基于平面波分解的封闭空间次级声源布局优化

Optimization of secondary source configuration in enclosure using plane wave decomposition

封闭空间有源噪声控制系统的次级声源布局优化一般只关注离散点的降噪需求,导致空间区域降噪效果不理想,而且需要预先知道误差传感器布局信息。为解决该问题,提出一种面向空间降噪的代价函数。利用声场的平面波分解,获取初级声场平面波和各备选次级声源的单位次级声场平面波作为布局优化先验信息,以此构造波域有源控制代价函数,优化方法采用模拟退火搜索。以刚性壁矩形腔为对象,利用波域先验信息解析值与2种空间域布局优化方法结果做比较,表明所提方法在不依赖于误差点位置信息的情况下,能获得更优的空间声势能降噪效果;利用随机分布的传声器测量估计波域先验信息做布局优化,结果说明实际中所选布局能够达到比空间域方法更优的空间声势能降噪效果,但测量传声器位置对结果影响较大。

The optimization of secondary source configuration for an active noise control(ANC)system in its enclosed space generally focuses on noise reduction requirements at discrete points only.This may lead to the poor noise reduction performance in the whole spatial region,and it is necessary to know the information on error sensor positions in advance.To address this problem,a cost function for spatial-region-oriented noise reduction is proposed.The plane wave decomposition of the enclosed sound field is used to obtain the primary field plane waves and the unit secondary field plane wave of each candidate secondary source as the prior knowledge for configuration optimization,so as to formulate a wave-domain ANC cost function.The optimization method adopts the simulated annealing search.Taking a rigid-walled rectangular cavity as an example,the optimization method is firstly compared with two space-domain methods by using analytic values of the wave-domain prior knowledge.The comparison results show that the better reduction of spatial acoustic potential energy can be achieved independent of the error sensor configuration information.Then the estimated values of the wave-domain prior knowledge through measuring randomly distributed microphones are used to optimize the configuration of the ANC system.The optimization results suggest that the noise reduction of spatial acoustic potential energy of the optimized configuration can be better than that of the space-domain method,but the microphone positions have a great influence on the noise reduction performance.