Influence of Drive Force Distribution on the Lateral Grip and Understeer

The increased freedom of control, when compared to traditional driveline configurations, enables the vehicle for instance to maintain characteristics from the linear tire operating range up to the grip limit. However, based on the review of the current state of the art and the importance of factors such as lateral grip and understeer, the authors see a need for improved (graphical) methods and theory describing the influence of drive force distribution on these said factors. In this work the results used to compute the lateral grip margin for a general drive force distribution was developed for four special cases; front-wheel drive; rear-wheel drive; all-wheel drive with synchronous front- and rear differentials; and finally, an optimal front/rear drive force distribution. From these results, graphical methods of the so-called dynamic square are connected to the classic g-g diagrams. Further the dynamic square is further developed to also show the influence of lef/right drive force distribution and the influence on the understeer of the vehicle