APROJECT REPORT

ON

“Advance Railway System”“Advance Railway System”SUBMITTED TO

RAJIV GANDHI PROUDYOGIKI VISHVIDYALAYA BHOPAL (M.P.)

(UNIVERSITY OF TECHNOLOGY OF MADHYA PRADESH)

IN THE PARTIAL FULFILMENT OF THE REQUIREMENT FOR THEAWARD OF THE DEGREE OF

BACHELOR OF ENGINEERINGIN

ELECTRONIC & COMMUNICATION

2006-2010

SUBMITTED BY

VIKALP KULSHRESTHA [0903EC061114]

Under the Guidance of:

Mr. MAHENDRA YADAV Lact. of Electronics Deptt MPCT GWALIOR-06

DEPARTMENT OF ELECRONICS & COMMUNICATION

MAHARANA PRATAP COLLEGE OF TECHNOLOGYGWALIOR (M.P.)

1

MAHARANA PRATAP COLLEGE OF TECHNOLOGY GWALIOR -474006(M.P.)

ELECTRONICS & COMMUNICATION ENGINEERING DEPARTMENT

CERTIFICATE

This to certify that this project entitled “ADVANCE RAILWAY MONITORINGAND CONTROLLING SYSTEM ” being submitted by VIKALP KULSHRESTHA in partial fulfillment for the award of the degree of Bachelor of Engineering in( Electronics & Communication) of Rajiv Gandhi Proudyogiki Vishwavidhayalaya, Bhopal (University of Technology of Madhya Pradesh), is a record of students own work carried out by them under my guidance and supervision. To the best of my knowledge, the matter presented in this project has not been submitted for the award of any other degree, diploma or certificate.

UNDER THE GUIDANCE OF

Lect. MAHENDRA YADAV Prof.SHALINI SAHAYDept. of electronics & Communication Reader & Head of DepartmentM.P.C.T. GWALIOR (M.P.) Deptt. Of Electronics & Comm. M.P.C.T,Gwalior(M.P.)

Dr. SahayPrincipal

M.P.C.T. Gwalior (M.P.)

2

CONTENETS

ACKNOWLEDGEMENT

INTRODUCTION

REVIEW / ELEMENTS

MICROCONTROLLER

DESIGNING PHASE

APPLICATION / CONCLUSION

REFERENCES

3

ACKNOWLEDGEMENT

IT is with great pleasure that, WE present this report” ADVANCE RAILWAY MONITORING AND CONTROLLING SYSTEM” . WE great fully acknowledge my profound in debetness towards my esteemed guide ER. MAHENDRA YADAV , Departments of Electronics & Communication Engineering,M.P.C.T. , Gwalior (M.P.) for his valuable guidance, excellent supervision and constant encouragement during the entire course of work. We are greatful to Prof. SHALINI SAHAY, Head Of Department in Electronics and Communication Engineering, M.P.C.T., Gwalior (M.P.) for having provided excellent academic atmosphere in this institution, which made the endeavour possible.

We are greatful to Dr. Sahay Principal,M.P.C.T., Gwalior (M.P.)for having provided excellent academic atmosphere in thus institution, which made the endeavour possible.

We also express sincere gratitude to the Librarian staff and Electronics & Communication staff, M.P.C.T, Gwalior(M.P.) for providing helpful study materials.

Last but not the least, we would like to thank our beloved parents for their encouragement and co-operation during the time of working through this project. Also, thanks to all the friends for their encouragement & support.

GWALIOR DATE: 29 MARCH 2010 VIKALP KULSHRESTHA

4

Chapter 1

Introduction

1.1 About the Project

Safety should be primary consideration while building a railway network. The safety of rail network typically depends on the use of track side signaling and traffic monitoring system in regulating the safe passage of trains. With the widespread use of software systems, railway signaling has achieved extremely high levels of reliability. The weakest link is typically the driver’s response to track-side signals. The main aim of this project is to propose an idea for the complete automation of railways system. Presently, as such no centralized system is there through which we can track the location of trains from any centre point. Also the railway gate is operating manually. So if we proposed an automatic system then there will be definitely a less chance of accidents at crossing. Thirdly, there is manual detection of faults in the fish-plates. This manual detection of broken fish-plates can also be made fully automatic. Hence it provides security to the railways from any derailment of trains due to broken tracks. This is a Microcontroller based project.For this we will use a microcontroller, sensors, and a lot of electronic devices. This project can be modified for other security purposes if required. This is a project of Automation of Railway Control System. A small model is made to show that how we can control railway crossing gate automatically, tracking the train in the whole rail network and fish-plate broken indicators on LCD Display.

1.2 SCOPE OF THE PROJECT

The Automation of the Railways is such that it save energy, provide full safety from the loss of man and material. So this type of system can be applied in any railways. This will be very helpful in the development of any country both financially and technically.

Automatic Railway Traffic signaling is a system used to control railway traffic safely, essentially to prevent trains from accidents. Being guided by fixed sensors, trains are uniquely susceptible to collision; furthermore, railway crossing gates automatically shuts down as soon as the train reaches there.

Trains cannot derail if the fish plates are not broken, so on each fish plates sensors are provided to make sure if any fish plate gets broken. This principle can form the basis of most railway safety systems.

5

So at the end we found that it is very Beneficial Powerful Efficient Compact It is very beneficial as it saves lots of electrical energy. It is very powerful as it can control any electrical device. It is very efficient because it is of very low cost. And it is also very compact because a very small circuit is required for making this.

1.3 PRESENT RAILWAY SYSTEM IN INDIA

1> Presently railway crossing gates are operated manually. A man posted on crossing gate site pays the duty of shutting down and opening of railway gates.

Problems Faced-:

a> sometimes the road traffic becomes so busy that it becomes impossible for the many posted on the duty to shut down the gates in correct time

b> In many remote areas railway crossing gates are open and no person is located for the operation of gates and hence leading to accidents.

c> Many times gates are shut down too early leading to wastage of time of peoples struck at crossing

Accidents caused due to this scenario-:

a> March 20, 1982 – A Mangalore-to-New Delhi train slams into a tourist bus at a level crossing in Andhra Pradesh, snapping the bus in two, killing at least 59 people on the bus and injuring 25 others

b> May 3, 1995 – Nalgonda rail disaster, 35 people are killed in a collision with a tractor in Nalgonda district in Andhra Pradesh.

c> May 14, 1996 – Alappuzha level crossing crash, 35 wedding guests are killed when their bus is run down by a train in Kerala.

d> May 25, 1996 – Varanasi level crossing crash, 25 people die in a collision with a tractor at Varanasi

2> Presently as such no centralized system is there through which we can track the location of trains from any center point.

6

Problems Faced -:

a> As trains cannot be centrally located, often more then one train runs on the same track in opposite direction leading to accidents

Accidents caused due to this scenario-:

a.> August 2, 1999 – Gauhati rail disaster, Two express trains collide head-on in Gauhati, India. Over 285 people are killed.

b.>December 2, 2000 – Sarai Banjara rail disaster, a crowded commuter train crashes into a derailed freight train in the Punjab. More than 45 are killed

c.> April 21, 2005 – Vadodara rail collision, India: collision between freight and passenger express train; 18 are killed.

3> Presently manual checking of fishplates is done at particular intervals

Problems faced -

a> As the fished plates are manually checked and that too not regular, may accidents took place due to derailment

Accidents caused due to this scenario-

a> September 14, 1997 – Bilaspur rail disaster, 120 people are killed in a derailment on a bridge in Bilaspur province in Madhya Pradesh

b> April 4, 1998 – Fatuha train crash, Atleast 11 people die in derailment near Patna (near Fatuha station) on the Howrah-Delhi main line as Howrah-Danapur Express derails between between Fatuha and Bankaghat stations.

c> June 4, 1999 - Kazipet train crash, Twelve are killed in a derailment at Kazipet in Andhra Pradesh.

1.4 EFFECT ON INDIAN ECONOMY DUE TO TRAIN ACCIDENTS

Indian railways suffers from deteriorating finances and lack the funds for future investment. Last year, India spent $28 billion, or 3.6% of GDP, on infrastructure. The main problem plaguing the Railways is the high accident rate which stands at about three hundred a year. Although accidents such as derailment and collisions are less common in recent times, many are run over by trains, especially in crowded areas. Indian Railways have accepted the fact that given the size of operations, eliminating accidents is an unrealistic goal, and at best they can only minimise the accident rate. Human error is the primary cause (83%) blamed for mishaps. The Konkan Railway route suffers from landslides in the monsoon season, which has caused fatal accidents in the recent past.

7

Contributing to the Railways' problems are the antiquated communication, safety and signalling equipment. One area of upgrading badly required is an automated signalling system to prevent crashes. A number of train accidents happened due to a manual system of signals between stations. However, the changeover to a new system would require a substantial investment. It is felt that this would be required given the gradual increase in train speeds and lengths, that would make accidents more dangerous. In the latest instances of signalling control by means of interlinked stations (e.g., Chennai - Washermanpet), failure-detection circuits are provided for each track circuit and signal circuit with notification to the signal control centres in case of problems. However, this is available in a very small subset of the total Railways. Aging colonial-era bridges and century-old tracks also require regular maintenance and upgrading.

In many places, pedestrians, vehicles or cyclists may cut across the tracks to save time, causing a safety hazard to the railways. Most railway land in India is not fenced or restricted in any way, allowing free trespass. In rural areas, cattle and other animals may stray onto the tracks, posing a much more serious safety hazard to fast-moving trains.

1.5 EFFECT ON INDIAN ECONOMY AFTER THE IMPLEMENTATION OF THIS PROJECT

Last year, India spent $28 billion, or 3.6% of GDP, on infrastructure and every year this amount increases by 20% .The main cause of this expenditure is due to accidents. Human error is the primary cause (83%) blamed for mishaps and derailment of railway tracks caused due to faults in fishplates. With the implementation of this project we can put a stop to the expenditure thrown every year on accidents. Moreover with the implementation of this project people will feel more secure and safe while travelling through trains.

The rate of train accidents are increasing rapidly every year, there is a need to put a stop on this. Though the implementation of our project will be costly but it’s a one time investment and the amount of investment can be easily recover within few years with respect to the expenditure thrown every year on Indian railways due to accidents.

1.6 Modules of the Project:

1. Automatic Controlling of the Railway Crossing gate.

2. Automatic Detection of faults in Fish-Plate.

3. Tracking the Train in the Rail Network.

1.7 Schematic Diagram of the Project:

8

9

Chapter 2

Review/Background Material

2.1 Railway Crossing Gate:

2.1.1 Manual crossings

2.1.1.1 Manually controlled gate (MG)

Access is protected by the presence of gates. As the train approaches a railway employee will close the gates across the road and allow the train to pass over the crossing. The gates will then be opened across the railway line to allow the free flow of road vehicle traffic to resume. On particularly quiet roads the gates are sometimes maintained 'closed to road' and opened when required if no train is approaching. 

2.1.1.2 Manually controlled barrier (MCB)

Protected by barriers, across both carriageways of the road and are operated by a railway employee. The operation of the road traffic lights signals and audible warning devices is interlocked into the signaling system. Typically, the crossing operator would be situated within a 50m clear view distance of the crossing.

2.1.1.3 Manually controlled barrier protected by closed circuit television (MCB-CCTV)

It is similar to the Manually Controlled Barrier. The only difference is that the railway employee uses a CCTV system to monitor and control the operation of the crossing.

In our Project we are proposing an automatic control of railway crossing

2.1.2 ARCC – Automatic Railroad Crossing ControllerThe Automatic Railroad Crossing Controller (ARCC) is designed to operate signals and/or barriers as a train approaches a crossing, and then switch the signals off (and raise any barriers) once the end of the train is clear of the crossing.

As shown in the schematic diagram the LDR’s(Light Dependent Resistors) have been used along the railway crossing track as a sensing devices. When the LDR’s are illuminated through sunlight a signal has been detected that there is no train near the railway crossing.

Now when the train passes over the LDR’s a signal is sent to the microcontroller to shut down the crossing gate.

Instead of using LDR’s as a sensing device we can also use infra-red sensors.

10

The system works by having four infra-red light beams across the track, as shown in the diagram below. The source of each infra-red beam is a suitable LED, positioned on one side of the track, and its light is detected on the opposite side of the track by a matching phototransistor. Each of the four beams will be broken in sequence by the train as it travels along the track and over the crossing.

If a

train is approaching from the left, for example, the crossing signals, etc., are activated as the front of the train (locomotive) breaks beam 'A'. The signals stay activated until the last car in the train has passed through beam 'C', and the beam is intact again. Similarly, for a train approaching from the right, the crossing signals are activated as beam 'D' is broken, and continue until the complete train has passed through beam 'B'.

It is important to appreciate that all four beams are broken as the train moves through. When travelling from left to right, breaking beam 'B' before beam 'D' effectively tells the ARCC to ignore the breaking of beam 'D' until the train has passed completely through the set of sensors, i.e. until the last car has travelled beyond beam 'D'. The ARCC is then returned to its "Ready" state, where the breaking of either beam 'A' or 'D' will trigger the crossing signals. A similar sequence applies for trains travelling from right to left, where the breaking of beam 'C' stops the ARCC from re-triggering the crossing signals as soon as beam 'A' is broken.

2.1.3 Limitation of Automatic Railway Crossing Controller:

The ARCC is designed to handle only a single track, but it is possible to handle a railroad crossing with dual tracks, by fitting a second ARCC module, with its own set of four infra-red beam sensors. The two ARCCs are coupled together so that a train running in either direction, on

11

either track, will operate the crossing signals. If you have trains running across the crossing on both tracks simultaneously, then the first train to reach an 'outer' sensor (its own 'A' or 'D') will activate the crossing signals/barriers. These will stay active until BOTH trains are clear of their own inner sensors (the relevant 'B' or 'C').

2.2 Tracking the Train in the Rail Network:

Presently, as such no centralized system is there through which we can track the location of trains from any center point. In our system LDR’s acting as sensors will be located on each station railway track and as soon as the train will pass that station the LDRs will give the signal to the microcontroller that the train has been passed from that station and an LED will be glow determining the name of the station.

2.2.1 Alternatives to Track Circuits:Here are some alternatives to the track circuits described above:

2.2.1.1 Single-point train detectors - set and reset system This refers to the use of sensors positions at the start of a section to detect a train entering the section. This can be implemented in various and creative ways:

1. Micro switches - positioned so that the wheels or flanges close the switch. 2. Photo sensors - positioned so that a train either breaks a light beam or obscures the sun. 3. Proximity detectors - these detect metal close by. 4. Induction loops - these detect moving metal bodies close by.

Each of the above has its own advantages and disadvantages. But each achieve the same result - they detect the presence of a train at a single point on the track. The problem with this is that this method cannot be relied heavily upon to determine train occupation. This is especially the case when you consider the partnered requirement of this system. A single-point detector might be used to indicate an train entering a section. You then need another single-point detector to indicate the train has left the section. Here lies the problem. When the train activates the 'reset' detector, only the first axle of the train has left the section - most of the train is still in the section. The train will be regarded as having left the section even though it hasn't. If another train then enters the section and activates the 'set' detector, the first train might 'reset' the system straight away, making any signaling misleading.

2.2.1.2 Multi-set and reset system This design uses the same single-point detectors as the set/reset system. The 'set' detector works in the same way - it detects a train entering a section ans 'sets' the circuit to its 'occupied' state. At

12

the end of the section, the 'reset' detector does two things: 1) it triggers a time delay, at the end of which, resets the circuit to the 'clear' state. 2) If the the reset detector is reactivated before the time delay ends, the time delay is reset and starts again, keeping the system in the 'occupied' state. This allows the train to fully exit the section before the system regards it as 'clear'. The downfall of the system is a train which stops just after activating the reset detector. The time delay will end before the rest of the train retriggers it and the system will produce a false 'clear' state.

2.2.1.3 Timing systems In some cases, a single-point detector is connected to a timer and used to prevent a certain operation such as points being changed, etc. Obviously, this system cannot protect a train that stops on the points.

2.2.1.4 Disadvantages of Track Circuits

Track circuit systems are a very simple - in installing and maintaining. They do, however, have some downfalls.

1. Because the system relies on electricity passing between the trains' wheels and the rail, rust on the surface of the rails can cause a problem. Very bad rust will prevent the current flow through the axles and therefore the system will not be able to detect a train. Note that for rust to cause a problem, it must affect each axle of the train. Normally, even on a very rusty track section, with a reasonable length train, at least some of the wheels are making good contact with the rail.

2. If the wire connecting the earth rail to the circuitry is broken, or if the earth rail itself looses electrical contact at some point in a section (like at a fish plate), the portion of the section which is no longer earthed will no longer be able to detect trains. This is unlikely due to the strong connections used. Note that if either of the wires connecting to the ends of the positive rail is broken, the system will detect a train in the section even if there isn't one. This is less of a problem because it is 'fail-safe'.

2.2.1.5 Definition of 'fail-safe'

A 'fail-safe' system is one which, by virtue of its design, will fall into a 'safe' state if it fails. It does not mean the system will not fail or be faulty. Rather, it means that when the system does fail (it is always assumed to fail at some point in time), the failure will not cause an unsafe state to exist.

2.2.1.6 Advantages of Track Circuits:

13

Simple circuit - requires only a relay, a ballast resistor and connections. The power supply is shared between all track circuits (up to a limit).

1. Inexpensive and easy to install. Track connections are simple compared with single-point detection systems.

2. Very reliable - relays and ballast resistors have large life-spans. 3. Is virtually 'fail-safe'. 4. Is the basis of more complicated signal interlocking systems that would otherwise be

unreliable?

2.3 A BRIEF INTRODUCTION TO MICROCONTROLLER

14

Microcontrollers, as the name suggests, are small controllers. They are like single chip computers that are often embedded into other systems to function as processing/controlling unit. For example, the remote control you are using probably has microcontrollers inside that do decoding and other controlling functions. They are also used in automobiles, washing machines, microwave ovens, toys ... etc, where automation is needed.

2.3.1 KEY FEATURES OF MICROCONTROLLERS:

HIGH INTEGRATION OF FUNCTIONALITY

Microcontrollers sometimes are called single-chip computers because they have on-chip memory and I/O circuitry and other circuitries that enable them to function as small standalone computers without other supporting circuitry. FIELD PROGRAMMABILITY, FLEXIBILITY

Microcontrollers often use EEPROM or EPROM as their storage device to allow field programmability so they are flexible to use. Once the program is tested to be correct then large quantities of microcontrollers can be programmed to be used in embedded systems. EASY TO USE

Assembly language is often used in microcontrollers and since they usually follow RISC

architecture, the instruction set is small. The development package of microcontrollers often

includes an assembler, a simulator, a programmer to "burn" the chip and a demonstration board.

Some packages include a high-level language compiler such as a C compiler and more

sophisticated libraries.

2.3.2 MICROCONTROLLER (AT89C51)

8051 microcontroller has 128 bytes of RAM, 4K bytes of on-chip ROM, two timers, one serial port, and four ports (each 8-bits wide) all on a single chip. The 8051 is an 8-bit processor i.e. the CPU can work on only 8 bits of data at a time. The fixed amount of on-chip ROM, RAM, and number of I/O ports in microcontroller makes them ideal for many applications in which cost and space are critical.

The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash programmable and erasable read only memory (PEROM). The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer, which provides a highly flexible and cost-effective solution to many embedded control applications.

2.3.2.1 FEATURES:-

15

Interrupt control

Buscontrol

Serial port

ETC.

Osc

CPU

4 I/O Ports

On-chip RAM

On-chip ROM for program code

Timer 0

Timer 1

Cou

nte

r Inp

uts

P0 P1 P2 P3 TXD RXD

ADDRESS/DATA

External Interrupts

• Compatible with MCS-51™ Products

• 4K Bytes of In-System Reprogrammable Flash Memory

– Endurance: 1,000 Write/Erase Cycles• Fully Static Operation: 0 Hz to 24 MHz

• Three-level Program Memory Lock

• 128 x 8-bit Internal RAM

• 32 Programmable I/O Lines

• Two 16-bit Timer/Counters

• Six Interrupt Sources

• Programmable Serial Channel

• Low-power Idle and Power-down Modes

2.3.2.2 BLOCK DIAGRAM:-

16

2.3.2.3 PIN CONFIGURATION:-

2.3.2.4 PIN DESCRIPTION:

VCC - Supply voltage.

GND - Ground.

Port 0 - Port 0 is an 8-bit open-drain bi-directional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high-impedance inputs.

Port 0 may also be configured to be the multiplexed low-order address/data bus during accesses to external program and data memory. In this mode P0 has internal pull-ups.

Port 0 also receives the code bytes during Flash programming, and outputs the code bytes during program verification. External pull-ups are required during program verification.

Port 1 - Port 1 is an 8-bit bi-directional I/O port with internal pull-ups.

The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups. Port 1 also receives the low-order address bytes during Flash programming and verification.

Port 2 - Port 2 is an 8-bit bi-directional I/O port with internal pull-ups.

The Port 2 output buffers can sink/source four TTL inputs.

When 1s are written to Port 2 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses

17

(MOVX @ DPTR). In this application, it uses strong internal pull-ups when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register.

Port 2 also receives the high-order address bits and some control signals during Flash programming and verification.

Port 3 - Port 3 is an 8-bit bi-directional I/O port with internal pull-ups.

The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pull-ups. Port 3 also serves the functions of various special features of the AT89C51 as listed below:

RST - Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device.

ALE/PROG - Address Latch Enable output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming.

18

PORT PIN ALTERNATE FUNCTIONS

P3.0 RXD (serial input port)

P3.1 TXD (serial output port)

P3.2 INT0 (external interrupt 0)

P3.3 INT1 (external interrupt 1)

P3.4 T0 (timer 0 external input)

P3.5 T1 (timer 1 external input)

P3.6 WR (external data memory write strobe)

P3.7 RD (external data memory read strobe)

In normal operation ALE is emitted at a constant rate of 1/6 the oscillator frequency, and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external Data Memory.

If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.

PSEN - Program Store Enable is the read strobe to external program memory. When the AT89C51 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory.

EA/VPP - External Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset.

EA should be strapped to VCC for internal program executions.

This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming, for parts that require 12-volt VPP.

XTAL1 - Input to the inverting oscillator amplifier and input to the internal clock operating

circuit.

XTAL2 - Output from the inverting oscillator amplifier.

2.4 OSCILLATOR CHARACTERISTICS:

XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier, which can be configured for use as an on-chip oscillator. Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven.

Note: C1, C2 = 30 pF +/- 10 pF for Crystals

= 40 pF +/- 10 pF for Ceramic Resonators

There are no requirements on the duty cycle of the external clock signal, since the input to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications must be observed.

19

D1

D2

D3

D4

1

B 2

A

3 4

7805

1000 F + +

--

5 V DC

AC SupplyLoad

+ -

D1

D2

D3

D4

1

B 2

A

3 4

2.5 POWER SUPPLY

Most of the digital circuits operate on 5 volt DC supply which is obtained by the following circuit. The power supply circuit consists of a step down transformer, bridge rectifier and 7805 voltage regulator IC.

2.6.1 BRIDGE RECTIFIERS

Bridge rectifier circuit consists of four diodes arranged in the form of a bridge as shown in figure.

2.6.1.1 OPERATION:

During the positive half cycle of the input supply, the upper end A of the transformer secondary becomes positive with respect to its lower point B. This makes Point1 of bridge positive with respect to point2. the diode D1 & D2 become forward biased & D3 & D4 become reverse biased. As a result a current starts flowing from point1, through D1 the load & D2 to the negative end.

During negative half cycle, the point2 becomes positive with respect to point1. Diode D1 & D2 now become reverse biased. Thus a current flow from point 2 to point1.

20

AC Supply

7805

1 3 2

2.6.2 TRANSFORMER:

Transformers are a major class of coils having two or more windings usually wrapped around a common core made from laminated iron sheets.

It has two coils named primary & secondary. If the current flowing through primary is fluctuating, then a current will be induced into the secondary winding. A steady current will not be transferred from one coil to other coil.

Transformers are of two types:

1. Step up transformer

2. Step down transformer

In power supply we use step down transformer. We apply 220V AC on the primary of step down transformer. This transformer steps down this voltage to 9V AC. We give this 9 V AC to rectifier circuit, which convert it to 5V DC.

1. Input Voltage - 220V(ac)

2. Output Voltage - 9V(ac)

3. Cycle - 50-60Hz

4. Max Load-60 W

5. Min. Load-20 W

6. Input Current – 0.4 Amp

7. Output Current – 11.6 Amp

2.6.3 REGULATOR:

7805 IC is used as regulator in 5V power supply.

IN 7805 pin no.1 is input pin through which non-regulated signal is applied. Pin no.3 is grounded & the regulated output is taken from pin no.2.

2.7 RELAYS

21

1 - IN

2 - OUT

It is often desirable or essential to isolate one circuit electrically from another, while still allowing the first circuit to control the second.

For example, if you wanted to control a high-voltage circuit from your computer, you would probably not want to connect it directly to the a low-voltage port on the back of your computer in case something went wrong and the mains electricity ended up destroying the expensive parts inside your computer.

One simple method of providing electrical isolation between two circuits is to place a relay between them, as shown in the circuit diagram of figure 1. A relay consists of a coil that may be energized by the low-voltage circuit and one or more sets of switch contacts, which may be connected to the high-voltage circuit.

2.7.1 How Relays Work

In figure 2a the relay is off. The metal arm is at its rest position and so there is contact between the Normally Closed (N.C.) switch contact and the 'common' switch contact.

If a current is passed through the coil, the resulting magnetic field attracts the metal arm and there is now contact between the Normally Open (N.O.) switch contact and the common switch contact, as shown in figure 2b.

2.7.2Advantages of Relays

The complete electrical isolation improves safety by ensuring that high voltages and currents cannot appear where they should not be.

22

Relays come in all shapes and sizes for different applications and they have various switch contact configurations. Double Pole Double Throw (DPDT) relays are common and even 4-pole types are available. You can therefore control several circuits with one relay or use one relay to control the direction of a motor.

It is easy to tell when a relay is operating - you can hear a click as the relay switches on and off and you can sometimes see the contacts moving.

2.7.3 Disadvantages of Relays

Being mechanical though, relays do have some disadvantages over other methods of electrical isolation:

Their parts can wear out as the switch contacts become dirty - high voltages and currents cause sparks between the contacts.

They cannot be switched on and off at high speeds because they have a slow response and the switch contacts will rapidly wear out due to the sparking.

Their coils need a fairly high current to energise, which means some micro-electronic circuits can't drive them directly without additional circuitry.

The back-emf created when the relay coil switches off can damage the components that are driving the coil. To avoid this, a diode can be placed across the relay coil.

2.7.4 Choosing a Relay

When choosing a relay to use in a circuit, you need to bear in mind properties of both the coil and the switch contacts. Firstly, you will need to find a relay that has the required number of switch poles for your application. You then need to make sure that the switch contacts can cope with the voltage and current you intend to use - for example, if you were using the relay to switch a 60W mains lamp on and off, the switch contacts would need to be rated for at least 250mA at 240V AC (or whatever the mains voltage is in your country).

Also of importance is the material that the switch contacts are made of - gold is good for low-voltages, whereas tungsten is suitable for switching high voltages and currents.

Finally, you need to choose a relay that has a coil that can be energized by your low-voltage control circuit. Relay coils are generally rated by their voltage and resistance, so you can work out their current consumption using Ohm's Law. You will need to make sure that the circuit powering the coil can supply enough current, otherwise the relay will not operate properly.

2.7.5 The Latching Relay Circuit

If a relay is connected as shown in figure 3, it will become 'latched' on when the coil is energized by pressing the Trigger button. The only way to turn the relay off will then be to cut the power supply by pressing the Reset button (which must be a push-to-break type).

23

The technical name for this type of behavior is 'bistable', since the circuit has two stable states for its output - on and off. Bistable circuits can also be constructed using many other components, including the 555 timer IC and transistors.

The latching circuit can be described in the following diagram:-

What's the point of this circuit? The Normally Open switch contact of the relay could also be connected to a device such as a motor, as shown by the dotted connections in figure 3. The device will then run indefinitely until some event (maybe triggered by the device) momentarily presses the Reset button, thereby turning off the coil ready for the Trigger button to be pressed again.

This system could be used in a model which needs a 'Push to Operate' button. A motor and gearing system in the model can be used to press the Reset button to cut the power to the relay coil after the model has been running for a certain amount of time, or until a certain event has occurred. Of course, you would have to be sure that there was enough momentum in the mechanism that the button is released ready for the next cycle.

2.8 LIGHT DEPENDENT RESISTORS

LDRs or Light Dependent Resistors are very useful especially in light/dark sensor circuits. Normally the resistance of an LDR is very high, sometimes as high as 1000 000 ohms, but when they are illuminated with light resistance drops dramatically.

The animation opposite shows that when the torch is turned on, the resistance of the LDR falls,

24

allowing current to pass through it.

This is an example of a light sensor circuit:

When the light level is low the resistance of the LDR is high. This prevents current from flowing to the base of the transistors. Consequently the LED does not light.However, when light shines onto the LDR its resistance falls and current flows into the base of the first transistor and then the second transistor. The LED lights.

The preset resistor can be turned up or down to increase or decrease resistance, in this way it can make the circuit more or less sensitive.

Light dependent resistors are electronic components where the resistance of the device decreases with increasing light intensity. They can also be called LDRs, photo resistors or photoconductors.

LDR's are made of a high resistance semiconductor. If light falling on the device is of high enough frequency, photons absorbed by the semiconductor give bound electrons enough energy to jump into the conduction band. The resulting free electron (and its hole partner) conduct electricity, thereby lowering resistance.

In intrinsic devices, the only available electrons are in the valence band, and hence the photon must have enough energy to excite the electron across the entire band gap. Extrinsic devices have impurities added, which have a ground state energy closer to the conduction band - since the electrons don't have so far to jump, lower energy photons (i.e. longer wavelengths and lower frequencies) will suffice to trigger the device.

2.8.1 APPLICATIONS:

25

LDRs come in many different types. Inexpensive cadmium sulfide (CdS) LDRs can be found in many consumer items such as camera light meters, clock radios, security alarms and street lights. At the other end of the scale, Ge:Cu photoconductors are among the best far-infrared detectors available, and are used for infrared astronomy and infrared spectroscopy.

2.9 LCD Display

2.9.1 Liquid Crystal Display:

Frequently, an 8051 program must interact with the outside world using input and output devices that communicate directly with a human being. One of the most common devices attached to an 8051 is an LCD display. Some of the most common LCDs connected to the 8051 are 16x2 and 20x2 displays. This means 16 characters per line by 2 lines and 20 characters per line by 2 lines, respectively.

Fortunately, a very popular standard exists which allows us to communicate with the vast majority of LCDs regardless of their manufacturer. The standard is referred to as HD44780U, which refers to the controller chip which receives data from an external source (in this case, the 8051) and communicates directly with the LCD.

2.9.2 Hitachi 44780 BACKGROUND

The 44780 standard requires 3 control lines as well as either 4 or 8 I/O lines for the data bus. The user may select whether the LCD is to operate with a 4-bit data bus or an 8-bit data bus. If a 4-bit data bus is used the LCD will require a total of 7 data lines (3 control lines plus the 4 lines for the data bus). If an 8-bit data bus is used the LCD will require a total of 11 data lines (3 control lines plus the 8 lines for the data bus). The three control lines are referred to as EN, RS, and RW. The EN line is called "Enable." This control line is used to tell the LCD that you are sending it data. To send data to the LCD, your program should make sure this line is low (0) and then set the other two control lines and/or put data on the data bus. When the other lines are completely ready, bring EN high (1) and wait for the minimum amount of time required by the LCD datasheet (this varies from LCD to LCD), and end by bringing it low (0) again. The RS line is the "Register Select" line. When RS is low (0), the data is to be treated as a command or special instruction (such as clear screen, position cursor, etc.). When RS is high (1), the data being sent is text data which should be displayed on the screen. For example, to display the letter "T" on the screen you would set RS high. The RW line is the "Read/Write" control line. When RW is low (0), the information on the data bus is being written to the LCD. When RW is high (1), the program is effectively querying (or reading) the LCD. Only one instruction ("Get LCD status") is a read command. All others are write commands--so RW will almost always be low.

26

Finally, the data bus consists of 4 or 8 lines (depending on the mode of operation selected by the user). In the case of an 8-bit data bus, the lines are referred to as DB0, DB1, DB2, DB3, DB4, DB5, DB6, and DB7.

The different instructions available for use with the 44780 are shown in the table below:

27

The bit descriptions for the different commands are:

"*" - Not Used/Ignored. This bit can be either "1" or "0"

Set Cursor Move Direction:

ID - Increment the Cursor After Each Byte Written to Display if Set

S - Shift Display when Byte Written to Display

Enable Display/Cursor

D - Turn Display On(1)/Off(0)

C - Turn Cursor On(1)/Off(0)

B - Cursor Blink On(1)/Off(0)

Move Cursor/Shift Display

SC - Display Shift On(1)/Off(0)

RL - Direction of Shift Right(1)/Left(0)

Set Interface Length

DL - Set Data Interface Length 8(1)/4(0)

N - Number of Display Lines 1(0)/2(1)

F - Character Font 5x10(1)/5x7(0)

Poll the "Busy Flag"

BF - This bit is set while the LCD is processing

Move Cursor to CGRAM/Display

A - Address

Read/Write ASCII to the Display

D – Data

2.9.3 Managing the LCD

Six basic functions are required to efficiently manage the LCD. These are:Initializing, writing commands, reading the address and busy flag, and writing displaycharacter data. The collaboration diagram shown in Figure 8 describes the relationship ofthese six functions. Other functions may be necessary if you go beyond displaying simple text messages on the LCD.

28

The actions of the six basic functions will be explained in below:

2.9.4 AN EXAMPLE HARDWARE CONFIGURATION

As we've mentioned, the LCD requires either 8 or 11 I/O lines to communicate with. For the sake of this tutorial, we are going to use an 8-bit data bus--so we'll be using 11 of the 8051's I/O pins to interface with the LCD. Let's draw a sample pseudo-schematic of how the LCD will be connected to the 8051.

29

Reading Data back is best used in applications which required data to be moved back and forth on the LCD (such as in applications which scroll data between lines). The "Busy Flag" can be polled to determine when the last instruction that has been sent has completed processing. In most applications, I just tie the "R/W" line to ground because I don't read anything back. This simplifies the application because when data is read back, the microcontroller I/O pins have to be alternated between input and output modes. For most applications, there really is no reason to read from the LCD. I usually tie "R/W" to ground and just wait the maximum amount of time for each instruction (4.1 msecs for clearing the display or moving the cursor/display to the "home position", 160 usecs for all other commands). As well as making my application software simpler, it also frees up a microcontroller pin for other uses. Different LCDs execute instructions at different rates and to avoid problems later on (such as if the LCD is changed to a slower unit), I recommend just using the maximum delays given above.

30

Chapter 3

Designing Phase

3.1 Circuit Layout:

31

3.2 Explanation of the Circuit

The complete circuit can be divided into 4 small circuits.

First one is the sensing circuit that contains all the LDR’s sensors and few transistors within it. This part of the circuit is mainly used to identify the train on the railway track. Working: To detect the train on the railway track whether the train is at some station or near the crossing gate LDR’s have been used. The sensing circuit containing LDR sends a Logic Low signal to the Microcontroller denoting that the train is there above the sensing device. When there is no train above the sensing circuit a Logic High signal is sent to the Microcontroller.

Similarly if the fish-plate is broken a Logic Low signal is sent to the Microcontroller and if there is no fault in the fish plate a Logic High signal is continuously being sent to the Microcontroller.

The output of this sensing circuit becomes the input of the Microcontroller. Microcontroller is programmed using a Keil C Compiler and connected to the output circuits like relay and motor circuit and buzzer circuit and interfaced with LCD display.

The Second Circuit contains the Transformer and the Voltage regulator. This part of the circuit is mainly used to obtain different power levels according to the requirement of the components, used in the circuit.Working: Transformer is being used to convert the 220V AC power supply to a 12V DC power supply. Similarly, the Voltage Regulator is being used to convert the 12V DC power supply to 5V DC power supply.

The Third circuit contains a Buzzer, Transistor, and two LED. This part of the circuit is mainly used to activate the Buzzer, in case the fish-plate is broken.Working: In the circuit, if the fish-plate is broken then the Buzzer will be activated and keeps blowing until the faults in the Fish-Plates are corrected. One of the LED’s will be ON when the system detects a fault in the fish-plate also the location of the broken fish-plate is displayed on the LCD.

The Fourth circuit contains Transistors, four relays and two Motor. This part of the circuit is mainly used to control the working of the motor.Working: Here we are using four relays and two motors. Motors are being used to shut the railway crossing gate to block the road traffic from both sides of the railway track. Relay1 and Relay2 are for Motor1.Relay1 for moving the Motor1 clockwise and Relay2 for rotating the motor anti-clockwise. Similarly Relay3 and Relay4 are for Motor2 for moving the motor clockwise and anti-clockwise respectively. Transistors seem to be working as a power amplifier (in the range from 5V to 12V). Thus the relay switches are used to open and close the motor.

32

3.3 Flowchart:

33

START

Microcontroller reads signal from station sensor circuit.

Display

“Welcome “(Line 1)

“Automated Railway

Microcontroller reads signal from Fish-Plate

Microcontroller reads signal from Crossing

Is there any Fault?

Switch on the Buzzer

Close the Railway Crossing gate.

Display

“Fault in fish-plate No. “ (Line 1)

Is train near the railway

Display

“Railway Crossing No. x is Closed. “(Line 1)

Open the Railway Crossing gate.

Display

“Train is at Station X “(Line 1)

Start

Start

YES

YESNO

NO

Start

3.4 Keil C Compiler:

In our Project, Microcontroller is programmed using Keil C compiler by a code written in C language.

Keil Software makes C compilers, macro assemblers, real-time kernels, debuggers, simulators, integrated environments, and evaluation boards for the 8051, 251, and C16x/ST10 microcontroller families. Products available from Keil Software include embedded development tools, evaluation software, product updates, application notes, example code, and technical support. More information is available from www.keil.com.

Keil C51 lets you write 8051 microcontroller applications in C and still get the efficiency and speed of assembly language. C51 language extensions give you full access to all resources of the 8051. It is the most efficient, reliable 8051 development platform available today. With support for all 8051 derivatives and full compatibility with the Keil 251 tools, C51. It is the best choice for embedded system software development.

The CA51 Compiler Kit for the 8051 microcontroller family supports all 8051 derivatives including those from companies like Analog Devices, Atmel, Cypress Semiconductor, Dallas Semiconductor, Goal, Hynix, Infineon, Intel, OKI, Philips, Silicon Labs, SMSC, STMicroelectronics, Synopsis, TDK, Temic, Texas Instruments, and Winbond.

The CA51 Compiler Kit includes...

µVision o Integrated Development Environment

The µVision IDE from Keil, combines project management, make facilities, source code editing, program debugging, and complete simulation in one powerful environment. µVision helps you get programs working faster than ever while providing an easy-to-use development platform. The editor and debugger are integrated into a single application and provide a seamless embedded project development environment.

Keil Classic 8051 Compilation Tools

o A51 Macro Assembler The A51 Assembler is a macro assembler for the 8051 family of

microcontrollers. It supports all 8051 derivatives. It translates symbolic assembly language mnemonics into relocatable object code where the utmost speed, small code size, and hardware control are critical. The macro facility speeds development and conserves maintenance time since common

34

sequences need only be developed once. The A51 assembler supports symbolic access to all features of the 8051 architecture.

The A51 assembler translates assembler source files into a relocatable object modules. The DEBUG directive adds full symbolic information to the object module and supports debugging with the µVision Debugger or an in-circuit emulator. In addition to object files, the A51 assembler generates list files which may optionally include symbol table and cross reference information.

o C51 ANSI C Compiler The Keil C51 C Compiler for the 8051 microcontroller is the most popular

8051 C compiler in the world. It provides more features than any other 8051 C compiler available today.

The C51 Compiler allows you to write 8051 microcontroller applications in C that, once compiled, have the efficiency and speed of assembly language. Language extensions in the C51 Compiler give you full access to all resources of the 8051.

The C51 Compiler translates C source files into relocatable object modules which contain full symbolic information for debugging with the µVision Debugger or an in-circuit emulator. In addition to the object file, the compiler generates a listing file which may optionally include symbol table and cross reference information.

Features

Nine basic data types, including 32-bit IEEE floating-point, Flexible variable allocation with bit, data, bdata, idata, xdata, and pdata

memory types, Interrupt functions may be written in C, Full use of the 8051 register banks, Complete symbol and type information for source-level debugging, Use of AJMP and ACALL instructions, Bit-addressable data objects, Built-in interface for the RTX51 real-time operating system, Support for dual data pointers on Atmel, AMD, Cypress, Dallas

Semiconductor, Infineon, Philips, and Triscend microcontrollers, Support for the Philips 8xC750, 8xC751, and 8xC752 limited instruction

sets, Support for the Infineon 80C517 arithmetic unit.

35

o BL51 Code Banking Linker/Locator The BL51 code banking linker/locator combines OMF51 object modules and

creates executable 8051 programs. The linker resolves external and public references and assigns absolute or fixed addresses to relocatable program segments.

The BL51 Linker processes object files created by the Keil C51 Compiler and A51 Assembler and the Intel PL/M-51 Compiler and ASM-51 Assembler. These object modules must adhere to the OMF51 object module specification. BL51 outputs an absolute OMF51 object module that may be loaded into practically any emulator, the Keil µVision Debugger, or the OH51 Object-HEX converter (to create an Intel HEX file).

o OH51 Object-HEX Converter The OH51 Object-HEX converter creates Intel HEX files from absolute

OMF51 object modules. Absolute object files may be created by the following:

The BL51 code banking linker, The A51 assembler, The OC51 banked object converter.

Intel HEX files are ASCII files that contain a hexadecimal representation of your program. They may be easily loaded into a device programmer for writing EPROMs or other memory devices.

Several utilities are available that may help you with your HEX files: HEX2BIN converts an Intel HEX file into a flat BINARY file. BIN2HEX converts a flat BINARY file into an Intel HEX file.

The following documents provide additional information about the different output file formats.

Description of the Intel OMF51 Object Module Format. Description of the Intel HEX File Format.

OC51 Banked Object Converter

The OC51 banked object file converter creates an absolute object module for each code bank in a banked object module. You do not need this utility unless you have created a code banking program using the BL51 code banking linker.

When you create a code banking application, all symbolic and source-level information is maintained in the banked object module and is transferred by OC51 to each individual absolute object module for each code bank.

36

Once you have used OC51 to create the absolute object modules, you may use OH51 to create an Intel HEX file for each code bank.

3.5 Component list:-

DC Motor-Buhler DC Motor

LDRs

Microcontroller(AT89s52)

Relays-JQF(T73)

LCD Display-Hitachi 44780

Voltage Regulator-7805

Transistors-BC548

LEDs

Buzzer

Power Supply

Resistors

General Purpose PCB

37

Chapter 4

Result

4.1 Conclusion:

This project uses the present infrastructure of railways, e.g. present signaling methods and meet all the requirements to have a automatic controlling of the railway traffic. It provides the supervision and control systems for the crossing and station. The system shall guarantee the safety of train operation and prevent the railway and its relevant systems from conflict.

It also provides centralized management for highly shared information between subsystems, fully and effectively utilized means and all relevant information of railway transportation, so as to improve the overall efficiency, prevent the accident that may affect the whole and to ensure harmonic operation of each business subsystem.

The proposed system provide the means for real time inspection, review and data collection for the purpose of maintenance on the movable and fixed facilities for the guarantee of operation safety and maintenance efficiency as well as the safety appraisal decision-making system based on the share of safety data.

The great achievement of modern technologies in each relevant field and the technological development of the railway industry itself have provided railway with feasibility to win higher service quality and faster speed.This user service is used to realize more advanced features of communication-based andLocation-based train control system and integrated dispatching with considering all transportResources including car, rolling stock, track, power supply and so on. This service willExcavate the potential ability of infrastructure to the root.Automation of railways provide integrated train operation management system, intelligentized train operation control system and intelligent zed inspection, diagnosis and maintenance system to realize the high-speed and high-density transportation system.

4.2 FEASIBILITY STUDY

Feasibility is the determination whether or not a project is worth doing. The process followed in making this determination is called feasibility study.

Since the feasibility study may lead to commitment of large resources, it becomes necessary that it should be conducted competently and that no fundamental errors of judgment are made.

Preliminary investigation examine project feasibility, the likelihood the system will be useful to the organization. Three important tests of feasibility are described below:-

4.2.1 Technical feasibility: This is concerned with specifying equipment and software that will successfully satisfy the user requirement.

38

During the analysis of the technical feasibility of the system, it is considered that

• It should produce outputs in a given time.

• It should give quick response under certain condition.

• The hardware should be able to process certain volume of transactions at faster speed.

With the above configuration of hardware system and aforesaid software, the system will be entirely technically feasible. One more important point has also been considered that if the Bank proposes any changes in it’s working conditions, the system should also react to that and it can easily be upgraded

4.2.2 Operational Feasibility: The project has been designed considering all future scopes that can come into the consideration in the near future and also considering that the organization can make some changes in its working environment or operational structure, or it can add some new skill that can be essential in near future.

At this level the project is almost operationally feasible because the system has been designed so efficiently that a person having little knowledge of computers can handle the system very well.

The user may not know every little part of the system but the project should support him in the way that he can easily understand information’s and may respond according to that. It is also considered that the system helps to increase the performance of the banks and by any manner it should not cause an harm.

4.2.3 Economic Feasibility: Economic analysis is the most frequently used technique for evaluating the effectiveness of a proposed system. More commonly known as Cost/Benefit Analysis. The procedure is to determine the benefits and saving that are expected from a proposed system and compare with the costs. If benefits overweigh costs, a decision is taken to design and implement the system. Otherwise, further justification or alternative in the proposed system will have to be made if it is to have a chance to be approved. This is an ongoing effort that improves in accuracy at each phase of the system life cycle.

Above mentioned evaluation of the project has been done to see whether it is economically feasible or not. The result was that the approximated cost is very low considering that the Banks are spending a good amount of money as salary on those employees who manage the all the official works other than the regular works.

Bearing in mind the Cost/Profit Analysis of the system, it can easily be said that after looking at all benefits of the projects, and taking into account its requirement in the E-Banking System, it is economically feasible to have this software in the Banks.

Future Enhancements:

39

The project is made such that any railway security related feature can be added to the project model and hence security level can be achieved more. Some of the futures enhancements can be implemented to this project are given below:

4.3.1 Automatic Station Stop Circuit:

The "Automatic Station Stop Circuit" brings a train to a station stop in two braking steps and then sends the train on it's way after a set period of time.

The first braking step slows the train gradually until it is at the station. The second brake step then stops the train just quickly enough to allow the first or second coach to stop in front of the station.After an adjustable interval the train slowly accelerates to continue its trip.

The following diagram shows the placement of the phototransistors along the track and how the braking steps would be carried out

Automatic Station Stop Sensor Placement

When the train crosses the first sensor the train starts to slow down. The train should be moving 10 to 20MPH when the engine reaches the second sensor. When the engine covers the second sensor the train slows just quickly enough to allow the train to stop with one of the coaches in front of the station.

4.3.2 Automatic Braking System:

40

Automatic braking system can be installed in the trains which is initiated if there is any danger ahead like faults in the fish-plates is not corrected and railway crossing is not closed due to any reason e.g. system failure.

Bibliography

Online Datasheets Referred:

[1] Atmel AT89s52.pdf

41

[2] Transistor BC548.pdf

[3]Voltage Regulator LM7805.pdf

[4] Diode 4007.pdf

Websites Referred:

[1]The model railway, “Project homepage,” 2006, Group of Real-Time and Embedded Systems, Department of Computer Science, Kiel, Germany.

[Online]. Available: http://www.informatik.uni-kiel.de/_railway [2] Mathworks Inc., Simulink – Simulation and Model-Based Design,

Mathworks Inc., 2005. [Online]. Available: http://www.mathworks.com/access/helpdesk/help/pdf doc/simulink/sl using.pdf

[3] R. von Hanxleden, “Lectures: Model-based design and distributed realtimesystems,” http://www.informatik.uni-kiel.de/inf/von-Hanxleden/teaching/ss05/v-rt2/skript.html, 2005.

[4] http://www.embeddedstar.com/software/content/e/embedded168.html

[5] http://www.computer-solutions.co.uk/chipdev/keil.htm

[6] http://microcontrollershop.com/product_info.php?cPath=109_130&products_id=106

[7] http://www.designnotes.com/Merchant2/merchant.mvc?Screen=PROD

[8] http://www.beyondlogic.org/spp/parallel.htm#1

[9] http://www.doc.ic.ac.uk/~ih/doc/par/

[10] http://home.cogeco.ca/~rpaisley4/CircuitIndex.html

[11] http://en.wikipedia.org/wiki/Level_crossing

42