Automated Guided Vehicle

AXIS COLLEGE OF ENGINEERING & TECHNOLOGY

Murikkingal P.O, Thrissur

(Affiliated to University of Calicut)

DEPARTMENT OF MECHANICAL ENGINEERING

MINI PROJECT REPORT

FABRICATION OF AUTOMATIC GUIDED VEHICLE

AJITH ARAVIND

JESBIN JOHNSON

VINOD.K.J

VISHNU.T.SAJEEVAN

Fabrication of Automatic Guided Vehicle

AXIS COLLEGE OF ENGINEERING & TECHNOLOGY

P.O.MURIKKINGAL, THRISSUR

DEPARTMENT OF MECHANICAL ENGINEERING

CERTIFICATEThis is to certify that this Project Report Titled

FABRICATION OF AUTOMATIC GUIDED VEHICLE

was carried out by the sixth semester students of Mechanical engineering in

partial fulfilment of the requirement for the award of Bachelor in Technology in

mechanical engineering Under University of Calicut during the year 2012-2013,of

Axis College of Engineering & Technology, Thrissur

AJITH ARAVIND, JESBIN JOHNSON, VINOD.K.J, VISHNU.T.SAJEEVAN

are members of the batch

Project Guide

Joffin Jose P S.Krishnanunni

Project Coordinator H.O.D Mechanical Engg

Place: Thrissur

Date:


ACKNOWLEDGEMENT

We express our deep sense of gratitude and indebtedness to Asst Prof. S.Krishnanunni, Head,

Department of Mechanical Engineering for his valuable advice, constant encouragement and

constructive criticism during the course of the project and also during the preparation of this

manuscript, We place on record the valuable suggestions and numerous constructive comments

rendered by Asst Prof. Joffin Jose.P, Lecturer, Department of Mechanical Engineering and for

being our internal guide in the design and implementation of our project.

We are highly indebted to the staff members of Mechanical Department, especially

Asst.Professors Clint.K.S, Krishnakiran.T.T, Jineesh.V.V, Sankar Raj, Renjith for their

wholehearted support and co-operation.

We also express our sincere thanks to all the classmates for their support and co-

operation in completing the project work.

Above all, we should express our supreme gratitude to almighty God.


ABSTRACT

The Automatic Guided Vehicle refers a type of system that can be used in production as well

as in other industries etc. This system includes a battery operated remote sensing locomotive

(carrier) on which a small lift is provided, specific path over which it moves, sensors for

sensing the the obstructions on the path of the carrier. Also sensors for sensing exact

positions from where load wants to carry and to where.

The remote sensing carrier moves using the electric power from the battery. It moves

with a low and constant speed on the prescribed path. The path has a specific color. The

bottom of the carrier have sensor which is always coupled with the path. From the remote

station we send only information for moving the carrier, not for steering it. The steering is

done by the path. The front side of carrier vehicle contains sensors for sensing the

obstructions on the path.

As it reaches the collecting station, its top floor lift to a small distance and lift the

stand which contains the parts wants to assemble, supply. And the carrier moves through the

path and reaches the supply station. The sensor provided on the carrier detected the station

and unload the stand contains assembly parts at that station. And move to collecting stations

again. Continues working cycles for making this project a reality.

4Department of Mechanical Engineering ACET


TABLE OF CONTENT

CHAPTER TITLE PAGE

CHAPTER I: INTRODUCTION

1.1 Automatic Guided Vehicle 1

1.2 Background 3

1.3 Problem Statement 3

1.4 Project and It’s Scope 5

1.5 Market Survey 6

CHAPTER II: LITERATURE REVIEW 7

2.1 AGV Built Worldwide Used 10

2.2 Mobile Post Distribution System (MOPS) 11

2.3 The Parkshuttle AGVs of Amsterdam’s Schiphol Airport 12

2.4 Line Following Robot 13

2.5 The Kerwin’s Line Following Robot 13

CHAPTER III: COMPONENTS SELECTION AND DESCRIPTION 14

3.1 Design Objectives 14

3.2 Design Considerations 15

3.3 Components of AGV 17

3.4 Mechanical Part 19

3.4.1 Chassis 19

3.4.2 Steering System 20

3.4.3 Lifting Mechanism 22

3.5 Electrical Components 24

3.5.1 DC Motor 24

3.5.2 Battery 25

3.6 Electronics Components 26

3.6.1 Microcontroller 26

3.6.2 Motor Driver 29



3.6.3 Regulators 33

3.6.3.1 7805 Regulator 33

3.6.3.2 LM317 Regulator 34

3.6.4 IR Sensor 35

3.6.5 Magnetic Sensor 38

3.6.6 Display Unit 40

3.7 Software Components 42

3.8 Program Source Code 43

CHAPTER IV: DEVELOPED PROTOTYPE 50

4.1 Structure 50

4.2 Sensors Positions 52

4.3 Flow Chart 54

4.4 Block Diagram 55

4.5 Circuit Diagram 56

4.6 Theoretical and Logical Calculations 58

4.7 Billing 61

CHAPTER V: CONCLUSION 62

REFERENCES 64

LIST OF TABLES



Table Number Title Page

2.1 Line Following Methods 13

3.1 Technical Data for Chassis 19

3.2 Steering Specifications 21

3.3 Motor Specifications 24

3.4 Battery Specifications 25

3.5 Specifications of ATmega 328 27

3.6 Important Connections 27

3.7 Technical Specifications of L293D 32

3.8 Maximum Rating of 7805 33

3.9 Technical Specifications of 7805 34

3.10 Technical Specifications of LM 317 34

3.11 Technical Specifications of IR Pair 37

3.12 Technical Specifications of Magnetic Sensors 39

3.13 Technical Specifications of Display Unit 40

3.14 Pin Configuration 40

4.1 Billing Table 61

LIST OF FIGURES

Figure Number Title Page

2.1 The Mobile Post System 11

2.2 The Parkshuttle AGV’s of Amsterdam 12

2.3 The Kerwin’s Line Following Robot 13

3.1 Chassis of AGV 19

3.2 Differential Steering 20

3.3 Small Radius Turning 21

3.4 Lifting Using Threaded Shaft 22

3.5 Structure of Lift 23

3.6 DC Motor with Gearbox 24

3.7 Battery 25

3.8 ATmega 328 Microcontroller 28

Figure Number Title Page



3.9 Motor Driver (L293D) 29

3.10 L293D Connected with Two Motors 30

3.11 L293D Connected with One Motor 30

3.12 Circuit Connection of Driving Motor 31

3.13 Connection of Lifting Motor 31

3.14 PWM 32

3.15 7805 Regulator 33

3.16 LM 317 Circuit 34

3.17 IR for Path Detection 35

3.18 IR Pair Circuit 36

3.19 Magnetic Sensor 39

3.20 Application Circuit of Display Unit 41

4.1 Front View of AGV 50

4.2 Top View of AGV 51

4.3 IR Sensor Positions of AGV 52

4.4 Magnetic Sensor Positions 53

4.5 Flow Chart 54

4.6 Block Diagram 55

4.7 Circuit Diagram 56

4.8 Fully Developed Prototype 57



CHAPTER I

INTRODUCTION

1.1 AUTOMATED GUIDED VEHICLE

An automated guided vehicle or automatic guided vehicle (AGV) is a mobile robot that

follows markers or wires in the floor, or uses vision or lasers. They are most often used in

industrial applications to move materials around a manufacturing facility or a warehouse

Automated guided vehicles increase efficiency and reduce costs by helping to

automate a manufacturing facility or warehouse. The AGV can tow objects behind them in

trailers to which they can autonomously attach. The trailers can be used to move raw

materials or finished product. The AGV can also store objects on a bed. The objects can be

placed on a set of conveyor and then pushed off by reversing them. Some AGVs use forklifts

to lift objects for storage. AGVs are employed in nearly every industry, including, pulp,

paper, metals, newspaper, and general manufacturing. Transporting materials such as food,

linen or medicine in hospitals is also done.

An AGV can also be called a laser guided vehicle (LGV) or self-guided vehicle

(SGV). Lower cost versions of AGVs are often called Automated Guided Carts (AGCs) and

are usually guided by specific lines magnetic tape. AGCs are available in a variety of models

and can be used to move products on an assembly line, transport goods throughout a plant or

warehouse, and deliver loads to and from stretch wrappers and roller conveyors.AGV

applications are seemingly endless as capacities can range from just a few kgs to hundreds of

tons. The Aim of the project is to design and fabricate such a AGV

There are many definitions of AGVs, different according to points of view.

Wikipedia, the free encyclopedia, defines AGVs as:

“A robot that been used highly in industrial applications to move materials from point to point”



The American Society of Safety Engineers (ASSE) defined AGVs as:

a. Machines without drivers that can move along pre-programmed routes, or use sensory and navigation devices to find their own way around.

b. Vehicles that are equipped with automatic guidance systems and are capable of following prescribed paths. Or Driverless vehicles that are programmed to follow guide path



1.2 BACKGROUND

The creations of Automated Guided Vehicle (AGV) have been around since the 1950’s and

the technology was first developed by Barret Electronics from Grand Rapids, Michigan. It

was then developed by the Europeans in the 1970’s and nowadays AGVs can be found in any

countries. One of the first AGVs was a towing vehicle that pulled a series of trailers between

two points, and today’s there are many task given to AGVs and they also have their own

name and potentials.

Considering the full potentials and advantages of the Automated Guided Vehicle

(AGV) in our livings, it is valuable to do this project, as it also will be the first step towards

the creation of more intelligent technology or system. The simplest AGV model may use just

a sensor to provide its navigation and can be the complex one with more sensors and advance

systems to do the task. They can work or do the task everywhere needed but the safety for the

AGV as well as the people and environment surround it must be provided.

The AGVs is just the same as mobile robot, which can moves from one place to another

to do their task, but mostly the mobile robot is used for difficult task with dangerous

environment such as bomb defusing. Furthermore, the mobile robot can be categorized into

wheeled, tracked, or legged robot. Although the AGVs may not be glamorous of robots, but

their work, which usually menial, are often be essential to the smooth running of factories,

offices, hospitals, and even houses. They can work without any complaint around many

workplaces all over the world.

1.3 PROBLEM STATEMENT

There are many reasons which yield to the creation of Automated Guided Vehicle (AGV)

around the world. Mostly the reason is to overcome the logistic problems that often occurred

in the workplaces and to make improvement to the facilities provided in the workplaces.

Usually the AGVs are implemented in factories, hospitals, offices, houses, and even can be

found anywhere outdoors without the people surround realized it.



In the industries or factories, the AGVs can ease the physical strain on human workers

by performing tiring tasks, such as lifting and carrying heavy materials, more efficiently with

no signs of fatigue creeping in. They can carry far more than human workers, and their

movements can be tracked electronically at all times. Their movements can be timed to feed

or collect products or materials from the work cells in the factories.

Besides that, in the hospitals thousands of staff spends a portion of their day moving

medical supplies, bedding, medicines and other equipment around large hospitals. By using

the AGVs, the strain on the workers can be ease as well as the hospital’s system would be

more smart and systematic without any bad complaint from the patients and people. AGVs

also capable of both cutting cost and releasing more staff hours to tend and care for patients.

Therefore it is very significant that the valuable knowledge on AGV construction is

studied and be further implemented from the result of this project. It is due to its advantages

to our own living and technology.

We have pleasure in introducing our project AGV, which is equipped by

microcontroller, motor driving mechanism, lift mechanism and battery. The power stored in

the battery is used to drive the DC motor that causes the movement as well as lifting power to

AGV. Battery assembled on the AGV is easily replaceable and detachable, used for

recharging the battery, while the AGV is under roof.



1.4 PROJECT AND ITS SCOPE

The objective and scope of this project is to create an AGV model that can follow a trail of line on a flat surface horizontally. This AGV model is using microcontroller to control all navigation and lifting functions during its operation. In other words, the microcontroller acts just like the brain for the model that controls all operation of the system.

The model is a three-wheeled mobile robot that has the ability to follow line on floor.

There are three wheels including two driving wheels controlled by two motors and a free

wheel in front that is able to rotate 360°. With three wheels, both driving wheels are always

in contact with the surface, because of the robot’s steering relies on both its driven wheels

being in contact with the surface at all times.

This project consists of four main stages, which are theoretical design, mechanical

fabrication, electronic hardware design and as well as algorithm design in assembly language.

The matter to be considered is how the robot can follow the trail of line continuously. It is

also important to choose the most suitable microcontroller, actuators, and sensors to achieve

the project objectives.

.



1.5 MARKET SURVEY

A market survey is an important requirement for initiating any successful business. The

objective of a market survey is to collect information on various aspects of the business. This

survey is a tool through which we can minimize risk. After the market survey, the results

must be analyzed in order to finalize a business plan.

We are implementing automatic guided vehicle, which replaces the normal

transporting methods. So that we wants to consider all the sections related to this works such

as problems arising while installing. So we conducted a market survey by personnel interview

techniques was used with the measure emphasis on personal interview method. Interviews

were conducted through the structure questionnaire, Also we go through people who work in

large industries such as production plant, supply station etc.

The following questions are mainly taken for questionnaire:

Area of applications? i.e. inside/outside/both

Types surface of flooring?

Weights of loads max?

Distance to transportation?

From the data which we got from the market survey we are well know about the

things what the market needed, and what modifications should be taken to the system. And

we analysis the data and make objectives want to goal.



CHAPTER II

LITERATURE REVIEW

Automatic Guided Vehicles (AGVs) have played a vital role in moving material and product

for more than 50 years. The first AGV system was built and introduced in 1953. It was a

modified towing tractor that was used to pull a trailer and follow an overhead wire in a

grocery warehouse. By the late 1950's and early 1960's, towing AGVs were in operation in

many types of factories and warehouses.

The first big development for the AGV industry was the introduction of a unit load

vehicle in the mid 1970s. This unit load AGVs gained widespread acceptance in the material

handling marketplace because of their ability to serve several functions; a work platform, a

transportation device and a link in the control and information system for the factory.

Since then, AGVs have evolved into complex material handling transport vehicles

ranging from mail handling AGVs to highly automated automatic trailer loading AGVs using

laser and natural target navigation technologies. In fact the improvement of AGVs over the

last decade is deeply indebted to development of Scheduling, Algorithm and Steering

methods. The problem of scheduling of AGVs and the other supporting equipments has been

extensively studied by Basnet and Mize and Rachamadugu and Stecke currently providing

the most up-to-date and comprehensive reviews in this area.

Han and McGinnis have developed a real time algorithm in which material handling

transporters are considered. Schriber and Stecke have shown how the additional consideration

of the material handling system and limited buffers degrades the system performance.

Sabuncuoglu and Hommertzheim have highlighted the importance of material handling and

they compared several AGV dispatching rules. They have also shown how the buffer capacity

can affect the performance of the system. Flexibility, which is a distinguishing feature of

FMSs, has received an extensive amount of attention. Routing flexibility (i.e., alternative

machines and processing routes) has been considered by Wilhelm and Shin, Chen and Chung,

and Khoshnevis and Chen . These studies have indicated that dynamic routing (i.e., a path

determined dynamically during schedule generation) performs better than a preplanned

routing.



Rachamadugu et al. Have proposed a quantitative measure of sequence flexibility and

have shown that perfect sequence Flexibility improves system performance. Similar

observations have been made by Lin and Solberg. In most work to date, tools, pallets/fixtures

and their availability are not modeled adequately. A static allocation of tools is usually

assumed in these studies.

However, some researchers have considered a limited tool magazine capacity and the

changing of tools from central tool storage. One purpose of this thesis is to develop an

algorithm that can be used to investigate the research issues discussed above. This algorithm

should not only consider the major elements of FMSs but also generate high quality

schedules in a reasonable amount of time. In this thesis, the basic structure and characteristics

of such an algorithm is described.

Kim et al. Proposed a deadlock detection and prevention algorithms for AGVs. It was

assumed that vehicles reserve grid blocks in advance to prevent collisions and deadlocks

among AGVs. A graphic representation method, called the "reservation graph," was proposed

to express a reservation schedule in such a form that the possibility of a deadlock can be

easily detected. A method to detect possible deadlocks by using the reservation graph was

suggested.

Maxwell and Muckstadt first introduced the problem of AGV flow system design.

While their main concern is vehicle routing, they also address material flow path and station

location design issues. The flow network they used, known as conventional configuration, is

composed of unidirectional arcs. Gaskin and Tanchoco developed the first integer

programming model for material flow path design. Given a fixed network of aisles and fixed

pickup and delivery stations, the model assigns direction to arcs to minimize the total trip

distances of loaded vehicles. Goetz and Egbelu developed an alternative model, where the

station locations no longer are fixed but restricted to the nodes on the boundary of the cells.

Sun and Tchernev provide a comprehensive review on the models developed for conventional

configuration.

Afentakis states the advantages of the loop layout as simplicity and efficiency,

lowinitial and expansion costs, and product and processing flexibility. Loop layout has been

studied by many researchers including Bartholdi and Platzman , Sharp and Liu ,Kouvelis and



Kim , Egbelu , Banerjee and Zhou , and Chang and Egbelu. Bozer and Srinivasan initiate the

concept of tandem configuration as a set of no overlapping, bidirectional loops, each with a

single vehicle.

Another problem in steering issues is to schedule several AGVs in a non-conflicting

manner which is a complicated real-time problem, especially when the AGV system is bi-

directional. In fact, many conflicting situations may arise such as head-on and catching-up

conflicts when the AGVs or the guide-paths are bidirectional and if no efficient control policy

is used to prevent them. Several conflict-free routing strategies have been proposed and can

be classified into two categories:

Predictive methods: Aim to find an optimal path for AGVs. The conflicts are

predicted off-line, and an AGV’s route is planned to avoid collisions and deadlocks.

Reactive methods: the AGVs are not planned and the decisions are taken in a real-

time manner according to the system state.

These methods are based on a zone division of the guide-path and consider them as

non sharable resources. Predictive methods give good performance, but are not very robust

since they do not take into account real time problems. However, reactive methods are very

robust but the resulting performances can be poor because the decisions are taken by

considering a very short-term time horizon. In this report due to specification of the whole

plan (presence of only one AGV) a kind of predictive method is proposed.

In early 1990s Fuzzy logic came through to control and manipulate whole of the

material flow in manufacturing floors. The main indication of employing this system on

AGVs was the ability of controlling multiple AGV in a same time without collision.However,

only simulation results are presented. Senoo et al used experimental results of a three

wheeled mobile robot to discuss the stability of a fuzzy controller. It is also stated that fuzzy

control was implemented in order to achieve reduction of steer energy, while maintaining

better steer angle when compared with PI control.

Fuzzy logic has found useful applications in control among other areas. One useful

characteristic of a fuzzy controller is its applicability to systems with model uncertainty

and/or unknown models. Another useful characteristic of a fuzzy logic controller is that it



provides a framework for the incorporation of domain knowledge in terms of heuristic rules.

Wuwei et al. They presented the new navigation method for AGV with fuzzy neural network

controller when in the presence of obstacles. Their AGV can avoid the dynamic and static

obstacle and reach the target safely and reliably.

Wu et al. used fuzzy logic control and artificial potential field (APF) for AGV

navigation. The APF method is used to calculate the repulsive force between the vehicle and

the closest obstacle and the attractive force generated by the goal. A fuzzy logic controller is

used to modify the direction of the AGV in a way to avoid the obstacle. Lin and Wang

proposed a fuzzy logic controller for collision avoidance for AGV.

They combined fuzzy logic with crisp reasoning to guide an AGV to get out of trap

since memories of path and crisp sequence flows are handled by non-fuzzy processing. Their

designed AGV was able to avoid collision with unknown obstacle. Alves and Junior used a

step motor to turn the direction of the ultra-sonic sensors, so that each sensor can substitute

two or more sensors in mobile robot navigation. Perhaps Sugeno has done one of the

pioneering researches in mobile robot navigation using fuzzy logic control. The fuzzy control

rules, which he defines for the controller, were derived by modeling an expert driving action.

He made a computer model of a car in microcomputer to find fuzzy rules. The speed of the

designed car was constant; then, the control input to the car is only the angle of the steering

angle

Mehdi Yahyaei has design a AGV using fuzzy logic system and a rotational ultra

sonic sensor to steer the AGV to avoid collisions and obstacles. He also employed a

programmable logic control (PLC) as the processor which makes the AGV to be ultimately fit

to the industrial environments.

2.1 AUTOMATED GUIDED VEHICLE BUILT WORLDWIDE

Some of the Automated Guided Vehicles (AGVs) that are well known are discussed

in brief.



2.2 MOBILE POST DISTRIBUTION SYSTEM (MOPS)

MoPS or Mobile Post Distribution System (Tschichold, Vestli, Schweitzer, 1999) is a

research AGV developed at the Institute of Robotics in Zurich, Switzerland. It is used to

transport mail around the Swiss Federal Institute of Technology in Zurich. MoPS is powered

up by rechargeable batteries which give it a 4-hour active life, weighs around 90kg and can

carry up to 50 kg of postal payload. It is also capable of hot-swapping its own batteries pack,

thus ensuring 24h availability.

The MOPS provide services of picking up boxes with incoming mail at the ground

floor of the five floor building, which is sorted by human first, delivering them to the

secretaries' offices, subsequently bringing back the outgoing mail to the ground floor station.

It is also capable of switching floors by sending an infrared signal to the building’s lifts. As

the building is open to the public, protection against theft of the mail is provided by

motorized blinds over the pigeon-hole mail points, which can be opened by the robot and by

authorized staff.

Fig 2.1 The Mobile Post System MOPS



2.3 PARKSHUTTLE AGVS OF AMSTERDAM’S SCHIPHOL AIRPORT

Fig 2.2 The ParkShuttle AGVs of Amsterdam’s Schiphol Airport.

The ParkShuttle (FROG Navigation Systems) is an automatic navigating vehicle which

provides transportation for passengers. It is a people mover system. There is no driver

onboard, instead a computer and an electronic navigation system do the driving. This

ParkShuttle has a safety system of sensitive and intelligent sensors. The sensors scan the area

in front of the vehicle and will decelerate or stop the vehicle when an unknown obstacle is

detected.

An additional safety feature is provided by the bumper system that brings the vehicle

to an immediate halt when it is impressed. In addition, the vehicle has emergency stop

buttons (both inside and outside) that can be operated by the passengers. The speed is limited

to 40 km/h obtain a good ride quality. 8 The ParkShuttle vehicle runs on four rubber tires.

Traction is provided by an electric motor powered by a rechargeable battery. Up to 100 km

can be covered on one battery-load. It has a capacity of 10 passengers, 6 seated and 4

standees. It is easy to get into and out of the vehicle (wheelchair accessible) and provides

good all-round visibility. Inside the vehicle is a console on which the passengers can indicate

their destination.

Each vehicle is also fitted with an information display that announces the stop at which the

vehicle has arrived. The maximum load is 800 kg. The maximum vehicle weight is monitored

by means of weight sensor.



2.4 LINE FOLLOWING ROBOT

Line following robot is generally a wheeled mobile robot. The method of line following

varied depending on the number of sensors available and the type of line to be followed.

There are four methods identified including edge following, line search, line trap, and cross-

over. These four methods are different in number of sensors that used and also the results that

will be obtained are different. With only one light sensor, the robot will have to know where

the line is, or spends time searching to find it. Whereas with two light sensors, the robot is

possible to remember which direction the line went. With more sensors, the result that will be

obtained would be more excellent and the robot will be more intelligent.

Table 2.1 Line Following Method

Method Characteristics

Edge following Stay on the edge of the line

Line search Stay on the line

Line trap Keep the line between the sensors

Cross over Move back and forth over the line

2.5 KERWIN’S LINE FOLLOWING ROBOT

Fig 2.3 The Kerwin’s line following robot using three matched IR transmit/receive pairs

The Kerwin’s line following robot (ranchbots) is a design with Futaba S-148 servo

motors mounted to the bottom of the plexiglass. It has three wheels with the front wheel is the

omni-directional wheel. The sensor system consists of an array of three matched IR

transmit/receive pairs mounted on a circuit board that can be raised or lowered to fine tune



the sensitivity. It uses the Atmel microcontroller as the controller part. The microcontroller

takes input from sensor array and drives the servo motors in response.

CHAPTER III

COMPONENTS SELECTION & DESCRIPTION

3.1 DESIGN OBJECTIVES

In nowadays AGV has a greater influence in the production field. Why we prefer this system

is mainly because of its accuracy to transport goods, avoiding accidents at industrial zone,

decreasing production overall cost etc.

In our project the important factor is that, we give an additional functions to AGV, i.e.

we provide a lifting mechanism to take loads from station to station. The lift will actuate at

those particular stations using sensors. Also we provide a sensor which detects the objects in

the paths to avoid collision with those objects, by stopping the vehicle and moves after the

when object leaves the path.



3.2 DESIGN CONSIDERATIONS

In design problems many decision variables arise. The impact of decisions on mutual

interactions and performance might be difficult to predict. It might be hard to decide on one

thing without considering other decision variables. At least the following tactical and

operational issues have to be addressed in designing an AGV system

• Flow path layout

• Traffic management: prediction and avoidance of collisions and deadlocks

• Number and location of pick-up and delivery points

• Vehicle requirements

• Vehicle routing

• Vehicle scheduling

• Battery management

A flow path layout compromises the fixed guided paths on which vehicles can travel

to the various pick-up and delivery points of loads. Traffic management is required to avoid

collisions and deadlock situations in which two or more vehicles are blocked completely. To

ensure that loads are transported in time, sufficient vehicles should be available and the right

vehicle should be dispatched to the right load.

This layout is usually represented by a directed network in which aisles intersections

and pickup and delivery locations can be considered as nodes. The arcs represent the guide

path the AGVs can travel on. Directed arcs indicate the direction of travel of vehicles in the

system. The layout of this flow path directly influences the performance of the system. In our

project we just mark two stations only. One loading and one unloading station. The carrier

moves in the loop which connects these two stations.

In controlling and designing AGV systems the problem of prevention of AGV

collisions and deadlocks should be addressed. By attaching sensors on AGVs, physical

collisions can be avoided. An AGV should have the ability to avoid obstacles and the ability

to return to its original path without any collisions. We had fabricated only one AGV. So the

traffic management has only less important in our case. But while using more than one carrier

we should take care about them.



To determine an optimal AGV’s system, capable of meeting all requirements, many

factors have to be taken into account. Several of these factors are:

• Number of units to be transported

• Points in time at which units can be or need to be transported

• Capacity of the vehicle

• Speed of the vehicle

• Costs of the system

• Layout of the system and guide path

• Traffic congestion

• Vehicle dispatching strategies

• Number and location of pick-up and delivery points

If AGVs use batteries, frequent battery changing might be required. McHaney (1995)

presents an overview of AGV battery technology. The time required for replacing or charging

batteries can impact the number of vehicles required. Simulation results from McHaney

(1995) indicate a significant increase in the number of AGVs required while incorporating

battery management issues in the simulation study compared to neglecting these issues in the

studies. Furthermore, the time required for charging batteries impacts throughput, congestion

and costs.



3.3 COMPONENTS OF AGV

1. MECHANICAL PARTS

The Mechanical components includes,

1. Chassis

2. Steering system

3. Lift mechanism

Chassis

Act as a frame for attaching other components

Carry the load of other components and the payload.

Act as sacrificial component to prevent damage of expensive payload in case of

accidents

Steering System

Steering system is for steering the AGV. The two individual motors are directly attached with

the wheel for steering

Lifting Mechanism

Lifting mechanism is one of the main part of AGV, the lifting surface moves upward and

downward at specified stations. And carry the load during load transfer.



2. ELECTRICAL COMPONENTS

Electrical components include the motor and the power supply unit for the motor, sensoring

unit

3. ELECTRONIC COMPONENTS

Electronic components provide sensing, logical decision and control of the vehicle. It

includes microcontroller, which is the brain of the vehicle for the decision logic, the motor

driver as both sensing and control of motor, regulator ICs, LCD Display unit, sensors for

sensing the path, position of loading and unloading stations, detect object in the path etc.

4. SOFTWARE COMPONENTS

Computer is used for making and implementing program for the microcontroller, using

embedded computer programming language. For this project we use Arduino Uno

microcontroller board based on the ATmega328 .The Arduino Uno can be programmed with

the Arduino software.



3.4 MECHANICAL PART

3.4.1 CHASSIS

The chassis is fabricated from Acrylic sheet. This is done for ease of fabrication, and to

reduce the overall weight. It was designed in Catia; part of fabrication was outsourced due to

unavailability of precision cutting tools. The chassis was designed to take a static load of 3kg.

The Top part of chassis has lots of drilled holes which serves as holes for bolting

other parts and reduce the weight of the chassis. The Holes are arranged in a zigzag linear

arrangement so that the decrease in strength of chassis is not considerable.

The flange which holds the motor was designed using Aluminium and is bolted to the

chassis. So that the driving motors can easily accommodate below the chassis. The chassis

incorporates hole for attaching front globe wheel, and also for attaching the lift structure

Fig 3.1 Chassis of AGV

Table 3.1 Technical Data of ChassisFeatures DataLength 300mmBreadth 160mmHeight 62mmMaterial Colored Acrylic sheet, AluminumMaximum loadMounting Holes 14×3mm ø Holes for general mounts

2×8mm ø Holes for motor1×10mm ø Hole for switch



3.4.2 STEERING SYSTEM

The steering system used in the model is of differential type. A differential wheeled vehicle is

a vehicle whose movement is based on two separately driven wheels placed on either side of

the body. It can thus change its direction by varying the relative rate of rotation of its wheels

and hence does not require an additional steering motion. It allows the turning center to be on

the vehicle body thus the ability to rotate on the point

Fig3.2 Differential Steering

If both wheels rotate at the same speed and in the same direction, the robot will move

in a straight line.



Fig 3.3 Small radius turning

If one of the wheels is stopped, while the other continues to rotate, the robot will pivot

around a point centred approximately at the mid-point of the stopped wheel.

Table 3.2 Steering Specifications

Feature DataWheel Base 180mmWheel Diameter 70mmTrack Distance 170mmMaterial Rubber and plasticTurning radius 190mm



3.4.3 LIFTING MECHANISM

The lift is the main component of this AGV. The lift takes and gives loads at specific stations.

The vehicle under stands the stations using sensors. Lift is attached in the front portion of the

chassis. The power for lift is transmitted from a motor using a threaded shaft.

The lift consists of mainly two plates. One is centrally drilled and tapped. Second

plate is attached with the lower one, using bolts, at a distance. The shaft of the motor drilled

axially and made internal threads using tap. Both the plates moves in between two guide

ways. The threaded shaft is passed through the centrally tapped hole of lower plate.

During the rotation of shaft the lower plate moves up or down. And the upper plate

moves according to it. The time for the rotation is limited for few seconds. It can be adjusted

by making changes in the microcontroller program. A magnet is attached above the upper

plate, which helps to hold the items to be lift, which have magnetic behavior.

Fig 3.4 Lifting using threaded shaft


4

3

1

2


In order to reduce the overall cost and weight of the AGV, we used acrylic sheets for

the manufacturing of lifting surfaces, Aluminum C channels for the guide ways in between

the plates moves are used for the fabrication.

Fig 3.5 Structure of lift

1. Guide ways

2. Threaded shaft

3. Lower plate

4. Upper plate



3.5 ELECTRICAL COMPONENTS

3.5.1 DC MOTOR

100 RPM DC Motor with Gearbox generally used for robotic application are used for the

driving mechanism, steering mechanism and lifting mechanism. We can adjust it to desired

RPM using gear box. Very easy to use. It is excellent for line tracking robotic application.

Fig 3.6 DC Motor with Gear box

Table 3.3 Motor Specifications

Feature DataSupply voltage 12V DCSpeed 100 RPM with gear boxShaft Diameter 6mmWeight 125gmTorque 12KgcmNo-load current 60mA(Max)Load current 250ma(Max)



3.5.2 BATTERY

The power required for the entire working process is given by a Rechargeable valve regulated

Lead-Acid battery. The power from the battery is split it into two and one part is given to

microcontroller, display unit, driving unit and other part is given to lifting motor.

Fig 3.7 Battery

Table 3.4 Battery SpecificationFeatures DataSpeed 100rpmVoltage 12V DCTorque 12Kg-cmNo load current 60mALoad current 250mA



3.6 ELECTRONICS COMPONENTS

3.6.1 MICROCONTROLLER

A microcontroller (µC, uC or MCU) is a small computer on a single integrated circuit

containing a processor core, memory, and programmable input/output peripherals.

Microcontrollers are designed for embedded applications, in contrast to the microprocessors

used in personal computers or other general purpose applications.

We use ATmega 328 in our AGV.The Atmel®AVR® ATmega 328 is a low-power

CMOS 8-bit microcontroller based on the AVR RISC architecture. By executing powerful

instructions in a single clock cycle, the ATmega8 achieves throughputs approaching 1MIPS

per MHz, allowing the system designed to optimize power consumption versus processing

speed.

The reasons for using ATmega 328 are:

Low cost

Easy to program

High-performance, Low-power

Fully Static Operation

High Endurance Non-volatile Memory segments

Power-on Reset and Programmable Brown-out Detection

Internal Calibrated RC Oscillator

External and Internal Interrupt Sources

High stress value

Five Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, and

Standby

I/O and Packages

23 Programmable I/O Lines

28-lead PDIP, 32-lead TQFP, and 32-pad QFN/MLF

Operating Voltages

2.7V - 5.5v to 4.5V - 5.5V



The Microcontroller is programmed with the required program to accept the data from

the sensing unit, interpret it, and give responses to the driving and lifting mechanism in very

small time interval.

Table 3.5 Specification of ATmega 328

Type: 28Pin DIP PackageFlash 32K BytesI/O pins 23 PinsMinimum/Maximum Voltage: 1.8/5.5VMaximum current: 20mANumber of PORTS 4No of channels 6Bus width 10BitOscillation Speed 20MhzPWM 6

Table 3.6 Important Connections

PIN Name Pin No

Vcc 7

GND 8,22

XTAL1 9

XTAL2 10

RXD/PD0 2

PB4 16

PB5 19

PB6 9

PB7 10

Reset 1

Rxd 2

Txd 3

AVCC 20

AREF 21



Fig 3.8 ATmega 328 microcontroller



3.6.2 MOTOR DRIVER

It is an electronic circuit which enables a voltage to be applied across a load in either

direction. It allows a circuit full control over a standard electric DC motor. That is, with an H-

bridge, a microcontroller, logic chip, or remote control can electronically command the motor

to go forward, reverse, brake, and coast.

A "double pole double throw" relay can generally achieve the same electrical

functionality as an H-bridge, but an H-bridge would be preferable where a smaller physical

size is needed, high speed switching, low driving voltage, or where the wearing out of

mechanical parts is undesirable. The term "H-bridge" is derived from the typical graphical

representation of such a circuit, which is built with four switches, either solid-state (e.g.,

L293/ L298) or mechanical (e.g., relays).

In our AGV we use the driver IC L293d. There are two driver ICs are provided in the

design, because three motor are in the AGV. One driver circuit is connected to the two

motors of driving mechanism. And second one is used for the motor which is incorporated

with the lift.

Fig 3.9 Motor Driver (L293D)



The following figure shows the connection of the driving mechanism.

Fig 3.10 L293D connected with two motors

To simplify use as two bridges each pair of channels is equipped with an enable input.

A separate supply input is provided for the logic, allowing operation at a lower voltage.

This device is suitable for use in switching applications at frequencies up to 5 kHz.

In the lifting section one motor is utilized. So the one side of the driver circuit is not

connected.

Fig 3.11 L293D connected with one motor



In the both end of a motor voltage is always 5v. So there no potential difference between the

two terminals of the motor. Therefore there is no current flow between terminals, and motor

will not work. During the operation at one terminal the voltage becomes zero volts. And thus

the current flows through the motor and it works. We can rotate the motor in two directions.

In the driving mechanism, in our design one direction of rotation of motor is needed.

Because the AGV doesn’t wants to moves in reverse. But the connection is made in such a

way that both two motors rotate in opposite direction. i.e., the motor which rotates the right

wheel in clockwise direction and that of left wheel rotates in counter clockwise direction.

But the lifting motor wants to rotate in the both directions. For the clock wise rotation

lift move up and for counter clockwise it moves down. The movement of the lift surface

depends on the internal thread of the lower plate also.

Fig 3.12 Circuit connection of driving motor

Fig 3.13 Connection of lifting motor for clock wise and counter clock wise rotation



To control motor speed we can use pulse width modulation (PWM), applied to the enable

pins of L293d driver. PWM is the scheme in which the duty cycle of a square wave output

from the microcontroller is varied to provide a varying average DC output.

Fig 3.14 PWM

Table 3.7 Technical Specification of L293D

Symbol Parameter DataVs Supply Voltage 36VVss Logic Supply Voltage 36VVi Input Voltage 7VVen Enable Voltage 7VIo Peak Output Current 1.2APtot Total Power Dissipation at Tpins=90ᵒc 4WTstg,Tj Storage and Junction Temperature -40 to 150 ᵒc



3.6.3 REGULATORS

Mainly two types of voltage regulators are used in the design. One is variable and the next is

not. The non variable belongs to 78 series. And variable is LM series. The main supply is

12V. But we need only 5V. It is made possible using these regulators

3.6.3.1 7805 Regulator

It is the one of the important electronic part. The motor, driving IC, microcontroller etc need

only 5V for their operations. Before the supply is given to these circuits it is given to the

7805 voltage regulator. It reduces the voltage from 12V to 5V.

Fig 3.15 7805 REGULATOR

The main features of these regulators are:

Internal Thermal Overload Protection.

Internal Short Circuit Current Limiting.

Output Current up to 1.5A.

Satisfies IEC-65 Specification.

Table 3.8 Maximum Ratings of 7805

Characteristic Symbol RatingInput Voltage Vin 35VOperating Junction Temperature

Tj -40 to 150 ᵒc

Storage Temperature Tstg -55 to 150 ᵒcMax. junction Temperature Tj(max) 150 ᵒc



Table 3.9 Technical Specifications of 7805

ELECTRICAL CHARACTERISTICS (VIN=10V, IOUT=500mA, 0ᵒc≤ Tj≤ 125ᵒc)Characteristic DataOutput Voltage 4.8 to 5.2 VInput Regulation 100 mVOutput Noise Voltage 50 microVrmsRipple Rejection Ratio 78dBDrop Out Voltage 2.0V

3.6.3.2 LM317 VARIABLE REGULATOR

There are five variable regulators are used in our design. Its used for reduce the

voltage to the motor and to sensors. It will helps to reduce the speed of rotation of the

motor and thus we can adjust the speed of the vehicle.

Fig 3.16 LM317 circuit

Table 3.10 Technical Specificationsof LM 317

Parameter DataLine Regulation 0.01 %/VLoad Regulation 0.1%/VThermal Regulation 0.04%/WCurrent Limit 2.2ARipple Rejection Ratio 65dBLong term stability 0.3%RMS Output Noise 0.003%



3.6.4 INFRARED SENSORS

IR Sensor is one of the important parts. Path detection and obstrucle detection is done with

the help of IR Sensors. There are five IR Sensors are in our AGV. Out of them four are used

for the path detection and rest of one is used for obstrucle detection.

IR sensor have a transmitter and a receiver port.

The strength of signal reached at the receiver port after the reflection of light is used

to detect the path. Path is marked in the black background by white lines. Sensor detect the

white line by the strength of IR wave. The reflected wave from white line has high strength

than that of from black. TSOP1730 are used in the design.

Fig 3.17 IR for Path Detection



The IR pair circuits are shown in the figure give below:

Fig 3.18 IR pair Circuit



The main features of this IR pair are:

Photo detector and preamplifier in one package

Internal filter for PCM frequency

Improved shielding against electrical field disturbance

TTL and CMOS compatibility

Output active low

Low power consumption

High immunity against ambient light

Continuous data transmission possible (up to 2400 bps)

Suitable burst length 10 cycles/burst

Table 3.11 Technical Specifications of IR pair

Characteristics DataSupply Voltage -0.3 to 6.0VOutput Voltage -0.3 to 6.0VJunction Temperature 100 ᵒcOperating Temperature -2.5 to 85ᵒcPower Consumption 50mWIrradiance 30W/m²Directivity ±45º



3.6.5 MAGNETIC SENSOR

Magnetic sensors or magnetic switches are electronic switches that close under the magnetic

field. In this AGV there are two magnetic sensors. XEN-1210 is the sensor used in this

design.

The XEN-1210is a CMOS linear magnetic field sensor with a very low offset. It uses

Xensor's patented high performance spinning-current Hall-plate technology, a precision

amplifier and a sigma delta AD converter, and offers full digital control and communication

through a SPI serial bus. The device does not need calibration and in contrast to low-offset

AMR sensors does not use a set/reset method. It has no hysteresis and is indestructible by

high magnetic fields. It does not need any external components and is truly a one-chip

solution.

These sensors are used for the purpose of position detection. It is used for detect the

loading and unloading station. The sensor is attached with the vehicle at two different

positions. Magnets are placed in such a way that one sensor close when the vehicle comes to

the loading station. And when that switch close lift operates and moves up. After loading the

vehicle moves along the path. When it reach the unloading station the next sensor close and

lift operates to move down.

The main features of this sensor are

Single axis magnetic measurement One chip solution 15nT resolution Wide magnetic field range (±63mT) No magnetic hysteresis Low voltage operation (2.5V to 3.3V) Single supply -40°C to 125°C Temperature Range



Fig 3.19 Magnetic sensor

It’s a glass capsule, inside the tube there are two reed blades, which is connected to the

voltage terminal. Reed blades are placed over lapped, but not connected. There is a contact

gap between the blades. And the tube is filled with inert gas.

Table 3.12 Technical Specifications of Magnetic sensorsSpecifications DataVDD 3.3VField Range ±63mTResolution(24 bits) 7.5nT/LSB

Hysteresis 10nTNoise 55nT/Hz^½Temperature range -40 to 125 ºC



3.6.6 DISPLAY UNIT It’s just to display the inputs and outputs of the system. It mainly displays the inputs of path

sensing IR sensors and working of the vehicle. Inputs are displayed using numbers.

JHD162A SERIES is the display unit used in the AGV.

Characteristics:Char. Dots 5 x 8Display content 16 CHAR x 2ROWDriving mode 1/16dAvailable types:TN STN (yellow green)Reflective with El or Led BacklightEL/100VAC 400HZLED/4.2VDC

Table 3.13 Technical Specifications of Display unit

Parameter DataSupply Voltage 5.0VInput High Voltage 2.2VOutput High Voltage 2.4VOperating Voltage 1.5mA

Table 3.14 Pin Configurations

Pin Connection1 Vss2 Vcc3 VEE

4 RS5 R/W6 E7 DB08 DB19 DB210 DB311 DB412 DB513 DB614 DB715 LED+16 LED-



Fig 3.20 Application Circuit of display unit



3.7 SOFTWARE COMPONENTS

We use ATmega328 microcontroller in this AGV. The microcontroller is the brain of the

vehicle. So the programming of the microcontroller has great imporantance in the working.

Arduino software is used to program the microcontroller. Program is burned using special

microcontroller board. For this ATmega328 microcontroller Arduino Uno board is used.

The Arduino Uno is a microcontroller board based on the ATmega328 . It has 14

digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a

16 MHz ceramic resonator, a USB connection, a power jack, an ICSP header, and a reset

button. It contains everything needed to support the microcontroller; simply connect it to a

computer with a USB cable or power it with a AC-to-DC adapter or battery to get started.

Arduino is an open-source electronics prototyping platform based on flexible, easy-to-

use hardware and software. It's intended for artists, designers, hobbyists, and anyone

interested in creating interactive objects or environments.

The program is written in the Arduino software using special commands. The main

feature of this software is that we can run the program before burning in to the

microcontroller. And we can check the function. It will helps to make changes in the

program, in easy way.

The program is written in such a way that when the vehicle is in on condition, the four

line detecting sensors works and detect the line. If the middle sensors close, the two driving

motor rotates. If left sensors close right motor works, if right sensors close left motor works.

If the object detector sensor closes, all the two motors stops whatever may be the line

detecting conditions.

When the right magnetic switch closes the third motor rotates in clockwise, when left

switch closes it rotates in anti clockwise direction. All the input signals for the line detection

and position detection are shown in the LCD display. Also the working status is shown in the

display



3.8 PROGRAM SOURCE CODE

#include <LiquidCrystal.h>

int a = 0;

int b = 0;

int c = 0;

int d = 0;

int e = 0;

int f = 0;

LiquidCrystal lcd(8, 9, 10, 11, 12, 13);

void setup()

{

Serial.begin(9600);

pinMode(A0, INPUT);

pinMode(A1, INPUT);

pinMode(A2, INPUT);

pinMode(A3, INPUT);

pinMode(A4, INPUT);

pinMode(A5, INPUT);

pinMode(7, OUTPUT);

pinMode(6, OUTPUT);

pinMode(5, OUTPUT);



pinMode(4, OUTPUT);

pinMode(2, OUTPUT);

pinMode(3, OUTPUT);

lcd.begin(16, 2);

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("L F Robot");

delay(1000);

}

void loop()

{

a = digitalRead(A5);

b = digitalRead(A4);

c = digitalRead(A3);

d = digitalRead(A2);

e = digitalRead(A1);

f = digitalRead(A0);


lcd.print("A:");


lcd.print(a);


lcd.print("B:");




lcd.print(b);


lcd.print("C:");


lcd.print(c);


lcd.print("D:");


lcd.print(d);

delay(100);

if((a==LOW && b==HIGH && c==HIGH && d==LOW) || (a==HIGH && b==LOW && c==LOW && d==HIGH))

{

lcd.clear();


lcd.print("Forward");

Serial.print("Forward\t");

digitalWrite(3, HIGH);



digitalWrite(6, LOW );



delay(200);



}

else if((a==LOW && b==LOW && c==HIGH && d== LOW ) || (a==HIGH && b==HIGH && c==LOW && d== HIGH ))

{

lcd.clear();


lcd.print("Left");

Serial.print("Left\t");







delay(200);

}

else if((a==LOW && b== HIGH && c==LOW && d==LOW) ||(a==HIGH && b==LOW && c==HIGH && d==HIGH))

{

lcd.clear();


lcd.print("Rihgt");

Serial.print("Rihgt\t");









delay(200);

}

else if((a==HIGH && b==HIGH && c==HIGH && d==HIGH )|| (a==LOW && b==LOW && c==LOW && d==LOW) )

{

lcd.clear();


lcd.print("Stop");

Serial.print("Stop\t");







delay(200);

}



if(f==HIGH)

{

while(1)

{

lcd.clear();


lcd.print("arm up");





digitalWrite(3, LOW);


delay(18000);





delay(200);

break;

}}

if(e==HIGH)



{

while(1)

{

lcd.clear();


lcd.print("arm down");






digitalWrite(2, LOW);

delay(18000);





delay(200);

break;

}}

delay(100);

}



CHAPTER IV

DEVELOPED PROTOTYPE

4.1 STRUCTURE

The vehicle is designed in such a way that, have stability during loading and working. The

lifting parts are provided in the front position. It comes above the front globe tyre. The

electronic and electrical parts are situated the rest of surface. Motor for driving are provided

in the rear region. Hence during dynamic loading the vehicle will be stable.

The structure of the vehicle is shown in the figure,



Fig 4.1 Front view of AGV

Fig 4.2 Top view of AGV



4.2 SENSORS POSITIONS

The positions of sensors are important factor to detect the position. The sensors for detecting

the path are situated after the front wheel. But the obstruction detection sensor is placed

below the chassis, and in front of the front tyre. There are four IR sensors used to detect the

path. They are along a line parallel to the breadth. And side sensors are placed at an equal

distances from middle sensors.

The width of the white line is little more than the distance between two sensors. All

the four sensors were give different movements during different combination. The

combination means closing of IR sensors. According to it the working of the driving motors

change. Initially the AGV is placed above the line, in such a way that the two middle sensor

comes above the white line.

During the straight path the middle sensors close, the two motors run in forward

direction with equal speed. Thus the vehicle moves in the straight line. When two of the left

side close left motor stops and right works. Then the AGV takes a left turn depending upon

the curvature. And when two right side sensors close,right side motor stops and the left

works. Thus the AGV takes a right turn.



Fig 4.3 IR Sensors positions of AGV

The design of path is very important for an AGV. The magnetic sensors are placed below the

driving motors. Two magnets are used to detect the loading and unloading station. There is a

particular distance between those sensors and the lift. The loading stand should be placed

about at that distance from the magnet. Lifting up sensor is placed below the right motor. So

one of the magnet is placed in the right side of the path. Lifting stand is placed about a

distance from that magnet. The magnets are placed in such a way that any one of its poles

comes to top. Only then the magnetic switch works.


IR Sensors (Path Detection)

Obstruction Detection


Fig 4.4 Magnetic sensors positions

4.3 FLOW CHART


Bottom View

Magnetic sensor for detecting loading station

Magnetic sensor for detecting unloading station

12


Fig 4.5 Flow chart


Start

Path detection stops

Path detector detects

Forward, right or left turn

Vehicle stops

If object detection

sensor

Magnetic sensor

Lift works

DetectNot Detect

OnOff


4.4 BLOCK DIAGRAM

Fig 4.6 Block Diagram

Block diagram is a diagram of a system, in which the principal parts or functions are

represented by blocks connected by lines that show the relationships of the blocks. They are

heavily used in the engineering world in hardware design, electronic design, software design,

and process flow diagrams. In this diagram direction of all arrows are either from or to the

microcontroller.


MICRO-

CONTROLLER

LCD

MOTOR 1

POWER SUPPLY

MOTOR

DRIVER

MOTOR 2

MAGNETC REED SENSOR

LINE DETECTOR SENSOR

MOTOR

DRIVERMOTOR 3

OBJECT DETECTOR SENSOR

http://en.wikipedia.org/wiki/Process_flow_diagram

http://en.wikipedia.org/wiki/Software_design

http://en.wikipedia.org/wiki/Electronic_design

http://en.wikipedia.org/wiki/Hardware_architecture

http://en.wikipedia.org/wiki/System

http://en.wikipedia.org/wiki/Diagram


4.5 CIRCUIT DIAGRAM

Fig 4.7 Circuit Diagram



The fully fabricated prototype of Automatic Guided Vehicle has possessed the intelligences

such as following a particular line, loading and unloading at particular stations and collision

avoidance etc.

Fig 4.8 Fully Developed Prototype



4.6 THEORETICAL AND LOGICAL CALCULATIONS

Torque of DC motor used, T = 12Kg-cm

= 1.1772 N-m

Speed of motor, N = 100 RPM

Angular Velocity, ω = 2ΠN/60

= (2*Π*100)/60

= 10.47 rad/sec

Physically Power is the rate of doing work. For linear motion, power is the product of force multiplied by the distance per unit time. In the case rotational motion, the analogous calculation for power is the product of Torque multiplied by the rotational distance per unit time

Rotational Power, P = T * ω

= 1.1772*10.42

=12.33 W

No. of motors available for driving mechanism = 2 motors

So total power available for driving = 2* 12.33

= 24.66 W

There is only one motor is used for the lifting purposes,

So maximum power available at lifting mechanism = 12.33 W



We have relation, v = r*ω

Where, v= Linear velocity

R= Radius

ω= Angular velocity

Diameter of shaft, d= 0.6cm

Radius of shaft, r= 0.3cm

=0.3*10^ (-2)

∴ Linear velocity, v = (0.3*10^ (-2)) * 10.47

= 0.03141 m/s

= 3.14 cm/s

Weight of carrier = 1.495 Kg

Width of line marking= 4.3cm

For Lifting section,

Shaft Torque, Tsh = output/2ΠN

= 1.1772/ (2Π*100)

= 1.8735* 10^ (-3) N-m

Force * Distance = Torque

Distance to be lifted, l= 5mm

Force * (5*10^ (-3)) = 1.8735*10^ (-3)

Force, F = 3.75 N



Force, F= Load * g

Acceleration due to gravity, g= 9.81m/s2

Load = 3.75/9.81

= 0.383 Kg

≈400 gms



4.7 BILLING

NO ITEM NO. ITEM COST/ITEM TOTAL COST,(R.S)

1 DC Motor 3 200 600

2 Micro Controller 1 350 350

3 Driver IC 2 100 200

4 LCD Display 1 350 350

5 IR Sensors 5 175 875

6 Magnetic Switch 2 80 160

7 Acrylic Sheet 1 160 160

8 Aluminum channel 1 30 30

9 Battery 1 400 400

10 Fasteners 25 25

11 Magnets 3 25 75

12 Sticking Glues 2 30 60

13 Electronic Components 250

14 Arduino board 1 1350 1350

Total 4885

Table 4.1 Billing Table



CHAPTER V

CONCLUSION

The AGV is a productivity increasing feature in a factory. During the manufacturing of this

AGV we had found many of intelligence that can be given to it. We provide the basic

functions like line following and collision avoiding. And the main function, transportation of

goods from station to station. The followings are the main features of the prototype which we

fabricated.

1. Speed of delivery

2. Adjustment of vehicle speed

3. Flexibility of path

4. Adaptive to changes in factory layouts

5. Avoid collision with other objects

6. Reduction in labour cost

7. Reduction in running cost compared to conveyer systems

8. Ability to add sensors to detect the payload conditions

9. Ability to adjust the lifting time

10. Continues cycle of working

11. Conditions for line following can be change easily

Automatic Guided Vehicle can be used in a wide variety of applications to transport

many different types of material including pallets, rolls, racks, carts, and containers. AGVs

excel in applications with the following characteristics:

Repetitive movement of material over a distance

Regular delivery of stable loads

Medium throughput/volume

When on time delivery is critical and late deliveries are causing inefficiencies

Operation with at least two shifts

Archive Systems

Cross Docking

Distribution

High Density Storage



High Speed Sortation

Material Flow and Transport

Production and Manufacturing Delivery Systems

Production and Manufacturing Support Systems

Warehouse Management and Control

Work-In-Process Buffers

The fabricated models have following advantages while comparing with the existing

models of this kind. The analyzing of advantages helps to motivate the fabrication of

AGV in the manufacturing industries. The important advantages of the prototype are

given below

Reduce manpower

Increase productivity

Eliminate unwanted fork trucks

Reduce product damages

Maintain better control of material management

Traffic control is not needed in this system because of single carrier

Suitable to transfer frames

Each of the machines has their own merits and demerits. During the production we

had faced many problems. Much of them were solved during the assembling. But still

some of them stand here, which can’t have to remove. The followings are the

limitations of the prototype fabricated:

Installation cost is very high.

AGVs are fragile and should be handled with care.

Regular care, inspection and maintenance needed

Should be recharged periodically

AGV will stop delivery when it is forced off the path.

Battery should be recharged during intervals.

Sun light affect the movement.



REFERENCES

www.elsevier.com/locate/ejor/Survey of research in the design and control

of automated guided vehicle systems

www.jbtcorporation.com/en/Solutions/Automatic-Guided-Vehicles

http://www.arduino.cc/

www.atmel.com/devices/atmega328

www.sunroms.com

Automation, Production Systems, And Computer Integrated Manufacturing, By Groover,

Mikell.P, ISBN 8120334183


http://www.sunroms.com/

http://www.atmel.com/devices/atmega328

http://www.arduino.cc/

http://www.jbtcorporation.com/en/Solutions/Automatic-Guided-Vehicles

Automated Guided Vehicle

Documents

Transcript of Automated Guided Vehicle