Research On Distributed Electric Vehicle Driving Force Distribution Control Strategy

Since the four driving wheels are independently controllable,distributed electric vehicles can realize vehicle safety and stability control,and have good development and application prospects.When the drive motor is running normally,the vehicle will still lose stability under different driving conditions and environments.When the driving motor fails,the driving stability and safety of the vehicle will be further damaged.Based on this,this article explores and studies the driving force distribution control under normal and faulty driving motors:Establish a two-degree-of-freedom reference model for vehicles to provide a basis for formulating allocation control strategies.According to the vehicle power performance index requirements,the in-wheel motor is matched with parameters.A simulation model of the drive motor was built using Matlab,and finally a distributed electric vehicle dynamics model was built in conjunction with Carsim.A driving force distribution control strategy is proposed for the normal operating conditions of the driving motor,and the relationship between the vehicle motion state and stability is analyzed,and the vehicle instability judgment method is established.This strategy uses sliding mode control theory to synthesize the influence of the yaw rate and the side slip angle of the center of mass on vehicle stability,and designs a lateral weighting controller;the total longitudinal force of the vehicle is obtained through PID control;Finally,the objective function and constraint conditions based on the maximum tire adhesion margin are constructed,and the solution is completed by quadratic programming.In view of the driving motor failure conditions,the impact of the driving motor failure on the stability and safety of the vehicle under different wheels,different speeds and different driving requirements is analyzed.Constructed a mathematical model of driving force distribution to maximize yaw stability and dynamics when the driving motor fails;When the drive motor is saturated due to its output capacity,a distribution controller that cooperates with the front wheel steering is designed to compensate for the yaw moment to complete the safe reconstruction.Combine Matlab/Simulink and Carsim to establish a simulation model for the distribution control of the drive motor under normal and fault conditions.Perform simulation verification at different driving speeds and different turning conditions when the four wheels are driving normally.When the drive motor fails,perform simulation tests at different vehicle speeds in straight and turning driving conditions and failures of different drive motors.The results show that the distribution control strategy proposed in this paper can improve the stability during normal driving and effectively reduce the yaw rate error caused by the failure of the drive motor,ensuring the safety,stability and dynamics of the vehicle.