Abstract
This paper focuses on vehicle instability that is caused by driver's excessive steering on a slippery road. Then we confirm that driver's excessive steering gain worsen the stability of vehicle using model analysis which contains driver model and single track model. Standing of the result, we construct a vehicle stability control algorithm using electric power steering system (EPS) and active front steering system (AFS). It is well known that maximum self-aligning torque occurs before maximum cornering force is reached. Our proposed algorithm estimates self-aligning torque from the EPS signals, and AFS controls the overall steering gear ratio large when self-aligning torque is saturated. The results of simulations and actual vehicle tests show the effect of the control in improving vehicle stability.
