railway crack detector robot report doc

8/19/2019 Railway Crack Detector Robot Report Doc

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RAILWAY TRACK

CRACK DETECTOR

Robot

SYNOPSIS



CHAPTER – 1

INTRODUCTION

There are many reasons why rail tracks crack. In bygone days,

it was common for a rail crack to start near the joint between discrete

rail segments. #anufacturing defects in rail can cause fissures.

"heel burns can also contribute to rail cracks by changing the

metallurgy of a rail. Rails are also more likely to crack when the

weather is cold, when the ballast and ties$sleepers aren%t providing as

much support as they should, and when ground or drainage condition

is such that %pumping% occurs under heavy load. All of these

conditions can contribute to a broken rail, and in turn a possible

derailment.

MANUFACTURING DEFECTS IN RAIL:

The quality of rail steel has improved dramatically since the

early days of railroading. The trend toward using continuously welded

rail &'"R( requires a higher quality rail, due to the cyclic thermal

epansion and contraction stresses that a '"R would be required to

endure. In addition, rail operations in general have been trending

toward higher speed and higher ale)load operation. *nder these

operating conditions, rail pieces rolled in the +th century would likely



break at an unacceptable rate. -espite the improved rail quality and

rail metallurgy, if impurities find their way into rail steel and are not

detected by the quality assurance process, they can cause rail breaks

under certain conditions.

Recent rail)making processes have also been trending toward a

harder rail, requiring less frequent replacements under heavy loads.

This has the side)effect of making the rail more brittle, and thus more

susceptible to brittle fracture rather than plastic deformation. It is

therefore imperative that unintentional impurities in rail be minimied.

WHEEL BURN-RELATED RAIL CRACKS:

"hen a locomotive wheel spins without moving the train

forward &also known as slipping(, the small section of rail directly

under the wheel is heated by the forces of friction between the wheel

and itself. The wheel rests on an area of rail no larger than a dime in

sie, so the heating effect is very localied and occurs very quickly.

"hile wheel burn typically does not cause the entire rail section to

melt, it does heat the steel to red)hot temperatures. As the locomotive

stops slipping and starts moving))or worse still, slips forward by a

matter of inches and heats a different piece of rail))the heated spot



cools down very quickly to normal temperature, especially when the

weather is cold.

This heat)quench process results in annealing of the rail steel

and causes substantial changes to its physical property. It can also

cause internal stresses to form within the steel structure. As the rail

surface cools, it may also become oidied, or undergo other

chemical changes by reacting with impurities that are on the surface

of the rail. The net result of this process is that an area of the rail that

is more susceptible to crackage is created.

WHEEL FLAT-RELATED RAIL CRACKS:

If the brakes are dragging or the ale ceases to move on a rail

vehicle while the train is in motion, the wheel will be dragged along

the head of the rail, causing a %flat spot% to develop on the wheel

surface where it contacts the rail. "hen the brakes are subsequently

released, the wheel will continue to roll around with the flat spot,

causing a banging noise with each rotation. This condition is known

as wheel out of round.

The banging of flat wheels on the rail causes a hammering

action that produces higher dynamic forces than a simple passage of



a round wheel. These dynamic forces can eacerbate a weak rail

condition and cause a rail crack.



'/A0T!R)1

LITERATURE REVIEW

LITERATURE SURVEY

Railway track:

Track)caused derailments are often caused by wide gauge. 0roper

gauge, the distance between rails, is 23.2 inches &four feet, eight)

and)a)half inches( on standard gauge track. As tracks wear from train

traffic, the rails can develop a wear pattern that is somewhat uneven.

*neven wear in the tracks can result in periodic oscillations in the

truck, called %truck hunting.' Truck hunting can be a contributing

cause of derailments.

A rail breaks cleanly, it is relatively easy to detect. A track

occupancy light will light up in the signal tower indicating that a track

circuit has been interrupted. If there is no train in the section, the

signaler must investigate. 4ne possible reason is a clean rail break.

5or detecting the rail break this way, one has to use signal bonds that

are welded or pin braed on the head of the rail. If one uses signal



bonds that are on the web of the rail, one will have a continued track

circuit.

If a rail is merely cracked or has an internal fissure, the track

circuit will not detect it, because a partially)broken rail will continue to

conduct electricity. 0artial breaks are particularly dangerous because

they create the worst kind of weak point in the rail. The rail may then

easily break under load))while a train is passing over it))at the point of

prior fissure.

ULTIMATE AIM

The aim of this project is to find out the cracks developed on

the railway tracks, due to continuous use or while manufacturing. This

is achieved by installing IR &Infra red( sensor and solar power to the

maintenance crew6s wagon.



CHAPTER-3

DESCRIPTION OF EQUIPMENT

3. BATTERY:

7attery is use for storing the energy produced from the solar

power. The battery used is a lead)acid type and has a capacity of

+1v8 1.2A.the most inepensive secondary cell is the lead acid cell

and is widely used for commercial purposes. A lead acid cell when

ready for use contains two plates immersed in a dilute sulphuric acid

&/194:( of specific gravity about +.1;.the positive plate &anode( is of

<ead =peroide &0b41( which has chocolate brown colour and the

negative plate &cathode( is lead &0b( which is of grey colour.

"hen the cell supplies current to a load &discharging(, the chemical

action that takes place forms lead sulphate &0b94:( on both the

plates with water being formed in the electrolyte. After a certain

amount of energy has been withdrawn from the cell, both plates are

transformed into the same material and the specific gravity of the

electrolyte &/1so:( is lowerd.the cell is then said to be discharged.



There are several methods to ascertain whether the cell is discharged

or not.

To charge the cell, direct current is passed through the cell in

the reverse direction to that in which the cell provided current. This

reverses the chemical process and again forms a lead peroide

&0b41( positive plate and a pure lead &0b( negative plate. At the same

time, &/1so:( is formed at the epense of water,restoring the

electrolyte &/1so:( to its original condition. The chemical changes that

4ccur during discharging and recharging of a lead)acid cell

7ATT!R> 'IR'*IT -IA?RA#@



'IR'*IT -IA?RA# -!TAI<9@

In our project we are using secondary type battery. It is

rechargeable Type. A battery is one or more electrochemical cells,

which store chemical energy and make it available as electric current.

There are two types of batteries, primary &disposable( and secondary

&rechargeable(, both of which convert chemical energy to electrical

energy. 0rimary batteries can only be used once because they use

up their chemicals in an irreversible reaction. 9econdary batteries can

be recharged because the chemical reactions they use are reversible8

they are recharged by running a charging current through the battery,

but in the opposite direction of the discharge current. 9econdary, also

called rechargeable batteries can be charged and discharged many

times before wearing out. After wearing out some batteries can be

recycled.

7atteries have gained popularity as they became portable and

useful for many purposes. The use of batteries has created many

environmental concerns, such as toic metal pollution. A battery is a

device that converts chemical energy directly to electrical energy it



consists of one or more voltaic cells. !ach voltaic cell consists of two

half cells connected in series by a conductive electrolyte.

4ne half)cell is the positive electrode, and the other is the

negative electrode. The electrodes do not touch each other but are

electrically connected by the electrolyte, which can be either solid or

liquid. A battery can be simply modeled as a perfect voltage source

which has its own resistance, the resulting voltage across the load

depends on the ratio of the battery%s internal resistance to the

resistance of the load.

"hen the battery is fresh, its internal resistance is low, so the

voltage across the load is almost equal to that of the battery%s internal

voltage source. As the battery runs down and its internal resistance

increases, the voltage drop across its internal resistance increases,

so the voltage at its terminals decreases, and the battery%s ability to

deliver power to the load decreases.



.1 ir sensor@

Ir transmitter@

0<A9TI' IB5RAR!- <I?/T !#ITTIB? -I4-!@



9'/!#ATI'@



A00<I'ATI4B9@

• 4ptical communications

•9afety equipment

-RA"IB? 54R IR R!'!C!R@

3.3. MOTOR:

-.'.#4T4R 0RIB'I0<!@

A machine that converts direct current power into mechanical

power is known as -.' #otor. Its generation is based on the principle

that when a current carrying conductor is placed in a magnetic field,

the conductor eperiences a mechanical force. The direction if this

force is given by 5leming6s left hand rule.



"4RDIB? 45 A -' #4T4R@

'onsider a part of a multipolar dc motor as shown in fig. when the

terminals of the motor are connected to an eternal source of dc

supply8

&i( The field magnets are ecited developing alternate B and 9

poles.

&ii( The armature conductors carry currents. All conductors

under B)pole carry currents in one direction while all the

conductors under 9)pole carry currents in the opposite

direction.

9uppose the conductors under B)pole carry currents into the plane

of paper and those under 9)pole carry current out of the plane of

paper as shown in fig. 9ince each armature conductor is carrying

current and is placed in the magnetic field, mechanical force acts on

it. Applying 5leming6s left hand rule, it is clear that force on each

conductor is tending to rotate the armature in anticlockwise direction.

All these forces add together to produce a driving torque which sets

the armature rotating. "hen the conductor moves from one side of

the brush to the other, current in the conductor is received and at the



same time it comes under the influence of net pole which is of

opposite polarity. 'onsequently the direction of force on the

conductor remains same.



0RIB'I0<!9 45 40!RATI4B@

In any electric motor, operation is based on simple electromagnetism.

A current)carrying conductor generates a magnetic field8 when this is

then placed in an eternal magnetic field, it will eperience a force

proportional to the current in the conductor, and to the strength of the

eternal magnetic field. As you are well aware of from playing with

magnets as a kid, opposite &Borth and 9outh( polarities attract, while

like polarities &Borth and Borth, 9outh and 9outh( repel. The internal

configuration of a -' motor is designed to harness the magnetic

interaction between a current)carrying conductor and an eternal

magnetic field to generate rotational motion.



<et%s start by looking at a simple 1)pole -' electric motor &here red

represents a magnet or winding with a EBorthE polariation, while

green represents a magnet or winding with a E9outhE polariation(.

!very -' motor has si basic parts )) ale, rotor &armature(, stator,

commutator, field magnet&s(, and brushes. In most common -'

motors, the eternal magnetic field is produced by high)strength

permanent magnets. The stator is the stationary part of the motor ))

this includes the motor casing, as well as two or more permanent

magnet pole pieces. The rotor &together with the ale and attached

commutator( rotate with respect to the stator. The rotor consists of

windings &generally on a core(, the windings being electrically

connected to the commutator. The above diagram shows a common

motor layout )) with the rotor inside the stator &field( magnets.



The geometry of the brushes, commutator contacts, and rotor

windings are such that when power is applied, the polarities of the

energied winding and the stator magnet&s( are misaligned, and the

rotor will rotate until it is almost aligned with the stator%s field

magnets. As the rotor reaches alignment, the brushes move to the

net commutator contacts, and energie the net winding. ?iven our

eample two)pole motor, the rotation reverses the direction of current

through the rotor winding, leading to a EflipE of the rotor%s magnetic

field, driving it to continue rotating.

In real life, though, -' motors will always have more than two poles

&three is a very common number(. In particular, this avoids Edead

spotsE in the commutator. >ou can imagine how with our eample

two)pole motor, if the rotor is eactly at the middle of its rotation

&perfectly aligned with the field magnets(, it will get EstuckE there.

#eanwhile, with a two)pole motor, there is a moment where the

commutator shorts out the power supply. This would be bad for the

power supply, waste energy, and damage motor components as well.

>et another disadvantage of such a simple motor is that it would

ehibit a high amount of torque ErippleE &the amount of torque it could

produce is cyclic with the position of the rotor(.



9o since most small -' motors are of a three)pole design, let%s tinker

with the workings of one via an interactive animation &Fava9cript

required(@



A few things from this )) namely, one pole is fully energied at a time

&but two others are EpartiallyE energied(. As each brush transitions

from one commutator contact to the net, one coil%s field will rapidly

collapse, as the net coil%s field will rapidly charge up &this occurs

within a few microsecond(. "e%ll see more about the effects of this

later, but in the meantime you can see that this is a direct result of the

coil windings% series wiring@

There%s probably no better way to see how an average -' motor is

put together, than by just opening one up. *nfortunately this is



tedious work, as well as requiring the destruction of a perfectly good

motor.

The guts of a disassembled #abuchi 55)GG)0B motor &the same

model that 9olarbotics sells( are available for &on +G lines $ cm graph

paper(. This is a basic )pole -' motor, with 1 brushes and three

commutator contacts.

The use of an iron core armature &as in the #abuchi, above( is quite

common, and has a number of advantages. 5irst off, the iron core

provides a strong, rigid support for the windings )) a particularly

important consideration for high)torque motors. The core also

conducts heat away from the rotor windings, allowing the motor to be

driven harder than might otherwise be the case. Iron core

construction is also relatively inepensive compared with other

construction types.

7ut iron core construction also has several disadvantages. The iron

armature has a relatively high inertia which limits motor acceleration.

This construction also results in high winding inductances which limit

brush and commutator life.

In small motors, an alternative design is often used which features a

%coreless% armature winding. This design depends upon the coil wire



itself for structural integrity. As a result, the armature is hollow, and

the permanent magnet can be mounted !"#!$% the rotor coil.

'oreless -' motors have much lower armature inductance than iron)

core motors of comparable sie, etending brush and commutator

life.

The coreless design also allows manufacturers to build smaller

motors8 meanwhile, due to the lack of iron in their rotors, coreless

motors are somewhat prone to overheating. As a result, this design is

generally used just in small, low)power motors. 7eamers will most

often see coreless -' motors in the form of pager motors.

Again, disassembling a coreless motor can be instructive )) in this

case, my hapless victim was a cheap pager vibrator motor. The guts



of this disassembled motor are available &on +G lines $ cm graph

paper(. This is &or more accurately, was( a )pole coreless -' motor.

3.4. GEAR:

The gear is made out of nylon. The gears used in this project are spur

gears. 9pur gears are the simplest and most common type of gear.

Their general form is a cylinder or disk. The teeth project radially, and

with these Estraight)cut gearsE, the leading edges of the teeth are

aligned parallel to the ais of rotation. These gears can only mesh

correctly if they are fitted to parallel ales

WHEEL AND PINION:

"henever two toothed wheels are in mesh. The large wheel is

called as the gear and the smaller one as the pinion, regardless of

which one is the driver.

GEAR MATERIAL:

Bumerous nonferrous alloys, cast irons, powder)metallurgy and

even plastics are used in the manufacture of gears. /owever steels

are most commonly used because of their high strength to weight

ratio and low cost. 0lastic is commonly used where cost or weight is a



concern. A properly designed plastic gear can replace steel in many

cases8 It often has desirable properties. They can tolerate dirt, low

speed meshing, and EskippingE quite well. #anufacturers have

employed plastic to make consumer items affordable. This includes

copy machines, optical storage devices, C'Rs, cheap dynamos,

consumer audio equipment, servo motors, and printers.

3.& RAILWAY TRACK:

Rail tracks are used on railways &or railroads(, which, together

with railroad switches &or points(, guide trains without the need for

steering. Tracks consist of two parallel steel rails, which are laid upon

sleepers &or cross ties( that are embedded in ballast to form the

railroad track. The rail is fastened to the ties with rail spikes, lag

screws or clips such as 0androl clips.

The type of fastener depends partly on the type of sleeper, with

spikes being used on wooden sleepers, and clips being used more on

concrete sleepers.

*sually, a base plate tie plate is used between the rail and

wooden sleepers, to spread the load of the rail over a larger area of

the sleeper. 9ometimes spikes are driven through a hole in the base



plate to hold the rail, while at other times the base plates are spiked

or screwed to the sleeper and the rails clipped to the base plate.

9teel rails can carry heavier loads than any other material.

Railroad ties spread the load from the rails over the ground and also

serve to hold the rails a fied distance apart &called the gauge.(

Rail tracks are normally laid on a bed of coarse stone chippings

known as ballast, which combines resilience, some amount of

fleibility, and good drainage. 9teel rails can also be laid onto a

concrete slab &a slab track(. Across bridges, track is often laid on ties

across longitudinal timbers

'/A0T!R)IC

EQUIPMENT USED

:.+ COMPONENTS AND ITS SPECIFICATION

The railway track crack detector consists of the following

components to full fill the requirements of complete operation of the

machine.

+. Track

1. 7attery

. 'ontrol unit



:. #otor

2. ?ears

C'()t%* -+

WORKING PRINCIPLE

CHAPTER-V

WORKING PRINCIPLE

In this project we are using the sensor to find out the crack in

the track8 this will be useful for the production of track and Track

maintenance. Track needs regular maintenance to remain in good

order, especially when high)speed trains are involved. Inadequate

maintenance may lead to a Eslow orderE being imposed to avoid

accidents Track maintenance was at one time hard manual labour,

requiring teams of labourers who used levers to force rails back into

place on steep turns, correcting the gradual shifting caused by the

centripetal force of passing trains. 'urrently, maintenance is

facilitated by a variety of specialied machines.



In our project we are using the machine with the help of sensor

used to find the crack in the track. The sensor is placed in the front of

the front wheel and the controlled by the control unit. "hen the

moving of the rear wheel with the help of motor with the gear

arrangement the total model is move on that time the sensor send the

signal to the control unit where the crack is in the track are not.

CHAPTER -+

MERITS

MERITS

<ow cost

Reliable

'ompact in sie



CHAPTER-,

APPLICATIONS

It is applicable in the production industries and the

track maintenance

CHAPTER-I

CONCLUSION

The project carried out by us made an impressing task in the

field of railway department. It is very useful for the workers work in

the production of track.

This project will reduce the cost involved in the concern. 0roject

has been designed to perform the entire requirement task at the

shortest time available.



BIBLIOGRAPHY

+. -esign data book )0.9.?.Tech.

1. #achine tool design handbook ='entral machine tool

Institute, 7angalore.

. 9trength of #aterials )R.9.Durmi

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