An Experimental Study of Time-Varying Step-Size Methods for Active Noise Control Systems with Online Secondary Path Modeling

• Main Authors: Kuan-Cheng Chi, 紀寬政
• Other Authors: 林忠逸
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/98468601502410166002

碩士 === 國立中興大學 === 機械工程學系所 === 102 === In active noise control (ANC) system with online secondary path modeling, the performance of ANC system will be influenced by the estimation accuracy of the secondary path. In order to increase the accuracy of the discriminator, we can use variable-step-size algorithms or adding a compensator to enhance the fast convergence and performance of ANC system. In this study, we used computer simulations and experimental studies to discuss the differences of constant step-size and time-varying step-size base on NLMS algorithm. It is found that exponential decay step-size(EDSS), constant step-size(CSS) and optimal variable step-size(OVSS) based algorithm all have good performance from simulation results, but only OVSS based algorithm can resist the situation of Environmental changes. OVSS based algorithm has faster convergence than CSS and EDSS based algorithm from experimental results, and it also can be convergent when noise source is change. Although the noise reduction in experimental studies is lower than simulation results, but we can know that OVSS based algorithm has better robustness and adaptability than CSS and EDSS based algorithm.