Analysis and Study of Modern Fault Diagnosis Methods of Mechanical Equipments

Fast Fourier Transform(FFT)fiequeney spectrum analysis,signal decomposing and reconstruction by wavelet analysis,fractal theory and chaos theory are hot research topics for fault diagnosis and prediction of complex machinery so far.In this paper,the characteristics of the FFT method.wavelet method,fractal method,and largest Lyapunov exponent method are studied and analyzed in detail.The advantages and shortcomings of these methods are pointed out respectively.Some unsolved problems are presented here.