这是关于小波特征变换，其中这里的提取特征分为几个一是零中心归一化瞬时幅度的频谱最大值，二是包络平方值的两倍包络均值平方之差。三是瞬时频率的方差。四是大小波系数的方差，五是信号的四阶累积量之比。-This is the wavelet transform features, which extract features here is divided into several one is zero center normalized spectral maximum of instantaneous amplitude, the second is twice the value of the envelope squared envelope of the mean squared difference. Third, the variance of the instantaneous frequency. Fourth, the coefficient of variance of the size of the wave, five are fourth-order cumulant ratio of the signal.