The weak feature of rolling bearing incipient fault can be extracted by a new method which combined a nonlinear transformation and morlet wavelet demodulation.Firstly,the vibration signal of rolling bearing is preprocessed by nonlinear transformation method to enhance the signal-to-noise ratio,and select an optimal transform times by spectral kurtosis as the estimate rules.Then, demodulate the output signal of nonlinear transformation by morlet wavelet with appropriate scale to get the fault characteristic ...