Realization of desired damping characteristics based on an open-loop-controlled magnetorheological damper

Abstract

The realization of the desired damping characteristics based on magnetorheological (MR) dampers is important for semi-active control and useful for the matching process of suspension damper. To reduce the cost of the control system and improve the output accuracy of the desired damping force, this study proposes an open-loop control method featuring an accurate inverse model of the MR damper and a tripolar current driver. The reversible sigmoid model is used to accurately and quickly calculate the desired current. Furthermore, the change characteristic of the desired current is analyzed qualitatively and quantitatively, which shows that the desired current needs to change suddenly to make the actual damping force velocity curve quickly approach the desired one. To meet the demand of the desired current, a tripolar current driver controlled by an improved PI control algorithm is proposed, which is with fast response and low noise. Finally, the bench test verifies that the control system can achieve different desired damping characteristics well, and the inherent error in this process is explained through the gap between the available damping force area and the desired damping characteristic curve and the crossover phenomenon of the dynamic characteristic curves of the MR damper.