Thesis submitted in compliance with the requirements for the Master's Degree in Technology: Electrical Engineering - Light Current, Durban University of Technology, Department of Electronic Engineering, 2008. / Linear control systems can be easily tuned using classical tuning techniques such as the Ziegler-Nichols and Cohen-Coon tuning formulae. Empirical studies have found that these conventional tuning methods result in an unsatisfactory control performance when they are used for processes experiencing the negative destabilizing effects of strong nonlinearities. It is for this reason that control practitioners often prefer to tune most nonlinear systems using trial and error tuning, or intuitive tuning. A need therefore exists for the development of a suitable tuning technique that is applicable for a wide range of control loops that do not respond satisfactorily to conventional tuning. Emerging technologies such as Swarm Intelligence (SI) have been utilized to solve many non-linear engineering problems. Particle Swarm Optimization (PSO), developed by Eberhart and Kennedy (1995), is a sub-field of SI and was inspired by swarming patterns occurring in nature such as flocking birds. It was observed that each individual exchanges previous experience, hence knowledge of the “best position” attained by an individual becomes globally known. In the study, the problem of identifying the PID controller parameters is considered as an optimization problem. An attempt has been made to determine the PID parameters employing the PSO technique. A wide range of typical process models commonly encountered in industry is used to assess the efficacy of the PSO methodology. Comparisons are made between the PSO technique and other conventional methods using simulations and real-time control.

Thesis (Ph.D.)--Memorial University of Newfoundland, 1999. / Bibliography: leaves 182-191.

Thesis (M. Phil.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 111-127). Also available in print.

Made available in DSpace on 2014-12-02T11:16:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-18Bitstream added on 2014-12-02T11:21:17Z : No. of bitstreams: 1 000792343.pdf: 1375935 bytes, checksum: eead910c412b75624061ec463da3bc4e (MD5) / Devido às necessidades de se automatizar parte de seu processo para garantir os resultados projetados e obter maior segurança nas operações, desenvolveu-se um projeto para a implementação de um sistema para o controle da pressão interna de um reator, em uma indústria química. Através de minuciosos estudos sobre estrutura de controle PID e métodos clássicos de sintonia de Ziegler e Nichols, e após analisar em ambientes de simulação, o comportamento da resposta da planta diante das ações de controle, foi proposto um sistema completo, contendo um modelo sintonizado de controlador PID (Proporcional, Integrativo e Derivativo) para ser integrado no Sistema Digital de Controle Distribuído (SDCD), existente na empresa, com estratégia de controle em faixa dividida. Tal sistema foi aplicado no processo real e mostrou-se eficiente e de fácil aplicabilidade, trazendo resultados satisfatórios no controle da pressão e imediatas justificativas para o investimento / Due to the need to automate part of the process to ensure the projected results and to get more operational safety, it was developed a project for the implementation of a system for internal pressure control of a reactor in a chemical industry. Through detailed studies of control structure PID and Ziegler and Nichols classic tuning methods, and after analyzing in simulation environments the behavior of plant response on control actions, it was proposed a complete system, containing a controller tuned model PID (Proportional, Integrative and Derivative) to be integrated into the Digital Distributed Control System, belonging the company, with split range control strategy. This system was applied to the current process and it was proved to be efficient and easily applied, bringing satisfactory results in pressure control and immediate justification for the investment

Made available in DSpace on 2014-06-11T19:22:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-08-31Bitstream added on 2014-06-13T20:09:41Z : No. of bitstreams: 1 kozan_rf_me_ilha.pdf: 1513619 bytes, checksum: 4155bafb25f3608bef16f25ae4874e56 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A Estimulação Elétrica Funcional (FES - Functional Electrical Stimulation) tem sido utilizada na ajuda do restabelecimento de funções motoras em pacientes hemiplégicos e paraplégicos. A estimulação aplicada em níveis adequados pode ser tão eficaz no fortalecimento muscular quanto uma contração muscular voluntária. Este trabalho faz parte de um projeto multidisciplinar que integra controle e instrumentação que tem por objetivo controlar os movimentos dos membros inferiores de pacientes paraplégicos. Utilizando um processador digital de sinais e um modelo matemático linear simplificado efetuou-se a implementação de um sistema de controle em malha fechada, por meio de um controlador PID, da posição da perna de uma pessoa hígida. Implementou-se também o circuito lógico de um estágio formador de onda de um Estimulador Elétrico Neuromuscular, utilizando LabVIEW. Os parâmetros de estirnulação podem ser alterados com agilidade e facilidade. Resultados experimentais ficaram muito próximos aos obtidos através das simulações. O sistema de controle conseguiu estabilizar a posição da perna de pessoas hígidas no ângulo desejado / The Functional Electrical Stimulation (FES) has been used to help restore motor functions of hemiplegic and paraplegic patients. The FES applied at appropriate levels can be as effective in muscle strengthening as a voluntary muscle contraction. This work is part of a multidisciplinary project that integrates control systems and instrumentation to control the movements of the lower limbs of paraplegic patients. Using a digital signal processor and a simplified linear mathematical model, a PID controller was implemented with the aim of controlling the position of the leg of healthy patients. The Neuromuscular Electrical Stimulator logic circuit was implemented using LabVIEW. The stimulation parameters can be changed easily and quickly. The experimental results were very elose to those simulated. The control system was able to stabilize the position of the leg of a patient at a desired angle

Thesis submitted in fulfillment of the requirements for the degree Master of Technology: Electrical Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology 2014 / A new control strategy for control of the nonlinear process of Dissolved Oxygen (DO) concentration in the aerobic tank of wastewater treatment process is proposed. It provides means to improve the performance of the Linear Proportional Integration and Derivative (LPID) controller by extending it to a Nonlinear Proportional Integration and Derivative (NLPID) controller. The aim of the thesis is to develop methods, algorithms and software for design, simulation, and programmable logic controller (PLC) implementation of NLPID controllers in order to control the nonlinear process of dissolved oxygen. The thesis investigates the possibilities the widely used in theory and industry methods for the design of the LPID controllers for linear processes as Ziegler- Nichols and Pole Placement, to be applied to the design of NLPID controllers for the nonlinear process of DO concentration. Three cases are considered: Case 1: Application of the values of the parameters the linear PID controller designed by the Ziegler-Niched method for the linearized DO process model to be used as parameters of the nonlinear PID controllers to control the DO nonlinear process. Case 2: Application of the values of the parameters of the linear PID controller designed by the Pole placement method for the linearized DO process model, to be used as parameters of the nonlinear PID controller to control the nonlinear DO process. Case 3: Novel, proposed in the thesis, method based on the Pole placement method for direct design of the parameters of the linear and nonlinear PID controllers to control the nonlinear DO process. Software is developed to simulate in MATLAB environment the behavior of the closed loop DO process for the considered cases of controller designs. The results of the simulations show that in the Case1 and the Case 2 it is not possible to use the values of the LPID controller parameters designed for the linearized DO process, directly to control the nonlinear process by the NPID controllers. Additional tuning for some of the parameters is needed. The simulation in the Case 3 shows the excellent behaviors of the closed loop system for all linear and nonlinear PID controllers which prove that the new method is effective and applicable. Real-time simulations of the closed loop system are done in a TwinCAT 3 simulation environment of the Bechkoff EX5020 PLC. The deliverables of the thesis are applicable to many type nonlinear processes in chemical, manufacturing, and other industries.

Orientador: Victor Orlando Gamarra Rosado / Banca: José Elias Tomazini / Banca: Luiz Eduardo Nicolini do Patrocínio Nunes / Resumo : Devido às necessidades de se automatizar parte de seu processo para garantir os resultados projetados e obter maior segurança nas operações, desenvolveu-se um projeto para a implementação de um sistema para o controle da pressão interna de um reator, em uma indústria química. Através de minuciosos estudos sobre estrutura de controle PID e métodos clássicos de sintonia de Ziegler e Nichols, e após analisar em ambientes de simulação, o comportamento da resposta da planta diante das ações de controle, foi proposto um sistema completo, contendo um modelo sintonizado de controlador PID (Proporcional, Integrativo e Derivativo) para ser integrado no Sistema Digital de Controle Distribuído (SDCD), existente na empresa, com estratégia de controle em faixa dividida. Tal sistema foi aplicado no processo real e mostrou-se eficiente e de fácil aplicabilidade, trazendo resultados satisfatórios no controle da pressão e imediatas justificativas para o investimento / Abstract: Due to the need to automate part of the process to ensure the projected results and to get more operational safety, it was developed a project for the implementation of a system for internal pressure control of a reactor in a chemical industry. Through detailed studies of control structure PID and Ziegler and Nichols classic tuning methods, and after analyzing in simulation environments the behavior of plant response on control actions, it was proposed a complete system, containing a controller tuned model PID (Proportional, Integrative and Derivative) to be integrated into the Digital Distributed Control System, belonging the company, with split range control strategy. This system was applied to the current process and it was proved to be efficient and easily applied, bringing satisfactory results in pressure control and immediate justification for the investment / Mestre

Orientador: Aparecido Augusto de Carvalho / Banca: Erica Regina Marani Daruichi Machado / Banca: Ruberlei Gaino / Resumo: A Estimulação Elétrica Funcional (FES - Functional Electrical Stimulation) tem sido utilizada na ajuda do restabelecimento de funções motoras em pacientes hemiplégicos e paraplégicos. A estimulação aplicada em níveis adequados pode ser tão eficaz no fortalecimento muscular quanto uma contração muscular voluntária. Este trabalho faz parte de um projeto multidisciplinar que integra controle e instrumentação que tem por objetivo controlar os movimentos dos membros inferiores de pacientes paraplégicos. Utilizando um processador digital de sinais e um modelo matemático linear simplificado efetuou-se a implementação de um sistema de controle em malha fechada, por meio de um controlador PID, da posição da perna de uma pessoa hígida. Implementou-se também o circuito lógico de um estágio formador de onda de um Estimulador Elétrico Neuromuscular, utilizando LabVIEW. Os parâmetros de estirnulação podem ser alterados com agilidade e facilidade. Resultados experimentais ficaram muito próximos aos obtidos através das simulações. O sistema de controle conseguiu estabilizar a posição da perna de pessoas hígidas no ângulo desejado / Abstract: The Functional Electrical Stimulation (FES) has been used to help restore motor functions of hemiplegic and paraplegic patients. The FES applied at appropriate levels can be as effective in muscle strengthening as a voluntary muscle contraction. This work is part of a multidisciplinary project that integrates control systems and instrumentation to control the movements of the lower limbs of paraplegic patients. Using a digital signal processor and a simplified linear mathematical model, a PID controller was implemented with the aim of controlling the position of the leg of healthy patients. The Neuromuscular Electrical Stimulator logic circuit was implemented using LabVIEW. The stimulation parameters can be changed easily and quickly. The experimental results were very elose to those simulated. The control system was able to stabilize the position of the leg of a patient at a desired angle / Mestre

Orientador: Jose Geraldo Pena de Andrade / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-11T05:54:27Z (GMT). No. of bitstreams: 1 Giacomini_MarcosRoberto_D.pdf: 3148192 bytes, checksum: 975bbc84589e07811d6b2dcf58814dfe (MD5) Previous issue date: 2007 / Resumo: Este trabalho apresenta uma nova proposta para obter os parâmetros do regulador de uma turbina hidráulica, com o objetivo de melhorar o controle operacional de uma usina hidrelétrica. Dentre os diversos métodos existentes, o método de Ziegler-Nichols mostra-se adequado porque na determinação dos parâmetros do regulador efetuam-se simulações que consideram todo o comportamento hidráulico da instalação e da máquina. A partir de inúmeras simulações, para a estabilização da rotação adimensional, variando o tempo da água, o tempo da máquina e a rejeição, percebeu-se que os coeficientes utilizados no método de Ziegler-Nichols não apresentavam bons resultados em algumas situações, deixando evidente a necessidade de uma adequação. As equações propostas neste trabalho permitem a obtenção de valores mais adequados para as constantes proporcional, integral e derivativa através dos valores da constante proporcional última e do período último, como já utilizado no método de Ziegler-Nichols, em função do tempo da água, do tempo da máquina e da rejeição da potência / Abstract: This work presents a new proposal to obtain the parameters of the regulator of a hydraulic turbine, looking for the goal to increase the operational control of a hydroelectric power plant. Among many existing methods, the Ziegler-Nichols shows itself adequate because in the determination of the parameters of the regulator simulations are carried out witch consider all the hydraulic behavior of the installation and the machine. From many simulations, to the adimensional rotation stabilization, varying the water time, the machine time and the rejection, it was realized that the coefficients used in the Ziegler-Nichols method weren't presenting good results in some situations, leaving evident the needy of an adaptation. The equations suggested in this work allow obtaining more adequate values to the proportional, integral and derivative constants, through the constant last proportional values and the last period, as already used in the Ziegler-Nichols method in function of the water time, the machine time and the power rejection / Doutorado / Recursos Hidricos / Doutor em Engenharia Civil

Industry 4.0 holds many promises for manufacturers; however, a shortage of qualified employees has prevented a swift adoption of the revolution's new technologies. Engineer and Economist Klaus Schwab argues Education 4.0 is the key to addressing the employee shortage and preparing future generations for the shifting labor market. To support Education 4.0, classes must allow students to engage emerging technologies that help bridge Operational Technology (OT) and Informational Technology (IT). The thesis detailed an educational laboratory that demonstrates the application of data analytics (an IT tool) and optimize the performance of a cyber-physical system composed of industrial (OT) components. The lab experience focuses on a disc's controlled positioning (levitating) using a PLC-based PID controller and a VFD. The activity requires students to capture data of a moving discs, create a machine learning function representing the disc's movement, and use the machine learning function for classification and PID optimization problems. A comparative analysis of a PID cycle ensures a regressions model accurately represents the physical model using measurements including peak-overshoot, rise time, settling time, and the flight plots' Means of their Squared Error. Further, the study examines multiple ML models each built using various features to identify the systems relevant and redundant data.<br>