robust railway crack detection scheme

8/10/2019 Robust Railway Crack Detection Scheme

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The major building blocks of this project

Regulated power supply with voltage regulator.

Micro controller

Crystal Oscillator

Reset button

GPS

GSM

MAX 232 interfacing.

RS232 cable

LCD DC motors

LDR sensor

LED indicators


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Robust Railway Crack Detection Scheme (RRCDS) using

LED-LDR Assembly

Micro

controller

Regulated power supply

GPS

Receiver

RS 232

interfacing

Crystal Oscillator

LDR indicators

Reset

GSM

modem

LED indicators

RS 232

interfacing

DC

MotorsDC Motor

Driver


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Types of processors

We have many types of processors in markets in that few are

given below AT MEGA microcontroller

PIC microcontroller

ASIC (application specific microcontroller)

DSP (digital signal processor)

Compare to all controllers PIC microcontroller have more

advantages. So in this project we are using PIC controller to

control the home appliances.


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Microcontroller

A microcontroller is a small computer on a single integrated

circuit consisting of a relatively simple CPU combined with

support functions such as a crystal oscillator, timers, watchdog

timer, serial and analog I/O etc.

Microcontrollers are also used in scientific, high technology,

and aerospace projects.

Microcontrollers are designed for small or dedicated

applications.


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Some microcontrollers may operate at clock rate frequencies

as low as 4 kHz, as this is adequate for many typical

applications, enabling low power consumption (mill watts or

microwatts)

Microcontrollers are used in automatically controlled products

and devices, such as automobile engine control systems,

remote controls, office machines, appliances, power tools, andtoys. By reducing the size and cost compared to a design that

uses a separate microprocessor, memory, and input/output

devices, microcontrollers make it economical to digitally

control even more devices and processes.

A microcontroller can be considered a self-contained system

with a processor, memory and peripherals and can be used

with an embedded system.


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Microcontrollers must provide real time response to events inthe embedded system they are controlling. When certainevents occur, an interrupt system can signal the processor tosuspend processing the current instruction sequence and to

begin an interrupt service routine (ISR, or "interrupt handler").

Embedded processors are usually used to control devices, theysometimes need to accept input from the device they are

controlling. This is the purpose of the analog to digitalconverter. Since processors are built to interpret and processdigital data, i.e. 1s and 0s, they won't be able to do anythingwith the analog signals that may be being sent to it by adevice.

So the analog to digital converter is used to convert theincoming data into a form that the processor can recognize.There is also a digital to analog converter that allows the

processor to send data to the device it is controlling.


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PIC is a family of Harvard architecture microcontrollers made

by Microchip Technology, derived from the PIC1640

originally developed by General Instrument's Microelectronics

Division. The name PIC initially referred to "Peripheral

InterfaceController".

A PIC's instructions vary from about 35 instructions for the

low-end PICs to over 80 instructions for the high-end PICs.

The instruction set includes instructions to perform a variety of

operations on registers directly, the accumulator and a literal

constant or the accumulator and a register, as well as for

conditional execution, and program branching.


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Advantages of microcontroller

Low cost User friendly

Easily available in market

We can reprogram it up to 1000 times

Less power consumption


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OSCILLATOR

An electronic oscillatoris an electronic circuitthat produces a repetitive Electronic signal, often a sine wave

or a square wave.

PIC micro controller internally having 4mhz clock frequency.

We are giving the 20Mhz clock frequency as an external

source for increasing the system performance


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RESET BUTTON

The reset button is a button that when clicked, will

clear all of the fields in the micro controller, and

executes the instructions from the starting address.

A switch placed between the digital input and

ground will short the digital input to ground when it

is pressed. This means the voltage seen at the inputwill be high when the switch is open and low when

the switch is closed.


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Regulated power supply

The major blocks of power supply are given below Transformer

Rectifier

Filter

7805 voltage regulator


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Transformer

Transformer is a electromagnetic device which inducesthe voltage due to magnetic field present between primary

and secondary windings.

It has two windings called as primary winding andsecondary winding. We are giving input 230v input

voltage at primary side. The output of transformer is

9v(ac only).

In this project we are using 9v step down transformer


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We have two types of transformers

1) Step up transformer.

2) Step down transformer.

Step up transformer:

This transformer will step up the voltage that is this

transformer will increase the voltage.

Step down transformer:

This type of transformers will step down the voltage.

That is this will convert high voltage in to low voltage.

Mostly for project purpose we are using only step down

transformer.


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Rectifier

Rectifier is circuit which converts the ac in to dc. We have

two types of rectifier.

1. Full wave rectifier

2. Half wave rectifier

Full wave rectifier again classified as follows

1. Bridge rectifier

2. Cetertapped full wave rectifier

In this project we are using bridge rectifier because the

efficiency of the bridge rectifier is high compare to all

rectifiers.


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Filter

The output of rectifier is not pure DC. It may contain someripple components that is pulsating DC. To eliminate thisripple components which are present in output we are usingfilter.

Filter is a circuit which is used to eliminate the ripples presentin rectified output.

We have many types of filters.

Most of the power supplies are using capacitor filter to filterout the ripples present in output.


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Regulator

The output of filter is not constant output voltage it will varies

according to changes in input but we want constant output

voltage. For this purpose we are using voltage regulator.

Regulator is defined as it is a device which will maintain

constant output irrespective of changes in input.

The most popular regulator series is 78xx series. This series

have more advantages.

We are using 7805 voltage regulator to maintain constant 5v

output voltage irrespective of changes in input voltage.


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GSM GSM, which stands for Global System for Mobile

communications, reigns (important) as the worlds mostwidely used cell phone technology. Cell phones use a cell

phone service carriers GSM network by searching for cellphone towers in the nearby area.

Need of GSM:

1. The GSM study group aimed to provide the followingsthrough the GSM:

2. Improved spectrum efficiency.

3. International roaming.

4. Low-cost mobile sets and base stations (BS)5. High-quality speech

6. Compatibility with Integrated Services Digital Network(ISDN) and other telephone company services.

7. Support for new services.


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Global system for mobile communication (GSM) is a globally

accepted standard for digital cellular communication.

GSMArchitecture:

A GSM network consists of several functional entities

whose functions and interfaces are defined. The GSM network

can be divided into following broad parts.

The Mobile Station (MS)

The Base Station Subsystem (BSS)

The Network Switching Subsystem (NSS)

The Operation Support Subsystem (OSS)


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Following fig shows the simple architecture diagram of GSM

Network.


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The added components of the GSM architecture include the

functions of the databases and messaging systems:

Home Location Register (HLR) Visitor Location Register (VLR)

Equipment Identity Register (EIR)

Authentication Center (AuC)

SMS Serving Center (SMS SC) Gateway MSC (GMSC)

Charge back Center (CBC)

Transcoder and Adaptation Unit (TRAU)


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Following fig shows the diagram of GSM Network

along with added elements.


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GSM network areas:

In a GSM network, the following areas are defined:

Cell:Cell is the basic service area, one BTS covers one cell.Each cell is given a Cell Global Identity (CGI), a number thatuniquely identifies the cell.

Location Area:A group of cells form a Location Area. This isthe area that is paged when a subscriber gets an incoming call.Each Location Area is assigned a Location Area Identity(LAI). Each Location Area is served by one or more BSCs.

MSC/VLR Service Area: The area covered by one MSC iscalled the MSC/VLR service area.

PLMN:The area covered by one network operator is called

PLMN. A PLMN can contain one or more MSCs.


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Advantages of GSM:

1.GSM is already used worldwide with over 450 million

subscribers.

2. International roaming permits subscribers to use one

phone throughout Western Europe. CDMA will work in

Asia, but not France, Germany, the U.K. and other popular

European destinations.

3.GSM is mature, having started in the mid-80s. This

maturity means a more stable network with robust features.

CDMA is still building its network.

4.GSM's maturity means engineers cut their teeth on thetechnology, creating an unconscious preference.

5.The availability of Subscriber Identity Modules, which are

smart cards that provide secure data encryption give GSM

m-commerce advantages.


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GPS(global positioning system)

GPS stands for global positioning system, which provides

unequalled accuracy and flexibility of positioning for

navigation.

The GPS provides continuous three-dimensional positioning

24 hrs a day throughout the world. GPS provides accurate

location and time information for an unlimited number of

people in all weather, day and night, anywhere in the world.

The Global Positioning System (GPS) is a satellite-based

navigation system made up of a network of 24 satellites placed

into orbit


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Components of a GPS:The GPS is divided into three major components

1. The Control Segment

2. The Space Segments

3. The User Segment

GPS satellites circle the earth twice a day in a very precise

orbit and transmit signal information to earth. GPS receiverstake this information and use triangulation to calculate theuser's exact location

GPS receiver must be locked on to the signal of at least threesatellites to calculate a 2D position (latitude and longitude)and track movement. With four or more satellites in view,the receiver can determine the user's 3D position (latitude,longitude and altitude).


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Once the user's position has been determined, the GPS unitcan calculate other information, such as speed, bearing,track, trip distance, distance to destination, sunrise and

sunset time and more.

Its official name is NAVSTAR GPS. GPS is developed bythe United States Department of Defense. Its networkconsists of 24 satellites

Sources of GPS signal errors:

1. Ionosphere and troposphere delays

2. Signal multi path3. Receiver clock errors

4. Orbital errors


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Factors that affect GPS:

1. Number of satellites - minimum number required.

2. Multi path - reflection of GPS signals near the antenna3. Ionosphere - change in the travel time of the signal

4. Troposphere - change in the travel time of the signal

5. Loss of Radio Transmission from Base

6. Radio Frequency (RF) Interference7. Signal Strength - Quality of Signal

GPS Applications:

1. Surveying and Mapping2. Navigation

3. Military


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LDR(light dependent resistor)

LDR is one type of resistor. Depending on light falls on it theresistance of this resistor will be varies.

That is if light falls on LDR then the resistance will increasesand vice versa.

In this project we are using to find the day and night to controlthe street lights. At day time the light falls on LDR soresistance increases due to this the current does not flow in thecircuit.

At night time the light does not falls on LDR at this time theresistance of LDR decreases due to this current flows in thecircuit. And street lights will be on.


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Analog Applications of LDR:

1. Camera Exposure Control

2. Photocopy Machines - density of toner

3. Colorimetric Test Equipment

4. Electronic Scales - dual cell

5. Automatic Gain Controlmodulated light source

6. Automated Rear View Mirror

Digital Applications of LDR:

1. Automatic Headlight Dimmer

2. Night Light Control

3. Oil Burner Flame Out

4. Street Light Control

5. Absence / Presence (beam breaker)

6. Position Sensor


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ADVANTAGES OF LED

Long life : Lifetimes can exceed 100,000 hours, as compared to

1,000 hours for tungsten bulbs

Robustness: No moving parts, no glass

Size : Typical package is only 5 mm in diameter

Energy efficiency : Up to 90% less energy used translates intosmaller power supply required

Versatility: Available in a variety of colors


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Applications of led

Medical Instrumentation

Bar Code Readers

Color & Money Sensors

Electronic Gadgets

Encoders

Optical Switches

Embedded systems Fiber Optic Communication


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LCD DISPLAY

A liquid crystal display (LCD) is a thin, flat electronic visual

display that uses the light modulating properties of liquid

crystals.

Liquid crystal display is very important device in embeddedsystem. It offers high flexibility to user as he can display the

required data on it.

These are used in a wide range of applications, includingcomputer monitors, television, instrument panels, aircraft, cockpit

displays, signage, etc


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Pin No. Name Description

Pin no. 1 VSS Power supply (GND)

Pin no. 2 VCC Power supply (+5V)Pin no. 3 VEE Contrast adjust

Pin no. 4 RS0 = Instruction input

1 = Data input

Pin no. 5 R/W0 = Write to LCD module

1 = Read from LCD modulePin no. 6 EN Enable signal

Pin no. 7 D0 Data bus line 0 (LSB)

Pin no. 8 D1 Data bus line 1






Pin no. 14 D7 Data bus line 7 (MSB)

PIN DESCRIPTION


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Advantages of the Project:

Highly efficient and user friendly design. Easy to operate.

Low power consumption.

Location of the crack can be known using GPS.

Efficient design. Works anywhere in the world (GSM

availability).

Incase of emergency intimation (accident) can

be sent to predefined numbers. To detect the crack using GPS based GSM.

To avoid the accidents at a single track.


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Disadvantages of the Project:

Modem should be properly installed for

proper working of the system.

Poor network signal can decrease theperformance of system.

GPS takes time to get the signal from

satellite, when the system is switched ON.


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Applications of the Project:

VIP vehicle tracking.

Child and animal tracking.

Vehicle Security Applications.

Ambulance tracking.


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QUERIES?


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robust railway crack detection scheme

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