Research On Control Strategy Of Electronic Park Brake For In-wheel Motor

With the increase in the degree of electrification of automobiles and the dependence of autonomous driving on electrification,the overall integration of the chassis of electric vehicle vehicles has been improved,and the braking safety performance of electric vehicles has been improved.This paper proposes a method of applying vehicle wheel hub motor to directly apply service brake and parking brake.First: This paper analyzes the braking principle of the vehicle,designs a road surface adhesion coefficient estimation method based on Kalman filtering,and thus obtains the vehicle braking slip rate control model.Secondly: According to the vehicle’s active safety requirements,three different control strategies for ramp starting,emergency braking,and automatic parking are designed respectively for three common operating conditions.The ramp starting control strategy corresponds to The auxiliary driving conditions of the vehicle,using the slope of the vehicle as the compensation condition,the corresponding compensation torque is output by the wheel motor to assist the driver to start smoothly;emergency braking corresponds to the service brake of the vehicle,and the wheel is based on the logic threshold control idea.The torque output of the motor during emergency braking is controlled to meet the safety requirements of the vehicle’s anti-lock control;automatic parking corresponds to the parking brake conditions of the vehicle.Based on the safety performance requirements of electronic parking,the driver is assisted in Automatic parking during dangerous operation.Finally: In Matlab/Simulink,the corresponding models of three different function realization logics are established to verify the feasibility and effectiveness of the optimization model,and the established Simulink model is converted into corresponding C code for engineering implementation in the matching hardware system In the actual vehicle test,the feasibility of the wheeled motor for electronic parking function was verified.In the test process,the signals of the vehicle test process are collected by the vehicle CAN bus signal acquisition device such as Vector.By analyzing the corresponding signals,the designed functional logic can be further optimized and the function debugging can be performed according to the corresponding hardware.