Research On Torque Coordination Distribution Of In-Wheel Motor For Electric Vehicle

Because of having the advantage of clean and no exhaust gas,Electric vehicle will replace the fuel vehicles at future gradually,to improve the air pollution problem.The increase of car ownership have been making the traffic conditions more complicated and affecting the safety of the vehicle.In case of emergency,the driver press on the throttle mistakenly and change steering wheel quickly due to excessive tension,this way can easily lead to lateral instability of vehicle.So,The study of the lateral stability control of the vehicle is great significance for improving the stability of the vehicle.This paper adopts the coordination distribution of the torque of in-wheel motor to realize the lateral stability control of the vehicle based on the advantages of fast response speed and non-disturbance of torque control of in-wheel motor.In order to achieve torque optimal distributed and driving stability for vehicle,a method of coordinating torque distribution for in-wheel motors of electric vehicles is designed based on the driver intention identification,lateral stability control,optimal torque distribution control,slip rate control,and motor control.The main content are as follows:(1)The vehicle model is built by the Carsim software based on known vehicle data,and the motor model is built by the MATLAB/ Simulink and the both controller model as a platform for simulation and verification of various control strategies designed in the paper;(2)The driver intent identification models is built by using neural networks,the model have two inputs as opening and opening rate as the output of electronic pedal,the desire torque coefficient is obtained through the models and distributed to each in-wheel motor in real time;(3)The required ideal yaw torque for guaranteeing vehicle stability is calculated by the LQR strategy based on the linear two degrees of freedom model of vehicle,and the torque is distributed to in-wheel motor according to the designed torque coordination distribution strategy to ensure the stability of the vehicle;(4)The anti-skid function for wheel is achieved by the optimal slip ratio control to compensate longitudinal moment of in-wheel motor in the progress of yaw moment distribution,and the motor is controlled by fuzzy-sliding mode control strategy according to the degree of the required torque;The strategy proposed in this paper are tested by theunite simulation plant: the signal of the actual pedal is used as the real-time input of the test platform to verify the effectiveness of the improved torque distribution strategy,the feasibility of the shaking control for in-wheel motor by the fuzzy-sliding mode control strategy,and achieving the reduce shaking control of the motor under the condition of ensuring the lateral stability of the vehicle under the extreme conditions.