Regenerative Braking with Direct Adhesion Control for Distributed Drive Electric Vehicles

Energy recovering for distributed drive electric vehicles (DDEVs) is challenging due to the coupling mechanism between safety, efficiency, and braking performance, especially on complex tire-road adhesion conditions. A new regenerative braking strategy using direct adhesion force control is proposed in this research, considering both the normal braking and the emergency braking on the unknown adhesion road. A fuzzy PI controller is adapted to track an estimated required adhesion force limited to the adhesion peak of an unknown road condition. Furthermore, a braking torque distribution scheme is formulated for DDEVs. A simulation was conducted in comparison with the PI and the MTTE control methods. Results show that the proposed scheme achieves a higher utilization rate of road adhesion and a higher braking energy recovery effect while functioning a more stable braking maneuver.