Basis of vehicle dynamics - Stationary state, stability and transitory regime of yawing/drifting and rolling movements

In the first part of [AF 5 100] , we presented the four-degree-of-freedom model of the unguided terrestrial motor vehicle. In order to obtain the equations of motion, it was necessary to express the torsor of the external actions in terms of the kinematic parameters. This required a fairly detailed study of the behavior of the tire and the actions of the air on the vehicle. This system of differential equations governing motion was simplified in order to obtain two decoupled motion systems: a "yaw-drift" motion (three degrees of freedom) and a roll motion (one degree of freedom).

In the first two sections of the second part, we use the equations of motion for yaw-drift motion to study steady-state cornering motion and its stability under disturbance. In the next section, we continue by applying this approach to roll motion, and also look at load transfer. The fourth section is devoted to the notion of roll axis and the calculation of stiffness and anti-roll damping. We end with a more forward-looking section, highlighting the links between automatic control and multi-body system dynamics applied to vehicle dynamics, through the notion of "global chassis control".