Magnetorheological fluids are widely used as their rheological behavior can be reversibly changed with simplicity. These fluids have important applications in the field of damping systems. In the paper a brief description of their properties is given at first. Then, problems in designing magnetorheological (MR) dampers caused by the nonlinear behavior of these MR dampers are examined with regard to accuracy and implementation of the models proposed in literature. Finally it's described in detail a new measurement method that has been thought by the authors to characterize and then control magnetorheological dampers for automotive applications.

Active and semi-active suspension systems allow to obtain the best compromise between ride comfort and road holding. These systems analyze signals describing the vehicle status and react to unwanted vibrations on the basis of the control strategy. The analysis of the signals in the frequency domain can improve the control action, since incoming vibration can be properly detected. In this paper a method for the detection of incoming frequency components in real-time is proposed and is used in analyzing a Magneto-Rheological suspension system.