Recently, vibration control of a wheeled vehicle running over an irregular terrain, which is applied to an aspect of forest farmland and a stricken district etc. has been studied. In order to increase the mobility of the vehicle and the stability of circumstance sensor, it is very important to decrease the rolling and pitching vibration, which is caused by irregular terrain. This paper proposes a model to control the rolling and pitching vibration by using the relative displacement and then controlling the position of vehicle for a four-wheeled vehicle. On the other hand, about constitution of position system, the following four control methods are considered according to the extent of terrain information.
(1) Whole preview control method that uses present and future terrain information.
(2) Partial preview control method that uses present (all wheels') and future (only hind wheels') terrain information.
(3) Feedforward compensation control method that only uses present terrain information.
(4) Feedback control method that doesn't use any terrain information.
According to theoretical computation for performance index and numerical simulation, the effect of position control can be further improved by utilization of terrain information actively.