A smart solution for improving ride comfort in high-speed railway vehicles

The secondary suspensions of high-speed trains are designed to guarantee high comfort levels to passengers by reducing the perceived vibrations. Recent studies have shown that, besides the vertical and rigid pitch motions, the first deformable modes of the car-body are very important when dealing with comfort. Therefore, the suspension damper has to offer high performances at low frequencies, but at the same time, has to transmit low force at high frequencies. To achieve this target, in this work, a traditional passive oil damper was modified. A proper servo-valve was installed between the two chambers of the damper, and three different control logics were studied. A hardware-in-the-loop test bench was created and the proposed solutions were compared in terms of comfort improvement.