摘要
提出了一种利用最小二乘求逆计算的声学覆盖层吸声系数多通道逆滤波测量方法.该方法通过估计电路信道及水声信道的信道响应,利用最小二乘实现多通道逆滤波算法,通过多路逆信号的同步发射在声学覆盖层处实现高分辨率主瓣、低旁瓣和时域窄脉宽的入射波聚焦,从而提高声学覆盖层低频吸声系数的测量精度。仿真验证了该方法在混响抑制和空时聚焦中的效果.在压力水罐中进行了频率为0.8~5 kHz条件下的钢板试样反射系数和透射系数的测量实验,通过与理论计算值对比,验证了该测量方法的有效性。论文提出的方法适用于非自由场环境下声学覆盖层吸声系数的测量,尤其适用于低频条件下吸声系数的测量。
A method of measuring the absorption coefficient for acoustical coating samples using multichannel inverse filter using the least square method is proposed.First,the responses of the circuit channels and the underwater acoustical channels are estimated,and the retransmitted inverse signals for multiple transducers can be estimated with the least square method for solving the cost function constructed by the multichannel inverse filtering theory.Then,by retransmitting the inverse signals,the incident signal at the position of the acoustical coating sample is focused with high resolution,low level of side lobes and a narrow pulse signal in temporal domain based on the multichannel inverse filtering theory.The focus improves the measurement accuracy of the absorption coefficient for acoustical coating samples in low frequencies.The effect of the spatio-temporal focusing for the proposed method is demonstrated by simulations.The validity of the method is verified by experiments carried out in a cylindrical tank for a steel specimen at the frequency0.8-5 kHz.The experimental results show that the proposed method is effective to the measurement of the absorption coefficient for acoustical coating samples in non-free field,and is especially applicable to low-frequency measurements.
作者
马骁晨
李建龙
宋昊
李鋆
MA Xiaochen;LI Jianlong;SONG Hao;LI Jun(College of Information Science and Electronic EngineeringZhejiang University Hangzhou 310027;Key Laboratory of Ocean Observation-Imaging Testbed of Zhejiang Province Zhoushan 316021;Systems Engineering Research Institute of Chinese Shipbuilding Industry Beijing 100036)
出处
《声学学报》
EI
CSCD
北大核心
2019年第4期726-734,共9页
Acta Acustica
