Optimal Linear Preview Control of Slow active Suspension Systems

Preview control is investigated for active suspension systems. Two preview concepts are used: (a) look-ahead preview, where the information relating to roadway disturbances about to be encountered by the moving vehicle is assumed to be sensed, and (b) wheelbase preview, where knowledge of the front wheel states is used to improve performance at the rear of the vehicle. An optimal preview control method is developed for application to half car suspension systems having full active and slow active vibration control elements. The slow active system used consists of an actuator of limited bandwidth in series with a passive spring, the combination being in parallel with a passive damper. Integral constraints are included in the performance index to achieve better body attitude control. The effect of preview control on vehicle performance characteristics in terms of ride comfort, suspension deflections, and road-holding ability is investigated