Difference Speed Steering Control Research On Four Wheel Independent Drive Electric Vehicle Experimental Platform

Four wheels independent driving electric vehicle can reasonably control and distribute the wheels' torque and speed,making each tire can become the active driving wheel,according to requirements and traffic information,so that the car has a better grip,acceleration and steering flexibility.This thesis studies the differential speed steering control of the experimental platform of the four wheel independent electric vehicle.In this thesis,the working principle and the driving mode of the brushless DC motor are firstly analyzed,and the mathematical model of the brushless DC motor is established.Then analysis the traditional front wheel differential drive steering Ackermann-Jeantand characteristic function model,the reverse of the front and the rear wheels differential rotation speed steering the characteristic function of derivation,verification and establish front and rear wheels reverse rotation difference speed steering model.Using genetic algorithm optimization control rules of the fuzzy PID control strategy in the MATLAB environment for steering process simulation.The simulation results show that the design of four wheels electrical difference speed steering system can achieve better coordinated control of each car wheel's speed,realize the stationary traveling in the course of the medium and small angle.The feasibility of the backward rotation differential steering control method and the validity of the fuzzy PID control strategy for genetic algorithm are verified.Using STM32 as the control chip,the design of the signal output circuit and detection circuit feedback.The main strategy control program,can control motor speed control procedures,the software design.