基于参数化模型的液体声参量估计方法

Estimation of the sound parameters for the liquid based on parameter model system identification method

为快速、准确地对液体材料的声衰减系数及声速进行估计,提出了一种基于参数化模型的液体材料声参数估计方法。建立了声波在液体介质中传输的参数化线性系统模型,通过脉冲回波实验测得液体材料的回波,结合系统辨识得到声波的传输函数,根据传输函数与声参量的解析表达式对材料的声参量进行估计。结果显示:利用参数化模型方法,可以获得液体材料声参量较为精确的估计;声衰减系数与频率平方成正比,声速随频率缓慢变化。

In order to estimate sound attenuation and sound velocity of the liquid material quickly and accurately, a parametric estimation method of liquid material based on parametric model is established. By establishing the parametric linear system model of the liquid material, the rapid estimation of the liquid sound attenuation and the sound velocity in the effective band can be obtained. The echoes of the physiological saline solution are measured by pulse-echo experiments. Using system identification method, the transfer function of the saline is obtained. Thus according to the analytical relationship of transfer function with sound attenuation and sound velocity, the acoustic parameters can be estimated. The estimation results showed that sound attenuation is proportional to the frequency, while the sound velocity varies with frequency with a slow trend. The more accurate estimation of the liquid materials can be obtained by this parametric method.