高精度波束形成的相控阵超声系统研究

发布时间：2018-04-14 15:20

本文选题：相控阵 + 波束形成　；参考：《传感技术学报》2017年03期

【摘要】：为深入研究管道环焊缝缺陷特性,需要相控阵检测系统提供完全控制激励信号参数和获得接收回波信号的特性,针对该问题设计了32个模拟通道,可接入128个阵元,数字化频率达到125 Msample/s的相控阵超声检测系统。采用流水线式延时实现小数倍延时,脉冲发射延时精度为2.5 ns;使用Master-Slave结构的管理方式,在硬件上合理分配资源,对回波数据进行线性插值,同时根据脉冲的延时方案对各通道的插值数据进行存储,实现高精度数字波束形成。使用Hilbert变换提取形成波束在FIR滤波器滤波前后的包络,得到滤波后信噪比提高了9.4 d B。对标准试块进行缺陷检测实验,实验表明在深度上缺陷定位的相对误差为1.7%,相对于现有系统检测精度提高了接近2倍。
[Abstract]:In order to deeply study the defect characteristics of pipe girth weld, the phased array detection system is needed to provide the parameters of fully controlled excitation signal and the characteristic of receiving echo signal. In order to solve this problem, 32 analog channels are designed, which can be connected to 128 array elements.A phased array ultrasonic detection system with digital frequency of 125 Msample/s.Pipeline type delay is used to realize fractional delay, the precision of pulse delay is 2.5 ns, the management mode of Master-Slave structure is used to allocate resources reasonably in hardware, and the echo data is interpolated linearly.At the same time, the interpolation data of each channel are stored according to the delay scheme of pulse, and high precision digital beamforming is realized.Using Hilbert transform to extract the envelope of beamforming before and after FIR filter filtering, the signal-to-noise ratio (SNR) is improved by 9.4 dB after filtering.The defect detection experiment on the standard sample shows that the relative error of defect location in depth is 1.7, and the accuracy is nearly 2 times higher than that of the existing system.
【作者单位】：天津大学精密测试技术及仪器国家重点实验室;中国石油天然气管道科学研究院;
【基金】：国家自然科学基金项目(51375338)
【分类号】：TB55

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