Research On Hub Motor Driving System Of Four-Wheel Driving

With the rapid advancing of automotive industry and the daily growing environmental awareness,the contradictions between traditional vehicles exhaust emissions and today's environmental protection has become more and more prominent.The new energy vehicles which are mostly represented by electric cars have been addressed as a solution and breakthrough of automotive industry development and low-carbon environmental protection.Owing to its structural performance superiority,the Four Wheel Drive electric cars have become the focus of the development for electric vehicles.The driving is mainly a brushless DC hub motor.The driving control system is focusing on controlling the action of the entire four-wheel hub motor coordination which determines the success of its four-wheel independent driving.Therefore,researches about the driving system of four-wheel driving electric motors produced predominating studies in today's industry and universities.In response to these questions,this essay will be talking about the studies concerning the hub motor drive system of four wheel drive electric vehicles.The difficulty of automotive electric control lays on the stabilization ability of the electrics while experiencing different working states.The main researches are as follows:First of all,the article describes the development and innovations of four wheel driving hub motor driving technology.On top of this basis,it introduces the PID control theory for electrics control,moreover it discusses some traditional methods for PID parameters settings.In addition,brought forward the parameters searching method that has applied the recent emerged group intelligent optimal algorithm for PID's three parameters.Secondly,the construction of a four wheel independent drive vehicle model with Simulink platform is done.It shows the electrics which is built in accordance with the external features between motor's voltage volume and revolution speed.Then it simulates the whole vehicle model under different circumstances,which shows a better dynamic adjustment of fourwheel driving electric vehicles among various road conditions.This has laid the foundation for researches focusing on hub motor driving control.After the comprehension of the completely dynamic characteristic of the vehicle,The study of wheel hub motors that is represented by the brushless DC motor is also carried out.A brushless DC motor Simulink model is established and simulation with PID control is run.Under the difficulties of model operation instabilities,the "Firefly Algorithm" is addressed to optimize PID parameters.In addition,the optimization results is applied into the PID controller for simulating,which indicates that The Firefly Algorithm provides good effects on motor stabilization.Furthermore,based on the emulation results,The PID optimization results is verified by an experiment with STM32 microcontroller employed and a motor control software is programmed which based on MDK platform.PID parameters is varied constantly during the experiment in order to verify the practical value of the Firefly Algorithm Optimization.The experimental results show that there is a large discrepancy between motors running with different PID parameters.The Firefly Algorithm Optimization for PID parameters is proven that has a practical application value.