Дисертації з теми "Switched linear/nonlinear systems"
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Lim, Hong Sun. "Design and Control of A Ropeless Elevator with Linear Switched Reluctance Motor Drive Actuation Systems." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/26541.
Повний текст джерелаPh. D.
Suto, Alan Pereira 1989. "Análise de estabilidade e desempenho H2 de sistemas do tipo Lur'e com comutação." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265797.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: Esta dissertação trata do controle H2 de sistemas com comutação do tipo Lur¿e baseado no critério generalizado de Popov. Mais especificamente, uma nova regra de comutação dependente do estado e da entrada externa é proposta de tal forma a assegurar estabilidade assintótica global e um custo garantido H2 de desempenho. Esta nova estratégia de comutação é o ponto chave para a generalização do célebre critério de Popov. Como no caso de sistemas invariantes no tempo, propomos um teste de estabilidade baseado no domínio da frequência expresso em termos de uma certa combinação convexa das matrizes de espaço de estado dos subsistemas. Ademais, este teste leva em conta a inclusão de um índice de desempenho H2 cujo estudo, no presente contexto, é inédito na literatura. Os resultados teóricos obtidos são aplicados no controle de uma suspensão semi-ativa automotiva evidenciando a validade e a eficiência da função de comutação proposta
Abstract: This Master¿s dissertation deals with H2 control design of Lur¿e-type switched systems based on the generalized Popov criterion. More specifically, a novel state-input dependent switching rule is proposed in order to assure global asymptotic stability and an H2 guaranteed cost. This new switching strategy is the key issue to generalize the celebrated Popov criterion. Likewise the case of time invariant systems, we propose a frequency domain stability test that is expressed in terms of a certain convex combination of the subsystems state space matrices. Moreover, this test takes into account an H2 performance index whose study, in the present context, is new in the literature. The theoretical results are used to the control design of a car semiactive suspension and to put in evidence the validity and the efficiency of the proposed switching function
Mestrado
Mecanica dos Sólidos e Projeto Mecanico
Mestre em Engenharia Mecânica
Ramos, Igor Thiago Minari. "Projetos de controladores robustos chaveados para sistemas não lineares baseados na decomposição em soma de quadrados /." Ilha Solteira, 2018. http://hdl.handle.net/11449/154369.
Повний текст джерелаResumo: Neste trabalho são propostos novos métodos de controle chaveado para uma classe de sistemas não lineares incertos utilizando a decomposição em soma de quadrados. Inicialmente é apresentada uma revisão dos conceitos e projetos de controladores baseados em desigualdades matriciais lineares (do inglês Linear Matrix Inequalities - LMIs) e a decomposição em soma de quadrados (do inglês Sum of Squares - SOS), buscando evidenciar as diferenças e vantagens das metodologias para a área de controle. Comumente são utilizados modelos fuzzy para realizar a análise da estabilidade e projeto de controladores para sistemas não lineares, e estes modelos podem ser classificados de acordo com a parte consequente linear ou polinomial. Busca-se neste trabalho evidenciar as diferenças entre os dois modelos fuzzy e a metodologia para projeto de controladores. Para o caso de sistemas cujas dinâmicas podem ser descritas apenas por funções polinomiais, serão consideradas incertezas politópicas. Então, visando flexibilizar o projeto utilizando um controlador composto por um único ganho polinomial e aumentar a região de factibilidade, são propostos controladores com ganhos polinomiais chaveados. O objetivo desta lei de chaveamento é minimizar a derivada da função de Lyapunov empregada no projeto. Considerando uma classe de sistemas não lineares mais geral, são propostos controladores com ganhos chaveados para modelos fuzzy polinomiais. A metodologia proposta não necessita do conhecimento das funções de ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In this manuscript new control methods are proposed for a class of uncertain nonlinear systems using a sum of squares decomposition. Initially is presented a revision of concepts and control design procedures based on Linear Matrix Inequalities (LMIs) and on sum of squares (SOS) evidencing the differences and advantages of these methodologies in the control system design. Fuzzy models are commonly used to perform stability analysis and controller design for nonlinear systems, and can be classified by a linear or polynomial consequent model. A goal of this dissertation is to compare these two methodologies in the control system design of a class of uncertain nonlinear systems. For the case of systems whose dynamics can be described only by polynomial functions will be also considered polytopic uncertainty. Therefore, in order to make the design more flexible than that obtained with only one controller with polynomial gain and increase the feasibility region, a new procedure for designing controllers with switched polynomial gains is proposed. The purpose of this switching law is to minimize the time derivative of the Lyapunov function employed in the design. For a more general class of nonlinear systems, controllers with switched gains for polynomial fuzzy models are proposed. The proposed methodology does not require the knowledge of the membership functions for an implementation of the control law. This fact is an important advantage over the many methods that consider avail... (Complete abstract click electronic access below)
Mestre
Mayo, Maldonado Jonathan. "Switched linear differential systems." Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/383678/.
Повний текст джерелаBabaali, Mohamed. "Switched Linear Systems: Observability and Observers." Diss., Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-04122004-073020/unrestricted/babaali%5Fmohamed%5F200405%5Fphd.pdf.
Повний текст джерелаVerriest, Erik, Committee Member ; Wardi, Yorai, Committee Member ; Yezzi, Anthony, Committee Member ; Wang, Yang, Committee Member ; Egerstedt, Magnus, Committee Chair. Vita. Includes bibliographical references (leaves 80-85).
Alves, Uiliam Nelson Lendzion Tomaz. "Controle chaveado e chaveado suave de sistemas não lineares incertos via modelos fuzzy T-S." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/152448.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O controle chaveado pode ser eficientemente utilizado no controle de sistemas fuzzy TakagiSugeno (T-S) incertos, que possuam funções de pertinência incertas e modelos locais conhecidos. Como estes sistemas fuzzy podem representar exatamente uma classe de sistemas não lineares incertos em uma região do espaço de estados, é interessante utilizá-los para descrever sistemas não lineares, usando no projeto do controlador o modelo fuzzy que descreve exatamente o sistema não linear. Porém, como a representação através de combinação convexa obtida é válida apenas em uma região do espaço de estados, garantias de que o estado do sistema permaneça nessa região devem ser obtidas. Neste trabalho são propostas condições que garantem a estabilização local, com a especificação da taxa decaimento, de uma classe de sistemas não lineares contínuos no tempo, incertos e com saturação no atuador, utilizando o controle chaveado. Os projetos dos controladores são realizados com base no modelo fuzzy T-S que representa exatamente o sistema não linear e os procedimentos de projeto fornecem uma região na qual as condições iniciais devam estar, tal que, o sistema não linear seja exatamente descrito pelo modelo fuzzy T-S incerto durante toda a trajetória de estado do sistema e ainda que esta trajetória permaneça dentro de uma região de operação previamente especificada. Em geral, o controle chaveado não possui restrição na frequência de chaveamento dos ganhos, o que pode levar ao chattering, que se manifesta pelo chaveamento em frequência infinitamente rápida dos ganhos de realimentação. Visando a eliminação do chattering no controle chaveado, propõe-se uma nova técnica de suavização do controle chaveado, o controle chaveado suave. Esta nova lei de controle pode ser utilizada nas mesmas condições do controle chaveado e é baseada no conceito do mínimo suave, definido neste trabalho. Além disso, são propostos procedimentos de projeto que consideram distúrbios para ambas as leis de controle chaveada e chaveada suave. Ademais, neste trabalho também se apresenta uma implementação da lei de controle chaveada em um sistema Ball Balancer fabricado pela Quanser.
The switched control can be efficiently used for controlling uncertain Takagi-Sugeno (T-S) fuzzy systems, which have uncertain membership functions and known local models. Because these fuzzy systems can exactly represent a class of uncertain nonlinear systems in a given operation region in the state space, it is interesting to use them to describe nonlinear systems, performing the controller design based on a T-S fuzzy model that exactly describes the nonlinear system. However, the perfect representation of the uncertain nonlinear system by the T-S fuzzy model as a convex combination is only valid in the operation region. Therefore, it is necessary to assure conditions such that the state of the system remains in that region. This work proposes conditions to ensure the local stabilization, with decay rate, of a class of uncertain continuoustime nonlinear systems with saturation on the actuator, using a switched control. The designs of the controllers are performed based on the T-S fuzzy model which exactly describes the nonlinear system and the design procedures provide a region in which the initial conditions must be such that the nonlinear system is exactly described by the uncertain T-S fuzzy model along the whole state trajectory of the system and this trajectory remains in a specified operation region. Usually, the switched control has no bound on the frequency of the feedback gains switching, and this can lead to chattering, which is manifested by infinitely fast frequency of the feedback gains switching. In order to avoid the chattering in the switched control, this work proposes a new technique to smooth the switched control, the smooth switched control. This new control law can be used under the same conditions as the switched control and it is based on the concept of smooth minimum, which is defined in this work. In addition, design procedures considering disturbances for both switched and smooth switched control laws are proposed. Furthermore, in this work it is also presented an implementation of the proposed switched control law in a Ball Balancer system manufactured by Quanser.
Tse, Wilfred See Foon. "Linear equivalents of nonlinear systems." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26652.
Повний текст джерелаScience, Faculty of
Mathematics, Department of
Graduate
Enqvist, Martin. "Linear Models of Nonlinear Systems." Doctoral thesis, Linköping : Linköpings universitet, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-5330.
Повний текст джерелаLutz, Collin C. "Switched Markov Jump Linear Systems: Analysis and Control Synthesis." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/50859.
Повний текст джерелаPh. D.
Samavat, Mohmoud. "Robust control of nonlinear systems." Thesis, University of Sheffield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327647.
Повний текст джерелаCarniato, Leonardo Ataide. "Robust H∞ switched static output feedback control design for linear switched systems subject to actuator saturation /." Ilha Solteira, 2019. http://hdl.handle.net/11449/183007.
Повний текст джерелаResumo: Este trabalho dedica-se ao estudo do problema de controle robusto envolvendo custo H∞ para sistemas lineares chaveados no tempo contínuo, sujeitos à saturação no atuador e com incertezas politópicas, considerando leis de chaveamento e controladores chaveados dependentes da saída da planta. Os métodos propostos oferecem novas condições baseadas em Desigualdades Matriciais Lineares (LMIs - do inglês, Linear Matrix Inequalities) para o projeto de controladores chaveados utilizando funções de Lyapunov dependentes de parâmetros. O método é baseado em um resultado recentemente introduzido na literatura para o projeto de controle H∞ de saída o qual evita igualdades matriciais lineares (LMEs - do inglês, Linear Matrix Equalities) e a necessidade de impor restrições nas matrizes de saída do sistema, isto é, as matrizes de saída do sistema podem ser de posto linha incompleto. Com o objetivo de estender estes resultados, a restrição de saturação no atuador é estudada. Análises teóricas e resultados de simulações mostram que os novos procedimentos são menos conservativos quando comparados a métodos publicados recentemente na literatura. No método proposto, as condições são uma classe particular de desigualdades matriciais bilineares (BMIs - do inglês, Bilinear Matrix Inequalities), as quais contêm alguns termos bilineares devido à multiplicação de matrizes por escalares. Estes termos estão relacionados à combinação convexa das matrizes de chaveamento bem como a outros parâmetros escalare... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: This thesis is devoted to the study of the robust H∞ control problem of continuous-time switched linear systems subject to actuator saturation with polytopic uncertainties, considering an output-dependent switching law and a switched static output feedback controller. The proposed method offers new sufficient conditions based on linear matrix inequalities (LMIs) for designing the switched controllers using parameter-dependent Lyapunov functions. The method is based on a static output feedback H∞ control design recently presented in the literature that avoids linear matrices equalities (LMEs) and the need to impose any constraints on output system matrices, that is, the output matrices of the system are allowed to be of non-full row rank. In order to extend those results, the actuator saturation constraint is also studied. Theoretical analyses and simulation results show that these new procedures are less conservative than recent methods available in the literature. The conditions of the proposed methods are a particular class of Bilinear Matrix Inequalities (BMIs), which contain some bilinear terms as the product of a matrix and a scalar, related to a suitable convex combination and scalars parameters to provide extra free dimensions in the solution space. The hybrid algorithm Differential Evolution-Linear Matrix Inequality (DE-LMI), is proposed for obtaining feasible solutions of this particular NP-hard problem. Examples show that the proposed methodologies reduce the design ... (Complete abstract click electronic access below)
Doutor
Duan, Chang. "Analysis and Control of Switched Linear Systems Using Different Switching Strategies." Thesis, North Carolina State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3586263.
Повний текст джерелаAs a subclass of hybrid systems that exhibiting both continuous and discrete dynamics, switched systems typically consists of a family of differential/difference equations and a rule that orchestrates the switching among them. Switched systems provide a useful mechanism to model complex dynamics that are subject to abrupt parameter variations and sudden changes of system configurations. Moreover, as an additional degree of freedom besides control laws, switching strategies can be utilized to improve system performance as seen in many engineering systems such as electronics, communication network, power systems, automobile and traffic control. Nevertheless, analysis and control design of switched systems are difficult and pose significant challenges for control researchers and engineers. This dissertation is dedicated to analysis and control design of switched linear systems using different switching strategies.
We first study the analysis and control problem of switched linear systems subject to actuator saturation under controlled switching. With a state-dependent switching strategy and linear differential inclusion (LDI) description of the saturated switched systems, both stabilization and output feedback control design problem are addressed. Initially, we proposed an approach based on polytopic differential inclusion (PDI) description of the saturated system. We then found two major drawbacks of this approach: 1) Computational cost grows drastically when the number of control inputs increases. 2) A conservative set mapping results in conservativeness in the synthesis conditions. Thus we proposed another approach based norm-bounded differential inclusion (NDI) characterization of the saturated system that performs better than the previous approach in these two aspects mentioned above.
We then investigate the inherent chattering behavior of the well-known state-dependent minimum switching strategy since chattering is undesirable in practice. To mitigate chattering, we developed a relaxed min-switching strategy based on the idea that switching is not forced whenever a different subsystem obtains the minimum of the Lyapunov function but held until the minimum of the Lyapunov function falls below the Lyapunov function of the active subsystem by certain margin. Based on this idea, a tunable parameter, which is related to how large the margin will be, is introduced into the switching rule. Consequently, stability analysis and control synthesis conditions are derived in terms of modified Lyapunov-Metzler inequalities.
The above mentioned relaxed min-switching strategy can effectively reduce the frequency of the switching. However, as a state-dependent switching strategy, it cannot guarantee how slow the switching can be in terms of the activation time of each subsystem. This motivates us to consider time-driven switching strategies. The so-called ”dwell-time” and ”average dwell-time” based switching strategies are the most popular time-driven switching strategies. Nevertheless, they are restricted to the class of switched systems with some or all stable subsystems. In view of this, a novel mixed state-dependent and time-driven switching strategy is developed for switched systems with all unstable subsystems. It guarantees the stability of the switched system with a sufficiently small dwell time by enforcing a decrement of the Lyapunov function at each switch. Moreover, it provides a more general framework of analyzing switched linear systems as it contains the min-switching and the relaxed min-switching as special cases when dwell-time is not concerned. When dwell-time is concerned, it eliminates the chattering behavior commonly observed in min-switching based designs.
Lee, Byeong-Seok. "Linear Switched Reluctance Machine Drives with Electromagnetic Levitation and Guidance Systems." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/29751.
Повний текст джерелаPh. D.
Huang, Jungang. "Spontaneous optical fractals in linear & nonlinear systems." Thesis, University of Salford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491053.
Повний текст джерелаWalker, Jimmie Dale 1977. "Analysis of primitive linear and nonlinear stochastic systems." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/86841.
Повний текст джерела"September 29, 2000."
Includes bibliographical references (p. 91-92).
by Jimmie Dale Walker, III.
M.Eng.
Toenger, Shanti. "Linear and Nonlinear Rogue Waves in Optical Systems." Thesis, Besançon, 2016. http://www.theses.fr/2016BESA2029/document.
Повний текст джерелаThis thesis describes the study of several different classes of linear and nonlinear effects in optics that generatelarge amplitude extreme events with properties analogous to the destructive “rogue waves” on the surface of theocean. The thesis begins with a brief overview of the analogous physics of wave localisation in hydrodynamicand optical systems, where we describe linear and nonlinear rogue wave generating mechanisms in bothcases. We then present numerical and experimental results for rogue wave generation in a linear opticalsystem consisting of free space propagation of a spatial optical field with random phase. Computed statisticsbetween experiment and modelling are in good agreement, and we interpret the results obtained in termsof the properties of localised optical caustics. We then consider rogue waves in the nonlinear system ofmodulation instability described by the Nonlinear Schrodinger Equation (NLSE), and a detailed numericalstudy is presented comparing the spatio-temporal characteristics of localised structures seen from numericalsimulations with different known analytic solutions to the NLSE. Two experimental studies of modulationinstability are then reported. In the first, we present experimental results studying the properties of modulationinstability using a time-lens magnifier system; in the second, we report experimental results studying thefrequency-domain properties of modulation instability using real-time spectral measurements. The latter studyexamines the effect of a weak seed field on spectral bandwidth and stability. All experimental results arecompared with the NLSE simulations and discussed in terms of the qualitative properties of modulationinstability, in order to gain new insights into the complex dynamics associated with nonlinear pulse propagation.In all of these studies, different statistical properties are analised in relation to the emergence of rogue waves
Anand, Mantrala. "Transition through resonance in linear and nonlinear systems /." Online version of thesis, 1991. http://hdl.handle.net/1850/10995.
Повний текст джерелаTucher, Christopher A. "Steady-state oscillations of linear and nonlinear systems /." Online version of thesis, 1992. http://hdl.handle.net/1850/10990.
Повний текст джерелаSchweickhardt, Tobias. "Nonlinearity assessment and linear control of nonlinear systems." [S.l. : s.n.], 2006. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-29806.
Повний текст джерелаCardwell, E. A. "Stability of linear and nonlinear delay-differential systems." Thesis, University of Bath, 1995. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295447.
Повний текст джерелаKloiber, Tobias [Verfasser]. "Constructive Passivity-Based Control of Smooth and Switched Nonlinear Systems / Tobias Kloiber." Aachen : Shaker, 2015. http://d-nb.info/1070152137/34.
Повний текст джерелаOhlsson, Henrik, and Lennart Ljung. "Identification of switched linear regression models using sum-of-norms regularization." Linköpings universitet, Reglerteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-92612.
Повний текст джерелаFunding Agencies|Swedish foundation for strategic research in the center MOVIII||Swedish Research Council in the Linnaeus center CADICS||European Research Council|267381|Sweden-America Foundation||Swedish Science Foundation||
Wang, Ying-tsai 1955. "Frequency response of nonlinear pneumatic systems /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487266362339231.
Повний текст джерелаMazanti, Guilherme. "Stability and stabilization of linear switched systems in finite and infinite dimensions." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX045/document.
Повний текст джерелаMotivated by previous work on the stabilization of persistently excited systems, this thesis addresses stability and stabilization issues for linear switched systems in finite and infinite dimensions. After a general introduction presenting the main motivations and important results from the literature, we analyze four problems.The first system we study is a linear finite-dimensional random switched system. The time spend on each subsystem $i$ is chosen according to a probability law depending only on $i$, and the switches between subsystems are determined by a discrete Markov chain. We characterize the Lyapunov exponents by applying Oseledets' Multiplicative Ergodic Theorem to an associated discrete-time system, and provide an expression for the maximal Lyapunov exponent. These results are applied to a switched control system, showing that, under a controllability hypothesis, almost sure stabilization can be achieved with arbitrarily large decay rates, a situation in contrast to deterministic persistently excited systems.We next consider a system of $N$ transport equations with intermittent internal damping, linearly coupled by their boundary conditions through a matrix $M$, which can be seen as a system of PDEs on a star-shaped network. We prove that, if the activity of the intermittent damping terms is determined by persistently exciting signals, then, under suitable hypotheses on $M$ and on the rationality of the ratios between the lengths of the network edges, such system is exponentially stable, uniformly with respect to the persistently exciting signals. The proof of this result is based on an explicit representation formula for the solutions of the system, which allows one to efficiently track down the effects of the intermittent damping.The following topic we address is the asymptotic behavior of non-autonomous difference equations. We obtain an explicit representation formula for their solutions in terms of their initial conditions and some time-dependent matrix coefficients, which generalizes the one for the system of $N$ transport equations. The asymptotic behavior of solutions is characterized in terms of the matrix coefficients. In the case of difference equations with arbitrary switching, we obtain a stability result which generalizes Hale--Silkowski criterion for autonomous systems. Using classical transformations of hyperbolic PDEs into difference equations, we apply our results to transport and wave propagation on networks.Finally, we generalize the previous representation formula to a controlled difference equation, whose controllability is then analyzed. Relative controllability is characterized in terms of an algebraic property on the matrix coefficients from the explicit formula, generalizing Kalman criterion. We also compare the relative controllability for different delays in terms of their rational dependence structure, and provide a bound on the minimal controllability time. Exact and approximate controllability for systems with commensurable delays are characterized and proved to be equivalent. We also describe exact and approximate controllability for two-dimensional systems with two delays not necessarily commensurable
Ait, Ladel Ayyoub. "Commande tolérante aux défauts des systèmes à multimodèles : application à des systèmes à multi-source d'énergie." Electronic Thesis or Diss., Aix-Marseille, 2022. http://theses.univ-amu.fr.lama.univ-amu.fr/220330_AITLADEL_882kmyqu655hkbca383zrkcz402ihwf_TH.pdf.
Повний текст джерелаThis thesis deals with the fault detection/estimation and fault-tolerant control challenges through integrated design. The aim is to design control strategies able to maintain robust and acceptable performance even in the presence of faults. The considered systems are dynamic in nature and are multi-model. The approaches proposed in this thesis consist in formalizing the integrated design of the detection/estimation and fault-tolerant control units in the form of linear matrix inequalities to overcome the difficulty posed by the observer/controller coupling. These approaches provide the ability to consider the different interactions between the system, the detection/estimation unit, and the control unit. Therefore, ensuring a global stability analysis of the closed-loop system and robust performances in terms of detection/estimation, control, and fault compensation. The thesis is mainly composed of three parts. In the first part, results on the control in the presence of sensor or actuator faults are established for switched linear systems. In the second part, extensions to switched nonlinear systems with sensor and actuator faults are proposed. Finally, the third part consists of a complete study of a renewable energy system. It is a multi-source/multi-load system designed to meet multiple demands and is subject to the intermittency of renewable energies
Kartal, Elcin. "Metamodeling Complex Systems Using Linear And Nonlinear Regression Methods." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12608930/index.pdf.
Повний текст джерелаParuchuri, Sai Tej. "Modeling and Estimation of Linear and Nonlinear Piezoelectric Systems." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/100484.
Повний текст джерелаDoctor of Philosophy
Piezoelectric materials are materials that generate an electric charge when mechanical stress is applied, and vice versa, in a lossless transformation. Engineers have used piezoelectric materials for a variety of applications, including vibration control and energy harvesting. This dissertation introduces (1) novel methods for vibration attenuation using an array of piezoelectric oscillators, and (2) methods to model and estimate the nonlinear behavior exhibited by piezoelectric materials at very high mechanical forces or electric charges. Arrays of piezoelectric oscillators attached to a host structure are termed piezoelectric subordinate oscillator arrays (PSOAs). With the careful design of PSOAs, we show that we can reduce the vibration of the host structure. This dissertation analyzes methodologies for designing PSOAs and illustrates their vibration attenuation capabilities numerically and experimentally. The numerical and experimental studies also illustrate the robustness of PSOAs. In the second part of this dissertation, we analyze reproducing kernel Hilbert space embedding methods for adaptive estimation of nonlinearities in piezoelectric systems. Kernel methods are extensively used in machine learning, and control theorists have studied adaptive estimation of functions in finite-dimensional spaces. In this work, we adapt kernel methods for adaptive estimation of functions in infinite-dimensional spaces that appear while modeling piezoelectric systems. We derive theorems that ensure convergence of function estimates to the actual function and develop algorithms for careful selection of the kernel basis functions.
Fuster, Criado Laura. "Linear and nonlinear room compensation of audio rendering systems." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/59459.
Повний текст джерела[ES] Los sistemas de audio actuales están diseñados con la idea de crear escenarios reales e inmersivos que permitan al usuario experimentar determinadas sensaciones acústicas que no dependan de la sala o situación donde se esté percibiendo el sonido. Sin embargo, los dispositivos acústicos y los sistemas multicanal funcionando dentro de salas, pueden perjudicar el efecto global sonoro y de esta forma, el sonido espacial 3D. Para poder preservar las características espaciales sonoras de los sistemas de reproducción multicanal, en esta tesis se presentan los esquemas de filtrado adaptativo para compensar dichos efectos electroacústicos y conseguir la sensación inmersiva del sistema sonoro deseado. El filtrado adaptativo ofrece una solución al problema de salas que es interesante por dos motivos. Por un lado, resuelve de forma iterativa el problema de inversión de salas, que puede llegar a ser computacionalmente costoso para los métodos de inversión directos existentes. Por otro lado, el uso de filtros adaptativos permite seguir las variaciones cambiantes de los efectos de la sala de escucha. A este respecto, los filtros de ecualización adaptativa (AE) intentan cancelar los ecos introducidos por la sala de escucha. En esta tesis se considera este problema y se proponen esquemas lineales efectivos y robustos para resolver el problema de ecualización mediante filtros adaptativos. Para conseguirlo, se introducen diferentes esquemas de filtrado adaptativo para AE. Estos esquemas de filtrado se basan en tres estrategias ya usadas en la literatura: la combinación convexa de filtros, el sesgado de los coeficientes del filtro y el filtrado basado en bloques. Más especificamente y motivado por la naturaleza dispersiva de las respuestas al impulso acústicas y de sus correspondientes filtros inversos óptimos, se presentan diversos algoritmos adaptativos de ecualización específicos. Además, ya que los sistemas de audio inmersivos requieren usar normalmente múltiples trasductores, se debe considerar también el problema de ecualización multicanal adaptativa cuando se diseñan nuevas estrategias de filtrado adaptativo para sistemas monocanal, ya que éstas deben ser fácilmente extrapolables al caso multicanal. Por otro lado, cuando se utilizan dispositivos acústicos, se debe considerar la existencia de no linearidades en el sistema elactroacústico, para poder ecualizarlo correctamente. Por este motivo, se propone un nuevo modelo no lineal de filtrado-x que compense a la vez la reverberación introducida por la sala y la distorsión no lineal con memoria provocada por el amplificador y el altavoz. Por último, es importante validar los algoritmos propuestos mediante implementaciones en tiempo real, para asegurarnos que pueden realizarse. Para ello, se presentan algunos resultados experimentales iniciales que muestran la idoneidad de la ecualización adaptativa en problemas de compensación de salas.
[CAT] Els sistemes d'àudio actuals es dissenyen amb l'objectiu de crear ambients reals i immersius que permeten a l'usuari experimentar una sensació acústica particular que no depèn de la sala on està percebent el so. No obstant això, els dispositius acústics i els sistemes de renderització multicanal treballant dins d'una sala poden arribar a modificar l'efecte global de l'àudio i per tant, l'efecte 3D del so a l'espai. Amb l'objectiu de conservar les característiques espacials del so obtingut amb tècniques de renderització multicanal, aquesta tesi doctoral presenta esquemes de filtrat adaptatiu per a compensar aquests efectes electroacústics i aconseguir una sensació immersiva del sistema acústic desitjat. El filtrat adaptatiu presenta una solució al problema d'equalització de sales que es interessant baix dos punts de vista. Per una banda, el filtrat adaptatiu resol de forma iterativa el problema inversió de sales, que pot arribar a ser molt complexe computacionalment quan s'utilitzen mètodes directes. Per altra banda, l'ús de filtres adaptatius permet fer un seguiment de les condicions canviants de la sala amb el temps. Més concretament, els filtres d'equalització adaptatius (EA) intenten cancel·lar els ecos produïts per la sala. A aquesta tesi, considerem aquest problema i proposem esquemes lineals efectius i robustos per a resoldre aquest problema d'equalització mitjançant filtres adaptatius. Per aconseguir-ho, diferent esquemes de filtrat adaptatiu es presenten dins del context del problema d'EA. Aquests esquemes de filtrat es basen en tres estratègies ja presentades a l'estat de l'art: la combinació convexa de filtres, el sesgat dels pesos del filtre i el filtrat basat en blocs. Més concretament, i motivat per la naturalesa dispersa de la resposta a l'impuls acústica i el corresponent filtre òptim invers, presentem diferents algorismes d'equalització adaptativa. A més a més, com que els sistemes d'àudio immersiu normalment requereixen l'ús de múltiples transductors, cal considerar també el problema d'equalització adaptativa multicanal quan es presenten noves solucions de canal simple, ja que aquestes s'han de poder estendre fàcilment al cas multicanal. Un altre aspecte a considerar quan es treballa amb dispositius d'àudio és el de les no linealitats del sistema a l'hora d'equalitzar correctament el sistema electroacústic. Amb aquest objectiu, a aquesta tesi es proposa una nova tècnica basada en filtrat-x no lineal, per a compensar tant la reverberació de la sala com la distorsió no lineal amb memòria introduïda per l'amplificador i els altaveus. Per últim, és important validar la implementació en temps real dels algorismes proposats. Amb aquest objectiu, alguns resultats inicials demostren la idoneïtat de l'equalització adaptativa en problemes de compensació de sales.
Fuster Criado, L. (2015). Linear and nonlinear room compensation of audio rendering systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59459
TESIS
Meair, Jonathan Isaac. "Aspects of Linear and Nonlinear Transport in Mesoscopic Systems." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/301737.
Повний текст джерелаCocetti, Matteo. "Nonlinear and Hybrid Feedbacks with Continuous-Time Linear Systems." Thesis, Toulouse, INSA, 2019. http://www.theses.fr/2019ISAT0014/document.
Повний текст джерелаIn this thesis we study linear time-invariant systems feedback interconnected with three specific nonlinear blocks; a play/stop operator, a switching-reset mechanism, and an adaptive dead-zone. This setup resembles the Lure problem studied in the absolute stability framework, but the types of nonlinearities considered here do not satisfy (in general) a sector condition. These nonlinear blocks give rise to a whole range of interesting phenomena, such as compact sets of equilibria, hybrid omega-limit sets, and state constraints. Throughout the thesis, we use the hybrid systems formalism to describe these phenomena and to analyze these loops. We obtain sharp stability conditions that can be formulated as linear matrix inequalities, thus verifiable with numerically efficient solvers. Finally, we apply the theoretical findings to two automotive applications
Cocetti, Matteo. "Nonlinear and Hybrid Feedbacks with Continuous-Time Linear Systems." Doctoral thesis, Università degli studi di Trento, 2019. https://hdl.handle.net/11572/368312.
Повний текст джерелаCocetti, Matteo. "Nonlinear and Hybrid Feedbacks with Continuous-Time Linear Systems." Doctoral thesis, University of Trento, 2019. http://eprints-phd.biblio.unitn.it/3675/1/phdthesis-matteococetti.pdf.
Повний текст джерелаFeng, Ming. "Local modelling and control of nonlinear systems." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326788.
Повний текст джерелаBenouarets, Mourad. "Some design methods for linear and nonlinear controllers." Thesis, University of Sussex, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333454.
Повний текст джерелаSantarelli, Keith R. (Keith Robert) 1977. "On the synthesis of switched output feedback controllers for linear, time-invariant systems." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/38690.
Повний текст джерелаIncludes bibliographical references (p. 189-193).
The theory of switching systems has seen many advances in the past decade. Its beginnings were founded primarily due to the physical limitations in devices to implement control such as relays, but today there exists a strong interest in the development of switching systems where switching is introduced as a means of increasing performance. With the newer set of problems that arise from this viewpoint comes the need for many new tools for analysis and design. Analysis tools which include, for instance, the celebrated work on multiple Lyapunov functions are extensive. Tools for the design of switched systems also exist, but, in many cases, the method of designing stabilizing switching laws is often a separate process from the method which is used to determine the set of vector fields between which switching takes place. For instance, one typical method of designing switching controllers for linear, time-invariant (LTI) systems is to first design a set of stabilizing LTI controllers using standard LTI methods, and then design a switching law to increase performance. While such design algorithms can lead to increases in performance, they often impose restrictions that do not allow the designer to take full advantage of the switching architecture being considered.
(cont.) For instance, if one switches between controllers that are individually stabilizing (without any switching), then, effectively, one is forced to switch only between stable systems and, hence, cannot take advantage of the potential benefits of switching between unstable systems in a stable way. It is, therefore, natural to wonder whether design algorithms can be developed which simultaneously design both the set of controllers to be switched and a stabilizing switching law. The work investigated here attempts to take a small step in the above direction. We consider a simple switching architecture that implements switched proportional gain control for second order LTI systems. Examination of this particular structure is motivated by its mathematical simplicity for ease of analysis (and, hence, as a means of gaining insight into the problem-at-large), but, as we will see, the design techniques investigated here can be extended to a larger class of (higher order, potentially non-linear and/or time-varying) systems using standard tools from robust control. The overall problem we investigate is the ability to create algorithms to simultaneously determine a set of switching gains and an associated switching law for a particular plant and performance objective.
(cont.) After determining a set of necessary and sufficient conditions for a given second order plant to be stabilizable via the given switching architecture, we synthesize an algorithm for constructing controllers for which the corresponding closed-loop system dynamics are finite L, gain stable. Also, in an effort to demonstrate that the the given structure can, in fact. he used to increase performance. we consider a step-tracking design problem for a class of plants, where we use overshoot and settling time of the output step response to measure performance. We compare the results obtained using our switching architecture to the performance that can be obtained via two other LTI controller architectures to illustrate some of the performance benefits.
by Keith Robert Santarelli.
Ph.D.
Reichelt, Matthias. "Linear and nonlinear optical excitations in spatially-inhomogeneous semiconductor systems." [S.l. : s.n.], 2005. http://archiv.ub.uni-marburg.de/diss/z2005/0123/.
Повний текст джерелаFarag, Emile. "Modeling of nonlinear systems using linear time-varying ARMAX models." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0017/MQ54107.pdf.
Повний текст джерелаWei, Xiaojun. "Active vibration control in linear time-invariant and nonlinear systems." Thesis, University of Liverpool, 2015. http://livrepository.liverpool.ac.uk/2012679/.
Повний текст джерелаAhmadi, Amir Ali. "Non-monotonic Lyapunov functions for stability of nonlinear and switched systems : theory and computation." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/44206.
Повний текст джерелаThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 87-90).
Lyapunov's direct method, which is based on the existence of a scalar function of the state that decreases monotonically along trajectories, still serves as the primary tool for establishing stability of nonlinear systems. Since the main challenge in stability analysis based on Lyapunov theory is always to nd a suitable Lyapunov function, weakening the requirements of the Lyapunov function is of great interest. In this thesis, we relax the monotonicity requirement of Lyapunov's theorem to enlarge the class of functions that can provide certicates of stability. Both the discrete time case and the continuous time case are covered. Throughout the thesis, special attention is given to techniques from convex optimization that allow for computationally tractable ways of searching for Lyapunov functions. Our theoretical contributions are therefore amenable to convex programming formulations. In the discrete time case, we propose two new sucient conditions for global asymptotic stability that allow the Lyapunov functions to increase locally, but guarantee an average decrease every few steps. Our first condition is nonconvex, but allows an intuitive interpretation. The second condition, which includes the first one as a special case, is convex and can be cast as a semidenite program. We show that when non-monotonic Lyapunov functions exist, one can construct a more complicated function that decreases monotonically. We demonstrate the strength of our methodology over standard Lyapunov theory through examples from three different classes of dynamical systems. First, we consider polynomial dynamics where we utilize techniques from sum-of-squares programming. Second, analysis of piecewise ane systems is performed. Here, connections to the method of piecewise quadratic Lyapunov functions are made.
(cont.) Finally, we examine systems with arbitrary switching between a finite set of matrices. It will be shown that tighter bounds on the joint spectral radius can be obtained using our technique. In continuous time, we present conditions invoking higher derivatives of Lyapunov functions that allow the Lyapunov function to increase but bound the rate at which the increase can happen. Here, we build on previous work by Butz that provides a nonconvex sucient condition for asymptotic stability using the first three derivatives of Lyapunov functions. We give a convex condition for asymptotic stability that includes the condition by Butz as a special case. Once again, we draw the connection to standard Lyapunov functions. An example of a polynomial vector field is given to show the potential advantages of using higher order derivatives over standard Lyapunov theory. We also discuss a theorem by Yorke that imposes minor conditions on the first and second derivatives to reject existence of periodic orbits, limit cycles, or chaotic attractors. We give some simple convex conditions that imply the requirement by Yorke and we compare them with those given in another earlier work. Before presenting our main contributions, we review some aspects of convex programming with more emphasis on semidenite programming. We explain in detail how the method of sum of squares decomposition can be used to efficiently search for polynomial Lyapunov functions.
by Amir Ali Ahmadi.
S.M.
VITAIOLI, Giorgio. "Control of nonlinear systems with limited information." Doctoral thesis, Università Politecnica delle Marche, 2011. http://hdl.handle.net/11566/242009.
Повний текст джерелаIn traditional control, system’s sensory information is assumed to be available for control purposes in real time and continuously, for any t, although, in practice, these conditions are not usually satisfied. Actually, in many situations, delays may be so small, compared with the time constants of the systems at issue, that they can be safely ignored and sampling frequencies may be so high that continuous signals can be accurately reconstructed from sampled data. However, when there are limitations on the information’s transmission rate and on the band occupancy, like in networked systems, delays cannot be neglected and the information flow cannot be assumed to be continuous. This dissertation investigates the stability properties of a controlled plant in which signals can be transferred from the controller’s level to the plant’s level continuously, while information can be fed back from the plant’s level to the controller’s level only at sampling times. As frequently happens in application, one cannot assume a complete knowledge of the plant’s dynamics, but only that a model of it is available for control purposes. In such situations, sampled information coming from the plant and information coming from the model can be used to synthesize the control signal in a suitable model-based feedback control scheme. The results one would like to obtain concern the maximum length of the sampling interval for which the stabilizing performances of a given control scheme can be assured. The problem was previously considered, under analogous assumptions, by L.Montestruque and P.J.Antsaklis, who developed the Model-Based control scheme for Networked Systems (Model-Based Networked Control System or MB-NCS) for linear dynamics and for particular nonlinear dynamics with vanishing perturbation. In MB-NCS a model is used to simulate the plant evolution between transmission instants when no information about the plant is available. The aim of this dissertation is to present the MBNCS approach and to extend it to more general type of nonlinear plants and problems. The stability analysis of particular and general nonlinear MB-NC systems is carried out, for various types of perturbations and in the presence of disturbances. Under suitable hypotheses on the plant’s dynamics, the perturbation entity, the control performances and the length of the sampling period, sufficient conditions for semiglobal uniform boundedness or semiglobal asymptotical stability have been found.
Loxton, Ryan Christopher. "Optimal control problems involving constrained, switched, and delay systems." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/1479.
Повний текст джерелаXi, Zhiyu Electrical Engineering & Telecommunications Faculty of Engineering UNSW. "Identification and control of nonlinear laboratory processes." Awarded by:University of New South Wales. Electrical Engineering & Telecommunications, 2007. http://handle.unsw.edu.au/1959.4/40461.
Повний текст джерелаPETTINARI, SILVIA. "Fault Diagnosis Techniques for Linear Sampled Data Systems and a Class of Nonlinear Systems." Doctoral thesis, Università degli Studi di Camerino, 2012. http://hdl.handle.net/11581/401797.
Повний текст джерелаTan, Kay Chen. "Evolutionary methods for modelling and control of linear and nonlinear systems." Thesis, University of Glasgow, 1997. http://theses.gla.ac.uk/8473/.
Повний текст джерелаAlqasas, Neveen. "Membrane Characterization for Linear and Nonlinear Systems: Upstream and Downstream Methods." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34979.
Повний текст джерелаFranz, David, and University of Lethbridge Faculty of Arts and Science. "Turing patterns in linear chemical reaction systems with nonlinear cross diffusion." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2007, 2007. http://hdl.handle.net/10133/659.
Повний текст джерелаvi, 55 leaves : ill. ; 29 cm.
Phadnis, Akash. "Uncertainty quantification and prediction for non-autonomous linear and nonlinear systems." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/85476.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (pages 189-197).
The science of uncertainty quantification has gained a lot of attention over recent years. This is because models of real processes always contain some elements of uncertainty, and also because real systems can be better described using stochastic components. Stochastic models can therefore be utilized to provide a most informative prediction of possible future states of the system. In light of the multiple scales, nonlinearities and uncertainties in ocean dynamics, stochastic models can be most useful to describe ocean systems. Uncertainty quantification schemes developed in recent years include order reduction methods (e.g. proper orthogonal decomposition (POD)), error subspace statistical estimation (ESSE), polynomial chaos (PC) schemes and dynamically orthogonal (DO) field equations. In this thesis, we focus our attention on DO and various PC schemes for quantifying and predicting uncertainty in systems with external stochastic forcing. We develop and implement these schemes in a generic stochastic solver for a class of non-autonomous linear and nonlinear dynamical systems. This class of systems encapsulates most systems encountered in classic nonlinear dynamics and ocean modeling, including flows modeled by Navier-Stokes equations. We first study systems with uncertainty in input parameters (e.g. stochastic decay models and Kraichnan-Orszag system) and then with external stochastic forcing (autonomous and non-autonomous self-engineered nonlinear systems). For time-integration of system dynamics, stochastic numerical schemes of varied order are employed and compared. Using our generic stochastic solver, the Monte Carlo, DO and polynomial chaos schemes are inter-compared in terms of accuracy of solution and computational cost. To allow accurate time-integration of uncertainty due to external stochastic forcing, we also derive two novel PC schemes, namely, the reduced space KLgPC scheme and the modified TDgPC (MTDgPC) scheme. We utilize a set of numerical examples to show that the two new PC schemes and the DO scheme can integrate both additive and multiplicative stochastic forcing over significant time intervals. For the final example, we consider shallow water ocean surface waves and the modeling of these waves by deterministic dynamics and stochastic forcing components. Specifically, we time-integrate the Korteweg-de Vries (KdV) equation with external stochastic forcing, comparing the performance of the DO and Monte Carlo schemes. We find that the DO scheme is computationally efficient to integrate uncertainty in such systems with external stochastic forcing.
by Akash Phadnis.
S.M.
Mason, Richard. "A chordal sparsity approach to scalable linear and nonlinear systems analysis." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:c4a978aa-185e-4029-a887-6aa2ab9efb37.
Повний текст джерелаTien, Meng-Hsuan. "Analyzing and Exploiting the Dynamics of Complex Piecewise-Linear Nonlinear Systems." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1586039513469825.
Повний текст джерелаTan, Hendra. "Linear and nonlinear rheological properties of diblock and triblock copolymer systems." 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/145340.
Повний текст джерела