Enhancement of Semi-active Vehicle Suspension System Performance Using Magnetorheological Damper

Vehicle suspension is considered a vital system of modern automotive and necessary to offer an adequate level of ride comfort and roadholding. In the present paper, a fuzzy-based sliding surface (FBSS) controller is designed, as a system controller for the first time, for a semi-active vehicle suspension using a magnetorheological (MR) damper in order to minimize the transmitted unwanted vibrations to the passengers. Therefore, an ideal reference skyhook model is employed to construct the sliding surface, which is the input of fuzzy logic. MR damper is a semi-active device and is controlled indirectly using an external voltage source. So a neural-based damper controller is used to compute the applied voltage to the magnet coil of the MR damper in series with the FBSS system controller. The proposed semi-active controlled quarter-vehicle suspension using an MR damper is solved numerically by Matlab. Simulation results are generated in time and frequency domains to judge the suspension system efficacy under different road profiles. Finally, the results indicated that the proposed semi-active MR suspension system controlled using FBSS offers an outstanding improvement of ride comfort and roadholding in comparison with the passive, uncontrolled MR and also controlled using linear-quadratic-regulator (LQR) suspension systems.