Active Noise Control Primer

ISBN-13: 9780387989518 / Angielski / Twarda / 2000 / 159 str.

Scott D. Snyder; S. D. Snyder

Opis

Active noise control - the reduction of noise by generating an acoustic signal that actively interferes with the noise - has become an active area of basic research and engineering applications. The aim of this book is to present all of the basic knowledge one needs for assessing how useful active noise control will be for a given problem and then to provide some guidance for designing, setting up, and tuning an active noise-control system. Written for students who have no prior knowledge of acoustics, signal processing, or noise control but who do have a reasonable grasp of basic physics and mathematics, the book is short and descriptive. It leaves for more advanced texts or research monographs all mathematical details and proofs concerning vibrations, signal processing and the like. The book can thus be used in independent study, in a classroom with laboratories, or in conjunction with a kit for experiment or demonstration. Topics covered include: basic acoustics; human perception and sound; sound intensity and related concepts; fundamentals of passive noise-control strategies; basics of digital systems; basics of adaptive controllers; and active noise control systems.

Recenzje

From the reviews:

Graduate students and professionals who are new to the field of active control are often faced with the fact that they need a working knowledge of several fields, such as microelectronics and digital signal processing, in addition to being well versed in acoustics and noise control. This book certainly fills the need of such readers and assumes no background in any of the fields mentioned above...Furthermore the author has narrated these with considerable wit, making the reading rather pleasurable. Overall, I would recommend this book readily for any serious student embarking on research in the area of active control.

--Measurement Science and Technology

"The author gives an overview of acoustics, noise control, and application areas where active noise control is applicable. ... It is also worth mentioning that this book definitely has a sense of humor ... . The author has done a very good job of providing simple explanations for many of the features ... . This text has the virtue of living up to its title of being a primer. ... the author provides some very good descriptions that should lead to understanding for the uninitiated." (Scott D. Sommerfeldt, Noise Control Engineering Journal, Vol. 53 (5), 2005)

"Acoustic noise is a real problem in many environments ... . the book is designed for engineering students who want to acquire some background in this field without going into mathematical detail, hence the word 'Primer' in the title. ... The approach is practical and the level ideal for physics or engineering students, at advanced undergraduate or beginning graduate level ... . It is also the sort of book that lecturers and practitioners in related fields could read with profit. I recommend it strongly." (Neville Fletcher, The Physicist, Vol. 38 (3), 2001)

Spis treści

1. Introduction.- Welcome to the World of Active Noise Control!.- Summary.- Do I Have to Read the Whole Book?.- What Is Active Noise Control?.- Adaptive Feedforward Active Control Noise.- Advanced Reading.- 2. Background: Fundamentals of Sound.- What Is Sound?.- What Is Noise?.- Quantifying Sound Levels.- Sound Waves.- Frequency Analysis.- Sine Waves.- Fourier Analysis.- Harmonics.- 1. Anything that Rotates.- 2. Many Devices Which Use Mains Electricity.- 3. Devices Which Are Driven Beyond Their Capabilities.- Human Perception of Sound.- Acceptable Sound Levels.- 3. Fundamentals of Noise Control.- Prerequisite Discussion: Power and Impedance.- The Magnitude of Acoustic Power.- Decibel Units for Acoustic Power.- Power, Pressure, and Hearing Loss.- Real and Imaginary Impedancec.- What Is Noise Control?.- What Is Passive Noise Control.- What is Active Noise Control?.- 4. Free Space Noise Control.- Passive Noise Control Approaches.- Control Control Approaches.- 5. Enclosed Space Noise Control.- Where Does the Sound Come From?.- How Does the Sound Get Out Again?.- How Does the Sound Field Arrange Itself?.- Passive Noise Control Approaches.- Active Noise Control Approaches.- 6. Control of Sound Propagation in Ducts.- Sound Fields in Ducts.- Modes in Ducts.- Impedance in Ducts.- Passive Noise Control Approaches.- Sidebranch Resonator.- Expansion Chamber.- Helmholtz Filter.- Dissipative Passive Control Techniques.- Active Noise Control Approaches.- Reference and Error Signal Quality.- Reference Sensor/Control Source Separation Distance.- Control Source Position in the Duct.- Duct Response Characteristics.- 7. Active Noise Controller Overview.- Some Important Facts.- Digital System Requirements.- Controller Output (Digital Control Filter) Requirements.- Adaptive Algorithm Requirements.- 8. Controller Fundamentals.- General Control System Outlines and Definitions.- Physical System Limitations.- Interfacing a Digital System.- Background.- Required Additions for Digital Control.- Overview of the Controller.- Controller Component 1: The Digital Filter.- What Is a Digital Filter?.- Specifying the “Appropriate” Digital Filter.- Specifying the Digital Filter Length.- Controller Component 2: The Adaptive Algorithm.- Background: Making Use of Adaptive Signal Processing.- Gradient Descent Algorithms.- Evaluating the Gradient.- The Convergence Coefficient.- Quantization Errors and Leakage.- Slowing Down the Algorithm to Improve Performance.- Controller Component 3: Cancellation Path Modeler.- Selecting the Sample Rate.- So What Is the Optimum Sample Rate?.