Disturbance rejection and force-tracking controller of nonlinear lateral vibrations in passenger rail vehicle using magnetorheological fluid damper

In this article, an existing railway vehicle is modelled as a full-scale nine-degree-of-freedom system considering lateral, yaw and roll motions of the car body and the front and rear bogies. Moreover, nonlinear stiffness and damping functions of passive suspension systems are extracted from experimental data. In order to improve the ride quality of the rail vehicle, a magnetorheological damper is integrated into the secondary lateral suspension system. Parameters of the magnetorheological damper depend on current, amplitude and frequency of excitations. Tracks with five different types of irregularity are considered for train speeds of 160 and 200 km/h. The track input is given to the multibody system in VI-Rail software and the wheel response is generated. The wheel motions are input to the mathematical model represented in MATLAB/Simulink. Four types of analyses are performed with (1) conventional passive lateral damper, (2) semi-active low, (3) semi-active high and (4) semi-active controlled MR lateral damper in the secondary suspension. Disturbance rejection and force-tracking damper controller algorithms were applied to control the desired force to reduce the lateral vibration. The results clearly imply that the proposed semi-active suspension system improves the vibration attenuation and ride quality of the vehicle.