Potential of Low Bandwidth Active Suspension Control with Continuously Variable Damper

Abstract

Due to rising customer demands for driving comfort, the integration of controlled active and semi-active elements in modern vehicle suspension systems has increased considerably. A significant number of upper class vehicle suspensions is either equipped with continuously variable dampers or low bandwidth actuators. However, the combination of these suspension elements is not applied so far. In this paper active quarter car models are used to design time-invariant LQR controllers for specific road conditions. By optimizing the controller weights and damping ratio based on a new iterative optimization procedure, the potential of road adaptive low bandwidth systems with continuously variable dampers is clearly highlighted. It is shown that ride comfort can be significantly increased while satisfying given constraints for ride safety (maximum tire deflections) and suspension travel. The achievable performance is compared to passive and high bandwidth active suspension systems using carpet plots.