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AUTOMATION IN HOWITZER
A MAJOR PROJECT REPORT
SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
AWARD OF
THE DEGREE OF
BACHELOR OF ENGINEERING
(Instrumentation & Control Engineering)
SUBMITTED TO
PUNE UNIVERSITY
SUBMITTED BY
Name of Student University Seat No.
Gunjal Gajanan B80784628
Bobhate Rohan B80784649
Kumbhare Prathmesh B80784632
GUIDED BY
Professor N.M. Karajanagi
HOD – Instrumentation & Control
May 2014
(Month & Year of Submission)
GOVERNMENT COLLEGE OF ENGINEERING AND RESEARCH
AWASARI (KHURD)
TABLE OF CONTENTS
Page No.
Acknowledgement i
Abstract ii
List of Tables iii
List of Figures iv
List of Abbreviations v
Page No.
Chapter 1: INTRODUCTION 1
Chapter 2: LITERATURE REVIEW 3
2.1 Howitzer introduction 3
2.2 Earlier firing methods 6
2.3 Projectile and shell types 12
2.4 Point mass model 18
2.5 Ballistics coefficient, Drag coefficient and Mach number 21
2.6 Fuzzy logic basics and fuzzy systems 26
Chapter 3: PRESENT WORK
3.1 Block diagram 31
3.2 MATLAB algorithm 32
3.3 Hardware implementation for the project 40
Chapter 4: Results And Discussion 43
Chapter 5: Conclusion And Future Scope 46
References 47
iii
List of Tables
Table Title Page
1 Various types of projectile 13
2 Types of shells & its uses 17
iv
LIST OF FIGURES
Figure Title Page
1 HOWITZER image 5
2 Drag coefficient 22
3 Mach number 25
4 Steps in fuzzy system 30
5 Block diagram of model 31
6 Fuzzy Toolbox 36
7 Actual signal conditioning 39
8 Model of HOWITZER 41
9 Firing table of 155mm projectile 44
v
ABBREVIATION
FO Forward observer
FDC Fire direction center
BRL Ballistics research laboratory
ii
Abstract
Howitzer cannons form a vital part in the war artillery in modern defense of our country. The
firing techniques employed in the past were time consuming and a bit tedious. With the
introduction of modern technologies this process has been considerably improved with
increased accuracy. This project report introduces another novel approach towards the firing
technique of Howitzer cannons. This approach demonstrates increased simplicity in designing
of firing algorithm and also improvement in the time required for firing. Another important
point worth mentioning is this report mainly dwells on the software algorithm developed for the
firing process and gives the mechanical part (hardware) secondary importance. The algorithm
which has been constructed finds its roots in the fuzzy logic. The firing process becomes
relatively easier as the fuzzy logic dictates this algorithm. Computation speed increases and so
ultimately the rate of firing improve. Incorporation of software was necessary; the algorithm
takes help of MATLAB for fuzzy logic implementation and MULTISIM for electrical circuits.
The hardware part (model) is a miniature of Howitzer cannon which is capable of both the
movements i.e. the vertical and horizontal rotation. Our model utilizes the pneumatic energy to
power the firing projectile. Projectile motion is an active research area and its accuracy is
constantly improving but for the sake of simplicity point mass model differential equations and
its assumptions were considered. In the latter stages of the report the readings and calculations
of the trajectories are included and finally possible future additions are mentioned.
ACKNOWLEDGEMENT
I would like to place on record my deep sense of gratitude to Prof. N.P. Futane HOD-Dept. of
Electronics & Telecommunications Engineering,. Government College Of Engineering And
Research, Awasari(Khurd), for his generous guidance, help and useful suggestions.
I express my sincere gratitude to Prof N.M. Karajanagi HOD-Dept. ofInstrumentation & Control
Engineering, Government College Of Engineering And Research, Awasari(Khurd), for his
stimulating guidance, continuous encouragement and supervision throughout the course of present
work.
I also wish to extend my thanks to Prof. N.P. Wagh and other colleagues for attending my seminars
and for their insightful comments and constructive suggestions to improve the quality of this
project work.
Signature(s) of Students
~n Kumbhare Prathrnesh
Gunjal Gajanan
(B80784628) (B80784649) (B80784632)
CERTIFICATE
I hereby certify that the work which is being presented in the B.E. Major Project Report entitled
"AUTOMATION IN HOWITZER", in partial fulfillment of the requirements for the award of
the Bachelor of Engineering in Instrumentation & Control Engineering and submitted to the
Department of Instrumentation & Control Engineering of Government College of Engineering
& Research,Awasari (Khurd) is an authentic record of my own work carried out during a period
from July 2013 to June 2014 under the supervision of Prof. N.M. Karajanagi, HOD-
Instrumentation & Control Department.
The matter presented in this Project Report has not been submitted by me for the award of
any other degree elsewhere.
~.
Gunjal Gajanan
(880784628)
Signature ofStudent
B£:(880784649)
Kumbhare Prathmesh
(880784632)
This is to certify that the above statement made by the student(s) is correct to the best of my
knowledge.
Signature of
External Examiner
Signature of
Principal
Prof. .
Project Guide
jana~/
Head of Department
1
Chapter 1
Introduction
This section introduces to both the methods of firing the projectile. The first discussed method
is the traditional one which was employed earlier in the warfare while the other method is
modern one where fuzzy logic is utilized.
In the early stages the distance at which the target is located was given by one person
called as forward observer. This person who was situated in the nearby area would compute the
distance at which the target is located with the help of binoculars. Once the distance was
determined, he would give this value to the operating staff of the cannon. Depending upon the
distance the cannon would be adjusted and then fired. The movement of the cannon by done
manually by the soldiers in the beginning but today the motors and gears drives the cannon.
This method makes use of something called as firing table during firing. The firing table is
nothing but a database created by taking tests of the cannon. This table accounts for wind
velocity, air temperature and atmospheric pressure correction factors in the trajectory
determination. So each time the forward observer gives distance of the target, using firing table
data the soldiers set the cannon accordingly. This procedure is described with the following
image.
2
Figure 1 Earlier Firing Procedure
The second method which is introduced is the modern firing approach which uses fuzzy logic
knowledge. The need for this method is clear as the earlier method states that the forward
observer gives information to the control center until the projectile hits the exact desired
location. This shows that the method is time consuming and of lesser accuracy.
Modern approach to this process eliminates all the complexity involved. Once the distance
of the target is acquired, the algorithm computes the angle required for corresponding distance
taking into account the factors mentioned above. The software used for angle determination is
based on the fuzzy logic rules. These rules are simple IF-THEN rules which create the
membership functions forming the fuzzy system. Once the system gives computed angle of
firing then electronic circuitry is employed to drive the mechanical assembly which adjusts the
barrel of the cannon. The electronic circuitry is basic signal conditioning circuit which converts
the angle value into suitable electronic signal to drive gear and motor assembly. Results taken
using this method shows that it is easier for computation and takes less time for firing.
3
Chapter 2
Literature Review
Information given in this section is a compilation of all the data that forms the core for this
project. Methodology of the earlier firing method is given in brief. Projectile shell
specifications and its various types depending upon many factor is presented next. As the
projectile interacts in the non-vacuum model, environmental factors must be addressed and so a
realistic model must be analyzed. Various forces that act on the projectile during motion are
explained and suitable assumptions are made. Differential equations are required to compute
and explain the projectile motion in non-vacuum model. Depending upon the accuracy required
and factors to be considered, four major different sets of differential equations are used for
computation. These equations are presented and model which is used for this project i.e. point
mass model in given in detail. In the last part the basic rules and theory of fuzzy logic is
presented with the steps required for constructing fuzzy systems.
2.1 Howitzer introduction:
Information about Howitzer from Wikipedia pages is collected and presented below:
A howitzer is a type of artillery piece characterized by a relatively short barrel and the use of
comparatively small propellant charges to propel projectiles at relatively high trajectories, with
a steep angle of descent. Until fairly recently, about the end of the Second World War, such
weapons were characterized by a barrel length 15 to 25 times the caliber of the gun.
In the taxonomies of artillery pieces used by European (and European-style) armies in the 17th,
18th, 19th, and 20th centuries, the howitzer stood between the "gun" (characterized by a longer
barrel, larger propelling charges, smaller shells, higher velocities, and flatter trajectories) and
the "mortar" (which was meant to fire at even higher angles of ascent and descent). Howitzers,
like other artillery pieces, are usually organized in groups called batteries.
The English word howitzer comes from the Czech word houfnice, from houf, "crowd",
suggesting the cannon's use against massed enemies, and houf is in turn a borrowing from the
4
Middle High German word Hūfe or Houfe (modern German Haufen), meaning "heap". Haufen,
sometimes in the compound Gewalthaufen, also designated a pike square formation in German.
Since the First World War, the word howitzer has been increasingly used to describe artillery
pieces that, strictly speaking, belong to the category of gun-howitzer - relatively long barrels
and high muzzle velocity combined with multiple propelling charges and high maximum
elevation. This is particularly true in the armed forces of the United States, where gun-
howitzers have been officially described as "howitzers" for more than sixty years. Because of
this practice, the word "howitzer" is used in some armies as a generic term for any kind of
artillery piece that is designed to attack targets using indirect fire. Thus, artillery pieces that
bear little resemblance to howitzers of earlier eras are now described as howitzers, although the
British call them guns. Most other armies in the world still reserve the word howitzer for guns
with barrel length 15 to 25 times its caliber, longer-barreled guns being cannons.
The British had a further method of nomenclature that they adopted in the 19th century. Guns
were categorized by projectile weight in pounds while howitzers were categorized by caliber in
inches. This system broke down in the 1930s with the introduction of gun-howitzers.
Current U.S. Military doctrine defines howitzers as any cannon artillery capable of high-angle
(45' to 90' elevation) and low angle (45' to 0' elevation); guns are defined as only capable of
low-angle fire and mortars are only capable of high-angle fire.
In the early 20th century the introduction of howitzers that were significantly larger than the
heavy siege howitzers of the day made necessary the creation of a fourth category, that of
"super-heavy siege howitzers". Weapons of this category include the famous Big Bertha of the
German Army and the 15-inch (381 mm) howitzer of the Royal Marine Artillery. These large
howitzers were transported mechanically rather than by teams of horses. They were transported
as several loads and had to be assembled on their firing position.
Types of Howitzer:
1. A self-propelled howitzer is mounted on a tracked or wheeled motor vehicle. In many cases,
it is protected by some sort of armor so that it superficially resembles a tank, but mostly it's not
designed for front line and cannot withstand direct anti-armor fire, instead protecting crew from
shrapnel and small arms.
2. A pack howitzer is a relatively light howitzer that is designed to be easily broken down into
several pieces, each of which is small enough to be carried by a mule or a packhorse.
5
3. A mountain howitzer is a relatively light howitzer designed for use in mountainous terrain.
Most, but not all, mountain howitzers are also pack howitzers.
4. A siege howitzer is a howitzer that is designed to be fired from a mounting on a fixed
platform of some sort.
5. A field howitzer is a howitzer that is mobile enough to accompany a field army on campaign.
It is invariably provided with a wheeled carriage of some sort.
Figure 2: HOWITZER image
6
2.2 Earlier firing methods:
Forward Observer (FO) is a vital component in the whole firing process. This observer was in
the earlier periods essentially a person which gives distance of the target for firing. Forward
observer is equipped with binoculars for viewing and compass for determining surrounding
wind velocity. These people are trained to carry out these operations efficiently. In modern
periods these observers are being replaced with powerful viewing instruments for increasing
accuracy. The whole unit carrying out these firing operations is known as the Field Artillery
Team.
Figure 3: Role of Forward Observer in firing process
Following article from the Wikipedia website and field army manual gives this information
regarding Forward Observer and Field Artillery Team:
In the land-based field artillery, the field artillery team is organized to direct and control
indirect artillery fire on the battlefield. Since World War I, to conduct indirect artillery fire,
three distinct components have evolved in this organization: the forward observer (or FO), the
fire direction center (FDC) and what is called the gun line (the actual guns themselves). On the
battlefield, the field artillery team consists of some combinations of all of these elements. In
other words there may be multiple FOs calling in fire on multiple targets to multiple FDCs and
7
any component may be in communication with some of the other elements depending on the
situational requirements.
2.2.1 Motivation:
To understand the modern field artillery team concept, it is necessary to understand that
modern artillery batteries shoot at targets measured in distances of kilometers and miles rather
than the old 18th Century concept of meters and yards, representing a hundredfold increase in
range. This dramatic range increase has been driven by the development of rifled cannons,
improvements in propellants, better communications and technical improvements in gunnery
computational abilities that have been ongoing since the end of the 19th Century. Since a
modern enemy is engaged at such great distances, in most cases, gunners no longer directly see
their targets and so they can not directly engage the enemy with observed direct fire, thus there
is a need for trained observers linked to the artillery units by modern communications to find
and adjust fire on targets at great distances. In most field artillery situations, because of
weather, terrain, night-time conditions, distance or other obstacles, the soldiers manning the
guns cannot see the target that they are firing upon. The term indirect fire is therefore used to
describe firing at targets that gunners cannot see. In most cases, the target is either over the
horizon or on the other side of some physical obstruction, such as a hill, mountain or valley.
Since the target is not visible these gunners have to rely on a trained artillery observer, also
called a forward observer, who sees the target and relays the coordinates of the target to their
fire direction center. The fire direction center, in turn, translates those coordinates into first, a
left-right aiming direction, second, an elevation angle, third, a calculated number of bags of
propellant and finally, a fuse with a determined waiting time before exploding to be set (if
necessary). The fuse is then mated to the artillery projectile.
2.2.2 Organization:
2.2.2.1 Forward Observer (FO):
Because artillery is an indirect fire weapon, the forward observer must take up a position where
he can observe the target using tools such as maps, compass, binoculars and laser
rangefinder/designators; then call back fire missions on his radio or other communication
8
device. This position can be anywhere from a few hundred meters to 20–30 km distant from the
guns. Modern day FOs are also trained in the rudiments of calling Close Air Support, Sea-
borne Weapons and other weapons systems.
Using a standardized format, the FO sends either an exact target location or the position relative
to his own location or a registered map point, a brief target description, a recommended
ammunition to use, and any special instructions such as "danger close" (The warning that
friendly troops are within a certain distance from the target, which varies based upon the
weapon system being used and which requires extra precision from the guns). Once firing
begins, if the rounds are not accurate the FO will issue instructions to adjust fire in four
dimensions (Three physical; left/right, forward/back, up/down and one for time, when using
timed fuses) and then usually call "fire for effect", unless his purpose in that fire mission has an
objective other than suppression or destruction of the target. A "Fire For Effect" or "FFE" calls
for all of the guns or tubes to fire a round; as opposed to the adjustment phase wherein only a
single gun is firing.
The FO does not talk to the guns directly - he deals solely with the FDC. The forward observer
can also be airborne and in fact one of the original roles of aircraft in the military was airborne
artillery spotting.
2.2.2.2 FDC (Fire Direction Center):
Typically, there is one FDC for a battery of six guns, in a light division. In a typical heavy
division configuration, there exist two FDC elements capable of operating two four gun
sections, also known as a split battery. The FDC computes firing data, fire direction, for the
guns. The process consists of determining the precise target location based on the observer's
location if needed, then computing range and direction to the target from the guns' location.
This data can be computed manually, using special protractors and slide rules with
precomputed firing data. Corrections can be added for conditions such as a difference between
target and howitzer altitudes, propellant temperature, atmospheric conditions, and even the
curvature and rotation of the Earth. In most cases, some corrections are omitted, sacrificing
accuracy for speed. In recent decades, FDCs have become computerized, allowing for much
faster and more accurate computation of firing data.
9
2.2.2.3 Guns:
The final piece of the puzzle is the "gun line" itself. The FDC will transmit a warning order to
the guns, followed by orders specifying the type of ammunition, fuze setting and propelling
charge, bearing, elevation, and the method of adjustment or orders for fire for effect (FFE).
Elevation (vertical direction) and bearing orders are specified in mils, and any special
instructions, such as to wait for the observer's command to fire relayed through the FDC. The
crews load the howitzers and traverse and elevate the tube to the required point, using either
hand cranks (usually on towed guns) or hydraulics (on self-propelled models).
2.2.2.4 Parent battalion and US Army brigade/USMC regimental FDCs:
FDCs also exist in the next higher parent battalion that "owns" 2-4 artillery batteries. Once
again, an FDC exists at the US Army brigade or USMC regimental level that "owns" the
battalions. These higher level FDCs monitor the fire missions of their subordinate units and
will coordinate the use of multiple batteries or even multiple battalions in what is called a
battalion or brigade/regimental mission. In training and wartime exercises, as many as 72 guns
from 3 battalions may all be coordinated to put "steel on the target" in what is called a
"brigade/regimental time on target" or brigade/regimental TOT for short. The rule is "silence is
consent," meaning that if the lower unit does not hear a "cancel the mission" (don't shoot) or
even a "check firing" (cease firing) order from the higher monitoring unit, then the mission
goes on. Higher level units monitor their subordinate unit's missions both for both active as
well as passive purposes. Higher level units also may get involved to coordinate artillery fire
across fire support coordination boundaries (often parallel lines on maps) where one unit
cannot fire into without permission from higher and/or adjacent units that "own" the territory.
10
2.2.2.5 Direct fire exceptions to usual mission of artillery indirect fire:
Artillery gunners are taught how to use direct fire to engage a target such as mounted or
dismounted troops attacking them. In such a case, however, the artillery crews are able to see
what they are shooting at. With indirect fire, in normal artillery missions, the crews manning
the guns cannot see their target directly, or observers are doing that work for them. There have
been exceptions to this situation, but even when US Marines assaulted Iwo Jima during World
War Two, and gunners could see the impact of their rounds on Mt. Suribachi, the actual
adjustment of their fires was accomplished by forward observers directly supporting and
attached to infantry units, because they were in the position to see not only the enemy but to
prevent friendly fire incidents and to coordinate shelling the Japanese with their infantry unit's
movements.
2.2.3 CAPABILITIES AND LIMITATIONS:
A. The accuracy of calls for fire depends on the actions and capabilities of forward observers
(FOs) and company fire support officers (FSOs) and the accuracy of fire support plans.
B. Error-free self-location and precise target location are ideals for which the forward observer
must strive. First-round FFE on a target of opportunity and immediate and effective
suppression of enemy direct fire systems are musts if the supported maneuver unit is to
accomplish its mission. Moreover, accurate location of planned targets is imperative to
effective execution of a fire support plan. Accurate location of planned targets is possible only
if the enemy is under actual observation by a forward observer or other targeting asset. Fire
support may be indirect fire-but it must be directed!
C. Achievement of these goals is primarily situation-dependent. Accuracy of FA fires also
depends to a great extent on the skill and experience of the observer who calls for fire and the
equipment he uses for self-location and target location.
11
D. The traditional forward observer, equipped with a map, compass, and binoculars, can expect
a mean target location error of about 500 meters. This is not enough for reliable first-round FFE
or target suppression; it is no better than it was in World War II. Lengthy adjustments of fire
are required to move the rounds onto the target. This wastes time and ammunition and gives the
enemy a chance to take cover or leave the area.
E. Attainable accuracy for modern observer teams (FISTs, COLTs, and AFSOs), equipped with
electronic and optical devices such as laser range finders and position-locating systems, is
considerably improved. When properly used by trained and qualified observers, these devices
enable the observer to attain first-round accuracy never before possible; but they have inherent
hazardous characteristics. Lasers are not eye-safe and can inflict severe eye injuries. Thus, their
use in training environments is severely restricted. Even in an actual conflict, care must be
taken to prevent injuring unprotected friendly troops. Eye-safe laser range finders for use in
training areas are currently under development and will be fielded when available.
Figure 4: Field Artillery Team
12
2.3 Projectile and shell types:
Various types of projectile are used depending upon distance to be covered and velocity of the
projectile required. 155mm type of projectile is the most common used in the artillery and
readings for this project are of the same. Detailed information regarding this projectile type is
collected from internet and presented in the tabular form below.
2.3.1 155mm Projectile:
The projectiles of the 155mm Howitzer went by many names; shells, projos, rounds, and joes to
name a few. Just as there were many names, so there were several different types of projectiles
to accomplish the many missions the gun was expected to perform. Add several different fuzes,
and two different powders, and the 155 became a very versatile weapon. The first, and most
utilized projectile, was the M107 High Explosive round (HE). With the super quick, point
detonating fuze(PD), the round was used against personnel, and light armor. With the turn of a
screw, the fuze became delayed, and HE round could dig out bunkers, and other fortified
positions. With a Mechanical Time, or Variable Time fuze, the HE would airburst with
devastating effect to troops in the open or even in trenches and foxholes.
To mark where the explosive rounds would hit, or to indicate to a unit in the field where they
were, the M116(A1) Colored Smoke/High Cloud round was used. The smoke was bright red,
purple, or yellow. The high cloud round was white smoke, but could be used as a marker at
night as it left a stream of sparks going into the target. All of the smoke rounds used
mechanical time fuzes.
The White Phosphorus (WP), M110, was also used as a marker round. It could be fitted with
PD, VT, and MT fuzes. When the situation called for it, white phosphorus became a
devastating weapon against personnel. The thick white smoke could be used as a screen to
mask movement by troops in the field.
Illumination was a very important mission for artillery in Vietnam. To accomplish that, the
155mm howitzer used the M485(A1). Each round was capable of lighting up a 1000 yard
diameter area. The flare was ejected at 700 yards altitude, and would stay lit for at least 90
13
seconds. By keeping two flares in the air at a time, shadows were reduced. At a firing rate of
two rounds a minute, an area could be kept lit all night long.
The ICM (Improved Conventional Weapons), or Firecracker round (M449) was used for
antipersonnel missions. An airburst, base ejecting shell, it dropped sixty bomblets that bounced
up five feet in the air before going off. It proved to be extremely effective against enemy in the
open, or in positions with little, or no overhead protection.
We have included the gas round, M121A1 although it is not clear that the 1/92nd ever fired it in
anger. Delivered as an airburst, or as a point detonating round, it contained Ca, or Cs types of
"tear" gas.
Shell M # Color Stripe/ Color
Lettering
Color
Weight in
Pounds
High
Explosive
M107 Olive Drab None Yellow 97
Gas M121A1 Gray
Three Green, One
Yellow
Green 100
WP M110 Lt. Green One Yellow Red 98
Smoke/HC M116(A1) Lt. Green None Black 86
Illumination M485(A1)* Olive Drab One White White 85
ICM M449 Olive Drab
One Row Yellow
Diamonds
Yellow 95
Table 1: Various types of projectiles
* The M485 was to be fired at a maximum charge 6, while the M485A1 could be fired at
Charge 7.
14
Figure 5: Marking of 155mm HE projectile
The 155mm projectiles are the most widely used artillery round. They offer a wide range of
options on the battlefield. The 155mm howitzers are separate loading ammunition, which has
four separate components: primer, propellant, projectile, and fuze. The four components are
issued separately. Upon preparation for firing, the projectile and propellant are loaded into the
howitzer. Separate loading ammunition propellants are issued as a separate unit of issue in
sealed canisters to protect the propellant. The amount of propellant to be fired with artillery
ammunition is varied by the number of propellant increments. The charge selected is based on
the range to the target and the tactical situation.
Figure 6: 155mm HE projectile components
15
Figure 7: Charges used in 155mm projectile
Its accuracy is measured in centimeters, and its lethality is impressive. Copperhead is a cannon-
launched, 155mm artillery projectile which guides itself to a laser-designated target. The
ammunition is capable of defeating both armor and point targets at ranges of over six
kilometers, and provides the battlefield commander with the unparalleled capability of utilizing
artillery to the same effect as direct fire weapons and close air support. The system was
employed during Operation Desert Storm, during which it met with great success. Copperhead
projectiles were used to destroy observation and border guard posts and forward radar
installations during the first week of artillery attacks.
2.3.2 Shells:
A shell is a payload-carrying projectile which, as opposed to shot, contains an explosive or
other filling, though modern usage sometimes includes[citation needed] large solid projectiles
properly termed shot (AP, APCR, APCNR, APDS, APFSDS and proof shot). Solid shot may
contain a pyrotechnic compound if a tracer or spotting charge is used. Originally it was called a
"bombshell", but "shell" has come to be unambiguous in a military context. "Bombshell" is still
used figuratively to refer to a shockingly unexpected happening or revelation.
All explosive- and incendiary-filled projectiles, particularly for mortars, were originally called
grenades, derived from the pomegranate, whose seeds are similar to grains of powder. Words
16
cognate with grenade are still used for artillery or mortar projectile in some European
languages.
Shells are usually large-calibre projectiles fired by artillery and combat vehicles (including
tanks), and warships. Shells usually have the shape of a cylinder topped by an ogive-shaped
nose for good aerodynamic performance, possibly with a tapering base; but some specialized
types are quite different.
Solid cannonballs (“shot”) did not need a fuse, but hollow munitions (“shells”) filled with
something such as gunpowder to fragment the ball, needed a fuse, either impact (percussion) or
time. Percussion fuses with a spherical projectile presented a challenge because there was no
way of ensuring that the impact mechanism hit the target. Therefore shells needed a time fuse
that was ignited before or during firing and burnt until the shell reached its target. Early reports
of shells include Venetian use at Jadra in 1376 and shells with fuses at the 1421 siege of St
Boniface in Corsica. These were two hollowed hemispheres of stone or bronze held together by
an iron hoop. Written evidence for early explosive shells in China appears in the early Ming
Dynasty (1368–1644) Chinese military manual Huolongjing, compiled by Jiao Yu (fl. 14th to
early 15th century) and Liu Ji (1311–1375) sometime before the latter's death, a preface added
by Jiao in 1412. As described in their book, these hollow, gunpowder-packed shells were made
of cast iron.
Shells have never been limited to an explosive filling. An incendiary shell was invented by
Valturio in 1460. The carcass was invented in 1672 by a gunner serving Christoph van Galen,
Prince Bishop of Munster, initially oblong in an iron frame or carcass (with poor ballistic
properties) it evolved into a spherical shell. Their use continued well into the 19th Century. In
1857 the British introduced an incendiary shell (Martin's) filled with molten iron, which
replaced red hot shot used against ships, most notably at Gibraltar in 1782. Two patterns of
incendiary shell were used by the British in World War 1, one designed for use against
Zeppelins.
The calibre of a shell is its diameter. Depending on the historical period and national
preferences, this may be specified in millimetres, centimetres, or inches. The length of gun
barrels for large cartridges and shells (naval) is frequently quoted in terms of the ratio of the
barrel length to the bore size, also called calibre. For example, the 16"/50 caliber Mark 7 gun is
50 calibers long, that is, 16"×50=800"=66.7 feet long. Some guns, mainly British, were
specified by the weight of their shells. Due to manufacturing difficulties the smallest shells
17
commonly used are around 20 mm calibre, used in aircraft cannon and on armored vehicles.
Smaller shells are only rarely used as they are difficult to manufacture and can only have a
small explosive charge. The largest shells ever fired were those from the German super-railway
guns, Gustav and Dora, which were 800 mm (31.5") in calibre. Very large shells have been
replaced by rockets, guided missile, and bombs and today the largest shells in common use are
155 mm (6.1"). Gun calibres have standardized around a few common sizes, especially in the
larger range, mainly due to the uniformity required for efficient military logistics. Shells of
105, 120, and 155 mm diameter are common for NATO forces' artillery and tank guns.
Artillery shells of 122, 130 and 152 mm, and tank gun ammunition of 100, 115, or 125 mm
calibre remain in use in Eastern Europe and China. Most common calibres have been in use for
many years, since it is logistically complex to change the calibre of all guns and ammunition
stores. The weight of shells increases by and large with calibre. A typical 150 mm (5.9") shell
weighs about 50 kg, a common 203 mm (8") shell about 100 kg, a concrete demolition 203 mm
(8") shell 146 kg, a 280 mm (11") battleship shell about 300 kg, and a 460 mm (18") battleship
shell over 1500 kg. The Schwerer Gustav supergun fired 4.8 and 7.1 tonne shells.
Figure 8: Some sectioned shells from World War 1
2.3.3 Fuzes:
Fuzes form an important component in the projectile. It is used in the explosion of the
projectile. The fuzes were as varied as the projectiles. Depending on which round was used,
and the mission it was to perform, several of the rounds took two or more fuzes. Here are the
fuzes, and what they were used for.
Fuze Type Uses Projectiles
M557/M739 SQPD/Delay Impact/Subsurface HE,WP,Gas
18
M564 MT/SQ Airburst/Impact HE,WP,Gas
M565 MT Airburst Illumination, M449
M501(A1) MT/SQ Airburst/Impact High Cloud/Smoke
M729 Proximity/SQ Airburst/Impact HE, WP, Gas
M78(A1) CP/Delay Concrete HE, WP, Gas
Table 2: Various types of shells and its uses
2.4 Point mass model:
Different types of model are available for computation of projectile motion with the simplest
one being vacuum model and the most complicated one being 6DOF (degree of freedoms)
model. For the sake of simplicity and required accuracy, a Point Mass Model is implemented in
this project. The differential equations regarding this model are presented with suitable
assumptions.
This model assumes that all the projectile mass is located at a single point. This model also
accounts for the drag caused by the air, but like the vacuum model, it neglects the aerodynamic
forces and moments that act on projectile. The trajectory is given by the following set of
equations:
19
Where is the „p‟ air density, „d‟ is the projectile diameter, „Cd‟ is the drag coefficient, „m‟ is the
projectile mass, is the range, „y‟ is the height, „z‟ is the drift, „Wx‟, „Wy‟ and „Wz‟ are wind
velocity for the three axes . This model is fairly accurate and has been used by manufacturers to
generate firing tables for some period of time.
Following is the article extracted from the manual of the BRL. It explains the use of differential
equations assuming point mass model for computing the trajectories of the projectile.
The equations of motion, incorporating all six degrees of freedom of a body in free flight, have
been programmed for the BRLESC and are used for the burning phase of rocket trajectories.
The procedure is a very lengthy one, however; even on the very high speed BRLESC, average
computing time is approximately 4 seconds per second of time of flight. For cannon artillery
tables, this computing time would be prohibitive. In preparing a firing table for a howitzer, we
compute about 200,000 trajectories having an average time of flight of about 50 seconds. This
would mean approximately 10,000 hours of computer time. In contrast, the equations of motion
for the particle theory, which are currently used for computing firing tables for cannon artillery,
use far less computer time: approximately 1 second per 160 seconds of time of flight. For the
same howitzer table used as an example above, approximately 20 hours of computer time are
required.
Although the trajectory computed by the particle theory does not yield an exact match along an
actual trajectory, it does match the end points. For present purposes, this theory provides the
requisite degree of accuracy for artillery firing tables.
The accelerations, velocities and positions necessary to describe the particle theory are
referenced to a ground-fixed, right hand, coordinate system. The equations of motion which are
used in the machine reduction of the fitting data are:
20
Where the dots indicate differentiation with respect to time,
1. x, y and z - distances along the x, y and z axes,
2. p - air density as a function of height,
3. V - velocity,
4. KD - drag coefficient,
5. C - ballistic coefficient,
6. Wx - range wind,
7. Wz - cross wind,
8. g - acceleration due to gravity,
9. ax, ay and az are accelerations due to the rotation of the earth.
For a given projectile, KD varies with Mach number and with angle of attack. The ballistic
coefficient, C, defined as weight over diameter squared (W/d2) is a constant. However, for
convenience in handling data along any given trajectory, KD is allowed to vary only with Mach
number, and C becomes a variable. In other words, the KD used is that for zero angle of attack.
In actual flight, drag increases with an increase in angle of departure, due to large summital
yaws at high angles. Thus, if KD is not allowed to increase with increasing angle, C will
decrease in order to maintain the correct KD /C ratio. Up to an angle of departure of 45 degree,
however, sumnital yaws are so small that C is usually a constant for any given muzzle velocity.
21
2.5 Ballistic coefficient, Drag coefficient and Mach number:
It started back around 1850 when ballisticians of many countries began experiments in an effort
to improve the accuracy of artillery shells and the measurements of the drag or air resistance
they encountered during flight. Basically, the necessities of war meant everyone wanted more
accuracy. There were no computers back in those days so all the mathematical solutions to
these very complex equations were hand written. These took months and even years to
complete. Between 1875 and 1898, German, French, Russian and English ballisticians worked
feverishly to quantify air drag resistance of artillery shells and finally came up with a standard
model of projectile on which further calculations could be based. This made it a little easier to
calculate the trajectories of new shaped projectiles by reducing the time required for new
calculations. This standard reference projectile shape is known as the G1 Standard bullet. "G"
stands for the Gâvre Commission of the French Naval Artillery. This commission conducted
many air resistance firings at the Gâvre Proving Ground utilizing a Belgian chronograph
manufactured in 1864. Figure illustrates the shape and measurement of this projectile in
"calibres". One calibre is the width of the projectile.
Figure 9: Measurement of projectile in calibres
The G1 projectile was one pound in weight (lead), and was one inch in diameter. This hefty
7000 grain (1lb) projectile is basically what most small-arms projectiles today are measured
against for their ballistic coefficient reference numbers.
22
2.5.1 Drag and form factors:
The amount of drag that a projectile experiences in supersonic flight depends heavily on its
shape and velocity. The speed of sound at sea level at a 15°C and 78% relative humidity (RH)
may be around 1116fps (340m/s). This can be referred to as Mach 1. A projectile travelling at
this speed is travelling at the same speed that sound travels in the same atmosphere. A
projectile travelling in this same atmosphere at 2232fps will be doing Mach 2. Mach 2.5 would
be approximately 2790fps and so on.
A projectile travelling at these speeds has shock waves of compressed air attached to the front
and rear, which tend to draw a large amount of energy from it, thus slowing it down
aggressively. These shock waves are attached to the projectile at certain angles that change at
different speeds and, as a result, draw different amounts of energy from the projectile. What
this means is that the amount of drag or resistance on the projectile varies at different speeds.
The two main factors that affect drag (air resistance) on a spin-stabilised free-flight projectile
are shape and velocity. The blunt-nosed G1 projectile will be less efficient through the air than
the G7 as it is simply not as streamlined. The relationship of a projectile's weight and its cross-
sectional area is called the "sectional density".
The "form factor" of a projectile is a numerical figure that compares a projectile's unique drag
to that of a standard or reference bullet such as the G1 or G7 projectile. The lower the form
factor (FF) of the projectile, the more efficient it is. Comparing the G1 to the G7:
At a velocity of 2792fps the amount of drag on the G1 projectile can be quantified into a
numerical figure of, say, 0.540. At the same velocity, the G7 projectile may have a drag
coefficient of 0.270. The lower the drag coefficient (CD), the more efficient it is through the
air. Compare these two by dividing the G7 by the G1 figures and you have the G1 form factor
of 0.5. If the figure is below 1.0 the projectile is more efficient than the reference projectile.
Figure 10: G7 is twice efficient in air compared to G1
23
2.5.2 Ballistic coefficient:
A ballistic coefficient is a numerical figure usually between 0 and 1 that allows you to see
basically how well it penetrates through the air. The closer, more accurate description would be
"a numerical factor that describes the rate of velocity degradation of a particular projectile
when compared with the rate of velocity degradation of a standard projectile". This figure is
determined by two attributes of the projectile: sectional density and form factor.
The sectional density of a 210gn Berger VLD would be as follows:
Divide this number by the G1 form factor (i1), and you have the G1 ballistic coefficient. This
would read as:
If this projectile was travelling at a lower velocity, the G1 ballistic coefficient would change.
At 2000fps the FF may be around .496. This would mean the G1 BC would be:
24
You can see what is happening here. The i1 FF is changing at different speeds because it is
made from the drag coefficient. The drag coefficient is changing as the velocity is changing
(slowing down). The G1 BC given to us by Berger is the average coefficient experienced
throughout the entire supersonic flight of the projectile. In this instance, the average G1 BC of
this Berger 210gn projectile is 0.631. BCs supplied by other manufacturers may not be the
average, but ones tested at short range at one or more velocities.
Finally, following are 3 simple rules to remember:
1. The higher the ballistic coefficient, the better it slices through the air.
2. The higher the drag coefficient, the worse it slices through the air.
3. The higher the sectional density, the deeper the penetration.
25
2.5.3 Mach number:
Mach number is a dimensionless quantity and it is defined as the ratio of velocity of projectile
to the velocity of sound at standard conditions. Mathematically this quantity is represented as:
Where,
1. M is the Mach number,
2. v is the velocity of the projectile in the medium, and
3. vsound is the speed of sound in the medium.
In projectile motion this quantity changes with respect to the drag coefficient of the projectile.
Following table is taken from BRL manual which shows relationship between Mach number
and drag coefficient (KD) for the 155mm projectile „HE M101‟.
Figure 11: Mach number variation with drag coeffient for HE M101
26
2.6 Fuzzy logic basics & fuzzy systems:
Fuzzy logic can be conceptualized as a generalization of classical logic. Modern fuzzy logic
was developed by Lotfi Zadeh in the mid-1960s to model those problems in which imprecise
data must be used or in which the rules of inference are formulated in a very general way
making use of diffuse categories. In fuzzy logic, which is also sometimes called diffuse logic,
there are not just two alternatives but a whole continuum of truth values for logical
propositions. A proposition A can have the truth value 0.4 and its complement Ac
the truth
value 0.5. According to the type of negation operator that is used, the two truth values must not
be necessarily add up to 1.
Fuzzy logic has a weak connection to probability theory. Probabilistic methods that deal with
imprecise knowledge are formulated in the Bayesian framework, but fuzzy logic does not need
to be justified using a probabilistic approach. The common route is to generalize the findings of
multivalued logic in such a way as to preserve part of the algebraic structure. There is a strong
link between set theory, logic, and geometry. A fuzzy set theory corresponds to fuzzy logic and
the semantic of fuzzy operators can be understood using a geometric model. The geometric
visualization of fuzzy logic will give us a hint as to the possible connection with neural
networks.
Fuzzy logic can be used as an interpretation model for the properties of neural networks, as
well as for giving a more precise description of their performance. It can be shown that fuzzy
operators can be conceived as generalized output functions of computing units. Fuzzy logic can
also be used to specify networks directly without having to apply a learning algorithm. An
expert in a certain field can sometimes produce a simple set of control rules for a dynamical
system with less effort than the work involved in training a neural network. A classical example
proposed by Zadeh to the neural network community is developing a system to park a car. It is
straightforward to formulate a set of fuzzy rules for this task, but it is not immediately obvious
how to build a network to do the same nor how to train it. Fuzzy logic is now being used in
many products of industrial and consumer electronics for which a good control system is
sufficient and where the question of optimal control does not necessarily arise.
27
2.6.1 Set concept of fuzzy logic:
The difference between crisp (i.e., classical) and fuzzy sets is established by introducing a
membership function. Consider a finite set X = {x1, x2, . . . , xn} which will be considered the
universal set in what follows. The subset A of X consisting of the single element x1 can be
described by the n-dimensional membership vector Z(A) = (1, 0, 0, . . . , 0), where the
convention has been adopted that a 1 at the i-th position indicates that xi belongs to A. The set
B composed of the elements x1 and xn is described by the vector Z(B) = (1, 0, 0, ..., 1). Any
other crisp subset of X can be represented in the same way by an n-dimensional binary vector.
But what happens if we lift the restriction to binary vectors? In that case we can define the
fuzzy set C with the following vector description:
Z(C) = (0.5, 0, 0, ..., 0)
In classical set theory such a set cannot be defined. An element belongs to a subset or it does
not. In the theory of fuzzy sets we make a generalization and allow descriptions of this type. In
our example the element x1 belongs to the set C only to some extent. The degree of
membership is expressed by a real number in the interval [0, 1], in this case 0.5. This
interpretation of the degree of membership is similar to the meaning we assign to statements
such as “person x1 is an adult”. Obviously, it is not possible to define a definite age which
represents the absolute threshold to enter into adulthood. The act of becoming mature can be
interpreted as a continuous process in which the membership of a person to the set of adults
goes slowly from 0 to 1.
There are many other examples of such diffuse statements. The concepts “old” and “young” or
the adjectives “fast” and “slow” are imprecise but easy to interpret in a given context. In some
applications, such as expert systems, for example, it is necessary to introduce formal methods
capable of dealing with such expressions so that a computer using rigid Boolean logic can still
process them. This is what the theory of fuzzy sets and fuzzy logic tries to accomplish.
28
Figure 12: Membership functions for the concepts young, mature and old
Above figure shows three examples of a membership function in the interval 0 to 70 years. The
three functions define the degree of membership of any given age in the sets of young, adult,
and old ages. If someone is 20 years old, for example, his degree of membership in the set of
young persons is 1.0, in the set of adults 0.35, and in the set of old persons 0.0. If someone is
50 years old the degrees of membership are 0.0, 1.0, 0.3 in the respective sets.
2.6.2 Fuzzy logic rules & fuzzy system:
We can introduce basic operations on fuzzy sets. Similar to the operations on crisp sets we also
want to intersect, unify and negate fuzzy sets. In his very first paper about fuzzy sets [1], L. A.
Zadeh suggested the minimum operator for the intersection and the maximum operator for the
union of two fuzzy sets. It can be shown that these operators coincide with the crisp unification,
and intersection if we only consider the membership degrees 0 and 1. For example, if A is a
fuzzy interval between 5 and 8 and B be a fuzzy number about 4 as shown in the Figure below:
Figure 13: Example fuzzy sets
29
In this case, the fuzzy set between 5 and 8 AND about 4 is:
Figure 14: Example of fuzzy operation AND (min)
Set between 5 and 8 OR about 4 is shown in the next figure:
Figure 15: Example of fuzzy operation OR (max)
The NEGATION of the fuzzy set A is shown below:
Figure 16: Fuzzy operation NEGATION
The above mentioned rules: AND (min), OR (max) and NEGATION form basics for the
IF-THEN rules which are required to construct the fuzzy system.
30
Fuzzy system consists of three components: Fuzzification, Rule evaluation & Defuzzification.
Following images shown below assists in get some idea.
Figure 17: Fuzzy system components
Figure 18: Steps involved in designing Fuzzy system
Above example shows how a fuzzy system can be designed for a simple case where tip to the
waiter of the restaurant is decided depending upon the food quality and service provided
31
Chapter 3
Present Work
The work discussed here mainly focuses on the software algorithm development for the
determination of the firing angle. Block diagram for the project is given which gives idea about
the work flow. In the next part MATLAB programs and MULTISIM circuits are discussed. The
chapter ends with the presentation of the model.
3.1 BLOCK DIAGRAM:
Figure 19: Block diagram depicting work flow
Above block shows all components of the project. Firstly MATLAB program is implemented
which ultimately gives us the angle of firing. This angle is given to angle an analog controller
which will set the howitzer to the required angle. Then it is ready to fire the projectile at desired
target. This projectile is powered by pneumatic energy which is supplied via air compressor.
32
3.2 MATLAB algorithm:
Two main algorithms are developed: Differential equations trajectory computation in
MATLAB SIMULINK modeling & fuzzy logic algorithm. Out of these two algorithms, the
signal which is forwarded to the controllers is from the fuzzy algorithm. One important part to
understand that the fuzzy logic database creation requires data from the differential equations
trajectory algorithm.
3.2.1 Differential equation trajectory algorithm:
The equations earlier discussed in the point mass model system are implemented in this
algorithm. The constant parameters taken are that of 155mm projectile which are obtained from
standard army manuals.
Here is the actual program which is implemented in the MATLAB software. Taking particular
case to demonstrate the steps involved. Following is the statement:
Fire a projectile of 155mm at 3500 meters with a wind velocity of 5 knots. Take the constants
for projectile as defined for standard 155mm one.
1. Script file to determine angle for given range in vacuum.
range=input(' enter the range : ');
theta=(0.5)*asind((range)*(9.81)/(376^2));
range1=[0 range];
theta1=[0 theta];
This program gives basic angle of firing in the vacuum model which neglects air resistance and
wind drift.
33
2. For calculated angle this file computes the trajectory in wind and air drag effect.
%Constants for 155mm shell
c=.152; %Drag Coefficient of a 155mm shell
rho= 1.00649; %kg/m^3 (density of air)
g=9.81; %m/s^2 (acceleration due to gravity)
%Initial Conditions
delta_t= .01; %s
x(1)=0;
y(1)=0;
V=376; %m/s
theta2=max(theta1);
u=V*cosd(theta2);
v=V*sind(theta2);
x=0;
y=0;
t(1)=0; %Start Loop
i=1;
while min(y)> -.001;
ax=-(rho*V*c)/1362.17*(u-.5);
ay=(-(rho*V*c)/1362.17)*v-g;
u=u+ax*delta_t;
v=v+ay*delta_t;
V=sqrt(u^2+v^2);
x(i+1)=x(i)+u*delta_t+.5*ax*delta_t^2;
y(i+1)=y(i)+v*delta_t+.5*ay*delta_t^2;
t(i+1)=t(i)+delta_t; i=i+1;
end
realrange=x(1,i);
realrange1=[0 realrange];
plot(x,y);
xlabel('x distance (m)');
ylabel('y distance (m)');
title('Projectile Path');
This above program gives us the trajectory of the projectile in realistic conditions for the angle
calculated in vacuum model earlier.
34
Figure 20: Trajectory computation in realistic conditions
This trajectory is of angle obtained in vacuum model and its path in the air drag and wind
velocity conditions. Hence, increment of angle is required
3. Final angle of firing computation with the help of SIMULINK model.
35
Figure 21: SIMULINK model to determine angle of firing.
4. Similarly readings of vertical angle at various distances and wind velocity are taken and
compiled into excel sheet.
Figure 22: Compiled readings in excel sheet
36
3.2.2 Fuzzy logic algorithm:
1. Now using this data a fuzzy file is developed in the toolbox called fuzzy logic toolbox in the
MATLAB software. The system developed has 71 IF-THEN rules and it consists of following
2 inputs: distance of the target and wind velocity. The output of the system consists of vertical
firing angle.
Figure 23: Fuzzy toolbox in MATLAB
2. Now output angle is determined by entering input values in the program.
37
Figure 24: Fuzzy rules and output
38
Figure 25: Fuzzy rules and output
3. Next, this fuzzy system is incorporated into the SIMULINK model for convenience.
Figure 26: SIMULINK model for fuzzy system
39
4. 3-D surface displaying relation between parameters depending upon designed rules.
Figure 27: 3D surface of fuzzy system
40
3.3 Hardware implementation for the project:
The angle of firing obtained from the MATLAB algorithm is given to the analog controller
which forms set point for the barrel to position. The electrical circuitry consists of signal
conditioning circuit which performs action on the signal and amplifies suitably to drive servo
motor. This servo motor rotates the gear mechanism which rotates the barrel. Feedback is
provided for accurate positioning of the barrel.
3.3.1 Signal conditioning circuitry:
Below is the actual snapshot of the circuit as well as the simulated model in SIMULINK
software.
Figure 28: Actual signal conditioning circuitry
41
Now two snapshots are shown at two different conditions:
Figure 29: Circuit at max difference between set point & actual
Figure 30: Circuit at zero difference between set point & actual
42
3.3.2 Project model:
Figure 31: Miniature model of HOWITZER
Above image shows model in which the cannon is mounted on the wooden platform and
consists of horizontal motion. The PVC pipe barrel is capable of vertical motion with the help
of servo motor mounted on the stand constructed above plastic platform.
43
Chapter 4
Result and Discussions
Continuing with the particular example taken in the PRESENT WORK section, we compare
following thins for the taken case:
1. Differential equation trajectory algorithm output angle,
2. Fuzzy logic algorithm output angle,
3. Actual angle taken from firing table of army manual
A snapshot of the final trajectory computed with the angle of firing obtained after incrementing
the angle in the SIMULINK MODEL is given below:
Figure 32: Trajectory at required angle of projectile
We can see that the range is 3500 meters as desired. The angle of firing obtained for this
trajectory from SIMULINK model is 9.4 degree.
44
Fuzzy logic output of same case is given below:
Figure 33: Fuzzy rule viewer
We can see that the fuzzy logic algorithm gives output firing angle at 9.5 degree.
45
Finally actual reading from firing table is extracted. Below is the snapshot of firing table for
particular case taken.
Figure 34: Firing table for 155mm projectile
Angle from firing table is 9.7083degree. [For 3500m, +1 head wind factor is +3.5, hence for 5
knot wind it is 3.5*5=17.5 mils. Adding basic elevation of 155 mils, it becomes 17.5
+155=172.5 mils which is 172.5*0.05628=9.7083 degree]
46
Chapter 5
Conclusion and Future scope
Conclusion:
Following results are obtained for particular case of 155mm projectile:
1. Differential equation trajectory algorithm output angle is 9.4 degree,
2. Fuzzy logic algorithm output angle is 9.5 degree,
3. Actual angle taken from firing table of army manual is 9.7 degree.
We may conclude in the end that fuzzy logic can be successfully implemented in the firing
process of HOWITZER. It is lot easier than the formation of firing table which are not only
complicated but also time consuming. Further improvements can be made by designing more
rules in fuzzy system and implementing 6 degree of freedom model for trajectory computation.
Future scope:
1. This model can be interfaced to the MATLAB software via device like PLC making it
completely automatic in operation.
2. Many other parameters can also be included in the system like ground elevation,
velocity of the moving target.
3. Another major future scope includes inclusion of camera on the projectile. The camera
which is mounted on the projectile will capture real time image of the region once the
projectile is fired. Then the location of multiple targets can be determined and upon
giving input parameters to the algorithm designed, the HOWITZER can destroy
multiple targets simultaneously.
47
REFERENCES
1. Baranowski L., 2006, A mathematical model of flight dynamics of field artillery guided
projectiles,6th International Conference on Weaponry “Scientific Aspects of Weaponry”,
Waplewo, 44-53 [in Polish]
2. Baranowski L., 2011, Modeling, Identification and Numerical Study of the Flight
Dynamics of Ballistic Objects for the Need of Field Artillery Fire Control Systems, Military
University of Technology, Warsaw, p. 258 [in Polish]
3. Carlucci, Donald, Sidney Jacobson, (2008) Ballistics: Theory and Design of Guns and
Ammunition, CRC Press, Boca Raton, FL.
4. Lieske, R. F., and Danberg, J. E. (1992) Modified Mass Trajectory Simulation for Base-Burn
Projectiles, ADA248 292, Ballistic Research Laboratories, Aberdeen Proving Ground,
Maryland.
5. Lieske, R. F., and Reiter, M. L. (1966), Equations of Motion for a Modified Point Mass
Trajectory, Report #1314, Ballistic Research Laboratories, Aberdeen Proving Ground,
Maryland.
6. P.M. Gell, Maj. (1987), Textbook of Ballistics and Gunnery, Vol. I, Her Majesty Stationary
Office, London.
Websites:
1. en.wikipedia.org

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BE FINAL YEAR PROJECT (UPDATED)

  • 1. AUTOMATION IN HOWITZER A MAJOR PROJECT REPORT SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF THE DEGREE OF BACHELOR OF ENGINEERING (Instrumentation & Control Engineering) SUBMITTED TO PUNE UNIVERSITY SUBMITTED BY Name of Student University Seat No. Gunjal Gajanan B80784628 Bobhate Rohan B80784649 Kumbhare Prathmesh B80784632 GUIDED BY Professor N.M. Karajanagi HOD – Instrumentation & Control May 2014 (Month & Year of Submission) GOVERNMENT COLLEGE OF ENGINEERING AND RESEARCH AWASARI (KHURD)
  • 2. TABLE OF CONTENTS Page No. Acknowledgement i Abstract ii List of Tables iii List of Figures iv List of Abbreviations v
  • 3. Page No. Chapter 1: INTRODUCTION 1 Chapter 2: LITERATURE REVIEW 3 2.1 Howitzer introduction 3 2.2 Earlier firing methods 6 2.3 Projectile and shell types 12 2.4 Point mass model 18 2.5 Ballistics coefficient, Drag coefficient and Mach number 21 2.6 Fuzzy logic basics and fuzzy systems 26 Chapter 3: PRESENT WORK 3.1 Block diagram 31 3.2 MATLAB algorithm 32 3.3 Hardware implementation for the project 40 Chapter 4: Results And Discussion 43 Chapter 5: Conclusion And Future Scope 46 References 47
  • 4. iii List of Tables Table Title Page 1 Various types of projectile 13 2 Types of shells & its uses 17
  • 5. iv LIST OF FIGURES Figure Title Page 1 HOWITZER image 5 2 Drag coefficient 22 3 Mach number 25 4 Steps in fuzzy system 30 5 Block diagram of model 31 6 Fuzzy Toolbox 36 7 Actual signal conditioning 39 8 Model of HOWITZER 41 9 Firing table of 155mm projectile 44
  • 6. v ABBREVIATION FO Forward observer FDC Fire direction center BRL Ballistics research laboratory
  • 7. ii Abstract Howitzer cannons form a vital part in the war artillery in modern defense of our country. The firing techniques employed in the past were time consuming and a bit tedious. With the introduction of modern technologies this process has been considerably improved with increased accuracy. This project report introduces another novel approach towards the firing technique of Howitzer cannons. This approach demonstrates increased simplicity in designing of firing algorithm and also improvement in the time required for firing. Another important point worth mentioning is this report mainly dwells on the software algorithm developed for the firing process and gives the mechanical part (hardware) secondary importance. The algorithm which has been constructed finds its roots in the fuzzy logic. The firing process becomes relatively easier as the fuzzy logic dictates this algorithm. Computation speed increases and so ultimately the rate of firing improve. Incorporation of software was necessary; the algorithm takes help of MATLAB for fuzzy logic implementation and MULTISIM for electrical circuits. The hardware part (model) is a miniature of Howitzer cannon which is capable of both the movements i.e. the vertical and horizontal rotation. Our model utilizes the pneumatic energy to power the firing projectile. Projectile motion is an active research area and its accuracy is constantly improving but for the sake of simplicity point mass model differential equations and its assumptions were considered. In the latter stages of the report the readings and calculations of the trajectories are included and finally possible future additions are mentioned.
  • 8. ACKNOWLEDGEMENT I would like to place on record my deep sense of gratitude to Prof. N.P. Futane HOD-Dept. of Electronics & Telecommunications Engineering,. Government College Of Engineering And Research, Awasari(Khurd), for his generous guidance, help and useful suggestions. I express my sincere gratitude to Prof N.M. Karajanagi HOD-Dept. ofInstrumentation & Control Engineering, Government College Of Engineering And Research, Awasari(Khurd), for his stimulating guidance, continuous encouragement and supervision throughout the course of present work. I also wish to extend my thanks to Prof. N.P. Wagh and other colleagues for attending my seminars and for their insightful comments and constructive suggestions to improve the quality of this project work. Signature(s) of Students ~n Kumbhare Prathrnesh Gunjal Gajanan (B80784628) (B80784649) (B80784632)
  • 9. CERTIFICATE I hereby certify that the work which is being presented in the B.E. Major Project Report entitled "AUTOMATION IN HOWITZER", in partial fulfillment of the requirements for the award of the Bachelor of Engineering in Instrumentation & Control Engineering and submitted to the Department of Instrumentation & Control Engineering of Government College of Engineering & Research,Awasari (Khurd) is an authentic record of my own work carried out during a period from July 2013 to June 2014 under the supervision of Prof. N.M. Karajanagi, HOD- Instrumentation & Control Department. The matter presented in this Project Report has not been submitted by me for the award of any other degree elsewhere. ~. Gunjal Gajanan (880784628) Signature ofStudent B£:(880784649) Kumbhare Prathmesh (880784632) This is to certify that the above statement made by the student(s) is correct to the best of my knowledge. Signature of External Examiner Signature of Principal Prof. . Project Guide jana~/ Head of Department
  • 10. 1 Chapter 1 Introduction This section introduces to both the methods of firing the projectile. The first discussed method is the traditional one which was employed earlier in the warfare while the other method is modern one where fuzzy logic is utilized. In the early stages the distance at which the target is located was given by one person called as forward observer. This person who was situated in the nearby area would compute the distance at which the target is located with the help of binoculars. Once the distance was determined, he would give this value to the operating staff of the cannon. Depending upon the distance the cannon would be adjusted and then fired. The movement of the cannon by done manually by the soldiers in the beginning but today the motors and gears drives the cannon. This method makes use of something called as firing table during firing. The firing table is nothing but a database created by taking tests of the cannon. This table accounts for wind velocity, air temperature and atmospheric pressure correction factors in the trajectory determination. So each time the forward observer gives distance of the target, using firing table data the soldiers set the cannon accordingly. This procedure is described with the following image.
  • 11. 2 Figure 1 Earlier Firing Procedure The second method which is introduced is the modern firing approach which uses fuzzy logic knowledge. The need for this method is clear as the earlier method states that the forward observer gives information to the control center until the projectile hits the exact desired location. This shows that the method is time consuming and of lesser accuracy. Modern approach to this process eliminates all the complexity involved. Once the distance of the target is acquired, the algorithm computes the angle required for corresponding distance taking into account the factors mentioned above. The software used for angle determination is based on the fuzzy logic rules. These rules are simple IF-THEN rules which create the membership functions forming the fuzzy system. Once the system gives computed angle of firing then electronic circuitry is employed to drive the mechanical assembly which adjusts the barrel of the cannon. The electronic circuitry is basic signal conditioning circuit which converts the angle value into suitable electronic signal to drive gear and motor assembly. Results taken using this method shows that it is easier for computation and takes less time for firing.
  • 12. 3 Chapter 2 Literature Review Information given in this section is a compilation of all the data that forms the core for this project. Methodology of the earlier firing method is given in brief. Projectile shell specifications and its various types depending upon many factor is presented next. As the projectile interacts in the non-vacuum model, environmental factors must be addressed and so a realistic model must be analyzed. Various forces that act on the projectile during motion are explained and suitable assumptions are made. Differential equations are required to compute and explain the projectile motion in non-vacuum model. Depending upon the accuracy required and factors to be considered, four major different sets of differential equations are used for computation. These equations are presented and model which is used for this project i.e. point mass model in given in detail. In the last part the basic rules and theory of fuzzy logic is presented with the steps required for constructing fuzzy systems. 2.1 Howitzer introduction: Information about Howitzer from Wikipedia pages is collected and presented below: A howitzer is a type of artillery piece characterized by a relatively short barrel and the use of comparatively small propellant charges to propel projectiles at relatively high trajectories, with a steep angle of descent. Until fairly recently, about the end of the Second World War, such weapons were characterized by a barrel length 15 to 25 times the caliber of the gun. In the taxonomies of artillery pieces used by European (and European-style) armies in the 17th, 18th, 19th, and 20th centuries, the howitzer stood between the "gun" (characterized by a longer barrel, larger propelling charges, smaller shells, higher velocities, and flatter trajectories) and the "mortar" (which was meant to fire at even higher angles of ascent and descent). Howitzers, like other artillery pieces, are usually organized in groups called batteries. The English word howitzer comes from the Czech word houfnice, from houf, "crowd", suggesting the cannon's use against massed enemies, and houf is in turn a borrowing from the
  • 13. 4 Middle High German word Hūfe or Houfe (modern German Haufen), meaning "heap". Haufen, sometimes in the compound Gewalthaufen, also designated a pike square formation in German. Since the First World War, the word howitzer has been increasingly used to describe artillery pieces that, strictly speaking, belong to the category of gun-howitzer - relatively long barrels and high muzzle velocity combined with multiple propelling charges and high maximum elevation. This is particularly true in the armed forces of the United States, where gun- howitzers have been officially described as "howitzers" for more than sixty years. Because of this practice, the word "howitzer" is used in some armies as a generic term for any kind of artillery piece that is designed to attack targets using indirect fire. Thus, artillery pieces that bear little resemblance to howitzers of earlier eras are now described as howitzers, although the British call them guns. Most other armies in the world still reserve the word howitzer for guns with barrel length 15 to 25 times its caliber, longer-barreled guns being cannons. The British had a further method of nomenclature that they adopted in the 19th century. Guns were categorized by projectile weight in pounds while howitzers were categorized by caliber in inches. This system broke down in the 1930s with the introduction of gun-howitzers. Current U.S. Military doctrine defines howitzers as any cannon artillery capable of high-angle (45' to 90' elevation) and low angle (45' to 0' elevation); guns are defined as only capable of low-angle fire and mortars are only capable of high-angle fire. In the early 20th century the introduction of howitzers that were significantly larger than the heavy siege howitzers of the day made necessary the creation of a fourth category, that of "super-heavy siege howitzers". Weapons of this category include the famous Big Bertha of the German Army and the 15-inch (381 mm) howitzer of the Royal Marine Artillery. These large howitzers were transported mechanically rather than by teams of horses. They were transported as several loads and had to be assembled on their firing position. Types of Howitzer: 1. A self-propelled howitzer is mounted on a tracked or wheeled motor vehicle. In many cases, it is protected by some sort of armor so that it superficially resembles a tank, but mostly it's not designed for front line and cannot withstand direct anti-armor fire, instead protecting crew from shrapnel and small arms. 2. A pack howitzer is a relatively light howitzer that is designed to be easily broken down into several pieces, each of which is small enough to be carried by a mule or a packhorse.
  • 14. 5 3. A mountain howitzer is a relatively light howitzer designed for use in mountainous terrain. Most, but not all, mountain howitzers are also pack howitzers. 4. A siege howitzer is a howitzer that is designed to be fired from a mounting on a fixed platform of some sort. 5. A field howitzer is a howitzer that is mobile enough to accompany a field army on campaign. It is invariably provided with a wheeled carriage of some sort. Figure 2: HOWITZER image
  • 15. 6 2.2 Earlier firing methods: Forward Observer (FO) is a vital component in the whole firing process. This observer was in the earlier periods essentially a person which gives distance of the target for firing. Forward observer is equipped with binoculars for viewing and compass for determining surrounding wind velocity. These people are trained to carry out these operations efficiently. In modern periods these observers are being replaced with powerful viewing instruments for increasing accuracy. The whole unit carrying out these firing operations is known as the Field Artillery Team. Figure 3: Role of Forward Observer in firing process Following article from the Wikipedia website and field army manual gives this information regarding Forward Observer and Field Artillery Team: In the land-based field artillery, the field artillery team is organized to direct and control indirect artillery fire on the battlefield. Since World War I, to conduct indirect artillery fire, three distinct components have evolved in this organization: the forward observer (or FO), the fire direction center (FDC) and what is called the gun line (the actual guns themselves). On the battlefield, the field artillery team consists of some combinations of all of these elements. In other words there may be multiple FOs calling in fire on multiple targets to multiple FDCs and
  • 16. 7 any component may be in communication with some of the other elements depending on the situational requirements. 2.2.1 Motivation: To understand the modern field artillery team concept, it is necessary to understand that modern artillery batteries shoot at targets measured in distances of kilometers and miles rather than the old 18th Century concept of meters and yards, representing a hundredfold increase in range. This dramatic range increase has been driven by the development of rifled cannons, improvements in propellants, better communications and technical improvements in gunnery computational abilities that have been ongoing since the end of the 19th Century. Since a modern enemy is engaged at such great distances, in most cases, gunners no longer directly see their targets and so they can not directly engage the enemy with observed direct fire, thus there is a need for trained observers linked to the artillery units by modern communications to find and adjust fire on targets at great distances. In most field artillery situations, because of weather, terrain, night-time conditions, distance or other obstacles, the soldiers manning the guns cannot see the target that they are firing upon. The term indirect fire is therefore used to describe firing at targets that gunners cannot see. In most cases, the target is either over the horizon or on the other side of some physical obstruction, such as a hill, mountain or valley. Since the target is not visible these gunners have to rely on a trained artillery observer, also called a forward observer, who sees the target and relays the coordinates of the target to their fire direction center. The fire direction center, in turn, translates those coordinates into first, a left-right aiming direction, second, an elevation angle, third, a calculated number of bags of propellant and finally, a fuse with a determined waiting time before exploding to be set (if necessary). The fuse is then mated to the artillery projectile. 2.2.2 Organization: 2.2.2.1 Forward Observer (FO): Because artillery is an indirect fire weapon, the forward observer must take up a position where he can observe the target using tools such as maps, compass, binoculars and laser rangefinder/designators; then call back fire missions on his radio or other communication
  • 17. 8 device. This position can be anywhere from a few hundred meters to 20–30 km distant from the guns. Modern day FOs are also trained in the rudiments of calling Close Air Support, Sea- borne Weapons and other weapons systems. Using a standardized format, the FO sends either an exact target location or the position relative to his own location or a registered map point, a brief target description, a recommended ammunition to use, and any special instructions such as "danger close" (The warning that friendly troops are within a certain distance from the target, which varies based upon the weapon system being used and which requires extra precision from the guns). Once firing begins, if the rounds are not accurate the FO will issue instructions to adjust fire in four dimensions (Three physical; left/right, forward/back, up/down and one for time, when using timed fuses) and then usually call "fire for effect", unless his purpose in that fire mission has an objective other than suppression or destruction of the target. A "Fire For Effect" or "FFE" calls for all of the guns or tubes to fire a round; as opposed to the adjustment phase wherein only a single gun is firing. The FO does not talk to the guns directly - he deals solely with the FDC. The forward observer can also be airborne and in fact one of the original roles of aircraft in the military was airborne artillery spotting. 2.2.2.2 FDC (Fire Direction Center): Typically, there is one FDC for a battery of six guns, in a light division. In a typical heavy division configuration, there exist two FDC elements capable of operating two four gun sections, also known as a split battery. The FDC computes firing data, fire direction, for the guns. The process consists of determining the precise target location based on the observer's location if needed, then computing range and direction to the target from the guns' location. This data can be computed manually, using special protractors and slide rules with precomputed firing data. Corrections can be added for conditions such as a difference between target and howitzer altitudes, propellant temperature, atmospheric conditions, and even the curvature and rotation of the Earth. In most cases, some corrections are omitted, sacrificing accuracy for speed. In recent decades, FDCs have become computerized, allowing for much faster and more accurate computation of firing data.
  • 18. 9 2.2.2.3 Guns: The final piece of the puzzle is the "gun line" itself. The FDC will transmit a warning order to the guns, followed by orders specifying the type of ammunition, fuze setting and propelling charge, bearing, elevation, and the method of adjustment or orders for fire for effect (FFE). Elevation (vertical direction) and bearing orders are specified in mils, and any special instructions, such as to wait for the observer's command to fire relayed through the FDC. The crews load the howitzers and traverse and elevate the tube to the required point, using either hand cranks (usually on towed guns) or hydraulics (on self-propelled models). 2.2.2.4 Parent battalion and US Army brigade/USMC regimental FDCs: FDCs also exist in the next higher parent battalion that "owns" 2-4 artillery batteries. Once again, an FDC exists at the US Army brigade or USMC regimental level that "owns" the battalions. These higher level FDCs monitor the fire missions of their subordinate units and will coordinate the use of multiple batteries or even multiple battalions in what is called a battalion or brigade/regimental mission. In training and wartime exercises, as many as 72 guns from 3 battalions may all be coordinated to put "steel on the target" in what is called a "brigade/regimental time on target" or brigade/regimental TOT for short. The rule is "silence is consent," meaning that if the lower unit does not hear a "cancel the mission" (don't shoot) or even a "check firing" (cease firing) order from the higher monitoring unit, then the mission goes on. Higher level units monitor their subordinate unit's missions both for both active as well as passive purposes. Higher level units also may get involved to coordinate artillery fire across fire support coordination boundaries (often parallel lines on maps) where one unit cannot fire into without permission from higher and/or adjacent units that "own" the territory.
  • 19. 10 2.2.2.5 Direct fire exceptions to usual mission of artillery indirect fire: Artillery gunners are taught how to use direct fire to engage a target such as mounted or dismounted troops attacking them. In such a case, however, the artillery crews are able to see what they are shooting at. With indirect fire, in normal artillery missions, the crews manning the guns cannot see their target directly, or observers are doing that work for them. There have been exceptions to this situation, but even when US Marines assaulted Iwo Jima during World War Two, and gunners could see the impact of their rounds on Mt. Suribachi, the actual adjustment of their fires was accomplished by forward observers directly supporting and attached to infantry units, because they were in the position to see not only the enemy but to prevent friendly fire incidents and to coordinate shelling the Japanese with their infantry unit's movements. 2.2.3 CAPABILITIES AND LIMITATIONS: A. The accuracy of calls for fire depends on the actions and capabilities of forward observers (FOs) and company fire support officers (FSOs) and the accuracy of fire support plans. B. Error-free self-location and precise target location are ideals for which the forward observer must strive. First-round FFE on a target of opportunity and immediate and effective suppression of enemy direct fire systems are musts if the supported maneuver unit is to accomplish its mission. Moreover, accurate location of planned targets is imperative to effective execution of a fire support plan. Accurate location of planned targets is possible only if the enemy is under actual observation by a forward observer or other targeting asset. Fire support may be indirect fire-but it must be directed! C. Achievement of these goals is primarily situation-dependent. Accuracy of FA fires also depends to a great extent on the skill and experience of the observer who calls for fire and the equipment he uses for self-location and target location.
  • 20. 11 D. The traditional forward observer, equipped with a map, compass, and binoculars, can expect a mean target location error of about 500 meters. This is not enough for reliable first-round FFE or target suppression; it is no better than it was in World War II. Lengthy adjustments of fire are required to move the rounds onto the target. This wastes time and ammunition and gives the enemy a chance to take cover or leave the area. E. Attainable accuracy for modern observer teams (FISTs, COLTs, and AFSOs), equipped with electronic and optical devices such as laser range finders and position-locating systems, is considerably improved. When properly used by trained and qualified observers, these devices enable the observer to attain first-round accuracy never before possible; but they have inherent hazardous characteristics. Lasers are not eye-safe and can inflict severe eye injuries. Thus, their use in training environments is severely restricted. Even in an actual conflict, care must be taken to prevent injuring unprotected friendly troops. Eye-safe laser range finders for use in training areas are currently under development and will be fielded when available. Figure 4: Field Artillery Team
  • 21. 12 2.3 Projectile and shell types: Various types of projectile are used depending upon distance to be covered and velocity of the projectile required. 155mm type of projectile is the most common used in the artillery and readings for this project are of the same. Detailed information regarding this projectile type is collected from internet and presented in the tabular form below. 2.3.1 155mm Projectile: The projectiles of the 155mm Howitzer went by many names; shells, projos, rounds, and joes to name a few. Just as there were many names, so there were several different types of projectiles to accomplish the many missions the gun was expected to perform. Add several different fuzes, and two different powders, and the 155 became a very versatile weapon. The first, and most utilized projectile, was the M107 High Explosive round (HE). With the super quick, point detonating fuze(PD), the round was used against personnel, and light armor. With the turn of a screw, the fuze became delayed, and HE round could dig out bunkers, and other fortified positions. With a Mechanical Time, or Variable Time fuze, the HE would airburst with devastating effect to troops in the open or even in trenches and foxholes. To mark where the explosive rounds would hit, or to indicate to a unit in the field where they were, the M116(A1) Colored Smoke/High Cloud round was used. The smoke was bright red, purple, or yellow. The high cloud round was white smoke, but could be used as a marker at night as it left a stream of sparks going into the target. All of the smoke rounds used mechanical time fuzes. The White Phosphorus (WP), M110, was also used as a marker round. It could be fitted with PD, VT, and MT fuzes. When the situation called for it, white phosphorus became a devastating weapon against personnel. The thick white smoke could be used as a screen to mask movement by troops in the field. Illumination was a very important mission for artillery in Vietnam. To accomplish that, the 155mm howitzer used the M485(A1). Each round was capable of lighting up a 1000 yard diameter area. The flare was ejected at 700 yards altitude, and would stay lit for at least 90
  • 22. 13 seconds. By keeping two flares in the air at a time, shadows were reduced. At a firing rate of two rounds a minute, an area could be kept lit all night long. The ICM (Improved Conventional Weapons), or Firecracker round (M449) was used for antipersonnel missions. An airburst, base ejecting shell, it dropped sixty bomblets that bounced up five feet in the air before going off. It proved to be extremely effective against enemy in the open, or in positions with little, or no overhead protection. We have included the gas round, M121A1 although it is not clear that the 1/92nd ever fired it in anger. Delivered as an airburst, or as a point detonating round, it contained Ca, or Cs types of "tear" gas. Shell M # Color Stripe/ Color Lettering Color Weight in Pounds High Explosive M107 Olive Drab None Yellow 97 Gas M121A1 Gray Three Green, One Yellow Green 100 WP M110 Lt. Green One Yellow Red 98 Smoke/HC M116(A1) Lt. Green None Black 86 Illumination M485(A1)* Olive Drab One White White 85 ICM M449 Olive Drab One Row Yellow Diamonds Yellow 95 Table 1: Various types of projectiles * The M485 was to be fired at a maximum charge 6, while the M485A1 could be fired at Charge 7.
  • 23. 14 Figure 5: Marking of 155mm HE projectile The 155mm projectiles are the most widely used artillery round. They offer a wide range of options on the battlefield. The 155mm howitzers are separate loading ammunition, which has four separate components: primer, propellant, projectile, and fuze. The four components are issued separately. Upon preparation for firing, the projectile and propellant are loaded into the howitzer. Separate loading ammunition propellants are issued as a separate unit of issue in sealed canisters to protect the propellant. The amount of propellant to be fired with artillery ammunition is varied by the number of propellant increments. The charge selected is based on the range to the target and the tactical situation. Figure 6: 155mm HE projectile components
  • 24. 15 Figure 7: Charges used in 155mm projectile Its accuracy is measured in centimeters, and its lethality is impressive. Copperhead is a cannon- launched, 155mm artillery projectile which guides itself to a laser-designated target. The ammunition is capable of defeating both armor and point targets at ranges of over six kilometers, and provides the battlefield commander with the unparalleled capability of utilizing artillery to the same effect as direct fire weapons and close air support. The system was employed during Operation Desert Storm, during which it met with great success. Copperhead projectiles were used to destroy observation and border guard posts and forward radar installations during the first week of artillery attacks. 2.3.2 Shells: A shell is a payload-carrying projectile which, as opposed to shot, contains an explosive or other filling, though modern usage sometimes includes[citation needed] large solid projectiles properly termed shot (AP, APCR, APCNR, APDS, APFSDS and proof shot). Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used. Originally it was called a "bombshell", but "shell" has come to be unambiguous in a military context. "Bombshell" is still used figuratively to refer to a shockingly unexpected happening or revelation. All explosive- and incendiary-filled projectiles, particularly for mortars, were originally called grenades, derived from the pomegranate, whose seeds are similar to grains of powder. Words
  • 25. 16 cognate with grenade are still used for artillery or mortar projectile in some European languages. Shells are usually large-calibre projectiles fired by artillery and combat vehicles (including tanks), and warships. Shells usually have the shape of a cylinder topped by an ogive-shaped nose for good aerodynamic performance, possibly with a tapering base; but some specialized types are quite different. Solid cannonballs (“shot”) did not need a fuse, but hollow munitions (“shells”) filled with something such as gunpowder to fragment the ball, needed a fuse, either impact (percussion) or time. Percussion fuses with a spherical projectile presented a challenge because there was no way of ensuring that the impact mechanism hit the target. Therefore shells needed a time fuse that was ignited before or during firing and burnt until the shell reached its target. Early reports of shells include Venetian use at Jadra in 1376 and shells with fuses at the 1421 siege of St Boniface in Corsica. These were two hollowed hemispheres of stone or bronze held together by an iron hoop. Written evidence for early explosive shells in China appears in the early Ming Dynasty (1368–1644) Chinese military manual Huolongjing, compiled by Jiao Yu (fl. 14th to early 15th century) and Liu Ji (1311–1375) sometime before the latter's death, a preface added by Jiao in 1412. As described in their book, these hollow, gunpowder-packed shells were made of cast iron. Shells have never been limited to an explosive filling. An incendiary shell was invented by Valturio in 1460. The carcass was invented in 1672 by a gunner serving Christoph van Galen, Prince Bishop of Munster, initially oblong in an iron frame or carcass (with poor ballistic properties) it evolved into a spherical shell. Their use continued well into the 19th Century. In 1857 the British introduced an incendiary shell (Martin's) filled with molten iron, which replaced red hot shot used against ships, most notably at Gibraltar in 1782. Two patterns of incendiary shell were used by the British in World War 1, one designed for use against Zeppelins. The calibre of a shell is its diameter. Depending on the historical period and national preferences, this may be specified in millimetres, centimetres, or inches. The length of gun barrels for large cartridges and shells (naval) is frequently quoted in terms of the ratio of the barrel length to the bore size, also called calibre. For example, the 16"/50 caliber Mark 7 gun is 50 calibers long, that is, 16"×50=800"=66.7 feet long. Some guns, mainly British, were specified by the weight of their shells. Due to manufacturing difficulties the smallest shells
  • 26. 17 commonly used are around 20 mm calibre, used in aircraft cannon and on armored vehicles. Smaller shells are only rarely used as they are difficult to manufacture and can only have a small explosive charge. The largest shells ever fired were those from the German super-railway guns, Gustav and Dora, which were 800 mm (31.5") in calibre. Very large shells have been replaced by rockets, guided missile, and bombs and today the largest shells in common use are 155 mm (6.1"). Gun calibres have standardized around a few common sizes, especially in the larger range, mainly due to the uniformity required for efficient military logistics. Shells of 105, 120, and 155 mm diameter are common for NATO forces' artillery and tank guns. Artillery shells of 122, 130 and 152 mm, and tank gun ammunition of 100, 115, or 125 mm calibre remain in use in Eastern Europe and China. Most common calibres have been in use for many years, since it is logistically complex to change the calibre of all guns and ammunition stores. The weight of shells increases by and large with calibre. A typical 150 mm (5.9") shell weighs about 50 kg, a common 203 mm (8") shell about 100 kg, a concrete demolition 203 mm (8") shell 146 kg, a 280 mm (11") battleship shell about 300 kg, and a 460 mm (18") battleship shell over 1500 kg. The Schwerer Gustav supergun fired 4.8 and 7.1 tonne shells. Figure 8: Some sectioned shells from World War 1 2.3.3 Fuzes: Fuzes form an important component in the projectile. It is used in the explosion of the projectile. The fuzes were as varied as the projectiles. Depending on which round was used, and the mission it was to perform, several of the rounds took two or more fuzes. Here are the fuzes, and what they were used for. Fuze Type Uses Projectiles M557/M739 SQPD/Delay Impact/Subsurface HE,WP,Gas
  • 27. 18 M564 MT/SQ Airburst/Impact HE,WP,Gas M565 MT Airburst Illumination, M449 M501(A1) MT/SQ Airburst/Impact High Cloud/Smoke M729 Proximity/SQ Airburst/Impact HE, WP, Gas M78(A1) CP/Delay Concrete HE, WP, Gas Table 2: Various types of shells and its uses 2.4 Point mass model: Different types of model are available for computation of projectile motion with the simplest one being vacuum model and the most complicated one being 6DOF (degree of freedoms) model. For the sake of simplicity and required accuracy, a Point Mass Model is implemented in this project. The differential equations regarding this model are presented with suitable assumptions. This model assumes that all the projectile mass is located at a single point. This model also accounts for the drag caused by the air, but like the vacuum model, it neglects the aerodynamic forces and moments that act on projectile. The trajectory is given by the following set of equations:
  • 28. 19 Where is the „p‟ air density, „d‟ is the projectile diameter, „Cd‟ is the drag coefficient, „m‟ is the projectile mass, is the range, „y‟ is the height, „z‟ is the drift, „Wx‟, „Wy‟ and „Wz‟ are wind velocity for the three axes . This model is fairly accurate and has been used by manufacturers to generate firing tables for some period of time. Following is the article extracted from the manual of the BRL. It explains the use of differential equations assuming point mass model for computing the trajectories of the projectile. The equations of motion, incorporating all six degrees of freedom of a body in free flight, have been programmed for the BRLESC and are used for the burning phase of rocket trajectories. The procedure is a very lengthy one, however; even on the very high speed BRLESC, average computing time is approximately 4 seconds per second of time of flight. For cannon artillery tables, this computing time would be prohibitive. In preparing a firing table for a howitzer, we compute about 200,000 trajectories having an average time of flight of about 50 seconds. This would mean approximately 10,000 hours of computer time. In contrast, the equations of motion for the particle theory, which are currently used for computing firing tables for cannon artillery, use far less computer time: approximately 1 second per 160 seconds of time of flight. For the same howitzer table used as an example above, approximately 20 hours of computer time are required. Although the trajectory computed by the particle theory does not yield an exact match along an actual trajectory, it does match the end points. For present purposes, this theory provides the requisite degree of accuracy for artillery firing tables. The accelerations, velocities and positions necessary to describe the particle theory are referenced to a ground-fixed, right hand, coordinate system. The equations of motion which are used in the machine reduction of the fitting data are:
  • 29. 20 Where the dots indicate differentiation with respect to time, 1. x, y and z - distances along the x, y and z axes, 2. p - air density as a function of height, 3. V - velocity, 4. KD - drag coefficient, 5. C - ballistic coefficient, 6. Wx - range wind, 7. Wz - cross wind, 8. g - acceleration due to gravity, 9. ax, ay and az are accelerations due to the rotation of the earth. For a given projectile, KD varies with Mach number and with angle of attack. The ballistic coefficient, C, defined as weight over diameter squared (W/d2) is a constant. However, for convenience in handling data along any given trajectory, KD is allowed to vary only with Mach number, and C becomes a variable. In other words, the KD used is that for zero angle of attack. In actual flight, drag increases with an increase in angle of departure, due to large summital yaws at high angles. Thus, if KD is not allowed to increase with increasing angle, C will decrease in order to maintain the correct KD /C ratio. Up to an angle of departure of 45 degree, however, sumnital yaws are so small that C is usually a constant for any given muzzle velocity.
  • 30. 21 2.5 Ballistic coefficient, Drag coefficient and Mach number: It started back around 1850 when ballisticians of many countries began experiments in an effort to improve the accuracy of artillery shells and the measurements of the drag or air resistance they encountered during flight. Basically, the necessities of war meant everyone wanted more accuracy. There were no computers back in those days so all the mathematical solutions to these very complex equations were hand written. These took months and even years to complete. Between 1875 and 1898, German, French, Russian and English ballisticians worked feverishly to quantify air drag resistance of artillery shells and finally came up with a standard model of projectile on which further calculations could be based. This made it a little easier to calculate the trajectories of new shaped projectiles by reducing the time required for new calculations. This standard reference projectile shape is known as the G1 Standard bullet. "G" stands for the Gâvre Commission of the French Naval Artillery. This commission conducted many air resistance firings at the Gâvre Proving Ground utilizing a Belgian chronograph manufactured in 1864. Figure illustrates the shape and measurement of this projectile in "calibres". One calibre is the width of the projectile. Figure 9: Measurement of projectile in calibres The G1 projectile was one pound in weight (lead), and was one inch in diameter. This hefty 7000 grain (1lb) projectile is basically what most small-arms projectiles today are measured against for their ballistic coefficient reference numbers.
  • 31. 22 2.5.1 Drag and form factors: The amount of drag that a projectile experiences in supersonic flight depends heavily on its shape and velocity. The speed of sound at sea level at a 15°C and 78% relative humidity (RH) may be around 1116fps (340m/s). This can be referred to as Mach 1. A projectile travelling at this speed is travelling at the same speed that sound travels in the same atmosphere. A projectile travelling in this same atmosphere at 2232fps will be doing Mach 2. Mach 2.5 would be approximately 2790fps and so on. A projectile travelling at these speeds has shock waves of compressed air attached to the front and rear, which tend to draw a large amount of energy from it, thus slowing it down aggressively. These shock waves are attached to the projectile at certain angles that change at different speeds and, as a result, draw different amounts of energy from the projectile. What this means is that the amount of drag or resistance on the projectile varies at different speeds. The two main factors that affect drag (air resistance) on a spin-stabilised free-flight projectile are shape and velocity. The blunt-nosed G1 projectile will be less efficient through the air than the G7 as it is simply not as streamlined. The relationship of a projectile's weight and its cross- sectional area is called the "sectional density". The "form factor" of a projectile is a numerical figure that compares a projectile's unique drag to that of a standard or reference bullet such as the G1 or G7 projectile. The lower the form factor (FF) of the projectile, the more efficient it is. Comparing the G1 to the G7: At a velocity of 2792fps the amount of drag on the G1 projectile can be quantified into a numerical figure of, say, 0.540. At the same velocity, the G7 projectile may have a drag coefficient of 0.270. The lower the drag coefficient (CD), the more efficient it is through the air. Compare these two by dividing the G7 by the G1 figures and you have the G1 form factor of 0.5. If the figure is below 1.0 the projectile is more efficient than the reference projectile. Figure 10: G7 is twice efficient in air compared to G1
  • 32. 23 2.5.2 Ballistic coefficient: A ballistic coefficient is a numerical figure usually between 0 and 1 that allows you to see basically how well it penetrates through the air. The closer, more accurate description would be "a numerical factor that describes the rate of velocity degradation of a particular projectile when compared with the rate of velocity degradation of a standard projectile". This figure is determined by two attributes of the projectile: sectional density and form factor. The sectional density of a 210gn Berger VLD would be as follows: Divide this number by the G1 form factor (i1), and you have the G1 ballistic coefficient. This would read as: If this projectile was travelling at a lower velocity, the G1 ballistic coefficient would change. At 2000fps the FF may be around .496. This would mean the G1 BC would be:
  • 33. 24 You can see what is happening here. The i1 FF is changing at different speeds because it is made from the drag coefficient. The drag coefficient is changing as the velocity is changing (slowing down). The G1 BC given to us by Berger is the average coefficient experienced throughout the entire supersonic flight of the projectile. In this instance, the average G1 BC of this Berger 210gn projectile is 0.631. BCs supplied by other manufacturers may not be the average, but ones tested at short range at one or more velocities. Finally, following are 3 simple rules to remember: 1. The higher the ballistic coefficient, the better it slices through the air. 2. The higher the drag coefficient, the worse it slices through the air. 3. The higher the sectional density, the deeper the penetration.
  • 34. 25 2.5.3 Mach number: Mach number is a dimensionless quantity and it is defined as the ratio of velocity of projectile to the velocity of sound at standard conditions. Mathematically this quantity is represented as: Where, 1. M is the Mach number, 2. v is the velocity of the projectile in the medium, and 3. vsound is the speed of sound in the medium. In projectile motion this quantity changes with respect to the drag coefficient of the projectile. Following table is taken from BRL manual which shows relationship between Mach number and drag coefficient (KD) for the 155mm projectile „HE M101‟. Figure 11: Mach number variation with drag coeffient for HE M101
  • 35. 26 2.6 Fuzzy logic basics & fuzzy systems: Fuzzy logic can be conceptualized as a generalization of classical logic. Modern fuzzy logic was developed by Lotfi Zadeh in the mid-1960s to model those problems in which imprecise data must be used or in which the rules of inference are formulated in a very general way making use of diffuse categories. In fuzzy logic, which is also sometimes called diffuse logic, there are not just two alternatives but a whole continuum of truth values for logical propositions. A proposition A can have the truth value 0.4 and its complement Ac the truth value 0.5. According to the type of negation operator that is used, the two truth values must not be necessarily add up to 1. Fuzzy logic has a weak connection to probability theory. Probabilistic methods that deal with imprecise knowledge are formulated in the Bayesian framework, but fuzzy logic does not need to be justified using a probabilistic approach. The common route is to generalize the findings of multivalued logic in such a way as to preserve part of the algebraic structure. There is a strong link between set theory, logic, and geometry. A fuzzy set theory corresponds to fuzzy logic and the semantic of fuzzy operators can be understood using a geometric model. The geometric visualization of fuzzy logic will give us a hint as to the possible connection with neural networks. Fuzzy logic can be used as an interpretation model for the properties of neural networks, as well as for giving a more precise description of their performance. It can be shown that fuzzy operators can be conceived as generalized output functions of computing units. Fuzzy logic can also be used to specify networks directly without having to apply a learning algorithm. An expert in a certain field can sometimes produce a simple set of control rules for a dynamical system with less effort than the work involved in training a neural network. A classical example proposed by Zadeh to the neural network community is developing a system to park a car. It is straightforward to formulate a set of fuzzy rules for this task, but it is not immediately obvious how to build a network to do the same nor how to train it. Fuzzy logic is now being used in many products of industrial and consumer electronics for which a good control system is sufficient and where the question of optimal control does not necessarily arise.
  • 36. 27 2.6.1 Set concept of fuzzy logic: The difference between crisp (i.e., classical) and fuzzy sets is established by introducing a membership function. Consider a finite set X = {x1, x2, . . . , xn} which will be considered the universal set in what follows. The subset A of X consisting of the single element x1 can be described by the n-dimensional membership vector Z(A) = (1, 0, 0, . . . , 0), where the convention has been adopted that a 1 at the i-th position indicates that xi belongs to A. The set B composed of the elements x1 and xn is described by the vector Z(B) = (1, 0, 0, ..., 1). Any other crisp subset of X can be represented in the same way by an n-dimensional binary vector. But what happens if we lift the restriction to binary vectors? In that case we can define the fuzzy set C with the following vector description: Z(C) = (0.5, 0, 0, ..., 0) In classical set theory such a set cannot be defined. An element belongs to a subset or it does not. In the theory of fuzzy sets we make a generalization and allow descriptions of this type. In our example the element x1 belongs to the set C only to some extent. The degree of membership is expressed by a real number in the interval [0, 1], in this case 0.5. This interpretation of the degree of membership is similar to the meaning we assign to statements such as “person x1 is an adult”. Obviously, it is not possible to define a definite age which represents the absolute threshold to enter into adulthood. The act of becoming mature can be interpreted as a continuous process in which the membership of a person to the set of adults goes slowly from 0 to 1. There are many other examples of such diffuse statements. The concepts “old” and “young” or the adjectives “fast” and “slow” are imprecise but easy to interpret in a given context. In some applications, such as expert systems, for example, it is necessary to introduce formal methods capable of dealing with such expressions so that a computer using rigid Boolean logic can still process them. This is what the theory of fuzzy sets and fuzzy logic tries to accomplish.
  • 37. 28 Figure 12: Membership functions for the concepts young, mature and old Above figure shows three examples of a membership function in the interval 0 to 70 years. The three functions define the degree of membership of any given age in the sets of young, adult, and old ages. If someone is 20 years old, for example, his degree of membership in the set of young persons is 1.0, in the set of adults 0.35, and in the set of old persons 0.0. If someone is 50 years old the degrees of membership are 0.0, 1.0, 0.3 in the respective sets. 2.6.2 Fuzzy logic rules & fuzzy system: We can introduce basic operations on fuzzy sets. Similar to the operations on crisp sets we also want to intersect, unify and negate fuzzy sets. In his very first paper about fuzzy sets [1], L. A. Zadeh suggested the minimum operator for the intersection and the maximum operator for the union of two fuzzy sets. It can be shown that these operators coincide with the crisp unification, and intersection if we only consider the membership degrees 0 and 1. For example, if A is a fuzzy interval between 5 and 8 and B be a fuzzy number about 4 as shown in the Figure below: Figure 13: Example fuzzy sets
  • 38. 29 In this case, the fuzzy set between 5 and 8 AND about 4 is: Figure 14: Example of fuzzy operation AND (min) Set between 5 and 8 OR about 4 is shown in the next figure: Figure 15: Example of fuzzy operation OR (max) The NEGATION of the fuzzy set A is shown below: Figure 16: Fuzzy operation NEGATION The above mentioned rules: AND (min), OR (max) and NEGATION form basics for the IF-THEN rules which are required to construct the fuzzy system.
  • 39. 30 Fuzzy system consists of three components: Fuzzification, Rule evaluation & Defuzzification. Following images shown below assists in get some idea. Figure 17: Fuzzy system components Figure 18: Steps involved in designing Fuzzy system Above example shows how a fuzzy system can be designed for a simple case where tip to the waiter of the restaurant is decided depending upon the food quality and service provided
  • 40. 31 Chapter 3 Present Work The work discussed here mainly focuses on the software algorithm development for the determination of the firing angle. Block diagram for the project is given which gives idea about the work flow. In the next part MATLAB programs and MULTISIM circuits are discussed. The chapter ends with the presentation of the model. 3.1 BLOCK DIAGRAM: Figure 19: Block diagram depicting work flow Above block shows all components of the project. Firstly MATLAB program is implemented which ultimately gives us the angle of firing. This angle is given to angle an analog controller which will set the howitzer to the required angle. Then it is ready to fire the projectile at desired target. This projectile is powered by pneumatic energy which is supplied via air compressor.
  • 41. 32 3.2 MATLAB algorithm: Two main algorithms are developed: Differential equations trajectory computation in MATLAB SIMULINK modeling & fuzzy logic algorithm. Out of these two algorithms, the signal which is forwarded to the controllers is from the fuzzy algorithm. One important part to understand that the fuzzy logic database creation requires data from the differential equations trajectory algorithm. 3.2.1 Differential equation trajectory algorithm: The equations earlier discussed in the point mass model system are implemented in this algorithm. The constant parameters taken are that of 155mm projectile which are obtained from standard army manuals. Here is the actual program which is implemented in the MATLAB software. Taking particular case to demonstrate the steps involved. Following is the statement: Fire a projectile of 155mm at 3500 meters with a wind velocity of 5 knots. Take the constants for projectile as defined for standard 155mm one. 1. Script file to determine angle for given range in vacuum. range=input(' enter the range : '); theta=(0.5)*asind((range)*(9.81)/(376^2)); range1=[0 range]; theta1=[0 theta]; This program gives basic angle of firing in the vacuum model which neglects air resistance and wind drift.
  • 42. 33 2. For calculated angle this file computes the trajectory in wind and air drag effect. %Constants for 155mm shell c=.152; %Drag Coefficient of a 155mm shell rho= 1.00649; %kg/m^3 (density of air) g=9.81; %m/s^2 (acceleration due to gravity) %Initial Conditions delta_t= .01; %s x(1)=0; y(1)=0; V=376; %m/s theta2=max(theta1); u=V*cosd(theta2); v=V*sind(theta2); x=0; y=0; t(1)=0; %Start Loop i=1; while min(y)> -.001; ax=-(rho*V*c)/1362.17*(u-.5); ay=(-(rho*V*c)/1362.17)*v-g; u=u+ax*delta_t; v=v+ay*delta_t; V=sqrt(u^2+v^2); x(i+1)=x(i)+u*delta_t+.5*ax*delta_t^2; y(i+1)=y(i)+v*delta_t+.5*ay*delta_t^2; t(i+1)=t(i)+delta_t; i=i+1; end realrange=x(1,i); realrange1=[0 realrange]; plot(x,y); xlabel('x distance (m)'); ylabel('y distance (m)'); title('Projectile Path'); This above program gives us the trajectory of the projectile in realistic conditions for the angle calculated in vacuum model earlier.
  • 43. 34 Figure 20: Trajectory computation in realistic conditions This trajectory is of angle obtained in vacuum model and its path in the air drag and wind velocity conditions. Hence, increment of angle is required 3. Final angle of firing computation with the help of SIMULINK model.
  • 44. 35 Figure 21: SIMULINK model to determine angle of firing. 4. Similarly readings of vertical angle at various distances and wind velocity are taken and compiled into excel sheet. Figure 22: Compiled readings in excel sheet
  • 45. 36 3.2.2 Fuzzy logic algorithm: 1. Now using this data a fuzzy file is developed in the toolbox called fuzzy logic toolbox in the MATLAB software. The system developed has 71 IF-THEN rules and it consists of following 2 inputs: distance of the target and wind velocity. The output of the system consists of vertical firing angle. Figure 23: Fuzzy toolbox in MATLAB 2. Now output angle is determined by entering input values in the program.
  • 46. 37 Figure 24: Fuzzy rules and output
  • 47. 38 Figure 25: Fuzzy rules and output 3. Next, this fuzzy system is incorporated into the SIMULINK model for convenience. Figure 26: SIMULINK model for fuzzy system
  • 48. 39 4. 3-D surface displaying relation between parameters depending upon designed rules. Figure 27: 3D surface of fuzzy system
  • 49. 40 3.3 Hardware implementation for the project: The angle of firing obtained from the MATLAB algorithm is given to the analog controller which forms set point for the barrel to position. The electrical circuitry consists of signal conditioning circuit which performs action on the signal and amplifies suitably to drive servo motor. This servo motor rotates the gear mechanism which rotates the barrel. Feedback is provided for accurate positioning of the barrel. 3.3.1 Signal conditioning circuitry: Below is the actual snapshot of the circuit as well as the simulated model in SIMULINK software. Figure 28: Actual signal conditioning circuitry
  • 50. 41 Now two snapshots are shown at two different conditions: Figure 29: Circuit at max difference between set point & actual Figure 30: Circuit at zero difference between set point & actual
  • 51. 42 3.3.2 Project model: Figure 31: Miniature model of HOWITZER Above image shows model in which the cannon is mounted on the wooden platform and consists of horizontal motion. The PVC pipe barrel is capable of vertical motion with the help of servo motor mounted on the stand constructed above plastic platform.
  • 52. 43 Chapter 4 Result and Discussions Continuing with the particular example taken in the PRESENT WORK section, we compare following thins for the taken case: 1. Differential equation trajectory algorithm output angle, 2. Fuzzy logic algorithm output angle, 3. Actual angle taken from firing table of army manual A snapshot of the final trajectory computed with the angle of firing obtained after incrementing the angle in the SIMULINK MODEL is given below: Figure 32: Trajectory at required angle of projectile We can see that the range is 3500 meters as desired. The angle of firing obtained for this trajectory from SIMULINK model is 9.4 degree.
  • 53. 44 Fuzzy logic output of same case is given below: Figure 33: Fuzzy rule viewer We can see that the fuzzy logic algorithm gives output firing angle at 9.5 degree.
  • 54. 45 Finally actual reading from firing table is extracted. Below is the snapshot of firing table for particular case taken. Figure 34: Firing table for 155mm projectile Angle from firing table is 9.7083degree. [For 3500m, +1 head wind factor is +3.5, hence for 5 knot wind it is 3.5*5=17.5 mils. Adding basic elevation of 155 mils, it becomes 17.5 +155=172.5 mils which is 172.5*0.05628=9.7083 degree]
  • 55. 46 Chapter 5 Conclusion and Future scope Conclusion: Following results are obtained for particular case of 155mm projectile: 1. Differential equation trajectory algorithm output angle is 9.4 degree, 2. Fuzzy logic algorithm output angle is 9.5 degree, 3. Actual angle taken from firing table of army manual is 9.7 degree. We may conclude in the end that fuzzy logic can be successfully implemented in the firing process of HOWITZER. It is lot easier than the formation of firing table which are not only complicated but also time consuming. Further improvements can be made by designing more rules in fuzzy system and implementing 6 degree of freedom model for trajectory computation. Future scope: 1. This model can be interfaced to the MATLAB software via device like PLC making it completely automatic in operation. 2. Many other parameters can also be included in the system like ground elevation, velocity of the moving target. 3. Another major future scope includes inclusion of camera on the projectile. The camera which is mounted on the projectile will capture real time image of the region once the projectile is fired. Then the location of multiple targets can be determined and upon giving input parameters to the algorithm designed, the HOWITZER can destroy multiple targets simultaneously.
  • 56. 47 REFERENCES 1. Baranowski L., 2006, A mathematical model of flight dynamics of field artillery guided projectiles,6th International Conference on Weaponry “Scientific Aspects of Weaponry”, Waplewo, 44-53 [in Polish] 2. Baranowski L., 2011, Modeling, Identification and Numerical Study of the Flight Dynamics of Ballistic Objects for the Need of Field Artillery Fire Control Systems, Military University of Technology, Warsaw, p. 258 [in Polish] 3. Carlucci, Donald, Sidney Jacobson, (2008) Ballistics: Theory and Design of Guns and Ammunition, CRC Press, Boca Raton, FL. 4. Lieske, R. F., and Danberg, J. E. (1992) Modified Mass Trajectory Simulation for Base-Burn Projectiles, ADA248 292, Ballistic Research Laboratories, Aberdeen Proving Ground, Maryland. 5. Lieske, R. F., and Reiter, M. L. (1966), Equations of Motion for a Modified Point Mass Trajectory, Report #1314, Ballistic Research Laboratories, Aberdeen Proving Ground, Maryland. 6. P.M. Gell, Maj. (1987), Textbook of Ballistics and Gunnery, Vol. I, Her Majesty Stationary Office, London. Websites: 1. en.wikipedia.org