Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 39-40). Also available on the World Wide Web.

Thesis (Ph.D.)--University of Wollongong, 2008. / Typescript. Includes bibliographical references: p. 227-238.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 145-153).

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 125-126). Also available on the World Wide Web.

Thesis (MScEng)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: A unified method is proposed to treat saturation in both Multi-Input-Multi-Output MIMO and Single-Input-Single-Output controllers. This method offers superior performance over existing MIM 0 anti-saturation schemes. The anti-saturation problem is posed as a linear programming problem. A practical and efficient implementation of the algorithm is developed by transforming the problem into its dual linear programming form. The problem, in dual form, is then solved using the dual simplex method rather than the primal simplex method. The nature of the problem when expressed in dual form and the properties of the dual simplex method are harmonised to guarantee an initial basic feasible solution and an optimal bounded final solution in a finite, predictable and minimal number of iterations. The resultant controller never saturates, hence cannot windup. Furthermore the resultant controller always applies the optimal control effort to the plant to minimise the error signal input as follows: • The controller is governed such that while the future free response combined with the present forced response of the controller results in no saturation limits being exceeded, now or at some time in the future, the normal linear response of the controller prevails. • When the future free response combined with the present forced response of the controller will result in a saturation limit being reached, now or at some time in the future, the present time input signal into the controller is optimally governed to prevent the saturation limit from being exceeded at any future time. / AFRIKAANSE OPSOMMING: 'n Metode word voorgestel waarmee versadiging in enkel-inset enkel-uitset en meer-inset meeruitset (MIMU) stelsels beheer kan word. Die metode presteer beter as ander huidige teenversadiging- maatreels vir (MIMU) beheerders. Die teen-versadigings-probleem word as 'n lineere programmeringsprobleem herformuleer. 'n Praktiese en effektiewe implementering van die algoritme word verkry deur die probleem na die duale vorm te transformeer. Die probleem, in duale vorm, word opgelos met die duale simplex metode, in plaas van die direkte metode. Die eienskappe van hierdie formulering is 'n gewaarborgde, aanvanklike, bereikbare oplossing en 'n optimale, begrensde, finale oplossing in 'n eindige, voorspelbare en minimum aantal stappe. Die uiteindelike beheerder versadig nooit nie, en wen gevolglik nie op nie. Die beheerder wend altyd die optimale aanleg-inset aan om die foutsein te minimeer soos volg: • Wanneer die nul-inset gedrag saam met die huidige inset-gedrag geen beperkings nou of in die toekoms saloorskry nie, word geen beperkende aksie geneem nie, en tree die beheerder dus lineer op. • Sodra die toekomstige nul-inset gedrag saam met die huidige inset-gedrag, nou of later versadiging sou veroorsaak, word die huidige inset tot die beheerder optimaal begrens om latere versadiging te voorkom.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2009. / This thesis details the development of linear control systems that allow a vertical take-off and landing unmanned aerial vehicle to perform transitions between vertical and horizontal flight. Two mathematical models are derived for the control system design. A large non-linear model, describing all the dynamics of the aircraft, is linearised in order to perform optimal control using linear quadratic regulator theory. Another model is decoupled using time scale separation to form separate rigid body and point mass dynamics. The decoupled model is controlled using classical control techniques. Simulation results are used to judge the relative performance of the two control schemes in several fields including: Trajectory tracking, sensitivity to parameters, computational complexity and ease of use.

Thesis (Ph. D.)--Auburn University. / Abstract. Vita. Includes bibliographical references (p. 100-106).

Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 109-115). Also available on the World Wide Web.

Este trabalho apresenta um estudo comparativo, o projeto e a implementação de técnicas de controle lineares e não-lineares aplicadas em conversores estáticos de energia elétrica. O principal objetivo deste estudo é controlar, tanto a tensão de saída como o equilíbrio das tensões dos capacitores do barramento CC (Corrente Contínua) de um inversor NPC (Neutral Point Campled) três níveis monofásico. As técnicas de controle utilizadas são o PID (Proporcional-Integral-Derivativo), o ANLPID-GGF (Adaptive Non Linear PID – Gaussian Like Gain Functions), o LQR (Linear Quadratic Regulator) e o SDRE (State Dependent Riccati Equation). O ANLPID-GGF é uma proposta de otimização do controlador PID convencional utilizando funções de ganhos variáveis. Todos os controladores são projetados para manter os mesmos pólos dominantes (autovalores) do sistema em malha fechada de acordo com o modelo do conversor. Desta forma é possível realizar uma comparação mais coerente entre as quatro técnicas de controles estudadas. Com a determinação dos pólos dominantes do sistema é realizado o projeto dos controladores LQR e SDRE por alocação de pólos. Com o projeto por alocação de pólos pode-se evitar os sobre sinais comuns nas aplicações que utilizam controladores LQR e SDRE. Através da análise comparativa entre os quatro controladores, pode-se identificar as características distintas de cada método. Desta forma, também é proposta uma implementação paralela de controladores onde é feita uma associação ponderada entre as leis de controle, dando origem a uma estratégia de controle adaptativo ponderado que melhora o desempenho do sistema, tanto em tempo de resposta quanto na redução dos overshoots. As quatro técnicas de controle utilizadas e a estratégia proposta do controle adaptativo são implementadas em FPGA (Field Programmable Gate Array), utilizando a ferramenta DSP Builder para desenvolvimento e compilação do código HDL (Linguagem de Descrição de Hardware). Resultados de simulações e experimentais são apresentados com o objetivo de validar o desenvolvimento teórico proposto. / This work presents a comparative study, design and implementation of linear and nonlinear control techniques applied on power electronics converters. The main objective of this study is to control the output voltage and the voltage balance between the DC bus voltage capacitors balance of a three level NPC inverter. The control techniques used are the classic PID, the ANLPID-GGF, LQR and SDRE. The Non-Linear PID – Gaussian Gain Functions is considered a new nonlinear control technique used for optimization of the classic linear PID control. Taken the converter transfer function, the designs of the four controllers are set so the operating point of the closed loop system presents the same natural frequency. Thus, the comparative analysis of the performance of each control can be performed more precisely. The pole placement technique is used to design the LQR and SDRE controllers. By means of a comparative analysis of the controllers, it a parallel combination of the designed controllers is also proposed, yielding a weighted adaptive control system. The weighted adaptive controller improves the system performance, both in response time and in controlled magnitudes overshoots reduction. The four control techniques and the strategy an adaptive control proposed are implemented on FPGA, using the DSP Builder tool for the development and compilation the VHDL code. Simulation results are presented in order to validate the proposed theoretical development.

Este trabalho apresenta um estudo comparativo, o projeto e a implementação de técnicas de controle lineares e não-lineares aplicadas em conversores estáticos de energia elétrica. O principal objetivo deste estudo é controlar, tanto a tensão de saída como o equilíbrio das tensões dos capacitores do barramento CC (Corrente Contínua) de um inversor NPC (Neutral Point Campled) três níveis monofásico. As técnicas de controle utilizadas são o PID (Proporcional-Integral-Derivativo), o ANLPID-GGF (Adaptive Non Linear PID – Gaussian Like Gain Functions), o LQR (Linear Quadratic Regulator) e o SDRE (State Dependent Riccati Equation). O ANLPID-GGF é uma proposta de otimização do controlador PID convencional utilizando funções de ganhos variáveis. Todos os controladores são projetados para manter os mesmos pólos dominantes (autovalores) do sistema em malha fechada de acordo com o modelo do conversor. Desta forma é possível realizar uma comparação mais coerente entre as quatro técnicas de controles estudadas. Com a determinação dos pólos dominantes do sistema é realizado o projeto dos controladores LQR e SDRE por alocação de pólos. Com o projeto por alocação de pólos pode-se evitar os sobre sinais comuns nas aplicações que utilizam controladores LQR e SDRE. Através da análise comparativa entre os quatro controladores, pode-se identificar as características distintas de cada método. Desta forma, também é proposta uma implementação paralela de controladores onde é feita uma associação ponderada entre as leis de controle, dando origem a uma estratégia de controle adaptativo ponderado que melhora o desempenho do sistema, tanto em tempo de resposta quanto na redução dos overshoots. As quatro técnicas de controle utilizadas e a estratégia proposta do controle adaptativo são implementadas em FPGA (Field Programmable Gate Array), utilizando a ferramenta DSP Builder para desenvolvimento e compilação do código HDL (Linguagem de Descrição de Hardware). Resultados de simulações e experimentais são apresentados com o objetivo de validar o desenvolvimento teórico proposto. / This work presents a comparative study, design and implementation of linear and nonlinear control techniques applied on power electronics converters. The main objective of this study is to control the output voltage and the voltage balance between the DC bus voltage capacitors balance of a three level NPC inverter. The control techniques used are the classic PID, the ANLPID-GGF, LQR and SDRE. The Non-Linear PID – Gaussian Gain Functions is considered a new nonlinear control technique used for optimization of the classic linear PID control. Taken the converter transfer function, the designs of the four controllers are set so the operating point of the closed loop system presents the same natural frequency. Thus, the comparative analysis of the performance of each control can be performed more precisely. The pole placement technique is used to design the LQR and SDRE controllers. By means of a comparative analysis of the controllers, it a parallel combination of the designed controllers is also proposed, yielding a weighted adaptive control system. The weighted adaptive controller improves the system performance, both in response time and in controlled magnitudes overshoots reduction. The four control techniques and the strategy an adaptive control proposed are implemented on FPGA, using the DSP Builder tool for the development and compilation the VHDL code. Simulation results are presented in order to validate the proposed theoretical development.