Design And Construction Of An Infrared Protected Fence

The project is on an infrared based fence protecting alarm system used in places like homes, shopping malls, hotels and theatres for detecting movement of a human being close to the fence or an intruder attempting to burglarize an environment via the fence.

This project proposes a system of automatic sensing any body movement object near the fence. This is achieved with help of a PIR (Passive Infrared) sensor which detect an infrared emitting signal from a live body from a considerable distance. When a body approaches within the operating range of the sensor, it sends a logical command through an alarm indicating that someone is approaching the fence. If there is no further movement within the PIR operating range the alarm will automatically stop.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

CHAPTER ONE

INTRODUCTION

1.1      BACKGROUND OF THE PROJECT

• AIM OF THE PROJECT
• OBJECTIVE OF THE PROJECT
• PURPOSE OF THE PROJECT
• APPLICATION OF THE PROJECT
• LIMITATION /PROBLEM OF THE PROJECT

CHAPTER TWO

LITERATURE REVIEW

• REVIEW OF PIR SENSORS AND ITS APPLICATION
• THE ROLE OF SENSORS IN YOUR HOME SECURITY
• TYPES OF MOTION SENSORS
• OTHER MOTION SENSOR FEATURES
• REVIEW OF THE RELATED STUDY

CHAPTER THREE

SYSTEM DESIGN

• SYSTEM CIRCUIT SCHEMATIC
• OPERATION OF THE SYSTEM
• CIRCUIT DESCRIPTION
• DESCRIPTION OF COMPONENTS USED

CHAPTER FOUR

TESTING AND RESULTS

• CONSTRUCTION PROCEDURE AND TESTING
• INSTALLATION OF THE COMPLET DESIGN
• ASSEMBLING OF SECTIONS
• TESTING OF SYSTEM OPERATION

CHAPTER FIVE

• CONCLUSION
• RECOMMENDATION
• REFERENCES

CHAPTER ONE

1.1                                                        INTRODUCTION

The need for having home protection has always been there. But in the recent times, considering a dramatic rise in petty crimes like robbery and theft, the need has been more strongly felt to have a fool proof protection of the belongings and the family members. Home security has gone a long way in the last few decades. It was in the hands of a guard who manually provided surveillance during nights in the earlier days, but it was not fool proof as it was only normal for him to have momentary lapse of concentration.

The guard was also susceptible to sleep at times. It was then that home alarm system based upon electronic circuits were developed which proved to be highly reliable and were appreciated by the people as they were relieved from constant monitoring of their homes.

An infrared based fence protecting system is one of the home alarm which uses passive infrared (PIR) energy to recognize the movement of object, such as a person walking near the fence. It is most effective in detecting when the heat mass moves across its field of vision.

This project proposes a system of automatic fence protecting system by sensing any body movement near the fence. This is achieved with help of a PIR (Passive Infrared) sensor. A live body generally emits infrared energy which is sensed by the PIR sensor from a considerable distance. This sensing signal is fed to an integrated circuit to operate an alarm.

1.2                                               OBJECTIVE OF THE STUDY

The main objective of this work is to design a device that will trigger an alarm when sensing any body movement near the fence.

1.3                                         SIGNIFICANCE OF THE PROJECT

Infrared protected fence circuit operates with the help of passive infrared sensor which is also called optic or motion sensors. These sensors might be mounted on or above the fence or built on the top or the sides of the frame of iron fence.

When these optic or motion sensors sense motion nearby, they trigger the alarm. Automatic door alarm has many useful purposes, which is why you can find them in many different types of locations.

The use of infrared makes it easy to construction; it also saves the power consumption and is low cost.

It is a great method of keeping intruders out of your facility.  But, also, it allows for better security if intruder do break in.  Alarms will sound, but the intruder won’t realize that they tripped it until it’s too late.  Then, the security system will work it is magic to catch the perpetrator.

1.4                                          APPLICATION OF THE PROJECT

This device not just used for home security. In industrial fields, they are used on assembly lines to keep track of the number of products and to shut down dangerous equipment if a person gets too close. Here are a few other ways this device is used:

• To open and close automatic Doors
• It can be used as an object detector
• To turn on lights when a person enters a room
• Ideal applications include support of boundary fences, gates, lanes or access routes. Installing them behind perimeter fences gives increased protection for vandal attacks.
• From supermarkets to airports and many types of large buildings, infrared make it easier for people to get into and out of buildings. They are especially helpful for people who are handicapped.

1.5                                                 SCOPE OF THE PROJECT

Generally, in security systems, infrared or laser transmitters and receivers are used. But these methods are cost effective. This work explains about PIR based fence protecting system in which PIR sensor is used instead of transmitter or receiver. This saves the power consumption and is low cost.

When someone or an intruder touches or goes too close to the fence, then it intercepts the first slot of the PIR sensor. This causes a positive differential change between the two bisects. When a human body leaves the sensing area, the sensor generates a negative differential change between the two bisects. The infrared sensor itself is housed in a hermetically sealed metal to improve humidity/temperature/noise/immunity. There is a window which is made of typically coated silicon material to protect the sensing element.

This work is based on PIR sensor with an IC that produces alarm. The PIR sensor detects the IR radiations emitted from the humans and it produces a digital output.

1.6                                 PROBLEM/LIMITATION OF THE PROJECT

This device sensor has some problem:

• It has a limited distance to detect the human/object
• If the sensor is not mounted securely, normal vibration, sign, plants and neon light can trigger the alarm.
• It cannot detect the small objects such as insects or animals.

The reliability of a PIR sensor may also be affected by rapid environmental changes and direct sunlight. Also, things like a fireplace, and direct wind from an air conditioner or heater. This is because a PIR sensor actually detects changes in infrared energy – specifically, the “heat energy” emitted by normal human skin temperature.