Semi-active Control of Automotive Vehicle Suspension System Using Magnetorheological Damper- A Review

The use of MR (magnetorheological) damper, as an active element in the vehicle suspension, has received a great deal of attention in the recent years. To use it efficiently one need to understand its characteristics. In this paper a review of characteristics of MR damper, by considering an elaborate mathematical model, is done. To use these controllable characteristics of damper, for isolation of sprung mass from the road excitations a controller is designed. In fact here two controllers are included; one is for the suspension system called system controller and the other for the damper. System controller uses a sliding mode control that takes care of loading uncertainties into account. In this paper attention has been devoted to review the idea how this kind of active element (active damper) are able to isolate without adding energy to suspension system. The skyhook damper is used as a reference model for sliding mode control, to transform a set point problem into a tracking problem and to provide required derivative signals. The performance of MR suspension system is also evaluated with bump excitation. The results show that designed MR suspension system is more effective when compared to a passive one.