The Research About Location And Guidance Of Differential Wheel Mobile Robot Based On Pid

Nowadays, Mobile robot subject is very young,its foundation include many projects and subjects,such as mechanism, electronic, computer and society science.Self-determination mobile robot amplify working space, and replace humanity works in the space and region that is dangerous or difficult for man.The subject of this thesis is one vehicle in the laboratory.Author analyzes the characteristic about mechanical configuration and then reseaches kinematics equation, that supply academic base for point to position movement. Electronic compass sensor and ultrasonic sensor are installed to controll heading and position for the robot.The whole system adopt decentralization mode,one PC is epigyny, two single chip computer is hypogyny.Author compiles one interface between PC and single chip computer. PID arithmetic is compiled to change speed of motor, in order to measure and control the heading of robot.This paper analyze advantages and disadvantages about different kinds of wheel.and then the configuration of three wheels and differential driving mode is selected.that means two back wheel drive,turning and moving depend on rotate speed difference.Front wheel is versatile,its movement does not effect AGV at all.Then author detrudes kinematics equation, robot can go straight, go round, go helix and turn in the condition that center of mass is immobile.As a result of the movement between wheels and ground is non-holgnomic, phenomena of skid must happen.As a result, aberrancy and mistake come into being. In order to solve the problem of guidance and location, author construct one idea that using electronic compass and ultrasomic sensor, PID arithmetic is adopted.So the heading and location of AGV is measured and modulated real-time.Decentralization mode system is adopted, one PC is epigyny,its obligation is getting datas and information from sensor,and verdict locationo and guidance of AGV.Command and instruction is conveyed to single chip micro computer from PID arithmetic.Hypogyny compose of two AT89C51,the obligation of it is to control step motor.In virtue of guidance and location,RS-485 communication agreement is utilized among epigyny,hypogyny and sensor.Finally,author compiles interface with Visual Basic language,the buttons of going straight,going round,going helix and turning in the condition that center of mass is immobile are included.Heading parameter and feedback information is appeared syllabify, supply help to manipulator.