Study on the Frequency Domain Adaptive Algorithm for Active Control of Low Frequency Acoustic Noise
Project/Area Number  10650442 
Research Category 
GrantinAid for Scientific Research (C)

Allocation Type  Singleyear Grants 
Section  一般 
Research Field 
Control engineering

Research Institution  Tokyo National College of Technology 
Principal Investigator 
KOSAKA Toshifumi Tokyo National College of Technology Dept. Computer Science, Professor, 情報工学科, 教授 (60153524)

CoInvestigator(Kenkyūbuntansha) 
INOUE Yasuo INC Engineering co. ltd., Investing Engineer, 研究者職
MATSUBAYASHI Katsushi Tokyo National College of Technology Dept. Mechanical Engineering, lecturer, 機械工学科, 講師 (80239061)

Project Period (FY) 
1998 – 1999

Project Status 
Completed(Fiscal Year 1999)

Budget Amount *help 
¥2,300,000 (Direct Cost : ¥2,300,000)
Fiscal Year 1999 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1998 : ¥1,900,000 (Direct Cost : ¥1,900,000)

Keywords  active noise control / frequency domain adaptive algorithm / 周波数領域適応アルゴリズム 
Research Abstract 
In the area of the active acoustic noise control, if the frequency domain adaptive algorithm is employed, there will be possibility that it can obtain high conversion speed with modeling the plant parameters, because every frequency bin is controlled independently. Moreover, since the frequency domain algorithm makes use of Fast Fourier Transform it reduces the amount of calculation drastically. In addition, the calculation of the filtered X signal is also reduced. The main theme of this project is examining the behavior of the frequency domain adaptive algorithm in both the simulation and real experimental apparatus. First, the semi rectangular window function was investigated. It is used in estimation of the cross spectrum that is necessary in the frequency domain adaptive algorithm. The window function of semi rectangular is used for the reference signal of the active control system, while the normal rectangular window function is for the error signal of the active control system. It
… More
is proved that the usage of the semi rectangular window function for the reference signal provides proper estimation of impulse response without any bias. The block length for FFT should be more than twice of the tap length of control filter, but just twice is recommended. The block length for FFT that is twice of the tap length of control filter is used widely in overlapped method. Second, the new the frequency domain adaptive algorithm was suggest. It updates the control filter specific characteristic without the prior modeling work. The algorithm uses every control trial result with weight, while the algorithm I suggested before uses recent two trial results. The new algorithm always estimates the parameter of the active system with all of control history, and it can follow the change of the transfer functions of both the primary acoustic path and the plant i.e. secondary path. Until now, the numeric simulation of the active control of the duct noise was completed. The numeric simulation of the active control of the duct noise with acoustic feedback path was completed. The active control of the real duct noise with acoustic feedback path was completed. Less

Report
(3results)
Research Output
(4results)