Fast Fourier Transform(FFT)frequency 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 ma...Fast Fourier Transform(FFT)frequency 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.展开更多
基金This paper is supported by the National Natural Science Foundation of China under Grant No.50705042Aeronautics Foundation under Grant No.2007ZB52022Jiangsu Provincial Universities and Colleges Fundamental Re-search Fund for Natural Science under Grant No.07KJD510132
文摘Fast Fourier Transform(FFT)frequency 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.