Download or read book Comparison of Interpolation Methods as Applied to Time Synchronous Averaging written by and published by . This book was released on 1999 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several interpolation techniques were investigated to determine their effect on time synchronous averaging of gear vibration signals and also the effects on standard health monitoring diagnostic parameters. The data was also digitally resampled to determine the effect of lower acquisition rates. The analysis used previously recorded vibration data taken during Health and Usage Monitoring gear testing at the NASA Glenn Research Center. The gear testing monitored the development of surface pitting fatigue on aerospace quality spur gears. Linear, cubic and spline interpolation methods were investigated. Comparisons between the resultant averages show that while there are differences in the resultant time synchronous averages, the differences are not obvious. The diagnostic parameters tested were FM4 and NA4. There are significant differences in the percent deviation curves which imply that the magnitudes of the errors increase as the sample rate decreases.
Download or read book Prognostics and Health Management of Electronics written by Michael G. Pecht and published by John Wiley & Sons. This book was released on 2008-09-11 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book on Prognostics and Health Management of Electronics Recently, the field of prognostics for electronic products has received increased attention due to the potential to provide early warning of system failures, forecast maintenance as needed, and reduce life cycle costs. In response to the subject's growing interest among industry, government, and academic professionals, this book provides a road map to the current challenges and opportunities for research and development in Prognostics and Health Management (PHM). The book begins with a review of PHM and the techniques being developed to enable a prognostics approach for electronic products and systems. building on this foundation, the book then presents the state of the art in sensor systems for in-situ health and usage monitoring. Next, it discusses the various models and algorithms that can be utilized in PHM. Finally, it concludes with a discussion of the opportunities in future research. Readers can use the information in this book to: Detect and isolate faults Reduce the occurrence of No Fault Found (NFF) Provide advanced warning of system failures Enable condition-based (predictive) maintenance Obtain knowledge of load history for future design, qualification, and root cause analysis Increase system availability through an extension of maintenance cycles and/or timely repair actions Subtract life cycle costs of equipment from reduction in inspection costs, down time, and inventory Prognostics and Health Management of Electronics is an indispensable reference for electrical engineers in manufacturing, systems maintenance, and management, as well as design engineers in all areas of electronics.
Download or read book Diagnostics and Prognostics of Aerospace Engines written by Ravi Rajamani and published by SAE International. This book was released on 2018-11-28 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: The propulsion system is arguably the most critical part of the aircraft; it certainly is the single most expensive component of the vehicle. Ensuring that engines operate reliably without major maintenance issues is an important goal for all operators, military or commercial. Engine health management (EHM) is a critical piece of this puzzle and has been a part of the engine maintenance for more than five decades. In fact, systematic condition monitoring was introduced for engines before it was applied to other systems on the aircraft. Diagnostics and Prognostics of Aerospace Engines is a collection of technical papers from the archives of SAE International, which introduces the reader to a brief history of EHM, presents some examples of EHM functions, and outlines important future trends. The goal of engine health maintenance is ultimately to reduce the cost of operations by catching problems before they become major issues, by helping reduce repair times through diagnostics, and by facilitating logistic optimization through prognostic estimates. Diagnostics and Prognostics of Aerospace Engines shows that the essence of these goals has not changed over time.
Download or read book Gear Crack Detection Using Tooth Analysis written by and published by . This book was released on 2002 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gear cracks are typically difficult to diagnose with sufficient warning time. Significant damage must he present before algorithms detect the damage. A new feature extraction and two new detection techniques are proposed. The time synchronous averaging concept was extended from revolution-based to tooth engagement-based. The detection techniques are based on statistical comparisons among the averages for the individual teeth. These techniques were applied to a series of three seeded fault crack propagation tests. These tests were conducted on aerospace quality spur gears in a test rig. The tests were conducted at speeds ranging from 2500 to 7500 revolutions per minute and torque from 184 to 228 percent of design load. The inability to detect these cracks with high confidence may be caused by the high loading required to initiate the cracks. The results indicate that these techniques do not currently produce an indication of damage that significantly exceeds experimental scatter.
Download or read book Non Destructive Testing and Condition Monitoring Techniques for Renewable Energy Industrial Assets written by Mayorkinos Papaelias and published by Butterworth-Heinemann. This book was released on 2019-09-04 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-Destructive Testing and Condition Monitoring Techniques for Renewable Energy Industrial Assets integrates state-of-the-art information and discusses future developments and their significance to the improvement of the renewable energy industry. Renewable energy assets are complex systems with several critical components that require inspection and adequate maintenance in order to ensure their high availability and uninterrupted operation. This is the first book to apply NDT and condition monitoring to these complex systems. Covers inspection and condition monitoring for a broad range of renewable energy systems, including wind turbines, wave energy devices, CSP and photovoltaic plants, and biofuel/biomass power plants Includes a review of common types of NDT techniques Discusses future developments in NDT and condition monitoring for renewable energy systems
Download or read book Integrated Vehicle Health Management written by Ian K Jennions and published by SAE International. This book was released on 2013-09-25 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integrated Vehicle Health Management (IVHM) is a relatively new subject, with its roots back in the space sector of the early 1990s. Although many of the papers written around that time did not refer to it as IVHM, the fundamental principles of considering an integrated end-to-end system to monitor the overall health of the asset were clearly visible. As the subject of Integrated Vehicle Health Management (IVHM) and its associated technologies have grown up, businesses are making the transformation from selling a product to selling a service. This can be viewed as a positive disruption, as a relatively small technology breakthrough is being brought to market for a large business benefit. The sequence “sense—acquire—transfer—analyze—act “ feeds the information (processed data) on the asset’s health into the Operations or Management control center. Here, decisions can be made on maintenance actions with knowledge of the supply chain status, MRO loading, etc., provided by Maintenance and Logistics systems. Undoubtedly, a much more efficient and economical modus operandi. This book brings together a collection of twenty –two SAE International Technical papers on this very theme, organized according to specific areas of interest: • Engines • Airframes • Electrical Power Systems • Supporting Systems • Architecture They were selected by Dr. Ian K. Jennions, Director of IVHM Center at Cranfield University, in the UK. Dr. Jennions was also the editor of three other books on Integrated Vehicle Health Management, published by SAE International: • IVHM: Perspectives on an Emerging Field • IVHM: Business Case Theory and Practice • IVHM: The Technology
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 2000 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spiral Bevel Pinion Crack Detection in a Helicopter Gearbox written by and published by . This book was released on 2003 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The vibration resulting from a cracked spiral bevel pinion was recorded and analyzed using existing Health and Usage Monitoring System (HUMS) techniques. A tooth on the input pinion to a Bell OH-58 main rotor gearbox was notched and run for an extended period at severe over-torque condition to facilitate a tooth fracture. Thirteen vibration-based diagnostic metrics were calculated throughout the run. After 101.41 hours of run time, some of the metrics indicated damage. At that point a visual inspection did not reveal any damage. The pinion was then run for another 12 minutes until a proximity probe indicated that a tooth had fractured. This paper discusses the damage detection effectiveness of the different metrics and a comparison of effects of the different accelerometer locations.
Download or read book Rotating Machinery Structural Health Monitoring Shock and Vibration Volume 5 written by Tom Proulx and published by Springer Science & Business Media. This book was released on 2011-03-24 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rotating Machinery, Structural Health Monitoring, Shock and Vibration, Volume 5 Proceedings of the 29th IMAC, A Conference and Exposition on Structural Dynamics, 2011, the fifth volume of six from the Conference, brings together 35 contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Rotating Machinery, Structural Health Monitoring, as well as Shock and Vibration, along with other structural engineering areas.
Download or read book Soviet bloc Research in Geophysics Astronomy and Space written by and published by . This book was released on 1967 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Wavelet Theory and Their Applications in Engineering Physics and Technology written by Dumitru Baleanu and published by BoD – Books on Demand. This book was released on 2012-04-04 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of the wavelet transform to analyze the behaviour of the complex systems from various fields started to be widely recognized and applied successfully during the last few decades. In this book some advances in wavelet theory and their applications in engineering, physics and technology are presented. The applications were carefully selected and grouped in five main sections - Signal Processing, Electrical Systems, Fault Diagnosis and Monitoring, Image Processing and Applications in Engineering. One of the key features of this book is that the wavelet concepts have been described from a point of view that is familiar to researchers from various branches of science and engineering. The content of the book is accessible to a large number of readers.
Download or read book Biomag 96 written by Cheryl J. Aine and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 1218 pages. Available in PDF, EPUB and Kindle. Book excerpt: A modified Linear Estimation Approach was performed to reconstruct current sources within the heart. Based on MRI data sets the Boundary Element Method was used to create tailored multicompartment models of the human thorax which were used to solve the forward problem of magnetocardiography. The ability of the proposed method was demonstrated for the localization of a single current dipole as an example of a focal source. By means of introducing small shiftings to all reconstruction dipoles during linear estimation solution as well as performing a successive focussing strategy ignoring places without significant electrical activity the method could easily be extended to the reconstruction of real 3D sources. Based on a special minimum-norm solution the source volume can be estimated applying a finite element approximation using cube elements. The size of an extended current source can be estimated by superimposing the reconstructed dipoles to an equivalent dipole and comparing the corresponding volume with the sphere which would be related to the equivalent dipole. The deviation of these volumes can be taken as a criterion for non-dipolarity of sources.
Download or read book Computational Biomechanics for Medicine written by Adam Wittek and published by Springer. This book was released on 2017-04-29 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume comprises the latest developments in both fundamental science and patient-specific applications, discussing topics such as: cellular mechanics; injury biomechanics; biomechanics of heart and vascular system; medical image analysis; and both patient-specific fluid dynamics and solid mechanics simulations. With contributions from researchers world-wide, the Computational Biomechanics for Medicine series of titles provides an opportunity for specialists in computational biomechanics to present their latest methodologies and advancements.
Download or read book Monthly Weather Review written by and published by . This book was released on 1992 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modularity in Motor Control From Muscle Synergies to Cognitive Action Representation written by Andrea d'Avella and published by Frontiers Media SA. This book was released on 2016-04-21 with total page 794 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mastering a rich repertoire of motor behaviors, as humans and other animals do, is a surprising and still poorly understood outcome of evolution, development, and learning. Many degrees-of-freedom, non-linear dynamics, and sensory delays provide formidable challenges for controlling even simple actions. Modularity as a functional element, both structural and computational, of a control architecture might be the key organizational principle that the central nervous system employs for achieving versatility and adaptability in motor control. Recent investigations of muscle synergies, motor primitives, compositionality, basic action concepts, and related work in machine learning have contributed to advance, at different levels, our understanding of the modular architecture underlying rich motor behaviors. However, the existence and nature of the modules in the control architecture is far from settled. For instance, regularity and low-dimensionality in the motor output are often taken as an indication of modularity but could they simply be a byproduct of optimization and task constraints? Moreover, what are the relationships between modules at different levels, such as muscle synergies, kinematic invariants, and basic action concepts? One important reason for the new interest in understanding modularity in motor control from different viewpoints is the impressive development in cognitive robotics. In comparison to animals and humans, the motor skills of today’s best robots are limited and inflexible. However, robot technology is maturing to the point at which it can start approximating a reasonable spectrum of isolated perceptual, cognitive, and motor capabilities. These advances allow researchers to explore how these motor, sensory and cognitive functions might be integrated into meaningful architectures and to test their functional limits. Such systems provide a new test bed to explore different concepts of modularity and to address the interaction between motor and cognitive processes experimentally. Thus, the goal of this Research Topic is to review, compare, and debate theoretical and experimental investigations of the modular organization of the motor control system at different levels. By bringing together researchers seeking to understand the building blocks for coordinating many muscles, for planning endpoint and joint trajectories, and for representing motor and behavioral actions in memory we aim at promoting new interactions between often disconnected research areas and approaches and at providing a broad perspective on the idea of modularity in motor control. We welcome original research, methodological, theoretical, review, and perspective contributions from behavioral, system, and computational motor neuroscience research, cognitive psychology, and cognitive robotics.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1996 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
