一种调节反馈有源噪声控制系统水床效应的频域自适应算法  

A frequency domain adaptive algorithm for tuning the waterbed effect of feedback active noise control system

作　　者：吴礼福[1,2] 李佳强 陈定 郭晓董 焦坤 WU Lifu;LI Jiaqiang;CHEN Ding;GUO Xiaodong;JIAO Kun(School of Electronic & Information Engineering,Nanjing University of Information Science & Technology,Nanjing 210044,China;Jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学电子与信息工程学院,南京210044 [2]江苏省大气环境与装备技术协同创新中心,南京210044

出　　处：《应用声学》2019年第1期45-51,共7页Journal of Applied Acoustics

基　　金：国家自然科学基金项目(11504176)

摘　　要：伯德灵敏度积分决定反馈有源控制系统具有水床效应,即某个频段内的噪声衰减伴随着另一频段内的噪声放大。已有的反馈系统自适应算法没有明确考虑噪声放大量,非自适应算法考虑了噪声放大量但不能在线调整。为了使自适应反馈系统能明确调节噪声放大量,该文以控制器某个频段内的幅度响应小于指定阈值为约束条件,并作为"惩罚项"与误差信号能量相加得到代价函数,通过最速下降法最小化该代价函数得到了一种频域自适应算法。与已有算法在有源降噪耳机实例中的对比结果表明,该算法能够更为直接地对指定频段内的噪声放大量进行调节,从而在降噪量与噪声放大量之间取得折衷。The waterbed effect of the feedback active noise control system is determined by the Bode’s sensitivity integral,which states that if the noise is attenuated at some frequencies,there is always some noise amplification at some other frequencies.The offline design methods for the feedback active noise control system take the noise amplification into account,but they are not adaptive,the adaptive systems do not consider the waterbed effect explicitly.A frequency domain filtered-x least mean square algorithm is introduced to tune the noise amplification in this paper where a constraint that limits the gains of the controller filter at some discrete frequencies are defined and merged into the error signal energy as a penalty term to obtain the new cost function,the update equation of the controller filter is given by minimizing the new cost function with the steepest descent method.Simulations in an active noise control headphone application show that the proposed algorithm can tune the noise amplification more effectively than the existing algorithms.

关 键 词：有源噪声控制 自适应滤波 水床效应 

分 类 号：O429[理学—声学]