Download or read book Interior Noise Reduction by Adaptive Feedback Vibration Control written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-18 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this project is to investigate the possible use of adaptive digital filtering techniques in simultaneous, multiple-mode identification of the modal parameters of a vibrating structure in real-time. It is intended that the results obtained from this project will be used for state estimation needed in adaptive structural acoustics control. The work done in this project is basically an extension of the work on real-time single mode identification, which was performed successfully using a digital signal processor (DSP) at NASA, Langley. Initially, in this investigation the single mode identification work was duplicated on a different processor, namely the Texas Instruments TMS32OC40 DSP. The system identification results for the single mode case were very good. Then an algorithm for simultaneous two mode identification was developed and tested using analytical simulation. When it successfully performed the expected tasks, it was implemented in real-time on the DSP system to identify the first two modes of vibration of a cantilever aluminum beam. The results of the simultaneous two mode case were good but some problems were identified related to frequency warping and spurious mode identification. The frequency warping problem was found to be due to the bilinear transformation used in the algorithm to convert the system transfer function from the continuous-time domain to the discrete-time domain. An alternative approach was developed to rectify the problem. The spurious mode identification problem was found to be associated with high sampling rates. Noise in the signal is suspected to be the cause of this problem but further investigation will be needed to clarify the cause. For simultaneous identification of more than two modes, it was found that theoretically an adaptive digital filter can be designed to identify the required number of modes, but the algebra became very complex which made it impossible to implement in the DSP system used in this study....

Download or read book Understanding Active Noise Cancellation written by Colin N. Hansen and published by CRC Press. This book was released on 2002-05-03 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding Active Noise Cancellation Provides a concise introduction to the fundamentals and applications of active control of vibration and sound for the non-expert. It is also a useful quick reference for the specialist engineer. The book emphasises the practical applications of technology, and complex control algorithms and structures are only discussed to the extent that they aid understanding. Extensive recommendations for further reading on the subject are provided, but the text will stand alone for those seeking an overview of the key issues: fundamentals, control systems, transducers, applications and possible future directions.

Download or read book Active Sound and Vibration Control written by M. O. Tokhi and published by IET. This book was released on 2002 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the established fundamentals in the area of active sound and vibration control and explores new and emerging technologies and techniques. The latest theoretical, algorithmic and practical applications are covered.

Download or read book Active Control of Noise and Vibration written by Colin Hansen and published by CRC Press. This book was released on 2012-11-02 with total page 1564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integrating active control of both sound and vibration, this comprehensive two-volume set combines coverage of fundamental principles with the most recent theoretical and practical developments. The authors explain how to design and implement successful active control systems in practice and detail the pitfalls one must avoid to ensure a reliable and stable system. Extensively revised, updated, and expanded throughout, the second edition reflects the advances that have been made in algorithms, DSP hardware, and applications since the publication of the first edition.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Adaptive Feed Forward Control of Low Frequency Interior Noise written by Thomas Kletschkowski and published by Springer Science & Business Media. This book was released on 2011-10-29 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a mechatronic approach to Active Noise Control (ANC). It describes the required elements of system theory, engineering acoustics, electroacoustics and adaptive signal processing in a comprehensive, consistent and systematic manner using a unified notation. Furthermore, it includes a design methodology for ANC-systems, explains its application and describes tools to be used for ANC-system design. From the research point of view, the book presents new approaches to sound source localization in weakly damped interiors. One is based on the inverse finite element method, the other is based on a sound intensity probe with an active free field. Furthermore, a prototype of an ANC-system able to reach the physical limits of local (feed-forward) ANC is described. This is one example for applied research in ANC-system design. Other examples are given for (i) local ANC in a semi-enclosed subspace of an aircraft cargo hold and (ii) for the combination of audio entertainment with ANC.

Download or read book Signal Processing for Active Control written by Stephen Elliott and published by Elsevier. This book was released on 2000-09-26 with total page 531 pages. Available in PDF, EPUB and Kindle. Book excerpt: Signal Processing for Active Control sets out the signal processing and automatic control techniques that are used in the analysis and implementation of active systems for the control of sound and vibration. After reviewing the performance limitations introduced by physical aspects of active control, Stephen Elliott presents the calculation of the optimal performance and the implementation of adaptive real time controllers for a wide variety of active control systems.Active sound and vibration control are technologically important problems with many applications. 'Active control' means controlling disturbance by superimposing a second disturbance on the original source of disturbance. Put simply, initial noise + other specially-generated noise or vibration = silence [or controlled noise]. This book presents a unified approach to techniques that are used in the analysis and implementation of different control systems. It includes practical examples at the end of each chapter to illustrate the use of various approaches.This book is intended for researchers, engineers, and students in the field of acoustics, active control, signal processing, and electrical engineering.

Download or read book Variational Analysis and Aerospace Engineering written by Giuseppe Buttazzo and published by Springer Science & Business Media. This book was released on 2009-08-21 with total page 527 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Variational Analysis and Aerospace Engineering conference held in Erice, Italy in September 2007 at International School of Mathematics, Guido Stampacchia provided a platform for aerospace engineers and mathematicians to discuss the problems requiring an extensive application of mathematics. This work contains papers presented at the workshop.

Download or read book Active Control of Vibration written by Christopher C. Fuller and published by Academic Press. This book was released on 1996-02-08 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a companion text to Active Control of Sound by P.A. Nelson and S.J. Elliott, also published by Academic Press. It summarizes the principles underlying active vibration control and its practical applications by combining material from vibrations, mechanics, signal processing, acoustics, and control theory. The emphasis of the book is on the active control of waves in structures, the active isolation of vibrations, the use of distributed strain actuators and sensors, and the active control of structurally radiated sound. The feedforward control of deterministic disturbances, the active control of structural waves and the active isolation of vibrations are covered in detail, as well as the more conventional work on modal feedback. The principles of the transducers used as actuateors and sensors for such control strategies are also given an in-depth description. The reader will find particularly interesting the two chapters on the active control of sound radiation from structures: active structural acoustic control. The reason for controlling high frequency vibration is often to prevent sound radiation, and the principles and practical application of such techniques are presented here for both plates and cylinders. The volume is written in textbook style and is aimed at students, practicing engineers, and researchers. Combines material from vibrations, signal processing, mechanics, and controls Summarizes new research in the field

Download or read book Comprehensive Investigation on Active Passive Hybrid Isolation and Tunable Dynamic Vibration Absorption written by Fei Wang and published by Springer. This book was released on 2018-12-17 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses efforts to control the low-frequency vibration transmission of typical power equipment and pipeline systems of ships, exploring the use of active and passive hybrid vibration isolation and adjustable dynamic vibration absorption technologies. It also proposes an adaptive feed-forward control strategy and studies a distributed feed-forward control hardware system. In addition, the book presents a three-way dynamic vibration absorption theory used to design a pipeline-system adjustable dynamic vibration absorber, which offers a number of advantages, such as compact structure, easy assembly and disassembly, low power consumption, excellent vibration control effect and wide frequency band adjustable ability, etc. This book is a valuable resource for researchers and engineers in the fields of noise and vibration control, active control systems, active vibration isolation and adaptive dynamic vibration absorption.

Download or read book Adaptive tolerant and efficient composite structures written by Martin Wiedemann and published by Springer Science & Business Media. This book was released on 2012-08-01 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Composite structures are most efficient in performance and production cost when combined with smart materials making them adaptable to changing operational conditions. The specific production processes of composites offer the possibility to integrate more functions thus making the structure more valuable. Active functions can be realized by smart materials, e.g. morphing, active vibration control, active structure acoustic control or structure health monitoring. The foundation is a sound understanding of materials, design methods, design principles, production technologies and adaptronics. Along the complete process chain this disciplines together deliver advanced lightweight solutions for applications ranging from mechanical engineering to vehicles, airframe and finally space structures. This book provides the scientific foundations as well as inspiring new ideas for engineers working in the field of composite lightweight structures.

Download or read book Topics in Modal Analysis Volume 7 written by Randall Allemang and published by Springer Science & Business Media. This book was released on 2013-07-03 with total page 779 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topics in Modal Analysis, Volume 7: Proceedings of the 31st IMAC, A Conference and Exposition on Structural Dynamics, 2013, the seventh volume of seven from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Structural Dynamics, including papers on: Fluid Structure Interaction Adaptive Structures Experimental Techniques Analytical Methods Damage Detection Damping of Materials & Members Modal Parameter Identification Modal Testing Methods System Identification Active Control Modal Parameter Estimation Processing Modal Data

Download or read book Adaptive and Robust Active Vibration Control written by Ioan Doré Landau and published by Springer. This book was released on 2016-09-15 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book approaches the design of active vibration control systems from the perspective of today’s ideas of computer control. It formulates the various design problems encountered in the active management of vibration as control problems and searches for the most appropriate tools to solve them. The experimental validation of the solutions proposed on relevant tests benches is also addressed. To promote the widespread acceptance of these techniques, the presentation eliminates unnecessary theoretical developments (which can be found elsewhere) and focuses on algorithms and their use. The solutions proposed cannot be fully understood and creatively exploited without a clear understanding of the basic concepts and methods, so these are considered in depth. The focus is on enhancing motivations, algorithm presentation and experimental evaluation. MATLAB®routines, Simulink® diagrams and bench-test data are available for download and encourage easy assimilation of the experimental and exemplary material. Three major problems are addressed in the book: active damping to improve the performance of passive absorbers; adaptive feedback attenuation of single and multiple tonal vibrations; and feedforward and feedback attenuation of broad band vibrations. Adaptive and Robust Active Vibration Control will interest practising engineers and help them to acquire new concepts and techniques with good practical validation. It can be used as the basis for a course for graduate students in mechanical, mechatronics, industrial electronics, aerospace and naval engineering. Readers working in active noise control will also discover techniques with a high degree of cross-over potential for use in their field.

Download or read book Control of Noise and Structural Vibration written by Qibo Mao and published by Springer Science & Business Media. This book was released on 2013-06-02 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Control of Noise and Structural Vibration presents a MATLAB®-based approach to solving the problems of undesirable noise generation and transmission by structures and of undesirable vibration within structures in response to environmental or operational forces. The fundamentals of acoustics, vibration and coupling between vibrating structures and the sound fields they generate are introduced including a discussion of the finite element method for vibration analysis. Following this, the treatment of sound and vibration control begins, illustrated by example systems such as beams, plates and double walls. Sensor and actuator placement is explained as is the idea of modal sensor–actuators. The design of appropriate feedback systems includes consideration of basic stability criteria and robust active structural acoustic control. Positive position feedback (PPF) and multimode control are also described in the context of loudspeaker–duct and loudspeaker–microphone models. The design of various components is detailed including the analog circuit for PPF, adaptive (semi-active) Helmholtz resonators and shunt piezoelectric circuits for noise and vibration suppression. The text makes extensive use of MATLAB® examples and these can be simulated using files available for download from the book’s webpage at springer.com. End-of-chapter exercises will help readers to assimilate the material as they progress through the book. Control of Noise and Structural Vibration will be of considerable interest to the student of vibration and noise control and also to academic researchers working in the field. It’s tutorial features will help practitioners who wish to update their knowledge with self-study.

Download or read book Noise news International written by and published by . This book was released on 1995 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dynamic Modeling and Active Vibration Control of Structures written by Moon Kyu Kwak and published by Springer Nature. This book was released on 2021-08-14 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the active vibration control techniques which have been developed to suppress excessive vibrations of structures. It covers the fundamental principles of active control methods and their applications and shows how active vibration control techniques have replaced traditional passive vibration control. The book includes coverage of dynamic modeling, control design, sensing methodology, actuator mechanism and electronic circuit design, and the implementation of control algorithms via digital controllers. An in-depth approach has been taken to describe the modeling of structures for control design, the development of control algorithms suitable for structural control, and the implementation of control algorithms by means of Simulink block diagrams or C language. Details of currently available actuators and sensors and electronic circuits for signal conditioning and filtering have been provided based on the most recent advances in the field. The book is used as a textbook for students and a reference for researchers who are interested in studying cutting-edge technology. It will be a valuable resource for academic and industrial researchers and professionals involved in the design and manufacture of active vibration controllers for structures in a wide variety of fields and industries including the automotive, rail, aerospace, and civil engineering sectors.

Download or read book Adaptive Structures Tenth International Conference Proceedings written by Roger Ohayon and published by CRC Press. This book was released on 2000-03-13 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: