The objective of this study is to develop the control logic of the four wheel steering (4WS) and Integrated control of 4WS and Direct yaw moment control (DYC) in order to improve handling characteristics. The zero body side slip is their control target which is examined through the experimental method using the driving simulator. The developed logic are Acceleration feedback controlled 4WS(AF4WS), 4WS using Time delay control (TDC4WS), and Integrated control of 4WS and DYC (IC). The AF4WS logic does use the time derivatives of the vehicle states such as body side slip velocity and yaw rate as control variables which is available in a reasonable cost using the rate gyros, accelerometers, and vehicle speed sensor. The body side slip velocity can be minimized without any body side slip sensor and state observer. TDC4WS logic is designed to follow the yaw reference model which is pre-designed to reduce body side slip velocity. It shows the robustness against to the external disturbances only using the yaw rate sensor and acceleration sensors. Also the IC can be used to control both the side slip velocity and yaw rate with prescribed reference model because the logic uses two control actuators. The simulation is performed by DADS 16 DOF vehicle model successfully, so that applying the feedback control logic derived from 2 DOF model to higher order system is verified.
