Abstract
The reason of oscillating motion in steering of an automated driving bus at middle speed range is revealed and feedback control with six variables, including front tire angle, is proposed to damp the oscillation. Real-time kinematic GNSS with centimeter accuracy is used for selflocalization and the angle of the steering wheel is controlled by a motor equipped on the steering shaft. Root locus method considering the relation between lateral error and feedback gains indicates damping of the motion of the vehicle become smaller at middle speed range than at low speed range. The numerical simulation and experimental results show the six state variables feedback control has an advantage in obtaining high damping ratio with avoiding the vehicle leaving the travelling lane under the influence of the lateral wind and the transverse gradient.
