Frédéric Kratz

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• Professor
• Professor at Institut National des Sciences Appliquées Centre Val de Loire

Objective: The objective of this study is to investigate [insert specific research topic here], with the aim of [briefly explain the main purpose of the research]. Theoretical Framework: The supply-side performance of Islamic Higher Education (IHE) is linked to its potential output, representing the maximum sustainable production. The SDG goal of Q...

In the dynamic aviation industry, Aerospace Industries grapple with the intricate challenge of certifying products amidst integration requirements from aerospace manufacturers and airworthiness regulations imposed by aviation authorities. This paper underscores the indispensable role of ModelBased Systems Engineering (MBSE) in addressing the multip...

An efficient maintenance policy allows for determining the current state of a system (diagnosis phase) and its future state (prognosis phase). We show in this paper that Markovian methods allow for obtaining many efficient indicators for the expert. To characterize the quality and robustness of these methods, we compared the Hidden Semi-Markov Mode...

With the implementation of the industry of the future, also called “Industry 4.0”, digital technology, a virtual or non-virtual confluence of data, software, sensors, actuators, and effectors, different networks of technologies have had to be put in place. The arrival of the Industrial Internet of Things (IIoT) for Industry 4.0 participates in a tr...

New professions, emerging skills, and the employability of students in the digital economy are among the key issues that must be addressed for university education to become more proactive. Companies expect our courses to be effective, combining a variety of skills as needed: management knowledge, specialization in a particular profession, soft ski...

This paper presents the development of a new algorithm for the diagnosis of induction motor inter-turn short circuit and mixed combined fault detection based on the reduction Park’s vector modulus and discrete wavelet transform. The proposed method is based on a combination between the RPVM approach and DWT. This new signal of the RPVM is a cost-ef...

The designation of dynamic parameters of robots is generally based on the use of the inverse model which is linear with respect to the dynamic parameters to be identified. In order to obtain an undetermined system, this model is sampled while the robot is driven with exciting movements. The optimum solution is obtained using the least linear square...

The present paper addresses a precise and an accurate mathematical model for three-phase squirrel cage induction motors, based on winding function theory. Through an analytical development, a comparative way is presented to separate the signature between the existence of the outer race bearing fault and the static eccentricity concerning the asymme...

Purpose The purpose of this paper is to propose applications of advanced signal-processing techniques for the diagnosis and detection of rotor fault in an induction machine. Two techniques are used: spectral analysis techniques and time frequency techniques for the diagnosis of an electrical machine. One is based on the power spectral density estim...

This paper investigated the ability of the diagnosis techniques and detectability of induction motor faults through a stator current. The proposed techniques are based on advanced signal processing tools. These methods can be classified into: high resolution approaches and time–frequency representations. Sadly, the Fast Fourier transform technique...

Maintaining substantial mobility is essential for those who suffer from reduced mobility to regain their independence in daily motion tasks. In recent years, robotic solutions to human mobility aid have been functionally verified by various applications. Moreover, with the emergence of new robots and systems, the robot design theory is also under r...

The increasing complexity of industrial processes, the continuing search for higher profits, and increasingly demanding production constraints call for the implementation of a proactive and sustainable maintenance policy. Adapting maintenance policies that integrate the concepts and obligations of so-called sustainable development is a real challen...

We propose an approach for failure prognosis based on the estimation of the Remaining Useful Life (RUL) of a system in a situation in which monitoring signals providing information about its degradation evolution are not measured and no operating model of the system is available. These conditions are of practical interest for industrial application...

Learning strategies like integrating Islamic values into learning can be applied to improve learning outcomes. Integrating Islamic values into learning science and technology provides opportunities for students to integrate science and technology with concepts and experiences in real life as Muslims so that they can feel that their learning is mean...

In this article, we propose a practical prognosis approach. It estimates online the remaining duration of the system before the system performance requirements are no longer met to fulfill a specific mission. The systems targeted by this approach have the particularity of a lack of measuring instruments capable of providing indications of potential...

In this paper, a robust finite memory observer has been developed for the continuous-discrete linear time-varying (CD-LTV) systems, which are modeled by the ordinary differential equations (ODEs) in the presence of process noise and are observed through discrete noisy measurements. The proposed method collects a finite number of noisy measurements...

This paper intends to design a continuous-discrete unknown input finite memory observer (CD-UI-FMO) for the dynamical nonlinear systems with unknown input. The nonlin-ear systems under consideration are at least locally Lipschitz and represented by ordinary differential equations (ODEs) with process noise while measurements are sampled at discrete...

The diagnosis of electrical motor for broken rotor bars faults through frequency signatures of the stator current method has been widely explored. In fact, a high‐resolution spectrum analysis based on the multiple signal classification (MUSIC) method has been widely applied to detect induction machine faults for that purpose. Moreover, MUSIC is a p...

This paper aims to develop a continuous-discrete finite memory observer (CD-FMO) for a class of nonlinear dynamical systems modeled by ordinary differential equations (ODEs) with discrete measurements. The nonlinear systems under consideration are at least locally Lipschitz, which guarantees the existence and uniqueness of solution at each time ins...

The study focuses on the design of a diagnosis tool to detect a content modification attack of an uncertain network control system. In the litterature, a content modification attack is designed to produce trajectory modification on tele-operated systems by modifying data transmitted through a network. Attack is difficult to detect because modificat...

Les processus ou systèmes industriels deviennent de plus en plus complexes et il est aujourd'hui très important de pouvoir assurer un fonctionnement efficace à ces processus. En effet, tout dysfonctionnement va entraîner une consommation inutile de matière première et d'energie. De manière à conserver sa compétitivité, toute installation se doit de...

Many papers have been written on financial indicators to assess the use of a maintenance policy based on Total Productive Maintenance, while others have compared results showing the impact of criteria such as the Mean Time Between Failures. This paper provides the maintenance managers indicators which can assess the relevance of the actions carried...

Parmi les nombreuses stratégies pédagogiques permettant d’améliorer la motivation, le savoir-être et le savoir-faire des élèves ou des étudiants, la pédagogie par projet est souvent citée comme exemple. C’est dans ce contexte, qu’un challenge intitulé « L’industrie du futur, c’est maintenant ! » a été activé en 2018 pour des élèves ingénieurs de sp...

In principal component analysis (PCA) based fault detection and isolation (FDI), the sensor data uncertainties cause a significant difficulty in control decision making, which evokes and increases the number of false alarms and imprecise decisions. In its standard form, PCA makes no distinction between data points and the associated measurement err...

In this paper, we propose a sensorless approach for failure prognosis. The approach deals with nonlinear Multiple-Input Multiple-Output system subject to degradations. The aim of this work was to estimate online the duration before the system performance requirement is no longer met, this without adding sensors. To carry out this aim, we used a Non...

This paper presents the development of a Finite Memory Observer in systems with a correlation between measurement and state noises. This work proves the interest of designing observer statements adapted to systems with correlated noises. It also develops a theoretical form of continuous time representation of Finite Memory Observers. The estimators...

Principal component analysis (PCA) based fault detection and isolation (FDI) is a well established data-driven diagnosis strategy that has long been praised for its performances. However, it is still not optimal for uncertain systems, mainly since the model uncertainties usually have a significant effect on the reliability of the method. As an alte...

Le problème traité dans cet article concerne la modélisation en vue du diagnostic des systèmes dynamiques incertains en utilisant l'analyse en composantes principales (ACP) intervalle. Le principe de base consiste à étendre les techniques de l'ACP à des données de type intervalle. L'approche de modélisation utilisée est dite méthode des centres et...

This paper presents a new approach to estimate states and parameters of the permanent magnet synchronous motor (PMSM) in the presence of unknown load torque disturbance. Indeed, it highlights an auxiliary dynamics that is added to the PMSM model. Thereby, it supplies a change of coordinates that transforms the extended model (PMSM model together wi...

This study presents a new approach to estimate states and parameters of the permanent magnet synchronous motor (PMSM) in the presence of unknown load torque disturbance. Indeed, it highlights an auxiliary dynamics that is added to the PMSM model. Thereby, it supplies a change of coordinates that transforms the extended model (PMSM model together wi...

Depuis quelques années, une des thématiques de recherche développée dans le laboratoire PRISME en collaboration avec des partenaires industriels locaux concerne l’estimation du niveau de dégradation d’un processus à l’aide d’un Modèle de Markov Caché (MMC) à partir des informations issues du service de maintenance. Pour cela, l’accès aux données as...

The next generation of telesurgical robotics systems presents significant challenges related to network performance and data security. It is known that packet transmission in wide area networks is a complex stochastic process; thus, low bandwidth as well as high delay, jitter, and packet loss will greatly affect the quality of service (QoS) of tele...

In the past years, Hidden Markov Models have been used in several fields and applications with success. More recently, these models have been applied to improve the reliability of a machinery system. In many cases, failure is preceded by specific sequences of events (signature), which can be detected by an adequate Hidden Markov Model (HMM). Classi...

This paper deals with the problem of adaptive observer-based synchronization of chaotic dynamical systems. The proposed approach consists in estimating the states and the unknown parameters in a separate way to reduce computational requirements. A rigorous stability analysis is performed and a judicious parametrization of the algorithm is proposed...

In this paper the state reconstruction problem for a class of nonlinear systems is considered and the question of convergence of the estimation error is examined. The main result is a new upper bound of the Lipschitz constant. Bounds of the free parameters are given so that the asymptotic stability of the observer is guaranteed. The proposed observ...

Nous proposons dans cet article une approche d'identification du niveau de dégradation d'un système. L'objectif est de proposer une démarche de modélisation permettant de déterminer le niveau de dégradation atteint par le système. La démarche proposée consiste à utiliser le formalisme de Modèle de Markov Caché (MMC) multi-flux sur des séquences obt...

Les modèles de Markov cachés ou HMM 1 sont largement utilisés dans les domaines de la reconnaissance des formes, de la parole ainsi que dans la modélisation de processus complexes. Nous proposons dans cette étude d'évaluer la pertinence des paramètres de modèles de Markov cachés de façon objective sans connaissance a priori. Nous présentons des cri...

This paper focuses on the states estimation and parameter identification for nonlinear Dengue epidemic model. This model supplies a change of coordinates that transforms the studied model into an extended output depending nonlinear observer normal form. Then we can use the high gain observer strategy, which allows both the parameter identification...

This article deals with modelization of industrial process by using hidden Markov model. The process is seen as a discrete event system. We propose different structures based on Markov automata, called topologies. A synthetic hidden Markov model is designed in order to match to a real industrial process. The models are intended to decode industrial...

This paper uses the Hidden Markov Model to model an industrial process seen as a discrete event system. Different graphical structures based on Markov automata, called topologies, are proposed. We designed a Synthetic Hidden Markov Model based on a real industrial process. This Synthetic Model is intended to produce industrial maintenance observati...

Prediction of physical particular phenomenon is based on partial knowledge of this phenomenon. Theses knowledges help us to conceptualize this phenomenon according to different models. Hidden Markov Models (HMM) can be used for modeling complex processes. We use this kind of models as tool for fault diagnosis systems. Nowadays, industrial robots li...

Dans ce papier, nous utilisons les Modèles de Markov Cachés comme outils de diagnostic dans l'aide à la décision en maintenance industrielle. En effet, les chaines de fabrication industrielles utilisent une robotisation de plus en plus pointue. Seulement, les politiques de maintenance ne sont pas adaptées aux attentes de compétitivité exigées. Notr...

Prediction of physical particular phenomenon is based on knowledges of the phenomenon. Theses knowledges help us to conceptualize this phenomenon throw different models. Hidden Markov Models (HMM) can be used for modeling complex processes. We use this kind of models as tool for fault diagnosis systems. Nowadays, industrial robots living in stochas...

Today, maintenance strategies and their analyses remain a worrying problem for companies. Socio-economic stakes depending on the competitiveness of each strategy are more than ever linked to the activity and quality of maintenance interventions. A series of specific events can eventually warn the expert of an imminent breakdown. This study aims at...

Les stratégies de maintenance et leurs évaluations demeurent une préoccupation particulièrement forte au sein des entreprises aujourd'hui. Les enjeux socio-économiques dépendant de la compétitivité de chacune d'entre elles sont de plus en plus étroitement liés à l'activité et à la qualité des interventions de maintenance. Une suite d'évènements par...

De nos jours, les stratégies de maintenance et leurs évaluations demeurent une préoccupation particulièrement forte au sein des entreprises. Une suite d'évènements particuliers peut, éventuellement, informer l'expert d'une panne prochaine. Notre étude tente d'appréhender " cette signature " à l'aide de modèles de Markov cachés. Nous proposons à l'e...

Today, maintenance strategies and their analyses remain a worrying problem for companies. A series of specific events can potentially warn the expert of an imminent breakdown. Our study aims at understanding this "signature" thanks to hidden Markov model. On that purpose, two methods on damage level estimation of a maintained system are proposed to...

CNRIUT, Colloque National de la Recherche en IUT

This article follows a line of papers focused on defining a method to improve the realization of reliability analysis during the System Engineering process. As MBSE becomes a fundamental concept for specifying and designing systems, our method takes full advantages of this approach and try to provide tools to ease the specification stage and the in...

This article proposes a triangular canonical form for a class of 0-flat nonlinear systems. Necessary and sufficient geometrical conditions are given in order to guarantee the existence of a local diffeomorphism to transform the studied nonlinear systems into the proposed 0-flat canonical form, which enables us to compute the flat output as well.

This article proposes a generative approach to decision making in a complex and uncertain environment, as an alternative to normative or descriptive approaches. A simple and intuitive graphical model provides management teams with a non-restrictive framework for thinking through their decisions. The second half of the article proposes a mathematica...

This paper deals with a tool which may help maintenance manager to schedule maintenance activities. To help him, we show that by using events which can be observed on a process, like maintenance events, we can predict failures before they occur. Principles are based on the hypothesis that failure is preceded by a typical sequence of events. We also...

This paper deals with a tool which may help maintenance managers to schedule maintenance activities. To help them, we show that by using events which can be observed on a process, like maintenance events, we can predict failures before they occur. Principles are based on hypothesis that failure is preceded by a typical sequence of events. We also s...

The different algorithm of data classification and clusterisation to identify the subject on the room is introduced. The aim is to provide a learning approach for pattern classification of presence sensors data. The focus of the system is on its application to find the best method for identification the subject location using a specific category da...

Sections de rattachement : 61 Secteur : secondaire RÉSUMÉ. Les modèles de Markov Cachés ou HMM 1 peuvent être utilisés pour la modélisation de processus complexes. Dans cette étude, nous souhaitons évaluer la pertinence des paramètres d'un modèle de façon objective sans connaissance à priori. Dans un premier temps, nous présentons les critères de s...

IntroductionInternal model controllerPredictive controlSliding controlBang-bang controlControl-based fuzzy logicNeural network controlBibliography

IntroductionPID controllersPID controllersMethods based on previous knowledge of a system modelOptimal controlChoice of a controlBibliography

This paper deals with a tool which may help maintenance manager to schedule maintenance activities. To help him, we show that by using events which can be observed on a process, like maintenance events, we can predict failures before they occur. Principles are based on the hypothesis that failure is preceded by a typical sequence of events. We also...

This paper is devoted to the study of nonlinear observer design for state estimation and parameter estimation of discrete-time nonlinear systems. The observer is an extension into MIMO case of that presented by Cicarella et al. The convergence of this observer is demonstrated and an example illustrates its performances.

This work presents a novel algorithm for the invertibility of switched nonlinear systems. An invertible switched system is one for which it is possible to reconstruct the entire unknown inputs and the associated evolving mode. In our approach, the dynamic of the inverse systems is given by means of a projection which decomposes the state space into...

This paper gives the sufficient and necessary conditions to guarantee the existence of a linear change of coordinates to transform a multi-output linear dynamical system (modulo a nonlinear term depending on inputs and outputs) in the observability Brunovsky canonical form.

This paper gives a description of a class of 0-flat dynamical systems. This class is characterized by the involutivity of a distribution associated naturally to multi-output affine dynamical systems and the Lie bracket of some control vector fields fulfilling some conditions. We will also show that these conditions are a generalization of the well-...

d'Ingénieurs 88 boulevard lahitolle 18020 Bourges cedex Pascal.Vrignat@univ-orleans.fr ; Manuel.Avila@univ-orleans.fr ; Florent.Duculty@univ-orleans.fr ;Bernard.Robles@univ-orleans.fr frederic.kratz@ensi-bourges.fr Sections de rattachement : 61 Secteur : Secondaire RÉSUMÉ. Cet article tente de montrer qu'il est possible de « qualifier » les activit...

In this paper, we introduce a methodology for the reliability analysis of complex systems during their design. The challenge of such a method is to be efficient and accessible for system engineers. We gear this method towards the reuse of functional models expressed in the widely used languages of OMG (Object Management Group). We discuss the impro...