Multi-Objective Road Adaptive Control of an Active Suspension System

In the design of automobile suspension systems, the classical conflict between minimizing vertical chassis acceleration to increase passenger comfort and keeping the dynamic wheel load small in order to ensure safe driveability must be further eased due to increasing customer demands. In order to moderate the conflicting suspension objectives, a switching controller structure for an active suspension system is developed which schedules linear optimal regulators depending on the present dynamic wheel load and suspension deflection. The goal is to maximize ride comfort while the wheel load is below certain safety critical bounds and the suspension deflection remains within given construction-conditioned limits. Stability of the switching control system is analyzed using a multiple Lyapunov function approach. The performance of the road adaptive suspension control system is compared with a linear controller and the passive suspension system in simulations to point out the benefits of the developed control concept.