The Application of MR Dampers in the Field of Semiactive Vehicle Suspension

Electrorheological (ER) and magnetorheological (MR) dampers are becoming to be used in the adaptive wheel suspension systems of serial-produced cars. If the adaptive system is fast enough (it can respond on high frequencies), it can be called semiactive. If the adaptive damper is supposed to work as semiactive, its response time should be approximately 10 times smaller than the reciprocal resonant frequency of the controlled system. From this point of view, the ER dampers are appropriate for semiactive suspension of both sprung and unsprung mass. MR dampers with standard low-voltage current drivers are too slow for semiactive suspension of unsprung mass. However the MR damper time response is mainly caused by coil induction and connected current driver. The time response of MR damper with the current driver with higher voltage should be fast enough even for semiactive suspension of the unsprung mass.