【摘要】 为了解调出带有裂缝信息的微弱超声信号,提高激光外差干涉法探测材料表面裂缝的能力,研究了利用小波变换实现激光外差干涉微裂缝信号的相位解调算法,并将小波变换算法运用到实验获得的零差信号,提取出超声信号,得到了被测样件裂缝的位置信息.实验结果表明:利用小波变换算法得到的被测样件裂缝的距离与实际距离的误差率为2.40%,验证了算法的可行性和准确性.更多还原

【Abstract】 In order to demodulate weak ultrasonic signal with micro-crack information and enhance the ability of laser heterodyne interferometry to detect the surface micro-crack,a discussion on the phase demodulation algorithm using the wavelet transform for laser heterodyne interference micro-crack signal was presented.The homodyne signal was obtained from the experiment by using the wavelet transform algorithm,meanwhile the ultrasonic signal was extracted and the position information of the micro-crack was obtained.The experimental results show that the error rate of the distance between the actual distance and the distance of the micro-crack obtained by the wavelet transform algorithm is 2.40%,which verifies the feasibility and accuracy of the algorithm.更多还原