Design of a new gain-scheduled LPV/ℋ∞ controller for vehicle’s global chassis control*

This paper investigates new achievements in chassis control. Active Front Steering (AFS) and Direct Yaw Control (DYC) are optimized together to improve -at once- vehicle’s maneuverability, lateral stability and rollover avoidance. The novelty of this work with respect to other works in the field of chassis control is that the controller relies on one single centralized approach, where the additive steering angle provided by the AFS and the differential braking provided by the DYC are generated to control the vehicle yaw rate, side slip angle and roll motion. The optimal ${{\mathcal{H}}_\infty }$ control technique based on offline Linear Matrix Inequality (LMI) optimal solutions, in the framework of Linear-Parameter-Varying (LPV) systems, is applied to synthesize the controller. A decision making layer instantly monitors two criteria laying on the lateral stability and the rollover. It sends two endogenous weighted parameters, function of the vehicle dynamics, to adapt the controller dynamics and performances according to the driving conditions. The gain scheduled LPV/${{\mathcal{H}}_\infty }$ new control strategy is tested and validated on the professional simulator "SCANeR Studio". Simulations also show the advantage of introducing the roll motion and rollover criteria in the control architecture, comparing to other powerful controllers neglecting these features.