Enhancement of Handling and Cornering Capability for Individual Wheel Braking Actuated Vehicle Dynamics

In this paper, active safety enhancement for individual wheel braking actuated vehicle dynamics is presented. The nonlinear tire characteristics play an important role during manoeuvering tasks since tire forces may be saturated when the tire slip angle exceeds some a priori unknown slip value. Saturated forces, especially in the lateral direction, may result in an increase on the vehicle side slip angle and manoeuvering task may not be accomplished safely while the vehicle is drifting out of its trajectory. Regulation of tire forces may be very difficult at controller development stage due to modeling and analytical complexities and due to the presence of many unknown factors such as the road-tire friction coefficient. This paper proposes a controller methodology that may prevent the saturation of the lateral tire forces by regulating the individually actuated wheel brake actuators. The phenomenon of tire force saturation in the lateral direction is detected by comparing the individually estimated lateral tire force with its linear form simultaneously, and regulating the decentralized individual hydraulic wheel brakes to reduce the tire slip angles. Simulation results are illustrated to show the effectiveness of the proposed approach.