On a reduced-order two-track car model including longitudinal and lateral load transfer

In this paper we propose a novel reduced-order car model that captures some key features for aggressive maneuvering of complex car vehicles. The proposed model, called RigidCar, consists of a rigid body interacting with the ground at four contact points (two-track car) and including tire models and load transfer. The model does not include suspension models, thus keeping a reasonable level of complexity. Load transfer (both longitudinal and lateral) is taken into account by explicitly imposing the holonomic constraints and computing the reaction forces of the ground at the four contact points. Since the vehicle interacts with the ground at four contact points, it results to be a hyper-static structure so that reaction forces are not uniquely determined. We use the Principle of Least Work to get a compatibility equation and thus resolving the indeterminateness. We provide numerical computations validating the proposed model with respect to a multi-body virtual prototype on an aggressive ISO lane-change maneuver.