Influence of the Speed-Dependent Tire-Road Friction on the Car Drifting Dynamics

The Force and Moment properties of the tire under large slip maneuvers have speed-dependent feature. The tire force model considering such feature is introduced to the car drifting model. The influence of it to the drifting dynamics is analyzed in detail from the aspects of drift equilibria, phase portrait and control. The analysis of drift equilibria shows that the front lateral force has a large level of unsaturation as counter-steer angle increases due to the decrease of the rear friction coefficient. The analysis of phase portrait shows that the steering characteristics of system, the number of equilibria and the unstable area in the phase plane vary significantly at larger steer angles. The simulation results show that the system considering such feature is easy to enter the drift state and has relatively better anti-interference ability especially in the process of exiting drift.