这个是直升机齿轮箱故障特征提取的程序。用的是小波变化加上hilbert包络的方法，简单实用，对大型旋转设备的故障检测有很广泛的应用！-This is a Helicopter Gearbox Fault Feature Extraction procedures. Changes using a wavelet plus hilbert envelope method is simple and practical, on large rotating equipment fault detection has a wide range of applications!