【摘要】 近年来超声相控阵检测技术正逐渐成为国际无损检测领域的研究热点之一。目前国内外的超声相控阵系统结构复杂、集成度较低。基于FPGA技术,将系统延时算法模块与时序控制模块进行单片集成,基于串行发射方式提出了一种在单片电路上实现多通道相控阵超声发射系统的设计方案,从而提高了系统硬件集成度。运用DSP Builder完成了延时算法的运算及测试。利用数字波形发射方式使得激励信号参数及相位延迟任意可调,实现了高精度的延时控制,提高了缺陷检测的分辨率和信噪比。系统主要包括信号发生模块、信号调理模块及接收模块。试验结果表明:该系统工作性能稳定,延时精确度高,对超声相控阵发射系统的优化具有重要的意义。更多还原

【Abstract】 Ultrasonic phased array technique has been highly recognized in NDT( Non-destructive testing) of structure research domain in the recent years. As the weakness that the current phased array detecting system usually has a complicated structure and low integration,by adopting the serial transmitting way based on the technology of FPGA. This paper presented a design project which can achieve multi-channel ultrasonic phased array transmission with a single chip. The system is integrated by time delay algorithm and sequential control module,thus the integration of hardware would be improved. The operation and test for time delay algorithm was done by DSP Builder. The SNR and resolution of defect detection were improved,since it made the excitation signal parameters and phase delay arbitrary adjustable by using transmitted waveforms and finally achieved a high precise control of time delay. The system includes the signal generation module,the signal processing module and receiving module. The result shows that the system has a stable performance and a high accuracy of delay,it is an effective approach to optimize the ultrasonic phased array inspection system.更多还原