Abstract:

For the high energy consumption problem caused by the large torque fluctuations of in-wheel motor-driven vehicles on uneven roads and frequent shifting of vehicles， in this paper a method for energy consumption optimization of in-wheel motor-driven vehicles considering torque fluctuations is proposed. Firstly， based on the longitudinal drive dynamics equation of electric vehicles and the CarSim vehicle dynamics model， the motor energy consumption model， tire slip energy consumption model， and yaw torque tracking error model are established as the upper control target， and the in-wheel motor dynamics model considering road surface excitation is established as the lower control target. Secondly， taking the upper-level control target as the objective function of the torque optimization of the in-wheel motor vehicle， the motor torque and speed energy limit as the inequality constraints， and the fuzzy control method for objective function weight distribution， the upper-level torque optimization model is established based on NSGAⅡ. At the same time， the lower-level in-wheel motor vector control model of torque overshoot and delay caused by road surface excitation is established based on the sliding mode anti-disturbance observer. Finally， the joint simulation of Simulink and CarSim of a four-wheel in-wheel motor-driven car is carried out， and the changes of the front and rear axle wheel torque， total energy consumption of the car， and the SOC of the car battery under different optimization methods are analyzed under WLTC operating conditions and CLTC-P operating conditions. The in-wheel motor bench test shows that the energy consumption optimization method of in-wheel motor-driven vehicles considering torque fluctuations can effectively reduce energy consumption under WLTC and CLTC-P operating conditions.

Key words: in-wheel motor drive automobiles, torque fluctuation, NSGAII, SMADO, energy consumption optimization