Research On Dual Motor Drive System Of Formula Electric Racing Car And It’s Dynamic Control

Based on the application status of distributed drive technology for electric vehicles at home and abroad,this paper takes the dual-motor drive system in the college electric equation car competition as the research object,and through the joint simulation technology of Carsim and Simulink,the influence factors and rules of the torque distribution control algorithm and the traction control algorithm are analyzed,which can provide guidance for the anti-skid technology of rear-wheel drive pure electric car.The main contents of this paper include:(1)In order to evaluate and design pure electric equation racing car with rear wheel drive,a seven-degree-of-freedom non-linear model is established based on vehicle dynamics.The parameters of motor and transmission system are calculated and analyzed,the motor model and transmission ratio are determined,and the driving motor model is built in MATLAB/Simulink.Based on the magic formula,the accurate tire model is determined by fitting the tire test data,and the target values of tire slip rate and cornering angle in the control system are analyzed.The relationship between steering system angular transmission ratio and steering wheel angle and vehicle internal and external wheel angle is determined,and the steering system model is established.The parameters and grouping mode of power lithium battery are determined,the simulation battery model is built,and the mathematical model of vehicle and power transmission system is established.(2)The vehicle dynamics simulation model and Simulink vehicle simulation platform are established by Carsim software.The sensor input signals and their range required by the control system are determined,and the vehicle control strategy of the layered architecture is proposed.For the target of longitudinal and lateral stability of electric vehicle steering conditions,the torque distribution control strategy during steering is proposed.T he yaw rate of the vehicle is used as the control target,and the torque of the two driving wheels of the rear axle of the vehicle is used as the control variable.A torque distribution controller based on PI and LQR is designed.The deviation of the yaw rate of the vehicle and its reference value is taken as the control input.The additional yaw moment of the whole vehicle is used as the output to dynamically control the output torque of the drive wheel.Secondly,for the goal of electric vehicle racing in the longitudinal acceleration of linear acceleration conditions,taking into account the constraints of motor failure and road surface adhesion characteristics,the traction force control of the drive wheel based on the target slip ratio is established.Finally,the security protection control layer limits the output power of the drive system according to demand and monitors the battery power.(3)Based on the co-simulation verification platform,the simulation of the drive control system controller is completed,including the torque vector distribution control algorithm verification based on the PI control torque distribution controller and the LQR controlled yaw moment controller,and the traction control based on the target slip ratio.Verification,drive system security protection verification.The effectiveness and stability of the control strategy under different working conditions are verified,and the design goals and layout schemes of the dual motor drive system are proposed.