Optimal Preview Control of Active Suspensions with Integral Constraint

In this paper we consider the application of stochastic optimal control theory to the design of an active vehicle suspension with preview control. An integral constraint is included in the performance index to achieve better attitude control characteristics. The two-degree-of-freedom vehicle model travels with constant velocity on both random and deterministic roadways. Information relating to roadway disturbances about to be encountered by the moving vehicle is assumed to be sensed and this information is used by the active control scheme to prepare the system for the ensuing input. We examine the effect of preview control on vehicle performance characteristics in terms of ride comfort, suspension deflection, road-holding ability, control force, and power requirements. The performance characteristics of the devised multivariable controller are evaluated and compared with those of the pertinent active suspension systems based on state variable feedback and conventional passive systems.