ABSTRACT
In this paper, a quasi-steady-state method is applied to four-wheel-drive (4WD) vehicles to study on the effects of traction force distribution controls on the vehicle turning behavior during acceleration and power off braking. Solving the quasi-steady-state equilibrium equations, the steering wheel angle to turn with a certain turning radius of curvature with respect to lateral acceleration is obtained for various longitudinal acceleration to describe understeer/oversteer(u.s./o.s.) characteristics in acceleration and power off braking in a turn having the same implication as in a steady state turning. The optimum traction force distribution control having relation to tire vertical loads with additional rear wheel steer to attain vehicle turning behavior which are insensitive to acceleration and power off braking as well as to get high acceleration capabilities is investigated.
