Time-Frequency characteristic analysis of track irregularity of high-speed railway

The time-frequency characteristics of a vibration signal,measured on some high-speed railway,was given by short time Fourier transform(STFT),Wigner-Ville distribution(WVD)and Gabor transform. The most disadvantage irregularity wavelength,under uniform conditions,was extracted by the result of STFT. Because of the contradiction between time and frequency resolution,an improved STFT was raised to analyze the time-frequency characteristics of the signal.The results show that the vibration frequency of long-wave irregularity is synchronized varying according to the train speed,and the improved STFT can successfully extract the long-wave irregularity characteristic frequency.