Fotoohi A., Yousefi-Koma A.

This research is conducted to demonstrate advantages of skyhook semi-active dampers in railway vehicle suspension system. Semi-active suspension consists of four actuators on each bogie that locate in the secondary suspension position instead of passive dampers. Employing equations governing skyhook control policy, the semi-active damping force (actuator force) is determined by use of absolute velocity of car body instead of relative velocity. An integration of a control design tool, i.e. MATLAB, together with a tool for railway vehicle simulation, i.e. ADAMS/Rail is utilized for modeling and control analysis simultaneously. Analysis has been performed on a traditional model with passive secondary suspension and on a model with semi-active suspension. The effects of suspension system on displacement and acceleration in passenger seats have been investigated in various points of car body. Results show that semi-active suspension improves the ride comfort by reducing accelerations, in comparison with passive model. Skyhook dampers can improve the dynamic behavior of a railway vehicle and simplicity of skyhook damper implementations make them suitable for improve the performance in conditions that passive systems don’t act perfectly.