Research On Lateral Stability Control Strategy Of Distributed Drive Electric Vehicle

Traditional vehicles have caused serious social problems,such as energy shortage and environmental pollution.It is an era trend to develop energy-saving,safe and environmentally-friendly electric vehicles.Distributed-drive electric vehicle is an important form of electric vehicle development.The torque of each wheel is independently controllable,which provides more implementation and research potential for vehicle stability control.This paper studies the lateral stability control of distributed drive electric vehicles,including four aspects: the establishment of vehicle dynamics model,the design of the centroid side yaw estimator,the design of the additional yaw moment decision module,and the design of the torque distribution module.The distributed drive electric vehicle model is built in Matlab/Simulink and CarSim software,and the simulation is carried out in the steering wheel angle step input conditions and double-shift conditions to verify the accuracy of the vehicle model.The sideslip angle is an important parameter for vehicle stability control.Real time and online to know the sideslip angle of vehicle stability control is very important,but it is difficult to obtain by measurement method directly.In this paper,the sideslip angle is estimated based on Extended Kalman Filter algorithm.Analyze the cause of vehicle instability and select the state parameters that can characterize the stability of the vehicle.On this basis,the ideal value of the two-degree-offreedom vehicle model are taken as the control objective,the top controller is designed to calculate the additional yaw moment to maintain the stability of the vehicle.The lower yaw moment is designed to study the two torque distribution methods.One is the hydraulic force difference control method,which identify the vehicle's motion state and select the wheel that needs braking control and use the single-wheel brake to realize the distribution of the yaw stability torque.the method is basically the same as the torque distribution method of the traditional car.The other is the yaw moment distribution based on the motor characteristics,and the motor output torque of the four wheels is distributed by the quadratic programming method with the minimum tire utilization rate as the design goal.Under the double-shifting condition,the lateral stability control strategy is verified.The results show that lateral stability controller designed of the distributed drive electric vehicle in this paper can ensure the vehicle follow the ideal value to ensure the lateral stability of the vehicle under severe driving conditions.