Research On The Vehicle Controller Unit For Wheel Drive Motor Electric Vehicle

With the intensification of non-renewable energy consumption,environmental pollution has become increasingly serious.People all over the world once again paid much attention to the development of electric vehicles,Wheel hub electric vehicle,compared with traditional car its structure is greatly simplified,the vehicle quality to reduce,and the transmission efficiency is improved.With more space utilization and meeting the new direction of electric vehicle development.So,developing a high-performance,safe and reliable vehicle controller is particularly important for the development of the electric vehicle industry.In this paper,research objective is based on Hub motor electric vehicle controller,After consulting numerous relevant documents,gained a full understanding of vehicle controller,using STM32 series controller.Theoreticl research on wheel motor,working principle and conmmon strategy basis,and study the theory of Ackerman steering principle,Based on this,a simple vehicle controller is designed and tested.The specific steps are as follows.Firstly,this paper introduces the background and significance of electric vehicles,considering the advantages and disadvantages of various motors to determined the type of brushless DC motor,description its working principle,and control strategy.Followed by,The differential principle is analyzed between traditional car and electric vehicles,Based on the Ackermann principle and related references,the differential model of low speed steering of electric vehicle is established.The results of simulation of the electronic differential of electric vehicle are consistent with the conclusions of the reference literature,which shows that the differential model of electric vehicle has Certain rationality and reliability.the result of the MATLAB modeling simulation of two-wheel drive electric vehicle is same as the reference simulation,It also indirectly proves that the correctness,rationality and reliability of the rear-wheel drive electric vehicle model based on the Ackermann principle.Then,based on the functional requirements of the vehicle controller,designed the overall structure and block diagram of the vehicle controller,the various hardware circuit parts are designed in detail,including the minimum system,power inverter circuit and drive circuit,rotor Position detection circuit,communication module circuit,analog-to-digital and digital-to-analog conversion principle and other peripheral circuit design,and draw its schematic.And then,In the software section,Based on control strategy,the overall framework diagram of the control process is drawn,and each sub-module is designed according to the hierarchical design of the module,the flow chart is drawn,and the corresponding software control C program code is written for each sub-module.Finally,the function of the vehicle controller designed is compared with the physical test and simulation results.The comparison of the test results shows that the designed differential control algorithm is effective,the controller function test is stable,safe and reliable.Tested under no-load conditions,when the vehicle speed is 1m/s and the steering angle is 35°,the minimum error of the electronic differential is 0.80%;when the vehicle speed is 4.5m/s and the steering angle is 35°,The maximum error of the electronic differential is 7.6%.This paper,Research on the vehicle controller unit for wheel drive motor electric vehicle,mainly designed the electronic differential control system,achieved the electronic differential in the test process,and the effect was good.Implemented part of the functions of the vehicle controller,with a certain practical significance.