my hal project
TRANSCRIPT
SUMMER TRAINING
REPORT
Hindustan Aeronautics Limited
Lucknow, U.P.(Duration: 25st June 2011 to 24th July 2011)
Submitted for partial fulfillment of the requirement for the award of the degree of
Bachelor of Technology
In
ELECTRONICS & INSTRUMENTATION ENGINEERING
SUBMITTED BY:
ABHISHEK PANDEY08EI02
Department of Electronics & Instrumentation Engineering,
I.E.T., M.J.P. Rohilkhand University,
Bareilly(U.P.)-243006
DECLARATION
I here by declare that project work is an authentic record of my own work carried out at
HINDUSTAN AERONAUTICS LIMITED, LUCKNOW as requirement of 4 weeks project
for the award of degree during 25th JUNE to 24th JULY, 2011.
ABHISHEK PANDEY
08EI02
M.J.P.R.U., BAREILLY
Certified that the above statement made by the student is correct to the best of our knowledge
and belief.
Sign._________
INSTITUTE OF ENGINEERING & TECHNOLOGY
M.J.P.ROHILKHAND UNIVERSITY
BAREILLY-243006
CERTIFICATE
CONCERN TO WHOM IT MAY
This is to certify that Mr. ABHISHEK PANDEY, ROLL NO. 08EI02, B.Tech. final year student of Electronics & Instrumentation Engineering had undergone an Industrial Training at “HINDUSTAN AERONAUTICS LTD.” Lucknow, effect 25-06-2011 TO 24-07-2011. He has appeared in the Industrial Training viva–vice as partial fulfillment of requirement for the award of degree in “Bachelor of Technology” in the Electronics & Instrumentation Engineering of M.J.P. Rohilkhand University, Bareilly during the Academic year 2011-12.
Mr. Yatendra Kumar
H.O.D.
(EI Deptt.)
ACKNOWLEDGEMENT
With deep sense of gratitude, first & foremost I express my
profound thanks to Mr. Manoj Kumar, Sr. Manager- Training for giving
me this very opportunity to do my summer training in the Instrument
factory of H.A.L. Lucknow during the summer session- 2011.
I would like to express my gratitude to Mr. Ram Awtar, Head of
Instrument factory, our training guide for the valuable guidance ,
inspiration & enouragenment.
Last but not the least, I also wish to acknowledge my indebteness
to the staff of H.A.L. without whose co-operation, this training would not
have not been successful.
The training at H.A.L. Lucknow was full of responsiveness & it
gave me the rare opportunity to correlate the theoretical knowledge with
the practical one.
Being well known company of India & abroad, it gave me the
opportunity to learn the work carried out here, got a glimpse of new
environment & hard work of industrial unit.
CONTENT
1. Preface
2. About H.A.L.
3. Organizational Growth of HAL
4. Our Products
5. The Organization
6. HAL services
7. Airplane parts definitions
8. Major products of the H.A.L. Division
9. H.A.L. Accessories Division - Lucknow
10. Instrument Factory
Clean room
Assembly and test shop 2 & 3
Electromagnetic rotating shop (E.R.M)
Ground land navigation system shop (G.L.N.S)
11. Gyroscope
Properties
12. Actuator
Mechanical actuators
Hydraulic actuators
Piezoelectric actuators
Electro-mechanical actuators
Linear Actuator
Trim Actuator
13. Flight Data Recorder
14. Advanced Light Helicopter (ALH)
15. Conclusion
16. References
PREFACE
Last few years have witnessed major changes in economic environment of
our country. The industrial and economical policies have been liberalized .Indian
industries have become globally competitive, giving boost to the young and small
enterprises and thus arises the need of an efficient research and development
department.
I had done my part of training in INSTRUMENT DEPARTMENT of HAL
LUCKNOW. The project I had worked on ALH department, SU30 department.
There I had learned a lot of things about Helicopter and Fighter plane.
This all, for me, was a memorable experience.
Hindustan Aeronautics Limited (HAL) came into existence on 1st
October 1964. The Company was formed by the merger of Hindustan
Aircraft Limited with Aeronautics India Limited and Aircraft Manufacturing
Depot, Kanpur.
The Company traces its roots to the pioneering efforts of an industrialist with
extraordinary vision, the late Seth Walchand Hirachand, who set up Hindustan
Aircraft Limited at Bangalore in association with the erstwhile princely State of
Mysore in December 1940. The Government of India became a shareholder in
March 1941 and took over the Management in 1942.
Today, HAL has 19 Production Units and 9 Research and Design Canters in 7
locations in India. The Company has an impressive product track record - 12 types
of aircraft manufactured with in-house R & D and 14 types produced under
license. HAL has manufactured over 3550 aircraft, 3600 engines and overhauled
over 8150 aircraft and 27300 engines.
HAL has been successful in numerous R & D programs developed for both
Defense and Civil Aviation sectors. HAL has made substantial progress in its
current projects:
Dhruv, which is Advanced Light Helicopter (ALH)
Tejas - Light Combat Aircraft (LCA)
Intermediate Jet Trainer (IJT)
Various military and civil upgrades.
Dhruv was delivered to the Indian Army, Navy, Air Force and the Coast
Guard in March 2002, in the very first year of its production, a unique
achievement.
HAL has played a significant role for India's space programs by participating in the
manufacture of structures for Satellite Launch Vehicles like
PSLV (Polar Satellite Launch Vehicle)
GSLV (Geo-synchronous Satellite Launch Vehicle)
IRS (Indian Remote Satellite)
INSAT (Indian National Satellite)
HAL has formed the following Joint Ventures (JVs):
BAeHAL Software Limited
Indo-Russian Aviation Limited (IRAL)
Snecma HAL Aerospace Pvt Ltd
SAMTEL HAL Display System Limited
HALBIT Avionics Pvt Ltd
HAL-Edgewood Technologies Pvt Ltd
INFOTECH HAL Ltd
Apart from these seven, other major diversification projects are Industrial Marine
Gas Turbine and Airport Services. Several Co-production and Joint Ventures with
international participation are under consideration.
HAL's supplies / services are mainly to Indian Defence Services, Coast Guards and
Border Security Forces. Transport Aircraft and Helicopters have also been supplied
to Airlines as well as State Governments of India. The Company has also achieved
a foothold in export in more than 30 countries, having demonstrated its quality and
price competitiveness.
HAL has won several International & National Awards for achievements in
R&D, Technology, Managerial Performance, Exports, Energy Conservation,
Quality and Fulfillment of Social Responsibilities.
HAL was awarded the “INTERNATIONAL GOLD MEDAL AWARD”
for Corporate Achievement in Quality and Efficiency at the International
Summit (Global Rating Leaders 2003), London, UK by M/s Global Rating
and UK in conjunction with the International Information and Marketing
Centre(IIMC).
HAL was presented the International - “ARCH OF EUROPE “Award in
Gold Category in recognition for its commitment to Quality, Leadership,
Technology and Innovation. At the National level, HAL won the "GOLD
excellence in Public Sector Management, instituted by the TROPHY" for
Standing Conference of Public Enterprises (SCOPE). The Company scaled
new heights in the financial year 2006-07 with a turnover of
Rs783.61Crores.
Su
30 MKI
Twin-seater, Multi-role, Long range Fighter / Bomber /
Air Superiority Aircraft
MiG-27 M
Single-seater Tactical Fighter / Bomber with variable sweep
wings
MiG-21 VARIANTS
Single-seater Front line Tactical Interceptor / Fighter
Aircraft
JAGUAR
Stabilized Inertial Platform with Dry-tuned Gyroscopes
and Accelerometers
AIRPLANE PARTS DEFINITIONS
And their functions
This page shows the parts of an airplane and their functions. Airplanes are
transportation devices which are designed to move people and cargo from one
place to another. Airplanes come in many different shapes and sizes depending on
the mission of the aircraft. The airplane shown on this slide is a turbine-powered
airliner which has been chosen as a representative aircraft.
For any airplane to fly, you must lift the weight of the airplane itself, the
fuel, the passengers, and the cargo. The wings generate most of the lift to hold the
plane in the air. To generate lift, the airplane must be pushed through the air. The
jet engines, which are located beneath the wings, provide the thrust to push the
airplane forward through the air. The air resists the motion in the form of
aerodynamic drag. Some airplanes use propellers for the propulsion system instead
of jets.
To control and maneuver the aircraft, smaller wings are located at the tail of
the plane. The tail usually has a fixed horizontal piece (called the horizontal
stabilizer) and a fixed vertical piece (called the vertical stabilizer). The stabilizers'
job is to provide stability for the aircraft, to keep it flying straight. The vertical
stabilizer keeps the nose of the plane from swinging from side to side, while the
horizontal stabilizer prevents an up-and-down motion of the nose. (On the Wright
brother's first aircraft, the horizontal stabilizer was placed in front of the wings.
Such a configuration is called a canard after the French word for "duck").
At the rear of the wings and stabilizers are small moving sections that are
attached to the fixed sections by hinges. In the figure, these moving sections are
colored brown. Changing the rear portion of a wing will change the amount of
force that the wing produces. The ability to change forces gives us a means of
controlling and maneuvering the airplane. The hinged part of the vertical stabilizer
is called the rudder; it is used to deflect the tail to the left and right as viewed from
the front of the fuselage. The hinged part of the horizontal stabilizer is called the
elevator; it is used to deflect the tail up and down. The outboard hinged part of the
wing is called the aileron; it is used to roll the wings from side to side. Most
airliners can also be rolled from side to side by using the spoilers. Spoilers are
small plates that are used to disrupt the flow over the wing and to change the
amount of force by decreasing the lift when the spoiler is deployed.
The wings have additional hinged, rear sections near the body that are called
flaps. Flaps are deployed downward on takeoff and landing to increase the amount
of force produced by the wing. On some aircraft, the front part of the wing will
also deflect. Slats are used at takeoff and landing to produce additional force. The
spoilers are also used during landing to slow the plane down and to counteract the
flaps when the aircraft is on the ground. The next time you fly on an airplane,
notice how the wing shape changes during takeoff and landing.
The fuselage or body of the airplane, holds all the pieces together. The pilots
sit in the cockpit at the front of the fuselage. Passengers and cargo are carried in
the rear of the fuselage. Some aircraft carry fuel in the fuselage; others carry the
fuel in the wings.
As mentioned above, the aircraft configuration in the figure was chosen only
as an example. Individual aircraft may be configured quite differently from this
airliner. The Wright Brothers 1903 Flyer had pusher propellers and the elevators at
the front of the aircraft. Fighter aircraft often have the jet engines buried inside the
fuselage instead of in pods hung beneath the wings. Many fighter aircraft also
combine the horizontal stabilizer and elevator into a single stipulator surface.
There are many possible aircraft configurations, but any configuration must
provide for the four forces needed for flight.
Aircraft Yaw Motion
In flight, any aircraft will rotate about its center of gravity, a point which is the
average location of the mass of the aircraft. We can define a three dimensional
coordinate system through the center of gravity with each axis of this coordinate
system perpendicular to the other two axes. We can then define the orientation of
the aircraft by the amount of rotation of the parts of the aircraft along these
principal axes. The yaw axis is perpendicular to the wings and lies in the plane of
the aircraft centerline. A yaw motion is a side to side movement of the nose of the
aircraft as shown in the animation.
The yawing motion is being caused by the deflection of the rudder of this
aircraft. The rudder is a hinged section at the rear of the vertical stabilizer.
As described on the shape effects slide, changing the angle of deflection at
the rear of an airfoil changes the amount of lift generated by the foil. For the
vertical stabilizer and rudder, the orientation of the airfoil causes a side force to be
generated. With greater deflection of the rudder to the left, the side force increases
to the right. With greater deflection to the right, the side force increases to the left.
The lift generated by the rudder acts through the center of pressure of the rudder
and vertical stabilizer and is located at some distance from the center of gravity of
the aircraft. The change in side force created by deflecting the rudder generates a
torque about the center of gravity which causes the airplane to rotate. The pilot
uses this ability to keep the nose of the aircraft pointed in the direction of travel.
On all aircraft, the vertical stabilizer and rudder create a symmetric airfoil.
This produces no side force when the rudder is aligned with the stabilizer and
allows the combination to produce either positive or negative side force, depending
on the deflection of the rudder. Some fighter planes have two vertical stabilizers
and rudders because of the need to control the plane with multiple, very powerful
engines
Aircraft Roll Motion
.
In flight, any aircraft will rotate about its center of gravity, a point which is the
average location of the mass of the aircraft. We can define a three dimensional
coordinate system through the center of gravity with each axis of this coordinate
system perpendicular to the other two axes. We can then define the orientation of
the aircraft by the amount of rotation of the parts of the aircraft along these
principal axes. The roll axis lies along the aircraft centerline. A roll motion is an up
and down movement of the wings of the aircraft as shown in the animation .
The rolling motion is being caused by the deflection of the ailerons of this
aircraft. The aileron is a hinged section at the rear of each wing. The ailerons work
in opposition; when the right aileron goes up, the left aileron goes down.
As described on the shape effects slide, changing the angle of deflection at
the rear of an airfoil will change the amount of lift generated by the foil. With
greater downward deflection, the lift will increase in the upward direction; with
greater upward deflection, the lift will decrease in the upward direction. Since the
ailerons work in pairs, the lift on one wing increases as the lift on the opposite
wing decreases. Because the forces are not equal, there is a net twist, or torque
about the center of gravity and the aircraft rotates about the roll axis. The pilot can
use this ability to bank the aircraft which causes the airplane to turn.
On this page we have demonstrated an aircraft roll induced by movement of
the ailerons, but there are other ways to produce a rolling motion on an aircraft.
The Wright brothers used a method called wing warping. Their wings were wired
together in such a way that the outer panels of each wing could be twisted relative
to the inner panel. The twisting changed the local angle of attack of sections of the
wing which changed the lift being generated by that section. Unequal forces on the
wings caused the aircraft to roll. Many modern airliners use a spoiler to roll the
aircraft. A spoiler is a plate that is raised between the leading and trailing edges of
the wing. The spoiler effectively changes the shape of the airfoil, disrupts the flow
over the wing, and causes a section of the wing to decrease its lift. This produces
an unbalanced force with the other wing, which causes the roll. Airliners use
spoilers because spoilers can react more quickly than ailerons and require less
force to activate, but they always decrease the total amount of lift for the aircraft.
It's an interesting trade! You can tell whether an airliner is using spoilers or
ailerons by noticing where the moving part is located. At the trailing
edge, it's an aileron; between the leading and trailing edges, it's a spoiler.
(Now you can dazzle the person sitting next to you on the plane!)
MAJOR PRODUCTS OF THE H.A.L. DIVISION
The major products of the Division are:
Undercarriage systems
Wheels and Brake systems
Hydraulic Systems
Aircraft and Engine Fuel Systems
Panel Instruments (Barometric and gyroscopic)
Electric Power Generation and Control systems
Environmental control systems.
Flight Control Actuators
Ground Support Equipment and test Rigs.
Main Customers:
i. Indian Air Force, Army, Navy, Coast Guard, BSF
ii. Defence R&D Laboratories and Deptt of Space;
iii. Civil Aviation, State Govt., Ordnance Factories, Corporate Sectors;
iv. Flying Academies & Educational Institutions;
v. Airlines, Air Taxi, Air Cargo;
vi. Overseas customers for civil and military applications.
vii. Collaborators and Licensors.
HAL ACCESSORIES DIVISION - LUCKNOW
Hindustan Aeronautics Limited
Accessories Division
Lucknow 226 016
India
The Division was established in 1970 with the primary objective of manufacturing
systems and accessories for various aircraft, helicopters and engines with a view to
attain self-sufficiency in this field in the country. The Division started with the
manufacture of hydro-mechanical accessories and instruments under license for
Marut and Kiran aircraft. This was followed by license manufacture of accessories
for MiG-21 aircraft, Cheetah/Chetak helicopters, Dornier and other defense
applications. Additionally repair and overhaul of Lucknow manufactured
accessories as well as those fitted on directly purchased aircraft, such as Mirage
and Sea Harrier was undertaken. At present, it is manufacturing, repairing and
overhauling more than 800 different types of systems and accessories under
license. The range of items cover units for hydraulics, engine fuel system,
environment control system, pressurization system, gyroscopic instruments,
barometric instruments, electrical system items, undercarriages, and electronic
items. The number of licensors exceeds twenty.
From inception, the Division has laid emphasis on developing indigenous
capability through design and development of various systems and accessories.
This capability has culminated in indigenous design and development of a variety
of systems and accessories for the Light Combat Aircraft (LCA), Advanced Light
Helicopter (all versions i.e. Army, Air force, Navy & Civil) and Intermediate Jet
Trainer (IJT-36). The Division has also developed and has made successful strides
into the area of Microprocessor based control systems. Design and Development
capabilities include Environmental Control Systems & Pneumatics, Fuel
Management, Engine Fuel Control & aircraft fuel systems, Microprocessor based
Controllers, Hydraulic System & Power Controls, Wheels and Brakes, Cockpit
instruments and sensors, Gyroscopes, Electrical Power Control Protection,
Navigation and Display, Land Navigation, Ground support equipment, Dedicated
Test rigs, and Computerized test equipment. The Division has diversified in other
defence applications like tanks and armored vehicles for Army, and took
commercial applications of Hydraulic items, Gyroscopic Equipment, Special
Purpose Test Equipment & Ground Support Equipment.
The Division has also made steady progress in the area of Exports. The range
of products and services available for exports include:
1. Rotables and spares of Jaguar International and Cheetah (Lama), Chetak
(Alouette) Helicopters;
2. Ground Support Equipment for MiG 23, 27, 29 Mirage-2000, Jaguar, LCA, Su-
30, Sea-Harrier, Dornier DO-228, Avro HS-748, Cheetah, Chetak, MI-17, and
ALH.
3. Repair and Overhaul of aircraft accessories of MiG series, Jaguar International,
Cheetah (Lama), Chetak (Alouette) and Dornier.
The Division today has a prime name in the aviation world and a number of
international companies are interested to join hands with it for future projects.
H.A.L. accessory division, Luknow is divided into three main factories namely
1. Mechanical Factory
2. Instrument Factory
3.FuelFactory
INSTRUMENT FACTORY
This factory deals with the testing and assembly of electronics instruments used in
aircraft e.g. Altimeter, RMI, Gyro-magnetic compass , black box etc.
This INSTRUMENT FACTORY is further divided into four units which are as
follows:
CLEAN ROOMS
ASSEMBLY AND TEST SHOP 2 & 3
ELECTRO ROTATING MACHINES
GROUND LAND NAVIGATION SYSTEM SHOP (G.L.N.S Shop)
Clean room
In Clean room those subunits are assembled and tested that are sensitive to
dust, temperature and humidity. All these parameters are kept under control
because these can have adverse effect on their functional efficiency.
The required specification for the instruments assembled and tested are
different .so Clean room is further subdivided into three units. The following chart
is given for the classification of clean room.
STANDARD CLEAN ROOM CONDITIONS:
ROO
M
ITEM
Temp
Limit
s °C
Humidit
y R/H %
Dust Count
Particle size 0.5
m/ft3
AIRCRAFT
ROOM
1
ROOM
2
Gyroscopic
Instruments of
Russian Origin
Barometric
Instruments,
Accelerometers
, RPM
Indicator of
Western
Origin
Gyroscopic
Instruments of
Western Origin
15 to
25
° C
15 to
25
° C
45 -55
45 -55
45 -55
<100,000
CLASS C –
UNMONITORE
D
<100,000
CLASS B
MIG 21, 27, AN
– 32
Kiran MK-I&II,
HPT-32, Jaguar,
AN-32, Mirage,
Dornier, Avro
Aircraft,
Cheetah,
Chetak, ALH
Helicopters
Kiran MK-I&II,
HPT-32, Jaguar,
AN-32, Mirage,
ROOM
3
15 to
25 ° C
<10,000
CLASS A -
MONITORED
Dornier, Avro
Aircraft,Lakshy
a, Cheetah,
Chetak
Helicopters
Assembly and test shop 2 & 3
The major products of H.A.L. are fighter aircrafts. An aircraft comprises of
many small units or accessories, which play significant role in their successful
flight. any fault, may lead to an catastrophic end. Here comes the role of assembly
and test unit .it forms an integral part of any manufacturing unit. The main
instrument were KCN-2 compass system, flight data recorder, gyro magnetic
compass, fuel gauging system, radio magnetic indicator, milli voltmeter
temperature indicator.
Electromagnetic rotating shop (E.R.M)
In the E.R.M department of the instrument factory the assembly and testing
of the dc Starter Generators, AC Generator system, Constant speed alternator,
Regulators, Inverter, of the Russian and French origin. These products are
basically those products which takes the principle of the electromagnetic rotating
which can be elaborated as follows i.e., electrical energy is converted into
mechanical energy or vice versa. These products are of mig-21 & mig-27 aircrafts
which is of Russian origin and jaguar aircraft is of France origin.
Ground land navigation system shop (G.L.N.S)
Ground land navigation system shop is one of the most different & unique
shop. As in this shop it manufacture the only ground land navigation system in
world. As due the different applicability of the gyros therefore these gyro own
s have been placed in the road transportation system which is used in ground e.g.
trucks, cars. The instrument which uses the property of any type of gyro and is
installed in road transportation system is known as ground land navigation system.
The Gyro land navigation system is an electronic navigation device used for
guiding any army vehicle to its destination point. The principle objective of system
is not only to ease the in more precise and quicker manner whether in plains, hills
or sand dunes, where there are no special remarks. In the G.L.N.S shop it
assembles and test the ground land navigation system of Vijayanta tank .
Gyroscope
A gyroscope is a device for measuring or maintaining orientation, based on
the principles of momentum. The device is a spinning wheel or disk whose axle is
free to take any orientation. This orientation changes much less in response to a
given external torque than it would without the large angular momentum
associated with the gyroscope's high rate of spin. Since external torque is
minimized by mounting the device in gimbals, its orientation remains nearly fixed,
regardless of any motion of the platform on which it is mounted. Gyroscope works
in situations when using magnetic compass is not possible at all (as in Hubble
telescope). Due to higher precision it is used to maintain direction in tunnel
mining.
Description
Within mechanical systems or devices, a conventional gyroscope is a
mechanism comprising a rotor journal to spin about one axis, the journals of the
rotor being mounted in an inner gimbals or ring, the inner gimbals’ being journal
for oscillation in an outer gimbals which in turn is journal for oscillation relative to
a support. The outer gimbals or ring is mounted so as to pivot about an axis in its
own plane determined by the support. The outer gimbals’ possesses one degree of
rotational freedom and its axis possesses none. The inner gimbals are mounted in
the outer gimbals’ so as to pivot about an axis in its own plane that is always
perpendicular to the pivotal axis of the outer gimbals’.
The axle of the spinning wheel defines the spin axis. The inner gimbals
possess two degrees of rotational freedom and its axis possesses one. The rotor is
journal to spin about an axis which is always perpendicular to the axis of the inner
gimbals’. So, the rotor possesses three degrees of rotational freedom and its axis
possesses two. The wheel responds to a force applied about the input axis by a
reaction force about the output axis.
The behavior of a gyroscope can be most easily appreciated by consideration
of the front wheel of a bicycle. If the wheel is leaned away from the vertical so that
the top of the wheel moves to the left, the forward rim of the wheel also turns to
the left. In other words, rotation on one axis of the turning wheel produces rotation
of the third axis.
A gyroscope flywheel will roll or resist about the output axis depending
upon whether the output gimbals are of a free- or fixed- configuration. Examples
of some free-output-gimbals’ devices would be the attitude reference gyroscopes
used to sense or measure the pitch, roll and yaw attitude angles in a spacecraft or
aircraft. The center of gravity of the rotor can be in a fixed position. The rotor
simultaneously spins about one axis and is capable of oscillating about the two
other axes, and thus, except for its inherent resistance due to rotor spin, it is free to
turn in any direction about the fixed point. Some gyroscopes have mechanical
equivalents substituted for one or more of the elements, e.g., the spinning rotor
may be suspended in a fluid, instead of being pivotally mounted in gimbals. A
control moment gyroscope (CMG) is an example of a fixed-output-gimbals device
that is used on spacecraft to hold or maintain a desired attitude angle or pointing
direction using the gyroscopic resistance force. In some special cases, the outer
gimbals (or its equivalent) may be omitted so that the rotor has only two degrees of
freedom. In other cases, the center of gravity of the rotor may be offset from the
axis of oscillation, and thus the center of gravity of the rotor and the center of
suspension of the rotor may not coincide.
Properties
A gyroscope exhibits a number of behaviors including precession and
mutation. Gyroscopes can be used to construct gyrocompasses which complement
or replace magnetic compasses (in ships, aircraft and spacecraft, vehicles in
general), to assist in stability (bicycle, Hubble Space Telescope, ships, vehicles in
general) or be used as part of an inertial guidance system. Gyroscopic effects are
used in toys like tops, yo-yos, and Powerball’s. Many other rotating devices, such
as flywheels, behave gyroscopically although the gyroscopic effect is not used.
The fundamental equation describing the behavior of the gyroscope is:
Where the vectors τ and L are, respectively, the torque on the gyroscope and
its angular momentum, the scalar I is its moment of inertia, the vector Ω is its
angular velocity, and the vector α is its angular acceleration. It follows from this
that a torque τ applied perpendicular to the axis of rotation, and therefore
perpendicular to L, results in a rotation about an axis perpendicular to both τ and L.
This motion is called precession. The angular velocity of precession ΩP is given by
the cross product:
Precession can be demonstrated by placing a spinning gyroscope with its
axis horizontal and supported loosely (frictionless toward precession) at one end.
Instead of falling, as might be expected, the gyroscope appears to defy gravity by
remaining with its axis horizontal, when the other end of the axis is left
unsupported and the free end of the axis slowly describes a circle in a horizontal
plane, the resulting precession turning. This effect is explained by the above
equations. The torque on the gyroscope is supplied by a couple of forces: gravity
acting downwards on the device's centre of mass, and an equal force acting
upwards to support one end of the device. The rotation resulting from this torque is
not downwards, as might be intuitively expected, causing the device to fall, but
perpendicular to both the gravitational torque (horizontal and perpendicular to the
axis of rotation) and the axis of rotation (horizontal and outwards from the point of
support), i.e. about a vertical axis, causing the device to rotate slowly about the
supporting point. Under a constant torque of magnitude τ, the gyroscope's speed of
precession ΩP is inversely proportional to L, the magnitude of its angular
momentum:
where θ is the angle between the vectors ΩP and L. Thus if the gyroscope's spin
slows down (for example, due to friction), its angular momentum decreases and so
the rate of precession increases. This continues until the device is unable to rotate
fast enough to support its own weight, when it stops processing and falls off its
support, mostly because friction against precession cause another precession that
goes to cause the fall.
By convention, these three vectors, torque, spin, and precession, are all
oriented with respect to each other according to the right-hand rule.
To easily ascertain the direction of gyro effect, simply remember that a
rolling wheel tends, when entering a corner, to turn over to the inside.
Actuator
A linear actuator is a device that applies force in a linear manner, as opposed
to rotationally like an electric motor. There are various methods of achieving this
linear motion. Some actually convert rotational motion into linear motion.
Types
Mechanical actuators
Mechanical actuators typically convert rotary motion of a control knob or
handle into linear displacement via screws and/or gears to which the knob or
handle is attached. A jackscrew or car jack is a familiar mechanical actuator.
Another family of actuators are based on the segmented spindle. Rotation of the
jack handle is converted mechanically into the linear motion of the jack head.
Mechanical actuators are also frequently used in the field of lasers and optics to
manipulate the position of linear stages, rotary stages, mirror mounts, monometers
and other positioning instruments. For accurate and repeatable positioning, index
marks may be used on control knobs. Some actuators even include an encoder and
digital position readout.[1] These are similar to the adjustment knobs used on
micrometers except that their purpose is position adjustment rather than position
measurement.
Hydraulic actuators
Hydraulic actuators or hydraulic cylinders typically involve a hollow
cylinder having a piston inserted in it. The two sides of the piston are alternately
pressurized/de-pressurized to achieve controlled precise linear displacement of the
piston and in turn the entity connected to the piston. The physical linear
displacement is only along the axis of the piston/cylinder. This design is based on
the principles of hydraulics. A familiar example of a manually operated hydraulic
actuator is a hydraulic car jack. Typically though, the term "hydraulic actuator"
refers to a device controlled by a hydraulic pump.
Piezoelectric actuators
The piezoelectric effect is a property of certain materials in which
application of a voltage to the material causes it to expand. Very high voltages
correspond to only tiny expansions. As a result, piezoelectric actuators can achieve
extremely fine positioning resolution, but also have a very short range of motion.
In addition, piezoelectric materials exhibit hysteresis which makes it difficult to
control their expansion in a repeatable manner.
Electro-mechanical actuators
Electro-mechanical actuators are similar to mechanical actuators except that
the control knob or handle is replaced with an electric motor. Rotary motion of the
motor is converted to linear displacement of the actuator. There are many designs
of modern linear actuators and every company that manufactures them tends to
have their own proprietary method. The following is a generalized description of a
very simple electro-mechanical linear actuator.
Linear Actuator
VL13A4Aircraft – Jaguar
The linear actuator VL13A4 is destined to operate the elevator trim. This actuator
is assembled with two motors and a differential planet gear arrangement which
converts the rotary motion of motor to linear motion. As the motors are
bidirectional it shows the progressive working in both the directions. For normal
working of the unit only, one motor is energized at a time. The second motor is
called the sub motor which works in case of failure of main motor.
Specifications
Nominal Load : 20 Dan
Maximum Load : 40 Dan
Operating Voltage : 18V to 29V
Stroke Length : 44+/-1.25mm
Motor RPM : 25000
Rated current : 0.85 Amp
Power : 5.2 Watt
Trim Actuator
Aircraft – ALH
A set of trim / force feel system(FFS) consists of four actuators namely collective,
pitch, roll and yaw actuator corresponding to the four body axis of the helicopter.
These actuators are electromechanical units interfaced with the mechanical as well
as with automatic flight control system. The conventional mechanical control
leakages in pitch, roll, collective and yaw axis are fitted with one corresponding
trim.
Functions
1.) Engagement/disengagement of anchor point by means of an
electrically operated clutch. This anchor point can be displaced
either automatically or mechanically.
2.) Artificial force feel about the anchor point generating a
predetermined feel force. The artificial feel is proportional to the
displacement in pitch, roll and collective trim actuator as they are
spring based. The force feel is a constant friction in the yaw axis.
3.) Pilot controlled displacement of the anchor point by means of an
electrical motor (manual trim function) or by declutching the
artificial feels.
4.) Automatic displacement of the anchor point so as to maintain the
series actuators around there centre position (auto trim) .
Flight Data Recorder
Purpose and working:
System records automatically 6 continuously changing parameters which are:
Altitude
Engine speed
Aircraft speed
Vertical acceleration
Horizontal acceleration
Turn Angle of stabilizer
Five single command signal, Eight single command signals superimposed on
Three continuously variable parameters, and timer line to indicate the time on
black and white aero photo film and preserves it in normal and crash conditions for
study and analysis of flight conditions.
Working:
In this, mechanical motion is converted into electrical signals and then it is
converted in to optical signals,. There is a fixed mirror in the vibrator which moves
accordingly to the moving light beam. The light beam is moved under the effect of
a permanent magnetic field and flux and shifts the light beam accordingly. Now
the mirror will move and thus light will move and thus further the photographic
film is printed.
ADVANCED LIGHT HELICOPTER (ALH)
Advanced Light Helicopter is a multirole, multimission helicopter designed
& developed by HAL. The design of this 5.5-ton class, twin-engine helicopter
incorporates several state of the art technologies. Extensive use of composites high
cruise speed, long range & endurance, excellent high altitude performance and
capability to operate in hot & humid environment are the key design features. ALH
has been designed for both civil & military applications in large variety of roles
overland & sea.
Performance:-
Maximum cruise speed at maximum load : 250 km/hr
Maximum rate of climb : 10 m/sec
Range with 20 min reserve : 650 km
Endurance : 4 hrs
Hover in ground effect : 1500 m
Hover out of ground effect : 1000m
Leading Particulars:-
Overall length : 15.87 m
Overall height : 4.91 m
Width : 3.19 m
Empty weight : 2500 kg
Fuel capacity : 1100 kg
Maximum take-off weight : 5500 kg
Maximum under slung weight : 1500 kg
Maximum height : 25000 HT
Roles:-
Military Role( unarmed):-
Heliborne attack
Reconnaissance
Logistics support
Casualty evacuation
Air observation post
Military Role (Armed):-
Anti tank
Close air support
Anti submarine warfare
Anti surface vessel warfare
Civil Role:-
Commuter / VIP
Search & rescue
Disaster relief
Air ambulance
Offshore operations
Salient Features:-
Ergonomically designed cockpit
Extensive use if composites, reduced radar signature
Large cabin volume
Ballistic damage tolerant
Greater system redundancy
Provision for weapons hard points
Twin engine with full authority digital electronic control
Adequate safety margin for single engine operation
Four axes automatic flying control system
Crash worthy crew seats, under floor & fuel tank
Hinge less main rotor & bearing less tail rotor
Excellent handling qualities at low as well as high speeds
Low maintenance cost & high fuel efficiency
CONCLUSION
Finally we may conclude that HAL Accessories Division, Lucknow is a
Government undertaking, which is entitled to perform the making of the
accessories used in the fighter aircraft.
Although the whole assembly of the aircraft is not done in HAL Lucknow
but there are plans to launch Sukhoi’s full assembly in HAL Lucknow
Thus HAL Lucknow would be entitled to work on latest technology of
Sukhoi aircraft in the coming future.
References
1. http://www.grc.nasa.gov/WWW/K-12/airplane/airplane.html
2. http://www.alibaba.com/countrysearch/IN-suppliers/Alternator_Manufacturers.html
3. http://en.wikipedia.org/wiki/Gyroscope
4. http://www.aircraftspruce.com/menus/ps/oxygensystems.html
5. en.wikipedia.org/wiki/Actuator
6. en.wikipedia.org/wiki/Voltage_regulator
Hindustan Aeronautics Limited
Accessories DivisionLucknow-226 016
India