Comparing RWS and RAD approaches in robust vehicle yaw control

A comparison between two different approaches to vehicle stability control is carried out, employing a robust non parametric technique in the controller design. In particular, an enhanced Internal Model Control strategy, together with a feedforward action and a suitably generated reference map, is introduced for the control of a vehicle equipped with a Rear Wheel Steering system and one equipped with a Rear Active Differential device. The uncertainty arising from the wide range of operating conditions is described by an additive model set employed in the controller design. Comparison of understeering characteristics, stability over low friction surfaces, damping properties in impulsive manoeuvres and disturbance rejection are shown through simulation results performed on an accurate 14 degrees of freedom nonlinear model.