Дисертації з теми "Fault detection/estimation"
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Zhou, Yilun. "Fault detection and distributed estimation with sensor networks." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/61021.
Повний текст джерелаStocks, Mikael. "Stator fault detection and parameter estimation in induction machines." Licentiate thesis, Luleå, 2002. http://epubl.luth.se/1402-1757/2002/23.
Повний текст джерелаXiong, Jun. "Set-membership state estimation and application on fault detection." Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2013. http://tel.archives-ouvertes.fr/tel-01068054.
Повний текст джерелаShafiei, Mehdi. "Distribution network state estimation, time dependency and fault detection." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/124659/2/Mehdi_Shafiei_Thesis.pdf.
Повний текст джерелаYang, Zaiyue, and 楊再躍. "Fault detection, estimation and control of periodically excited nonlinear systems." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40887984.
Повний текст джерелаYang, Zaiyue. "Fault detection, estimation and control of periodically excited nonlinear systems." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40887984.
Повний текст джерелаSu, Jinya. "Fault estimation algorithms : design and verification." Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/23231.
Повний текст джерелаSalehpour, Soheil. "Fault detection and model quality estimation using mixed integer linear programming /." Luleå : Luleå University of Technology, 2009. http://pure.ltu.se/ws/fbspretrieve/2740260.
Повний текст джерелаZhang, Xiaoxia. "Incipient anomaly detection and estimation for complex system health monitoring." Electronic Thesis or Diss., université Paris-Saclay, 2020. http://www.theses.fr/2020UPASG025.
Повний текст джерелаIncipient fault detection and diagnosis in engineering and multivariate industrial systems with a high-level noise are addressed in this Ph.D. thesis by a ’global’ non-parametric statistical approach. An incipient fault is supposed to induce an abnormal change in the measured value of the system variable. However, such change is weak, and it tends not to cause obvious changes in the signal distribution’s parameters. Especially in high noise level environment, the weak fault feature can be masked by the noise and becomes unpredictable. In such a condition, using traditional parametric-based methods generally fails in the fault detection. To cope with incipient fault detection and diagnosis, a ’global’ approach that can consider the total faults signature is needed. The incipient fault detection can be obtained by measuring the differences between the signal distributions before and after the fault occurrence. Some distribution-based ’global’ methods have been proposed, however, the detection capabilities of these existed approaches in high noise level environment should be improved. In this context, Jensen-Shannon divergence is considered a ’global’ fault indicator to deal with the incipient fault detection and diagnosis in a high noise level environment. Its detection performance for small abnormal variations hidden in noise is validated through simulation. In addition, the fault estimation problem is also considered in this work. A theoretical fault severity estimation model depending on the divergence value for the Gaussian condition is derived. The accuracy of the estimation model is evaluated on numerical models through simulations. Then, the ’global’ statistical approach is applied to two applications in engineering. The first one relates to non- destruction incipient cracks detection. The Jensen-Shannon divergence combined with Noisy Independent Component Analysis and Wavelet analysis was applied for detection and characterization of minor cracks in conductive structures with high-level perturbations based on experimental impedance signals. The second application addresses the incipient fault diagnosis in a multivariate non-linear process with a high-level noise. Tennessee Eastman Process (TEP) is one typical multivariate non-linear process, the Jensen-Shannon divergence in the Kernel Principal Component Analysis (KPCA) is developed for coping with incipient fault detection in this process
Törnqvist, David. "Statistical Fault Detection with Applications to IMU Disturbances." Licentiate thesis, Linköping University, Linköping University, Automatic Control, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-7094.
Повний текст джерелаThis thesis deals with the problem of detecting faults in an environment where the measurements are affected by additive noise. To do this, a residual sensitive to faults is derived and statistical methods are used to distinguish faults from noise. Standard methods for fault detection compare a batch of data with a model of the system using the generalized likelihood ratio. Careful treatment of the initial state of the model is quite important, in particular for short batch sizes. One method to handle this is the parity-space method which solves the problem by removing the influence of the initial state using a projection.
In this thesis, the case where prior knowledge about the initial state is available is treated. This can be obtained for example from a Kalman filter. Combining the prior estimate with a minimum variance estimate from the data batch results in a smoothed estimate. The influence of the estimated initial state is then removed. It is also shown that removing the influence of the initial state by an estimate from the data batch will result in the parity-space method. To model slowly changing faults, an efficient parameterization using Chebyshev polynomials is given.
The methods described above have been applied to an Inertial Measurement Unit, IMU. The IMU usually consists of accelerometers and gyroscopes, but has in this work been extended with a magnetometer. Traditionally, the IMU has been used to estimate position and orientation of airplanes, missiles etc. Recently, the size and cost has decreased making it possible to use IMU:s for applications such as augmented reality and body motion analysis. Since a magnetometer is very sensitive to disturbances from metal, such disturbances have to be detected. Detection of the disturbances makes compensation possible. Another topic covered is the fundamental question of observability for fault inputs. Given a fixed or linearly growing fault, conditions for observability are given.
The measurements from the IMU show that the noise distribution of the sensors can be well approximated with white Gaussian noise. This gives good correspondence between practical and theoretical results when the sensor is kept at rest. The disturbances for the IMU can be approximated using smooth functions with respect to time. Low rank parameterizations can therefore be used to describe the disturbances. The results show that the use of smoothing to obtain the initial state estimate and parameterization of the disturbances improves the detection performance drastically.
Bradley, William J. "Current Based Fault Detection and Diagnosis of Induction Motors. Adaptive Mixed-Residual Approach for Fault Detection and Diagnosis of Rotor, Stator, Bearing and Air-Gap Faults in Induction Motors Using a Fuzzy Logic Classifier with Voltage and Current Measurement only." Thesis, University of Bradford, 2013. http://hdl.handle.net/10454/7265.
Повний текст джерелаThe full-text was made available at the end of the embargo period on 29th Sept 2017.
Qian, Lu [Verfasser]. "Observer-Based Fault Detection and Estimation of Rolling Element Bearing Systems / Lu Qian." Düren : Shaker, 2019. http://d-nb.info/1190525682/34.
Повний текст джерелаBradley, William John. "Current based fault detection and diagnosis of induction motors : adaptive mixed-residual approach for fault detection and diagnosis of rotor, stator, bearing and air-gap faults in induction motors using a fuzzy logic classifier with voltage and current measurement only." Thesis, University of Bradford, 2013. http://hdl.handle.net/10454/7265.
Повний текст джерелаRu, Jifeng. "Adaptive estimation and detection techniques with applications." ScholarWorks@UNO, 2005. http://louisdl.louislibraries.org/u?/NOD,285.
Повний текст джерелаTitle from electronic submission form. "A dissertation ... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Engineering and Applied Science"--Dissertation t.p. Vita. Includes bibliographical references.
Peng, Wei. "Fast Modelling, Torque-Ripple-Reduction and Fault-Detection Control of Switched Reluctance Motors." Doctoral thesis, Universite Libre de Bruxelles, 2019. https://dipot.ulb.ac.be/dspace/bitstream/2013/285757/5/contratWP.pdf.
Повний текст джерелаDoctorat en Sciences de l'ingénieur et technologie
info:eu-repo/semantics/nonPublished
Fani, Mehran. "Fault diagnosis of an automotive suspension system." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
Знайти повний текст джерелаCarbone, Marc A. Carbone. "Development of a Supervisory Tool for Fault Detection and Diagnosis of DC Electric Power Systems with the Application of Deep Space Vehicles." Case Western Reserve University School of Graduate Studies / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1601984256665471.
Повний текст джерелаBoem, Francesca. "Distributed Methods for Estimation and Fault Diagnosis: the case of Large-scale Networked Systems." Doctoral thesis, Università degli studi di Trieste, 2013. http://hdl.handle.net/10077/8534.
Повний текст джерелаL’obiettivo di questa tesi è il monitoraggio di sistemi complessi a larga-scala. L’importanza di questo argomento è dovuto alla rinnovata enfasi data alle problematiche riguardanti la sicurezza e l’affidabilità dei sistemi, diventate requisiti fondamentali nella progettazione. Infatti, la crescente complessità dei moderni sistemi, dove le relazioni fra i diversi componenti, con il mondo esterno e con il fattore umano sono sempre più importanti, implica una crescente attenzione ai rischi e ai costi dovuti ai guasti e lo sviluppo di approcci nuovi per il controllo e il monitoraggio. Mentre nel contesto centralizzato i problemi di stima e di diagnostica di guasto sono stati ampiamente studiati, lo sviluppo di metodologie specifiche per sistemi distribuiti, larga scala o “networked”, come i Cyber-Physical Systems e i Systems-of-Systems, è cominciato negli ultimi anni. Il sistema fisico è rappresentato come l’interconnessione di sottosistemi ottenuti attraverso una decomposizione del sistema complesso dove le sovrapposizioni sono consentite. L’approccio si basa sul modello dinamico non-lineare dei sottosistemi e sull’approssimazione adattativa delle non note interconnessioni fra i sottosistemi. La novità è la proposta di un’architettura unica che tenga conto dei molteplici aspetti che costituiscono i sistemi moderni, integrando il sistema fisico, il livello sensoriale e il sistema di diagnostica e considerando le relazioni fra questi ambienti e le reti di comunicazione. In particolare, vengono proposte delle soluzioni ai problemi che emergono dall’utilizzo di reti di comunicazione e dal considerare sistemi distribuiti e networked. Il processo di misura è effettuato da un insieme di reti di sensori, disaccoppiando il livello fisico da quello diagnostico e aumentando in questo modo la scalabilità e l’affidabilità del sistema diagnostico complessivo. Un nuovo metodo di stima distribuita per reti di sensori è utilizzato per filtrare le misure minimizzando sia la media sia la varianza dell’errore di stima attraverso la soluzione di un problema di ottimizzazione di Pareto. Un metodo per la re-sincronizzazione delle misure è proposto per gestire sistemi multi-rate e misure asincrone e per compensare l’effetto dei ritardi nella rete di comunicazione fra sensori e diagnostici. Poiché uno dei problemi più importanti quando si considerano sistemi distribuiti e reti di comunicazione è per l’appunto il verificarsi di ritardi di trasmissione e perdite di pacchetti, si propone una strategia di compensazione dei ritardi , basata sull’uso di Time Stamps e buffer e sull’introduzione di una matrice di consenso tempo-variante, che permette di gestire il problema dei ritardi nella rete di comunicazione fra diagnostici. Gli schemi distribuiti per la detection e l’isolation dei guasti sono sviluppati, garantendo la convergenza degli stimatori e derivando le condizioni sufficienti per la detectability e l’isolability. La matrice tempo-variante proposta permette di migliorare queste proprietà definendo delle soglie meno conservative. Alcuni risultati sperimentali provano l’efficacia del metodo proposto. Infine, le architetture distribuite per la detection e l’isolation, sviluppate nel caso tempo-discreto, sono estese al caso tempo continuo e nello scenario in cui lo stato non è completamente misurabile, sia a tempo continuo che a tempo discreto.
This thesis deals with the problem of the monitoring of modern complex systems. The motivation is the renewed emphasis given to monitoring and fault-tolerant systems. In fact, nowadays reliability is a key requirement in the design of technical systems. While fault diagnosis architectures and estimation methods have been extensively studied for centralized systems, the interest towards distributed, networked, large-scale and complex systems, such as Cyber-Physical Systems and Systems-of-Systems, has grown in the recent years. The increased complexity in modern systems implies the need for novel tools, able to consider all the different aspects and levels constituting these systems. The system being monitored is modeled as the interconnection of several subsystems and a divide et impera approach allowing overlapping decomposition is used. The local diagnostic decision is made on the basis of the knowledge of the local subsystem dynamic model and of an adaptive approximation of the uncertain interconnection with neighboring subsystems. The goal is to integrate all the aspects of the monitoring process in a comprehensive architecture, taking into account the physical environment, the sensor layer, the diagnosers level and the communication networks. In particular, specifically designed methods are developed in order to take into account the issues emerging when dealing with communication networks and distributed systems. The introduction of the sensor layer, composed by a set of sensor networks, allows the decoupling of the physical and the sensing/computation topologies, bringing some advantages, such as scalability and reliability of the diagnosis architecture. We design the measurements acquisition task by proposing a distributed estimation method for sensor networks, able to filter measurements so that both the variance and the mean of the estimation error are minimized by means of a Pareto optimization problem. Moreover, we consider multi-rate systems and non synchronized measurements, having in mind realistic applications. A re-synchronization method is proposed in order to manage the case of multi-rate systems and to compensate delays in the communication network between sensors and diagnosers. Since one of the problems when dealing with distributed, large-scale or networked systems and therefore with a communication network, is inevitably the presence of stochastic delays and packet dropouts, we propose therefore a distributed delay compensation strategy in the communication network between diagnosers, based on the use of Time Stamps and buffers and the definition of a time-varying consensus matrix. The goal of the novel time-varying matrix is twofold: it allows to manage communication delays, packet dropouts and interrupted links and to optimize detectability and isolability skills by defining less conservative thresholds. The distributed fault detection and isolation schemes are studied and analytical results regarding fault detectability, isolability and estimator convergence are derived. Simulation results show the effectiveness of the proposed architecture. For the sake of completeness, the monitoring architecture is studied and adapted to different frameworks: the fault detection and isolation methodology is extended for continuous-time systems and the case where the state is only partially measurable is considered for discrete-time and continuous-time systems.
XXV Ciclo
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Boche, Adèle. "Méthodes indirectes d'adaptation et de décision pour la sécurisation du vol des drones à voilure fixe." Thesis, Toulouse, ISAE, 2018. http://www.theses.fr/2018ESAE0043/document.
Повний текст джерелаMajor security risks appear with the increase of the number of UAV in the air space. Thus, UAV security is more and more important and Fault Tolerant Control (FTC) methods could support the achievement of acceptable security level. The aims of this research is to develop a FTC method which combines two approaches : Automatic Control approach which is based on model which have a continuous representation of the system and Artificial Intelligence approach which is based on discrete or logical model to represent the system. Thus, the first contribution of this thesis is the development of a generic fault tolerant control method which uses discrete and continuous frameworks. The idea was to combine a continuous framework to estimate the state and fault parameters and a discrete framework to take on line a decision about the controller. The continuous estimation provides more knowledge on the fault whereas a discrete model allows the use of different optimization tools which are more adapted to decision task. The second contribution is the development and the validation of a method for fault detection and diagnosis. For its potential, a Kalman filter is adapted in order to be sensitive to abrupt faults and used for state and fault parameters estimation. These estimates are then used in a probabilistic way to detect and identify the fault. Once the fault is detected, the control system should react to compensate the fault. Thus, the third contribution of this thesis is the improvement of the trajectory tracking by reconfiguration of the control system. The aim is to combine switching and adaptive methods in order to limit the number of controllers by using adaptive controllers for degraded modes while having convenient controllers. Optimization tools are then used to take the decision on the controller to use. Finally, the method has to be validated before being implemented on line. The last contribution is the evaluation of the ability of the method to follow its trajectory despite the apparition of actuator or sensor faults during a landing approach
Farhat, Ahmad. "Détection, localisation et estimation de défauts : application véhicule." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAT056/document.
Повний текст джерелаModern vehicles are increasingly equipped with new mechanisms to improve safety, comfort and ecological impact. These active systems employ sensors, actuators and automatic control systems. However, in case of failure of one these components, the consequences for the vehicle and the passengers safety could be dramatic. In order to ensure a higher level of reliability within on board diagnosis, new methodologies for sensor or actuator fault detection, location and estimation are proposed. These model based approaches are extended for robust synthesis for switched uncertain systems. In addition, a method for detecting critical stability situation is presented. The validation of the different methods is illustrated with simulations using CarSim, and application on real vehicle data within the INOVE project
López, Estrada Francisco Ronay. "Model-based fault diagnosis observer design for descriptor LPV system with unmeasurable gain scheduling." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0162/document.
Повний текст джерелаThis work is dedicated to the synthesis of model-Based fault detection and isolation (FDI) techniques based on observers for nonlinear systems modeled as Descriptor-Linear Parameter Varying (D-LPV) systems. D-LPV systems are a particular class of systems that can represent (or approximate in some degree of accuracy), complex nonlinear systems by a set of linear local models blended through convex parameter-Dependent scheduling functions. The global D-LPV System can describe both time-Varying and nonlinear behavior. Nevertheless, in many applications the time-Varying parameters in the scheduling functions could be unmeasurable. Models which depend on unmeasurable scheduling functions cover a wide class of nonlinear systems compared to models with measurable scheduling functions, but the design of control schemes for D-LPV systems with unmeasurable scheduling functions are more difficult than those with a measurable one, because the design of such control schemes involve the estimation of the scheduling vector. This topic is addressed in this work by considering the following main targets: • to design FDI in D-LPV systems based on -H∞ observers in order to guarantee robustness against disturbances and errors due the unmeasurable gain scheduling functions • to extend the proposed -H∞ methods to perform state estimation and fault detection, isolation and fault magnitude estimation in the case of sensor faults • to guarantee the best trade-Off between fault sensitivity and disturbance rejection by developing H_/H∞ fault detection observers for D-LPV systems. The thesis is organized as follows Chapter 1 is dedicated to provide a general introduction, the objectives and contribution of this work.Chapter 2 is organized in order to provide the minimum necessary elements to describe the representation, modeling, properties, analysis, and observer design of D-LPV systems. Chapter 2 is also dedicated to a detailed review of the state of the art. Chapter 3 is dedicated to the development of three different methods to design fault detection observers for D-LPV systems based on H∞ theory. Finally, the proposed methods are applied to an example, for sensor fault detection and isolation by means of an observer bank, in order to compare the performance of each method. Chapter 4 is dedicated to the design of a FDI method based on observers with H_/H∞ performance. Based on the H_/H∞ approach, which considers the best trade-Off between fault sensitivity and robustness to disturbance, adequate LMIs are obtained to guarantee sufficient conditions for the design problem. In order to illustrate the effectiveness of the proposed techniques, an example is considered
Farfan-Ramos, Luis. "Real-time Fault Diagnosis of Automotive Electrical Power Generation and Storage System." Wright State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=wright1303129393.
Повний текст джерелаHarrysson, Mattias. "Fault Location Algorithms in Transmission Grids." Thesis, Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-26314.
Повний текст джерелаCosta, Bruno Sielly Jales. "Detec??o e diagn?stico de falhas n?o-supervisionados baseados em estimativa de densidade recursiva e classificador fuzzy auto-evolutivo." Universidade Federal do Rio Grande do Norte, 2014. http://repositorio.ufrn.br:8080/jspui/handle/123456789/18577.
Повний текст джерелаCoordena??o de Aperfei?oamento de Pessoal de N?vel Superior
In this work, we propose a two-stage algorithm for real-time fault detection and identification of industrial plants. Our proposal is based on the analysis of selected features using recursive density estimation and a new evolving classifier algorithm. More specifically, the proposed approach for the detection stage is based on the concept of density in the data space, which is not the same as probability density function, but is a very useful measure for abnormality/outliers detection. This density can be expressed by a Cauchy function and can be calculated recursively, which makes it memory and computational power efficient and, therefore, suitable for on-line applications. The identification/diagnosis stage is based on a self-developing (evolving) fuzzy rule-based classifier system proposed in this work, called AutoClass. An important property of AutoClass is that it can start learning from scratch". Not only do the fuzzy rules not need to be prespecified, but neither do the number of classes for AutoClass (the number may grow, with new class labels being added by the on-line learning process), in a fully unsupervised manner. In the event that an initial rule base exists, AutoClass can evolve/develop it further based on the newly arrived faulty state data. In order to validate our proposal, we present experimental results from a level control didactic process, where control and error signals are used as features for the fault detection and identification systems, but the approach is generic and the number of features can be significant due to the computationally lean methodology, since covariance or more complex calculations, as well as storage of old data, are not required. The obtained results are significantly better than the traditional approaches used for comparison
Este trabalho prop?e um algoritmo de dois estagios para detec??o e identifica??o de falhas, em tempo real, em plantas industriais. A proposta baseia-se na analise de caracter?sticas selecionadas utilizando estimativa de densidade recursiva e um novo algoritmo evolutivo de classifica??o. Mais especificamente, a abordagem proposta para detec??o e baseada no conceito de densidade no espa?o de dados, o que difere da tradicional fun??o densidade de probabilidade, porem, sendo uma medida bastante util na detec??o de anormalidades/outliers. Tal densidade pode ser expressa por uma fun??o de Cauchy e calculada recursivamente, o que torna o algoritmo computacionalmente eficiente, em termos de processamento e memoria, e, dessa maneira, apropriado para aplica??es on-line. O estagio de identifica??o/diagnostico e realizado por um classificador baseado em regras fuzzy capaz de se auto-desenvolver (evolutivo), chamado de AutoClass, e introduzido neste trabalho. Uma propriedade importante do AutoClass e que ele e capaz de aprender a partir do zero". Tanto as regras fuzzy, quanto o numero de classes para o algoritmo n?o necessitam de pre-especifica??o (o numero de classes pode crescer, com os rotulos de classe sendo adicionados pelo processo de aprendizagem on-line), de maneira n~ao-supervisionada. Nos casos em que uma base de regras inicial existe, AutoClass pode evoluir/desenvolver-se a partir dela, baseado nos dados adquiridos posteriormente. De modo a validar a proposta, o trabalho apresenta resultados experimentais de simula??o e de aplica??es industriais reais, onde o sinal de controle e erro s?o utilizados como caracter?sticas para os estagios de detec??o e identifica??o, porem a abordagem e generica, e o numero de caracter?sticas selecionadas pode ser significativamente maior, devido ? metodologia computacionalmente eficiente adotada, uma vez que calculos mais complexos e armazenamento de dados antigos n?o s?o necess?rios. Os resultados obtidos s?o signifificativamente melhores que os gerados pelas abordagens tradicionais utilizadas para compara??o
Arafat, AKM. "ANALYSIS AND CONTROL OF FIVE-PHASE PERMANENT MAGNET ASSISTED SYNCHRONOUS RELUCTANCE MOTOR DRIVE UNDER FAULTS." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1524168102423576.
Повний текст джерелаBousghiri, Souad. "Diagnostic de fonctionnement des procédés continus par réconciliation d'état généralisé : application à la détection de pannes de capteurs et d'actionneurs." Nancy 1, 1994. http://www.theses.fr/1994NAN10396.
Повний текст джерелаLemarchand, Antoine. "Modélisation multi-modèle incertaine du trafic routier et suivi robuste de profils optimaux aux entrées des voies périurbaines." Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENT117/document.
Повний текст джерелаThis document synthesizes my Phd thesis work in Automatic Control in Grenoble-INP. This thesis has been prepared in the automatic control department of thelaboratory GIPSA-lab. This work is situated in the area of traffic systems control andsupervision. Our contributions are about modeling, supervision and local traffic control.The CTM traffic model has been extended with a model of uncertainties. Thisnews model allows us to take into account the uncertain parameters of the model, topropose new robust switched control law.In addition to this modeling approach, we propose some developments on supervisionof trafic systems. On one hand, we can estimate the operating mode of thesystem in real time and on the other hand to estimate some faults on the system. Thedynamical estimation of the operating mode allows us to know the state of congestion(or non congestion) of the road. We are able to estimate faults such as speed fall andcapacities drop that may appear.Finally, we propose two control laws based on switching systems control. The developedcontrollers adapt their geometry to the properties of the system. The purposeof these controllers is to be inserted in a hierarchic control scheme
Amri, Mohamed-Hédi. "Fusion ensembliste de donn´ees pour la surveillance des personnes d´ependantes en habitat intelligent." Thesis, Orléans, 2015. http://www.theses.fr/2015ORLE2030/document.
Повний текст джерелаOur research work is a part of the project FUI 14 FEDER Collectivités E-monitor’âge. This project takes place within the framework of Ambient Assisted Living (AAL) which aims to improve the safety and the comfort of elderly people living in smart nursing homes. This work aims to monitor the activities of elderly persons using information from different sensors. The ADL (Activities of Daily Living) are used to evaluate the ability of the person to perform on their own a selection of the activities which are essential for an independent living in the everyday life. Generally, process knowledge and measurements coming from sensors are prone to indeterminable noise. In our work, we suppose that these errors are unknown but bounded. Taking into account this hypothesis, we show how to solve the estimation issue using set-membership computations techniques. Our algorithm, based on set-membership approach, consists of two steps. The prediction step, based on the use of a random walk mobility with minimum assumptions (maximum speed of moving), employs the previous state estimate to provide the prediction zone where the person may be located. The correction step uses the informations coming from the sensors to refine this predicted zone. This step uses a relaxed constraints propagation technique, q-relaxed intersection, to deal with faulty measurements. This proposed method allows us to compute the uncertainty domain for the reconstructed localization of moving targets as dealing with outliers
Cannon, Brandon Jeffrey. "Fault Detection for Unmanned Aerial Vehicles with Non-Redundant Sensors." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5308.
Повний текст джерелаWang, Hao. "Two-Stage Fault Location Detection Using PMU Voltage Measurements in Transmission Networks." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/54565.
Повний текст джерелаMaster of Science
Rostaing, Gilles. "DIAGNOSTIC DE DÉFAUT DANS LES ENTRAINEMENTS ÉLECTRIQUES." Phd thesis, Grenoble INPG, 1997. http://tel.archives-ouvertes.fr/tel-00909645.
Повний текст джерелаAit, Ladel Ayyoub. "Commande tolérante aux défauts des systèmes à multimodèles : application à des systèmes à multi-source d'énergie." Electronic Thesis or Diss., Aix-Marseille, 2022. http://theses.univ-amu.fr.lama.univ-amu.fr/220330_AITLADEL_882kmyqu655hkbca383zrkcz402ihwf_TH.pdf.
Повний текст джерелаThis thesis deals with the fault detection/estimation and fault-tolerant control challenges through integrated design. The aim is to design control strategies able to maintain robust and acceptable performance even in the presence of faults. The considered systems are dynamic in nature and are multi-model. The approaches proposed in this thesis consist in formalizing the integrated design of the detection/estimation and fault-tolerant control units in the form of linear matrix inequalities to overcome the difficulty posed by the observer/controller coupling. These approaches provide the ability to consider the different interactions between the system, the detection/estimation unit, and the control unit. Therefore, ensuring a global stability analysis of the closed-loop system and robust performances in terms of detection/estimation, control, and fault compensation. The thesis is mainly composed of three parts. In the first part, results on the control in the presence of sensor or actuator faults are established for switched linear systems. In the second part, extensions to switched nonlinear systems with sensor and actuator faults are proposed. Finally, the third part consists of a complete study of a renewable energy system. It is a multi-source/multi-load system designed to meet multiple demands and is subject to the intermittency of renewable energies
Abdellatif, Meriem. "Continuité de service des entraînements électriques pour une machine à induction alimentée par le stator et le rotor en présence de défauts capteurs." Thesis, Toulouse, INPT, 2010. http://www.theses.fr/2010INPT0107/document.
Повний текст джерелаThe development of closed loop controls for electrical drives requires the sensor installations in order to get feed back information. Nevertheless, any occurred sensor fault (current sensor,speed/position sensor,…) shows an operation system deterioration which leads in most cases to its shut down. This consequence is in contrast to industrial expectations especially concerning the system high accuracy that they are asking for. Statistic studies point out the sensor faults as frequent. So, it is necessary to find out solutions ensuring the system service continuity in case of any sensor fault. Firstly, the study presented in this work shows the used sensor technologies in order to understand both of the reason and the kind of occurred faults. Secondly, the studied system is presented which is an electrical drive based on a Doubly Fed Induction Machine (DFIM) operating in motor mode and connected to the grid by two inverters. The control developed is a Direct Torque Control (DTC). The control validation, in healthy operating mode, is realised throw simulation and experimentally. After, a study considering alternative current sensor and speed/position sensor faults are achieved. The developed algorithms are based on signal estimation, on a Fault Detection Isolation (FDI) and reconfiguration algorithms. In fact, they are simple to carry out, they don't need much hardware resources for implementation and their execution time is short. Finally, the experimental validation of the developed algorithms shows their efficiency. The system continues working even in presence of a sensor fault. Thus, the obtained control becomes a fault tolerant control thanks to these algorithms
Chiarello, Andre Garcia. "Detecção e localização de falhas em sistemas mecanicos estacionarios atraves de funções de correlação." [s.n.], 1998. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265204.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: Este trabalho aborda o problema de detecção e localização de falhas em sistemas mecânicos através de modelos matemáticos. Considera-se que o sistema mecânico seja representado por um modelo dinâmico na forma de variáveis de estado, com parâmetros constantes e entradas estacionárias. Definindo-se, apropriadamente, funções de correlação e explorando as propriedades inerentes aos sistemas estacionários, consegue-se obter funções analíticas envolvendo parâmetros físicos do sistema. Posteriormente, demonstra-se que estas funções analíticas podem ser utilizadas para monitorar parâmetros físicos do modelo, ou ainda, identificar parâmetros físicos relacionados a uma falha no sistema. Duas abordagens diferentes para o problema de localização de falhas são desenvolvidas: uma utiliza a estimação de parâmetros e outra utiliza funções de resíduo. Visando uma aplicação em sistemas reais, foram simulados sistemas mecânicos em diversas condições de operação. Os resultados numéricos comprovaram que a metodologia proposta pode ser utilizada no monitoramento de sistemas mecânicos
Abstract: This work deals with the problem of fault detection and location in mechanical systems through mathematical models. It is considered that the mechanical system is represented in a state space form, with constant parameters and stationary inputs. Some correlation functions are appropriately defined involving physical parameters of the stationary system. It is demonstrated that these correlation functions can be transformed to appropriate analytical form (redundancy equations) for fault detection and isolation purposes. Two different approaches are considered: one based on physical parameters estimation and the other based on residuaIs generation. Three different mechanical systems were numerically simulated with conditions (or restrictions) usually found in practical situations. The results showed that the proposed approach is a promising methodology for monitoring stationary mechanical systems
Doutorado
Projeto Mecanico
Doutor em Engenharia Mecânica
Song, Ruixiang. "Parameter estimation based fault detection and isolation in electrohydraulic systems." 2002. http://hdl.handle.net/1993/19715.
Повний текст джерелаChang, Der-Shing, and 張德賢. "State Estimation and Fault Detection Bases on Hybrid Neural Network." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/40527711031314796304.
Повний текст джерела國立臺灣科技大學
化學工程研究所
83
The hybrid neural network of Tung et al. (1995) is extended to multivariable systems. Since the architecture of the hybrid network is similar to that of Kalman filter,all states of nonlinear systems can be reconstructed once some measurments are measurable. If all states are measurable, it then becomes the problem of data rectification. Comparison is made between nthe hybrid network and Elman net. The results show that for the trained noise level, the hybrid net is comparable to the Elman net.Hower,the proposed hybrid net shows better adaptability on the noise level changes. If some of the states are unmeasurable, the hybrid network naturally leads to an partial recurrent and partial mixed recurrent plus feedforward architecture.More import retains good state estimation with few output measurements corrupted with measurement noise. The state estimation capability of the hybrid network leads it to be a natural fault detection system. The fault origins can be viewed as unmeasured state and they can be estimated from process measurements.A CSTR example is used to illustrate the effectiveness of the neural fault detector. Simulation results show that the proposed system can defect the fault effectively under single or multiple faults . More importantly, it gives very good tracking as the faults develop.
Labuschagne, Petrus Jacobus. "Automatic clustering with application to time dependent fault detection in chemical processes." Diss., 2009. http://hdl.handle.net/2263/26092.
Повний текст джерелаDissertation (MEng)--University of Pretoria, 2009.
Chemical Engineering
unrestricted
Nakhaeinejad, Mohsen. "Fault detection and model-based diagnostics in nonlinear dynamic systems." Thesis, 2010. http://hdl.handle.net/2152/ETD-UT-2010-12-2208.
Повний текст джерелаtext
Serpas, Mitchell Roy. "Soft Sensors for Process Monitoring of Complex Processes." Thesis, 2012. http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11639.
Повний текст джерелаSantos, Inês Vilela dos. "Towards a predictive maintenance methodology of hydraulic pumps." Master's thesis, 2021. http://hdl.handle.net/10773/31362.
Повний текст джерелаAs bombas hidráulicas, elementos essenciais nos sistemas de abastecimento de água, são os principais responsáveis pelos elevados consumos energéticos associados a estes sistemas. Torna-se, portanto, relevante manter as bombas a funcionar nas suas melhores condições possíveis de forma a evitar mais consumos e custos, e também antecipar possíveis falhas nas bombas. A melhor estratégia para antecipar o acontecimento de falhas passa pela implementação de planos de manutenção preventivos e preditivos, ao invés da manutenção corretiva que é ainda muito aplicada. Assim, com vista ao desenvolvimento de uma metodologia de manutenção preditiva aplicada às bombas hidráulicas, esta dissertação tem como objetivo a exploração e investigação da aplicabilidade de duas técnicas que podem ser integradas num plano de manutenção: a deteção e classificação de falhas e a estimativa do tempo de vida útil restante (RUL) de uma bomba. Para implementar as tarefas propostas utilizaram-se dados simulados e dados medidos a partir de sistemas reais, retirados de repositórios de dados online, com valores registados por sensores e com a condição do sistema identificada. A primeira técnica permitiu, através de dados de sensores com as respetivas falhas identificadas, treinar algoritmos de classificação capazes de identificar falhas. No primeiro dos casos de estudo avaliados, o melhor dos algoritmos implementados identificou as falhas associadas aos dados da bomba com uma classificação de desempenho de 82.9%, ao passo que, no segundo dos casos de estudo avaliados, o algoritmo que apresentou melhor desempenho obteve uma classificação de 94.6% na identificação do modo de falha associado à bomba. Os algoritmos de decision trees e ensemble trees demonstraram ser os mais indicados para o propósito estudado. A segunda técnica permitiu calcular previsões de valores do RUL a partir de dados de sensores registados desde uma operação normal até à falha do sistema. Apesar de o primeiro caso de estudo de implementação de RUL ter sido um motor, o segundo caso de estudo foi uma bomba de água. A metodologia do modelo de RUL demonstrou ser pertinente pois conseguiu, ainda que com alguns desvios em relação aos verdadeiros valores, estimar valores aceitáveis de RUL. Elaborou-se ainda uma análise económica que evidencia a relevância em aplicar modelos de cálculo de RUL em metodologias de manutenção preditiva de bombas hidráulicas
Mestrado em Engenharia Mecânica
Suryawan, Fajar. "Constrained trajectory generation and fault tolerant control based on differential flatness and B-splines." Thesis, 2011. http://hdl.handle.net/1959.13/927247.
Повний текст джерелаThis thesis provides a unified treatment of the notions of differential flatness, for the characterisation of continuous-time linear systems, and B-splines, a mathematical concept commonly used in computer graphics. Differential flatness is a property of some controlled (linear or nonlinear) dynamical systems, often encountered in applications, which allows for a complete parameterisation of all system variables (inputs and states) in terms of a finite number of variables, called flat outputs, and a finite number of their time derivatives. The notion of differential flatness for a system is especially useful in situations when explicit trajectory generation is required. In fact, under the differential flatness formalism the motion planning problem, as far as the differential equation is concerned, is trivialised. However, a very important limitation, ubiquitous in all practical applications, is the presence of constraints. The problem of constrained trajectory generation is intimately related to that of optimal control, where one wants to achieve certain objectives with limited resources, and time-optimal control, in which one seeks to perform a task as fast as possible while, at the same time, satisfying all system constraints. In the literature, trajectory generation and [time-] optimal control often use some parameterisation to represent the system's signals. Polynomials and B-splines are a natural choice since they have several desirable properties. However, there has not been much work exploiting the combined properties of differential flatness for linear systems and B-splines. The first focus of this thesis is, hence, to investigate the use of B-splines for constrained trajectory generation of continuous-time linear flat systems in such a way that their respective properties are jointly exploited and complemented. This synthesis offers new methods and insights to the fields of constrained trajectory optimisation, optimal control, and minimum-time trajectory generation. The differential flatness parameterisation also offers analytical redundancy relations. That is, the value of some variables can be algebraically inferred from some other measured variables. This fact can be used to perform algebraic estimation and fault detection in linear and nonlinear systems. The second focus of this thesis is, thus, to develop a method to perform algebraic estimation and fault detection, based structurally on the differential flatness notion, for linear and nonlinear systems, and using a numerical method based on B-splines. The methodology to tackle the focal problems of constrained trajectory generation and fault tolerant control, based on differential flatness and B-splines, is primarily developed for linear systems. Then, experimental validations of the methods, using a laboratory-scale magnetic levitation system, are provided. Finally, some extensions of the ideas to nonlinear systems are discussed.
(9754367), Pallavi Madhav Kulkarni. "Contributions to Autonomous Operation of a Deep Space Vehicle Power System." Thesis, 2020.
Знайти повний текст джерелаLukic, Zdravko. "Design and Practical Implementation of Advanced Reconfigurable Digital Controllers for Low-power Multi-phase DC-DC Converters." Thesis, 2012. http://hdl.handle.net/1807/33855.
Повний текст джерела