Research On Electronic Differential Control Strategy Of Small Car Based On Ackermann Model

Electronic differential(EDS)is an electronic device that can control the wheel speed difference of electric vehicles(EVs),and its control strategy principle is to distribute the wheel driving force by controlling the wheel speed difference.In order to achieve precise distribution of driving force,a controller that can accurately detect the speed of the vehicle and correct it in real time is required.EDS(Electronic Differential System,electronic differential lock)by the electronic control unit(ECU)to monitor the wheel speed,when detecting the two wheel speed is different,the ECU adjusts the wheel drive force distribution,specifically manifested as improving the low-speed wheel driving force,reducing the high-speed wheel driving force to reduce the vehicle tightening and mistracking,to ensure driving reliability and safety.In view of this,this paper will explain the control strategy principle of electronic differential,and simulate the electronic differential control strategy of electric vehicles based on some control algorithms commonly used in automotive engineering.In order to study the main performance of automobiles,the nonlinear 7-DOFs(Degree of Freedom,DOF)vehicle dynamics model is first established,the permanent magnet brushless DC motor model is constructed,and the four-wheel independent drive electric vehicle joint simulation model is established based on Carsim software and Matlab/Simulink software,which lays a theoretical foundation for the design,analysis and verification of electronic differential control strategies in the later stage.Secondly,the improved PSO optimization EKF algorithm is used to estimate the key vehicle state parameters that are not suitable for direct measurement,such as centroid declination angle and yaw angle speed,which is conducive to the real-time feedback adjustment of the later electronic differential control strategy.Then,the electronic differential control strategy is designed based on the Akaman steering model,and the sliding surface is designed with the minimum hemp angle error of the lateral swing speed and centroid side declination in the upper layer to maintain the stability of the vehicle.The lower layer distributes the driving torque according to the load of each wheel,tracks and controls the wheel speed,and assists the logic gate circuit to control the slip rate.Finally,the experimental platform of small four-wheel independent drive electric vehicle with electronic differential control strategy is built,which verifies the correctness of the above control strategy and proves the feasibility and effectiveness of electronic differential control of four-wheel independent drive electric vehicle.