Efficient dynamic modelling and characterization of a magnetorheological damper

The present work is about the dynamic modelling and the experimental testing of magnetorheological (MR) dampers, especially at low frequency. The main improvement of this work over former models is the identification of dynamic parameters which are independent of the working conditions and vary only as a function of the current. A simple model is built on the basis of the literature and of a systematic experimental campaign, with the aim of simplifying the effort in retrieving the parameters and in controlling the system. The excitation current is introduced in the model as a variable, not only reducing the amount of test needed to assess the parameters, but also obtaining a faster model useful in motion control. A second order polynomial relationship between the applied current and the three variable parameters is found, showing a saturation effect at high currents. A verification test shows the reliability and the performance of the proposed model.