Design of a control law for a magneto-rheological suspension

In this paper we present a design procedure for semiactive suspensions of road vehicles, where the shock absorber (damper) uses magneto-rheological fluid instead of oil. We first derive a target active control law that minimizes a quadratic performance index and takes the form of a feedback control law. Then, we approximate the target law by controlling the damper coefficient f of the semiactive suspension. The nonlinear characteristics force-velocity of the damper are used to approximate the target law. To improve the efficiency of the proposed system, we take into account the updating frequency of the coefficient f and compute the expected value of f using a predictive procedure.