CFRP层板缺陷红外热波雷达成像检测概率研究

Study on probability of detection for CFRP laminate defect using infrared thermal wave radar imaging

建立了Chirp调制激光激励的红外热波雷达成像检测系统,提出了基于分数阶傅里叶变换的Chirp锁相算法和基于希尔伯特变换时域积分的HT算法,实现了对CFRP层板缺陷的检测;合理设计了模拟缺陷的尺寸分布范围与缺陷判定准则,采用Hit/miss法分析了信号提取算法对检测概率的影响;给出了不同检测参数与判定阈值情况下,相关算法、Chirp锁相算法和HT算法提取结果的检测概率数据,确定了红外热波雷达成像系统对CFRP层板缺陷的检测概率水平。

An infrared thermal wave radar imaging system was set up to detect the internal CFRP laminate defects. Two novel kinds of signal extraction algorithms named Chirp lock-in algorithm and HT algorithm based on Hilbert transform and Fractional Fourier transform were developed in order to obtain the characteristic information of thermal wave radar signal. The defect size distribution range and criteria of defect judgment were designed reasonably. The influence of signal extraction algorithms on the probability of detection was studied by means of. Hit/miss analysis methodology. The POD curves obtained by the proposed algorithms at the designed testing parameters and thresholds were given. According to the probability analysis of detection, the probability level of CFRP laminate defects detection using infrared thermal wave radar imaging system were identified.