Performances improvement through an LPV/H∞ control coordination strategy involving braking, semi-active suspension and steering Systems

This paper proposes a new multivariable design strategy for Global Chassis Control, using LPV/H_∞ robust controllers of semi-active suspension, active steering and electro-mechanical braking actuators. The proposed solution is a two stages control scheme: on one hand, rear braking and front steering to enhance the vehicle yaw stability and the lateral dynamics, and on the other hand, semi-active suspensions to improve comfort and car handling performances. The main idea of the strategy is to schedule the 3 control actions (braking, steering and suspension) according to the driving situation evaluated by a specific monitor. The main result of this paper is to propose a “LPV” strategy that aims to enhance vehicle performances by generating a hierarchical activation of the 3 controllers in critical driving situations. Simulations are carried out on a complex full vehicle model equipped with Magneto-Rheological Dampers characteristics subject to critical driving situations. A comparison between the proposed “LPV” strategy with the “LTI” case confirms the effectiveness of the proposed control strategy.