根据实际系统超声信号的普罗尼分析结果,提出了基于双指数线性组合的超声信号经验模型,分析了上升时间和半峰宽特性,给出了模型参数确定方法.对双指数模型和混合指数模型的拟合精度与TOF估计方差进行了对比分析,结果表明双指数模型更适于描述半峰宽与上升时间比值大于2.5的超声信号.

Based on the analysis results of ultrasonic signal acquired in an actual system,an empirical model named double exponential model using the linear sum of two exponentials is proposed.The full width half maximum and the rise time of double exponential model are analyzed,and the methods of model’s parameters estimation are introduced.Further the fitting accuracy and TOF( time of flight) estimation variance of double exponential model are compared to those of hybrid exponential model.It is shown that the double exponential model is suitable for the ultrasonic signal in which the ratio of the full width half maximum and the rise time is more than 2.5.