Wavelet Transform Based On The Frequency Slice Rail Wheel And Rail Vibration Signal Analysis

Wheel-rail coupling vibration make a difference to the operation safety of train and the ride comfortability of passengers, so it has a high academic value and practical significance to do research to the wheel-rail vibration signal. Base on the previous studies, a reasonable vehicle-track vertical coupling dynamics model was established in this paper. In addition, the simulation data and the measurement data were analyzed based on frequency slice wavelet transform (FSWT) theory.Firstly, the practical significance and development status of railway vehicles safety monitoring were described, and the research actuality of vehicle-track dynamics model and wheel-rail vibration signal were summarized.Secondly, the mechanism of wheel tread flat and track vertical irregularity was analyzed. The common analyzing methods of vehicle-track dynamics signal were discussed, including characteristic parameter method, Fourier transform, short-time Fourier, wavelet transform and Wigner-Ville Distribution time-frequency method. The advantages and disadvantages of each method were compared through simulation.Thirdly, the vehicle-track vertical coupling system model and its excitation model were discussed. The input form of the model of flat scar excitation and track irregularity was analyzed deeply, and numerical simulation of track irregularity was made. Vehicle-track vertical coupling dynamics model was established and compared with the output results of the dynamics simulation software Adams/Rail to verify its rationality and validity.Fourthly, the FSWT theory was researched in detail. The basic concepts of FSWT was introduced, and its time-frequency characteristics were studied. Then the method of choosing frequency slice function and determining the scale factor were given. The simulation results were given to verify the feasibility and advantages of FSWT in time-frequency analysis.Finally, the simulation data of vehicle-track vertical coupling dynamic model and the actual vibration measurement data from wheel axle box were used to analyzed based on FSWT. The results validated the reasonability of the established model and the feasibility of FSWT theory in wheel-rail vibration signal analysis.