Hierarchical control for distributed drive electric vehicles based on four-wheel steering

To improve the flexibility of electric vehicles at low speed, handling performance and yaw stability at high speed, and make full utilisation of the advantages of four-wheel steering. In this paper, a hierarchical control strategy for handling stability based on variable wheelbase reference model is presented. In the upper controller, a stability judgement controller is established to coordinate operation of the four-wheel independent steering system and direct yaw moment control system under various driving conditions. In the low layer controller, an optimal torque allocation strategy is designed to reasonably distribute the braking/driving torque. The results show that the proposed control strategy can improve the flexibility of electric vehicle in a small turning radius, and the yaw stability and handling performance under the extreme conditions. Copyright © 2023 Inderscience Enterprises Ltd.