In this thesis, a multiple hypotheses tracking (MHT) algorithm is developed to successfully track multiple ballistic missiles within the boost phase. The success of previous work on the MHT algorithm and its application in other scientific fields enables this study to realize an efficient form of the algorithm and examine its feasibility in tracking multiple crossing ballistic missiles even though various accelerations due to staging are present. A framework is developed for the MHT, which includes a linear assignment problem approach used to search the measurement-to-contact association matrix for the set of exact N-best feasible hypotheses. To test the new MHT, an event in which multiple ballistic missiles have been launched and threaten the North American continent is considered. To aid in the interception and destruction of the threat far from their intended targets, the research focuses on the boost-phase portion of the missile flight. The near-simultaneous attacks are detected by a network of radar sensors positioned near the missile launch sites. Each sensor provides position reports or track files for the MHT routine to process. To quantify the performance of the algorithm, data from the National Air and Space Intelligence Center's IMPULSE ICBM model is used and demonstrates the feasibility of this approach. This is especially significant to the U.S. Missile Defense Agency since the IMPULSE model represents the cognizant analyst's accurate representation of the ballistic threats in a realistic environment. The results show that this new algorithm works exceptionally well in a realistic environment where complex interactions of missile staging, non-linear thrust profiles and sensor noise can significantly degrade the track algorithm performance especially in multiple target scenarios.

Orientador: José Manoel Balthazar / Banca: Angelo Marcelo Tusset / Banca: Bento Rodrigues de Pontes Junior / Resumo: Neste trabalho é realizada a análise do comportamento dinâmico não linear, caótico e controle, de um sistema macro eletromecânico e um sistema micro eletromecânico, e esta dividida em duas partes: A primeira parte desta dissertação trata - se de um sistema eletromecânico de 2º ordem com um único grau de liberdade em escala macro. Tal sistema é constituído de um oscilador mecânico composto de massa, mola não linear e amortecedor acolplado a um circuito elétrico, este composto uma resistência em série com um atuador capacitivo e um magnésio variável. O objetivo desta análise é estudar o comportamento dinâmico do modelo eletromecânico em estado de equilíbrio, e verificar como as simplificaçõs das não linearidades podem alterar a resposta do sistema. São aplicadas dua técnicas de controle ativo o controle linear feedback e o controle utilizado a equação de Riccati dependente do estado, como ferramenta para obter as oscilações em uma órbita periódica desejada, e com a finalidade de realizar uma comparação entre a eficiência destes dois métodos, para este sistema. Na segunda parte é analisado o comportamento dinâmico de um sistema micro "MEMS", representado por um micro-acelerômetro moderado por uma equação diferencial não-linear de segunda ordem. Este sistema considera duas placas fixas e uma placa móvel entre elas, a qual é aplicada uma tensão V (t), tais placas têm as funções de fornecer eletrodos para formar um capacitor e armazenar energia elétrica, e de fornecer elasticidade ou rigidez mecânica. Os resultados são obtidos através de simulações numéricas, sendo possível observar que para uma determinada faixa de parâmetros utilizados o sistema apresenta um comportamento indesejável. Através do uso da técnica do controle ótimo foi possível levar o sistema a uma orbita periódica desejada / Abstract: This work presented analysis of the dynamic behavior of nonlinear and chaotic control, of electromechanical systems in macro and micro scales, and is divided into two parts. The first part of this work is an electromechanical system in macro scale of second order with of a single degree of freedom. This system consists of mechanical oscillator consisting of mass, spring nonlinear and damper, coupled to an electric circuit, this compound a resistence in series with a capacitive actuator and a magnetic variable. The purpose of this analysis is to study the dynamic behavior of electromechanical model in equilibrium, and see how the simplifications of nonlinearities can change the system response. Two techniques are applied to active control, linear feedback control, and control using the Riccati equation sate-dependent, as a tool for the oscillations in a disired periodic orbit, and with the purpose to make a comparison between the effectiveness of two methods for this system. In the second part we analyze the dynamic behavior of a micro electromechanical system MEMS, represented by a micro-accelerometer is modeled by a nonlinear differential equation of second order. This system takes two fixed plates and a movable plate between them, which is applied a voltage V (t), such boards have the function of providing electrodes to form a capacitor or store electrical energy, and providing mechanical stiffness or elasticity. Results are obtained through numerical simulations. As can be seen that for a certain range of parameters the sytem presents an undesirable behavior. Through the using the technique of optimal control could case the sysstem to a desired periodic orbit. For the system with dimensionless parameters one can observe a chaotic behavior. As in general it is not possible to obtain exact analytical solutions to equations, sought an approximate solution obtained by the method of perturbation, the (Method of Multiple Scales) / Mestre

In this work, we investigate input-to-state stability (ISS) and other related stability properties for control systems with time-delays. To overcome the complexity caused by the presence of the delays, we adopt a Razumikhin approach. The underlying idea of this approach is to treat the delayed variables as system uncertainties. The advantage of this approach is that one works in the more familiar territory of stability analysis for delay-free systems in the context of ISS instead of carrying out stability analysis on systems of functional differential equations. Our first step is to provide criteria on ISS and input-to-input stability properties based on the Razumikhin approach. We then turn our attention to large-scale interconnected systems. It has been well recognized that the small-gain theory is a powerful tool for stability analysis of interconnected systems. Using the Razumikhin approach, we develop small-gain theorems for interconnected systems consisting of two or more subs ystems with time-delays present either in the interconnection channels or within the subsystems themselves. As an interesting application, we apply our results to an existing model for hematopoesis, a blood cell production process,and improve the previous results derived by linear methods. Another important stability notion in the framework of ISS is the integral ISS (iISS) property. This is a weaker property than ISS, so it supplies to a larger class of systems. As in the case of ISS, we provide Razumikhin criteria on iISS for systems with delays. An example is presented to illustrate that though very useful in practice, the Razumikhin approach only provides sufficient conditions, not equivalent conditions. Finally, we address stability of time-varying systems with delays in the framework of ISS. / In particular, we consider Lyapunov-Razumikhin functions whose decay rates are affected by time-varying functions that can be zero or even negative on some sets of non-zero measure. Our motivation is that it is often less demanding to find or construct such a Lyapunov function than one with a uniform decay rate. We also extend our small-gain theorems to the time-varying case by treating the time-varying system as an auxiliary time-invariant system. / Shanaz Tiwari. / Thesis (Ph.D.)--Florida Atlantic University, 2012. / Includes bibliography and index. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.

As redes de distribuição de sinais de tempo - ou redes de sincronismo - têm a tarefa de distribuir os sinais de fase e freqüência ao longo de relógios geograficamente dispersos. Este tipo de rede é parte integrante de inúmeras aplicações e sistemas em Engenharia, tais como sistemas de comunicação e transmissão de dados, navegação e rastreamento, sistemas de monitoração e controle de processos, etc. Devido ao baixo custo e facilidade de implementação, a topologia mestre-escravo tem sido predominante na implementação das redes. Recentemente, devido ao surgimento das redes sem fio - wireless - de conexões dinâmicas, e ao aumento da freqüência de operação dos circuitos integrados, topologias complexas, tais como as redes mutuamente conectadas e small world têm ganhado importância. Essencialmente cada nó da rede é composto por um PLL - Phase-Locked Loop - cuja função é sincronizar um oscilador local a um sinal de entrada. Devido ao seu comportamentamento não-linear, o PLL apresenta um jitter com o dobro da freqüência de livre curso dos osciladores, prejudicando o desempenho das redes. Dessa forma, este trabalho tem como objetivo o estudo analítico e por simulação das condições que garantam a existência de estados síncronos, e do comportamento do jitter de fase nas redes de sincronismo. São analisadas as topologias mestre-escravo e mutuamente conectada para o PLL analógico clássico. / Network synchronization deals with the problem of distributing time and fre- quency among spatially remote locations. This kind of network is a constituent element of countless aplications and systems in Engineering, such as communication and data transmission systems, navigation and position determination, monitoring and process control systems, etc. Due to its low cost and simplicity, the master-slave architec- ture has been widely used. In the last few years, with the growth of the dynamically connected wireless networks and the rising operational frequencies of the integrated cir- cuits, the study of the mutually connected and small world architectures are becoming relevant. Essentially, each node of a synchronization network is constituted by a PLL - Phase-Locked Loop - circuit that must automatically adjust the phase of a local oscillator to the phase of an incoming signal. Because of its nonlinear behavior the PLL presents a phase jitter with the double of the free running frequency of the oscillators, impairing the network performance. Thus, this work aims to study, both analytically and by simulation, the existence conditions of the synchronous states and the behavior of the double frequency jitter in the synchronization networks. Specifically the One Way Master Slave (OWMS) and Mutually Connected (MC) network architectures for classical analogical PLLs are analyzed.

L'utilisation des véhicules sous-marins (ROV, AUV, gliders) s'est considérablement accrue ces dernières décennies, aussi bien dans le domaine de l'offshore ou de l'océanographie, que pour des applications militaires. Dans cette thèse, nous abordons le problème particulier de la commande des véhicules sous-marins à faible inertie et fort rapport puissance/inertie. Ces derniers constituent des systèmes fortement non linéaires, dont la dynamique est susceptible de varier au cours du temps (charge embarquée, caractéristiques des propulseurs, variation de salinité...) et qui sont très sensibles aux perturbations environnementales (chocs, traction sur l'ombilical...). Afin d'assurer des performances de suivi de trajectoire satisfaisantes, il est nécessaire d'avoir recours à une commande adaptative qui compense les incertitudes ou les variations des paramètres du modèle dynamique, mais également qui rejette les perturbations, telles que les chocs. A cette fin, nous proposons dans ce manuscrit, l'étude théorique et la validation expérimentale de plusieurs lois de commande pour véhicules sous-marins. Nous analysons tout d'abord des approches classiques dans ce domaine (commande PID et commande par retour d'état non linéaire), puis nous les comparons avec deux autres architectures de commande. La première est la commande adaptative L1 non linéaire, introduite en 2010 notamment pour la commande des véhicules aériens, et implémentée pour la première fois sur un véhicule sous-marin. Le découplage entre adaptation et robustesse permet l'utilisation de très grands gains d'adaptation (et donc une convergence plus rapide des paramètres estimés, sans aucune connaissance a priori), sans pour autant dégrader la stabilité. La seconde méthode, que nous proposons et qui constitue l'apport principal de cette thèse, est une évolution de la commande L1, permettant d'en améliorer les performances lors du suivi d'une trajectoire variable. Nous présentons une analyse de stabilité de cette commande, ainsi que sa comparaison expérimentale avec les autres lois de commande (commande PID, commande adaptative par retour d'état non linéaire et commande adaptative L1 standard). Ces expérimentations ont été réalisées sur un mini-ROV et plusieurs scenarii ont été étudiés, permettant ainsi d'évaluer, pour chaque loi, sa robustesse et son aptitude à rejeter les perturbations. / Underwater vehicles have gained an increased interest in the last decades given the multiple tasks they can accomplish in various fields, ranging from scientific to industrial and military applications. In this thesis, we are particularly interested in the category of vehicles having a high power to weight ratio. Different challenges in autonomous control of such highly unstable systems arise from the inherent nonlinearities and the time varyingbehavior of their dynamics. These challenges can be increased by the low inertia of this class of vehicles combined with their powerful actuation. A self tuning controller is therefore required in order to avoid any performance degradation during a specific mission. The closed-loop system is expected to compensate for different kinds of disturbances or changes in the model parameters. To solve this problem, we propose in this work the design,analysis and experimental validation of different control schemes on an underwater vehicle. Classical methods are initially proposed, namely the PID controller and the nonlinear adaptive state feedback (NASF) one, followed by two more advanced schemes based on the recently developed L1 adaptive controller. This last method stands out among the other developed ones in its particular architecture where robustness and adaptation are decoupled. In this thesis, the original L1 adaptive controller has been designed and successfullyvalidated then an extended version of it is proposed in order to deal with the observed time lags occurring in presence of a varying reference trajectory. The stability of this latter controller is then analysed and real-time experimental results for different operating conditions are presented and discussed for each proposed controller, assessing their performance and robustness.

Systems with time delays have a broad range of applications not only in control systems but also in many other disciplines such as mathematical biology, financial economics, etc. The time delays cause more complex behaviours of the systems. It requires more sophisticated analysis due to the infinite dimensional structure of the space spaces. In this thesis we investigate stability properties associated with output functions of delay systems. Our primary target is the equivalent Lyapunov characterization of input-tooutput stability (ios). A main approach used in this work is the Lyapuno Krasovskii functional method. The Lyapunov characterization of the so called output-Lagrange stability is technically the backbone of this work, as it induces a Lyapunov description for all the other output stability properties, in particular for ios. In the study, we consider two types of output functions. The first type is defined in between Banach spaces, whereas the second type is defined between Euclidean spaces. The Lyapunov characterization for the first type of output maps provides equivalence between the stability properties and the existence of the Lyapunov-Krasovskii functionals. On the other hand, as a special case of the first type, the second type output renders flexible Lyapunov descriptions that are more efficient in applications. In the special case when the output variables represent the complete collection of the state variables, our Lyapunov work lead to Lyapunov characterizations of iss, complementing the current iss theory with some novel results. We also aim at understanding how output stability are affected by the initial data and the external signals. Since the output variables are in general not a full collection of the state variables, the overshoots and decay properties may be affected in different ways by the initial data of either the state variables or just only the output variables. Accordingly, there are different ways of defining notions on output stability, making them mathematically precisely. After presenting the definitions, we explore the connections of these notions. Understanding the relation among the notions is not only mathematically necessary, it also provides guidelines in system control and design. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

Esta tese tem por objetivo a obtenção de modelos que apresentem melhor desempenho quando utilizados em controladores preditivos baseados em modelo (Model-based Predictive Control, MPC). Ao longo dos últimos 25 anos diversos trabalhos propuseram métodos baseados na minimização de uma função de predição múltiplos passos à frente, que se caracteriza por ser uma função não linear. Estes métodos foram denominados MPC Relevent Identification (MRI). A maioria destes artigos propõe técnicas para a obtenção de modelos lineares. Ao longo dos últimos 5 anos, alguns métodos, também baseados na minimização da função de predição múltiplos passos à frente, foram propostos para a identificação de modelos não lineares. Estes trabalhos são baseados na minimização direta da função de custo não linear, para obter com estrutura NARMAX (Nonlinear Autoregressive Moving Average with exogenous inputs). Entretanto, estruturas simplificadas de controladores MPC não lineares podem ser obtidas utilizando modelos com estruturas de Wiener e de Hammerstein. Esta tese apresenta novos resultados teóricos que permitem a obtenção de algoritmos de identificação MRI para modelos com estrutura de Wiener e Hammerstein, sem a necessidade de minimizar a função de custo não linear. Além da demonstração dos resultados teóricos, novos algoritmos são propostos tendo a sua capacidade de predição, propriedades estatísticas e aplicação em controladores MPC não lineares avaliadas. / This thesis focuses on obtaining models that may produce a better performance of Model-based Predictive Controllers (MPC). Several papers published in the last 25 years have proposed methods based on the minimization of multi-step ahead prediction functions, which are inherently nonlinear. These methods have been called MPC Relevant Identification (MRI). Most of the papers focused on obtaining linear models. In the last 5 years, some methods have been proposed to obtain nonlinear models based on the minimization of the same cost function. These papers were based on the direct minimization of the nonlinear cost function to produce models with NARMAX (nonlinear Autoregressive Moving Average with exogenous inputs) structure. However, simplified MPC schemes may be obtained using models with Wiener and Hammerstein structures. This thesis presents new theoretical results which allow the development of MRI identification algorithms for models with Wiener and Hammerstein structures, without the need to perform the minimization of the nonlinear cost function. Besides the proof of theoretical results, new algorithms are developed and have their prediction capability statistical properties and performance in nonlinear MPC controllers evaluated.

Esta tese tem por objetivo a obtenção de modelos que apresentem melhor desempenho quando utilizados em controladores preditivos baseados em modelo (Model-based Predictive Control, MPC). Ao longo dos últimos 25 anos diversos trabalhos propuseram métodos baseados na minimização de uma função de predição múltiplos passos à frente, que se caracteriza por ser uma função não linear. Estes métodos foram denominados MPC Relevent Identification (MRI). A maioria destes artigos propõe técnicas para a obtenção de modelos lineares. Ao longo dos últimos 5 anos, alguns métodos, também baseados na minimização da função de predição múltiplos passos à frente, foram propostos para a identificação de modelos não lineares. Estes trabalhos são baseados na minimização direta da função de custo não linear, para obter com estrutura NARMAX (Nonlinear Autoregressive Moving Average with exogenous inputs). Entretanto, estruturas simplificadas de controladores MPC não lineares podem ser obtidas utilizando modelos com estruturas de Wiener e de Hammerstein. Esta tese apresenta novos resultados teóricos que permitem a obtenção de algoritmos de identificação MRI para modelos com estrutura de Wiener e Hammerstein, sem a necessidade de minimizar a função de custo não linear. Além da demonstração dos resultados teóricos, novos algoritmos são propostos tendo a sua capacidade de predição, propriedades estatísticas e aplicação em controladores MPC não lineares avaliadas. / This thesis focuses on obtaining models that may produce a better performance of Model-based Predictive Controllers (MPC). Several papers published in the last 25 years have proposed methods based on the minimization of multi-step ahead prediction functions, which are inherently nonlinear. These methods have been called MPC Relevant Identification (MRI). Most of the papers focused on obtaining linear models. In the last 5 years, some methods have been proposed to obtain nonlinear models based on the minimization of the same cost function. These papers were based on the direct minimization of the nonlinear cost function to produce models with NARMAX (nonlinear Autoregressive Moving Average with exogenous inputs) structure. However, simplified MPC schemes may be obtained using models with Wiener and Hammerstein structures. This thesis presents new theoretical results which allow the development of MRI identification algorithms for models with Wiener and Hammerstein structures, without the need to perform the minimization of the nonlinear cost function. Besides the proof of theoretical results, new algorithms are developed and have their prediction capability statistical properties and performance in nonlinear MPC controllers evaluated.

Orientador: Célia Aparecida dos Reis / Banca: Edson Donizete de Carvalho / Banca: Thiago Donda Rodrigues / Resumo: O mosquito Aedes aegypti é o principal vetor responsável por diversas arboviroses como a dengue, a febre amarela, o vírus zika e a febre chikungunya. Devido a sua resistência, adaptabilidade e proximidade ao homem, o Aedes aegypti é atualmente um dos maiores problemas de saúde pública no Brasil e nas Américas. Mesmo com os avanços e investimentos em pesquisas com vacinas, monitoramento, campanhas educativas e diversos tipos de controle deste vetor, ainda não existe um método eficaz para controlar e erradicar o mosquito. Portanto, esse trabalho destina-se ao auxílio na criação de estratégias para controlar esse agente transmissor, mediante a análise do espaço de estados e a estabilidade assintótica de uma dinâmica não linear para controle populacional do Aedes aegypti via a técnica de linearização de Lyapunov, além de apresentação de formas de prevenção e combate aos criadouros do mosquito. A dinâmica não linear proposta é uma dinâmica simplificada obtida de um modelo não linear existente na literatura, proposto por Esteva e Yang em 2005 e se baseia no ciclo de vida do mosquito, que é dividido em duas fases: fase imatura ou aquática (ovos, larvas e pupas) e fase alada (mosquitos adultos). Na fase adulta, os mosquitos são divididos em machos, fêmeas imaturas e fêmeas fertilizadas, sendo que a dinâmica proposta nesta dissertação de mestrado é baseada nos estudos efetuados por Reis desde 2016, obtendo um modelo simplificado no qual a soma das densidades das populações de fêmeas... / Abstract: The mosquito Aedes aegypti is the main vector responsible for several arboviruses such as dengue fever, yellow fever, zika virus and chikungunya fever. Due to its resistance, adaptability and proximity to humans, Aedes aegypti is currently one of the major public health problems in Brazil and the Americas. Even with the advances and investments in research with vaccines, monitoring, educational campaigns and various types of control of this vector, there is still no effective method to control and eradicate the mosquito. Therefore, this work is intended to aid in the creation of strategies to control this transmitting agent by analyzing the state space and the asymptotic stability of a nonlinear dynamics for population control of Aedes aegypti via the Lyapunov linearization technique to present ways of preventing and combating mosquito breeding sites. The proposed nonlinear dynamics is a simplified dynamics obtained from a nonlinear model existing in the literature, proposed by Esteva and Yang in 2005 and based on the life cycle of the mosquito, which is divided into two phases: immature or aquatic phase (eggs, larvae and pupae) and winged phase (adult mosquitoes). In the adult phase, mosquitoes are divided into males, immature females and fertilized females, and the dynamics proposed in this dissertation is based on studies carried out by Reis since 2016, obtaining a simplified model in which the sum of the densities of the populations of females immature and fertilized ... / Mestre

A Bayesian approach to system identification for structural control and health monitoring contains three main levels of inference, namely model assessment, joint state/parameter estimation and noise estimation. All of them have individually, or as a whole, been studied extensively for offline applications. In an online setting, the middle level of inference (joint state/parameter estimation) is performed using various algorithms such as the Kalman filter (KF), the extended Kalman filter (EKF), the Unscented Kalman filter (UKF), or particle filter (PF) methods. This problem has been explored in depth for structural dynamics. This dissertation focuses on the other two levels of inference, in particular on developing methods to perform them online, simultaneously to the joint state/parameter estimation. The quality of structural parameter estimates depends heavily on the choice of noise characteristics involved in the aforementioned online inference algorithms, hence the need for simultaneous online noise estimation. Model assessment, on the other hand, is an integral part of many engineering applications, since any analytical or numerical mathematical model used for predictive purposes is only an approximation of the real system. An online implementation of model assessment is valuable, amongst others, for structural control applications, and for identifying several models in parallel, some of which might be of deteriorating nature, thus generating some sort of alert. The performance of the proposed online techniques is evaluated using simulated and experimental data sets generated by nonlinear hysteretic systems. Upon completion of the study of hierarchical online system identification (diagnostic phase/estimation), a system/damage prognostic analysis (prognostic phase/prediction) is attempted using a gamma deterioration process. Prognostic analysis is still at a relatively early stage of development in the field of structural dynamics, but it can potentially provide useful insights regarding the lifetime of a dynamically excited structural system. The technique is evaluated on a data set recorded during an experiment involving a full-scale bridge pier under base excitation, tested to impending collapse.