A Project report on

UN-MANNED ARMY WAR TANKER WITH AUTOMATIC SELF

DEFENDING AND ATTACKING SYSTEM

BACHELOR OF TECHNOLOGY

in

MECHANICAL ENGINEERING

Submitted By

SUSHANG SHAH - 105D1A03A4

Under the Guidance of

Mr. D. MADHAVA REDDY

Associate professor

Department of Mechanical Engineering,

KASIREDDY NARAYANREDDY COLLEGE OF ENGINEERING &

RESEARCH

Affiliated to Jawaharlal Nehru Technological University.

2010 – 2014

ACKNOWLEDGEMENT A project work on this magnitude is not possible without the help of several

people. It is with immense satisfaction that I present our practical experience in the form

of a project carried out in ARUNODAYA ELECTRO POWER TECHNOLOGIES

PVT. LTD

It is with a feeling of great pleasure that I would like to express my most sincere

heartfelt gratitude to Mr. D. MADHAVA REDDY(Associate professor) KNRR,

Hyderabad for suggesting the topic for my thesis report and for his ready and able

guidance throughout the course of my preparing the report. I am greatly indebted to him

for his constructive suggestions and criticism from time to time during the course of

progress of my work.

I express my sincere thanks to Mr. S. AMARESH BABU, principal & Mr. D.

MADHAVA REDDY, Head of Department of Mechanical Engineering, KNRR,

Hyderabad.

I am thankful to teaching and non teaching faculty members of the mechanical

engineering department who helped directly or indirectly in successful completion of the

project.

I am very grateful to my family and friends for their constant support and

encouragement during the project period.

SUSHANG SHAH - 105D1A03A4

CONTENTS

Abstract IV

List of figures VI

List of tables VII

1. INTRODUCTION 01 - 12

1.1 Potential of unmanned warfare 02

1.2 Need for unmanned 02

1.3 Unmanned ground vehicles (UGV) 03

1.3.1 Tele-operated UGV

1.3.2 Autonomous UGV

1.4 Land theatre unmanned warfare 05

1.5 Unmanned warfare in the air 07

1.5.1 Non Lethal UAV

1.5.2 Lethal UAV

1.6 Naval unmanned warfare 10

1.7 Technology for the development

of unmanned systems 11

2. WAR TANKER 13 - 16

2.1 Light Tanks 14

2.3 Heavy Tanks 14

2.3 History 15

3. FUNCTIONAL DESCRIPTION 17 – 38

3.1 Remote Control Unit 17

3.2 Mechanical actuation system 20

3.3 Gear drive 22

3.4 DC motors 24

3.5 H-bridge 27

3.6 Limit switches 31

3.7 UM 3562 (Gun sounds generator) 32

3.8 Relay 34

3.9 Automatic mode 37

3.10 Power source 37

4. MICROCONTROLLERS 39 - 52

4.1 Introduction 39

4.2 Necessity of microcontroller 39

4.3 Advantages of microcontroller 40

4.4 AT89C51 type microcontroller 41

4.5 Features of 8051 architecture 42

4.6 Pin diagrams 43

4.7 Point 3 pins alternate function 44

4.8 Types of memory 46

4.8.1 Code memory

4.8.2 Internal Ram

4.9 Special function registered memory 47

4.10 Interrupts 54

5. SOFTWARE DETAILS 55 - 56

5.1 Keil’s Software 55

5.2 Simulation 55

5.3 Use of software for execution of microcontroller program 55

5.4 Problems faced by embedded program developers 56

6. SCOPE OF DEVELOPEMENT 57 – 59

6.1 Limitations 58

6.2 Future scope 58

Conclusion 60

References 61

CHAPTER – 1

INTRODUCTION

Manpower scarcity has been a perennial problem for many armed forces around

the world. Over the years, there has been a decline in the absolute numerical make-up of

these organizations, which, if not managed properly, can affect their operational

capabilities. This scarcity is a situation that is unlikely to improve in the foreseeable

future, given the current low birth rates and conflicting demands for manpower.

From a numerical perspective, this constraint means that the armed forces cannot

mass together the sheer number of ground troops as before. From a risk perspective,

every soldier on the battlefield is now a precious resource which should not be exposed to

unnecessary risks. This translates into further constraints for battle planners, who may not

have the leeway to select the riskier but more expedient military options. Finally, from

the skills perspective, smaller population bases make it difficult to find, select, train and

develop specialized combatant resources like pilots and submariners.

Thus, it is crucial that new avenues be explored to circumvent this prevalent trend

of manpower shortages. One viable solution lies in exploiting technology and pushing the

limits of force multipliers. Within the domain of force multipliers, there lies a relatively

new discipline, unmanned warfare.

The definition of 'unmanned' chosen for this article is fairly loose, as the emphasis

is not solely on taking men out of machines but also on how to employ technology to

make better use of its manpower. Thus, while the focus is on unmanned warfare in its

literal sense, the article will also touch on some equipment or systems which result in

lower manpower usage (or higher operational capability with the same manning). In

doing so, please accept that some aspects of this article border on technological

innovation as opposed to unmanned warfare per se.

1.1 Potential of unmanned warfare :

Unmanned warfare is a relatively new approach in the conduct of warfare, where

the boundaries are not well charted and limited largely by our imaginations. Unmanned

warfare will not only help overcome manpower and resource constraints but will also

enhance operational capabilities, since it can now move into areas where mankind has

previously feared to tread. With unmanned warfare, the competitive advantage can be

swung such that human numerical superiority is no longer an overwhelming advantage or

a pre-requisite for victory.

1.2 Need for unmanned :

The impetus to go unmanned include optimizing the deployment of manpower,

enhancing operational capabilities and being able to venture into territory once out-of-

bounds to mankind (e.g. deep ocean, space, etc). In particular, unmanned systems should

be used to replace humans where the work is dangerous, dirty or dull.

Some specific advantages in going unmanned include:

Reduction in manpower requirement: Developments in unmanned technology

now enables machines to perform tasks once undertaken by operators with equal

if not better precision. This direct substitution of manpower will lead to a

corresponding reduction in manpower needs.

Overcome fatigue and human error: Machines do not tire out as easily as men.

Operations that require constant alert or repetitive work over long durations are

thus potential areas where unmanned warfare can be profitably employed.

Minimize hazards: Risks to humans can be reduced as unmanned systems can

take over hazardous jobs previously done by human beings.

Cost savings: Besides manpower savings, there are also cost reductions in the

form of human cost (life) savings, training cost savings or even system cost

savings as new unmanned systems can enhance work flow and improve general

work cycles.

Maximum ammo loading : Since this tanker have no human interference the

space which is leftover can be used to load more ammo, which provides more

durability in the warfare.

Decision making: Although unmanned systems are becoming increasingly

sophisticated and 'intelligent', it is still difficult to entrust machines with

subjective decision making. We must avoid careless delegation of responsibilities

to technology that perform only under programmed patterns.

Unmanned Ground Vehicles (UGV) save lives and improve national defense capabilities

by providing agencies of the Department of Defense (DOD) with the control system architectures,

advanced sensor systems, research services, and standards to achieve autonomous mobility for

unmanned ground vehicles.

1.3 Unmanned Ground Vehicles (UGV)

UGV are robotic platforms that are used as an extension of human capability. This

type of robot is generally capable of operating outdoors and over a wide variety of

terrain, functioning in place of humans.

UGVs have counterparts in aerial warfare (unmanned aerial vehicle) and naval

warfare (remotely operated underwater vehicles). Unmanned robotics is actively being

developed for both civilian and military use to perform dull, dirty, and dangerous

activities. Some UGVs are employed in War in Iraq.

Fig 1.1 UGVs Prototype

There are two general classes of unmanned ground vehicles:

1. Tele-operated ones and

2. Autonomous ones.

An unmanned ground combat vehicle (UGCV) is an autonomous, all terrain

unmanned ground vehicle designed for combat.

1.3.1 Tele-operated UGV:

A tele-operated UGV is a vehicle that is controlled by a human operator at a

remote location via a communications link. All cognitive processes are provided by the

operator based upon sensory feedback from either line-of-sight visual observation or

remote sensory input such as video cameras. A basic example of the principles of tele-

operation would be a toy remote control car. Each of the vehicles is unmanned and

controlled at a distance via a wired or wireless connection while the user provides all

control based upon observed performance of the vehicle.

There are a wide variety of tele-operated UGVs in use today. Predominantly these

vehicles are used to replace humans in hazardous situations. Examples are warfare,

explosives and bomb disabling vehicles.

1.3.2 Autonomous UGV:

An autonomous UGV is essentially an autonomous robot but is specifically a

vehicle that operates on the surface of the ground.

A fully autonomous robot in the real world has the ability to:

Gain information about the environment.

Work for extended durations without human intervention.

Travel from point A to point B, without human navigation assistance.

Avoid situations that are harmful to people, property or itself, unless those are part of its

design specifications

Repair itself without outside assistance.

Detect objects of interest such as people and vehicles.

A robot may also be able to learn autonomously. Autonomous learning includes

the ability to:

Learn or gain new capabilities without outside assistance.

Adjust strategies based on the surroundings.

Adapt to surroundings without outside assistance.

Autonomous robots still require regular maintenance, as with all machines.

1.4 Land unmanned warfare :

The land theatre has traditionally been the largest employers of manpower. With

reducing manpower and increasing battlefield risks, technology is no longer regarded as

just a force multiplier, but rather one that would produce a paradigm shift in war fighting.

Manpower requirements can be dramatically reduced in the battlefield with

unmanned platforms. UGVs, coupled with appropriate sensors, are able to give

commanders a bird's eye view of the battlefield, without having to incur risks to himself,

observers or pilots. Such a view has obvious benefits - to the intelligence community, to

manoeuvre commanders and to targeting agencies. UGVs can also be employed as rebro

or electronic warfare platforms. In the longer term, armed UGVs may well become

operationally and economically viable, thus enabling them to perform tactical attack

roles.

Tactical Unmanned Ground Vehicles (TUGV), the ground equivalent of UGVs,

are able to perform some of the roles currently done by UAVs. Equipped with weaponry

or sensors, they could complement or even replace some of the roles assumed by scouts

and signalers. In these roles, one edge of the TUGV over the UAV is its staying power

and ability to hold ground. TUGV is also able to breach and open minefields/ obstacles

and clear axes for armor and logistics re-supply.

Unmanned Ground Sensors (UGS) are a cost effective replacement for manned

systems that have previously been used for monitoring or for communications. They can,

for example, be deployed by helicopters or C-130 to critical points to detect time critical

mobile targets (i.e. maneuver forces, tank columns). They can also be used as signals

nodes to serve as communication relay platforms, thus relieving signals personnel from

performing a tedious and time consuming job.

Dramatic breakthrough in robotics and tele-operated mine breaching can greatly

reduce the labor-intensive nature of mine-clearing. Also, development of new mine

detection technology now permits untrained troopers, using devices which incorporate

thermal imaging and ground penetrating radar, to be able to detect metallic and non-

metallic mines. This reduces the dependence on specialized combat engineers and

simultaneously increases operational capability through speedy mine detection.

There are a few additional unmanned systems that are a long way from seeing

operational employment, but which are worth mentioning in view of their long term

potential. For example, developments in unmanned technology include robots that can

undertake dangerous and dirty work. The US military has been pursuing the concept of

'Pointman' for some time. Pointman is a light-weight, sensor-laden, armed robot used to

reconnoiter buildings, bunkers and tunnels, in order to detect booby traps, explosives and

the enemy. It will be able to climb stairs, operate in all weather and light conditions, and

is expected to be especially useful in what the US Army terms 'operations other than war'.

Still looking at longer term developments, armor units may one day field

remotely-controlled tanks. One of the modes of employment is to have one manned tank

control and operate two unmanned, remote-controlled tanks. Navigation and targeting

inputs provided by the tank commander are utilized by the remote-controlled tanks to

acquire and destroy targets. The firepower of armor units can hence be enhanced

tremendously with fewer or similar numbers of tank crews.

Remotely-controlled self-propelled guns or howitzers could operate together with

manned guns using the same concept as the remote controlled tanks. This concept seems

closer to fruition than unmanned tanks, as the technological challenges appear less

daunting. The need for human judgment in each individual fighting unit also appears less

critical.

1.5 Unmanned warfare in air:

Plagued with constraints of limited human resources and a sizable reduction in the

pool of youths who fulfill stringent recruitment requirements, air forces around the world

will be compelled to explore means to maintain or extend their operational capabilities

with an increasingly trim fighting force.

The employment of unmanned platforms in the modern battlefield serves to

alleviate problems caused by the shortage in manpower and resources. In employing

unmanned platforms, pilots may also be removed from aircraft penetrating defended

enemy airspace, thus reducing the danger arising from exposure to hostile fire.

The benefits are immediately obvious. First, human attrition will be reduced.

Second, the aircrew whose functions are now assumed by unmanned platforms can be

channeled to other crucial functions like air defense, C31 and transportation missions.

Finally, planners will be able to undertake more risky but decisive combat missions, such

as SEAD, without exposing aircrew to excessive risk.

UAVs can broadly be characterized as lethal and non-lethal systems. As its name

suggests, non-lethal UAVs refers to the class of UAVs used for reconnaissance,

surveillance, relay, target designation, ECM, SIGINT, ELINT, radar decoy and

meteorological surveillance. Lethal UAVs, of course, refer to the class of UAVs which

inflicts physical damage to enemy assets or installations operations.

Fig. 1.2 MQ-9 reaper

Land based UAVs should augment the manned Maritime Patrol Aircraft (MPA)

so that round the clock surveillance and intelligence collection can be achieved. These

UAVs would be especially useful at the beginning of war when naval warships have to be

deployed beyond NADA controlled areas. The UAVs will remove the need to send

manned MPAs to unprotected airspace, thus reducing the risk to the aircraft and its crew.

1.5.1 Non-Lethal UAVs

Many non-lethal UAV roles have become well-established in many armed forces.

Reconnaissance UAVs are widely used to map the enemy's defense locations, practices,

electronic profiles and vulnerabilities. As their endurance and payload improve, these

UAVs can take on the more demanding surveillance and airborne early warning functions

as well. EW UAVs are capable of using chaff and ECM to degrade the enemy's radar or

communications.

Used together with anti-radiation missiles or drones, these EW UAVs can

effectively shut down the enemy's radar operations. In SEAD) operations, UAVs can be

deployed as decoys to entice the defenders to turn on their radars or fire their missiles at

the wrong targets. Manned strikers following behind the UAVs can then move in to

complete their missions with relative ease.

1.5.2 Lethal UAVs

Lethal UAVs can best be looked at by dividing them into two distinct categories:

counter-air and strike. I will examine these two components separately and assess the

viability of UAVs to replace manned aircraft during wartime.

Air-to-air combat is very dynamic and dependent upon the pilot's judgment and

skill to outwit and out-manoeuver the aggressor so as to get into an advantageous position

for the kill. This applies even when an aircraft is armed with the most advanced AAMs,

especially if the enemy is similarly equipped. Furthermore, in an air battle, the air picture

is usually a complex one, with many real-time injects like weather, use of ECM or

ECCM, changes in tactics, attention, etc. The pilots, with the help of GCI, will have to

make impromptu, split- second decisions to circumvent the friction of war.

The use of UAV’s as interceptors will expose one of its biggest shortcomings; its

lack of decision making abilities. However advanced the UAV, it is still unable to replace

the pilot in a dog-fight. The situational awareness is just not the same. More often than

not, UAVs are very scenario dependent and operate well only in a predictable

environment. The lack of a human on board limits a UAV to perform mostly pre-

programmed standard functions.

Although UAVs cannot replace manned fighters in air-to-air combat, they can be

used as decoys to reduce friendly losses. Decoys can be scrambled together with manned

interceptors to complicate the enemy's air picture, distracting their pilots or causing them

to expend their missiles on the decoys.

Strike missions are a hazardous task as the strike aircraft are susceptible to many

threats: enemy fighters, SAMs, AAA etc. A typical strike mission would involve a lot of

resources. Besides the strikers, sweepers are to fly ahead and clear the path for their

transit. In addition, to have accompanying escort fighters are needed to eliminate hostile

aircraft that slip through to threaten the strike aircraft.

UAVs can be used to reduce the heavy demands and risks of strike missions.

Many strike aircraft and bombers follow a pre-determined route into enemy territory and

strike specific targets on the ground. The predictable nature of this task makes it suitable

for UAV execution. Technically, the cruise missile is a small, disposable UAV. These

missiles are cost-effective, proven in war, and do not need escorts or sweepers. Re-usable

bomber UAVs are also under development, but these are probably less flexible and

effective than missiles as they would require a great deal more support for them to fulfill

their role.

A final benefit of using UAVs is that they are less dependent on runways. Most

unmanned platforms are easier to store and deploy than fixed wing aircraft, and many do

not need a long runway to launch from. Of particular significance, land or sea launched

cruise missiles would allow an armed force to retain a long-range strike capability even if

its runways were closed and its aircraft temporarily grounded.

1.6 Naval unmanned warfare :

Unmanned platforms are relatively new naval forces. Naval forces should

consider adopting more unmanned systems in the naval theatre, with manned warships

deployed as a controlling force or a follow-up strike force when a high casualty rate has

been inflicted on the opposing force.

They are the Unmanned Aerial Vehicle (UAV), Unmanned Undersea Vehicle

(UUV) and Sound Ocean Surveillance System (SOSUS). The following discusses the

ways these platforms can replace or supplement a navy's manned platforms and improve

its operational effectiveness.

Navies should acquire a mix of ground based and sea launched UAVs. Complete

surveillance packages configured for tactical surveillance should be available in the sea

launched version. Real time data-linked, probably through satellite communications,

should be the main command and control requirement so that commanders ashore and at

sea are able assess the reconnaissance picture. High adaptability to mission changes and

reassignment should also be essential features of the vehicle.

Sea-launched UAVs would by necessity, be lighter and have less endurance than

their land based counterparts. However, they have an important role in that they provide

flexibility and autonomy to the commanders at sea, who can then solve immediate

tactical surveillance problems without assistance from shore.

For littoral warfare, UAVs should be able to solve some of the problems when

ships operate in proximity to land. When warships operate in hostile coastal waters, the

risk is invariantly higher as they are subjected to threat from ashore and ambushing

enemy military or para-military craft. Surveillance pictures provided by UAVs would

finish task group commanders with valuable early warning of enemy presence.

Clearance of island groups by warships is another challenging task. In this case, a

naval force should further exploit unmanned technology by acquiring remote controlled

arsenal craft equipped with short to medium range high discrimination missiles to engage

hostile craft detected by the UAV.

In the area of naval gun fire support, UAVs can provide spotting and eventually

Target Damage Assessment to the Shore Bombardment Commander.

1.6.1 Undersea Vehicles :

The application of unmanned vehicles for underwater warfare is predominantly in

the area of mine clearance. Mine clearance in hostile waters can be fulfilled with the Self-

propelled Acoustic and Magnetic Minesweeping System (SAMMS). This unmanned,

remotely controlled mine sweeping craft is capable of establishing a safe route through

mined waters.

Navies could consider acquiring a passive mine clearance capability so as to

expand their mine-sweeping versatility. The US Navy is currently developing a tactical

scale Unmanned Undersea Vehicle (UUV) to conduct covert, fully autonomous, long

duration mine warfare and tactical oceanography in littoral waters. To date, the UUV has

demonstrated a navigational accuracy of 0.18% of distance traveled. Such a vehicle

allows naval forces to conduct covert mine clearance and seabed surveys during POT

when aggressive counter-mine measures could not be conducted. Another advantage of

the UUV is that it can be launched covertly from a submarine.

1.6.2 Anti-Submarine Warfare :

Manned assets are still largely used in the area of Anti-Submarine Warfare, as it

remains the playground for tacticians. However, SOSUS can be used to monitor

submarine movements at various key points in our area of operations. This will reduce

the demands on manned anti-submarine warfare assets. With further development in

UAVs, ASW packages can also be fitted onboard to provide an extended arm to airborne

ASW.

1.7 Technology for the development of unmanned systems :

Competition to dominate the battlefield of the future is competition to create,

adopt and dominate emerging technologies. In the area of unmanned warfare, getting

ahead requires:

a. A keen understanding of how future battles would be fought and how unmanned

warfare fits in.

b. A developmental process for exploring, assimilating and exploiting current and

emerging future technologies applicable in unmanned systems.

The unmanned warfare paradigm may be defined in three dimensions. Service

groups broadly describe the various services in the Armed Forces, or who is being

satisfied. Service functionalities describe service needs, or what is being satisfied.

Technologies describe the way, or how the service group’s needs are satisfied. The who

and what, having already been discussed, we can see that the how may be classified into

three main areas of required technologies. These are:

a. Sensory: This is predominantly in the departments of sight & sound (e.g. to detect the

enemy), touch (e.g. to ascertain reality) and smell (e.g. to determine toxicity of air).

b. Mechatronics: This entails the delivery systems upon which the unmanned systems

would ride on. It would include technologies such as propulsion, aerodynamics and

robotics.

Through a systematic and rigorous program of developing this unmanned

capability, new core competencies would emerge and these are potential highways to the

future for our local defense industry. Besides providing a country's armed forces with a

military advantage, technologies applied in unmanned systems have potential for a

myriad of commercial payoffs. For instance, car manufacturers are beginning to explore

unmanned driving on highways for safety as well as time and highway efficiency. Hence,

unmanned technology offers our defense industry an attractive area to venture into, with

additional potential for commercial payoffs.

CHAPTER – 2

WAR TANKERS

WAR TANKER :

A tank is a tracked, armored fighting vehicle designed for front-line combat

which combines operational mobility and tactical offensive and defensive capabilities.

Firepower is normally provided by a large-caliber main gun in a rotating turret and

secondary machine guns, while heavy armor and all-terrain mobility provide protection

for the tank and its crew, allowing it to perform all primary tasks required of armored

troops on the battlefield.

Fig 2.1 Parts of a war tanker

The tank remains the “King of the battle field” having come into its own during

world war 1. Designed initially to navigate the miles of trenches and obstacles along the

western front, the tank ( then known as the “Landship”) was first envisioned in an

infantry support role. The first tank-versus-tank battle took place in the war between

british and german tanks with results being rather anticlimatic. As

experience bagan to dedicate function, the tank was later user to spearhead

critical alied offensives in breaking down enemy positions and causing general havoc. In

the end, the armored vehicle became a permanent fixture of the battlefield – evolvinginto

the spearhed of any successful land campagin to date.

World War 1 saw the origins of the "Landship", which became the "tank" as

we know it - all thanks to British engineering out of Bovington, England.

World War 1 proved a testing ground concerning aspects related to modern

warfare. Poison gas, the flamethrower, the aircraft (as a fighter, light bomber and heavy

bomber), the machine gun and the "tank" were all born in their practical sense in during

the dark days of The Great War. Early "tanks", known then as "landships" after their sea-

going battleship counterparts, were largely pioneered by the British Navy and began life

as awkward rhomboidal-shaped steel beasts with side-mounted cannon and machine gun

armament. Such armored vehicles helped to break the stalemate along the Western Front

for the Allies and force the Armistice of November 1918. By the end of the war, the

revolutionary French Renault FT-17 Light Tank was in use and it brought about the

revolving turret that proved a common feature in all future tank developments since.

Today's massive and powerful war machines can all trace their roots back to these early

ground-breaking initiatives.

2.1 Light tanks :

Light tanks continued to be built, but for very limited roles such as amphibious

reconnaissance, support of Airborne units, and in rapid intervention forces which were

not expected to face enemy tanks. The Soviet PT-76 is a good example of a specialized

light tank. It is amphibious and has the firepower to kill other reconnaissance vehicles,

but it is very lightly armored. The US M551 Sheridan had similar strengths

and weaknesses, but could also be airdropped, either by parachute or

LAPES.

2.2 Heavy tanks :

Heavy tanks continued to be developed and fielded along with medium tanks until

the 1960s and 1970s, when the development of anti-tank guided missiles and powerful

tank guns rendered them ineffective in their role. The combination of large HEAT

warheads, with a long effective range relative to a tank gun, and with high accuracy

meant that heavy tanks could no longer function in the stand-off, or overwatch role.

Much cheaper antitank guided missiles could fill this role just as well. Medium tanks

were just as vulnerable to the new missiles, but could be fielded in greater

numbers and had higher battlefield mobility. Furthermore, the value of light tanks for

scouting was diminished greatly by helicopters, although many light tanks continued to

be fielded.

2.3 History :

The tank is the 20th century realization of an ancient concept: that of

providing troops with mobile protection and firepower. The internal

combustion engine, armor plate, and the continuous track were key

innovations leading to the invention of the modern tank.

Armored trains appeared in the mid-19th century, and various

armored steam- and petrol engines vehicles were also proposed. The first

armored car was produced in Austria in 1904. However, all were restricted

to rails or reasonably passable terrain. It was the development of a practical

caterpillar track that provided the necessary independent, all-terrain

mobility.

Many sources imply that Leonardo da Vinci and H.G. Wells in some way foresaw

or "invented" the tank. Da Vinci's late 15th century drawings of what some describe as a

"tank" show a man-powered, wheeled vehicle with cannons all around it. However the

human crew would not have enough power to move it over larger distance, and usage of

animals was problematic in a space so confined.

The machines described in Wells's 1903 short story The Land Ironclads are a step

closer, in being armor-plated, having an internal power plant, and being able to cross

trenches. Some aspects of the story foresee the tactical use and impact of the tanks that

later came into being. However, Wells's vehicles were driven by steam and moved on

Pedrail wheels, technologies that were already outdated at the time of writing. After

seeing British tanks in 1916, Wells denied having "invented" them, writing, "Yet let me

state at once that I was not their prime originator. I took up an idea, manipulated it

slightly, and handed it on." It is, though, possible that one of the British tank pioneers,

Ernest Swinton, was subconsciously or otherwise influenced by Wells's tale.

The "caterpillar" track arose from attempts to improve the mobility of wheeled

vehicles by spreading their weight, reducing ground pressure, and increasing their

adhesive friction. Experiments can be traced back as far as the 17th century, and by the

late nineteenth they existed in various recognizable and practical forms in several

countries.

It is frequently claimed that Richard Lovell Edgeworth created a caterpillar track.

It is true that in 1770 he patented a "machine, that should carry and lay down its own

road", but this was Edgeworth's choice of words. His own account in his autobiography is

of a horse-drawn wooden carriage on eight retractable legs, capable of lifting itself over

high walls. The description bears no similarity to a caterpillar track.

The first

combinations of the three principal components of the Tank appeared in the decade

before World War One. In 1903, a Captain Levavasseur of the French Artillery proposed

mounting a field gun in an armored box on tracks. Major W.E. Donohue, of the British

Army's Mechanical Transport Committee, suggested fixing a gun and armored shield on

a British type of track-driven vehicle. In 1911, a Lieutenant Engineer in the Austrian

Army, Günther Burstyn, presented to the Austrian and Prussian War Ministries plans for

a light, three-man tank with a gun in a revolving turret. In the same year an Australian

civil engineer named Lancelot de Mole submitted a basic design for a tracked, armored

vehicle to the British War Office. In Russia, Vasiliy Mendeleev designed a tracked

vehicle containing a large naval gun.

All of these ideas were rejected and, by 1914, forgotten, although it was officially

acknowledged after the War that de Mole's design was at least the equal of the tanks that

were later produced by Great Britain, and he was voted a cash payment for his

contribution. Various individuals continued to contemplate the use of tracked vehicles for

military applications, but by the outbreak of the War no one in a position of responsibility

in any army had any thoughts about tanks.

CHAPTER – 3

FUNCTIONAL DESCRIPTION

The functional description and working operation as per the block diagram is

explained below. The block diagram and the circuit diagram are provided in the next

chapter.

As mentioned in the introduction the unmanned vehicles are either operated

autonomously or through tele-communications i.e., remote. The robot (war tanker)

designed here is the remote operated one. Through this remote the robot can be controlled

sitting at a safe place. The remote is designed with eleven control keys, micro-controller

(89C2051) and the zigbee transmitter (Tarang). Out of these eleven keys, four keys are

used to control the vehicle’s direction i.e., to operate the in forward, backward, right and

left directions. Two keys are to rotate the gun on the tank in clockwise and anti-clockwise

directions. Two keys are used to set the tanker in automatic or manual mode of operation.

Two keys are used for the gun to lift up and down in vertical direction and one key is

used to start firing from the gun.

When automatic mode of operation is selected, the vehicle movement will only be

controlled where as gun firing will be done automatically depending on the target hit

direction. But in manual operation, everything is to be controlled through the remote

itself.

3.1 Remote control unit :

The remote control unit is nothing but the transmitter unit through which the

tanker is controlled. The main components present in this unit are the push buttons, micro

controller (89C2051), Zigbee transmitter and a battery to provide power supply to all

these components. As mentioned earlier, a total of eleven keys (push buttons) are used to

control the vehicle and these are interfaced with the 89C2051 micro controller.

Depending on the key pressed, the controller generates a unique 8 bit binary code which

is fed to the Zigbee transmitter for modulation. The detailed explanation about the Zigbee

Tarang module is provided below.

The data-transmitting unit (hand held Equipment) including 89C2051

microcontroller designed to operate at 5V DC, and the battery used in the card is 9V

pack, therefore with the help of a voltage regulator of 7805, constant supply of +5V is

derived. Supply to the circuit is provided through the ON/OFF key and a small keyboard

designed with 11 keys is interfaced with this microcontroller. This keyboard is designed

to generate the data that is stored in RAM and it is delivered through output pin of the

controller (transmitter). The output of the microcontroller is modulated within the ISM

2.4 - 2.4835 GHz frequency band with IEEE 802.15.4 baseband and transmits the binary

data to space. Any digital data generated by the keyboard is transmitted as it is, once the

key is pressed in the transmitter, binary data is transmitted and according to that data, the

receiving controller unit has to be programmed.

The main function of the data transmitting section is to generate 8-bit binary code

that is to be transmitted through Zigbee transmitter. The 8-bit binary code produced by

the keyboard is fed to microcontroller, which functions as encoder; the data obtained

from the keyboard is stored and it is converted into 8-bit information which is transmitted

through amplified modulated input signal. If any key is pressed; that information is

converted into 8-bit data. For example, if No.1 key is pressed, 00000001 code is

generated. Likewise each key function differs from another key to generate a different 8-

bit code. Based on this code, the other micro controller used in the receiving module,

which is designed as 8-bit code decoder, decodes this data and compares with the pre-

defined program prepared in assembly language and operates the vehicle (robot).

The output of the (Encoder) microcontroller is fed to Zigbee

transmitter, for radiating the pulsating energy into air. The function of a

radio frequency (RF) transmitter is to modulate, up convert, and amplify

signals for transmission into free space. An RF transmitter generally

includes a modulator that modulates an input signal and radio frequency

power amplifier that coupled to the modulator to amplify the modulated

input signal. The radio frequency power amplifier is coupled to an antenna

that transmits the amplified modulated input signal.

The Zigbee transmitter used in our project is Tarang – F4. This RF transmitter

transmits data in the frequency range of 2.4 - 2.4835 GHz with a range of approximately

50-feet (open area) outdoors. Indoors, the range is approximately 20 feet, and will go

through most walls. Tarang – F4 has features which includes small in size, low power

consumption and operates at 3.3 volts DC, excellent for applications requiring short-

range RF signal.

Fig 3.1 Zigbee tarang

The data receiving module consist Zigbee receiver, DC motors with their driving

circuits, gun fining sound simulator IC and limit switches that are interfaced with the

89C51 microcontroller as source of information at the receiving side. To control the

moving mechanism based on the input information, H-bridge IC’s are connected at the

output of microcontroller and these are used to control the DC motors ultimately, which

controls the robot as well as the gun firing and its direction. Over all function of the block

diagram is to install an electro-mechanical vehicle operated in all possible directions. The

description is as followed.

The RF signal transmitted by the transmitter is detected and received by this

section of the receiver. This binary encoder data is sent to the decoder for decoding the

original data. The receiver receives an RF signal, converts the RF signal to an IF signal,

and then converts the IF signal to a base band signal, which is then provides to the base

band processor. As is also known, RF transceivers typically include sensitive components

susceptible to noise and interference with one another and with external sources. The

Zigbee (RF) receiver is coupled to the antenna and includes a low noise amplifier, one or

more intermediate frequency stages, a filtering stage, and a data recovery stage. The low

noise amplifier receives an inbound RF signal via the antenna and amplifies it.

The Zigbee receiver receives the RF signal, which is in the frequency

of 2.4 GHz. The receiver operates at 3.3 volts-DC, and has both linear and

digital outputs and its tunable to match the frequency of the transmitter unit.

The program is fixed, it cannot be changed, depending up on the program

prepared for controller, and the information produced by the keyboard at transmitting

end, the received information if it is tallied with the pre-defined program, then the

microcontroller at receiving end energizes the DC motors driving circuit to control or

operate the tanker (robot) automatically.

Depending on the keys pressed from the remote, the data is modulated and

transmitted by the transmitter, which will be demodulated by the receiver present on the

vehicle (ROBOT) and is fed to the 89C51 micro controller. The controller decodes the

data and takes the necessary action depending on the program written in it. The vehicle

(robot) movement can be controlled with the DC motors that will be interfaced to the

controller through the H-bridge IC L293D. By using this IC we will be able to drive two

DC motors. So two H – Bridge IC’s are used to drive the four DC motors. The detailed

explanation of the H-bridge IC operation, and automatic target hit detection system are

explained in the further sections.

3.2 Mechanical actuation section :

The mechanical system is considered as motion converter, this can be created by

implementing electro-mechanical techniques. The concept is to transform the motion

from one form to some other required form by using suitable mechanical and electrical

devices. In this project work the technique of transform the rotational motion into circular

and linear motion is implemented. For this purpose DC motors are used to create the

motion in the gun mechanism of the tanker as well as its movement. These motors are

constructed with reduction gear mechanism which is built in with the motor internally. As

the machine is designed as prototype module, low rating motors are used to drive the

mechanism.

The advantage of selecting reduction gear mechanism motors are that a small

motor can drive heavy loads, as these motors are purchased from local market, ratings

regarding torque is not mentioned. Only speed and operating voltage is specified, as per

this data the motor is designed to operate at 12V DC and the motor speed is 30 RPM.

These motors driving capacity is tested practically, in our test we came to know that each

motor can drive an independent load of maximum 3Kg only. There by according to the

driving capacity of these motors, one small mechanical module is designed for the demo

purpose.

The rotary motion can be transferred from one shaft to another by a pair of rolling

gears. Depending up on the ratio of final shaft speed, number of gears is arranged in

group and is called as gear trains. These gear trains are mechanisms which are widely

used either to increase or to decrease the final shaft speed. When the speed is increased

torque will be reduced, where as if the speed is decreased torque will be increased i.e.,

speed (RPM) and torque are inversely related to each other. In general these teethed gear

wheels are coupled in between two parallel shafts. When two gears are in mesh, the

larger gear wheel is often called as crown wheel and the smaller one is called as pinion.

The movement of the robot will be started by pressing the control buttons in the remote

and the DC motors keep on rotating until the button is released (stop pressing) again.

To control the movement of the gun mechanism and the tanker in various

directions, the DC motors are driven through driver IC’s L293D. The push buttons in the

remote are nothing but the feather touch keys called as push to ON keys. A total of 4 DC

motors are used in this project work, in which 2 DC motors are connected to the right and

left wheels of the robot for the robot movement in forward, backward, right and left

directions. And in the remaining 2 DC motors, one is used to rotate the gun for almost

300 degrees, the other to lift the gun up and down.

A total of 11 push buttons are used to control these DC motors independently.

Each motor is connected with 2 push buttons for operating in clockwise and anti-

clockwise directions. By pressing the push button the H – Bridge IC provides supply to

the DC motor by which the motor rotates in a particular direction. To restrict the

mechanical movement when reached to extreme positions by the gun rotating motor,

limit switches are used to stop the DC motor. As the movement is to be restricted in both

the directions of this motor i.e., clockwise and anti-clockwise 2 limit switches are used.

Out of the 4 DC motors, two are used to control the excavating robot movement

and the rest for controlling the gun of the tanker. The two motors in the gun are used for

rotating and lifting it at desired positions. As mainly load falls on these motors, these are

connected with mechanical gear drive mechanisms. Mechanical drives are used to

provide variable output speed from a constant speed power source. These mechanical

gear drives are extensively used in automobile industry. Mechanical drives provide

simple control and are cheaper as compared to electrical drives.

3.3 Gear Drive :

A gear drive is an assembly of gears turned by the motor to perform the specific

task. The first gear attached to the motor supplies the power and is known as input gear,

while the gear that amplifies the mechanical energy is called the output gear. There are

various types of gear drives such as harmonic drives, bevel gear drives, hypoid gear

drives, combination drives, worm drives, etc and many more. Description about types of

gear drives is provided in the further chapters.

Gears (or cogs) are toothed wheels used for the transmission of power in many

mechanical systems.

When two gears are meshed with each other, a definite velocity ratio is obtained.

Velocity ratio (or gear ratio) is the ratio between the angular velocity of driving gear and

the angular velocity of driven gear.

Gears are typically used for short distance power transmission. They are compact

and have high transmission efficiency when compared to other power transmission

systems. In this project work we use worm gear drive mechanism in the gun lifting and

rotating mechanisms. And the tanker by chain drive mechanism is implemented with

wheels connected to the motors.

Worm gear drives consist of a screw-like worm (comparable to a pinion) that

meshes with a larger gear, usually called a wheel. The worm acts as a screw, several

revolutions of which pull the wheel through a single revolution. In this way, a wide range

of speed ratios up to 60:1 and higher can be obtained from a single reduction. Most

worms are cylindrical in shape with a uniform pitch diameter. However, a double

enveloping worm has a variable pitch diameter that is narrowest in the middle and

greatest at the re ends.

Fig 3.2 Worm gear

This configuration allows the worm to engage more teeth on the wheel, thereby

increasing load capacity. In worm-gear sets, the worm is most often the driving member.

However, a reversible worm-gear has the worm and wheel pitches so proportioned that

movement of the wheel rotates the worm. In most worm gears, the wheel has teeth

similar to those of a helical gear, but the tops of the teeth curve inward to envelop the

worm. As a result, the worm slides rather than rolls as it drives the wheel. Because of this

high level of rubbing between the worm and wheel teeth, the efficiency of worm gearing

is lower than other major gear types.

One major advantage of the worm gear is low wear, due mostly to the full-fluid

lubricant film that tends to be formed between tooth surfaces by the worm sliding action.

A continuous film that separates the tooth surfaces and prevents direct metal-to-

metal contact is typically provided by a relatively heavy oil, which is often

compounded with fatty or fixed oils such as acid less tallow oil. This adds film strength

to the lubricant and further reduces friction by increasing the oiliness of the fluid. The

detailed description about the worm gear drive mechanism is provided in the latter

chapters. As mentioned earlier all these mechanical gear drive mechanisms are driven by

the electric motors.

3.4 DC Motor :

An electric motor is a machine, which converts electrical energy into mechanical

energy. It is based on the principle that when a current-carrying conductor is placed in a

magnetic field, it experiences a mechanical force whose direction is given by Fleming’s

Left-hand rule and whose magnitude is given by

Force, F = B i L Newton

Where ‘B’ is the magnetic field in weber/m2.

‘i’ is the current in amperes and

‘L’ is the length of the coil in meter.

The force, current and the magnetic field are all in different directions.

If an Electric current flows through two copper wires that are between the poles of

a magnet, an upward force will move one wire up and a downward force will move the

other wire down.

A direct current (DC) motor is a fairly simple electric motor that uses electricity

and a magnetic field to produce torque, which turns the motor. At its most simple, a DC

motor requires two magnets of opposite polarity and an electric coil, which acts as an

electromagnet. The repellent and attractive electromagnetic forces of the magnets provide

the torque that causes the DC motor to turn.

Fig 3.3 12V DC motor

In a magnet attraction between opposite poles and the repulsion of similar poles

can easily be felt, even with relatively weak magnets. A DC motor uses these properties

to convert electricity into motion. As the magnets within the DC motor attract and repel

one another, the motor turns.

A DC motor requires at least one electromagnet. This electromagnet switches the

current flow as the motor turns, changing its polarity to keep the motor running. The

other magnet or magnets can either be permanent magnets or other electromagnets.

Often, the electromagnet is located in the center of the motor and turns within the

permanent magnets, but this arrangement is not necessary.

To imagine a simple DC motor, think of a wheel divided into two halves between

two magnets. The wheel of the DC motor in this example is the electromagnet. The two

outer magnets are permanent, one positive and one negative. For this example, let us

assume that the left magnet is negatively charged and the right magnet is positively

charged.

Electrical current is supplied to the coils of wire on the wheel within the DC

motor. This electrical current causes a magnetic force. To make the DC motor turn, the

wheel must have be negatively charged on the side with the negative permanent magnet

and positively charged on the side with the permanent positive magnet. Because like

charges repel and opposite charges attract, the wheel will turn so that its negative side

rolls around to the right, where the positive permanent magnet is, and the wheel's positive

side will roll to the left, where the negative permanent magnet is. The magnetic force

causes the wheel to turn, and this motion can be used to do work.

When the sides of the wheel reach the place of strongest attraction, the electric

current is switched, making the wheel change polarity. The side that was positive

becomes negative, and the side that was negative becomes positive. The magnetic forces

are out of alignment again, and the wheel keeps rotating. As the DC motor spins, it

continually changes the flow of electricity to the inner wheel, so the magnetic forces

continue to cause the wheel to rotate.

DC motors are used for a variety of purposes, including electric razors, electric

car windows, and remote control cars. The simple design and reliability of a DC motor

makes it a good choice for many different uses, as well as a fascinating way to study the

effects of magnetic fields.

DC motors are widely used, inexpensive, small and poweful for their size. They

are most easy to control. One DC motor requires only two singals for its operation. They

are non-polarized, means you can reverse the voltage without any damage to motor. DC

motors have +ve and –ve leads. Connecting them to a DC voltage source moves motor in

one direction (clockwise) and by reversing the polarity, the DC motor will move in

opposite direction (counter clockwise). The maximum speed of DC motor is specified in

rpm (rotation per minute). It has two rpms: no load and loaded. The rpm is reduces when

moving a load or decreases when load increases. Other specifications of DC motors are

voltage and current ratings. Below table shows the specifications of the motor used in the

project.

Speed 30 RPM

Operating Voltage 12V DC

Operating Current 150milliAmps

Table 3.1 DC Motor Specifications

Speed of the motor can be changed by changing the applied voltage across motor.

DC motors don’t have enough torque to drive the mechanism directly by connecting

mechanism with it. The motor driving circuit is designed with L293D chip; this is

popularly known as ‘H’ bridge device generally used to drive the low power DC

motors.To drive these motors independently in both directions, drive sequence is

programmed depending up on the information gathered from the transmitter.

3.5 H-Bridge (General description) :

H-Bridge is an electronic circuit which enables a voltage to be applied on either

side of the load and the H-bridge DC motors allow the car to run backwards or forwards.

H-Bridge is a configuration of 4 switches, which switch in a specific manner to control

the direction of the current through the motor. Below figure shows simplified H-bridge as

switches. The states of these four switches can be changed in order to change the voltage

across the motor, of the current flow and the rotation of motor.

Fig 3.4 Basic Structure of an H-Bridg

In above figure, all switches are open and the motor terminals are disconnected

from the circuit. This state allows the motor to spin freely. If we open switches S1 & S4

and close S2 & S3 as in first part of below figure there will be current flow across the

circuit and motor will run. But if S1, S4 are close and S2, S3 are open, the voltage across

the motor will switch around and that will cause the motor to rotate in the opposite

direction. Below table summarizes the basic operation of the H-bridge depending upon

the voltage applied across the switches.

S1 S2 S3 S4 Result

1 0 0 1 Motor moves right

0 1 1 0 Motor moves left

0 0 0 0 Motor free runs

0 1 0 1 Motor brakes

1 0 1 0 Motor brakes

Table 3.2 H-Bridge Operation Summary

Fig 3.5 Two basic states of an H-Bridge

To control the speed and direction of the DC motor from the microcontroller, this

simple H-bridge will be of no use. H-bridge which makes use of transistors works best

for robotics projects. These transistors work as switch and they can control the current

flow in the motor easily. Below figure shows transistor as a switch.

Fig 3.6 Transistors as a Switch

The difference between the mechanical switch and the transistor switch is that

mechanical switch can be turned on or off mechanically but a transistors switch can be

turned on or off by applying small current at the base. For an NPN transistor, when a

small current of 20mA is applied to the base of the transistor, current will flow from

collector to emitter. In case of, for PNP transistor, the current will flow from emitter to

collector. For transistor to work as switch, the applied voltage at base needs to be higher

than collector voltage for NPN transistor and lower than collector voltage for PNP

transistor.

In this project, the dual H-bridge motor driver IC used is L293D. “The L293D is a

monolithic integrated, high voltage, high current, 4-channel driver”. The L293D supports

two DC motors. Pin 8 is voltage for the motors and pin 16 is the +5 voltage for the chip.

So with one IC we can interface two DC motors which can be controlled in both

clockwise and counter clockwise direction and if you have motor with fix direction of

motion then we can make use of all the four I/Os to connect up to four DC motors. First

motor is connected between pin 3 and 6. The motor is turned on by sending a high signal

to both the enable (pin 1) pin and one of the two direction pins, i.e. pin 2 or pin 7. To stop

motor, the enable pin is high and both pin 2 and pin 7 are low. L293D has output current

of 600mA and peak output current of 1.2A per channel. Moreover for protection of

circuit from back EMF output diodes are included within the IC. The output supply

(VCC2) has a wide range from 4.5V to 36V, which had made L293D a best choice for

DC motor driver.

Fig 3.7 DC Motor Control with H-Bridge

The same goes for the other side of the chip. When using two motors, the best

practice is to connect pins 2 and 15 togather and pin 7 and 10. above figure shows the

control of the DC motors with L293D and microcontroller signal.

Fig 3.8 L293D H Bridge (Motor Driver)

Motor drivers are the simplest modules that provide power amplification for low-

level control singals like PWM and direction supplied by the user.

Depending on the command signals given from the remote, the controller decodes

the information and takes decisions appropriately. The vehicle (robot) movement is

performed using two DC motors driven by a single H - Bridge IC. So four keys in the

remote control the tanker directions i.e., forward, backward, right and left. One more H –

Bridge IC is used to drive the two DC motors for controlling the gun direction in

rotational mechanism and lifting up and down present on the vehicle itself. Out of the two

DC motors, one motor is used to to lift the gun to certain height and the second DC motor

is used to rotate the gun to desired position. The DC motor is also to be rotated in the

reverse direction and by reversing the polarities, the motor rotates in the reverse direction

that is done by the controller through the H - Bridge IC’s. The mechanical movements of

the above mentioned mechanism using two DC motors is designed using gear drive

mechanisms for the required mechanical motions.

3.6 LIMIT SWITCHES :

In engineering a limit switch is a switch operated by the motion of a machine part

or presence of an object. They are used for control of a machine, as safety interlocks, or

to count objects passing a point. A limit switch is an electromechanical device that

consists of an actuator mechanically linked to a set of contacts. When an object comes

into contact with the actuator, the device operates the contacts to make or break an

electrical connection. Limit switches are used in a variety of applications and

environments because of their ruggedness, ease of installation, and reliability of

operation. They can determine the presence or absence, passing, positioning, and end of

travel of an object. They were first used to define the limit of travel of an object; hence

the name “Limit Switch.”

Standardized limit switches are industrial control components manufactured with

a variety of operator types, including lever, roller plunger, and whisker type. Limit

switches may be directly mechanically operated by the motion of the operating lever. A

reed switch may be used to indicate proximity of a magnet mounted on some moving

part. Proximity switches operate by the disturbance of an electromagnetic field, by

capacitance, or by sensing a magnetic field.

Rarely, a final operating device such as a lamp or solenoid valve will be directly

controlled by the contacts of an industrial limit switch, but more typically the limit switch

will be wired through a control relay, a motor contactor control circuit, or as an input to a

programmable logic controller.

Miniature snap-action switch may be used for example as components of such

devices as photocopiers or computer printers, to ensure internal components are in the

correct position for operation and to prevent operation when access doors are opened. A

set of adjustable limit switches are installed on a garage door opener to shut off the motor

when the door has reached the fully raised or fully lowered position. A numerical control

machine such as a lathe will have limit switches to identify maximum limits for machine

parts or to provide a known reference point for incremental motions.

In this project work also the mechanical movements are restricted through limit

switches and these entire limit switches are interfaced with the H – bridge IC’s as input

signals. As mentioned earlier, 2 limit switches are used to restrict the mechanical motion

by stopping the DC motors when reached to maximum extent. This limit switch is having

long lever and when little pressure is applied to the lever, switch will be activated

automatically. The mechanical transmission section that moves the excavating robot arm

in three degrees of freedom activates these switches at various levels. The following is

the diagram of limit switch.

Fig 3.9 Limit Switch

The limit switch shown above is having long lever, like this ten limit switches are

used, and they are arranged at different positions of the mechanical structure to control

the movement of mechanical transmission section. The motion of the motor in the form

mechanical movement, if it touches to the lever, than the switch is activated and

generates a logic signal to the DC motor. Based on this signals produced by these limit

switches, the mechanical movements of entire machine are restricted by the DC motors.

3.7 UM 3562 (GUN SOUNDS GENERATOR) :

General Description:

The IC UM 3562 used in this project is a low cost, low power CMOS LSI

designed for use in toy application. Since the IC includes oscillating and selector circuits,

a compact sound module can be constructed with only a few additional components. The

UM 3562 contains circuit to produce three gun sounds. The circuit constructed here has a

facility to adjust machine gun shooting rate. For this resistor R1 and R2 are given as

optional with dotted marking on PCB. If shooting rate is not to be adjusted then resistor

R1 and R2 may be omitted.

Fig 3.10 UM 3562

FEATURES:

Three sounds can be selected

1) Rifle Gun

2) Machine Gun

3) Laser Gun

Typical 3V operating voltage

RC Oscillator built-in

A magnetic speaker can be driven by connecting NPN transistor

Power ON reset

PIN DESCRIPTION

Pin No. Destination Description

1 OSC

This pin is used for testing in normal operation

the pin is open.

2 SEL Sound effect select pin.

3 VSS Negative Power Supply

4 TRI Trigger pin

5 OUTPUT Monotone Output

6 ADJ Normally open, may connect a resistor to ground

to adjust machine gun shoots rates.

7 NC No connection

8 VDD Positive power supply

Table 3.3 Pin description table

A relay is used to activate this chip when gun firing is to be done. The controller

control the operation of the relay depending on the key pressed in the remote in manual

operation. Else in the automatic mode of operation also, depending on the direction of the

hit target, the controller automatically rotates the gun to that particular direction and

activates this chip through the relay to fire.

3.8 Relay :

A relay is an electromagnetic switch, which can be used to make or break the

circuit. Here a relay is connected at the output of the microcontroller to control the gun

firing sound generator IC. The relay used here is having only one set of changing over

contact, when this relay is energized normally open contact gets closed and supply is

provided to the sound generator IC. When the same relay is de-energized, normally open

contact remains in open condition and supply is disconnected to the device. The contact

rating of the relay is 1.5 amps; less than 1.5 amps restrict so current flowing through the

contact. If any heavy load device is used, higher rating relay must be selected

accordingly.

A relay is an electrical switch that opens and closes under the control of another

electrical circuit. In the original form, the switch is operated by an electromagnet to open

or close one or many sets of contacts. These contacts can be either Normally Open (NO),

Normally Closed (NC), or change-over contacts. A relay is able to control an output

circuit of higher power than the input circuit, it can be considered to be, in a broad sense,

a form of an electrical amplifier. So a relay can be defined as an automatic

electromagnetic/electronic switch, which can be used to make or break the circuit.

The relay used in this project work is electro-magnetic/mechanical relay. The

electromagnetic relay is basically a switch (or a combination of switches) operated by the

magnetic force generated by a current flowing through a coil. Essentially, it consists of

four parts an electromagnet comprising a coil and a magnetic circuit, a movable armature,

a set of contacts, and a frame to mount all these components. However, very wide ranges

of relays have been developed to meet the requirements of the industry. This relay is

nothing but a switch, which operates electromagnetically. It opens or closes a circuit

when current through the coil is started or stopped. When the coil is energized armature

is attracted by the electromagnet and the contacts are closed. That is how the power is

applied to the signals (indicators). The construction of the typical relay contains a code

surrounded by a coil of copper wire. The core is mounted on a metal frame. The movable

part of the relay is called armature. When a voltage is applied to the coil terminals, the

current flowing through the coil produces a magnetic field in the core. In other words, the

core acts as an electromagnet and attracts the metal armature. When the armature is

attracted to the core, the magnetic path is from the core through armature, through the

frame, and back to the core. On removing the voltage the spring attached to the armature

returns the armature to its original position. In this position, there is a small air-gap in the

magnetic path. Hence, more power is needed to pull in the armature than that needed to

keep it held in the attracted position.

The electromagnetic relay, one of mankind’s first electrical device, was used

practically in telegraphy as early as 1850. The modern relay, properly applied, is one of

the most simple, effective and dependable component available. In the majority of

instances, it can achieve better reliability at lesser cost than an equivalent solid-state

complex type of relay. The term ‘relay’ was used for the first time to describe an

invention made by Samuel Morse in 1836. The device invented by Morse was a

“Telegraph Amplifying Electromagnetic Device” which enabled a small current flowing

in a coil to switch on a large current in another circuit and thus helped in “relay” of

signals.

A relay is a device that opens or closes an auxiliary circuit under some

predetermined condition in the main circuit. The object of a relay is generally to act as a

sort of electric magnifier, that is to say, it enables a comparatively weak current to bring

into operation a much stronger current. It also provides complete electrical isolation

between the controlling circuit and the controlled circuit. The relay is operated like a

switch to control the gun firing sound generator IC. The controller controls the operation

of the relay i.e., ON and OFF by which the device is also controlled.

The relay contacts and the terminals are mounted on an insulated board. When no

current flows through the relay coil, the contact arm, or pole as it is called, mounted on

the armature, touches the “top” (N/C) contact. When the coil is energized by flow of

current, the armature along with the contact arm assembly moves downwards; so that the

contact arm touches the “bottom” (N/O) contact. When an electric current is flowing

through a relay coil, it is said to be energized, and when the current flow stops, the relay

is said to be de-energized. They have a set of parallel contacts, which are all pulled in

when the electromagnet pulls in the armature. On being energized, whether a relay makes

contact(s) or breaks them depends on the design of contact arrangements. Though the

contacts are open or close simultaneously, the sequence of operation cannot be

guaranteed in this of construction. To have a definite switching sequence, stacked

contacts are used.

Fig 3.11 Schematic of relay with contact

3.9 Automatic mode :

The mechanical construction of the war tanker is constructed with metal plates in

a hexagon shape. So the gun detects the hit target from all these six directions. Each

metal plate is also bent around 45 degrees to identify the hit targets from the air. So this

way six metal plates detects 12 directions i.e., six for the horizontal sideways and six

more for the aired targets hitting purpose. These metal plates are connected with positive

power supply of 5 volts and a thin metal mesh is placed individually over the metal plates

with some gap using spacers for all the 12 sides of the tanker. And these metal meshes

are connected to the controller like inputs to detect the target hit direction. If any target

hits, the mesh gets into contact with the metal plate by which the controller gets a logic

high signal to identify the direction of the hit target. So the controller automatically

controls the gun direction to the target hit direction and starts firing.

3.10 Power source :

The required power supply to drive the excavating robot is derived by 12V, 7.5

Ah (Ampere hour), rechargeable, lead acid heavy duty battery. Here we require three

different DC levels of +5V, +9V and +12V. The battery as it is delivering 12V is used to

drive the DC motors through the H Bridge IC’s, where as for the remaining electronic

circuitry consists of microcontroller, ADC, 555 timer chip, LCD and RF receiver requires

+5V constant source. The wireless video camera requires a constant regulated supply of

+9V DC. To generate a stable supply of +5V, 7805 three terminal voltage regulator chip

is used which provides constant supply, though the battery terminal voltage falls down to

8V. In the same way for deriving +9V, 7809 voltage regulator is used. The DC motors

are designed to operate at 12V DC and each motor consumes a maximum current of 150

milli-amps, there by four motors for the robot movement together consumes 600 milli-

amps. Likewise by calculating the current drawn by the entire circuit, the backup time of

the battery can be calculated. The relation for calculating the backup time is given as:

The battery backup time = battery rating in Ah/ consumed energy (current drawn by the

entire circuit in Amps).

CHAPTER – 4

MICRO CONTROLLERS

4.1 INTRODUCTION :

A Micro controller consists of a powerful CPU tightly coupled with memory,

various I/O interfaces such as serial port, parallel port timer or counter, interrupt

controller, data acquisition interfaces-Analog to Digital converter, Digital to Analog

converter, integrated on to a single silicon chip. If a system is developed with a

microprocessor, the designer has to go for external memory such as RAM, ROM,

EPROM and peripherals.

But controller is provided all these facilities on a single chip. Development of a

Micro controller reduces PCB size and cost of design. One of the major differences

between a Microprocessor and a Micro controller is that a controller often deals with bits

not bytes as in the real world application.

Intel has introduced a family of Micro controllers called the MCS-51.The

microcontroller plays the major role in any embedded project. In this my project we use

three microcontrollers they are made by the ATMEL Company. In which two are

AT89C51/52 and the other is AT 89C2051.

4.2 Necessity of microcontrollers :

Microprocessors brought the concept of programmable devices and made many

applications of intelligent equipment. Most applications, which do not need large amount

of data and program memory, tended to be costly.

The microprocessor system had to satisfy the data and program requirements so;

sufficient RAM and ROM are used to satisfy most applications .The peripheral control

equipment also had to be satisfied. Therefore, almost all-peripheral chips were used in the

design. Because of these additional peripherals cost will be comparatively high.

An example:

8085 chip needs an Address latch for separating address from multiplex address

and data.32-KB RAM and 32-KB ROM to be able to satisfy most applications. As also

Timer / Counter, Parallel programmable port, Serial port, and Interrupt controller are

needed for its efficient applications.

In comparison a typical Micro controller 8051 chip has all that the 8051

board has except a reduced memory i.e; 4K bytes of ROM as compared to

32-KB, 128 Bytes of RAM as compared to 32-KB.

Typical Micro controller has all the following features

8/16/32 CPU

Instruction set rich in I/O & bit operations.

One or more I/O ports.

One or more timer/counters.

One or more interrupt inputs and an interrupt controller

One or more serial communication ports.

Analog to Digital /Digital to Analog converter

One or more PWM output

Network controlled interface

4.3 ADVANTAGES OF MICROCONTROLLER :

1. If system is developed with a microprocessor, the designer has to go for external

memory such as RAM, ROM or EPROM and peripherals and hence the size of PCB will

be large enough to hold all the required peripherals. But, the micro controller has got all

this peripheral facility on a single chip o development of a similar system with a micro

controller reduces PCB size and cost of the design.

2. One of the major differences between a micro controller and a microprocessor is that a

controller often deals with bits, not bytes as in the real world application, for example

switch contacts can only be open or close, indicators should be lit or dark and motors can

be either turned on or off and so forth.

3. On comparing a board full of chips (Microprocessors) which is bulky with one chip

with all components in it (Micro controller) which is very simple.

4. Lots of Microprocessor circuitry and program to debug. In Micro controller there is no

Microprocessor circuitry to debug.

5. As we have observed Microprocessors need a lot of debugging at board level and at

program level, whereas, Micro controller do not have the excessive circuitry and the

built-in peripheral chips are easier to program for operation. So peripheral devices like

Timer/Counter, Parallel programmable port, Serial Communication Port, Interrupt

controller and so on, which were most often used were integrated with the

Microprocessor to present the Micro controller .RAM and ROM also were integrated in

the same chip. The ROM size was anything from 256 bytes to 32Kb or more. RAM was

optimized to minimum of 64 bytes to 256 bytes or more.

4.4 AT89C51 TYPE MICRO CONTROLLER :

The system requirements and control specifications clearly rule out the use of 16,

32 or 64 bit micro controllers or microprocessors. Systems using these may be earlier to

implement due to large number of internal features. They are also faster and more reliable

but, the above application is satisfactorily served by 8-bit micro controller. Using an

inexpensive 8-bit Microcontroller will doom the 32-bit product failure in any competitive

market place.

Coming to the question of why to use P89V51RD2 of all the 8-bit Microcontroller

available in the market the main answer would be because it has 64 kB Flash and 1024

bytes of data RAM. . The Flash program memory supports both parallel programming

and in serial In-System Programming (ISP). The P89V51RD2 is also In-Application

Programmable (IAP), allowing the Flash program memory to be reconfigured even while

the application is running.

The generic 8051 architecture supports a Harvard architecture, which contains two

separate buses for both program and data. So, it has two distinctive memory spaces of

64K X 8 size for both programmed and data.

It is based on an 8 bit central processing unit with an 8 bit Accumulator and

another 8 bit B register as main processing blocks. Other portions of the architecture

include few 8 bit and 16 bit registers and 8 bit memory locations.

4.5 FEATURES OF 8051 ARCHITECTURE :

1) Optimized 8 bit CPU for control applications and extensive Boolean

processing capabilities.

2) 64K Program Memory address space.

3) 64K Data Memory address space.

4) 128 bytes of on chip data memory out of which 4 register banks, each

containing 8 registers, 16 bytes, which are addressed at the bit level and 80 bytes

of general- purpose data memory.

5) 32 Bi-directional and individually addressable I/O lines.

6) Two 16 bit timer/counters.

7) Full Duplex UART.

8) 6-source / 5-vector interrupt structure with priority levels.

9) On chip clock oscillator.

Now we may be wondering about the non-mentioning of memory space

meant for the program storage, the most important part of any embedded

controller. Originally this 8051 architecture was introduced with on-chip, ‘one

time programmable’ version of Program Memory of size 4K X 8.

Intel delivered all these microcontrollers (8051) with user’s program fused

inside the device. The memory portion was mapped at the lower end of the

Program Memory area. But, after getting devices, customers couldn’t change

anything in their program code, which was already made available inside during

device fabrication.

The 8051 architecture consists of these specific features:

Eight –bit CPU with registers A (the accumulator) and B

Sixteen-bit program counter (PC) and data pointer (DPTR)

Eight- bit stack pointer (PSW)

Eight-bit stack pointer (Sp)

Internal ROM or EPROM (8751) of 0(8031) to 4K (8051)

Internal RAM of 128 bytes:

Thirty –two input/output pins arranged as four 8-bit ports:p0-p3

Two 16-bit timer/counters: T0 and T1

Full duplex serial data receiver/transmitter: SBUF

Control registers: TCON, TMOD, SCON, PCON, IP, and IE

Two external and three internal interrupts sources.

Oscillator and clock circuits.

4.6 PIN DIAGRAM :

Fig 4.1 Pin diagram of 89C51 IC

Fig 4.2 Functional block diagram of micro controller

4.7 PORT 3 PINS ALTERNATIVE FUNCTIONS :

All four ports in the 89C51 are bidirectional. Each consists of a latch (Special

Function Registers P0 through P3), an output driver, and an input buffer. The output

drivers of Ports 0 and 2, and the input buffers of Port 0, are used in accesses to external

memory. In this application, Port 0 outputs the low byte of the external memory address,

time-multiplexed with the byte being written or read. Port 2 outputs the high byte of the

external memory address when the address is 16 bits wide. Otherwise, the Port 2 pins

continue to emit the P2 SFR content.

All the Port 3 pins are multifunctional. They are not only port pins, but also serve

the functions of various special features as listed below:

Port Pin Alternate Function

P3.0 RxD (serial input port)

P3.1 TxD (serial output port)

P3.2 INT0 (external interrupt)

P3.3 INT1 (external interrupt)

P3.4 T0 (Timer/Counter 0 external input)

P3.5 T1 (Timer/Counter 1 external input)

P3.6 WR (external Data Memory write strobe)

P3.7 RD (external Data Memory read strobe)

VCC Supply voltage

VSS Circuit ground potential

4.7.1 The 8051 Oscillator and Clock :

The heart of the 8051 circuitry that generates the clock pulses by which all the

internal all internal operations are synchronized. Pins XTAL1 And XTAL2 is provided

for connecting a resonant network to form an oscillator. Typically a quartz crystal and

capacitors are employed. The crystal frequency is the basic internal clock frequency of

the microcontroller. The manufacturers make 8051 designs that run at specific minimum

and maximum frequencies typically 1 to 16 MHz.

Fig 4.3 Oscillator and timing circuit

4.8 TYPES OF MEMORY :

The 8051 have three general types of memory. They are on-chip memory,

external Code memory and external Ram. On-Chip memory refers to physically existing

memory on the micro controller itself. External code memory is the code memory that

resides off chip. This is often in the form of an external EPROM. External RAM is the

Ram that resides off chip. This often is in the form of standard static RAM or flash

RAM.

4.8.1 Code memory :

Code memory is the memory that holds the actual 8051 programs that is to be run.

This memory is limited to 64K. Code memory may be found on-chip or off-chip. It is

possible to have 4K of code memory on-chip and 60K off chip memory simultaneously.

If only off-chip memory is available then there can be 64K of off chip ROM. This is

controlled by pin provided as EA.

4.8.2 Internal RAM

The 8051 have a bank of 128 bytes of internal RAM. The internal RAM is found

on-chip. So it is the fastest Ram available. And also it is most flexible in terms of reading

and writing. Internal Ram is volatile, so when 8051 is reset, this memory is cleared. 128

bytes of internal memory are subdivided. The first 32 bytes are divided into 4 register

banks. Each bank contains 8 registers. Internal RAM also contains 128 bits, which are

addressed from 20h to 2Fh. These bits are bit addressed i.e. each individual bit of a byte

can be addressed by the user. They are numbered 00h to 7Fh. The user may make use of

these variables with commands such as SETB and CLR.

4.9 SPECIAL FUNCTION REGISTERED MEMORY

Special function registers are the areas of memory that control specific

functionality of the 8051 micro controller.

1.Accumulator (0E0h) :

As its name suggests, it is used to accumulate the results of large no of

instructions. It can hold 8 bit values.

2.B register (0F0h) :

The B register is very similar to accumulator. It may hold 8-bit value. The b

register is only used by MUL AB and DIV AB instructions. In MUL AB the higher byte

of the product gets stored in B register. In div AB the quotient gets stored in B with the

remainder in A.

3.Stack pointer (81h) :

The stack pointer holds 8-bit value. This is used to indicate where the next value

to be removed from the stack should be taken from. When a value is to be pushed onto

the stack, the 8051 first stores the value of SP and then store the value at the resulting

memory location. When a value is to be popped from the stack, the 8051 returns the

value from the memory location indicated by SP and then decrements the value of SP.

4.Data pointer :

The SFRs DPL and DPH work together work together to represent a 16-bit value

called the data pointer. The data pointer is used in operations regarding external RAM

and some instructions code memory. It is a 16-bit SFR and also an addressable SFR.

5.Program counter :

The program counter is a 16 bit register, which contains the 2 byte address, which

tells the 8051 where the next instruction to execute to be found in memory. When the

8051 is initialized PC starts at 0000h. And is incremented each time an instruction is

executes. It is not addressable SFR.

6.PCON (power control, 87h) :

The power control SFR is used to control the 8051’s power control modes.

Certain operation modes of the 8051 allow the 8051 to go into a type of “sleep mode”

which consumes much less power.

Fig 4.4 PCON register.

7.TCON (timer control, 88h) :

The timer control SFR is used to configure and modify the way in which the

8051’s two timers operate. This SFR controls whether each of the two timers is running

or stopped and contains a flag to indicate that each timer has overflowed. Additionally,

some non-timer related bits are located in TCON SFR. These bits are used to configure

the way in which the external interrupt flags are activated, which are set when an

external interrupt occurs.

Fig 4.5 TCON registers

8.TMOD (Timer Mode, 89h) :

The timer mode SFR is used to configure the mode of operation of each of the

two timers. Using this SFR your program may configure each timer to be a 16-bit timer,

or 13 bit timer, 8-bit auto reload timer, or two separate timers. Additionally you may

configure the timers to only count when an external pin is activated or to count “events”

that are indicated on an external pin.

Fig 4.6 TMOD

9.TO (Timer 0 low/high, address 8A/8C h) :

These two SFR’s taken together represent timer 0. Their exact behavior depends

on how the timer is configured in the TMOD SFR; however, these timers always count

up. What is configurable is how and when they increment in value.

10.T1 (Timer 1 Low/High, address 8B/ 8D h) :

These two SFRs, taken together, represent timer 1. Their exact behavior depends

on how the timer is configured in the TMOD SFR; however, these timers always count

up.

11.P0 (Port 0, address 90h, bit addressable) :

This is port 0 latch. Each bit of this SFR corresponds to one of the pins on a micro

controller. Any data to be outputted to port 0 is first written on P0 register. For e.g., bit 0

of port 0 is pin P0.0, bit 7 is pin p0.7. Writing a value of 1 to a bit of this SFR will send a

high level on the corresponding I/O pin whereas a value of 0 will bring it to low level.

12.P1 (port 1, address 90h, bit addressable) :

This is port latch1. Each bit of this SFR corresponds to one of the pins on a micro

controller. Any data to be outputted to port 0 is first written on P0 register. For e.g., bit 0

of port 0 is pin P1.0, bit 7 is pin P1.7. Writing a value of 1 to a bit of this SFR will send

a high level on the corresponding I/O pin whereas a value of 0 will bring it to low level.

13.P2 (port 2, address 0A0h, bit addressable) :

This is a port latch2. Each bit of this SFR corresponds to one of the pins on a

micro controller. Any data to be outputted to port 0 is first written on P0 register. For e.g.,

bit 0 of port 0 is pin P2.0, bit 7 is pin P2.7. Writing a value of 1 to a bit of this SFR will

send a high level on the corresponding I/O pin whereas a value of 0 will bring it to low

level.

14.P3 (port 3, address B0h, bit addressable) :

This is a port latch3. Each bit of this SFR corresponds to one of the pins on a

micro controller. Any data to be outputted to port 0 is first written on P0 register. For e.g.,

bit 0 of port 0 is pin P3.0, bit 7 is pin P3.7. Writing a value of 1 to a bit of this SFR will

send a high level on the corresponding I/O pin whereas a value of 0 will bring it to low

level.

15.IE (interrupt enable, 0A8h) :

The Interrupt Enable SFR is used to enable and disable specific interrupts. The

low 7 bits of the SFR are used to enable/disable the specific interrupts, where the MSB

bit is used to enable or disable all the interrupts. Thus, if the high bit of IE is 0 all

interrupts are disabled regardless of whether an individual interrupt is enabled by setting

a lower bit.

Fig 4.7 IE Registers

16.IP (Interrupt Priority, 0B8h) :

The interrupt priority SFR is used to specify the relative priority of each interrupt.

On 8051 an interrupt may be either low or high priority. An interrupt may interrupt

interrupts. For e.g., if we configure all interrupts as low priority other than serial

interrupt. The serial interrupt always interrupts the system, even if another interrupt is

currently executing. However, if a serial interrupt is executing no other interrupt will be

able to interrupt the serial interrupt routine since the serial interrupt routine has the

highest priority.

Fig 4.8 IP registers

17.PSW (Program Status Word, 0D0h) :

The program Status Word is used to store a number of important bits that are set

and cleared by 8051 instructions. The PSW SFR contains the carry flag, the auxiliary

carry flag, the parity flag and the overflow flag. Additionally, it also contains the register

bank select flags, which are used to select, which of the “R” register banks currently in

use.

Fig 4.9 PSW registers

18.SBUF (Serial Buffer, 99h) :

SBUF is used to hold data in serial communication. It is physically two registers.

One is writing only and is used to hold data to be transmitted out of 8051 via TXD. The

other is read only and holds received data from external sources via RXD. Both mutually

exclusive registers use address 99h.

19.I/O Ports :

One major feature of a microcontroller is the versatility built into the input/output

(I/O) circuits that connect the 8051 to the outside world. The main constraint that limits

numerous functions is the number of pins available in the 8051 circuit. The DIP had 40

pins and the success of the design depends on the flexibility incorporated into use of

these pins. For this reason, 24 of the pins may each used for one of the two entirely

different functions which depend, first, on what is physically connected to it and, then, on

what software programs are used to “program” the pins.

20.PORT 0 :

Port 0 pins may serve as inputs, outputs, or, when used together, as a bi

directional low-order address and data bus for external memory. To configure a pin as

input, 1 must be written into the corresponding port 0 latch by the program. When used

for interfacing with the external memory, the lower byte of address is first sent via

PORT0, latched using Address latch enable (ALE) pulse and then the bus is turned

around to become the data bus for external memory.

21.PORT 1 :

Port 1 is exclusively used for input/output operations. PORT 1 pins have no dual

function. When a pin is to be configured as input, 1 is to be written into the

corresponding Port 1 latch.

22.PORT 2 :

Port 2 may be used as an input/output port. It may also be used to supply a high –

order address byte in conjunction with Port 0 low-order byte to address external memory.

Port 2 pins are momentarily changed by the address control signals when supplying the

high byte a 16-bit address. Port 2 latches remain stable when external memory is

addressed, as they do not have to be turned around (set to 1) for data input as in the case

for Port 0.

23.PORT 3 :

Port 3 may be used to input /output port. The input and output functions can be

programmed under the control of the P3 latches or under the control of various special

function registers. Unlike Port 0 and Port 2, which can have external addressing functions

and change all eight-port b se, each pin of port 3 maybe individually programmed to be

used as I/O or as one of the alternate functions. The Port 3 alternate uses are:

Pin (SFR) Alternate Use

P3.0-RXD (SBUF) Serial data input

P3.1-TXD (SBUF) Serial data output

P3.2-INTO 0 (TCON.1) External interrupt 0

P3.3 - INTO 1 (TCON.3) External interrupt 1

P3.4 - T0 (TMOD) External Timer 0 input

P3.5 – T1 (TMOD) External timer 1 input

P3.6 - WR External memory write pulse

P3.7 - RD External memory read pulse

Table 4.1 Port 3 Alternate Uses

4.10 INTERRUPTS :

Interrupts are hardware signals that are used to determine conditions that exist in

external and internal circuits. Any interrupt can cause the 8051 to perform a hardware

call to an interrupt –handling subroutine that is located at a predetermined absolute

address in the program memory.

Five interrupts are provided in the 8051. Three of these are generated

automatically by the internal operations: Timer flag 0, Timer Flag 1, and the serial port

interrupt (RI or TI) Two interrupts are triggered by external signals provided by the

circuitry that is connected to the pins INTO 0 and INTO1. The interrupts maybe enable or

disabled, given priority or otherwise controlled by altering the bits in the Interrupt

Enabled (IE) register, Interrupt Priority (IP) register, and the Timer Control (TCON)

register. . These interrupts are mask able i.e. they can be disabled. Reset is a non

maskable interrupt which has the highest priority. It is generated when a high is applied

to the reset pin. Upon reset, the registers are loaded with the default values.

Each interrupt source causes the program to do store the address in PC onto the

stack and causes a hardware call to one of the dedicated addresses in the program

memory. The appropriate memory locations for each for each interrupt are as follows:

Interrupt Address

RESET 0000

IE0 (External interrupt 0) 0003

TF0 (Timer 0 interrupt) 000B

IE1 (External interrupt 1) 0013

TF1 (Timer 1 interrupt) 001B

SERIAL 0023

Table 4.2 Interrupts

CHAPTER – 5

SOFTWARE DESCRIPTION

In our project we used software that is Keil micro vision for the simulation of the

program.

5.1 KEIL SOFTWARE :

Keil development tools for the 8051 Microcontroller Architecture support every

level of software developer from the professional applications engineer to the student just

learning about embedded software.

The industry-standard Keil C Compilers, Macro Assemblers, Debuggers, Real-

time Kernels, Single-board Computers, and Emulators support all 8051 derivatives and

help you get your projects completed on schedule.

5.2 SIMULATION :

The µVision Simulator allows you to debug programs using only your PC using

simulation drivers provided by Keil and various third-party developers. A good

simulation environment, like µVision, does much more than simply simulate the

instruction set of a microcontroller — it simulates your entire target system including

interrupts, startup code, on-chip peripherals, external signals, and I/O.

5.3 SOFTWARE FOR EXECUTION OF MICROCONTROLLER

PROGRAMS :

Keil development tools for the MC architecture support every level of software

developer from the professional applications engineer to the student just learning about

embedded software development.

The industry-standard Keil-C compilers, macro assemblers, debuggers, real, time

Kernels, Single-board computers and emulators support all microcontroller derivatives

and help you to get more projects completed on schedule. The Keil software development

tools are designed to solve the complex Problems facing embedded software developers.

Those are listed below.

5.4 PROBLEMS FACED BY EMBEDDED SOFTWARE

DEVELOPERS :

1. When starting a new project, simply select the microcontroller you the device

database and the µvision IDE sets all compiler, assembler, linker, and memory

options for you.

2. The Keil µ Vision debugger accurately simulates on-chip peripherals (PC, CAN,

UART, SPI, Interrupts, I/O ports, A/D converter, D/A converter and PWM

modules)of your aver device.

3. Simulation helps you understand h/w configurations and avoids time wasted on

setup problems. Additionally, with simulation, you can write and test applications

before target h/w is available.

4. When you are ready to begin testing your s/w application with target h/w, use the

MON51, MON390, MONADI, or flash MON51 target monitors, the ISD51 In-

System Debugger, or the ULINK USB-JTAG adapter to download and test

program code on your target system.

CHAPTER-6

SCOPE OF DEVELOPMENT

For the human operator to command the unmanned systems, technologies that

need to be mastered include artificial intelligence, radio-frequency technology and micro-

controllers. This prototype model resembles the actual idea of our project. The main aim

behind this project are mentioned below:

1. An army tanker which is controlled by remote.

2. It’s an un-manned war tanker.

3. Manually and Automatic controlled.

4. Self defending.

5. Self attacking.

6. Live visual coverage of war.

7. 360 degrees rotation of main gun.

8. Min.. speed 35mph.

9. 3 secondary machine guns.

10. Auto angle adjustment of main gun.

11. 5Ghz transmitter and receiver.

12. 6 DOF.

13. Highly Withstood.

14. Long distance working.

15. Sustainable in all weather conditions.

The need of this UGV (Un-manned Ground Vehicles) was primarily the

protection of the soldiers. The life of a human is more precious than a war tanker. Since

this systems are highly accurate in attacking the targets the surroundings are left

undamaged. Apart from main gun this tanker will be equipped with 3 machine guns to

destroy the multiple targets in its range.

6.1 LIMITATIONS :

Despite these advantages, there are several limitations which must be

recognized and reconciled. Few of the facts even effected our prototype modal.

Some of the limitations include:

1. High initial cost : Since the equipments and the materials required to build such

type of army tankers are very costly, the investment to make a prototype can be

very high though the government claims the subsidies.

2. High performance engine : The load of ammos and the electrical system carried

by the tanker is very heavy in weight. Thus the additions to the tanker may cause

very slow speed and more power consumption is needed to run the electrical

parts. So, installing a very high performance diesel engine is recommended which

can not only provide power to the system but also have good speed.

Example : A multi-fuel turbine diesel engine with 2500 BHp to power up the

entire system and can provide the speed of 35Mph for a tanker of weight 80-85

tones

3. Non-movable : When the tanker in a war is attacking it remains stationary at one

place. The vehicle cannot move and attack simultaneously.

4. Maintenance : The cost of maintaining this UGV is very high and even it

requires highly skilled technician to repair and maintain the parts.

6.2 FUTURE SCOPE :

1. RADAR : In future the prototype may be equipped with RADAR to detect

the targets and destroy them. The range can be set to 10-15 miles in radius to detect and

5-8 miles radius to destroy the target.

2. Artificial intelligence : Though its automatic, it needs a operator to move

the vehicle in different directions. These defect can be solved in future by implanting the

artificial intelligence.

3. Cameras : By installing cameras (Normal and night vision), the army can

get the live visuals of the war in day and in the night. Which can even helpful to detect

the enemy locations from a long range.

4. Additional ammo : With multiple ammo load carrying capacity, this tanker

can alone destroy multiple targets in the war. Since the main gun alone can’t fire missiles

back to back, installing 3 machine guns of long range can be beneficial in short range

attack and even to destroy multiple moving targets simultaneously.

5. Design and analysis : Further modifications in design and analysis can

make UGVs very powerful, durable and reliable with the advancement in technology in

future.

6. Material usage : By researching and developing a new material which can

withstand high collisions and are also not very heavy, the UGVs can made more resistible

to the land mines, hand granite, bazooka/man-portable missiles etc,.

7. High frequency receivers : By using the high frequency transmitter and

receiver, the UGVs can be operated from longer ranger say from about 10 miles away

from the controller.

The key to mastering unmanned warfare would include the complex tasks

of cross-selecting the technological components and integrating them into our military

hardware. The selected components should be seen as capabilities a country's armed

forces and defense industries must master, for they constitute the very essence of its

future fighting capabilities.

CONCLUSION

The project work is designed and developed successfully. For the demonstration

purpose, a prototype module is constructed; and the results are found to be satisfactory.

Since it is a prototype module, a simple war tanker is constructed, which can be used for

many applications. In this concept the warfare vehicle is controlled by a remote that will

be operated by the operator and also has the provision to operate automatically. The

triggering of the gun can also be done through the remote by which the gun sound

simulator IC produces the gun shot sensation.

The employment of unmanned platforms in the battlefield serves not only to

overcome the constraints arising from manpower and resource shortages, but also

increases the operational capability of a fighting force. They will provide tangible

increases in combat range, firepower, speed, element of surprise, command and control,

etc. As unmanned warfare and the mastery of unmanned technology will become

increasingly important parts of a nation's strategic architecture, here armed forces and

defense industries will need to pay appropriate attention to this aspect of warfare.

While designing and developing this proto type module, we have consulted few

experts those who are having knowledge in Mechatronics, and these professionals

working at different organizations belongs to Hyderabad helped us while fabricating this

project work. Since it is a prototype module, much amount is not invested. The whole

machine is constructed with locally available components, especially the mechanical

components used in this project work are procured from mechanical fabricators and they

are not exactly up to the requirement. Some of the modifications must be carried out in

design to make it as real working system.

REFERENCES:

The following are the references made during the development of this project

work.

Text Books:

1. Mechatronics – Electronic Control Systems in Mechanical and electrical Engineering

– By: W. Bolton

2. Mechatronics – By HMT Limited

3. Mechanism and Machine Theory By: J.S. Rao, R.V. Dukkipati

4. Industrial Robotics – Technology, Programming, & Applications. By: MIKELL P.

GROOVER, MITCHELL WEISS, ROGER

5. Electronic Circuit guide book – Sensors – By JOSEPH J.CARR

6. Linear Integrated Circuits – By: D. Roy Choudhury, Shail Jain

7. The concepts and Features of Micro-controllers - By: Raj Kamal

8. The 8051 Micro-controller Architecture, programming & Applications - By: Kenneth

J. Ayala

9. Programming and Customizing the 8051 Micro-controller - By: Myke Predko

10. The IC 555 Timer Applications Source book - By: HOWARD M. BERLIN

Catalogs:

1. TEXAS - LINEAR IC’s manual

2. SIGNETICS - DIGITAL IC’s manual

Web Links :

1. http://www.precisionmicrodrives.com/

2. http://en.wikipedia.org/wiki/Tank_destroyer

3. http://en.wikipedia.org/wiki/Future_Combat_Systems_manned_ground_vehicles#Mo

unted_combat_system

4. http://www.defense-update.com/features/du-1-04/feature-armor-protection.htm

5. http://www.armedforces-

int.com/news/electrified_vehicle_armour_could_deflect_weapons.html