Active Suspension Controller using MPC based on a full-car model with preview information

Active suspension systems in vehicles provide the possibility to overcome the trade-off between ride comfort and handling characteristics of passive systems. Active suspensions have even greater potential if preview information of the oncoming road height profile is available. This paper presents a control strategy for vehicles with active suspensions and available preview information, which has to be obtained by a sensor mounted in front of the car. The controller is based on a full-car model. To incorporate all hard constraints on control variables, a Model Predictive Control (MPC) design scheme is applied. Since wheel dynamics are not within the bandwidth of energy-saving, low bandwidth active suspension systems, the controller is based on the idea, that only vehicle body dynamics and not wheel dynamics should explicitly considered in controller design. Accordingly the cost function of the controller considers only the minimization of vehicle body accelerations and hence the improvement of ride comfort. It is shown, that all the same, handling characteristics are also improved.