Download or read book Diagnostic des engrenages et des roulements par une analyse vibratoire en r gime variable written by Amadou Assoumane and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Depuis une dizaine d'années, plusieurs méthodes de traitement du signal vibratoire ont été développées pour le diagnostic des machines tournantes en régime stationnaire. Or, de plus en plus de machines sous surveillance fonctionnent en régime variable telles que les éoliennes, les concasseurs, etc... Les méthodes développées pour la surveillance et le diagnostic de ces machines en régime stationnaire ne sont plus adaptées en régime variable. Certains outils proposés pour le régime variable sont limités à des applications bien spécifiques ou offrent un cadre théorique qui limite leur utilisation dans les situations réelles. Le but de cette thèse est justement de pallier ces limitations, et ce, en proposant une nouvelle approche permettant d'analyser les signaux vibratoires acquis en régime variable. La stratégie mise en oeuvre dans cette thèse repose sur une modélisation du signal vibratoire dans l'espace d'état et une estimation H∞ des grandeurs caractéristiques de l'état de fonctionnement de la machine. Tout d'abord, nous avons décrit le signal vibratoire dans l'espace d'état grâce à une projection de l'enveloppe de chaque composante fréquentielle du signal sur la base canonique orthogonale. Ensuite, nous avons proposé une estimation de l'enveloppe. Cette approche d'estimation repose sur une optimisation minimax et consiste à minimiser le maximum de l'erreur d'estimation sans faire d'hypothèse sur la nature statistique des bruits du modèle d'état. Cette stratégie a conduit à ce que nous avons appelé dans cette thèse 'estimateur BCOH∞'. La nouvelle approche proposée a été appliquée à des signaux synthétiques et expérimentaux pour le diagnostic de l'état des engrenages et des roulements en régime variable.
Download or read book Electrical Systems 1 written by Abdenour Soualhi and published by John Wiley & Sons. This book was released on 2020-04-09 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods of diagnosis and prognosis play a key role in the reliability and safety of industrial systems. Failure diagnosis requires the use of suitable sensors, which provide signals that are processed to monitor features (health indicators) for defects. These features are required to distinguish between operating states, in order to inform the operator of the severity level, or even the type, of a failure. Prognosis is defined as the estimation of a system's lifespan, including how long remains and how long has passed. It also encompasses the prediction of impending failures. This is a challenge that many researchers are currently trying to address. Electrical Systems, a book in two volumes, informs readers of the theoretical solutions to this problem, and the results obtained in several laboratories in France, Spain and further afield. To this end, many researchers from the scientific community have contributed to this book to share their research results.
Download or read book Diagnostic vibratoire autonome des roulements written by Souhayb Kass and published by . This book was released on 2019 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Le monde de l'industrie et des transports dispose de machines et d'installations de plus en plus performantes et complexes. Ils ne peuvent être exempts de perturbations et de défaillances, influant sur la qualité du produit, pouvant provoquer l'arrêt immédiat d'une machine et porter atteinte au bon fonctionnement d'un système de production entier. Le diagnostic de ces machines, s'appuie essentiellement sur la surveillance de symptômes liés à différentes conditions de dégradation. Ces symptômes peuvent être tirés de diverses sources d'information, parmi lesquelles l'analyse vibratoire et acoustique occupe une place prépondérante. Aujourd'hui, de nombreuses techniques efficaces sont bien établies, ancrées sur des outils puissants offerts notamment par la théorie des processus cyclostationnaires. La complexité de ces outils exige un expert pour les utiliser et les interpréter. La présence continue d'un expert est difficilement réalisable et couteuse. Des indicateurs d'état de machines tournantes existent dans la littérature mais ils sont conçus sous l'hypothèse de conditions de fonctionnement parfaites. Ces travaux restent limités, dispersés et généralement non soutenus par des cadres théoriques. Le principal objectif de cette thèse est de réduire le recours à l'intervention humaine en proposant des stratégies pour concevoir deux indicateurs optimaux qui résument l'information de diagnostic en une valeur scalaire. Ces stratégies sont élaborées en distinguant deux familles dans le diagnostic : le cas où les informations sur les défauts sont connues et celle où elles sont inconnues. Ces indicateurs sont destinés à être utilisés dans le cadre d'un processus de diagnostic autonome, sans nécessiter d'intervention humaine, à l'aide des tests d'hypothèses statistiques. La capacité de ces indicateurs est validée sur des données réelles et comparée avec d'autres indicateurs de la littérature en termes de performance de détection.
Download or read book D tections des d fauts dans les roulements par l analyse vibratoire written by Jean-Luc Dallest and published by . This book was released on 1997 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrical Systems 1 written by Abdenour Soualhi and published by John Wiley & Sons. This book was released on 2020-06-03 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods of diagnosis and prognosis play a key role in the reliability and safety of industrial systems. Failure diagnosis requires the use of suitable sensors, which provide signals that are processed to monitor features (health indicators) for defects. These features are required to distinguish between operating states, in order to inform the operator of the severity level, or even the type, of a failure. Prognosis is defined as the estimation of a systems lifespan, including how long remains and how long has passed. It also encompasses the prediction of impending failures. This is a challenge that many researchers are currently trying to address. Electrical Systems, a book in two volumes, informs readers of the theoretical solutions to this problem, and the results obtained in several laboratories in France, Spain and further afield. To this end, many researchers from the scientific community have contributed to this book to share their research results.
Download or read book Fans and Ventilation written by William Cory and published by Elsevier. This book was released on 2010-07-07 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: The practical reference book and guide to fans, ventilation and ancillary equipment with a comprehensive buyers' guide to worldwide manufacturers and suppliers. Bill Cory, well-known throughout the fans and ventilation industry, has produced a comprehensive, practical reference with a broad scope: types of fans, how and why they work, ductwork, performance standards, testing, stressing, shafts and bearings. With advances in technology, manufacturers have had to continually improve the performance and efficiency of fans and ventilation systems; as a result, improvements that once seemed impossible have been achieved. Systems now range in all sizes, shapes, and weight, to match the ever increasing applications. An important reference in the wake of continuing harmonisation of standards throughout the European Union and the progression of National and International standards. The Handbook of Fans and Ventilation is a welcome aid to both mechanical and electrical engineers. This book will help you to... •Understand how and why fans work •Choose the appropriate fan for the right job, helping to save time and money •Learn installation, operational and maintenance techniques to keep your fans in perfect working order •Discover special fans for your unique requirements •Source the most appropriate equipment manufacturers for your individual needs - Helps you select, install, operate and maintain the appropriate fan for your application, to help you save time and money - Use as a reference tool, course-book, supplier guide or as a fan/ventilation selection system - Contains a guide to manufacturers and suppliers of ventilation systems, organised according to their different styles and basic principles of operation
Download or read book Examination of a Technique for the Early Detection of Failure in Gears by Signal Processing of the Time Domain Average of the Meshing Vibration written by P. D. McFadden and published by . This book was released on 1986 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: An existing technique for the signal processing to the time domain average of the tooth meshing vibration of gears is examined with application to the early detection of failure. It is shown that the regular signal extracted from the time domain average of the gear vibration by the elimination of the fundamental and harmonics of the tooth meshing frequency forms the time domain average of the vibration of a single tooth. The residual signal which is obtained by subtracting the regular signal from the original time domain average gives the departures of the vibration from the average. Numerical and practical examples are given. (Author).
Download or read book Multiphysics Modelling and Simulation for Systems Design and Monitoring written by Mohamed Haddar and published by Springer. This book was released on 2016-10-08 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reports on the state of the art in the field of multiphysics systems. It consists of accurately reviewed contributions to the MMSSD’2014 conference, which was held from December 17 to 19, 2004 in Hammamet, Tunisia. The different chapters, covering new theories, methods and a number of case studies, provide readers with an up-to-date picture of multiphysics modeling and simulation. They highlight the role played by high-performance computing and newly available software in promoting the study of multiphysics coupling effects, and show how these technologies can be practically implemented to bring about significant improvements in the field of design, control and monitoring of machines. In addition to providing a detailed description of the methods and their applications, the book also identifies new research issues, challenges and opportunities, thus providing researchers and practitioners with both technical information to support their daily work and a new source of inspiration for their future research.
Download or read book Advances in Condition Monitoring of Machinery in Non Stationary Operations written by Anna Timofiejczuk and published by Springer. This book was released on 2017-09-20 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides readers with a snapshot of recent methods for non-stationary vibration analysis of machinery. It covers a broad range of advanced techniques in condition monitoring of machinery, such as mathematical models, signal processing and pattern recognition methods and artificial intelligence methods, and their practical applications to the analysis of nonstationarities. Each chapter, accepted after a rigorous peer-review process, reports on a selected, original piece of work presented and discussed at the International Conference on Condition Monitoring of Machinery in Non-Stationary Operations, CMMNO’2016, held on September 12 – 16, 2016, in Gliwice, Poland. The contributions cover advances in both theory and practice in a variety of subfields, such as: smart materials and structures; fluid-structure interaction; structural acoustics as well as computational vibro-acoustics and numerical methods. Further topics include: engines control, noise identification, robust design, flow-induced vibration and many others. By presenting state-of-the-art in predictive maintenance solutions and discussing important industrial issues the book offers a valuable resource to both academics and professionals and is expected to facilitate communication and collaboration between the two groups.
Download or read book Mechanical Vibration written by and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fault Diagnosis of Induction Motors written by Jawad Faiz and published by IET. This book was released on 2017-08-29 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive, structural approach to fault diagnosis strategy. The different fault types, signal processing techniques, and loss characterisation are addressed in the book. This is essential reading for work with induction motors for transportation and energy.
Download or read book Mechanical Vibration written by William John Palm and published by . This book was released on 2007 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: Model, analyze, and solve vibration problems, using modern computer tools. Featuring clear explanations, worked examples, applications, and modern computer tools, William Palm's Mechanical Vibration provides a firm foundation in vibratory systems. You'll learn how to apply knowledge of mathematics and science to model and analyze systems ranging from a single degree of freedom to complex systems with two and more degrees of freedom. Separate MATLAB sections at the end of most chapters show how to use the most recent features of this standard engineering tool, in the context of solving vibration problems. The text introduces Simulink where solutions may be difficult to program in MATLAB, such as modeling Coulomb friction effects and simulating systems that contain non-linearities. Ample problems throughout the text provide opportunities to practice identifying, formulating, and solving vibration problems. KEY FEATURES Strong pedagogical approach, including chapter objectives and summaries Extensive worked examples illustrating applications Numerous realistic homework problems Up-to-date MATLAB coverage The first vibration textbook to cover Simulink Self-contained introduction to MATLAB in Appendix A Special section dealing with active vibration control in sports equipment Special sections devoted to obtaining parameter values from experimental data
Download or read book Fundamentals of Machine Component Design written by Robert C. Juvinall and published by John Wiley & Sons. This book was released on 2020-06-23 with total page 805 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Machine Component Design presents a thorough introduction to the concepts and methods essential to mechanical engineering design, analysis, and application. In-depth coverage of major topics, including free body diagrams, force flow concepts, failure theories, and fatigue design, are coupled with specific applications to bearings, springs, brakes, clutches, fasteners, and more for a real-world functional body of knowledge. Critical thinking and problem-solving skills are strengthened through a graphical procedural framework, enabling the effective identification of problems and clear presentation of solutions. Solidly focused on practical applications of fundamental theory, this text helps students develop the ability to conceptualize designs, interpret test results, and facilitate improvement. Clear presentation reinforces central ideas with multiple case studies, in-class exercises, homework problems, computer software data sets, and access to supplemental internet resources, while appendices provide extensive reference material on processing methods, joinability, failure modes, and material properties to aid student comprehension and encourage self-study.
Download or read book Contact Mechanics written by K. L. Johnson and published by Cambridge University Press. This book was released on 1987-08-28 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: This treatise is concerned with the stresses and deformation of solid bodies in contact with each other, along curved surfaces which touch initially at a point or along a line. Examples are a railway wheel and rail, or a pair of gear wheel teeth. Professor Johnson first reviews the development of the theory of contact stresses since the problem was originally addressed by H. Hertz in 1882. Next he discusses the influence of friction and the topographical roughness of surfaces, and this is incorporated into the theory of contact mechanics. An important feature is the treatment of bodies which deform plastically or viscoelastically. In addition to stationary contact, an appreciable section of the book is concerned with bodies which are in sliding or rolling contact, or which collide.
Download or read book Observer Design for Nonlinear Systems written by Pauline Bernard and published by Springer. This book was released on 2019-02-01 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observer Design for Nonlinear Systems deals with the design of observers for the large class of nonlinear continuous-time models. It contains a unified overview of a broad range of general designs, including the most recent results and their proofs, such as the homogeneous and nonlinear Luenberger design techniques. The book starts from the observation that most observer designs consist in looking for a reversible change of coordinates transforming the expression of the system dynamics into some specific structures, called normal forms, for which an observer is known. Therefore, the problem of observer design is broken down into three sub-problems: • What are the available normal forms and their associated observers?• Under which conditions can a system be transformed into one of these forms and through which transformation? • How can an inverse transformation that recovers an estimate in the given initial coordinates be achieved? This organisation allows the book to structure results within a united framework, highlighting the importance of the choice of the observer coordinates for nonlinear systems. In particular, the first part covers state-affine forms with their Luenberger or Kalman designs, and triangular forms with their homogeneous high-gain designs. The second part addresses the transformation into linear forms through linearization by output injection or in the context of a nonlinear Luenberger design, and into triangular forms under the well-known uniform and differential observability assumptions. Finally, the third part presents some recently developed methods for avoiding the numerically challenging inversion of the transformation. Observer Design for Nonlinear Systems addresses students and researchers looking for an introduction to or an overview of the state of the art in observer design for nonlinear continuous-time dynamical systems. The book gathers the most important results focusing on a large and diffuse literature on general observer designs with global convergence, and is a valuable source of information for academics and practitioners.
Download or read book Historical Dictionary of Iran written by John Henry Lorentz and published by Historical Dictionaries of Asia, Oceania, and the Middle East. This book was released on 2007 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides an overview of specific events, movements, people, political and social groups, places, trends, and chronology. Allows for considerable exploration of a number of historical and contemporary topics and issues. The modern period, defined as 1800-present, is covered extensively.
Download or read book Control Systems with Actuator Saturation written by Tingshu Hu and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 397 pages. Available in PDF, EPUB and Kindle. Book excerpt: Saturation nonlinearities are ubiquitous in engineering systems. In control systems, every physical actuator or sensor is subject to saturation owing to its maximum and minimum limits. A digital filter is subject to saturation if it is implemented in a finite word length format. Saturation nonlinearities are also purposely introduced into engineering systems such as control sys tems and neural network systems. Regardless of how saturation arises, the analysis and design of a system that contains saturation nonlinearities is an important problem. Not only is this problem theoretically challenging, but it is also practically imperative. This book intends to study control systems with actuator saturation in a systematic way. It will also present some related results on systems with state saturation or sensor saturation. Roughly speaking, there are two strategies for dealing with actuator sat uration. The first strategy is to neglect the saturation in the first stage of the control design process, and then to add some problem-specific schemes to deal with the adverse effects caused by saturation. These schemes, known as anti-windup schemes, are typically introduced using ad hoc modifications and extensive simulations. The basic idea behind these schemes is to intro duce additional feedbacks in such a way that the actuator stays properly within its limits. Most of these schemes lead to improved performance but poorly understood stability properties.
