Torque optimization control for electric vehicles with four in-wheel motors equipped with regenerative braking system

This paper presents a novel braking torque distribution strategy for electric vehicles with four in-wheel motors equipped with the regenerative braking system. Safety and regeneration efficiency are the two major themes in the design of a regenerative braking system. Based on model predictive control (MPC) theory, the issues of multiple objectives and constraints of the regenerative braking system is well addressed. This proposed torque distribution controller can maximize the regeneration efficiency by determining the hydraulic braking torque and motor braking torque, which subject to the actuator constraints. Total braking torque of the four wheels tracks the braking requirement. Furthermore, in the case of ensuring brake safety, the braking torque of front and rear wheels are optimized to improve the possibility of energy recovery. The simulations have been conducted in Simulink environment based on an electric vehicle model established in AMESim software to verify the advantage of the proposed model predictive controller. In addition, the real-time test also demonstrates the effectiveness of the presented optimal control strategy.