An energy-efficient torque distribution strategy for in-wheel-motored EVs based on model predictive control

In order to improve the energy efficiency (EE) for in-wheel-motored electric vehicles (IWM EVs), an optimal torque distribution algorithm is investigated based on model predictive control (MPC). Firstly, an optimisation structure is developed by considering energy efficiency characteristics of the motor and energy loss of tyre slip. To achieve the driving requirements, an upper layer controller determines a desired motor torque, considering the maximum capacity of the motor drive and regenerative brake. Then, an MPC-based torque distribution algorithm in lower layer deals with this energy efficiency optimisation problem with system dynamic and torque saturation constraints. Then to obtain the optimal motor torques fast, an efficient solution approach is given by combining constraint conversion and numerical methods. Finally, simulation results in different driving cycles indicate that overall energy efficiency and computational efficiency of vehicle can be improved. Also, the real-time control performance is guaranteed in the hardware-in-the-loop (HiL) simulation.