conventional wave power system are compared with respect to fossil fuel utilization and CO2 emissions. The SS-VTD model is used to conduct the study. The energy system of the Hot Springs Cove community, located on the west coast of Vancouver Island, Canada is used as the case study in the analysis. Results show that relative to the conventional wave power system, reductions in fuel utilization and CO2 emissions of up to 47% are possible when switching to a CHP-based DE grid. / Graduate