In this paper, a quasi- steady- state method is applied to four- wheel- drive (fwd) vehicles to study the effects of traction force distribution controls on the vehicle turning behaviour during acceleration and Power off braking. Using quasi- steady- state equilibrium equations, the steering wheel angle to turn with a certain turning radius of curvature with respect to lateral acceleration is calculated for various longitudinal accelerations, in order 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. This article investigates the optimum traction force distribution control in relation to tyre vertical loads with additional rear wheel steer, in order to attain vehicle turning characteristics which are insensitive both to acceleration and power off braking, and to attain high acceleration capabilities is investigated.
Abstract