Four-wheel Drive Electric Vehicles Torque Distribution Strategy Based On Objective Optimization

As an important research direction of electric vehicles,the four-wheel independent drive electric vehicles has more obvious advantages at the vehicle motion control and optimize the allocation of driving force.This paper carried out researchon four-wheel independent drive electric vehicle models and vehicle electronic differential system,and designed the torque distribution strategy in the electronic differential system.1. this paper had a reseach on the vehicle structure and electric differentialsystem of four-wheel independent driving electric vehicles,established electric vehicle control logic block diagram,and analyzed the main functions of driving system,power system and control system in electric vehicle.2. In order to explore the characteristics of the vehicle kinematics,this papercarried out research on the vehicle model of electric vehicles,and established four-wheel independent drive electric vehicle model based on the traditional car model in DYNAware.then,verified this model at acceleration and deceleration conditions, indicating that the model can through the driver’s accelerator pedal,brake pedal and steering wheel angel signal accurately reflects the operation of the vehicle path and status.3. Electronic differential torque distribution system research and design,consider the car in the case of motor failure,as well as in hard acceleration,acceleration,deceleration, rapid deceleration operation conditions, this paper based on stability the target objective optimization wheel independent drive torque distribution strategy,and the objective optimization problem is transformed for the extremal problem was solved.In this paper,automotive hard acceleration,sharp turns, slow turn normal condition and three different wheel hub motor failure conditions of the simulation,toverify the effectiveness of this paper,the design of the four-wheel independent drive electric vehicles torque distribution strategy.Experimental results show that the torque distribution algorithm,in normal operating conditions and the hub motor fault conditions,is possible to better track the trajectory desired by the driver, at the control performance is far superior to the average allocation algorithm and asimple drive torque control algorithm control effect. It is evident that the torquedistribution strategy can improve vehicle stability and trouble-free operation.