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基于Leaky-LMS算法对宽带噪声的控制

2019-10-21高坤,史晨路,吕晓,祖炳洁

汽车实用技术 2019年23期

高坤,史晨路,吕晓,祖炳洁

摘 要:Leaky-LMS算法是传统LMS的改进算法,该算法主要适用于随机性较强的宽带噪声,该算法解决了传统LMS算法收敛性、稳定性和瞬态特性的固有缺陷,同时它在系统辨识方面也有很多应用。文章详细介绍了Leaky-LMS算法的推导过程,并分析了该算法的收敛性和稳定性。同时通过MATLAB仿真,比较了传统LMS算法和Leaky-LMS算法对宽带噪声的控制效果。仿真结果表明,Leaky-LMS算法的稳定性、收敛性和瞬态特性要优于传统LMS算法,有效的对汽车车内宽带噪声进行控制。

关键词:泄露LMS算法;收敛性;稳定性;瞬态特性;MATLAB仿真

中图分类号:U462.3  文献标识码:A  文章编号:1671-7988(2019)23-167-03

Leaky-LMS Algorithm Based on Broadband Noise Control

Gao Kun1,2, Shi Chenlu1, Lv Xiao1, Zu Bingjie2

( 1.China Auto Research (Tianjin) Automotive Engineering Research Institute Co. Ltd., Tianjin 300000;2.Shijiazhuang Railway University, Hebei Shijiazhuang 050043 )

Abstract: Leaky-LMS algorithm is an improved algorithm of traditional LMS, which is mainly applicable to broadband noise signals with strong randomness. This algorithm solves the inherent defects of convergence, stability and transient characteristics of traditional LMS algorithm, and also has many applications in system identification. Leaky-LMS algorithm was introduced in detail, its convergence and stability were analyzed, and the control effect of broadband noise by traditional LMS algorithm and leaky-LMS algorithm were compared by MATLAB simulation. Simulation results show that leaky-LMS algorithm has better stability, convergence and transient characteristics than traditional LMS algorithm, and effectively controls the wideband noise in cars.

Keywords: Leak LMS algorithm; Convergence; Stability; Transient characteristics; MATLAB simulation

CLC NO.: U462.3  Document Code: A  Article ID: 1671-7988(2019)23-167-03

前言

隨着NVH控制手段的不断进步和数字信号处理芯片运算能力的提升,主动控制技术越来越多的应用在车内噪声控制中。传统的最小均方(LMS)算法由于良好的自适应性能被广泛的应用到汽车主动降噪领域。由于LMS算法的固有属性,该算法的收敛性和稳定性不能同时满足,当步长因子较大时,可以提高收敛速度,但是稳定性变的较差;当步长因子较小时,可以提高稳定性,但是收敛速度变的较慢。特别是对于随机性较强的宽带信号,LMS算法的瞬态特性会较差。

Leaky-LMS算法可以解决LMS算法的固有缺陷,该算法可以限制瞬态输出信号,并可以同时提高控制系统的稳定性和收敛性。

1 介绍

最小均方(Least Mean Square LMS)算法是由Widrow和Hodff在1960年提出来的[1][2]。该算法简单并易于实现,对自适应系统具有良好的处理能力,所以被广泛的应用在汽车主动降噪领域。……

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