Integrated control of AFS and DYC for in-wheel-motor electric vehicles based on operation region division

Abstract

The integrated chassis control system can improve vehicle handling and stability effectively. This paper proposes an integrated control system based on operation region division of active front steering (AFS) and direct yaw moment control (DYC) for in-wheel-motor electric vehicles. The control system adopts a two-layer hierarchical control structure. The decision layer employs a modified sliding mode controller to calculate the required corrective yaw moment, and determines operating regions of the two subsystems based on the driving conditions (road adhesion coefficient, tyre load and wheel slip ratio). The execution layer generates the corrective steer angle and the driving/braking torques for the AFS and DYC subsystems respectively. Simulation results show that on the high-adhesion-coefficient road, the integrated control system appropriately adopts subsystems to improve handling, while attenuating the workload of barking system; on the slippery road, the integrated control system maintains vehicle stability and provides control performance superior to those resulting from the single systems.