A Vehicle Stability Control Criterion Based on Time Domain Disparity of Stability Variation Between Dynamic Differential Systems and Actual Vehicle

Abstract:

A complementary criterion for vehicle electronic stability control system (ESC) was proposed for qualitative estimation of the rear axle sliding conditions which might appear in vehicle planar motion. Taking into consideration the comprehensive effect of tangential force and axle load transfer on tire cornering characteristics, the stability criteria of 2DOF lateral dynamic differential systems and 3DOF systems with longitudinal acceleration were studied. By introducing the vehicle transient stability analysis approach, the quantized disparity between the stability variation of dynamic differential systems and that of the actual vehicle was obtained in time domain. Based on the lag effect, an anticipatory stability control solution was developed, which took the system equilibriums properties of the nonlinear reference model as the criterion. Under certain conditions which considering longitudinal dynamics, the stability boundary held by the maximum of yaw rate was close to actual stability variation of the vehicle. Thus, the response time of ESC system is limited. With the anticipatory criterion, ESC could predict vehicle status earlier.

Key words:stability of vehicle planar motion; stability criteria; time domain disparity; anticipatory control; transient stability analysis