Ride comfort improvement of a railway vehicle by semi-active damping control – field tests

It is a commonly held view that semi-actively (S/A) controlled dampers can significantly improve the behaviour of a road and railway vehicles. Although simulation results published to date indicate potential improvements in railway vehicle ride comfort, this has not been sufficiently verified in real operation. This paper therefore investigates the effectiveness of S/A suspension control using magnetorheological (MR) dampers in improving the ride comfort of railway vehicle in real-world conditions. Field tests were carried out on a electric multiple unit , in which the conventional (passive) vertical and lateral dampers in the secondary suspension were replaced by MR dampers. These experiments were realized on three different railway lines that varied in terms of track alignment, maximum speed and quality. The results demonstrate that S/A control significantly improves ride comfort, especially at higher speeds and on poor-quality tracks. On standard lines, the mean comfort index NMV decreased by an average of 25%. The greatest benefit was achieved at the natural frequency of the vehicle body motion, where the vibration level is reduced by an average of 35%. Despite some challenges, this paper highlights the potential of S/A damping control to improve passenger comfort and makes a recommendations to further optimise its performance.