具有自保护功能的超声导波回波检测系统的设计与实现

针对超声导波检测设备采用Pulse-echo工作方式进行结构无损检测时,需检测到数百伏高压激励脉冲的发射时刻和数毫伏至数百毫伏回波信号的特点,设计了具有自保护功能的回波检测系统,该系统主要包括自保护电路、前置放大电路、滤波电路、程控放大电路和A/D转换电路等部分,通过DSP+FPGA构成一种易扩展的方式来实现检测过程的控制.试验结果表明,该系统能实现自保护、检测精度高,具有一定的实用性和推广价值.

Design and Implementation Self-protection Function of Echo Inspection System With for Ultrasonic Guided Wave

When the ultrasonic guided wave testing system is applied for nondestructive inspection of the structure and work in pulse-echo mode,the amplitude of the excitation pulse going into the transducer will be hundreds of volts while that of the received signal is from several millivolts to hundreds millivolts.According to this characteristic,an echo detection system with self-protection function was designed.The system included self-protection circuit,preamplifier,filter circuit,program-controlled amplifier,A/D converter circuit and so on.The detection process of the system was controlled by DSP + FPGA.The experimental results show that this system can achieve self-protection and precision testing,which is valuable in practice and can be used widely.