Abstract:In order to extract dynamic characteristics of vehicle-track coupling system, the Improved Empirical Mode Decomposition was presented. In this method, extremum points envelopment mean were replaced by improved extremum field mean and the boundary wave matching algorithm was used to restrain the end effect. Based on the theory of vehicle-track coupling dynamics, the vertical vehicle ballastless-track coupling dynamics model was established. Under the rail corrugation and rail irregularity excitation model, dynamic responses of vehicle-track coupling system were calculated at different speed. These dynamic responses were decomposed by Improved Empirical Mode Decomposition, and then the intrinsic mode functions of vertical contact force, bogie acceleration, and car body acceleration were analyzed and compared. The results show: the Improved Empirical Mode Decomposition can self-adaptively decompose vibration signals to intrinsic mode functions and so effectively extract dynamic characteristics of vehicle-track coupling system.