Damp by wire: magnetorheological dampers vs friction dampers

The paper reports a comparative investigation of a magnetorheological damper (MRD) and a friction damper (FD) in semi-active suspension design; both devices are closed-loop controlled. Experimentally validated models of both dampers have been developed and a hybrid variable structure-fuzzy control algorithm designed. It is shown that the two devices albeit based on very different physical principles, can be described by a general common mathematical model with the FD model being regarded as a particular case of the model for a MRD. Such analogy can be exploited in the design of the controller. The control strategy is targeted to improve occupant comfort. Performance has been investigated via numerical simulation in a quarter car vehicle model and compared to that obtained with a classical passive damper.