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Sun, Xiaoyu. "Unknown input observer approaches to robust fault diagnosis." Thesis, University of Hull, 2013. http://hydra.hull.ac.uk/resources/hull:8021.
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This thesis focuses on the development of the model-based fault detection and isolation /fault detection and diagnosis (FDI/FDD) techniques using the unknown input observer (UIO) methodology. Using the UI de-coupling philosophy to tackle the robustness issue, a set of novel fault estimation (FE)-oriented UIO approaches are developed based on the classical residual generation-oriented UIO approach considering the time derivative characteristics of various faults. The main developments proposed are: - Implement the residual-based UIO design on a high fidelity commercial aircraft benchmark model to detect and isolate the elevator sensor runaway fault. The FDI design performance is validated using a functional engineering simulation (FES) system environment provided through the activity of an EU FP7 project Advanced Fault Diagnosis for Safer Flight Guidance and Control (ADDSAFE). - Propose a linear time-invariant (LTI) model-based robust fast adaptive fault estimator (RFAFE) with UI de-coupling to estimate the aircraft elevator oscillatory faults considered as actuator faults. - Propose a UI-proportional integral observer (UI-PIO) to estimate actuator multiplicative faults based on an LTI model with UI de-coupling and with added H∞ optimisation to reduce the effects of the sensor noise. This is applied to an example on a hydraulic leakage fault (multiplicative fault) in a wind turbine pitch actuator system, assuming that thefirst derivative of the fault is zero. - Develop an UI–proportional multiple integral observer (UI-PMIO) to estimate the system states and faults simultaneously with the UI acting on the system states. The UI-PMIO leads to a relaxed condition of requiring that the first time derivative of the fault is zero instead of requiring that the finite time fault derivative is zero or bounded. - Propose a novel actuator fault and state estimation methodology, the UI–proportional multiple integral and derivative observer (UI-PMIDO), inspired by both of the RFAFE and UI-PMIO designs. This leads to an observer with the comprehensive feature of estimating faults with bounded finite time derivatives and ensuring fast FE tracking response. - Extend the UI-PMIDO theory based on LTI modelling to a linear parameter varying (LPV) model approach for FE design. A nonlinear two-link manipulator example is used to illustrate the power of this method.
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Cambron, Daniel. "A Lithium Battery Current Estimation Technique Using an Unknown Input Observer." UKnowledge, 2016. http://uknowledge.uky.edu/ece_etds/84.
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Current consumption measurements are useful in a wide variety of applications, including power monitoring and fault detection within a lithium battery management system (BMS). This measurement is typically taken using either a shunt resistor or a Hall-effect current transducer. Although both methods have achieved accurate current measurements, shunt resistors have inherent power loss and often require isolation circuitry, and Hall-effect sensors are generally expensive. This work explores a novel alternative to sensing battery current by measuring terminal voltages and cell temperatures and using an unknown input observer (UIO) to estimate the battery current. An accurate model of a LiFePO4 cell is created and is then used to characterize a model of the proposed current estimation technique. Finally, the current estimation technique is implemented in hardware and tested in an online BMS environment. Results show that the current estimation technique is sufficiently accurate for a variety of applications including fault detection and power profiling.
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PEDONE, Salvatore. "Robust Control of Nonlinear Systems: An Unknown Input Observer Based Approach." Doctoral thesis, Università degli Studi di Palermo, 2023. https://hdl.handle.net/10447/580735.
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Questa tesi propone un controllore robusto per sistemi non lineari tramite l'utilizzo di un osservatore ad ingressi sconosciuti. Attraverso un'opportuna riformulazione dinamica del modello,
un generico sistema non lineare viene descritto come la somma di due funzioni, la prima lineare e nota
e la seconda altamente non lineare e sconosciuta, derivante dalla conoscenza imperfetta del modello dinamico, dei parametri, o di eventuali disturbi esogeni agenti sul sistema etc., modellabili come perturbazioni (disturbi) della funzione lineare. Questa semplificazione consente una vantaggiosa descrizione dinamica del sistema in
forma matriciale. Le informazioni necessarie sono stimate attraverso l'utilizzo di un osservatore ad ingressi sconosciuti a tempo discreto in grado di stimare asintoticamente sia lo stato del sistema che il disturbo al solo costo di qualche ritardo campionario. Infine, è realizzato un controllore che attivamente compensa il disturbo stimato e forza asintoticamente lo stato del sistema a quello desiderato. La tesi presenta inoltre la prova di stabilità in anello chiuso del metodo proposto. La soluzione proposta non necessita di informazioni a priori sulle dimensioni del disturbo, variabili aggiuntive per modellare le incertezze o parametri dell'osservatore da regolare. L' efficacia e la superiorità rispetto ai metodi esistenti è validata in teoria e in pratica in due modi diversi contesti: auto da corsa a guida autonoma e soft-robot articolati.This thesis addresses the robust control of complex nonlinear system via an Unknown Input Observer based approach. More specifically, through a suitable model dynamic reformulation, a generic nonlinear system has been described as the sum of two functions, the first linear and known and the second highly nonlinear and unknown, resulting from imperfect knowledge of system model parameters, exogenous disturbances and so on, which can be seen as a perturbation (disturbance) of the linear function. This simplification allows an advantageous system dynamic description in matrix form. Subsequently, a discrete-time Delayed Unknown Input Observer has been designed to asymptotically estimate both system state and disturbance at the only cost of a few sample delay. Finally, a controller actively compensates the estimated disturbance and asymptotically steers the system state to the desired one. This thesis also presents a closed-loop stability proof of the method. The proposed solution advantageously needs no a-priori information about the total perturbation boundedness, additional variables to model uncertainties, or observer parameters to be tuned. Its effectiveness and superiority to existing methods are studied in theory and practice in two different contexts, i.e. self-driving racecars and articulated soft-robots.
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Yang, Hanlong. "Estimation and fault diagnostics in nonlinear and time delay systems based on unknown input observer methodology." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq24368.pdf.
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Lyubchyk, Leonid, and Galina Grinberg. "Inverse Dynamic Models in Chaotic Systems Identification and Control Problems." Thesis, Ternopil National Economic University, 2018. http://repository.kpi.kharkov.ua/handle/KhPI-Press/36824.
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Inverse dynamic models approach for chaotic system synchronization in the presence of uncertain parameters is considered. The problem is identifying and compensating unknown state-dependent parametric disturbance describing an unmodelled dynamics that generates chaotic motion. Based on the method of inverse model control, disturbance observers and compensators are synthesized. A control law is proposed that ensures the stabilization of chaotic system movement along master reference trajectory. The results of computational simulation of controlled Rösller attractor synchronization are also presented.
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Heydari, Mahdi. "Adaptive distributed observers for a class of linear dynamical systems." Digital WPI, 2015. https://digitalcommons.wpi.edu/etd-dissertations/227.
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The problem of distributed state estimation over a sensor network in which a set of nodes collaboratively estimates the state of continuous-time linear systems is considered. Distributed estimation strategies improve estimation and robustness of the sensors to environmental obstacles and sensor failures in a sensor network. In particular, this dissertation focuses on the benefits of weight adaptation of the interconnection gains in distributed Kalman filters, distributed unknown input observers, and distributed functional observers. To this end, an adaptation strategy is proposed with the adaptive laws derived via a Lyapunov-redesign approach. The justification for the gain adaptation stems from a desire to adapt the pairwise difference of estimates as a function of their agreement, thereby enforcing an interconnection-dependent gain. In the proposed scheme, an adaptive gain for each pairwise difference of the interconnection terms is used in order to address edge-dependent differences in the estimates. Accounting for node-specific differences, a special case of the scheme is presented where it uses a single adaptive gain in each node estimate and which uniformly penalizes all pairwise differences of estimates in the interconnection term. In the case of distributed Kalman filters, the filter gains can be designed either by standard Kalman or Luenberger observers to construct the adaptive distributed Kalman filter or adaptive distributed Luenberger observer. Stability of the schemes has been shown and it is independent of the graph topology and therefore the schemes are applicable to both directed and undirected graphs. The proposed algorithms offer a significant reduction in communication costs associated with information flow by the nodes compared to other distributed Kalman filters. Finally, numerical studies are presented to illustrate the performance and effectiveness of the proposed adaptive distributed Kalman filters, adaptive distributed unknown input observers, and adaptive distributed functional observers.
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Xiong, Yi. "Robust fault diagnosis in linear and nonlinear systems based on unknown input, and sliding mode functional observer methodologies." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ61696.pdf.
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Su, Jinya. "Fault estimation algorithms : design and verification." Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/23231.
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The research in this thesis is undertaken by observing that modern systems are becoming more and more complex and safety-critical due to the increasing requirements on system smartness and autonomy, and as a result health monitoring system needs to be developed to meet the requirements on system safety and reliability. The state-of-the-art approaches to monitoring system status are model based Fault Diagnosis (FD) systems, which can fuse the advantages of system physical modelling and sensors' characteristics. A number of model based FD approaches have been proposed. The conventional residual based approaches by monitoring system output estimation errors, however, may have certain limitations such as complex diagnosis logic for fault isolation, less sensitiveness to system faults and high computation load. More importantly, little attention has been paid to the problem of fault diagnosis system verification which answers the question that under what condition (i.e., level of uncertainties) a fault diagnosis system is valid. To this end, this thesis investigates the design and verification of fault diagnosis algorithms. It first highlights the differences between two popular FD approaches (i.e., residual based and fault estimation based) through a case study. On this basis, a set of uncertainty estimation algorithms are proposed to generate fault estimates according to different specifications after interpreting the FD problem as an uncertainty estimation problem. Then FD algorithm verification and threshold selection are investigated considering that there are always some mismatches between the real plant and the mathematical model used for FD observer design. Reachability analysis is drawn to evaluate the effect of uncertainties and faults such that it can be quantitatively verified under what condition a FD algorithm is valid. First the proposed fault estimation algorithms in this thesis, on the one hand, extend the existing approaches by pooling the available prior information such that performance can be enhanced, and on the other hand relax the existence condition and reduce the computation load by exploiting the reduced order observer structure. Second, the proposed framework for fault diagnosis system verification bridges the gap between academia and industry since on the one hand a given FD algorithm can be verified under what condition it is effective, and on the other hand different FD algorithms can be compared and selected for different application scenarios. It should be highlighted that although the algorithm design and verification are for fault diagnosis systems, they can also be applied for other systems such as disturbance rejection control system among many others.
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Schaal, Peter. "Observer-based engine air charge characterisation : rapid, observer-assisted engine air charge characterisation using a dynamic dual-ramp testing method." Thesis, Loughborough University, 2018. https://dspace.lboro.ac.uk/2134/33247.
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Characterisation of modern complex powertrains is a time consuming and expensive process. Little effort has been made to improve the efficiency of testing methodologies used to obtain data for this purpose. Steady-state engine testing is still regarded as the golden standard, where approximately 90% of testing time is wasted waiting for the engine to stabilize. Rapid dynamic engine testing, as a replacement for the conventional steady-state method, has the potential to significantly reduce the time required for characterisation. However, even by using state of the art measurement equipment, dynamic engine testing introduces the problem that certain variables are not directly measurable due to the excitation of the system dynamics. Consequently, it is necessary to develop methods that allow the observation of not directly measurable quantities during transient engine testing. Engine testing for the characterisation of the engine air-path is specifically affected by this problem since the air mass flow entering the cylinder is not directly measurable by any sensor during transient operation. This dissertation presents a comprehensive methodology for engine air charge characterisation using dynamic test data. An observer is developed, which allows observation of the actual air mass flow into the engine during transient operation. The observer is integrated into a dual-ramp testing procedure, which allows the elimination of unaccounted dynamic effects by averaging over the resulting hysteresis. A simulation study on a 1-D gas dynamic engine model investigates the accuracy of the developed methodology. The simulation results show a trade-off between time saving and accuracy. Experimental test result confirm a time saving of 95% compared to conventional steady-state testing and at least 65% compared to quasi steady-state testing while maintaining the accuracy and repeatability of conventional steady-state testing.
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TRUMIC, Maja. "STIFFNESS ESTIMATION AND ADAPTIVE CONTROL FOR SOFT ROBOTS." Doctoral thesis, Università degli Studi di Palermo, 2021. http://hdl.handle.net/10447/509120.
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Nonostante la sorprendente crescita nello sviluppo dei robot ispirati alla natura, tra cui i cosiddetti soft robot, il potenziale di questi sistemi, che hanno intrinseche capacità di adattamento, non è ancora stato sfruttato a pieno. La ricerca ha principalmente considerato il controllo in retroazione della posizione dei giunti del robot, lasciando la gestione della cedevolezza di questi ultimi ancora in anello aperto. Peraltro, le attuali limitazioni nel processo di produzione degli attuatori a cedevolezza variabile e l'inevitabile variabilità nel tempo degli elementi elastici costitutivi, i quali sono soggetti ad usura e deformazione plastica, rendono il problema della determinazione precisa della rigidezza di giunto ancora oggi una sfida.
In tale ambito, questa tesi pone l'accento sulla stima della rigidezza e sul controllo adattativo dei soft robot, considerando in primis i sistemi articolati e pilotati da attuatori a cedevolezza variabile (VSA) in configurazione antagonista. Ciò viene fatto con l'obiettivo primario di imporre simultaneamente una dinamica desiderata sia per la posizione che per la rigidezza e, conseguentemente, di migliorare la sicurezza fisica e le prestazioni di un soft robot.
Basandosi sulla teoria degli osservatori ad ingresso sconosciuto (UIO), in questo lavoro vengono proposte soluzioni, invasive e non, che consentono di stimare la rigidezza nei robot con attuatori pneumatici o elettromeccanici, soluzioni che nel secondo caso vengono anche validate sperimentalmente. Oltre al vantaggio della linearità e della scalabilità, le suddette soluzioni hanno l'interessante caratteristica di non richiedere l'uso di sensori di coppia o velocità.
Sfruttando così la disponibilità di una stima della rigidezza, il lavoro descrive inoltre dei metodi innovativi per il controllo robusto dei soft robot articolati, il cui schema include un compensatore adattativo e un disaccoppiatore dinamico. Detti metodi possono gestire le incertezze nella conoscenza del modello dinamico del robot e, quando il riferimento della rigidezza è costante o lentamente variabile, anche quelle relative all'attuatore pneumatico. La loro verifica è valutata attraverso delle simulazioni e, nel caso pneumatico, anche per via sperimentale.
Infine, la tesi mostra come estendere le tecniche di controllo adattativo ai sistemi robotici con cedevolezza distribuita lungo l'intero corpo del robot, garantendo formalmente la convergenza del controllore. L'efficacia di questa tecnica adattativa è mostrata attraverso una estensiva simulazione.Although there has been an astonishing increase in the development of nature-inspired robots equipped with compliant features, i.e. soft robots, their full potential has not been exploited yet. One aspect is that the soft robotics research has mainly focused on their position control only, while stiffness is managed in open loop. Moreover, due to the difficulties of achieving consistent production of the actuation systems for soft articulated robots and the time-varying nature of their internal flexible elements, which are subject to plastic deformation over time, it is currently a challenge to precisely determine the joint stiffness. In this regard, the thesis puts an emphasis on stiffness estimation and adaptive control for soft articulated robots driven by antagonistic Variable Stiffness Actuators (VSAs) with the aim to impose the desired dynamics of both position and stiffness, which would finally contribute to the overall safety and improved performance of a soft robot. By building upon Unknown Input Observer (UIO) theory, invasive and non-invasive solutions for estimation of stiffness in pneumatic and electro-mechanical actuators are proposed and in the latter case also experimentally validated. Beyond the linearity and scalability advantage, the approaches have an appealing feature that torque and velocity sensors are not needed. Once the stiffness is determined, innovative control approaches are introduced for soft articulated robots comprising an adaptive compensator and a dynamic decoupler. The solutions are able to cope with uncertainties of the robot dynamic model and, when the desired stiffness is constant or slowly-varying, also of the pneumatic actuator. Their verification is performed via simulations and then the pneumatic one is successfully tested on an experimental setup. Finally, the thesis shows via extensive simulations the effectiveness of adaptive technique applied to soft-bodied robots, previously deriving the sufficient and necessary conditions for the controller convergence.
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Aguiar, Cota Braulio Norberto. "Pilotage automatique robuste de train sous contrainte d'enrayage-patinage." Thesis, Valenciennes, 2019. http://www.theses.fr/2019VALE0022.
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Des millions de personnes utilisent le train chaque jour. Par conséquent, l’efficacité et la sécurité du transport ferroviaire et de l’infrastructure sont essentielles pour les clients et les entreprises. De nos jours, l’un des principaux défis est d’augmenter le niveau d’automatisation des trains, du niveau d’automatisation « 0 » (ou Goals of Automation GoA) qui consiste essentiellement à exploiter les trains à vue jusqu’au niveau « 4 », où les opérations ne sont pas surveillées. Les niveaux GoA sont définis par l’Union internationale des transports publics (UITP) et ont pour objectif de fournir une feuille de route pour le développement et l’intégration des systèmes dits « d’exploitation automatique des trains » ou ATO. Les ATO sont des dispositifs d’amélioration de la sécurité opérationnelle qui aident le conducteur en automatisant certaines opérations, lui permettant de se concentrer sur les problèmes de sécurité éventuels ou les situations imprévues. Actuellement, le niveau d’automatisation atteint pour le matériel roulant commercial est GoA « 2 », ou une exploitation semi-automatique des trains, les opérations de démarrage et d’arrêt étant automatisées. La plupart des systèmes ATO existants sont GoA 2. Comme dans tout véhicule moderne, les systèmes embarqués sur un train sont liés et l’ATO collabore avec les organes de sécurité tels que la protection automatique des trains (ATP) et la surveillance automatique des trains (ATS). Il doit garantir le respect des limitations de vitesse et arrêter le train à la gare avec précision, tout en respectant une table horaire. La tâche d’arrêt est effectuée par le contrôle automatique de l’arrêt des trains (ATSC). L’ensemble de ces dispositifs forment le contrôle automatique des trains (ATC) (Dong et al. 2010). Tous les systèmes automatiques reposent sur deux fonctions principales : la perception et la décision. Le dispositif ATO s’appuiera fortement sur les informations disponibles pour assurer une perception précise de son environnement et de la situation opérationnelle, afin de prendre les bonnes décisions. Ces informations sont acquises par des capteurs de différentes technologies et mises à disposition via le réseau de communication (bus) du train. De toute évidence, les capteurs sont limités par la technologie, la bande passante de communication n’étant pas infinie. De plus, tous les systèmes techniques peuvent rencontrer des défauts et des échecs. Il s’agit là d’un défi majeur pour la conception de dispositifs ATO robustes et efficaces, car la manière habituelle de traiter ces problèmes consiste à utiliser des capteurs de technologies différentes pour chaque information source d’intérêt. Cela rend ce système plus complexe, souvent plus coûteux, et augmente considérablement la quantité de données transmises et son infrastructure de support. Il existe une solution prometteuse à ce défi. Il s’agit de capteurs virtuels, ou observateurs développés par des chercheurs en contrôle automatique pour compléter les capteurs à une fraction du coût, et intégrer la connaissance du système dans l’automate à l’aide de modèles analytiques de l’environnement. La conception d’un type particulier d’observateur et son utilisation pratique pour l’exploitation automatique des trains constituent l’apport principal de cette thèseMillions of people use the trains every day. Therefore, rail transport and infrastructure efficiency and safety is critical, for customers and companies. A major challenge nowadays is to climb automation levels for trains, from Grade of Automation (GoA) “0” which is basically on-sight train operation all the way to GoA “4” where train operations are unattended. GoA levels are defined by the International Association of Public Transport (UITP—French acronym), and aim to provide a roadmap for the development and the integration of the so-called automatic train operation (ATO) systems. ATO are operational safety enhancement devices that help the driver by automating some operations on the train, helping him/her to be more attentive and to focus on possible safety issues or unexpected situations. Currently, the level of automation that is reached for commercial rolling stock is GoA “2”, semi-automatic train operation, when starting and stopping operations are automated. Most of the existing ATO systems are GoA 2. As within any modern vehicle, on-board systems on a train are linked, and the ATO is working together with automatic train protection (ATP) and automatic train supervision (ATS), to ensure the respect of the speed restrictions and stop the train at the station with accuracy and within an acceptable tolerance of its timetable. The stopping task is carried out by automatic train stop control (ATSC), and all of the devices together form a package called automatic train control (ATC) (Dong et al. 2010). All automatic systems rely on two main functions: perception and decision. The ATO device will rely heavily on the available information to ensure an accurate perception of its environment and of the operational situation, in order to carry out the right decisions. This information acquired by sensors of different technologies and made available through the communication network (bus) of the train. Obviously, sensors are limited by technology, the communication bandwidth is not infinite; and all technical systems can experience faults and failures. Those are major challenges to design efficient and robust ATO devices, because the usual way to deal with these issues is to use sensors of different technologies for each information of interest. This makes such a system more complex, possibly costly, and it increases the amount heavily of transmitted data and its supporting infrastructure. There is a promising solution to this challenge, and it is called virtual sensors, or observers that are developed by automatic control researchers to supplement the sensors at a fraction of the cost, and embeds knowledge of the system in the automated device through analytical models of the environment. The design of a particular type of observer, and its practical exploitation for automatic train operations is the main contribution of this PhD work
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Chou, Howard Hao-Yuan. "Fault diagnosis of a heat exchanger system using unknown input observers." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0018/MQ53428.pdf.
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Yang, Dapeng. "Approche algébrique pour l’analyse de systèmes modélisés par bond graph." Thesis, Ecole centrale de Lille, 2012. http://www.theses.fr/2012ECLI0007/document.
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La commande de systèmes physiques s’avère être une tâche difficile en général. En fonction du modèle choisi, les outils mathématiques pour l’analyse et la conception de lois de commande peuvent changés. Pour les systèmes décrits par une représentation entrée-sortie, type transfert, ou par une équation de type état, les principales informations exploitées lors de la phase d’analyse concerne la structure interne du modèle (structure finie) et la structure externe (structure à l’infini) qui permettent avant la phase de synthèse de connaître, sur le modèle en boucle ouverte, les propriétés des lois de commande envisagées ainsi que les propriétés du système piloté (stabilité…).Le travail porte principalement sur l’étude des zéros invariants des systèmes physiques représentés par bond graph, en particulier dans un contexte de modèle type LTV. L’approche algébrique est essentielle dans ce contexte car même si les aspects graphiques restent très proches du cas linéaire classique, l’extension aux modèles LTV reste très complexe d’un point de vue mathématique, en particulier pour le calcul de racines de polynômes. De nouvelles techniques d’analyse des zéros invariants utilisant conjointement l’approche bond graph (exploitation de la causalité) et l’approche algébriques ont permis de mettre en perspective certains modules associés à ces zéros invariants et de clarifier le problème d’annulation des grandeurs de sortie. L’application aux problèmes d’observateurs à entrées inconnues a permis d’illustrer nos propos sur des exemples physiques, avec certaines extensions, problèmes pour lesquels les zéros invariants apparaissent aussi comme éléments essentielsThe control synthesis of physical systems is a complex task because it requires the knowledge of a "good model" and according to the choice of a model some specific tools must be developed. These tools, mainly developed from a mathematical and theoretical point of view, must be used from the analysis step (analysis of model properties) to the control synthesis step. It is well-known that in many approaches, the properties of the controlled systems can be analyzed from the initial model. If the system is described with an input-output representation or with a state space representation, two kinds of information are often pointed out: the external structure (infinite structure) and the internal structure (finite structure). The first one is often related to the existence of some control strategies (input-output decoupling, disturbance decoupling...) and the second one gives some focus on the stability property of the controlled system.In this report, the focus has been on the study of invariant zeros of bond graph models in the context of LTV models. The algebraic approach was essential because, even if the problem is already solved for LTI bond graph models, the extension to LTV models is not so easy. The simultaneous use of algebraic and graphical approaches has been proven to be effective and convenient to solve this problem. First, some tools from the algebraic approach have been recalled in chapter one and results for the study of invariant zeros of LTI bond graph models recalled in chapter two. Some new developments are proposed in chapter three and some applications for the unknown input observer problem with some physical applications conclude this work
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Langueh, Kokou Anani Agbessi. "Estimation en temps fini de systèmes non linéaires et à retards avec application aux systèmes en réseau." Thesis, Ecole centrale de Lille, 2018. http://www.theses.fr/2018ECLI0012/document.
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Cette thèse étudie le problème d'identification de la topologie d'un réseau de systèmes complexes dynamiques, dont les sous-systèmes sont décrits par des équations différentielles ordinaires (EDO) et/ou par des équations différentielles à retard (EDR). La première partie de ce travail porte sur l’identification des paramètres du réseau de systèmes linéaires. Ainsi, différentes classes de systèmes linéaires ont été traitées, à savoir les systèmes sans retard, les systèmes à retard commensurable et les systèmes à entrées inconnues. Un observateur impulsif est proposé afin d'identifier à la fois les états et les paramètres inconnus de la classe de système dynamique considérée en temps fini. Afin de garantir l'existence de l'observateur impulsif proposé, des conditions suffisantes sont déduites. Des exemples illustratifs sont donnés afin de montrer l'efficacité de l'observateur en temps fini proposé.La deuxième partie de ce travail traite le problème de l'identification de la topologie d'un réseau de systèmes dynamiques non linéaires. Dans nos considérations, les coefficients interconnexions de la topologie du réseau sont considérés comme des paramètres constants. Par conséquent, l'identification de la topologie est équivalente à l'identification des paramètres inconnus. Tout d’abord, nous avons déduit des conditions suffisantes sur l’identifiabilité des paramètres, puis nous avons proposé un différenciateur uniforme avec convergence en temps fini pour estimer les paramètres inconnusThis thesis investigates the topology identification problem for network of dynamical complex systems, whose subsystems are described by ordinary differential equations (ODE) and/or delay differential equations (DDE). The first part of this work focuses on the parameters identification of the network of linear systems. Thus, different classes of linear systems have been treated namely systems without delay, systems with commensurable delay and systems with unknown inputs. An impulsive observer is proposed in order to identify both the states and the unknown parameters of the considered class of dynamic system in finite time. In order to guarantee the existence of the proposed impulsive observer, sufficient conditions are deduced. An illustrative example is given in order to show the efficiency of the proposed finite-time observer.The second part of this work treats the topology identification of the network of nonlinear dynamic systems. In our considerations, the topology connections are represented as constant parameters, therefore the topology identification is equivalent to identify the unknown parameters. A sufficient condition on parameter identifiability is firstly deduced, and then a uniform differentiator with finite-time convergence is proposed to estimate the unknown parameters
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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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Blandeau, Mathias. "Modélisation et caractérisation de la stabilité en position assise chez les personnes vivant avec une lésion de la moelle épinière." Thesis, Valenciennes, 2018. http://www.theses.fr/2018VALE0021/document.
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Les personnes vivant avec une lésion de la moelle épinière (LMÉ) subissent une réduction drastique de leurs capacités sensori-motrices en dessous du niveau de la lésion. Cette pathologie influence négativement leur contrôle postural, vu comme le résultat de contributions actives, passives et neuronales. Une approche par modèle est choisie afin de représenter ces différentes contributions et mieux comprendre le contrôle postural en position assise. Deux problèmes apparaissent. Tout d’abord les modèles existants de la position assise sont très rares et inapplicables à l’étude des personnes vivant avec une LMÉ qui, dans l’absence de contrôle musculaire au niveau du tronc, vont utiliser leurs membres supérieurs pour s’équilibrer. De plus, les équations non linéaires sous forme descripteur des modèles biomécaniques existant sont linéarisées dans la majorité des cas afin de simplifier les équations obtenues ce qui n’est plus valable dans le cas de mouvements de grande amplitude. Or des travaux récents fournissent des outils pour analyser ces modèles en utilisant le formalisme de Takagi-Sugeno issu de la logique floue. Ce travail est focalisé sur l’étude du contrôle postural des personnes vivant avec une LMÉ par des outils de l’automatique non linéaire, trois objectifs sont définis : 1. Proposer des modèles biomécaniques non linéaires de la stabilité en position assise pour les personnes vivant avec une LMÉ. 2. Utiliser des méthodes d’écriture de modèle du domaine de l’automatique non linéaire afin de créer les outils nécessaires à l’estimation des variables internes (non mesurées) au modèle. 3. Améliorer la connaissance de la stabilité chez les personnes vivant avec une LMÉ par l’estimation expérimentale d’efforts internes en fonction de paramètres personnels et des conditions expérimentales. Les modèles créés dans ce manuscrit sont, à notre connaissance, les premiers à représenter la stabilité assise en considérant le déplacement des membres supérieurs. Il s’agit également des premiers modèles biomécaniques à utiliser les avancées récentes de l’automatique non linéaire pour l’estimation d’efforts internes non mesurablesThe ability to maintain stability in an unsupported sitting position often becomes challenging after an individuals is affected by a spinal cord injury (SCI). In order to better understand sitting postural control as a combination of active, passive and neuronal contribution, a modelling approach is chosen. Two problems arise; first of all, existing models of sitting control are very scarse and inapplicable to people living with a SCI who will use their upper in a compensatory strategy to balance their trunk. Moreover, the majority of biomechanical models nonlinear equations are linearized with small angle hypothesis for an easier processing which is not acceptable when movements become large. Recent advances in nonlinear control theory provide the theoretical tools for the creation of nonlinear observers using the Takagi-Sugeno fuzzy formalism. This work aims at the study of postural control for people living with a SCI by use of nonlinear tools from control theory; three main goals are formulated: 1. Creating new nonlinear biomechanical models aiming at the study of sitting stability of people living with SCI. 2. Using tools coming from nonlinear control theory to estimate model unmeasured variable 3. Improve the current knowledge on stability for people living with a SCI by estimating internal efforts depending on personal parameters in experimental conditions. The models created in this manuscript are, to the best of our knowledge, the first to consider the upper limbs displacement for the control of sitting stability and the first biomechanical models to use the recent advances in nonlinear control theory for the estimation of unmeasured variables
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Meyer, Luc. "Point-wise and interval state observers for dynamical systems with unknown inputs : application to aerospace navigation." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLE038.
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Cette thèse aborde le problème de l’estimation d’état de systèmes dynamiques à entrées inconnues (EI). La première partie de la thèse est consacrée aux observateurs ponctuels. Pour les systèmes linéaires à temps variant (LTV) ou à paramètres variants (LPV) avec EI et bruits gaussiens, un nouvel observateur à minimum de variance est proposé : il affiche des résultats équivalents aux observateurs existants en matière de performance, mais les surpasse par la simplicité de son implémentation et par l’existence d’un résultat de stabilité qui lui est associé. Pour les systèmes linéaires à commutations avec EI, bruits gaussiens et séquence de commutation inconnue, un premier estimateur à minimum de variance est proposé. Pour les systèmes non linéaires, un nouveau filtre de Kalman étendu à EI est proposé: il généralise les résultats existants au cas de systèmes dont l’équation de mesure possède une partie linéaire et une partie non linéaire. Une application à la navigation aérospatiale est proposée. Pour les systèmes LTV et LPV à EI et pertubations à énergie finie, un observateur H∞ est proposé : il généralise et unifie certains résultats existants. La deuxième partie de la thèse est consacrée aux estimations garanties. Dans lecas où les perturbations affectant le système dynamique sont bornées, plusieurs observateurs par intervalle sont construits. Pour des systèmes LPV avec EI, le travail généralise l’existant en relaxant une condition de rang largement utilisée pour le découplage de l’EI. Pour les systèmes linéaires à commutations sans ou avec EI, un observateur par intervalle est proposé pour traiter le cas où la séquence de commutation est inconnue, problème qui n’a jamais été traité jusqu’ici. Finalement, une nouvelle approche d’encadrement de l’état par un observateur algébrique est proposéeThis thesis deals with the problem of state estimation for dynamical systems affected by Unknown Inputs (UI).The first part focuses on point-wise observers. For Linear Time Varying (LTV) or Linear Parameter Varying (LPV) systems with UI and Gaussian noises, a new minimum variance observer is proposed. It equals the existing ones in terms of performance, but overpasses them by its simplicity of implementing and by the existence of an associated stability result. For linear switching systems with Gaussian noises, UI and unknown switching sequence, a first minimum variance estimator is provided. For non linear systems, a new UI Extended Kalman Filter is provided: it generalizes existing results to the case the measurement equation possesses both linear and nonlinear parts. An application for aerospace navigation is proposed. For LTV or LPV systems with UI and finite energy perturbations, an H∞ observer is given : it generalizes and unifies some existing results. The second part focuses on guaranteed set observers. If the perturbations affecting the dynamical system are bounded,several interval observers are provided. For LPV systems with UI, it generalizes some existing results by relaxing a rank condition widely used for UI decoupling. For linear switching systems without or with UI, it provides an interval observer in the case the switching sequence is unknown, which has not been done before. Finally, a new algebraic observer for interval estimation is proposed
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Gonzalez, Vieyra Joel Abraham. "Estimation et Contrôle des Systèmes Dynamiques à Entrées Inconnues et Energies Renouvelables." Thesis, Ecole centrale de Lille, 2019. http://www.theses.fr/2019ECLI0012/document.
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De nos jours, les processus industriels se doivent d’être efficaces, en particulier au niveau de leur production et/ou consommation énergétique.Ce travail vise à améliorer l’efficacité des processus en analysant l’influence des perturbations sur leur comportement, de la phase de conception à la synthèse des contrôleurs/observateurs, ceci dans une approche intégrée.Le problème du Rejet de Perturbation est introduit ainsi que différents types de contrôles permettant d’atténuer et/ou rejeter ces perturbations. Le système de Barre de Torsion est présenté. Une loi de commande basée sur le concept d’état dérivé est présentée et ensuite validée avec comme application le rejet de perturbation. Il est nécessaire d’estimer les grandeurs physiques utilisées dans les différentes expressions de loi de commande. Un observateur à entrées inconnues basé sur la représentation bond graph est rappelé et ensuite étendu au cas multi-variable. C’est la première contribution théorique de ce travail de recherche.Nous comparons ensuite l’efficacité de différentes techniques de commandes pour le rejet de perturbation par simulation sur le système barre de torsion et analysons ainsi l’efficacité de la technique proposée. Une extension théorique au problème du découplage entrée-sortie nous permet de généraliser le problème du rejet de perturbation dans une même démarche intégrée d’analyse et de synthèse. Enfin, ces techniques sont exploitées et analysées sur le système réel. Nous validons ainsi expérimentalement nos résultats.Un modèle très simplifié de centrale hydroélectrique est développé afin d’appliquer les résultats de nos travaux. Un modèle bond graph simplifié est validé par simulationNowadays, industrial processes must be efficient, particularly at the production level and/or energy consumption.This research work aims at improving the process efficiency by analysing the influences of disturbances on their behaviour, from the conception phase to the synthesis of controller/observer, in an integrated approach.The disturbance rejection problem is first introduced as well as different control laws allowing attenuate/reject these disturbances. A control law based on the concept of derivative state variable is presented and validated while applied as disturbance rejection.In order to reject the disturbance, different physical variables must be estimated, such as state variables, derivative state variables as disturbance variables. An unknown input observer based on the bond graph representation is recalled and extended in the multivariable case. It is the first theoretical contribution of this work.We thus compare the efficiency of different so-called «modern control laws» for the disturbance rejection problems by simulation with the Torsion-Bar system example. We analyse the efficiency of our approach. One extension to the Input-Output decoupling problem allows us to extend the disturbance rejection problem to other control law type in an integrated approach. At least, these techniques are applied on the real Torsion-Bar system and compared. We validate our approach.Since this work aims at analysing and developing efficient control laws for industrial processes, a simplified model of a hydroelectric plant is developed, in order to apply our results. A simplified bond graph model is validated with simulations
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Palomba, Ilaria. "State estimation in multibody systems with rigid or flexible links." Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3427127.
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In the multibody field the design of state observers proves useful for several tasks, ranging from the synthesis of control schemes and fault detection strategies, to the identication of uncertain parameters. State observers are designed to obtain accurate estimates of unmeasurable or unmeasured variables. Their accuracy and performance depend on both the estimation
algorithms and the system models. Indeed, on the one hand the estimation algorithms should be able to cope with multibody system (MBS) nonlinearities. On the other, MB models should be suitable to state estimation, i.e. accurate and computationally efficient.
In order to obtain the best results, it has been necessary to develop dierent approaches for rigid-link and flexible-link MBSs.
In the case of rigid-link MBSs, state observers based on nonlinear kinematic models (i.e. kinematic constraint equations) have been developed. When compared to dynamic models, kinematic models present some relevant advantages. In particular, they are less complex and much less aected
by uncertainty. Additionally, though kinematics-based observers do not require force and torque measurements (often dicult to gather) as inputs, they can be successfully employed for estimating unknown forces: to this purpose a novel two-stage approach is proposed in this dissertation.
As far as modeling flexible-link MBSs is concerned, it is more complicated and makes the implementation of kinematics-based observers impossible, since it is not possible to decouple kinematics from dynamics easily. Furthermore, the so called ne motion of such systems is typically described through a large number of elastic coordinates, which in turns leads to high
model dimensions, and to very inefficient, if not impossible to synthesize, state observers. In order to address this issue, firstly, a new strategy has been developed to keep model dimensions to a minimum. Such a strategy leads to a signicant reduction in the size of the models, which, in turns, provide an appropriate representation of the system dynamics in a frequency range of interest. The availability of reduced-dimension but accurate models for flexible-link MBSs poses the way to the synthesis of more efficient observers provided that a suitable estimation algorithm is chosen.
This thesis also collects results from a large number of numerical and experimental tests carried out to validate the intermediate and nal outcomes of the theoretical investigations.Nello studio e nella progettazione di meccanismi e manipolatori (comunemente detti sistemi multibody MB) la sintesi di stimatori dello stato diviene un requisito indispensabile in molteplici applicazioni avanzate, quali ad esempio la fault detection, l'identicazione dei parametri, la sintesi di controllori, o il controllo attivo delle vibrazioni. Gli stimatori dello stato sono progettati per ottenere delle accurate stime di variabili non misurabili o non misurate. Le prestazioni di uno stimatore dipendono tanto dalla scelta di un opportuno algoritmo di stima, che deve essere capace di fronteggiare le nonlinearità dei sistemi MB, quanto dalla modellazione adottata per i sistemi stessi. In particolare, quest'ultima deve essere adatta al processo di stima, nel senso che deve fornire una descrizione accurata del sistema fisico ma al contempo essere efficiente computazionalmente. Al fine di ottimizzare le prestazioni degli stimatori sono stati sviluppati degli approcci di stima diversicati per i sistemi MB a membri rigidi ed a membri flessibili. In riferimento ai sistemi MB a membri rigidi è stato sviluppato un approccio di stima che rafforza significativamente il ruolo delle equazioni di chiusura cinematiche. Infatti esse, rispetto ai modelli dinamici sino ad ora ampiamente utilizzati, presentano alcuni vantaggi tra cui la minore complessità ed incertezza. Questo nuovo approccio permette non solo di ottenere stime dello stato più accurate ma anche di affrontare con successo il problema della stima delle forze incognite attraverso una formulazione del tutto innovativa, chiamata approccio a due stadi ("two-stage approach"). Per quanto concerne la modellazione dei sistemi MB a membri flessibili, essa presenta criticità alquanto diverse dal precedente ambito di indagine, tra cui la difficoltà di disaccoppiare l'analisi cinematica da quella dinamica, che impedisce l'adozione di un approccio cinematico per la stima delle variabili di stato, e le elevate dimensioni dei modelli che usualmente non permettono la sintesi di stimatori computazionalmente efficienti. Tali criticità hanno imposto preliminarmente lo sviluppo di una nuova strategia per la riduzione dei modelli dinamici non lineari configurazione-varianti dei sistemi MB a membri flessibili. Questa nuova strategia di riduzione permette di ottenere dei modelli dinamici di dimensioni significativamente ridotte, ma ugualmente capaci di descrivere accuratamente la dinamica dei sistemi MB a membri flessibili in un intervallo di frequenze d'interesse. La disponibilità di tali modelli ridotti ha reso possibile la successiva implementazione di più efficienti stimatori dello stato anche nonlineari. Nel presente lavoro di tesi sono inoltre raccolti i numerosi risultati derivanti da test sia numerici che sperimentali condotti per dimostrare la validità degli sviluppi teorici discussi.
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TRUMIC, Maja. "Stiffness Estimation and Adaptive Control for Soft Robots." Doctoral thesis, Università degli Studi di Palermo, 2021. http://hdl.handle.net/10447/479659.
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Menghini, Massimiliano. "UIO based quadrotor FDI using kinematic model." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18064/.
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This thesis addresses the fault diagnosis problem
of sensors of a quadcopter system based on GNSS/IMU. The
model considered is a rigid body with 6DoF. Considering its
linearized kinematic model, the proposed FDI scheme is based
on a generalized bank of observers (GBO) designed with the
UIO theory. The fault scenario is composed by multiple but not concurrent faults. The designed scheme is tested using detectability and isolability analysis, identifying the weaknesses of the FDI scheme and investigating appropriate solutions for the fault diagnosis purposes. Afterwards, the scheme was reconfigured by applying the proposed solutions and analyzing that all the requirements in terms of isolability and detectability were met.
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Sahnoun, Mariem. "Observation des systèmes non linéaires : Application à la détection de défauts." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10322/document.
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Parmi les méthodes de diagnostic de défauts issue de l'automatique, la méthode des filtres résiduels permet de synthétiser des filtres générant des signaux (dits résidus) qui sont utilisés à des ns de détection de défauts. Dans notre approche, les filtres résiduels sont obtenus à partir d'observateurs réduits. L'objectif decette thèse est de synthétiser des observateurs et de mettre en évidence leur application à la détection de défauts pour les systèmes non linéaires. Ce mémoire est réparti en deux parties. Dans la première partie, deux contributions ont été présentées. La première concerne les observateurs à entrées inconnues pour les systèmes affines en l'état modulo une injection de sortie. L'approche proposée est une combinaison des techniques de découplage géométrique et des observateurs non linéaires. Des conditions suffisantes ont été données accompagnées d'un algorithme permettant de concevoir un observateur à entrées inconnues permettant d'estimer une partie de l'état indépendamment de la connaissance de certaines entrées. La deuxième contribution consiste à caractériser la classe des systèmes non linéaires qui se transforment en des systèmes en cascade pour lesquels un observateur peut être conçu. Tout d'abord, des conditions nécessaires et suffisantes théoriques ont été données, ensuite un algorithme permettant de calculer ces transformations (diéomorphismes) a été proposé. Enfin, l'ensemble de tous ces difféomorphismes a été caractérisé en montrant que ce dernier est une orbite d'une action d'un groupe particulier sur l'ensemble de tous les difféomorphismes. La deuxième partie de cette thèse concerne la synthèse d'un filtre polytopique Linéaires à Paramètres Variants (LPV) permettant de détecter, isoler et estimer de multiples défauts capteur. L'avantage de ce filtre est de générer deux types de résidus : l'un étant sensible aux défauts et l'autre insensible. Le résidu insensible est utilisé pour fournir une information qualitative supplémentaire de l'efficacité du filtre. La stabilité de ce dernier est analysée au moyen d'Inégalités Matricielles Linéaires (LMI)Among the faults diagnosis methods, the method of residual filters allows to synthesize filters generating signals ( called residues) that are used for fault detection. In our approach, the residual filters are obtained from reduced observers. The objective of this thesis is to synthesize observers and highlight their application to fault detection for nonlinear systems. This thesis is divided into two parts. In the first part, two papers were presented. The rst one relates to the unknown input observers for state ane systems modulo an output injection. The proposed approach is a combination of geometric decoupling techniques and nonlinear observers. We have given sufficient conditions with an algorithm for designing an unknown input observer to estimate a part of the state without the knowledge of some inputs. The second contribution consists to characterize the class of nonlinear systems which can be transformed into cascade systems for which an observer can be designed. First, necessary and sufficient theoretical conditions were given, then an algorithm to compute these transformations (diffeomorphisms) was proposed. Finally, the set of all dieomorphisms was characterized by showing that it is an orbit of an action of a particular group on the set of all dieomorphisms. The second step of the thesis deals with the synthesis of a polytopic Linear Parameter-Varying (LPV) filter to detect, isolate and estimate multiple sensor faults. The advantage of this lter is to generate two types of residuals : one being sensitive to faults and the other is insensitive. The insensitive residual is used to generate an additional qualitative information of the filter efficiency. The stability of the latter has been performed using Linear Matrix Inequality (LMI)
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Zhang, Mei. "Diagnostic de panne et analyse des causes profondes du système dynamique inversible." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30260/document.
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Beaucoup de services vitaux de la vie quotidienne dépendent de systèmes d'ingénierie hautement complexes et interconnectés; Ces systèmes sont constitués d'un grand nombre de capteurs interconnectés, d'actionneurs et de composants du système. L'étude des systèmes interconnectés joue un rôle important dans l'étude de la fiabilité des systèmes dynamiques; car elle permet d'étudier les propriétés d'un système interconnecté en analysant ses sous-composants moins complexes. Le diagnostic des pannes est essentiel pour assurer des opérations sûres et fiables des systèmes de contrôle interconnectés. Dans toutes les situations, le système global et / ou chaque sous-système peuvent être analysés à différents niveaux pour déterminer la fiabilité du système global. Dans certains cas, il est important de déterminer les informations anormales des variables internes du sous-système local, car ce sont les causes qui contribuent au fonctionnement anormal du processus global. Cette thèse porte sur les défis de l'application de la théorie inverse du système et des techniques FDD basées sur des modèles pour traiter le problème articulaire du diagnostic des fautes et de l'analyse des causes racines (FD et RCA). Nous étudions ensuite le problème de l'inversibilité de la gauche, de l'observabilité et de la diagnosticabilité des fauts du système interconnecté, formant un algorithme FD et RCA multi-niveaux basé sur un modèle. Ce système de diagnostic permet aux composants individuels de surveiller la dynamique interne localement afin d'améliorer l'efficacité du système et de diagnostiquer des ressources de fautes potentielles pour localiser un dysfonctionnement lorsque les performances du système global se dégradent. Par conséquent, un moyen d'une combinaison d'intelligence locale avec une capacité de diagnostic plus avancée pour effectuer des fonctions FDD à différents niveaux du système est fourni. En conséquence, on peut s'attendre à une amélioration de la localisation des fauts et à de meilleurs moyens de maintenance prédictive. La nouvelle structure du système, ainsi que l'algorithme de diagnostic des fautes, met l'accent sur l'importance de la RCA de défaut des dispositifs de terrain, ainsi que sur l'influence de la dynamique interne locale sur la dynamique globale. Les contributions de cette thèse sont les suivantes: Tout d'abord, nous proposons une structure de système non linéaire interconnecté inversible qui garantit le fauts dans le sous-système de périphérique de terrain affecte la sortie mesurée du système global de manière unique et distincte. Une condition nécessaire et suffisante est développée pour assurer l'inversibilité du système interconnecté qui nécessite l'inversibilité de sous-systèmes individuels. Deuxièmement, un observateur interconnecté à deux niveaux est développé; Il se compose de deux estimateurs d'état, vise à fournir des estimations précises des états de chaque sous-système, ainsi que l'interconnexion inconnue. En outre, il fournira également une condition initiale pour le reconstructeur de données et le filtre de fauts local une fois que la procédure FD et RCA est déclenchée par tout fauts. D'une part, la mesure utilisée dans l'estimateur de l'ancien sous-système est supposée non accessible; La solution est de la remplacer par l'estimation fournie par l'estimateur de ce dernier sous-systèmeMany of the vital services of everyday life depend on highly complex and interconnected engineering systems; these systems consist of large number of interconnected sensors, actuators and system components. The study of interconnected systems plays a significant role in the study of reliability theory of dynamic systems, as it allows one to investigate the properties of an interconnected system by analyzing its less complicated subcomponents. Fault diagnosis is crucial in achieving safe and reliable operations of interconnected control systems. In all situations, the global system and/or each subsystem can be analyzed at different levels in investigating the reliability of the overall system; where different levels mean from system level down to the subcomponent level. In some cases, it is important to determine the abnormal information of the internal variables of local subsystem, in order to isolate the causes that contribute to the anomalous operation of the overall process. For example, if a certain fault appears in an actuator, the origin of that malfunction can have different causes: zero deviation, leakage, clogging etc. These origins can be represented as root cause of an actuator fault. This thesis concerns with the challenges of applying system inverse theory and model based FDD techniques to handle the joint problem of fault diagnosis & root cause analysis (FD & RCA) locally and performance monitoring globally. By considering actuator as individual dynamic subsystem connected with process dynamic subsystem in cascade, we propose an interconnected nonlinear system structure. We then investigate the problem of left invertibility, fault observability and fault diagnosability of the interconnected system, forming a novel model based multilevel FD & RCA algorithm. This diagnostic algorithm enables individual component to monitor internal dynamics locally to improve plant efficiency and diagnose potential fault resources to locate malfunction when operation performance of global system degrades. Hence, a means of acombination of local intelligence with a more advanceddiagnostic capability (combining fault monitoring anddiagnosis at both local and global levels) to performFDDfunctions on different levels of the plantis provided. As a result, improved fault localization and better predictive maintenance aids can be expected. The new system structure, together with the fault diagnosis algorithm, is the first to emphasize the importance of fault RCA of field devices, as well as the influences of local internal dynamics on the global dynamics. The developed model based multi-level FD & RCA algorithm is then a first effort to combine the strength of the system level model based fault diagnosis with the component level model based fault diagnosis. The contributions of this thesis include the following: Firstly, we propose a left invertible interconnected nonlinear system structure which guarantees that fault occurred in field device subsystem will affect the measured output of the global system uniquely and distinguishably. A necessary and sufficient condition is developed to ensure invertibility of the interconnected system which requires invertibility of individual subsystems. Second, a two level interconnected observer is developed which consists of two state estimators, aims at providing accurately estimates of states of each subsystem, as well as the unknown interconnection. In addition, it will also provide initial condition for the input reconstructor and local fault filter once FD & RCA procedure is triggered by any fault. Two underlyingissues are worth to be highlighted: for one hand, the measurement used in the estimator of the former subsystem is assumed not accessible; the solution is to replace it by the estimate provided by the estimator of the latter subsystem. In fact, this unknown output is the unknown interconnection of the interconnected system, and also the input of the latter subsystem
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Delrot, Sabrina. "Détection de l'encrassement dans un échangeur de chaleur par observateurs de type Takagi-Sugeno." Phd thesis, Université de Valenciennes et du Hainaut-Cambresis, 2012. http://tel.archives-ouvertes.fr/tel-00739023.
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Le phénomène d'encrassement dans les échangeurs thermiques est actuellement un sujet important. En effet l'encrassement est un phénomène couteux qui provoque (directement ou indirectement via un surdimensionnement des installations) une augmentation des pertes énergétiques, une hausse de la consommation d'eau. Par effet lié, l'encrassement a un impact environnemental non négligeable dû principalement à une augmentation de l'émission de dioxyde de carbone. La détection de l'encrassement peut se faire de manière très ponctuelle en utilisant des capteurs spécifiques et coûteux ou, globalement, soit en mesurant la variation de masse de l'échangeur, soit en évaluant l'efficacité de l'échangeur à travers le coefficient de transfert - ces deux dernières méthodes exigeant des conditions de fonctionnement très particulières : l'arrêt pour la première et un fonctionnement en régime permanent pour la seconde. Les travaux présentés dans cette thèse consistent au développement d'observateurs non linéaires qui permettent de détecter l'encrassement suffisamment tôt pour mettre en place un système d'entretien efficace. Pour cela, un modèle de dimension finie d'un échangeur tubulaire à contre courant a été défini en début de thèse. Trois solutions basées sur le développement d'observateurs non linéaires de type Takagi-Sugeno appliqués au problème de détection d'encrassement dans les échangeurs thermiques sont proposées. La première consiste en une batterie d'observateurs qui estime les paramètres d'encrassement par une méthode d'interpolation. La deuxième propose un observateur polynomial de type Takagi-Sugeno en utilisant la théorie des sommes de carrés. Enfin, un observateur de type Takagi-Sugeno à entrées inconnues est développé. Une comparaison entre ces différentes méthodes est effectuée en conclusion cette thèse.
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Ellero, Nicolas. "Synthèse d’observateurs intervalles à entrées inconnues pour les systèmes linéaires à paramètres variants." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0106/document.
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Cette thèse porte sur la conception d’une classe particulière d’estimateurs d'état, les observateurs intervalles. L’objectif est d’estimer de manière garantie, les bornes supérieure et inférieure de l’ensemble admissible de l'état d’un système, à chaque instant de temps. L’approche considérée repose sur la connaissance a priori du domaine d’appartenance, supposé borné, des incertitudes du système (incertitudes de modélisation, perturbations, bruits, etc). Une classe d'observateurs intervalles à entrées inconnues est proposée pour la classe des systèmes Linéaires à Paramètres Variants (LPV). La synthèse des paramètres de l’observateur repose sur la résolution d’un problème d’optimisation sous contraintes de type inégalités matricielles linéaires (LMI) permettant de garantir simultanément les conditions d’existence de l’observateur ainsi qu’un niveau de performance, soit dans un contexte énergie, soit dans un contexte amplitude ou soit dans un contexte mixte énergie/amplitude. Plus particulièrement, la performance de l'observateur repose sur une technique de découplage pour annuler les effets des entrées inconnues et une technique d’optimisation destinée à minimiser, au sens de critères de type gain L2et/ou gain L∞, les effets des perturbations sur la largeur totale de l’enveloppe de l'état du système LPV. La méthodologie de synthèse proposée est illustrée sur un exemple académique. Enfin, la méthodologie est appliquée au cas de la phase d’atterrissage du véhicule spatial HL20, sous des conditions de simulations réalistesThis thesis addresses the design of a class of estimator, named interval obser-ver, which evaluates in a guaranteed way, a set for the state of the system at each instant of time. The proposed approach is based on a priori knowledge of bounded sets for the system uncertainties (modeling uncertainties, disturbances, noise, etc.). A methodology to design an interval observer is proposed for the class of Linear Parameter Varying (LPV) Systems. The feasibility of the latter is based on the resolution of linear Matrix Inequalities (LMI) constraints allowing to simultaneously get the existence conditions of the intervalobserver and a certain level of a priori given performance for the state estimation of the system. Specifically, the performance of the estimates is based on a decoupling technique to avoid the effects of unknown inputs and an optimization technique to minimize, in the L2 and/or L∞ gain sense, the effects of disturbances on the estimated interval length for the state of the LPV system. The design methodology is illustrated on academic examples.Finally, the methodology is applied on the landing phase of the HL20 shuttle
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Dimassi, Habib. "Synchronisation des systèmes chaotiques par observateurs et applications à la transmission d'informations." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00856590.
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Dans ce travail de thèse, nous développons des méthodes de synchronisation des systèmes chaotiques pour les applications de transmission d'informations. La première méthode de synchronisation que nous proposons est basée sur les observateurs adaptatifs à entrées inconnues pour une classe des systèmes chaotiques présentant des incertitudes paramétriques et des perturbations dans leurs dynamiques et du bruit dans les signaux de sortie (bruit dans le canal de communication). La méthode développée repose sur les techniques adaptatives pour la compensation des non-linéarités et des incertitudes paramétriques et pour la restauration des messages transmis. Elle se base également sur les méthodes de synthèse d'observateurs à entrées inconnues pour supprimer l'influence des perturbations et du bruit. Ensuite, nous développons une deuxième méthode de synchronisation utilisant un observateur adaptatif à ''modes glissants" pour une classe des systèmes chaotiques présentant des entrées inconnues et dont les signaux de sortie sont bruités. La synthèse de l'observateur s'appuie sur la théorie des modes glissants, les techniques de synthèse d'observateurs singuliers et les techniques adaptatives dans le but d'estimer conjointement l'état et les entrées inconnues malgré la présence du bruit dans les équations de sortie. Cette approche de synchronisation est ensuite employée dans un nouveau schéma de communication chaotique sécurisée dont l'objectif est d'augmenter le nombre et l'amplitude des messages transmis, améliorer le niveau de sécurité ainsi que la robustesse aux bruits présents dans le canal de communication. En outre, le scénario de présence des retards de transmission est étudié en élaborant une troisième approche de synchronisation à base d'observateurs adaptatifs pour une classe des systèmes chaotiques de Lur'e avec des non-linéarités à pente restreinte et des signaux de sortie retardés. En se basant sur la théorie de Lyapunov-Krasovskii et en utilisant une hypothèse d'excitation persistante, l'observateur adaptatif proposé garantit la synchronisation maitre-esclave et la restauration des informations transmises malgré l'existence des retards de transmission. Les résultats théoriques obtenus dans ce travail de thèse sont vérifiés à travers des applications de transmission d'informations utilisant différents modèles des systèmes chaotiques tout en étudiant les différents scénarios et cas de figure pouvant se présenter en pratique et en analysant les aspects de sécurité de ces systèmes.
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Ichalal, Dalil. "Estimation et diagnostic de systèmes non linéaires décrits par un modèle de Takagi-Sugeno." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2009. http://tel.archives-ouvertes.fr/tel-00454793.
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Cette thèse traite le problème de l'estimation d'état, du diagnostic et de commande tolérante aux défauts des systèmes non linéaires représentés par un modèle de Takagi-Sugeno (T-S) à variables de prémisse non mesurables. De nombreux algorithmes pour la synthèse d'observateurs robustes vis-à-vis des perturbations, des imperfections de modélisation et des entrées inconnues sont présentés en se basant sur quatre types d'observateurs : les observateurs proportionnels, les observateurs à entrées inconnues, les observateurs proportionnel intégral (PI) et multi-intégral (PMI). Par la suite, ces derniers sont utilisés pour le diagnostic de fautes des systèmes non linéaires. Ceci est réalisé au moyen de trois stratégies. La première utilise l'observateur à entrée inconnue par découplage afin de rendre l'observateur insensible à certains défauts et permettre de détecter et d'isoler les défauts en construisant des bancs d'observateurs. En raison des conditions structurelles souvent insatisfaites, le découplage total des défauts de l'erreur d'estimation d'état n'est pas réalisable. Afin de s'affranchir de ces contraintes, la seconde stratégie utilise les observateurs PI et PMI pour estimer simultanément l'état et les défauts du système. La troisième stratégie qui utilise le formalisme H_inf vise à concevoir un générateur de résidus minimisant l'influence des perturbations et maximisant l'influence des défauts. Un choix adéquat des paramètres du générateur de résidus permet la détection, la localisation et l'estimation des défauts. Enfin, une loi de commande tolérante aux défauts par poursuite de trajectoire d'un modèle de référence est proposée en exploitant les observateurs PI et PMI.
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Pérez, Estrada Abraham Jashiel. "Observateurs adaptatifs des systèmes LPV : application à la commande et au diagnostic." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0069.
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Dans cette thèse, la conception d’observateurs pour les systèmes linéaires à paramètres variables (LPV) et leurs applications au diagnostic et à la commande tolérante aux fautes est étudiée. Un système LPV peut approcher le comportement dynamique non linéaire via un ensemble de modèles linéaire interpolés par un mécanisme dépendant de variables de planification. L’observateur utilisé dans cette recherche s’appelle l’Observateur Dynamique Généralisé (GDO), où l’idée principale est d’ajouter une structure dynamique pour augmenter ses degrés de liberté, dans le but d’obtenir une précision en régime permanent et d’améliorer la robustesse de l’erreur d’estimation contre les perturbations et les incertitudes paramétriques. Par conséquent, cette structure peut être considérée comme plus générale qu’un observateur proportionnel ou qu’un observateur proportionnel intégral. Le sujet traite de la synthèse de GDO pour les systèmes LPV avec des variables d’ordonnancement mesurées et non mesurées, telles que les systèmes quasi-LPV, dans lesquels les variables d’ordonnancement sont des fonctions de signaux endogènes (les états, les entrées ou les sorties), au lieu de signaux exogènes. Les conditions d’existence et de stabilité de chaque structure de GDO sont définies par l’approche de Lyapunov en utilisant une fonction de Lyapunov qui peut être indépendante dépendante des paramètres. La conception est obtenue en termes d’un ensemble d’inégalités matricielles linéaires (LMIs). Les applications d’ingénierie illustrent la performance et l’efficacité des approches proposées. Dans la dernière partie, une stratégie de commande tolérante aux fautes (FTC) pour les systèmes LPV polytopiques, afin de maintenir le système proche des performances souhaitées et de préserver les conditions de stabilité en présence de défauts d’actionneurs. Une unité de diagnostic des défauts est construite pour estimer les états, les défauts d’actionneurs et la variation des paramètres, ces informations sont essentielles à la loi FTCIn this thesis, the observer design for linear parameter-varying systems and their applications to fault diagnosis and fault-tolerant control is studied. A linear parameter-varying (LPV) system can approximate the nonlinear dynamic behavior through a set of linear state space models that are interpolated by a mechanism depending on the scheduling variables. The observer used in this research is called generalized dynamic observer (GDO), where the principal idea is to add dynamics structure to increase its degrees of freedom, with the purpose of achieving steady-state accuracy and improve robustness in estimation error against disturbances and parametric uncertainties. Therefore, this structure can be considered as more general than a proportional observer and proportional-integral observer. It addresses the GDO synthesis for LPV systems with measured and unmeasured scheduling variables such as the quasi-LPV system, in which the scheduling variables are functions of endogenous signals such as states, inputs, or outputs instead of exogenous signals. Conditions of existence and stability for each GDO structure are given through the Lyapunov approach using parameter-independent Lyapunov function or parameter-dependent Lyapunov function. The design is obtained in terms of a set of linear matrix inequalities. Engineering applications are used to illustrates the performance and effectiveness of the proposed approaches. It considers a fault-tolerant control (FTC) strategy for polytopic LPV systems to maintain the current system close to the desired performance and preserve stability conditions in the presence of actuator faults. A fault diagnosis unit is built to estimate the states, the actuator faults, and the parameter variation. That information is essential to the FTC law
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Orjuela, Rodolfo. "Contribution à l'estimation d'état et au diagnostic des systèmes représentés par des multimodèles." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2008. http://tel.archives-ouvertes.fr/tel-00359631.
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Nombreux sont les problèmes classiquement rencontrés dans les sciences de l'ingénieur dont la résolution fait appel à l'estimation d'état d'un système par le biais d'un observateur. La synthèse d'un observateur n'est envisageable qu'à la condition de disposer d'un modèle à la fois exploitable et représentatif du comportement dynamique du système. Or, la modélisation du système et la synthèse de l'observateur deviennent des tâches difficiles à accomplir dès lors que le comportement dynamique du système doit être représenté par un modèle de nature non linéaire. Face à ces difficultés, l'approche multimodèle peut être mise à profit.Les travaux présentés dans cette thèse portent sur les problèmes soulevés par l'identification, l'estimation d'état et le diagnostic de systèmes non linéaires représentés à l'aide d'un multimodèle découplé. Ce dernier, composé de sous-modèles qui peuvent être de dimensions différentes, est doté d'un haut degré de généralité et de flexibilité et s'adapte particulièrement bien à la modélisation des systèmes complexes à structure variable. Cette caractéristique le démarque des approches multimodèles plus conventionnelles qui ont recours à des sous-modèles de même dimension.
Après une brève introduction à l'approche multimodèle, le problème de l'estimation paramétrique du multimodèle découplé est abordé. Puis sont présentés des algorithmes de synthèse d'observateurs d'état robustes vis-à-vis des perturbations, des incertitudes paramétriques et des entrées inconnues affectant le système. Ces algorithmes sont élaborés à partir de trois types d'observateurs dits à gain proportionnel, à gain proportionnel-intégral et à gain multi-intégral. Enfin, les différentes phases d'identification, de synthèse d'observateurs et de génération d'indicateurs de défauts sont illustrées au moyen d'un exemple académique de diagnostic du fonctionnement d'un bioréacteur.
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Soualmi, Boussaad. "Coopération Homme Machine pour la conduite automatisée : une approche par partage haptique du contrôle." Thesis, Valenciennes, 2014. http://www.theses.fr/2014VALE0007/document.
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Le travail présenté dans la thèse s’inscrit dans le projet de recherche partenarial ANR-ABV 2009 dont l’objet est la conception d’un système de conduite automatisée à basse vitesse. Il décrit et analyse les principes d’un contrôle partagé d’un véhicule automobile entre un conducteur humain et un copilote électronique (E-copilote). L’objectif est de mettre en place une coopération Homme-Machine efficace entre le conducteur et l’E-copilote. Un des enjeux est notamment de permettre au conducteur d’interagir avec l’E-copilote de façon continue pour pouvoir exécuter les manœuvres qu’il souhaite sans nécessiter la désactivation ni être gêné par l’E-copilote. Cet enjeu répond au besoin de prise en compte des actions du conducteur entreprises pour pallier celles du E-copilote dans certaines situations par exemple éviter un obstacle non perçu par le système. L’objectif dans ce cas est de garantir le confort au conducteur ainsi que sa conscience du mode engagé (système actif ou pas). Le conducteur et l’E-copilote agissant simultanément sur le système de direction, chacun doit être conscient des actions de l’autre : une communication bidirectionnelle est essentielle. Pour atteindre cet objectif, nous avons retenu les interactions haptiques à travers le système de direction du véhicule. Le couple appliqué par le conducteur sur volant est utilisé par l’E-copilote pour prendre en compte ces actions de la même façon que le couple produit par l’E-copilote est ressenti par le conducteur et utilisé pour comprendre le comportement du système. D’autres aspects essentiels pour la coopération H-M ont également été abordés : l’´étude des changements de modes de fonctionnement du système ainsi que l’IHM via laquelle le conducteur interagit avec le systèmeThe work presented in the thesis is part of the research partnership project ANRABV 2009 which aims is to design an automated low-speed driving. It describes and analyzes the principles of shared control of a motor vehicle between a human driver and an electronic copilot (E-copilot). The objective is to establish effective human-machine cooperation between the driver and E-copilot. One issue is particular to allow the driver to interact with the E-copilot continuously in order to perform maneuvers he wants without requiring deactivation neither constrained by E-copilot. This issue addresses the need for consideration of driver actions taken to remedy those of E-copilot for example avoiding undetected obstacle by the system while ensuring operator comfort and the driver situation awareness. The driver and E-co-pilot acting simultaneously on the steering system, everyone must be aware of the actions of the other: twoway communication is essential. To achieve this goal, we used the haptic interactions through the steering system of the vehicle. The torque applied by the driver on the steering wheel is used by the E-copilot to take into account these actions as the torque produced by the E-copilot is felt by the driver and used to understand the system’s behavior. Other key issues for the Human-Machine Cooperation were also discussed: the study of changes in modes of operation of the system and HMI via which the driver interact with the system
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Houng, Yow-Choung, and 洪祐崇. "Applications of the Optimal Unknown Input Observer for CNC Machine Contouring." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/09770508289806617899.
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碩士國立交通大學
控制工程系
82
In precise manufacturing industries, the accuracy of machin- ing process is the most important requirement. However, In prac- tice, the cutting torque and friction act as the external distu- rbance which decreases the accuracy of machining process badly. Therefore it is crucial to reduce the influence of external disturbance in the precise motion control. In recent two decades, major studies focus on deriving the necessary and sufficient conditions for the existence of unknown input observer (UIO). Few of them have been used for real appli- cations. In this reaaacher, by appling the 2-delay output method to the genernal-structured UIO, a stabilized UIO (S-UIO) is der- ived for non-minimum phase system to estimate both states and unknown inputs. When plant process and measurements are disturb- ed by noises, an algorithm for constructing aaaan optimal S-UIO is derived to minimize the variance of estimation errors. In the present experiments, an external load is added to the X-Y position table with four different controller''s structures (P, CCC, ZPETC, CCC+ZPETC). The Optimal S-UIO estimates disturb- ance for compensating torque so that the effect of external disturbance can be reduced. Experimental results show that both the contouring and tracking errors have been successfully degraded and prove that the proposed method is suitable for motion control.
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PHONG, VU VAN, and 宇文鋒. "Unknown Input Method Based Observer and Controller Synthesis for Uncertain Nonlinear Systems." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/5tf57h.
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博士國立中央大學
電機工程學系
106
Observer and controller design for nonlinear systems is categorized as a great challenge for researchers. In general, because a nonlinear system may have a complex form, observer and controller design may be difficult. Therefore, transforming the nonlinear system into other models is always necessary. In this study, the nonlinear system is transformed into four models which are the discrete time uncertain T-S fuzzy model, uncertain polynomial model, uncertain polynomial T-S fuzzy model and continuous time T-S fuzzy system with the disturbance, then the observer and controller are synthesized for these system models instead of the original nonlinear systems. Particularly, in this dissertation, the observer is synthesized for the discrete time uncertain T-S fuzzy systems, uncertain polynomial T-S fuzzy system; and the observer-based controller is designed for the continuous T-S fuzzy systems with disturbances and the uncertain polynomial systems. It is noted that with the existing of the uncertainties and disturbances, synthesizing the observer and controller for the nonlinear systems becomes much more difficult. Because the uncertainties/disturbances always make the estimation errors and the states be unable to converge zero asymptotically. In this dissertation, the contributions are presented in four main chapters. In Chapter 3, a new methodology based on the unknown input method is proposed for synthesizing the observer to estimate the un-measurable state variables of the discrete time uncertain T-S fuzzy system. This new approach allows us not only eliminate the effects of uncertainties but also make the estimated states approach to real states asymptotically without knowing the upper bounds of the uncertainties. Moreover, both premise variables are dependent and independent on the unmeasured state variables are investigated for the discrete time uncertain T-S fuzzy system. Additionally, the non-common quadratic Lyapunov function is employed to make the conditions for the observer design be more relaxed. In Chapter 4, a new approach to design the observer for uncertain polynomial T-S fuzzy system is proposed. The upper bounds of the uncertainties are not given in advance. A novel polynomial observer form is proposed to estimate the un-measurable states and eliminate completely the influences of the uncertainties without designing a controller and knowing the upper bounds of the uncertainties. Moreover, with the aids of the non-common Lyapunov function and SOS technique, the sufficient conditions for observer synthesis are derived. Furthermore, new methodology to synthesize the observer-based controller for the uncertain polynomial system is established in Chapter 5. The uncertain polynomial system is transformed into the polynomial system with the disturbance then the observer-based controller is designed for this system. The novel control process based on the unknown input method is proposed to estimate states and stabilize the system in which the upper bounds of uncertainties and all/some states are unknown. Besides, a new framework of the observer is synthesized to estimate the un-measurable states and the disturbances simultaneously. In Chapter 6, the observer-based controller is synthesized to the continuous T-S fuzzy system with the presence of the disturbance. The class of the disturbance is significantly enlarged because it does not need to satisfy the strict constraints such as bounded, finite derivative is equal to zero or generated from the exogenous model. A new form of the state and disturbance observer is proposed to estimate the unmeasurable states and disturbance simultaneously. The controller incorporating with the state and disturbance observer is designed to counteract to the impacts of the disturbance and stabilize the system. In conclusion, this dissertation proposed several methods to synthesize observer and controller for the uncertain nonlinear system. On the basis of Lyapuov theory, the conditions of design observer and controller are derived in term of LMIs (Linear Matrix Inequalities) and SOS (Sum of Squares) which can be solved by LMIs tool and SOS tools in Matlab. Finally, several examples are shown to illustrate the effectiveness and advantages of the proposed methods.
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Chu, Tzu-Chung, and 朱子忠. "A VSS using unknown input observer and backstepping technique with application to motor control." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/41040748498743785279.
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碩士中華大學
電機工程學系碩士班
89
In this thesis, we consider the variable structure system (VSS) control using the backstepping technique to deal with the mismatched uncertainty and apply our theoretical results to DC motor velocity control. In the presence of mismatched friction force, the unknown input observer is then used to provide the estimates of the states of the system as well as the friction term. With these estimates, the VSS control method is used to fulfill the backstepping control method for DC motor velocity control. The overall system performance is determined by a first-order transfer function with unit DC gain and arbitrary bandwidth.
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Shen, Li-Cheng, and 沈里正. "An Eigenstructure Assignment Approach to the Design of Unknown Input Fault Isolation Observer (UIFIO)." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/22950787411084909628.
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碩士國立交通大學
控制工程系
82
As the demands on safety and reliablity of automatically co- ntrolled system become more stringent,a good control system has to not only achieve the performacne requirements but also guara- tee the safety concern. In this thesis, an UIFIO (unknown input fault isolation obs- erver) will be firstly proposed with eigenstructure assignment and the corresponding numerical algorithm will also be summari- zed. With the flexiblity provided by output feedback in multiva- riable systems beyond closed-loop eigenvalure assignment, the f- ault diagnostic observer decouples the structured uncertanity f- rom residual outputs and performs isolation for any possible co- mbination of failure occurrences. Furthermore, since the robust- ness of the diagnostic observer relative to unstructured uncert- ainty depends on the condition number of closed-loop eigenvecto- r set, two constrained approximations for minimizing condition number of closed-loop eigenvector assignment based on the UIFIO are proposed. With these two approximation methods, a locally optimal solution of closed- loop eigenvector set can be found to suppress the effects induced by unstructured uncertanity.
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Wei-XiangJian and 簡偉翔. "A New Input Constrained Tracker for an Unknown Sampled-Data System: Modified Observer-Based Model Predictive Control Approach." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/3m6fby.
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碩士國立成功大學
電機工程學系
103
This thesis proposes a modified observer-based model predictive control tracker for linear unknown system with a direct transmission term and input constraint. First, the observer/Kalman filter identification(OKID) is used to identify the unknown and linear system with a transmission term into the equivalent mathematical model containing a transmission term. This identified model is used for the design of the controller and observer. Besides, the prediction-based digital redesign method is utilized to obtain a relatively low-gain and implementable observer and digital tracker from the theoretically well-designed high-gain analogue observer and tracker. The proposed modified observer-based model predictive control not only reduces the control input to fit the requirement of the input constraint, but also possesses the high-gain property of controlled system.
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Wen-TengHsu and 許文騰. "An Input-Constrained Reduced-Order Observer and NARMAX Model-Based Adaptive Tracker with Fault Tolerance for Unknown Systems with an Input-Output Direct Feed-Through Term." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/11400392290801017705.
Full textAbstract:
博士國立成功大學
電機工程學系
102
This dissertation proposes an input-constrained reduced-order observer-based adaptive tracker with fault tolerance for unknown nonlinear stochastic systems with an input-output direct feed-through term to obtain good tracking performance. The major contributions of this dissertation are stated as follows: Firstly, realization of causal current output-based optimal full/reduced-order observer and tracker for the linear sampled-data system with a direct transmission term from input to output is newly proposed. Furthermore, the time derivative of the control input existed in the continuous-time reduced-order observer can be avoided in the proposed one for the continuous-time system with an input-output feed-through term. Secondly, an active full-order fault tolerance tracker using the modified nonlinear autoregressive moving average with exogenous inputs (NARMAX) model for state-space self-tuning control (STC) of unknown nonlinear stochastic hybrid systems with a direct transmission term is proposed. For the system identification process, the initial parameters of the modified NARMAX model assigned by the off-line OKID and can speed up the convergence speed of the recursive extended least squares (RELS) method to determine a reliable dynamic model. Moreover, the modified state-space self-tuning control methodology due to the NARMAX model can quickly make an appropriate reaction to the variation of system parameters when the abrupt input fault and/or the gradual input fault occurs. Finally, an input-constrained reduced-order observer-based self-tuner with fault tolerance for unknown nonlinear stochastic systems with an input-output direct feed-through term has been proposed. Some illustrative examples are given to demonstrate the effectiveness of the proposed methodologies.
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(5930930), Nathaniel T. Woodford. "Robust Sensor Selection Strong Detectability." Thesis, 2019.
Find full textAbstract:
An unknown input observer provides perfect asymptotic tracking of the state of a system affected by unknown inputs. Such an observer exists (possibly requiring a delay in estimation) if and only if the system satisfies a property known as strong detectability. In this thesis, we consider the problem of selecting (at design-time) a minimum cost subset of sensors from a given set to make a given system strongly detectable. We show this problem is NP-hard even when the system is stable. Furthermore, we show it is not possible to approximate the minimum cost within a factor of log(n) in polynomial-time (unless P=NP). However, we prove if a given system (with a selected set of sensors) is already strongly detectable, finding the smallest set of additional sensors to install to obtain a zero-delay observer can be done in polynomial time. Next we consider the problem of attacking a set of deployed sensors to remove the property of strong detectability. We show finding the smallest number of sensors to remove is NP-hard. Lastly through simulations, we analyze two greedy approaches for approximating the strong detectability sensor selection problem.
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Chih-HaoLee and 李至浩. "A New Linear Quadratic Observer and Tracker under Input Constraint for the Unknown System with a Direct Feedthrough Term: Digital Redesign Approach." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/n57z7d.
Full textAbstract:
碩士國立成功大學
電機工程學系碩博士班
101
This thesis develops a new linear quadratic observer and tracker for the linear unknown system with a direct transmission term from input to output. The off-line observer/Kalman filter identification (OKID) method is used to determine the sampled-data linear model with a direct feedthrough term. Based on this model, a high-gain optimal linear quadratic analogue observer-based tracker are proposed, so that it can effectively induce a high quality performance on the state estimation and the trajectory tracking design. Besides, the prediction-based digital redesign method is utilized to obtain a relatively low-gain and implementable observer and digital tracker from the theoretically well-designed high-gain analogue observer and tracker for the linear system with a direct transmission term from input to output. To reduce the magnitude of control input, which is caused by the high-gain property to fit the requirement of the input constraint, the modified linear quadratic analogue tracker (LQAT) is proposed. Thus, the control input can be compressed effectively without losing the original high performance of tracking much.
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Bolandhemmat, Hamidreza. "Distributed Sensing and Observer Design for Vehicles State Estimation." Thesis, 2009. http://hdl.handle.net/10012/4471.
Full textAbstract:
A solution to the vehicle state estimation problem is given using the Kalman filtering and the Particle filtering theories. Vehicle states are necessary for an active or a semi-active suspension control system, which is intended to enhance ride comfort, road handling and stability of the vehicle. Due to a lack of information on road disturbances, conventional estimation techniques fail to provide accurate estimates of all the required states. The proposed estimation algorithm,
named Supervisory Kalman Filter (SKF), consists of a Kalman filter with an extra update step which is inspired by the particle filtering technique. The extra step, called a supervisory layer, operates on the portion of the state vector that cannot be estimated by the Kalman filter. First, it produces N randomly generated state vectors, the particles, which are distributed based on the Kalman filter’s last updated estimate. Then, a resampling stage is implemented to collect the
particles with higher probability. The effectiveness of the SKF is demonstrated by comparing its estimation results with that of the Kalman filter and the particle filter when a test vehicle is passing over a bump. The estimation results confirm that the SKF precisely estimates those states of the vehicle that cannot be estimated by either the Kalman filter or the particle filter,
without any direct measurement of the road disturbance inputs.
Once the vehicle states are provided, a suspension control law, the Skyhook strategy,
processes the current states and adjusts the damping forces accordingly to provide a better and safer ride for the vehicle passengers. This thesis presents a novel systematic and practical methodology for the design and implementation of the Skyhook control strategy for vehicle’s
semi-active suspension systems. Typically, the semi-active control strategies (including the Skyhook strategy) have switching natures. This makes the design process difficult and highly dependent on extensive trial and error. The proposed methodology maps the discontinuous
control system model to a continuous linear region, where all the time/frequency design
techniques, established in the conventional control system theory, can be applied. If the semiactive control law is designed to satisfy ride and stability requirements, an inverse mapping offers the ultimate control law. The effectiveness of the proposed methodology in the design of a semi-active suspension control system for a Cadillac SRX 2005 is demonstrated by real-time
road tests. The road tests results verify that the use of the newly developed systematic design methodology reduces the required time and effort in real industrial problems.
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Yi-HsuanChen and 陳毅玹. "Decentralized Modeling and Linear Observers/Input Constraint Trackers for a More General Class of Unknown Large-scale Interconnected Sampled-data Linear Systems with State Delay and Closed-loop Decoupling Property." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/06494754449861473514.
Full textAbstract:
碩士國立成功大學
電機工程學系碩博士班
98
Decentralized modeling and linear observers/input constraint trackers for a more general class of unknown large-scale interconnected sampled-data linear systems with state delay and closed-loop decoupling property are proposed in this thesis. First, the off-line observer/Kalman filter identification (OKID) method is used to determine the appropriate (low-) order decentralized linear observers for the unknown large-scale interconnected sampled-data linear system with state delay. Then, a digital redesign approach with the high-gain property is applied to overcome the modeling error of the above observer effectively. Moreover, a digital-redesign observer-based linear quadratic digital tracker with high-gain property for the sampled-data system is presented, and it provides high performance on trajectory tracking with the closed-loop decoupling property. Finally, to reduce the magnitude of control input, which is caused by the high gain property to fit the requirement of the input constraint, the modified linear quadratic digital tracker (LQDT) is proposed. And the control input can be compressed effectively without losing the original high performance of tracking much.