Research On Distributed Rear Drive Formula Student Electric Car Control System

As a platform for students’ self creation and communication,the Formula Student Electric China(FSEC)has provided fresh blood for the automobile industry and made students more fully understand electric vehicle manufacturing.The distributed drive electric vehicle directly installs the motor near the wheel,eliminates the energy loss between the differential and other components,and has the advantages of independent control of the torque of each driving wheel.Therefore,the handling and stability control of distributed drive electric vehicle can be easily realized.This research takes the pure electric dual motor distributed drive formula racing attacker-2020 of Zhejiang University of science and technology as the research object,in order to improve the stability and comprehensive dynamic performance as the goal,and make full use of the characteristics of distributed drive racing,that is,the torque of the driving wheel is independently controllable,to design a vehicle controller based on yaw rate,sideslip angle and slip rate of the driving wheel,Its handling stability is studied.According to the theoretical design parameters of the car,the parametric modeling software Car Sim is selected to establish the whole car model of the distributed driving equation car,which mainly includes the car body,power and transmission system,tire and suspension system,and then the Car Sim / Simulink co simulation platform is built to realize the simulation research of the distributed driving equation car.This paper expounds the influence of tire on vehicle stability;When the vehicle handling stability changes,the performance of yaw rate and mass center sideslip angle.The extended Kalman filter observer(EKF)based on linear two degree of freedom model is established to observe the actual vehicle state.Based on fuzzy control theory,a combined control mode of yaw rate and mass center sideslip angle is designed.In the upper layer of the controller,the fuzzy PI control method is used to control the yaw moment directly.The sideslip angle of the mass center is used as the reference value of the fuzzy control.The feedback control of the yaw rate makes it follow the target value automatically.The required yaw moment is calculated and distributed in a certain proportion.In the lower layer of the controller,an additional yaw moment control based on slip rate and vehicle speed is designed,and the yaw moment can be adjusted in the appropriate range of vehicle speed.In the built Car Sim / Simulink co-simulation platform,firstly,the simulation is carried out for the eight character detour and high-speed obstacle avoidance.In the eight character detour test,the actual value of the sideslip angle of the mass center is reduced by about 9%,the variation range of the yaw rate is increased by about 10%,in the highspeed obstacle avoidance test,the total time is reduced by 5%,and the variation range of the sideslip angle of the mass center is reduced by about 10%.Finally,in order to reflect the real state of the vehicle,a 1000 m track is designed and tested.The results show that the additional yaw moment distributed by the control system can achieve good real-time tracking of yaw rate,and the control algorithm can stabilize the sideslip angle of the center of mass,improve the dynamic performance of the vehicle,and achieve the control purpose of improving the stability of the car.The research provides control strategy and technical support for distributed independent drive car,and has certain reference significance for improving car performance.