Simulink Modeling and Control Analysis of a Two-Degree-of-Freedom Railway Vehicle System

This study establishes a Simulink model for a two-degree-of-freedom (2-DOF) railway vehicle system. The spatial frequency of the track irregularity power spectrum is initially converted to the temporal frequency domain, and then transformed into a time-domain signal through an inverse Laplace transform. Utilizing a Simulink-based modeling approach, time-domain simulations of irregularities for U.S. Federal Railroad Administration (FRA) Class 6 track are conducted. The obtained time-domain track irregularity signals are integrated into the Simulink-based railway vehicle dynamics model to perform simulation analysis of vibration characteristics in nonlinear passive suspension configurations. Under random track excitation, two novel control strategies are proposed: a linear relative control and a semi-active control based on magnetorheological (MR) dampers. Simulation analysis is conducted to evaluate the control effectiveness of both methods. The results demonstrate that the semi-active control using MR dampers exhibits superior performance compared to linear relative control, while the linear relative control outperforms the passive suspension system.