Download or read book Adaptive Algorithms for Active Noise Control in an Acoustic Duct written by Dariusz Bismor and published by . This book was released on 1999 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Application of Adaptive Techniques to Duct Active Noise Control written by Mark Johnson and published by . This book was released on 1992 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Evaluation of Current Adaptive Active Duct Noise Control Algorithms written by Michael David Lucey and published by . This book was released on 1996 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Adaptive Algorithms for Active Noise Control written by Angela Kuo Wang and published by . This book was released on 1996 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Adaptive and Optimal Control Strategies for Active Noise Cancellation in a One dimensional Acoustic Duct written by Ananth Krishnan and published by . This book was released on 2001 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Single and Multiple Channel Block Adaptive Algorithms for Active Noise Control written by Qun Shen and published by . This book was released on 1992 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Global Active Noise Control of a One dimensional Acoustic Duct Using a Feedback Controller written by Andrew James Hull and published by . This book was released on 1990 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Active Noise Control Technique Application in Air Conditioning Ducts written by Aloysius Decruz and published by . This book was released on 2009 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Active Noise Control (ANC) is a technique for reducing noise by destructive interference of noise sound wave by out-of-phase secondary sound wave. In air conditioning installations, high frequency noises are effectively attenuated by porous-structured medium; but the low frequency noise produced by the fan needs a more sophisticated approach. An algorithm, 'Hardware-Tuned Feedback ANC (HTFA)', has been developed to implement the ANC technique for the noise reduction application in an air conditioning duct element, where Digital Signal Processing is used to sample noise and produce a complete anti-phase noise produced by the HTFA algorithm. Typical blade pass frequency in the vicinity of 100 Hz require sampling frequency of minimum twice that value. A 600 MHz fixed point Digital Signal Processor (DSP) from Texas Instrument, TMS320C6416DSK, is used to generate a secondary sound field by using an adaptive algorithm of Least Mean Square (LMS) principle for convergence. A duct section is used for the experiment and the effectiveness of low frequency attenuation by the secondary sound field is measured. Low and medium frequency tonal noises of octave bands 63 Hz - 1000 Hz were tested, low frequency below 250 Hz being the range of interest. Optimum frequency values for which ANC is more effective are determined. It was found that Active Noise Cancellation is effective at 63 Hz and 125 Hz. This is a simple, economic and effective method for noise cancellation compared to existing feed-forward software tuned method.
Download or read book Optimal Spatially Fixed and Moving Virtual Sensing Algorithms for Local Active Noise Control written by Cornelis D. Petersen and published by . This book was released on 2007 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Local active noise control systems aim to create zones of quiet at specific locations within a sound field. The created zones of quiet generally tend to be small, especially for higher frequencies, and are usually centred at the error sensors. For an observer to experience significant reductions in the noise, the error sensors therefore have to be placed relatively close to an observer's ears, which is not always feasible or convenient. Virtual sensing methods have been proposed to overcome these problems that have limited the scope of successful local active noise control applications ... A number of virtual sensing algorithms have been proposed previously. The difference between these algorithms is the structure that is assumed to compute an estimate of the virtual error signals ... An optimal solution to the virtual sensing problem is therefore derived in this thesis using Kalman filtering theory. The proposed algorithm is implemented on an acoustic duct arrangement to demonstrate its effectiveness. The presented experimental results indicate that the zone of quiet was effectively moved away from the physical sensor towards the desired location of maximum attenuation. The previously proposed virtual sensing algorithms have been developed with the aim to create zones of quiet at virtual locations that are assumed spatially fixed within the sound field ... A moving virtual sensing method is therefore developed in this thesis that can be used to estimate the error signals at virtual locations that are moving through the sound field. It is shown that an optimal solution to the moving virtual sensing problem can be derived using Kalman filtering theory. A practical implementation of the developed algorithm is combined with an adaptive feedforward control algorithm and implemented on an acoustic duct arrangement. The presented experimental results illustrate that a narrowband moving zone of quiet that tracks the desired location of maximum attenuation has successfully been created." -- from Abstract.
Download or read book Active Noise Cancellation Using Selective Adaptive Filtering written by Oveal Walker and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intelligibility of speech and other audio in various acoustic environments can be very low based on the level of noise present in that space. Often in order to compensate for the noise in acoustic environments a passive approach is taken, in which sound absorption and isolation techniques are implemented throughout the physical space. Although this passive approach can provide suitable levels of noise reduction for a reasonable range of frequencies, several active noise control approaches are proven to be more effective, especially at frequencies below 500 Hz. Active Noise Control utilizes adaptive filtering algorithms to achieve significant noise attenuation of lower frequency noise that significantly degrades the desired audio signal. The level of effectiveness of various adaptive filtering algorithms can determine the overall noise attenuation and the rate at which the system attenuates the noise in the given space. Noise source location, level, and resonant space may dictate the amount of degradation caused on the input signal. Some acoustic spaces in which Active Noise Cancellation (ANC) headsets are used causes increasing resonance and inconsistent changes in noise power and amplitude. Special consideration of these signal characteristics are used to determine the stationary level of the noise signal, which is an ideal measure for determination of an adaptive filtering algorithm. Most Active Noise Control systems currently utilize only versions of the Least Mean Square adaptive filtering algorithm. This research will focus on a selective algorithm that will utilize descriptors to identify differences in the noise signal, and determine an optimal algorithm to be used for the filtering of distinct portions of the signal that are identified. The Recursive Least Squares adaptive algorithm will be used as the primary means of filtering due to its fast rate of convergence and tracking performance. A selective switching mechanism will be used to insure the Least Mean Squares algorithm is initiated only when signal conditions dictate effective noise control can be performed using this algorithm. Several different noise source environments are tested in order to attain the best active noise control solution to be used.
Download or read book The Active Noise Control of a One dimensional Duct written by Young-Su Lee and published by . This book was released on 1997 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Acoustic Prediction and Interior Noise Control Technology written by and published by DIANE Publishing. This book was released on 2001 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Robust Adaptive Algorithms for Active Noise Control written by Hui Lan and published by . This book was released on 2002 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Active Noise Control in Ducts Using Adaptive Digital Filters written by Laurent Ludovic Jerome Billet and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Algorithms for Active Noise Control and Their Applications written by Chaoying Bao and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development and Demonstration of Active Noise Control Concepts written by and published by . This book was released on 2000 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
