基于MICA的声级计频率计权数字IIR滤波器设计  

Design of Digital IIR Filter for Frequency Weighting in Sound-level Meters Based on Modified Imperialist Competitive Algorithm

作　　者：唐求[1] 吴娟 邱伟[1] 沈洁 滕召胜[1] TANG Qiu;WU Juan;QIU Wei;SHEN Jie;TENG Zhaosheng(College of Electrical and Information Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学电气与信息工程学院,湖南长沙410082

出　　处：《湖南大学学报（自然科学版）》2020年第2期78-84,共7页Journal of Hunan University:Natural Sciences

基　　金：国家重点研发计划资助项目(2016YFF0203400)。

摘　　要：针对双线性变换法在设计声级计频率计权数字滤波器时存在固有频率失真问题,提出一种基于改进帝国竞争算法的数字IIR滤波器设计方法.为避免帝国竞争算法出现早熟收敛而陷入局部最优的问题,在帝国竞争算法同化阶段引入混沌函数来增大搜索范围,与此同时,在帝国竞争阶段引入克隆进化算子,引导算法向IIR滤波器参数最优解方向搜索,得到改进帝国竞争算法.在研究声级计A、C计权的IIR滤波器误差来源的基础上,利用改进帝国竞争算法对声级计频率计权数字IIR滤波器系数进行寻优求解,构建基于改进帝国竞争算法的频率计权数字IIR滤波器优化模型.仿真与实验结果表明,本文提出的数字滤波器设计方法精度较高,且滤波器的误差能控制在10-3dB数量级范围内.在噪声环境下不同声信号级进行的频率计权测试结果表明,改进帝国竞争算法测试的声信号级的计权误差能维持在10-2 dB数量级范围内,完全满足国家标准GB/T3241—2010对1级声级计的设计要求.Aiming at the frequency distortion problem in the design of frequency weighting digital filter based on bilinear transformation,an evolutionary method based on Modified Imperialist Competitive Algorithm(MICA)has been proposed to design digital IIR filter.In order to help the algorithm to escape from local minima,this paper introduced a chaotic function to make the search range wider in the assimilation operation of Imperialist Competitive Algorithm(ICA).Meanwhile,a clone evolution operator was introduced in the competition operation,guiding the search for global optimization efficiently.Then,the optimization model of modified ICA of the filter in sound-level meter was designed based on the research of the source of error in IIR filter.The coefficients of frequency weighted were searched based on the MICA.The results of both simulation and application show the performance of the design method to find better solution,indicating that the proposed method can significantly improve the precision and the error can be controlled within the order of 10-3 dB.Finally,the test of frequency weighting under different acoustic signal level with noise verifies that the error of the MICA test can be maintained in the order of 10-2 dB,which fully meets the design requirements of sound level meter(Class 1)in the national standard of GB/T 3241-2010.

关 键 词：声级计 频率计权 数字IIR滤波器设计 帝国竞争算法 混沌函数 克隆进化 

分 类 号：TB52[理学—物理]