Application of oil-hydraulic actuator for active suspension of railway vehicle: experimental study

The application of oil-hydraulic actuators for active suspension of railway vehicles has been examined experimentally by using a 3-DOF half-vehicle model. The LQG control law was adopted, in which state variables were estimated from measurable ones on the actual railway vehicle. The results show the possibility that the controllable frequency range extends with the oil-hydraulic actuator. The addition of bogie acceleration measurement to body related measurement provides a significant advantage for the performance. When actual body weight becomes lighter than that of the controller design value, the control performance and the stability deteriorate. Therefore, it is recommended to use the empty car body weight for design of the active suspension controller. The control effect can reach to the maximum vibration isolation level by shortening the sampling period to 2 ms.