An Online Secondary Path Modeling Method for Active Nosie Control System

• Main Authors: Guan-Hong Chen, 陳冠宏
• Other Authors: 林忠逸
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/15139413729950997777

碩士 === 國立中興大學 === 機械工程學系所 === 99 === In active noise control (ANC) systems, the FxLMS algorithm is widely used due to its simplicity. However, a secondary- path transfer function is required in the FxLMS algorithm. The secondary- path transfer function is generally obtained from an off-line identification method. If the secondary path is time varying, the identified transfer function may lose its accuracy and an online secondary-path modeling technique can thus be needed. This study proposes a new online secondary-path modeling method for ANC where a compensator is utilized to provide signals for compensation in the secondary-path identification and in ANC. In order to enhance speed of convergence rate and level of noise reduction in ANC system, this study also uses exponential-decay step size. Computer simulation shows that the proposed method has better ANC performance as compared to that of existing methods. Experimental results validate the effectiveness of the proposed method as in computer simulations and support its feasibility in real ANC applications.