Technical Paper
On the Investigation of Car Steady-State Cornering Equilibria and Drifting
2024-04-09
2024-01-2764
This paper proposes a thorough investigation of drifting equilibria for a Formula SAE car. When discussing drifting, it is commonly assumed that yaw rate and steering angle have opposite sign, i.e. the driver is countersteering. Yet, under certain circumstances, another unstable equilibrium condition may occur, referred to as semi-drift in this work. An inverse model - based on a nonlinear single track - is proposed to compute the required driver inputs – longitudinal speed, steering angle and rear traction force - to perform a steady-state turn for a given radius of cornering and sideslip angle. Such steady-state (equilibrium) sets are then categorized: drift, semi-drift or normal turn. The mathematical meaning of the equilibria is explored by linearizing the system and analyzing eigenvalues and eigenvectors of the resulting state matrices.