Study on semi-active suspension applied on carbody underneath suspended system of high-speed railway vehicle

Considering the coupling vibration of a flexible carbody and the underneath suspended equipment, a vertical coupled vibration model of a high-speed train was constructed. A roller test rig was conducted to validate the theoretical model. To reduce carbody elastic vibration, the semi-active vibration reduction models based on the Sky-hook and the linear quadratic regulator control strategies were proposed. The semi-active suspension system was installed between the carbody and the suspended equipment, and the influence of the semi-active suspension on carbody vibration reduction was analyzed. The results show that the semi-active suspension can significantly reduce carbody vibration, especially at high operating speeds. The higher the elastic vibration of carbody, the better the vibration reduction effect of the semi-active suspension. Compared with the passive suspension and the semi-active suspension, the semi-active suspension of the Sky-hook control has a relatively wider vibration control range, and has an obvious effect on carbody rigid and elastic vibration reduction. Although the semi-active suspension of the linear quadratic regulator control had little influence on the rigid carbody vibration, it could reduce most of the elastic carbody vibration.