一种抑制超声换能器拖尾信号的方法

Method for Suppressing Tailing Signal of Ultrasonic Transducer

超声换能器在脉冲信号激励下产生的拖尾信号,在进行短距离的超声测量时,容易淹没有效的回波信号,从而产生测量盲区。为了最大限度地减小拖尾信号,从构造超声换能器的等效电路入手,建立超声振动输出与激励输入之间的传递函数。利用传递函数仿真分析激励时叠加的反向周期数与拖尾信号抑制程度的关系。发现通过叠加特定周期数的反向正弦激励信号,可以将换能器模型的拖尾信号幅度抑制到最低。实验与计算分析发现,当所设计的实验系统的激励信号叠加3.8个反向周期时,对超声换能器的拖尾信号的抑制效果最佳。

Ultrasonic transducer generates a tailing signal after launching a signal,in short⁃range ultrasonic measurements,effective echo signals were easily submerged in the trailing signal,causing measurement blindzone.In order to minimize the meas⁃urement blindzone,an equivalent circuit of the ultrasonic transducer was constructed,and its transfer function was established.The relationship between superposition of the reverse sinusoidal signals and ultrasonic tailing signal by simulating the transfer function was established.It is found that by adding to the reverse sinusoidal signals of specific cycles,the amplitude of tailing signal is sup⁃pressed to minimum degrees.It has been experimentally verified that the amplitude of tailing amplitude could be suppressed to a minimum when 3.8 reverse cycles are added.