This article deals with two theoretical analyses for optimum control of a driver /four- wheel- steered- vehicle system and their evaluation by computer simulations and experiments with a driving simulator.Conventional methods of stability and controlability analysis for a front- wheel- steered- vehicle are not always applicable to the four- wheel- steered- vehicle, because lateral and yaw motions of the latter can be controlled independently to some extent. Therefore, a closed- loop system including the vehicle and a driver is treated in the present analyses.
Abstract