Study On Drivability Of Pure Electric Vehicle Based On Traffic Scenario

Due to the energy consumption and environmental pollution caused by fossil energy,the unique advantages of new energy vehicles have attracted a lot of attention.Because of the advantages of energy saving,environmental protection and low noise,pure electric vehicles are more and more favored by automobile enterprises.Different from traditional fuel vehicles,pure electric vehicles due to the dynamic performance of the motor power supply,start more sudden than a conventional car,the dynamic properties of the rating is urgent to accelerate slightly insufficient,at the same time because of the pure electric vehicles in the traditional fuel vehicle braking system joined the motor regenerative braking system,the response is slower than the response of the motor of the hydraulic system,two kinds of brake mode switch to each other,Must cause the power transmission system torque fluctuation,affect the vehicle driving performance and ride comfort.In order to improve the vehicle driveability and ride comfort.This paper takes the power system of pure electric vehicle as the research object and studies the drivability control strategy of pure electric vehicle based on traffic scenarios.The main research contents are as follows:(1)The structure of the research object of this paper is analyzed,and the motor model,battery model,AMT model,vehicle longitudinal dynamics model and braking force distribution model are respectively established in Simulink.(2)The structure and drivability of the pure electric system studied in this paper are analyzed,which are divided into start smoothness,rapid acceleration response,shift smoothness and braking mode switching smoothness.And focus on the dynamics analysis of the start,rapid acceleration,AMT shift process and determine the driving performance of pure electric system key parameters and evaluation criteria.(3)To study the upper and lower control strategies for the drivability of pure electric vehicles based on traffic scenarios.Mainly include:1)To construct the traffic scene,the upper control strategy is to control the speed of the controlled vehicle for the purpose of stable following,and determine the expected speed of the main vehicle when it disembarkates in the traffic scene.The main purpose is to enable the pure electric vehicle to have the ability to drive safely and efficiently in this scene.2)Compare the driving performance in the process of motion state switching involved in the constructed traffic scene with that of pure electric vehicles without strategy.Finally,the real-time torque coordination algorithm is combined to formulate the driving performance including starting,rapid acceleration,The drivability control algorithm is based on the motor torque distribution algorithm in the shifting process and the coordination algorithm of the electric mechanism torque and hydraulic brake torque in the braking mode switching process,in which the vehicle driving motor torque distribution algorithm and the braking process torque coordination algorithm constitute the lower control strategy.(4)Co-simulation analysis based on Prescan and Simulink drivability control strategy.The drivability control strategy is simulated and verified in real time in Pre Scan.Compared with the traditional control strategy,the results show that the drivability control strategy developed in this paper can correctly respond to the driver’s speed demand,reduce the impact during the driving process of pure electric vehicle,and improve the drivability.