Integrated vehicle dynamics control of rear steering angle and driving/braking torque to improve vehicle handling and stability of a small four in-wheel-motors vehicle

Concerns about limited petroleum supplies and global warming drive the demand of fuel-efficient vehicles. Thus, in recent years, interest in development of small electric vehicles for 1 or 2 passengers is getting stronger than ever. Small electric vehicles are more vulnerable to vehicle handling and stability under emergency maneuvering conditions such as side wind [1] because small electric vehicles, which is compact size and lightweight, respond to steering induced maneuvers more quickly with greater amplitude. Although the authors have proposed the integrated vehicle dynamics control of front steering angle and driving/braking torque to improve the vehicle handling and stability of small electric vehicles [2], the interference between the front steering angle control and the steering of the driver in the lower frequency range than 1 Hz has been pointed out as a problem [3]. This paper describe design of the integrated vehicle dynamics control of rear steering angle and driving/braking torque to reduce the driver´s steering load in terms of vehicle handling and stability of a small electric vehicle with four in-wheel-motors (small IWM vehicle).