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이경태(Gyeong-Tae Lee),오재응(Jae-Eung Oh),이해진(Hae-Jin Lee),방승우(Seung-Woo Bang),이정윤(Jung-Youn Lee) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11
The method of the reduction of the duct noise can be classified by the method of passive control and the method of active control. However, the passive control method has a demerit to reduce the effect of noise reduction at low frequency (below 500Hz) range and to be limited by a space. Whereas, the active control method can overcome the demerit of passive control method. The algorithm of active control is mostly used the Least-Mean-Square (LMS) algorithm because the LMS algorithm can easily obtain the complex transfer function in real-time. Especially, When the Filtered-X LMS (FXLMS) algorithm is applied to an ANC system. However, the convergence performance of LMS algorithm goes bad when the FXLMS algorithm is applied to an active control of duct noise under rapidly accelerated conditions. Thus Correlation FXLMS (Co-FXLMS) algorithm was developed to improve the control performance under the rapid acceleration. The Co-FXLMS algorithm is realized by using an estimate of the cross correlation between the adaptation error and the filtered input signal to control the step size. In this paper, the performance of the Co-FXLMS is presented in comparison with that of the FXLMS algorithm. Experimental results show that active noise control using Co-FXLMS is effective to reduce duct noise under the rapidly accelerated conditions.
적응 신호처리 방법을 이용한 덕트계의 능동 소음제어에 관한 연구
김동규,이태연 조선대학교 생산기술연구소 1991 生産技術硏究 Vol.13 No.1
The problem of active noise control has been analyzed using a adaptive signal processing technique. The problem of acoustic feedback has been considered in detail. In the solutions presented here the acoustic feedback path and acoustic propagation delay are conidered a part of the model which led the use of the pole-zero or IIR adaptive filter. Using the concept of observability, the RLMS algorithm has been shown to be particularily useful for active noise control system. The effect of error path and auxilary path transfer function has been ianalyzed and a new on-line techique for error path modeling, adaptive delayed inverse modeling has been preseted. Using these new concepts, large amounts of attenuation has been achieved in computer simulation. In addition to offering an alternative to traditional passive silencing techniques, active noise cotrol scheme may offer solutions to noise problems for which there were previously no practical passive approaaches.