Design Of Vehicle Control Unit And Research On Driving Control Strategy For The Pure Electric Minivan

As the most common means of transportation,fuel vehicle,its energy consumption and exhaust emissions have become the core factors of the global energy crisis and climate warming.The development and prosperity of pure electric vehicles are the major changes in the global energy crisis and the solution of climate warming.Pure electric minivan,as a kind of pure electric vehicle,plays an important role in suburban and urban transportation.It is an important transportation tool to solve the "last kilometer" of logistics transportation.And it has a strong market potential because it is not affected by the limited time and road of traditional vehicles.The design of the vehicle control unit and the driving control strategy of the pure electric minivan are the development demand of the pure electric minivan and conform to the development trend of the market.This subject takes the M70 pure electric minivan of the Liuzhou Yan Long Automobile Co.,Ltd.as the research object,combined with the development and research status at home and abroad and through the study of the design and driving control strategy of the vehicle controller of the pure electric minivan,the vehicle management and safety and stability drive are realized.It meets the performance requirements of acceleration and endurance mileage of transport vehicle.The main contents of this paper are as follows:(1)The vehicle structure and working principle of the pure electric minivan are studied and analyzed.The vehicle structure of the pure electric minivan is introduced and explained in detail,which lays the foundation for the next step of the design of the vehicle controller,and introduces the function and design requirements of vehicle control unit.The definition of vehicle controller interface for the pure electric minivan is also explained.(2)Describe the principle and main functions of vehicle controller,and design the frame structure of vehicle control unit.The schematic diagram of all hardware modules of the vehicle control unit is designed and explained,and then the anti-interference ability of the vehicle control unit is designed,and the four indexes of electromagnetic compatibility,anti-seismic impact,heat dissipation capacity and power supply voltage bearing capacity are determined.Finally,the hardware implementation of the vehicle control unit is explained.Through the PCB diagram and hardware physical map of the vehicle controller,it is proved that the hardware design of the vehicle controller is successful.(3)The software design of the vehicle control unit of the pure electric minivan is divided into five parts,which are the self inspection of the vehicle control unit,the high voltage up and down electricity,the fault detection and management,the CAN bus receiving and the control strategy of the vehicle equipment,and the detailed description and design of the five parts are carried out.The design of the online software upgrade platform for the vehicle control unit is designed.The hardware requirements,the platform construction process,the program design and the functional test of the vehicle control unit online software upgrade platform are described in detail.The test results show that the online software upgrading platform is designed successfully.(4)The motor drive control strategy of the vehicle control unit of pure electric minivan is designed.The motor drive control strategy is composed of two parts of the motor system efficiency map graph interpolation table and the fuzzy controller.The map graph interpolation table strategy of the motor system efficiency is analyzed.The efficiency map diagram of the motor system is divided into two states of the feed and the normal.The design of the map graph interpolation table for the efficiency of the motor system is described in detail;the membership function of the fuzzy controller's input-output fuzzy quantity is designed and the fuzzy rule of the fuzzy controller is formulated.Finally,the simulation of the driving control strategy is carried out.The simulation results verify the feasibility of the motor drive control strategy.(5)The actual vehicle testing is analyzed and explained,and the actual vehicle testing of the vehicle controller is divided into three cases of vehicle air rotation,blocking and road test.The actual torque of the motor,the given torque of the motor,the speed of the motor and the speed of the accelerator pedal are tested respectively in the three cases,and the results of each test verify that the design of the vehicle control unitfor the pure electric minivan achieves the desired effect.The characteristics and innovation of the paper:(1)The whole vehicle control unit of the pure electric minivan is designed,and the self inspection strategy of the whole vehicle controller is designed and explained in detail.The design of the vehicle controller provides a reference for the design of the controller of the N1 type pure electric vehicle.(2)The motor drive control strategy is designed,based on two states of the motor normal and feed system efficiency map diagram,the efficiency interpolation strategy of the motor system is designed.At the same time,the driving intention of the vehicle is identified by the fuzzy controller according to the speed of the accelerator pedal and the rate of change,and the drive control strategy is combined with the two driving control strategies.Dynamic control strategy can not only satisfy vehicle dynamic performance,but also improve vehicle economic performance.(3)Through the actual vehicle test,the limit condition,the acceleration performance and the endurance mileage of the vehicle are tested.The control effect of the vehicle controller satisfies the acceleration performance of the pure electric minivan and the technical requirements for the endurance of the mileage.