高阶累积量在红外热像损伤检测信号分析中的应用

针对常规红外检测信号的脉冲相位法没有考虑测量噪音，简单的Fourier变换对数据信息的挖掘不足、利用率不高的问题，提出在处理中引入非高斯特性分析，应用三阶累积量和双谱估计对信号进行分析，提取发生损伤时信号的特性信息，得到分辨完好区域与损伤区域的特征判据。给出信号分析中三阶累积量和双谱的定义，分析其幅值和相位的对角切片谱在提取损伤特征方面的优势，最后对比分析两者在实际检测中的效果。结果表明:利用该方法具有良好的抗高斯和非高斯对称分布型噪音的优点，且运算量小、计算速度快。同时，弥补了传统脉冲相位法中幅值谱不宜使用的缺点。

Application of higher order spectral analysis in infrared thermography damage signal processing

In the routine infrared inspection signal processing, pulse phase thermography doesn't take into account the measure noise, the experimental data isn't made good use of by the simple Fourier transform, where more information needs to be dig. The non-Gaussianity analysis was introduced to the routine signal processing, the third-order cumulant and bispectrum estimation were used for extracting the characteristic information from the detection signal when damage occurred, therefore the criterion of distinguishing sound area from defective area was obtained. The definitions of third-order cumulants and bispectrum were achieved for the acquired signal, in addition, the advantage using magnitude and phase of slice spectrum was analyzed and the effects were compared in actual detection. The proposed method has the advantages of suppressing Gaussian and symmetry distribution non-Gaussian noise efficiently, small calculation amount, fast computation speed. Moreover, it compensates the demerit which magnitude of spectrum is hard to use in the traditional pulsed phase thermography.