CHINMAYA INSTITUTE OF TECHNOLOGY

KANNUR

SEMINAR REPORT

On

Auto-pilot

Presented by

Rihesh Raveendran

4thsem MCA

SCHOOL OF COMPUTER SCIENCE

AND

INFORMATION TECHNOLOGY

CHINMAYA INSTITUTE OF TECHNOLOGY

KANNUR

SCHOOL OF COMPUTER SCIENCE AND INFORMATION TECHNOLOGY

DECLARATION

I Rincy Ranjith, 4th Semester MCA, student of

Chinmaya Institute of Technology, do hereby declare that the Seminar Report

entitled

“Palm Vein Technology” is the original work carried out by me under the supervision of

Mr.Bimal v o towards partial fulfillment of the requirement of MCA Degree.

Signature of the Student

Kannur :

Date :

CHINMAYA INSTITUTE OF TECHNOLOGY

KANNUR

SCHOOL OF COMPUTER SCIENCE AND INFORMATION TECHNOLOGY

CERTIFICATE

This is to certify that the Seminar Report titled “Palm Vein Technology”

was prepared and presented by Rincy Ranjith of the School of Computer Science

and Information Technology, Chinmaya Institute of Technology in partial

fulfillment of the requirement as a subject under the University of Kannur during

the 4th Semester.

Faculty in Charge

Kannur :

Date :

ACKNOWLEDGEMENT

Before i get into thick things i would like to add a few heartfelt words for the

people who gave unending support right from the stage the idea of the seminar

was

conceived. I express my deep sense of gratitude and sincere thanks to those who have helped

me in doing this seminar.

I express my sincere gratitude to Dr.K.K.Falgunan, Principal, Chinmaya Institute of

Technology, my seminar guide Mr.Bimal v o, faculty guide, Chinmaya Institute of

Technology,and all other teachers in the Department, for their encouragement throughout

this study.

I am deeply indebted to almighty god for being with me during the conduct of this seminar

and helping me for the successful completion of the same.

Rincy Ranjith

4th Semester MCA

Place:

Date:

INTRODUCTION

Automatic pilots, or autopilots, are devices for controlling spacecraft, aircraft, watercraft,

missiles and vehicles without constant human intervention . An autopilot can refer specifically to

aircraft, self-steering gear for boats, or auto guidance of space craft and missiles. The autopilot of

an aircraft is sometimes referred to as "George", after one of the key contributors to its

development

Human flight has become a tired fact of modern life. At any given moment, roughly 5,000

airplanes crisscross the skies above the United States alone, amounting to an estimated 64 million

commercial and private takeoffs every year. Consider the rest of the world's flight activity, and the

grand total is incalculable.

It is easy to take the physics of flight for granted, as well as the ways in which we exploit

them to achieve flight. We often glimpse a plane in the sky with no greater understanding of the

principles involved than a caveman.

How do these heavy machines take to the air? To answer that question, we have to enter

the world of fluid mechanics.

Physicists classify both liquids and gases as fluids, based on how they flow. Even though

air, water and pancake syrup may seem like very different substances, they all conform to the

same set of mathematical relationships. In fact, basic aerodynamic tests are sometimes performed

underwater. To put it simply, a salmon essentially flies through the sea, and a pelican swims

through the air.

The core of the matter is this: Even a clear sky isn't empty. Our atmosphere is a massive

fluid layer, and the right application of physics makes it possible for humans to traverse it.

In this article, we'll walk through the basic principles of aviation and the various forces at

work in any given flight.

FIRST AUTOPILOT SYSTEM

In the early days of aviation, aircraft required the continuous attention of a pilot in order to

fly safely. As aircraft range increased allowing flights of many hours, the constant attention led to

serious fatigue. An autopilot is designed to perform some of the tasks of the pilot.

The first aircraft autopilot was developed by Sperry Corporation in 1912. The autopilot

connected a gyroscopic Heading indicator and attitude indicator to hydraulically operated

elevators and rudder (ailerons were not connected as wing dihedral was counted upon to produce

the necessary roll stability.) It permitted the aircraft to fly straight and level on a compass course

without a pilot's attention, greatly reducing the pilot's workload.

Lawrence Sperry (the son of famous inventor Elmer Sperry) demonstrated it two years

later in 1914 at an aviation safety contest held in Paris. At the contest, Sperry demonstrated the

credibility of the invention by flying the aircraft with his hands away from the controls and visible

to onlookers of the contest. This autopilot system was also capable of performing take-off and

landing, and the French military command showed immediate interest in the autopilot system.

Elmer Sperry Jr., the son of first gyro auto-pilot, Lawrence Sperry, and Capt Shiras continued

work after the war on the auto-pilot developed by Elmer Sperry's father, and in 1930 test a more

compact and reliable auto-pilot which kept a US Army Air Corps aircraft on a true heading and

altitude for three hours, that was probably of the type used by Wiley Post to fly alone around the

world in less than eight days in 1933.

In 1930 the Royal Aircraft Establishment in England developed an autopilot called a

pilots' assister that used a gyroscope and compressed air to move the flight controls.

Further development of the autopilot were performed, such as improved control algorithms

and hydraulic servomechanisms. Also, inclusion of additional instrumentation such as the radio-

navigation aids made it possible to fly during night and in bad weather. In 1947 a US Air Force C-

54 made a transatlantic flight, including takeoff and landing, completely under the control of an

autopilot.

In the early 1920s, the Standard Oil tanker J.A. Moffet became the first ship to use an

autopilot.

HOW AN AIRLINE PILOT WORKS

Flying an airplane is fun. Getting paid to do it is even better. For some people, it's the perfect

job: an office that travels, a view that's constantly changing and challenges that are exhilarating. It

has been said that a pilot's job is hours of boredom punctuated with seconds of sheer terror. This is

perhaps hyperbole, but sometimes not all that far from the truth.

A person who takes a multimillion dollar machine, casually flies it off the ground and then

safely returns it, fascinates people. They wonder what it's like to be responsible for hundreds of

lives or goods worth millions. When passengers peek inside a cockpit, they are amazed. They stare

at the multitude of dials and ask incredulously, "Do you really know what they all do?"

Pilots are the focal point and end operator in a huge team of highly trained professionals.

They are the movie stars of the air transportation show, because they are the most visible people to

the public, while most of the other team members remain "behind the scenes." But movie stars

rarely die or cause others to die because of an on-the-job mistake. All pilots run that risk. Piloting

is a serious business.

HOW DO PLANES FLY: THRUST AND DRAG

Drop a stone into the ocean and it will sink into the deep. Chuck a stone off the side of a

mountain and it will plummet as well. Sure, steel ships can float and even very heavy airplanes can

fly, but to achieve flight, you have to exploit the four basic aerodynamic forces: lift, weight, thrust

and drag. You can think of them as four arms holding the plane in the air, each pushing from a

different direction.

First, let's examine thrust and drag. Thrust, whether caused by a propeller or a jet engine,

is the aerodynamic force that pushes or pulls the airplane forward through space. The opposing

aerodynamic force is drag, or the friction that resists the motion of an object moving through a

fluid (or immobile in a moving fluid, as occurs when you fly a kite).

If you stick your hand out of a car window while moving, you'll experience a very simple

demonstration of drag at work. The amount of drag that your hand creates depends on a few

factors, such as the size of your hand, the speed of the car and the density of the air. If you were to

slow down, you would notice that the drag on your hand would decrease.

We see another example of drag reduction when we watch downhill skiers in the Olympics.

Whenever they get the chance, they'll squeeze down into a tight crouch. By making themselves

"smaller," they decrease the drag they create, which allows them to zip faster down the hill.

A passenger jet always retracts its landing gear after takeoff for a similar reason: to reduce

drag. Just like the downhill skier, the pilot wants to make the aircraft as small as possible. The

amount of drag produced by the landing gear of a jet is so great that, at cruising speeds, the gear

would be ripped right off the plane.

For flight to take place, thrust must be equal to or greater than the drag. If, for any reason,

the amount of drag becomes larger than the amount of thrust, the plane will slow down. If the

thrust is increased so that it's greater than the drag, the plane will speed up.

HOW DO AIRPLANES FLY: WEIGHT AND LIFT

Every object on Earth has weight, a product of both gravity and mass. A Boeing 747-8

passenger airliner, for instance, has a maximum takeoff weight of 487.5 tons (442 metric tons), the

force with which the weighty plane is drawn toward the Earth.

Weight's opposing force is lift, which holds an airplane in the air. This feat is accomplished

through the use of a wing, also known as an airfoil. Like drag, lift can exist only in the presence of

a moving fluid. It doesn't matter if the object is stationary and the fluid is moving (as with a kite

on a windy day), or if the fluid is still and the object is moving through it (as with a soaring jet on

a windless day). What really matters is the relative difference in speeds between the object and the

fluid.

As for the actual mechanics of lift, the force occurs when a moving fluid is deflected by a

solid object. The wing splits the airflow in two directions: up and over the wing and down along

the underside of the wing.

The wing is shaped and tilted so that the air moving over it travels faster than the air

moving underneath. When moving air flows over an object and encounters an obstacle (such as a

bump or a sudden increase in wing angle), its path narrows and the flow speeds up as all the

molecules rush though. Once past the obstacle, the path widens and the flow slows down again. If

you've ever pinched a water hose, you've observed this very principle in action. By pinching the

hose, you narrow the path of the fluid flow, which speeds up the molecules. Remove the pressure

and the water flow returns to its previous state.

As air speeds up, its pressure drops. So the faster-moving air moving over the wing exerts

less pressure on it than the slower air moving underneath the wing. The result is an upward push of

lift. In the field of fluid dynamics, this is known as Bernoulli's principle

AERIAL NAVIGATION: WINGS, SLATS AND FLAPS

Having covered the basic physics of flight and the ways in which an airplane uses them to

fly, the next obvious step is to consider navigation. How does an airplane turn in the air? How

does it rise to a higher altitude or dive back toward the ground?

First, let's consider the angle of attack, the angle that a wing (or airfoil) presents to

oncoming air. The greater the angle of attack, the greater the lift. The smaller the angle, the less

lift. Interestingly enough, it's actually easier for an airplane to climb than it is to travel at a fixed

altitude. A typical wing has to present a negative angle of attack (slanted forward) in order to

achieve zero lift. This wing positioning also generates more drag, which requires greater thrust.

In general, the wings on most planes are designed to provide an appropriate amount of lift

(along with minimal drag) while the plane is operating in its cruising mode. However, when these

airplanes are taking off or landing, their speeds can be reduced to less than 200 miles per hour

(322 kilometers per hour). This dramatic change in the wing's working conditions means that a

different airfoil shape would probably better serve the aircraft. Airfoil shapes vary depending on

the aircraft, but pilots further alter the shape of the airfoil in real time via flaps and slats.

During takeoff and landing, the flaps (on the back of the wing) extend downward from the

trailing edge of the wings. This effectively alters the shape of the wing, allowing it to divert more

air, and thus create more lift. The alteration also increases drag, which helps a landing airplane

slow down (but necessitates more thrust during takeoff).

Slats perform the same function as flaps (that is, they temporarily alter the shape of the

wing to increase lift), but they're attached to the front of the wing instead of the rear. Pilots also

deploy them on takeoff and landing.

Pilots have to do more than guide a plane through takeoff and landing though. They have

to steer it through the skies, and airfoils and their flaps can help with that, too.

AERIAL NAVIGATION: STABILIZERS, AILERONS, RUDDERS AND ELEVATORS

The tail of the airplane has two types of small wings, called the horizontal and vertical

stabilizers. A pilot uses these surfaces to control the direction of the plane. Both types of stabilizer

are symmetrical airfoils, and both have large flaps to alter airflow.

On the horizontal tail wing, these flaps are called elevators as they enable the plane to go

up and down through the air. The flaps change the horizontal stabilizer's angle of attack, and the

resulting lift either raises the rear of the aircraft (pointing the nose down) or lowers it (pointing the

nose skyward).

Meanwhile, the vertical tail wing features a flap known as a rudder. Just like its nautical

counterpart on a boat, this key part enables the plane to turn left or right and works along the same

principle.

Finally, we come to the ailerons, horizontal flaps located near the end of an airplane's

wings. These flaps allow one wing to generate more lift than the other, resulting in a rolling

motion that allows the plane to bank left or right. Ailerons usually work in opposition. As the right

aileron deflects upward, the left deflects downward, and vice versa. Some larger aircraft, such as

airliners, also achieve this maneuver via deployable plates called spoilers that raise up from the

top center of the wing.

By manipulating these varied wing flaps, a pilot maneuvers the aircraft through the sky.

They represent the basics behind everything from a new pilot's first flight to high-speed dogfights

and supersonic, hemisphere-spanning jaunts.

COMMUNICATION IN THE SKIES

At the very beginning of this article, we discussed the thousands upon thousands of aircraft

that fill the sky regularly. How do they avoid crashing into each other and landing without

unleashing absolute chaos? Well, we have the field of avionics to thank.

Avionics entails all of an aircraft's electronic flight control systems: communications gear,

navigation system, collision avoidance and meteorological systems. An overarching aerospace and

air traffic control system ensures the safety of commercial and private aircraft as they take off,

land and traverse vast distances without incident. Through the use of radar, computerized flight

plans and steady communication, air traffic controllers ensure planes operate at safe distances

from each other and redirect them around bad weather.

Needless to say, global air traffic control is a colossal task. It essentially involves

governance of the skies, so we tackle that operation similarly to how we would on the ground: We

divide things up. U.S. airspace, for example, breaks down into 21 air route traffic control centers

(ARTCCs), each a designated territory that spans whole states and more. Internationally, you'll

also hear these airspaces called area control centers (ACCs). Depending on a country's size, they

may employ one or several ACCs.

If a flight takes a plane across several countries, it passes through various ACCs, each

monitored by different air traffic controllers who give instructions to the pilot as needed. If a flight

takes a plane into international airspace (the air above international waters), the crew will still

depend on the assistance of an ACC, though the ground controllers may have to forgo the use of

radar and depend on pilot reports and computer models.

AUTOPILOTS AND AVIONICS

Automatic pilots, or autopilots, are devices for controlling , ,spacecraft watercraft, missiles

and vehicles without constant human intervention. Most people associate autopilots with aircraft,

so that's what we'll emphasize in this article. The same principles, however, apply to autopilots

that control any kind of vessel.

In the world of aircraft, the autopilot is more accurately described as the automatic flight

control system (AFCS). An AFCS is part of an aircraft's avionics -- the electronic systems,

equipment and devices used to control key systems of the plane and its flight. In addition to flight

control systems, avionics include electronics for communications, navigation, collision avoidance

and weather. The original use of an AFCS was to provide pilot relief during tedious stages of

flight, such as high-altitude cruising. Advanced autopilots can do much more, carrying out even

highly precise maneuvers, such as landing an aircraft in conditions of zero visibility.

Although there is great diversity in autopilot systems, most can be classified according to

the number of parts, or surfaces, they control. To understand this discussion, it helps to be familiar

with the three basic control surfaces that affect an airplane's attitude. The first are the elevators,

which are devices on the tail of a plane that control pitch (the swaying of an aircraft around a

horizontal axis perpendicular to the direction of motion). The rudder is also located on the tail of

a plane. When the rudder is tilted to starboard (right), the aircraft yaws -- twists on a vertical axis

-- in that direction. When the rudder is tilted to port (left), the craft yaws in the opposite direction.

Finally, ailerons on the rear edge of each wing roll the plane from side to side.

Autopilots can control any or all of these surfaces. A single-axis autopilot manages just

one set of controls, usually the ailerons. This simple type of autopilot is known as a "wing leveler"

because, by controlling roll, it keeps the aircraft wings on an even keel. A two-axis autopilot

manages elevators and ailerons. Finally, a three-axis autopilot manages all three basic control

systems: ailerons, elevators and rudder.

What are the basic parts of an autopilot that enable it to exert control over these surfaces?

We'll explore the answer to that question in the next section.

AUTOPILOT PARTS

The heart of a modern automatic flight control system is a computer with several high-

speed processors. To gather the intelligence required to control the plane, the processors

communicate with sensors located on the major control surfaces. They can also collect data from

other airplane systems and equipment, including gyroscopes, accelerometers, altimeters,

compasses and airspeed indicators.

The processors in the AFCS then take the input data and, using complex calculations,

compare it to a set of control modes. A control mode is a setting entered by the pilot that defines a

specific detail of the flight. For example, there is a control mode that defines how an aircraft's

altitude will be maintained. There are also control modes that maintain airspeed, heading and

flight path.

These calculations determine if the plane is obeying the commands set up in the control

modes. The processors then send signals to various servomechanism units. A servomechanism, or

servo for short, is a device that provides mechanical control at a distance. One servo exists for

each control surface included in the autopilot system. The servos take the computer's instructions

and use motors or hydraulics to move the craft's control surfaces, making sure the plane maintains

its proper course and attitude.

The above illustration shows how the basic elements of an autopilot system are related. For

simplicity, only one control surface -- the rudder -- is shown, although each control surface would

have a similar arrangement. Notice that the basic schematic of an autopilot looks like a loop, with

sensors sending data to the autopilot computer, which processes the information and transmits

signals to the servo, which moves the control surface, which changes the attitude of the plane,

which creates a new data set in the sensors, which starts the whole process again. This type of

feedback loop is central to the operation of autopilot systems. It's so important that we're going to

examine how feedback loops work in the next section.

AUTOPILOT CONTROL SYSTEMS

An autopilot is an example of a control system. Control systems apply an action based on

a measurement and almost always have an impact on the value they are measuring. A classic

example of a control system is the negative feedback loop that controls the thermostat in your

home. Such a loop works like this:

1. It's summertime, and a homeowner sets his thermostat to a desired room temperature -- say

78°F.

2. The thermostat measures the air temperature and compares it to the preset value.

3. Over time, the hot air outside the house will elevate the temperature inside the house.

When the temperature inside exceeds 78°F, the thermostat sends a signal to the air

conditioning unit.

4. The air conditioning unit clicks on and cools the room.

5. When the temperature in the room returns to 78°F, another signal is sent to the air

conditioner, which shuts off.

It's called a negative feedback loop because the result of a certain action (the air

conditioning unit clicking on) inhibits further performance of that action. All negative feedback

loops require a receptor, a control center and an effector. In the example above, the receptor is

the thermometer that measures air temperature. The control center is the processor inside the

thermostat. And the effector is the air conditioning unit.

Automated flight control systems work the same way. Let's consider the example of a pilot

who has activated a single-axis autopilot -- the so-called wing leveler we mentioned earlier.

1. The pilot sets a control mode to maintain the wings in a level position.

2. However, even in the smoothest air, a wing will eventually dip.

3. Position sensors on the wing detect this deflection and send a signal to the autopilot

computer.

4. The autopilot computer processes the input data and determines that the wings are no

longer level.

5. The autopilot computer sends a signal to the servos that control the aircraft's ailerons. The

signal is a very specific command telling the servo to make a precise adjustment.

6. Each servo has a small electric motor fitted with a slip clutch that, through a bridle cable,

grips the aileron cable. When the cable moves, the control surfaces move accordingly.

7. As the ailerons are adjusted based on the input data, the wings move back toward level.

8. The autopilot computer removes the command when the position sensor on the wing

detects that the wings are once again level.

9. The servos cease to apply pressure on the aileron cables.

This loop, shown above in the block diagram, works continuously, many times a second,

much more quickly and smoothly than a human pilot could. Two- and three-axis autopilots obey

the same principles, employing multiple processors that control multiple surfaces. Some airplanes

even have autothrust computers to control engine thrust. Autopilot and autothrust systems can

work together to perform very complex maneuvers.

AUTOPILOT FAILURE

Autopilots can and do fail. A common problem is some kind of servo failure, either

because of a bad motor or a bad connection. A position sensor can also fail, resulting in a loss of

input data to the autopilot computer. Fortunately, autopilots for manned aircraft are designed as a

failsafe -- that is, no failure in the automatic pilot can prevent effective employment of manual

override. To override the autopilot, a crew member simply has to disengage the system, either by

flipping a power switch or, if that doesn't work, by pulling the autopilot circuit breaker.

Some airplane crashes have been blamed on situations where pilots have failed to

disengage the automatic flight control system. The pilots end up fighting the settings that the

autopilot is administering, unable to figure out why the plane won't do what they're asking it to do.

This is why flight instruction programs stress practicing for just such a scenario. Pilots must know

how to use every feature of an AFCS, but they must also know how to turn it off and fly without it.

They also have to adhere to a rigorous maintenance schedule to make sure all sensors and servos

are in good working order. Any adjustments or fixes in key systems may require that the autopilot

be tweaked. For example, a change made to gyro instruments will require realignment of the

settings in the autopilot's computer.

MODERN AUTOPILOT SYSTEMS

Many modern autopilots can receive data from a Global Positioning System (GPS)

receiver installed on the aircraft. A GPS receiver can determine a plane's position in space by

calculating its distance from three or more satellites in the GPS network. Armed with such

positioning information, an autopilot can do more than keep a plane straight and level -- it can

execute a flight plan.

Most commercial jets have had such capabilities for a while, but even smaller planes are

incorporating sophisticated autopilot systems. New Cessna 182s and 206s are leaving the factory

with the Garmin G1000 integrated cockpit, which includes a digital electronic autopilot combined

with a flight director. The Garmin G1000 delivers essentially all the capabilities and modes of a jet

avionics system, bringing true automatic flight control to a new generation of general aviation

planes.Wiley Post could have only dreamed of such technology back in 1933.

MODERN AUTOPILOT SYSTEM

Not all of the passenger aircraft flying today have an autopilot system. Older and smaller

general aviation aircraft especially are still hand-flown, and even small airliners with fewer than

twenty seats may also be without an autopilot as they are used on short-duration flights with two

pilots. The installation of autopilots in aircraft with more than twenty seats is generally made

mandatory by international aviation regulations. There are three levels of control in autopilots for

smaller aircraft. A single-axis autopilot controls an aircraft in the roll axis only; such autopilots are

also known colloquially as "wing levellers," reflecting their limitations. A two-axis autopilot

controls an aircraft in the pitch axis as well as roll, and may be little more than a "wing leveller"

with limited pitch oscillation-correcting ability; or it may receive inputs from on-board radio

navigation systems to provide true automatic flight guidance once the aircraft has taken off until

shortly before landing; or its capabilities may lie somewhere between these two extremes. A three-

axis autopilot adds control in the yaw axis and is not required in many small aircraft.

Autopilots in modern complex aircraft are three-axis and generally divide a flight into taxi,

takeoff, ascent, cruise (level flight), descent, approach, and landing phases. Autopilots exist that

automate all of these flight phases except the taxiing. An autopilot-controlled landing on a runway

and controlling the aircraft on rollout (i.e. keeping it on the centre of the runway) is known as a

CAT IIIb landing or Autoland, available on many major airports' runways today, especially at

airports subject to adverse weather phenomena such as fog. Landing, rollout, and taxi control to

the aircraft parking position is known as CAT IIIc. This is not used to date, but may be used in the

future. An autopilot is often an integral component of a Flight Management System.

Modern autopilots use softwarecomputer to control the aircraft. The software reads the

aircraft's current position, and then controls a Flight Control System to guide the aircraft. In such a

system, besides classic flight controls, many autopilots incorporate thrust control capabilities that

can control throttles to optimize the airspeed, and move fuel to different tanks to balance the

aircraft in an optimal attitude in the air. Although autopilots handle new or dangerous situations

inflexibly, they generally fly an aircraft with a lower fuel-consumption than a human pilot.

The autopilot in a modern large aircraft typically reads its position and the aircraft's attitude from

an inertial guidance system. Inertial guidance systems accumulate errors over time. They will

incorporate error reduction systems such as the carousel system that rotates once a minute so that

any errors are dissipated in different directions and have an overall nulling effect. Error in

gyroscopes is known as drift. This is due to physical properties within the system, be it mechanical

or laser guided, that corrupt positional data. The disagreements between the two are resolved with

digital signal processing, most often a six-dimensional Kalman filter. The six dimensions are

usually roll, pitch, yaw, altitude, latitude, and longitude. Aircraft may fly routes that have a

required performance factor, therefore the amount of error or actual performance factor must be

monitored in order to fly those particular routes. The longer the flight, the more error accumulates

within the system. Radio aids such as DME, DME updates, and GPS may be used to correct the

aircraft position.