Vehicle Cornering Characteristics in Acceleration and Braking through Attitude Control of Front and Rear Tires

摘要

A new active control method for the attitude angles of wheels is proposed to improve the the maneuverability and stability of automobiles. From theoretical analysis and computer simulation, it is clarified that this control yields satisfactory vehicle cornering performances during steering, acceleration and braking. The dynamics of lateral movement and yawing of the vehicle as a result of tire attitude control are investigated using a quasi-steady-state analysis model for the case of tractive or braking force. An extended stability factor related to the characteristics of toe and camber angles of wheels is defined, which is applicable to circular turnings with lateral and longitudinal accelerations. Effects of control are analyzed using this factor. Furthermore, a modified control method is proposed, which makes it possible not only to improve vehicle dynamics but also to decrease actuating values of attitude angles in actual driving.