Design And Reliability Research Of Electric Control System For Pure Electric Vehicle

With the increasing tension of limited oil and gas resources such as petroleum,the development of electric vehicles has played a huge positive role in improving the living environment.As one of the main directions of the development of electric vehicles,pure electric vehicles replace oil and gas drive with pure electric power,which has the characteristics of no exhaust,low noise and environment friendliness,and has become an important research content of the new energy industry.As the most critical subsystem of pure electric vehicle,the whole vehicle electronic control system plays a vital role in energy distribution,power drive,behavior management,safety and reliability,and driver's operation experience.Therefore,the reliability design of the whole vehicle electronic control system is of great significance to the research of pure electric vehicle.Based on the pure electric vehicle development project of a company in Liuzhou,this paper adopted the body structure of a passenger car,studied the structure and control strategy of the vehicle electronic control system,and achieved the reliability design of the vehicle electronic control system.The main contents are as follows:Firstly,the research background was described,and the research status of pure electric vehicle and vehicle electronic control system at home and abroad was analyzed.Then,the basic structure of pure electric vehicle was studied,and the overall design principles and schemes of the whole vehicle electronic control system were formulated based on the principle of pure electric vehicle and its whole vehicle electronic control system.The key contents of the whole vehicle control system structure and the whole vehicle control strategy were analyzed,and the design scheme of the whole vehicle control system with VCU as the main core was determined.Secondly,according to the differences between the structure characteristics and driving conditions of pure electric vehicles,this paper summarizes the working characteristics of vehicle behavior mode and transfer,and designs the on-off switch system,high-low voltage battery management and electric accessory system in vehicle control strategy.The reliability of VCU fault handling mechanism is analyzed by FTA fault tree,and the reliability scheme of accelerator pedal is studied.The VCUcommunication network and SAE J1939 communication protocol are realized.Subsequently,according to the characteristics of the project and the control strategy,this paper focuses on the completion of the high and low voltage on-off circuit,the electric accessory circuit and its related micro processing chip selection,VCU peripheral circuit,and analyzes and improves the reliability content.Then on the basis of it,the related VCU bottom driver module and upper main program module are compiled,and the corresponding function layer and vehicle control strategy software design and integration are completed in Freescale CodeWarrior.Finally,the VCU monomer and the vehicle electronic control system are tested.The former includes function test,interference test,and the working characteristics and reliability of VCU are tested.Then,the prototype car is installed and debugged to optimize the parameters of the vehicle's electronic control system,and verify the performance of the vehicle system in different working environments.Combined with the design scheme,the working effect of the vehicle's electronic control system is verified.