导波信号处理算法研究.doc

 PAGE \* MERGEFORMAT  导波信号处理算法研究 摘要:研究导波信号处理方法，根据其传播规律以及信号特征，设计算法，使其能够检测陶瓷保护管的缺损，并且不损坏被检测物品。通过对超声回波信号的读取，以及构造单频窄脉冲信号，对原始回波信号进行匹配滤波处理，再通过对截取波做相关处理和希尔伯特变换，得出时差，最终算出声速。 对其研究的目的就是通过一种简便的方法，能够准确无误的定位缺损部位，从而能够进行无破坏，全面，全程的检测。对其主要的研究方法就是通过对超声导波信号的特征分析，采用相关和时延的方法，而关于其的研究成果的展示方式就是编写算法，然后在基于matlab的图像中分析数据，从而得出研究结果。对于导波信号的研究，本质就是需要我们了解导波的特性，利用导波在传播过程中的特点以及方式，以数值计算的方式使得缺陷检测得到实现。在其过程中，我们需要用到的研究方法很多，要知道关于超声导波在管道中匹配滤波时会产生的频散和噪声等，从而要选择适当的方式对其进行必要的处理，使其产生的结果能够清晰明确的展现出我们需要的研究的一面，从而使之后的进一步关于检测的处理能够很顺利的进行。 在这里，首先就要明确编写的算法本质就是对于导波信号的处理过程的展示，只有经过对其不断的调试和修改，在其所实现的图中将需要得出的结果能够很明确的表现出来，就实现了对其一系列研究的目的。 关键词：互相关函数，时延估计，希尔伯特变换，缺陷检测  PAGE \* MERGEFORMAT 28 Research on Algorithm of guided wave signal processing Abstract：Study of guided wave signal processing method, according to the propagation rules and the signal features, algorithm design the detection of ceramic protection tube defects can, and does not damage the test items. Through reading the ultrasonic echo signal, and structure of single frequency narrow pulse signal, on the original echo signal matched filter processing, through correlation and Hilbert transform to intercept the wave and time difference is obtained, finally calculate the speed of sound. The research purpose is through a simple and convenient method, can be accurately locating the defect site, so as to be able to without damage, comprehensive, full detection. The main research methods is through of ultrasonic guided wave signal characteristic analysis, using method of correlation and delay, and Research on the display mode is to write algorithm. Then based on the MATLAB image analysis data, and obtains results. For guided wave signal, in essence, is the need to our understanding of characteristics of guided waves, wave characteristics in the propagation process and ways of using pilot, by numerical calculation of the way the defect detection by Now. In the process, we need to use many research methods, to know about the guided wave in pi