Concepts of Active Noise Aircraft Cockpits Reduction Employed in High Noise Level
During the past two decades, reducing exposure to high-level noise in aircraft cockpits by methods of active noise control (ANC) has aroused the interest of researchers. Also, some commercial applications were initiated by leading manufacturers. For this purpose, fundamentally different approaches were used. While active noise compensation reduces the noise level by generating an interfering antinoise, structural vibration control aims to limit sound emittance through active damping of the aircraft structure vibrations. These approaches are linked with very different financial and technical boundary conditions, which implied distinct degrees of success. The ANC approaches used in cockpit noise reduction will be summarised, and their success or failure reasons will be analysed. Thereafter, the focus will be set on the industrially more successful way of protecting pilots from high noise levels, which is the use of active headsets. The development and the current state of commercial products will be presented, and the requirements of future trends will be derived. These requirements consist in extending the band width of noise reduction and making the control adaptive to changing conditions. Finally, the development of a prototype of a new generation of ANC headsets is presented. The prototype combines standard feedback with adaptive feedforward control techniques and processes the control algorithms by an integrated DSP platform.
KeywordsNoise Reduction Active Noise Noise Cancellation Interior Noise Active Noise Control
Unable to display preview. Download preview PDF.
- 1.Kuo, S.M., Morgan, D.R.: Active Noise Control Systems, Algorithms and DSP Implementations. Wiley-Interscience Publication, New York (1996)Google Scholar
- 3.Enghardt, L., Tapken, U., Neise, W., Schimming, P.: Experimentelle Untersuchungen zur aktiven Schallminderung. Abschlussbericht, Turbotech II, Teilprojekt 1.231 Foerderkennzeichen 0327040D (2000)Google Scholar
- 5.Foudhaili, H., Wolter, B., Reithmeier, E., Peissig, J.: Feedback-Feedforward aktive Laermkompensation fuer den Kopfhoerer. Fortschritte der Akustik, 33. Jahrestagung fuer Akustik DAGA, Stuttgart, 705–6, (2007)Google Scholar
- 6.Golub, R.A., Rawls, J.W., Russell, J.W.: Evaluation of the Advanced Subsonic TechnologyProgram Noise Reduction Benefits. NASA Center for AeroSpace Information, (2005)Google Scholar
- 7.Gorman, J., Hinchliffe, R., Stothers, I.: Active Sound Control on the Flight Deck of a C130 Hercules. Proceedings of the 2004 International Symposium on Active Control of Sound and Vibration, CD-ROM (2004)Google Scholar
- 8.Hansen, C.H.: Active Noise Control - from Laboratory to Industrial Implementation. Proceedings of NOISE-CON97, 1, 3-38 (1997)Google Scholar
- 9.Hansen, C.H.: Current and Future Industrial Applications of Active Noise Control. Proceedings of the 2004 International Symposium on Active Control of Sound and Vibration, CD-ROM (2004)Google Scholar
- 10.Hinchliffe, R.A., Scott, I.A., Purver, M.J., Stothers, I.M.: Tonal Active Control in Production on a Large Turbo-prop Aircraft. Proceedings of ACTIVE 02, The International Symposium on Active Control of Sound and Vibration, CD-ROM (2002)Google Scholar
- 11.Maier, R., Pucher, M., Gembler, W., Schweitzer, H.: Helicopter Interior Noise Reduction by Active Vibration Isolation with Smart Gearbox Struts. Proceedings of ACTIVE 99, the International Symposium on Active Control of Sound and Vibration, CD-ROM (1999)Google Scholar
- 13.Petitjean, B., Greffe, C.: Active Interior Noise Control: An Industrial Perspective. Proceedings of the SPIE — The International Society for Optical Engineering, 4698, 133–42 (2002)Google Scholar
- 15.Wolter, B., Foudhaili, H., Peissig, J., Reithmeier, E.: Combined Feedback and Adaptive Feedforward Active Noise Control in Headsets. Proc. of Internoise, the 36th Int. Congress and Exhibition on Noise Control Engineering, Istanbul, CD-ROM (2007)Google Scholar