Braking Torque Distribution Reconfiguration Strategy of Vehicle With Faults of In-Wheel Motor Drive System

In this paper, pertinent to the fault states of motor drive system, a braking torque distribution reconfiguration strategy of the vehicle with faults of in-wheel motor drive system is proposed to improve vehicle comprehensive braking performance. Firstly, based on the detected phase current and position signals of switched reluctance motor, a novel fault detection method is proposed to accurately detect open-circuit and short-circuit faults of SRM drive system. Next, a braking force distribution strategy is proposed and applied to ensure the vehicle braking performance. Then, considering vehicle endurance mileage, braking stability, and braking safety, a new hierarchical control structure is designed, which includes upper-level controller and lower-level controller. In the upper-level controller, a direct yaw torque control method is proposed to improve vehicle stability. In the lower-level controller, an electrical braking force adjustment strategy based on multi-objective optimization is proposed considering regenerative braking energy, vehicle yaw rate, and braking distance, and the adjustment coefficients of electrical braking force are optimized via genetic algorithm. The weight factors of the proposed strategy are defined by analytic hierarchy process. Finally, a hardware in the loop is carried out under the selected braking conditions, which indicates the proposed strategy has better braking performance.