Research On Vehicle Control Strategy Of Distributed Drive Electric Vehicle

With the increasing attention of the country and society to the energy crisis and environmental pollution problems,petrochemical energy-powered vehicles will gradually be eliminated.Pure electric vehicles with high efficiency,low energy consumption,zero pollutant emissions and other advantages have been greatly development.At present,pure electric vehicles generally adopt a single motor driving method,which has problems such as insufficient output power and insufficient climbing ability.In this paper,the distributed drive(four-wheel drive)electric vehicle driven by in-wheel motor is taken as the research object,and the key technologies such as yaw moment control,road adhesion coefficient estimation,driver intention recognition,torque distribution and slip rate control are taken as the main research contents.The research on torque distribution of yaw torque control combined with driving intention recognition is an innovation and an important research content.The driving control strategy of distributed pure electric vehicle is simulated and verified by using MATLAB and Carsim.In order to better to realize the torque distribution of distributed electric vehicles and ensure the stability of vehicles,a hierarchical control strategy is proposed to this paper.The strategy is divided into three layers.(1)Driving intention identification and torque calculation layer,which is mainly to identify the driving intention,the estimation of the road surface adhesion coefficient,the calculation of the yaw moment and the calculation of the total demand torque.(2)Torque distribution layer,which mainly distributes the wheels torque according to the driving intention and yaw moment obtained from the upper layer.(3)Based on the logic threshold method,the slip rated control layer mainly calculates the slip ratio of the current wheel,adjusts the driving torque of the wheel,and ensures that the wheel slip ratio does not exceed the optimal slip ratio.Then,use Matlab and Carsim to build a joint simulation model,in which the vehicle model is built in Carsim,and the control strategy,motor and battery model are established in Matlab.In the joint simulation platform,driving intention module,road adhesion coefficient estimation module,torque allocation strategy module and anti-skid module are tested respectively.The results show the effectiveness and accuracy of each sub-module.Then,the overall control strategy is verified.The simulation results show the effectiveness and accuracy of the hierarchical control strategy proposed in this paper.