Electric rear axle torque vectoring for combined yaw stability and velocity control near the limit of handling

In this paper we propose a control architecture to stabilize a vehicle during cornering near the limit of lateral acceleration using the rear axle electric torque vectoring configuration of a hybrid vehicle. A vehicle model incorporating nonlinear tyre characteristics and coupling of tyre forces along longitudinal and lateral directions is used to calculate reference steady-state cornering conditions, as well as to design a linear controller with wheel slip ratio inputs. A backstepping controller then provides the necessary motor torques to achieve the wheel slip ratio requested by the linear controller. The controller provides stability of the lateral vehicle dynamics and regulates the longitudinal velocity to ensure feasibility of the reference trajectory.