Research On Stability Control Method Of Four-wheel-drive Electric Car

With the global environmental pollution and increasingly serious greenhouse effect,new energy vehicles begin to enter people's vision.With the development of the automobile industry,more and more attention has been paid to electric vehicles in the world.Many automobile manufacturers and research institutes have begun to conduct in-depth research on electric vehicles.This paper takes the four-wheel independent drive electric car as the research object,through the analysis of the motor drive control and the whole vehicle model of the pure electric car,puts forward the electronic differential steering control strategy of the pure electric car based on the four wheel hub motor,and analyzes the driving safety and handling stability of the whole vehicle.Finally,through the simulation of the whole vehicle,it verifies that the proposed differential control strategy has Effectiveness.First of all,by comparing the performances of many kinds of motors and the needs of the practical research of the loading motor,the permanent magnet synchronous motor with better comprehensive performance is used as the wheel hub drive motor of the four-wheel electric racing car.By analyzing the mathematical model of the motor and the principle of the direct torque control,the simulation model of the direct torque control is built in Matlab / Simulink,and the simulation waveform of the current and speed is obtained The results show that the torque response of DTC system is faster under no-load and sudden load.Then,aiming at the four-wheel independent drive electric racing car that this paper is going to study,the whole vehicle model is built,including the seven degree of freedom model and the tire model.At the same time,the two degree of freedom model is built for the ideal situation,and the corresponding model is built by using Matlab / Simulink.Secondly,a differential control method based on Ackermann steering model is proposed.At the same time,in order to solve the problem that the traditional PID control can't restrain the speed overshoot,an optimal differential control method of ADRC is proposed,which can greatly reduce the number of setting parameters.And in Matlab /Simulink,the differential control model of electric car is built.Through the comparative analysis of the simulation results,it is verified that the optimal ADRC algorithm is effective in the speed control based differential control,and more adaptive in the uncertain factors such as load disturbance.Finally,by analyzing the stability factors of the vehicle,the stability control strategy of the electric racing car is formulated;at the same time,the model of the whole vehicle is established by using Matlab / Simulink,and on this basis,the simulation experiments of sine angle input condition and step angle input condition are carried out.The simulation results show that the operation process of the whole vehicle is always under the ideal value,and the operation track is also under the expected condition It is verified that the proposed electronic differential method can effectively guarantee the stable operation of the whole vehicle.