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Dissertations / Theses on the topic 'Observation-Control'
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Machinek, Robert R. F. "Control and observation of DNA nanodevices." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:89e131dd-5179-4ebd-924b-2939f16681d5.
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The uniquely predictable and controllable binding mechanism of DNA strands has been exploited to construct a vast range of synthetic nanodevices, capable of autonomous motion and computation. This thesis proposes novel ideas for the control and observation of such devices. The first of these proposals hinges on introducing mismatched base pairs into toehold-mediated strand displacement – a fundamental primitive in most dynamic DNA devices and reaction networks. Previous findings that such mismatches can impede strand displacement are extended insofar as it is shown that this impediment is highly dependent on mismatch position. This discovery is examined in detail, both experimentally and through simulations created with a coarse-grained model of DNA. It is shown that this effect allows for kinetic control of strand displacement decoupled from reaction thermodynamics. The second proposal improves upon a previously presented strand displacement scheme, in which two strands perform displacement cooperatively. This scheme is extended to be cascadable, so that the output of one such reaction serves as input to the next. This scheme is implemented in reaction networks capable of performing fundamental calculations on directed graphs. The third proposal is exclusively concerned with a novel observation methodology. This method is based on single-molecule fluorescence microscopy, and uses quantum dots, a fluorescent type of semiconductor nanocrystal, as a label. These quantum dots display a set of characteristics particularly promising for single-molecule studies on the time- and length scales most commonly encountered in DNA nanotechnology. This method is shown to allow for highly precise measurements on static DNA devices. Preliminary data for the observation of a complex dynamic device is also presented.
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SCODINA, STEFANO. "Observation and control of PDE with disturbances." Doctoral thesis, Università degli Studi di Cagliari, 2012. http://hdl.handle.net/11584/266149.
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In this Thesis, the problem of controlling and Observing some classes of distributed parameter systems is addressed. The particularity of this work is to consider partial differential equations (PDE) under the effect of external unknown disturbances. We consider generalized forms of two popular parabolic and hyperbolic infinite dimensional dynamics, the heat and wave equations. Sliding-mode control is used to achieve the control goals, exploiting the robustness properties of this robust control technique against persistent disturbances and parameter uncertainties.
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PILLONI, ALESSANDRO. "Robust Observation and Control of Complex Networks." Doctoral thesis, Università degli Studi di Cagliari, 2014. http://hdl.handle.net/11584/266472.
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The problem of understanding when individual actions of interacting agents display to a coordinated collective behavior has receiving a considerable attention in many research fields. Especially in control engineering, distributed applications in cooperative environments
are achieving resounding success, due to the large number of relevant applications, such as formation control, attitude synchronization tasks and cooperative applications in large-scale systems.
Although those problems have been extensively studied in Literature, themost of classic approaches use to consider the unrealistic scenario in which networks always consist of
identical, linear, time-invariant entities. It’s clear that this assumption strongly approximates the effective behavior of a network. In fact agents can be subjected to parameter uncertainties,
unmodeled dynamics or simply characterized by proper nonlinear dynamics.
Therefore, motivated by those practical problems, the present Thesis proposes various approaches for dealing with the problem of observation and control in both the framework
of multi-agents and complex interconnected systems. The main contributions of this Thesis consist on the development of several algorithms based on concepts of discontinuous slidingmode control. This techniques can be employed for solving in finite-time problems of robust
state estimation and consensus-based synchronization in network of heterogenous nonlinear systems subjected to unknown but bounded disturbances and sudden topological changes.
Both directed and undirected topologies have been taken into account. It is worth to mention also the extension of the consensus problem to networks of agents governed by a class parabolic partial differential equation, for which, for the first time, a boundary-based robust local interaction protocol has been presented.
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Hovd, Tove Helene. "Modeling, state observation and control of Compression System." Thesis, Norwegian University of Science and Technology, Department of Engineering Cybernetics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-8716.
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The need of simulation models for physical systems is essential in all phases of its lifetime. During construction better decisions can be made and difficulties discovered. When running observers one can use the model to estimate states. Knowledge of the system is also needed to develop good control strategies. A compression system without surge avoidance recycling exists, and its mathematical development and simulation model was studied and simulated. Kalman filters were developed in theory, four filters were designed and lastly implemented. A study of industrial solutions for surge avoidance was performed, with attention to practical building, measurements, mathematical modeling and control. The study resulted in three simulation models for recycling that were fitted to the compressor at hand. Lastly a surge avoidance system was implemented on the model most likely to be built. A good simulation model of the existing compressor is available, and using this three well working Kalman filters were implemented. A fourth filter yielded non-unique and sometimes unstable estimates, and emphasized the importance of retrieving enough information from the measurements to estimate the correct state. All recycle system models used the characteristics of the existing compressor. The solution most likely to be implemented and form basis for a simulation model recycled gas directly downstream of the compressor. The other two models retrieved the recycled gas from the plenum, however this will change the dynamics of the system. These were not considered practical solutions for the specific system. The surge avoidance scheme worked well for production close to the surge line and small set-point changes. It also worked well for large changes in speed, but will surge if the speed becomes too low. The controller scheme did not work well when a large change in plenum throttle occurred, the recycle valve was then too slow. Future work consists of building a recycle loop, develop simulation model and implement surge avoidance scheme for academic purposes.
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Nagy, Gergely. "Observation, control, and automation of an OPCPA system." Thesis, Umeå universitet, Institutionen för fysik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-180702.
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Sanchez-Orta, Anand. "Modeling, observation and control of a flying machine." Compiègne, 2007. http://www.theses.fr/2007COMP1677.
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Ce travail de thèse porte sur la conception et la mise en œuvre de lois de commande pour le vol autonome de drones miniatures. Il s'agit aussi de proposer des algorithmes de commande basés sur l'estimation d'état pour résoudre les problèmes de fiabilité dans la mesure des capteurs utilisés sur les plates-formes expérimentales. Une loi de commande basée sur l'estimation d'état pour le modèle de l'avion PVTOL (Planar Vertical Take Off and Landing) est établie dans le but d'améliorer les mesures de capteurs peu précis. Plusieurs lois de commande basées sur des fonctions de saturation ont été proposées pour la stabilisation d'un hélicoptère à quatre rotors miniature. Des plateformes en temps réel ont été conçues et construites pour appliquer et tester les lois de commande proposées. Finalement nous avons développé et implémenté un hélicoptère original à deux rotors basculantsThis thesis is devoted to design and implement control laws which provide autonomous flight for Unmanned Aerial Vehic1es (UAVs). It also concerns to propose observer-based control laws in order to solve the localization problem. An observer-based control law for the PVTOL (Planar Vertical Take Off and Landing) aircraft model has been proposed in order to improve the sensor measurements. Several bounded control strategies based on saturation functions have been proposed in order to stabilize a quad-rotor mini rotorcraft. Experimental platforms have been designed and constructed to verify the proposed controllers. Finally, we have developed an original tiltrotor mini-aircraft
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BACCOLI, ANTONELLO. "Boundary control and observation of coupled parabolic PDEs." Doctoral thesis, Università degli Studi di Cagliari, 2016. http://hdl.handle.net/11584/266880.
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Reaction-diffusion equations are parabolic Partial Differential Equations (PDEs) which
often occur in practice, e.g., to model the concentration of one or more substances, distributed
in space, under the in
uence of different phenomena such as local chemical reactions,
in which the substances are transformed into each other, and diffusion, which causes
the substances to spread out over a surface in space. Certainly, reaction-diffusion PDEs
are not confined to chemical applications but they also describe dynamical processes of
non-chemical nature, with examples being found in thermodynamics, biology, geology,
physics, ecology, etc.
Problems such as parabolic Partial Differential Equations (PDEs) and many others
require the user to have a considerable background in PDEs and functional analysis before
one can study the control design methods for these systems, particularly boundary control
design.
Control and observation of coupled parabolic PDEs comes in roughly two settingsdepending
on where the actuators and sensors are located \in domain" control, where
the actuation penetrates inside the domain of the PDE system or is evenly distributed
everywhere in the domain and \boundary" control, where the actuation and sensing are
applied only through the boundary conditions.
Boundary control is generally considered to be physically more realistic because actuation
and sensing are nonintrusive but is also generally considered to be the harder problem,
because the \input operator" and the "output operator" are unbounded operators.
The method that this thesis develops for control of PDEs is the so-called backstepping
control method. Backstepping is a particular approach to stabilization of dynamic
systems and is particularly successful in the area of nonlinear control. The backstepping
method achieves Lyapunov stabilization, which is often achieved by collectively shifting
all the eigenvalues in a favorable direction in the complex plane, rather than by assigning
individual eigenvalues. As the reader will soon learn, this task can be achieved in a rather
elegant way, where the control gains are easy to compute symbolically, numerically, and
in some cases even explicitly.
In addition to presenting the methods for boundary control design, we present the dual
methods for observer design using boundary sensing. Virtually every one of our control
designs for full state stabilization has an observer counterpart. The observer gains are
easy to compute symbolically or even explicitly in some cases. They are designed in
such a way that the observer error system is exponentially stabilized. As in the case of
finite-dimensional observer-based control, a separation principle holds in the sense that a
closed-loop system remains stable after a full state stabilizing feedback is replaced by a
feedback that employs the observer state instead of the plant state.
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Kalyon, Gabriel. "Supervisory control of infinite state systems under partial observation." Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210032.
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A discrete event system is a system whose state space is given by a discrete set and whose state transition mechanism is event-driven i.e. its state evolution depends only on the occurrence of discrete events over the time. These systems are used in many fields of application (telecommunication networks, aeronautics, aerospace,). The validity of these systems is then an important issue and to ensure it we can use supervisory control methods. These methods consist in imposing a given specification on a system by means of a controller which runs in parallel with the original system and which restricts its behavior. In this thesis, we develop supervisory control methods where the system can have an infinite state space and the controller has a partial observation of the system (this implies that the controller must define its control policy from an imperfect knowledge of the system). Unfortunately, this problem is generally undecidable. To overcome this negative result, we use abstract interpretation techniques which ensure the termination of our algorithms by overapproximating, however, some computations. The aim of this thesis is to provide the most complete contribution it is possible to bring to this topic. Hence, we consider more and more realistic problems. More precisely, we start our work by considering a centralized framework (i.e. the system is controlled by a single controller) and by synthesizing memoryless controllers (i.e. controllers that define their control policy from the current observation received from the system). Next, to obtain better solutions, we consider the synthesis of controllers that record a part or the whole of the execution of the system and use this information to define the control policy. Unfortunately, these methods cannot be used to control an interesting class of systems: the distributed systems. We have then defined methods that allow to control distributed systems with synchronous communications (decentralized and modular methods) and with asynchronous communications (distributed method). Moreover, we have implemented some of our algorithms to experimentally evaluate the quality of the synthesized controllers. / Un système à événements discrets est un système dont l'espace d'états est un ensemble discret et dont l'évolution de l'état courant dépend de l'occurrence d'événements discrets à travers le temps. Ces systèmes sont présents dans de nombreux domaines critiques tels les réseaux de communications, l'aéronautique, l'aérospatiale. La validité de ces systèmes est dès lors une question importante et une manière de l'assurer est d'utiliser des méthodes de contrôle supervisé. Ces méthodes associent au système un dispositif, appelé contrôleur, qui s'exécute en parrallèle et qui restreint le comportement du système de manière à empêcher qu'un comportement erroné ne se produise. Dans cette thèse, on s'intéresse au développement de méthodes de contrôle supervisé où le système peut avoir un espace d'états infini et où les contrôleurs ne sont pas toujours capables d'observer parfaitement le système; ce qui implique qu'ils doivent définir leur politique de contrôle à partir d'une connaissance imparfaite du système. Malheureusement, ce problème est généralement indécidable. Pour surmonter cette difficulté, nous utilisons alors des techniques d'interprétation abstraite qui assurent la terminaison de nos algorithmes au prix de certaines sur-approximations dans les calculs. Le but de notre thèse est de fournir la contribution la plus complète possible dans ce domaine et nous considèrons pour cela des problèmes de plus en plus réalistes. Plus précisement, nous avons commencé notre travail en définissant une méthode centralisée où le système est contrôlé par un seul contrôleur qui définit sa politique de contrôle à partir de la dernière information reçue du système. Ensuite, pour obtenir de meilleures solutions, nous avons défini des contrôleurs qui retiennent une partie ou la totalité de l'exécution du système et qui définissent leur politique de contrôle à partir de cette information. Malheureusement, ces méthodes ne peuvent pas être utilisées pour contrôler une classe intéressante de systèmes: les sytèmes distribués. Nous avons alors défini des méthodes permettant de contrôler des systèmes distribués dont les communications sont synchrones (méthodes décentralisées et modulaires) et asynchrones (méthodes distribuées). De plus, nous avons implémenté certains de nos algorithmes pour évaluer expérimentalement la qualité des contrôleurs qu'ils synthétisent.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Wirgau, Scott Arthur. "Remote Observation and Control of a Shake Table Experiment." NCSU, 2003. http://www.lib.ncsu.edu/theses/available/etd-05142003-003926/.
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Laboratory experiences, i.e. visualization of material covered in class and hands-on use of equipment, are especially advantageous to engineering classes such as structural mechanics. Unfortunately it is sometimes difficult for on-campus students to be taken to a lab setting and impossible for those who are off campus due to work, disabilities, or other complexities and taking class through distance education. This project describes a shake table experiment that is being converted to a distance-learning environment. This will include remote access, control, and protection from misuse. An aspect of the project that differentiates it from simple remote viewing of a lecture or experiment is the need to control the experiment and to protect against the possibility of damage occurring to this particular setup if left unmonitored. This last point necessitates the inclusion of sufficient safety protocols. The environment must allow remote controlling of the system, multi-user viewing, data saving, and download capabilities. The technology selected for use in this project is the LabVIEW programming environment in conjunction with its real time counterpart, LabVIEW RT. By using this language, practical and intuitive control panels coupled with easy to follow data flow block diagrams are made possible. The LabVIEW code likewise handles the data acquisition. The information sent and received through the DAQ card is processed by LabVIEW RT code embedded in the real time processor. The information is then sent to a host computer for saving, visualization, and distribution to remote clients. This visualization includes an oscilloscope for displaying the accelerations from both the table and the structure residing on the table. Further visualization is given by way of a video camera. The code must be made safe from unauthorized usage in addition to allowing for the university network to remain protected. This research outlines in detail the setup required and programs needed to implement such a system and presents the information in a manner that can be helpful regardless of the programming language chosen.
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Dixit, Ravindra. "Sliding Mode Observation and Control for Semiactive Vehicle Suspensions." NCSU, 2001. http://www.lib.ncsu.edu/theses/available/etd-20011116-144808.
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Dixit, Ravindra Krishna. Sliding Mode Observation and Control for Semiactive Vehicle Suspen-sions.(Under the direction of Dr. Greg Buckner).This thesis investigates the application of robust, nonlinear observation and control strategies,namely sliding mode observation and control (SMOC), to semiactive vehicle suspensions using amodel reference approach. The vehicle suspension models include realistic nonlinearities in thespring and magnetorheological (MR) damper elements, and the nonlinear reference models incorpo-rateskyhook damping. Since full state measurement is difficult to achieve in practice, a sliding modeobserver (SMO) that requires only suspension deflection as a measured input is developed. The per-formanceand robustness of sliding mode control (SMC), SMO, and SMOC is demonstrated throughcomprehensive computer simulations and compared to popular alternatives. The results of thesesimulations reveal the benefits of sliding mode observation and control for improved ride quality,and should be directly transferable to commercial semiactive vehicle suspension implementations.
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Contreras, Martinez Dimel Arturo. "Observation and control of a ball on a tilting." Master's thesis, Pontificia Universidad Católica del Perú, 2017. http://tesis.pucp.edu.pe/repositorio/handle/123456789/9641.
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The ball and plate system is a nonlinear MIMO system that has interesting characteristics
which are also present in aerospace and industrial systems, such as: instability, subactuation,
nonlinearities such as friction, backlash, and delays in the measurements.
In this work, the modeling of the system is based on the Lagrange approach. Then it is
represented in the state-space form with plate accelerations as inputs to the system. These
have a similar effect as applying torques. In addition, the use of an internal loop of the servo
system is considered. From the obtained model, we proceed to carry out the analysis of
controllability and observability resulting in that the system is globally weak observable and
locally controllable in the operating range. Then, the Jacobi linearization is performed to use
the linearized model in the design of linear controllers for stabilization.
On the other hand, analyzing the internal dynamics of the ball and plate system turns out
to be a non-minimum phase system, which makes it difficult to design the tracking control
using the exact model. This is the reason why we proceed to make approximations. Using the
approximate model, nonlinear controllers are designed for tracking using different approaches
as: feedback linearization for tracking with and without integral action, backstepping and
sliding mode. In addition, linear and nonlinear observers are designed to provide full state
information to the controller.
Simulation tests are performed comparing the different control and observation approaches.
Moreover, the effect of the delay in the measurement is analyzed, where it is seen that the
greater the frequency of the reference signal the more the error is increased. Then, adding the
Smith predictor compensates the delay and reduces the tracking error.
Finally, tests performed with the real system. The system was successfully controlled for
stabilization and tracking using the designed controllers. However, it is noticed that the effect
of the friction, the spring oscillation and other non-modeled characteristics significantly affect
the performance of the control.Tesis
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Yan, Zhang. "Control and observation of electric machines by sliding modes." Columbus, Ohio : Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1039227737.
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Thesis (Ph. D.)--Ohio State University, 2002.Title from first page of PDF file. Document formatted into pages; contains xv, 156 p.; also includes graphics (some col.). Includes abstract and vita. Co-advisors: Vadim I. Utkin, Giorgio Rizzoni, Dept. of Electrical Engineering. Includes bibliographical references (p. 153-156).
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Singh, Satnesh. "Discrete-time stochastic sliding mode control using functional observation." Thesis, IIT Delhi, 2019. http://eprint.iitd.ac.in:80//handle/2074/8122.
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Martin, Gregory A. "Modeling, control, and observation of sampled-data nonlinear systems under delayed control and sensing." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/13914.
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Johnson, Clifford Edgar. "Adaptive control of combution instabilities using real-time modes observation." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-03232006-223052/.
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Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2006.Zinn, Ben, Committee Chair ; Glezer, Ari, Committee Member ; Shelton, Samuel, Committee Member ; Lieuwen, Tim, Committee Member ; Neumeier, Yedidia, Committee Member.
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Kleinert, Tobias. "Modelling, state observation and control of simulated counterflow chromatographic separations." Berlin Logos-Verl, 2005. http://deposit.ddb.de/cgi-bin/dokserv?id=2800336&prov=M&dok_var=1&dok_ext=htm.
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Kleinert, Tobias. "Modelling, state observation and control of simulated counterflow chromatographic separations /." Berlin : Logos, 2006. http://deposit.ddb.de/cgi-bin/dokserv?id=2800336&prov=M&dok_var=1&dok_ext=htm.
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Cox, S. "Observation and control of the low temperature superstructure in manganites." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598107.
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The work in this dissertation is focused on the insulating side of the La1-xCaxMnO3 and Pr1-xCaxMnO3 phase diagram, in particular on the low temperature ‘charge ordered’ phase. This phase exhibits a superstructure whose periodicity depends on the doping of the sample, among other factors. Firstly the microscopic nature of the charge ordered phase is probed using a variety of techniques including TEM, heat capacity measurements and neutron diffraction measurements. Secondly, the charge ordered phase is controlled via the manipulation of strain. In the first set of experiments, polycrystalline samples are subject to extrinsic effects, and so although it is possible to observe spatial variations in the superstructure, it is not possible to systematically control possible causes of the variation. By growing thin films it was possible to control the level of strain in the film, which is one of the extrinsic effects. This creates a spatial variation in the superstructure which could be observed. The results of this experiment can then be used to provide insight into the small scale nature of the charge ordering superstructure.
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Becerra, Gerardo de Jesus. "Control and observation of switched systems. Application to power converters." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI123.
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En matière de production énergétique, les tendances actuelles indiquent que la part de marché mondiale des énergies renouvelables continuera d’augmenter du fait de l’amélioration continue de l’efficacité des équipements et de la réduction de leurs coûts. Les convertisseurs de puissance jouent un rôle fondamental dans le fonctionnement des réseaux électriques car ils permettent les transferts d'énergie entre les sources, les éléments de stockage et les charges. Ces dispositifs doivent répondre à des exigences particulières d'efficacité, de robustesse et de stabilité pour garantir un fonctionnement correct. Le travail présenté dans ce mémoire est centré sur deux problèmes particuliers liés au comportement des convertisseurs de puissance : la commande et l’observation. Ces problèmes sont difficiles à résoudre en raison des non-linéarités et des phénomènes physiques complexes présents dans ces composants. Le modèle mathématique utilisé pour représenter les convertisseurs de puissance est le modèle dit à commutation. Sur la base de ce modèle, nous exploitons des outils abordés dans des problématiques telles que la stabilité de Lyapunov, la méthode des moments, la géométrie algébrique et le filtrage direct. Nous proposons des approches novatrices pour commander et observer ces systèmes commutés. Nous introduisons notamment la notion de moments de relaxation pour les systèmes commutés. Ces représentations permettent d’obtenir des modèles permettant d'établir une cartographie de l’entrée de commutations dans l'espace des moments. Cette carte supprime la non-linéarité associée à l'entrée de commutation et fournit un modèle plus approprié pour effectuer les calculs numériques de la commande. C'est l'idée fondamentale de la méthode de commande à variation de paramètres proposée. Après avoir calculé un signal de commande pour le modèle relaxé, le signal d'entrée pour le système commuté peut alors être déduit. Cette approche a montré de bonnes performances en termes de suivi de référence et de stabilité. Une approche reposant sur les données pour l'observation des systèmes commutés est proposée. Cette méthode implique la synthèse d'un filtre direct qui calcule les limites du cas le plus défavorable sur l'erreur d'estimation. Cette méthode est appliquée au cas des convertisseurs de puissance fonctionnant en mode continu et discontinu. Une mise en oeuvre pratique est effectuée et ses performances sont comparées à d’autres méthodes d’estimationCurrent trends in global energy production indicate that renewables will continue to increase their market share due to continuous efficiency improvements and cost reductions. Power converters constitute the interfaces that enable energy transfers in microgrids between sources, storage and loads, playing a fundamental role in their operation. These devices are required to meet particular efficiency, robustness and stability requirements to guarantee a proper operation. The present work is focused on two particular problems present in the operation of power converters: control and observation. These problems are hard to solve because of the nonlinearities and complex behaviors present in power converters. The mathematical model used to represent power converters is the switched system. Based on this model we take elements from subjects like Lyapunov stability, the method of moments, algebraic geometry and direct filtering, and propose novel approaches to control and observation of switched systems. We introduce moment relaxations of switched systems. These representations allow to obtain models where the switching input is mapped to a moment space. This map removes the nonlinearity associated to the switching input and yields a model which is more suitable for performing numerical computations. This is the fundamental idea in the proposed parameter-varying control method. After computing a control signal for the relaxed model, the control signal for the switched system can be recovered. This approach has shown good performance with respect to reference tracking and stability. A data-driven approach for the observation of switched systems is proposed. This method involves the design of a direct filter that computes worst-case bounds on the estimation error. This method is applied to the case of power converters operating in continuous and discontinuous modes. A practical implementation is described, and its performance is compared with other estimation approaches
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Rosero, ibarra Nadia. "Modeling and observation applied to physiology-aware control for cycling." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT089/document.
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De nos jours, la plupart des assistances électriques pour vélos sont principalement basées sur des mesures de variables mécaniques. Cette thèse se concentre sur l'analyse du cycliste et du vélo dans son ensemble, afin de concevoir une loi de commande qui prenne en compte des contraintes physiologiques. En ce sens, la relation entre les indices physiologiques et les variables mécaniques est abordée. En particulier, dynamique d'échange de gaz pendant le pédalage est modélisée et analysée. Le modèle obtenu est linéaire à paramètres variables en temps discret. Les données mesurées de différents tests de cyclisme efectués au sein du GIPSA-Lab sont utilisées pour son calibration. La méthodologie d'identification paramétrique est développée comme solution à une séquence de problèmes d'optimisation non linéaire et non contraints. Le modèle dynamique d'échange de gaz fait référence à la détermination de la production excessive de dioxyde de carbone, qui est considérée comme un état physiologique indésirable du cycliste. En outre, un observateur de la production de dioxyde de carbone est mis en oeuvre en utilisant des mesures de la consommation d'oxygène et de la puissance de pédalage, ce qui fournit un intervalle déterministe contenant l'état réel. Enfin, une méthode est présentée pour trouver les conditions suffisantes sur la puissance de pédalage qui garantissent des niveaux admissibles de production de dioxyde de carboneNowadays, most of the electrical assistances for bicycles are mainly based onmeasurements of mechanical variables. In this dissertation, cyclist and bicycle are considered as a whole energetic system in order to conceive physiology-aware control strategies. In this sense, the relationships between physiological indices and mechanical variables are studied. In particular, the gas exchange dynamics during cycling is modeled and analysed. The obtained model is discrete-time and linear parameter varying. Measured data of different cycling tests performed in GIPSA-Lab are used for its calibration. A methodology for parametric identification is developed as a solution of a sequence of non-linear unconstrained optimization problems. The gas exchange dynamical model allows the determination of excess carbon dioxide production, which is considered as an unsuitable physiological-state of the cyclist. Furthermore, a set-membership observer of carbon dioxide production is implemented using measurements of oxygen consumption and pedal power. It provides a deterministic interval which contains the real state. Finally, this thesis presents a method for finding the suficient conditions on the pedal power that guarantee admissible levels of carbon dioxide production
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Machinek, Lars Raoul [Verfasser], and R. [Akademischer Betreuer] Schnaubelt. "Additive control and observation systems / Lars Raoul Machinek ; Betreuer: R. Schnaubelt." Karlsruhe : KIT-Bibliothek, 2017. http://d-nb.info/1132997658/34.
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Husband, Peter Antony. "The experimental observation, prediction and control of polyethylene extrudate die swell." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621884.
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Blanco, Rodríguez David. "Modelling and observation of exhaust gas concentrations for diesel engine control." Doctoral thesis, Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/32666.
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La Tesis Doctoral estudia la observaci'on en tiempo real de la concentraci'on en el colector de escape de 'oxidos de nitr'ogeno (NOx) y del dosado en motores
diesel sobrealimentados (¿
'1
). Para ello se combinan dos fuentes de informaci'on diferentes:
¿ Sensores capaces de proporcionar una media de dichas variables,
¿ y modelos orientados a control que estiman estas variables a partir de otras
medidas del motor.
El trabajo parte de la evaluaci'on de la precisi'on de los sensores, realizada mediante la comparaci'on de su medida con la proporcionada por equipos anal'¿ticos de
alta precisi'on, que son usados como est'andares de calibraci'on est'atica. Tambi'en se
desarrollan en la Tesis m'etodos para la calibraci'on de la din'amica del sensor; dichos m'etodos permiten identi¿car un modelo de comportamiento del sensor y revelar
su velocidad de respuesta. En general, estos sensores demuestran ser precisos pero
relativamente lentos.
Por otra parte, se proponen modelos r'apidos para la estimaci'on de NOx y ¿
'1
.
Estos m'etodos, basados en relaciones f'¿sicas, tablas de par'ametros y una serie de
correcciones, emplean las medidas proporcionadas por otros sensores con el ¿n de
proporcionar una estimaci'on de las variables de inter'es. Los modelos permiten una
estimaci'on muy r'apida, pero resultan afectados por efectos de deriva que comprometen
su precisi'on.
Con el ¿n de aprovechar las caracter'¿sticas din'amicas del modelo y mantener
la precisi'on en estado estacionario del sensor, se proponen t'ecnicas de fusi'on de la
informaci'on basadas en la aplicaci'on de ¿ltros de Kalman (KF). En primer lugar, se
dise¿na un KF capaz de combinar ambas fuentes de informaci'on y corregir en tiempo
real el sesgo entre las dos se¿nales. Posteriormente, se estudia la adaptaci'on en tiempo
real de los par'ametros del modelo con el ¿n de corregir de forma autom'atica los
problemas de deriva asociados al uso de modelos.
Todos los m'etodos y procedimientos desarrollados a lo largo de la presente Tesis
Doctoral se han aplicado de forma experimental a la estimaci'on de NOx y ¿
'1
. De
forma adicional, la Tesis Doctoral desarrolla aspectos relativos a la transferencia de
estos m'etodos a los motores de serie.The dissertation covers the problem of the online estimation of diesel engine exhaust concentrations of NOx and '1. Two information sources are utilised: ¿ on-board sensors for measuring NOx and '1, and ¿ control oriented models (COM) in order to predict NOx and '1. The evaluation of the static accuracy of these sensors is made by comparing the outputs with a gas analyser, while the dynamics are identified on-board by perform- ing step-like transitions on NOx and '1 after modifying ECU actuation variables. Different methods for identifying the dynamic output of the sensors are developed in this work; these methods allow to identify the time response and delay of the sensors if a sufficient data set is available. In general, these sensors are accurate but present slow responses. Afterwards, control oriented models for estimating NOx and '1 are proposed. Regarding '1 prediction, the computation is based on the relative fuel-to-air ratio, where fuel comes from an ECU model and air mass flow is measured by a sensor. For the case of NOx, a set-point relative model based on look-up tables is fitted for representing nominal engine emissions with an exponential correction based on the intake oxygen variation. Different corrections factor for modeling other effects such as the thermal loading of the engine are also proposed. The model is able to predict NOx fast with a low error and a simple structure. Despite of using models or sensors, model drift and sensor dynamic deficiencies affect the final estimation. In order to solve these problems, data fusion strategies are proposed by combining the steady-state accuracy of the sensor and the fast estimation of the models by means of applying Kalman filters (KF). In a first approach, a drift correction model tracks the bias between the model and the sensor but keeping the fast response of the model. In a second approach, the updating of look-up tables by using observers is coped with different versions based on the extended Kalman filter (EKF). Particularly, a simplified KF allows to observe the parameters with a low computational effort. Finally, the methods and algorithms developed in this work are combined and applied to the estimation of NOx and '1. Additionally, the dissertation covers aspects relative to the implementation of the methods in series engines.
Blanco Rodríguez, D. (2013). Modelling and observation of exhaust gas concentrations for diesel engine control [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/32666
TESIS
Premiado
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Hofman, J. T. "Development of an observation and control system for industrial laser cladding." Enschede : University of Twente [Host], 2009. http://doc.utwente.nl/60627.
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Bosso, Alessandro <1992>. "Advanced Computational-Effective Control and Observation Schemes for Constrained Nonlinear Systems." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amsdottorato.unibo.it/9428/1/bosso_alessandro_tesi.pdf.
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Constraints are one of the most common challenges that must be faced in control systems design. The sources of constraints in engineering applications are several, ranging from actuator saturations to safety restrictions, from imposed operating conditions to trajectory limitations. Their presence cannot be avoided, and their importance grows even more in high performance or hazardous applications. As a consequence, a common strategy to mitigate their negative effect is to oversize the components. This conservative choice could be largely avoided if the controller was designed taking all limitations into account. Similarly, neglecting the constraints in system estimation often leads to suboptimal solutions, which in turn may negatively affect the control effectiveness. Therefore, with the idea of taking a step further towards reliable and sustainable engineering solutions, based on more conscious use of the plants' dynamics, we decide to address in this thesis two fundamental challenges related to constrained control and observation.
In the first part of this work, we consider the control of uncertain nonlinear systems with input and state constraints, for which a general approach remains elusive.
In this context, we propose a novel closed-form solution based on Explicit Reference Governors and Barrier Lyapunov Functions. Notably, it is shown that adaptive strategies can be embedded in the constrained controller design, thus handling parametric uncertainties that often hinder the resulting performance of constraint-aware techniques.
The second part of the thesis deals with the global observation of dynamical systems subject to topological constraints, such as those evolving on Lie groups or homogeneous spaces. Here, general observability analysis tools are overviewed, and the problem of sensorless control of permanent magnets electrical machines is presented as a case of study. Through simulation and experimental results, we demonstrate that the proposed formalism leads to high control performance and simple implementation in embedded digital controllers.
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Fahnestock, Mark Allen Kamb Barclay. "Hydrologic control of sliding velocity in two Alaskan glaciers : observation and theory /." Diss., Pasadena, Calif. : California Institute of Technology, 1991. http://resolver.caltech.edu/CaltechETD:etd-07182006-134101.
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CALVIA, ALESSANDRO. "Optimal control of pure jump Markov processes with noise-free partial observation." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2018. http://hdl.handle.net/10281/199013.
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La presente tesi tratta un problema di controllo ottimo su orizzonte temporale infinito per un processo di puro salto Markoviano e con osservazione parziale di tipo noise-free. È definita una coppia di processi stocastici, detti processo non osservato o segnale e processo osservato o dei dati. Il segnale è un processo di puro salto Markoviano a tempo continuo, a valori in uno spazio metrico completo e separabile, di cui è nota la misura controllata dei tassi di transizione. Il processo osservato prende valori in un ulteriore spazio metrico completo e separabile ed è di tipo noise-free. Con questa espressione si intende che i suoi valori a ogni tempo t sono funzione dei corrispondenti valori al tempo t del processo non osservato. Si fa l’ipotesi che tale funzione sia un’applicazione deterministica e, senza perdita di generalità, suriettiva tra gli spazi di stato dei processi non osservato e osservato. L’obiettivo è controllare la dinamica del processo non osservato, ossia la sua misura controllata dei tassi di transizione, attraverso un processo di controllo, il quale prende valori nell’insieme delle misure di probabilità di Borel su uno spazio metrico compatto, detto spazio delle azioni di controllo. I controlli ammissibili per il nostro problema sono i processi appena descritti che siano anche prevedibili rispetto alla filtrazione naturale del processo osservato. Il processo di controllo è scelto in questa classe al fine di minimizzare un funzionale costo con fattore di sconto su orizzonte temporale infinito. L’estremo inferiore di tale funzionale costo tra tutti i controlli ammissibili è la funzione valore.
Per studiare la funzione valore è necessario un passo preliminare. Il problema di controllo ottimo a osservazione parziale deve essere espresso come problema a osservazione completa. Ciò è possibile grazie allo studio del processo di filtraggio, un processo a valori in misure che fornisce a ogni istante t la legge condizionale del processo non osservato data l’osservazione disponibile fino al tempo t (rappresentata dalla filtrazione naturale del processo osservato al tempo t). Si dimostra che il processo di filtraggio soddisfa un’equazione differenziale stocastica esplicita e si caratterizza tale processo come Piecewise Deterministic Markov Process, nel senso di Davis.
Allo scopo di trattare il processo di filtraggio come variabile di stato, si studia un problema di controllo separato. Questo è definito come problema a tempo discreto e si mostra che è equivalente a quello originario, nel senso che le rispettive funzioni valore sono legate da una formula esplicita. Si dimostra, inoltre, che i controlli ammissibili per il problema originario e le strategie ammissibili di quello separato hanno una ben precisa struttura ed esiste una specifica relazione tra di essi.
Si caratterizza, quindi, la funzione valore del problema di controllo separato (dunque, indirettamente, la funzione valore del problema originario) come unico punto fisso di un operatore di contrazione, il quale agisce dallo spazio delle funzioni continue e limitate sullo spazio di stato del processo di filtraggio in sé. Di conseguenza, si dimostra che la funzione valore è continua e limitata.
Si studia anche il caso di un processo non osservato dato da una catena di Markov a stati finiti. In questo contesto, si mostra che la funzione valore del problema di controllo separato è uniformemente continua sullo spazio di stato del processo di filtraggio e che è l’unica soluzione viscosa vincolata (nel senso di Soner) di un’equazione di Hamilton-Jacobi-Bellman. Si dimostra, inoltre, che esiste un controllo ottimo ordinario, ossia un processo di controllo che prende valori nell’insieme delle azioni di controllo, e che tale processo è un piecewise open-loop control nel senso di Vermes.This thesis is concerned with an infinite horizon optimal control problem for a pure jump Markov process with noise-free partial observation. We are given a pair of stochastic processes, named unobserved or signal process and observed or data process. The signal process is a continuous-time pure jump Markov process, taking values in a complete and separable metric space, whose controlled rate transition measure is known. The observed process takes values in another complete and separable metric space and is of noise-free type. With this we mean that its values at each time t are given as a function of the corresponding values at time t of the unobserved process. We assume that this function is a deterministic and, without loss of generality, surjective map between the state spaces of the signal and data processes. The aim is to control the dynamics of the unobserved process, i.e. its controlled rate transition measure, through a control process, taking values in the set of Borel probability measures on a compact metric space, named set of control actions. We take as admissible controls for our problem all the processes of this kind that are also predictable with respect to the natural filtration of the data process. The control process is chosen in this class to minimize a discounted cost functional on infinite time horizon. The infimum of this cost functional among all admissible controls is the value function. In order to study the value function a preliminary step is required. We need to recast our optimal control problem with partial observation into a problem with complete observation. This is done studying the filtering process, a measure-valued stochastic process providing at each time t the conditional law of the unobserved process given the available observations up to time t (represented by the natural filtration of the data process at time t). We show that the filtering process satisfies an explicit stochastic differential equation and we characterize it as a Piecewise Deterministic Markov Process, in the sense of Davis. To treat the filtering process as a state variable, we study a separated optimal control problem. We introduce it as a discrete-time one and we show that it is equivalent to the original one, i.e. their respective value functions are linked by an explicit formula. We also show that admissible controls of the original problem and admissible policies of the separated one have a specific structure and there is a precise relationship between them. Next, we characterize the value function of the separated control problem (hence, indirectly, the value function of the original control problem) as the unique fixed point of a contraction mapping, acting from the space of bounded continuous function on the state space of the filtering process into itself. Therefore, we prove that the value function is bounded and continuous. The special case of a signal process given by a finite-state Markov chain is also studied. In this setting, we show that the value function of the separated control problem is uniformly continuous on the state space of the filtering process and that it is the unique constrained viscosity solution (in the sense of Soner) of a Hamilton-Jacobi-Bellman equation. We also prove that an optimal ordinary control exists, i.e. a control process taking values in the set of control actions, and that this process is a piecewise open-loop control in the sense of Vermes.
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饒勇 and Yong Rao. "The astronomical observation system of 12" telescope: its automatic control system and astronomical application." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1997. http://hub.hku.hk/bib/B31214587.
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Lu, Fei [Verfasser]. "Induction Machine Control: State Observation, Electromagnetic Analysis, Modeling for Control, Finite Element Simulation, and Rotor Temperature Estimation / Fei Lu." Düren : Shaker, 2021. http://d-nb.info/1240853866/34.
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Onoda, Masami. "Monitoring International Regimes by Global Satellite Earth Observation: From arms control to climate change." 京都大学 (Kyoto University), 2009. http://hdl.handle.net/2433/123785.
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Easun, Timothy L. "Solvatochromic control and time-resolved infrared spectroscopic observation of photophysical processes in polynuclear complexes." Thesis, University of Sheffield, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440943.
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Schmidt, Eric Grayson. "Observation and control of ion motion in fourier transform ion cyclotron resonance mass spectrometry /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Rao, Yong. "The astronomical observation system of 12" telescope : its automatic control system and astronomical application /." Hong Kong : University of Hong Kong, 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B1877698X.
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Kuhn, Robin Merritt. "Assessing the Stimulus Control of Observers." Thesis, University of North Texas, 2009. https://digital.library.unt.edu/ark:/67531/metadc12146/.
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The science of behavior analysis relies heavily on direct observation. Human observers are typically used to measure behavior in applied settings. Although the use of human observers is beneficial in many regards, it also presents challenges. Of primary concern is the extent to which the data generated by observers actually corresponds to the behavioral events of interest, and the implications this may have in terms of replication. This study assessed the effects that labels, definitions, and examples and non-examples of two different modalities had on observer accuracy, consistency, and agreement. Results showed that current practices in observer training may require refinement to ensure high observer accuracy, consistency, and agreement. Suggestions for how to improve the desired stimulus control of observers are provided.
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Mauntz, Wolfgang [Verfasser]. "A Contribution to Observation and Time-optimal Control of Emulsion Co-Polymerization Reactions / Wolfgang Mauntz." Aachen : Shaker, 2010. http://d-nb.info/1081885971/34.
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Oliveira, André Marcorin de. "Estimating and control of Markov jump linear systems with partial observation of the operation mode." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3139/tde-01032019-144518/.
Full textAbstract:
In this thesis, we present some contributions to the Markov jump linear systems theory in a context of partial information on the Markov chain. We consider that the state of the Markov chain cannot be measured, but instead there is only an observed variable that could model an asynchronous phenomenon between the application and the plant, or a simple fault detection and isolation device. In this formulation, we investigate the problem of designing controllers and filters depending only on the observed variable in the context of H2, H?, and mixed H2/H? control theory. Numerical examples and academic applications are presented for active-fault tolerant control systems and networked control systems.Nesta tese, apresentamos algumas contribuições para a teoria de sistemas lineares com saltos markovianos em um contexto de observação parcial da cadeia de Markov. Consideramos que o estado da cadeia de Markov não pode ser medido, porém existe uma variável observada que pode modelar um fenômeno assíncrono entre a aplicação e a planta, ou ainda um dispositivo de detecção de falhas simples. Através desse modelo, investigamos o problema da síntese de controladores e filtros que dependem somente da variável observada no contexto das teorias de controle H2, H?, e misto H2/H?. Exemplos numéricos e aplicações acadêmicas são apresentadas no âmbito dos sistemas de controle tolerantes a falhas e dos sistemas de controle através da rede.
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Haws, Jordan. "Command, Control and Telemetry for Utah State University's Scintillation Prediction Observation Research Task (SPORT) Mission." DigitalCommons@USU, 2020. https://digitalcommons.usu.edu/etd/7711.
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The Scintillation Prediction Observation Research Task (SPORT) is a joint United States of America (USA) and Brazil small satellite mission to address the further under-standing of the preconditions leading to equatorial plasma bubbles. Utah State University (USU) is supplying four instruments towards this SPORT mission. These four instruments will allow measurements of the electric field and plasma density in the ionosphere which will help understand what gives rise to plasma bubbles in the ionosphere.
This thesis will discuss the command, control, and telemetry communications needed to operate the SPORT USU instruments. It will cover an overview of the instruments involved, how the instruments are controlled specifically, what commands were needed to run the instruments, what telemetry data was produced and how it was transmitted to the ground station, and how the data is made useful. The design process, challenges, and solutions to this system and project will also be discussed.
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Riani, Akram. "Commande et observation des exosquelettes pour la rééducation fonctionnelle du membre supérieur." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLV026/document.
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Cette thèse s’adresse à la problématique de contrôle/commande et d'observation des exosquelettes du membre supérieur pour l’assistance à la mobilité des personnes qui souffrent d'un déficit moteur, caractérisé par une perte totale ou partielle des capacités motrices. Le robot utilisé pour les validations est conçu par RB3D dans le but des travaux de recherches sur les lois de commandes pour la rééducation du membre supérieur au sien du Laboratoire LISSI (Laboratoire Images, Signaux et Systèmes Intelligents) de l’UPEC, appelé ULEL (Upper Limb Exoskeleton of LISSI).Deux approches de commande d'exosquelettes pour la rééducation fonctionnelle du membre supérieur ont été proposées. La première commande est conçue sur la base d’un estimateur en-ligne des paramètres dynamiques. Cette méthode d'adaptation permet d'améliorer les performances de contrôle de ce système, et de compenser les erreurs paramétriques dues au couplage de l'exosquelette avec le membre humain.La deuxième contribution consiste en une stratégie de commande robuste basée sur les modes glissants. Cette stratégie non-linéaire, garantie la convergence des erreurs de poursuite vers zéro en temps fini lorsque le régime de glissement est atteint. Ce type de commande est connu par sa robustesse vis-à-vis les variations paramétriques et les perturbations externes. L'efficacité de la méthode proposée est démontrée expérimentalement pour le mode de rééducation passif.Dans la dernière partie de la thèse, un observateur en mode glissant d'ordre supérieur est proposé pour estimer les couples d'interactions homme-exosquelette. L'observateur proposé est capable d'estimer les efforts au niveau de l'interface d'interaction entre l'exosquelette et le membre humain, en utilisant les mesures de position et l'entrée de commande. Les résultats obtenus montrent l’efficacité des solutions proposées sur l’exosquelette ULELThis thesis addresses the problem of control of an upper limb exoskeleton for mobility assistance of people who suffer from a motor deficit, characterized by a total or partial loss of motor skills. The robot used is designed by RB3D for the purpose of research work on the control laws for the rehabilitation of the upper limb at LISSI Laboratory (Laboratory Images, Signals and Intelligent Systems) of the UPEC university; this exoskeleton is called ULEL (Upper Limb Exoskeleton of LISSI).Two approaches to control exoskeletons for functional rehabilitation of the upper limb have been proposed. The first control is based on an online estimator of dynamic parameters. This adaptation method makes it possible to improve the control performance of this system, and to compensate for parametric errors due to coupling the exoskeleton with the human limb.The second contribution consists of a robust control strategy based on sliding modes. This nonlinear strategy guarantees the convergence of tracking errors to zero in finite time when the sliding mode is reached. This type of control is known by its robustness with respect to parametric variations and external disturbances. The effectiveness of the proposed method is experimentally demonstrated for the passive rehabilitation mode.Finally, in the last part of this thesis, a higher order sliding mode observer is proposed to estimate interactions torques of the human-exoskeleton system. The proposed observer is able to estimate the forces at the interaction interface between the exoskeleton and the human limb, using the position measurements and the control input. The obtained results show the effectiveness of the proposed solutions using the exoskeleton ULEL
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Shin, Dong-Ryeol. "Optimal control of a finite state markov process under counting observation and applications to integrated networks." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/13081.
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Quintanar, Guzmán Serket. "Nonlinear observation and control of a lightweight robotic manipulator actuated by shape memory alloy (SMA) wires." Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0050/document.
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Au cours de la dernière décennie, l’industrie des véhicules aériens sans pilote (UAV) a connu une croissance et une diversification immenses. De nos jours, nous trouvons des applications basées sur les drones dans un large éventail d’industries, telles que les infrastructures, l’agriculture, les transports, etc. Ce phénomène a suscité un intérêt croissant dans le domaine de la manipulation aérienne. La mise en œuvre de manipulateurs aériens dans l'industrie des UAV pourrait générer une augmentation significative du nombre d'applications possibles. Cependant, la restriction de la charge utile disponible est l’un des principaux inconvénients de cette approche. L'impossibilité d'équiper les drones de bras robotiques industriels puissants et habiles a suscité l'intérêt pour le développement de manipulateurs légers adaptés à ces applications. Dans le but de fournir une solution légère alternative aux manipulateurs aériens, cette thèse propose un bras robotique léger actionné par des fils en alliage à mémoire de forme (SMA). Bien que les fils SMA représentent une excellente alternative aux actionneurs conventionnels pour les applications légères, ils impliquent également une dynamique hautement non linéaire, ce qui les rend difficiles à contrôler. Cherchant à présenter une solution pour la tâche difficile de contrôler les fils SMA, ce travail étudie les conséquences et les avantages de la mise en œuvre des techniques de commande par retour d’état. L'objectif final de cette étude est la mise en œuvre expérimentale d'un contrôle à rétroaction d'état pour la régulation de la position du bras robotique léger proposé. Tout d'abord, un modèle mathématique basé sur un modèle physique du comportement des câbles SMA est développé et validé expérimentalement. Ce modèle décrit la dynamique du bras robotique léger proposé du point de vue de la mécatronique. Le bras robotique proposé est testé avec trois contrôleurs de retour de sortie pour le contrôle de position angulaire, à savoir un PID, un mode coulissant et une commande adaptative. Les contrôleurs sont testés dans une simulation MATLAB, puis mis en œuvre et testés expérimentalement selon différents scénarios. Ensuite, afin de réaliser la mise en œuvre expérimentale d’une technique de commande par retour d’état, un observateur d’état, à entrée inconnue, est développé. Premièrement, un modèle observable sans commutation avec une entrée inconnue est dérivé du modèle présenté précédemment. Ce modèle prend comme entrée inconnue le taux de fraction de martensite du modèle d'origine, ce qui permet d'éliminer les termes de commutation dans le modèle. Ensuite, un observateur, à entrées inconnues, basé sur le filtre de Kalman étendu et sur l’observateur à mode glissant est développé. Cet observateur permet l’estimation simultanée de l’état et des entrées inconnues. Les conditions suffisantes de convergence et de stabilité sont établies. L'observateur est testé dans une simulation MATLAB et validé expérimentalement dans différents scénarios. Enfin, une technique de commande par retour d’état est testée en simulation et implémentée de manière expérimentale pour le contrôle de position angulaire du bras robotique léger proposé. Elle est basée sur la résolution d’une équation de Riccati (SDRE). En conclusion, une analyse comparative quantitative et qualitative entre une approche de commande par retour de sortie et la une de commande par retour d’état mis en œuvre est effectuée selon plusieurs scénarios, y compris la régulation de position, le suivi de position et le suivi de charges utiles changeantesIn the last decade, the industry of Unmanned Aerial Vehicles (UAV) has gone through immense growth and diversification. Nowadays, we find drone based applications in a wide range of industries, such as infrastructure, agriculture, transport, among others. This phenomenon has generated an increasing interest in the field of aerial manipulation. The implementation of aerial manipulators in the UAV industry could generate a significant increase in possible applications. However, the restriction on available payload is one of the main setbacks of this approach. The impossibility to equip UAVs with heavy dexterous industrial robotic arms has driven the interest in the development of lightweight manipulators suitable for these applications. In the pursuit of providing an alternative lightweight solution for the aerial manipulators, this thesis proposes a lightweight robotic arm actuated by Shape Memory Alloy (SMA) wires. Although SMA wires represent a great alternative to conventional actuators for lightweight applications, they also imply highly nonlinear dynamics, which makes them difficult to control. Seeking to present a solution for the challenging task of controlling SMA wires, this work investigates the implications and advantages of the implementation of state feedback control techniques. The final aim of this study is the experimental implementation of a state feedback control for position regulation of the proposed lightweight robotic arm. Firstly, a mathematical model based on a constitutive model of the SMA wire is developed and experimentally validated. This model describes the dynamics of the proposed lightweight robotic arm from a mechatronics perspective. The proposed robotic arm is tested with three output feedback controllers for angular position control, namely a PID, a Sliding Mode and an Adaptive Controller. The controllers are tested in a MATLAB simulation and finally implemented and experimentally tested in various different scenarios. Following, in order to perform the experimental implementation of a state feedback control technique, a state and unknown input observer is developed. First, a non-switching observable model with unknown input of the proposed robotic arm is derived from the model previously presented. This model takes the martensite fraction rate of the original model as an unknown input, making it possible to eliminate the switching terms in the model. Then, a state and unknown input observer is proposed. This observer is based on the Extended Kalman Filter (EKF) for state estimation and sliding mode approach for unknown input estimation. Sufficient conditions for stability and convergence are established. The observer is tested in a MATLAB simulation and experimentally validated in various different scenarios. Finally, a state feedback control technique is tested in simulation and experimentally implemented for angular position control of the proposed lightweight robotic arm. Specifically, continuous and discrete-time State-Dependent Riccati Equation (SDRE) control laws are derived and implemented. To conclude, a quantitative and qualitative comparative analysis between an output feedback control approach and the implemented state feedback control is carried out under multiple scenarios, including position regulation, position tracking and tracking with changing payloads
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Lange, Dirk Klaus [Verfasser], and N. [Akademischer Betreuer] Bäuerle. "Cost optimal control of Piecewise Deterministic Markov Processes under partial observation / Dirk Klaus Lange ; Betreuer: N. Bäuerle." Karlsruhe : KIT-Bibliothek, 2017. http://d-nb.info/1132997739/34.
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Zhang, Lei. "Contribution to robust and adaptive control and observation of linear induction machine : High order sliding mode approach." Thesis, Bourgogne Franche-Comté, 2018. http://www.theses.fr/2018UBFCA010.
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Les effets d’extrémité jouent un rôle important dans la modélisation et la commande de la Machine Linéaire à Induction (MLI). Ces phénomènes augmentent significativement la non-linéarité du modèle de la machine et génèrent plusieurs difficultés pour contrôler et observer ses états avec de bonnes performances. Cette thèse aborde trois problématiques distinctes : la commande robuste de la MLI, l’estimation de la vitesse et du flux de la MLI et le contrôle robuste à base d’observateur en utilisant la théorie du mode glissant d’ordre supérieur.Dans la première partie de la thèse, trois contrôleurs robustes assurant la poursuite de trajectoire de la vitesse et du flux pour la MIL ont été développés : le Super Twisting (ST), le Super Twisting Adaptatif (STA) et le Twisting Adaptatif (TA). Ces commandes ont été testées en simulations et leurs performances ont été démontrées. Ainsi, le ST assure un contrôle continu avec convergence à temps fini de l’erreur à zéro malgré les perturbations, sous l’hypothèse que les bornes des incertitudes sont connues. Cette hypothèse est relaxée dans le cas du TA et du STA grâce à leurs propriétés adaptatives.Dans la deuxième partie de la thèse, un nouveau modèle du MLI a été proposé et son observabilité a été démontrée. Ensuite un Observateur par Mode Glissant d’Ordre Deux (MGOD) et un Observateur par Mode Glissant d’Ordre Supérieur (MGOS) ont été synthétisé afin d’estimer la vitesse et le flux du MLI, uniquement en utilisant la mesure des tensions et des courants statorique. La stabilité des deux observateurs a été prouvée par une approche de Lyapunov et leurs performances ont été démontrées à travers des simulations.Dans la dernière partie de la thèse, deux commandes par rejet actif des perturbations sont synthétisées. Ainsi et dans un premier temps, le modèle de la MLI est décomposé en deux sous-systèmes du second ordre. Ensuite, deux contrôleurs (le twisting et le super-twsiting) ont été synthétisés afin d’assurer la poursuite du flux et de la vitesse. Le MGOS est utilisé pour estimer les dérivées du flux et de la vitesse, ainsi que pour l’estimation en temps réel de la perturbation. Les contrôleurs quant à eux assurent la compensation des perturbations et la poursuite des trajectoires du flux et de la vitesse. La stabilité et la convergence des deux commandes proposées ont été prouvées et leurs performances démontrées par simulationDynamic end effects play an important role in the Linear Induction Machine (LIM) control. They increase significantly the nonlinearity of the machine model and generate several difficulties to control and observe states with good performances. This thesis addresses three distinctissues: LIM robust control, LIM speed and flux estimation and observer-based robust control using higher order sliding mode theory.In the first part, to achieve speed and flux tracking,Super Twisting Controller (STC), Adaptive Super Twisting Controller (ASTC), and Adaptive Twisting Controller (ATC) were proposed and implemented into LIM system with great performance, i.e. finite time convergence and robustness properties. Among them, STC ensures continuous control with finite time convergence of the error to zero despite disturbances, under the assumption that their bounds are known. ATC and ASTC can deal with unknown bounded disturbance thanks to their adaptive properties.In the second part, a novel simplified LIM model was proposed and its observability has been proved. Then, Second Order Sliding Mode Observer (SOSMO) and Adaptive High Order Sliding Mode Observer (HOSMO) were proposed to estimate LIM speed, only by using the measured stator voltages and stator currents. SOSMO observer is based on the super twisting algorithm and its stability has been proved with Lyapunov’s theory, which can guarantee finite time convergence with less chattering. Adaptive HOSMO strategy combines speed adaptive algorithm and HOSMO method together to estimate rotor fluxes and speed simultaneously.In the third part, the LIM is viewed as two second order subsystems. Moreover, only the speed and the flux are supposed to be measured. Based on that two differentcontrollers based on HOSMO were presented in order to achieve flux and speed tracking. In both controllers, the idea of active disturbance rejection control is applied. Hence, the HOSMO is used to estimate the derivatives of the flux and the speed, as well as the disturbance. Then, in order to deal with the uncertainty in the measured variables, two different SM controllers are proposed. Firstly, the TC is applied in the LIM. However, the control signal in this case is discontinuous. Then, in order to provide a continuous control signal, the TC is replaced with STC. The stability and convergence of proposed TC-HOSMO and STC-HOSMO approaches were given and simulation validated their performances
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Persiaux, François Christophe. "Le contrôle des projets d'innovation de haute technologie : une contribution à la théorie élaborée à partir de cas observés de façon longitudinale à France Telecom." Jouy-en Josas, HEC, 2005. http://www.theses.fr/2005EHEC0001.
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Faire converger les fonctions d’innovation et de contrôle de gestion repose a priori sur une antinomie, bien que certaines recherches montrent que leurs interactions peuvent être productives. L’innovation de haute technologie est au cœur de cette problématique. L’objet de cette recherche est alors d’étudier de manière empirique les outils et mécanismes pertinents pour piloter la gestion d’un projet d’innovation de haute technologie (PIHT). Cette recherche passe d’abord par l’analyse systématique des modes de contrôle de ces projets. Elle s’appuie ensuite sur une expérience en « observation participante » : cette méthodologie permet d’enrichir l’analyse des modes de contrôle de PIHT par des observations faites dans France Telecom, une entreprise où ces enjeux sont stratégiques. En observant l’avancement de plusieurs projets de façon longitudinale, la recherche débouche sur la proposition de critères de performance pour le contrôle des PIHT, complétant par conséquent les méthodologies des sciences de gestion consacrées à l’innovationAs far as management control and innovation are concerned, some researchers think it is worth studying their convergence. High technology innovation has proved to be at the core of this problem. Our research project aims therefore at conducting an empirical study of the relevant methods for controlling a High Technology Innovation Project (HTIP). This research project begins with a systematic analysis of the various modes of control for these projects. It is also based on a “participant observer” approach: thanks to observations in France Telecom – a company for whom these strategic stakes are important – this method helps enriching the conceptual framework of these modes of control. The observation of various projects in time enables us to eventually propose HTIP control performance criteria, thus broadening the knowledge of innovation
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Janse, van Vuuren Gerhard Hermann. "The design and simulation analysis of an attitude determination and control system for a small earth observation satellite." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96979.
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Thesis (MEng)--Stellenbosch University, 2015.ENGLISH ABSTRACT: The ability of satellites to actively control their attitude has changed the way we live. Navigation systems, satellite television, and weather forecasting, for example, all rely on satellites which are able to determine and control their attitude accurately. This project was aimed at designing and analysing an attitude determination and control system (ADCS) for a 20 kg Earth observation satellite by means of simulation. A realistic simulation toolset, which includes the space environment, sensor, and actuator models, was created using MATLAB and Simulink. An ADCS hardware suite was selected for the satellite based on a given set of pointing and stability requirements, as well as current trends in the small satellite industry. The hardware suite consists of among others a star tracker and three reaction wheels. A variety of estimators and controllers were investigated, after which an application specific ADCS state machine was defined. The state machine included a Safe Mode for de-tumbling, a Nominal Mode for normal operation, a Forward Motion Compensation (FMC) Imaging Mode for Earth observation, and a Target Tracking Mode for ground station tracking. Simulation results indicated that de-tumbling, coarse and fine sun tracking, FMC factor 4 imaging, and target tracking were successfully implemented. Lastly, the satellite’s pointing error and stability were determined to be less than 70 arcseconds and 7 arcseconds per second respectively, both values well within the given requirements.
AFRIKAANSE OPSOMMING: Satelliete se vermoë om hul oriëntasie aktief te beheer, het die manier waarop ons lewe, verander. Navigasiestelsels, satelliettelevisie en weervoorspelling, byvoorbeeld, maak staat op satelliete wat hul oriëntasie akkuraat kan bepaal en beheer. Die mikpunt van hierdie projek was die ontwerp en analise van ’n oriëntasiebepaling- en -beheerstelsel (ADCS) vir ’n 20 kg aardwaarnemingsatelliet deur middel van simulasie. ’n Realistiese simulasieopstelling, wat modelle van die ruimteomgewing, sensore en aktueerders insluit, was ontwikkel deur gebruik te maak van MATLAB en Simulink. ’n ADCS hardewarestel was gekies vir die satelliet op grond van ’n stel rig- en stabiliteitsvereistes, sowel as die huidige tendense in die klein-satellietbedryf. Die hardewarestel bestaan onder andere uit ’n stervolger en drie reaksiewiele. Nadat verskeie afskatters en beheerders ondersoek was, was ’n toepassingspesifieke ADCS toestandmasjien gedefinieer. Die toestandmasjien het ’n Veilige Modus vir onttuimelling, ’n Nominale Modus vir normale operasie, ’n Vorentoe-bewegingskompensering (FMC) Beeldskandeermodus vir aardwaarneming en ’n Teikenvolgmodus vir grondstasie volging ingesluit. Simulasieresultate het aangedui dat onttuimeling, growwe- en fyn sonvolging, FMC faktor 4 beeldskandering en teikenvolging suksesvol geïmplementeer was. Laastens was die satelliet se rigfout en stabiliteit bepaal as minder as 70 boogsekondes en 7 boogsekondes per sekonde onderskeidelik, albei waardes gemaklik binne die vereistes.
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Qin, Jinna. "Commande hybride position/force robuste d’un robot manipulateur utilisé en usinageet/ou en soudage." Thesis, Paris, ENSAM, 2013. http://www.theses.fr/2013ENAM0058/document.
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La problématique traitée dans cette thèse concerne la commande de robots manipulateurs industriels légèrement flexibles utilisés pour la robotisation de procédés d'usinage et de soudage FSW. Le premier objectif est la modélisation des robots et des procédés. Les modèles développés concernant la cinématique et la dynamique de robots 6 axes à architecture série et à flexibilité localisées aux articulations. Les paramètres du modèle dynamique et les raideurs sont identifiés avec la méthode à erreur de sortie qui donne une bonne précision d'estimation. La norme relative du résidu du modèle après identification est de 3,2%. Le deuxième objectif est l'amélioration des performances de la robotisation des procédés. Un simulateur a été développé qui intègre le modèle dynamique du robot flexible, les modèles de procédés et le modèle du contrôleur de robot y compris les lois de commande en temps réel des axes et le générateur de trajectoires. Un observateur non-linéaire à grands gains est proposé pour estimer l'état complet du robot flexible ainsi que les efforts d'interaction. Ensuite, un compensateur basé sur l'observateur est proposé pour corriger les erreurs de positionnement en temps réel. La validation expérimentale sur un robot industriel Kuka, montre une très bonne estimation de l'état complet par l'observateur. Un soudage FSW précis grâce à la compensation en temps réel de la flexibilité du manipulateur a pu être effectué avec succèsThe problem addressed in this thesis concerns the control of industrial robot manipulators which are slightly flexible and used for machining and FSW processes. The first objective is to model the robots and processes. The developed models concern the kinematics and dynamics models of 6-axis robots with serial architecture and flexibility localized at joints. The dynamic model parameters and a part of the joint stiffnesses are identified with the approach of output error which gives a satisfy estimation accuracy. According to identification, the RMS residue of the model is 3.2%. The second objective is to improve the robotization performance of manufacturing processes. A simulator was developed that contains the dynamic model of the flexible robot, the process models and the model of the robot controller including control laws in real time of axes and the trajectory generator. A nonlinear high-gains observer is proposed to estimate the complete states of robot system as well as the operation wrenches. Then the observer-based compensator is proposed to correct the positioning errors in real time. The experimental validation of industrial robots shows a satisfactory estimating performance of the observer. A precise FSW welding owing to the real-time compensation for the flexibility of manipulator has been done successfully
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RINALDI, GIANMARIO. "Local and Wide-Area Sliding Mode State Observation, Fault Reconstruction and Control with Application to Modern Power Systems." Doctoral thesis, Università degli studi di Pavia, 2020. http://hdl.handle.net/11571/1326211.
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The present thesis summarises the research activity carried our by the PhD candidate Gianmario
Rinaldi from October 2016 to September 2019 at the Department of Electrical, Computer and Biomedical
Engineering at the University of Pavia, Italy.
In recent years, radical changes are taking place to power systems. A worldwide consensus has
been reached for the reduction of greenhouse effects, by promoting the growth of renewable energy
sources in power grids. Therefore, a special shared interest has been raised amongst researchers and
practitioners to turn the existing power grids into smarter and more reliable ones, which are able to
safely, efficiently, an reliably integrate the growing renewable energy sources.
Supervisory Control And Data Acquisition (SCADA) has been the conventional control and state
estimation methodology practically used in the last few decades. Recent progress in computer science
and electronic technologies has opened the door to the implementation of the so-called Wide Area
Measurement Systems (WAMS). In particular, with a widespread deployment of Phasor Measurement
Units (PMUs), a more accurate depiction of the state in power systems has become achievable
in practice.
Latest advances in computer science and electronic technologies have laid the groundwork for
the conception of the so-called cyber-attacks, which can be defined as computer-based algorithms
capable of destabilising the power network by compromising the collected measurements to be sent
to a control centre, attack the communication networks, or alter and delay the control variables.
In order to turn the existing power system into a smarter one capable of both harmoniously
integrating renewable power sources and efficiently and safely dealing with faults and cyber-attacks,
the attention is now focused on the following relevant research areas:
The design and assessment of more accurate, robust and dynamic state estimators in power systems,
which are able to obtain a near-real time depiction of all the state variables, instrumental
in enhancing the monitoring of the networks.
The implementation of timely fault detection, reconstruction and mitigation methodologies,
devoted to preserve the stability of the entire power network, thus preventing wide-spread
outages, blackouts, and degradations of the power quality.
The design of identification schemes to determine key-properties of the components in power
system context.
The design and assessment of novel control approaches devoted to both regulate the frequency
deviations and minimise the cost of the power generation. These control schemes are also required to be robust to possible faults, disturbances, and uncertainties affecting the power
systems.
The present thesis aims to fit into the aforementioned promising research areas in power systems. In
particular, four challenges are addressed:
The first addressed challenge considers the design of robust state estimators which are able to
depict in near real time the state of the overall power systems to globally enhance the monitoring
of the power systems, thus reducing the number of the deployed sensors. The undertaken
analysis started at the local level and then consider the power system as a large-scale system.
The second addressed challenge focuses on the design of fault detection, reconstruction, and
mitigation approaches devoted to enhance the resilience of the power network.
The third addressed challenge considers the design and the assessment of robust sliding mode
observer-based controllers which are capable of regulating the frequencies in power systems
whilst minimising the cost associated with the generators.
Finally, the fourth addressed challenges examines the identification of the relative degree properties
with application to electrical and power systems frameworks.
Furthermore, the outline of the present thesis is coherent with the development of the contributions
illustrated above.
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Theil, Stephan [Verfasser]. "Satellite and Test Mass Dynamics Modeling and Observation for Drag-free Satellite Control of the STEP Mission / Stephan Theil." Aachen : Shaker, 2003. http://d-nb.info/1179033310/34.
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Fraser, Brent DeWayne. "Development of a Methodology for Assessing Military Team Processes." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/35082.
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This study is based upon the premise that overall team performance is the sum of the team's performance in several individual team processes. The purpose of this study was to develop a tool to measure performance in each of these individual team processes. This study begins the measurement development cycle by developing a tool that uses direct observation to collect data on team processes. The tool was then tested in a battle simulation being used as a C2 training exercise. The study showed that (1) the team process performance can be measured using direct observation, and (2) non subject-matter experts can accurately and reliably rate team performance by using the data collection tool.
The tool developed here relied on an observer to rate the command team on 43 items concerning ten team processes. Ratings were collected on visual analog scales that were overlaid with a Likert-type template for analysis. The results showed that six of the ten constructs were measured reliably and validly. However, inter-rate reliability was shown to be an issue to be overcome in future studies. The implications of this weakness, the potential of this line of research,and potential tool design changes are discussed in this thesis.Master of Science
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Boukal, Yassine. "Observation et commande des systèmes dynamiques d’ordre non entier." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0154/document.
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Ce travail de thèse concerne la synthèse des observateurs et des lois de commande des systèmes d’ordre fractionnaire. Le document présenté est constitué de 4 chapitres : Le premier chapitre du manuscrit de thèse contient une introduction, traitant les notions mathématiques de base et de stabilités des systèmes d’ordre fractionnaire ainsi qu’une présentation des différentes définitions. Les conditions de stabilités de ces systèmes et quelques exemples de systèmes modélisés par des équations différentielles fractionnaires sont présentés. Dans le deuxième chapitre, nous nous sommes intéressés à la conception de plusieurs types d’observateurs dits d’ordre réduit, d’ordre plein et des observateurs fonctionnels pour les systèmes d’ordre fractionnaire avec et sans retards. Dans le cas où il n’y a pas de retards dans la dynamique du système, des observateurs d’ordres plein et réduit ont été synthétisé afin d’assurer l’estimation des pseudo-états. Dans un deuxième temps, un observateur fonctionnel a été synthétisé dans le cas où le retard est présent dans la dynamique du système. Dans le chapitre 3, nous avons travaillé sur la synthèse d’observateur pour les systèmes d’ordre fractionnaire incertains. Nos contributions sont classées en trois grandes lignes : premièrement, quand le système considéré est affecté par des entrées inconnues, un observateur fonctionnel a été proposé. En deuxième partie, des observateurs H∞ pour les systèmes d’ordre fractionnaire avec et sans retards ont été synthétisés afin d’assurer la stabilité de l’erreur d’observation. Il s’agit en fait de garantir une borne du gain L2 entre l’erreur d’observation et les perturbations non mesurables affectant la dynamique du système : ce gain L2 est aussi appelé norme H∞. Ce chapitre présente aussi la synthèse d’un observateur robuste vis-à-vis des incertitudes de modélisation pour cette classe de systèmes. Les conditions suffisantes de convergence des erreurs d’estimations des pseudo-états obtenues sont établies sous la forme d’un ensemble d’inégalités matricielles LMIs. Le dernier chapitre du manuscrit est consacré à la commande basée sur les différents observateurs obtenus. Nous nous sommes intéressés à la commande basée sur un observateur pour les systèmes d’ordre fractionnaire. Cette commande est basée sur les observateurs proposés dans les chapitres précédents. Des conditions de stabilité et des procédures de synthèse sont présentéesThis work focuses on the synthesis of observers and the controller laws for fractional order systems. The presented document consists of 4 chapters: The first chapter of the theses manuscript contains an introduction dealing with the basic mathematical notions and the stability analysis of fractional systems as well as a presentation of the different definitions. The stability conditions of these systems and some examples of systems modeled by fractional differential equations are presented. In the second chapter, we were interested in the design of several types of observers of reduced order, full order, and functional observers for fractional systems with and without delays. In the case where there are no delays in the dynamics of the system, observers of full and reduced orders have been synthesized in order to ensure the estimation of the pseudo-states. In a second step, a functional observer was synthesized in the case where the delay is present in the dynamics of the system. In Chapter 3, we worked on observer synthesis for uncertain fractional order systems. Our contributions are classified into three main lines: first, when the system under consideration is affected by unknown inputs, a functional observer has been proposed. In the second part, H∞ observers for fractional order systems with and without delays have been synthesized to ensure the stability of the estimation error. It is a question of guaranteeing a bound of the L2 gain between the observation error and the non-measurable perturbations affecting the dynamics of the system: this gain L2 is also called H∞ norm. In last part of this chapter, the synthesis of a robust observer with respect to modeling uncertainties for this class of systems is presented. The sufficient conditions of convergence of the estimation errors of the pseudo-states obtained are established in the form of a set of matrix inequalities LMIs. The last chapter of the manuscript is devoted to the command based on the different observers obtained. We were interested in observer-based control for fractional order systems. This command is based on the observers proposed in the previous chapters. Stability conditions and synthesis procedures are presented
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Biggs, Jason Daniel 1978. "Theoretical studies of the external vibrational control of electronic excitation transfer and its observation using polarization- and optical phase-sensitive ultrafast spectroscopy." Thesis, University of Oregon, 2010. http://hdl.handle.net/1794/11074.
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xvi, 218 p. : ill. (some col.)Our theoretical studies involve the control of electronic energy transfer in molecular dimers through the preparation of specific vibrational coherences prior to electronic excitation. Our control strategy is based upon the fact that, following impulsive electronic excitation, nuclear motion acts to change the instantaneous energy difference between site-excited electronic states and thereby influences short-time electronic excitation transfer (EET). By inducing coherent intramolecular vibration in one of the chromophores prior to short-pulse electronic excitation, we exert external control over electronic dynamics. As a means to monitor this coherent control over EET, we propose using multidimensional wave-packet interferometry (md-WPI). Two pairs of polarized phase-related femtosecond pulses following the control pulse would generate superpositions of coherent nuclear wave packets in optically accessible electronic states. Interference contributions to the time- and frequency-integrated fluorescence signal due to overlaps among the superposed wave packets provide amplitude-level information on the nuclear and electronic dynamics. We test both the control strategy and its spectroscopic investigation by calculating pump-probe difference signals for various combinations of pulse polarizations. That signal is the limiting case of the control-influenced md-WPI signal in which the two pulses in the pump pulse-pair coincide, as do the two pulses in the probe pulse-pair. We present calculated pump-probe difference signals for a variety of systems including a simplified model of the covalent dimer dithia-anthracenophane (DTA) in which we treat only the weakly Franck-Condon active ν 12 anthracene vibration at 385 cm -1 . We further present calculated nl-WPI difference signals for an oriented DTA complex, which reveal amplitude-level dynamical information about the interaction of nuclear motion and electronic energy transfer. We also present pump-probe difference signals from a model system in which a CF 3 group, whose torsional angle is strongly Franck-Condon active, has been added to the anthracene monomers which make up DTA. We make use of electronic structure calculations to find the torsional potential of the monomer, from which we calculate the spectroscopic signals of the dimer. We show that a significant measure of control over short-time EET is achievable in this system. This dissertation includes previously published coauthored material.
Commitee in charge: Dr. Michael E. Kellman, Chair; Dr. Jeffrey A. Cina, Advisor; Dr. David R. Herrick; Dr. Andrew H. Marcus; Dr. Daniel A. Steck