10-11-2012, 06:19 PM
ACTIVE INFRARED MOTION DETECTOR FOR HOUSE SECURITY SYSTEM
ACTIVE INFRARED MOTION DETECTOR FOR HOUSE SECURITY SYSTEM.pdf (Size: 1.45 MB / Downloads: 162)
ABSTRACT
Nowadays, house security system becomes the best solution to overcome
house intrusion problem when user is not in house. As we know, there are many
types of house security system which is too expensive and difficult to use. For that
reason, an effective house security system at low cost is built where user can also
program the security system by their own. This project is focusing on developing a
house security system with an active infrared motion detector which is controlled by
microcontroller Intel 8051. The overall project is divided into two parts. The first
part is concern on the hardware development where all electronics component are
connected via the circuit design using wrapping technique. An active infrared, the
magnetic sensor, and keypad are the input components while buzzer, indicator, and
LCD display are the output components where it’s all controlled by controller circuit.
The second part is base on software programming to operate the hardware structure.
Program for security system based on microcontroller Intel 8051 assembly language
is assemble using ASM51 assembler to get the binary file thus, to load into external
memory of the hardware structure via serial communication. The process of
downloading and executing the program is done using HyperTerminal’s
communication software to the microcontroller serial port. In order to achieve the
best house security system, more detectors or sensors can be connected to the
microcontroller output port where it can be reprogram by user using their personal
computer at home. As the result, the infrared motion detector is capable to detect
motion while the microcontroller is capable to control the whole operation of the
security system.
INTRODUCTION
Background
Motion detection is the action of sensing physical movement in a given area.
Motion can be detected by measuring change in speed or vector of an object in the
field of view. This can be achieved either by mechanical devices that physically
interact with the field or by electronic devices that quantifies and measures changes
in the given environment.
There are two device of motion detection which is the mechanical device, and
the other one is electronic device. In the mechanical device, a tripwire is a simple
form of motion detection. If a moving objects steps into the tripwire's field of view
then a simple sound device like bells may alert the user. Mechanical motion
detection devices can be simple to implement, but at the same time, it can be
defeated easily by interrupting the devices' mechanics like "cutting the wire”.
While in electronic device, the electronic motion sensing such as motion
detectors, can prevent such mechanical intervention. The principal methods by which
motion can be electronically identified are optical detection and acoustical detection.
Infrared light or laser technology may be used for optical detection.
Motion detection devices, such as motion detectors, have sensors that detect
movement and send a signal to a sound device that produces an alarm or switch on
an image recording device. There are motions detector which employ cameras
connected to a computer which stores and manages captured images to be viewed
over a computer network.
The applications for such detection are detection of unauthorized entry,
detection of cessation of occupancy of an area to extinguish lighting, and detection of
a moving object which triggers a camera to record subsequent events. The motion
detector is thus a basic idea of electronic security systems.
Project objective
The objective of this project is to build a house security system using
microcontroller Intel 8051 based on active infrared motion detection.
1.3 Project scope
This project concentrates on a development of an active infrared motion
detector for house security system. To develop the whole project, it consists of three
methods which are the concept of security system, the electrical structure, and the
software programming.
The concept of security system is on the detection of movement using active
sensor to trigger alarm controlled by the microcontroller Intel 8051. The electrical
structure consist of two systems which are the active infrared circuit that used to
detect or sense motion and the microcontroller Intel 8051 circuit, used to control the
whole operation of the security system. While the software programming is base on
the microcontroller Intel 8051 instruction sets. It contains a program designed for a
security system as an interaction to operate the electrical structure.
Literature review
Motion detectors are mainly used in security systems [4]. It is typically
positioned near exterior doorways or windows of a building to monitor the area
around it. Since motion detectors are so flexible and have so many uses, it offers
feelings of protection and security for the average homeowner as well as commercial
organizations [4].
An electronic motion detector is a device used to detect any physical
movement in a given area and transforms motion into an electric signal. It consist of
sensor that electrically connected to other devices such as security system, lighting,
audio alarms, and other applications. Motion sensors are used in a wide variety of
applications and as a result, many different types of motion sensors are available
including the infrared sensor.
Infrared sensors are widely known in the arts of intrusion detection and in fire
or smoke detection. It is a device that often used in automatic light switches and
security systems to turn on a light or to activate some other form of alarm or warning
indicator when a person enters a monitored area [4]. The infrared sensors have
basically two forms: active and passive. [4]
An active infrared detector includes a radiation source and an infrared sensor
which is sensitive to interruptions in the radiation sensed from the source. [4] These
detectors are used as intrusion detectors by providing a path of radiation from the
source to the sensor in a place where the path is likely to be interrupted by an
intruder.
The proposed active infrared method of motion detection has the advantage
of fast speed response of a relatively large sensor. This advantage permits simpler
optical system design, especially for wide fields of view. Besides, it is insensitivity to
mechanical and acoustic noise, which presents substantial problems in the passive
infrared (PIR) sensors. Low production cost is another advantage of these active
infrared detectors. [4]
Passive infrared motion detection detects heat energy radiated or emitted by
an object, such as a body of a person, moving across a field of view of a heat sensor
of the motion detection system. It is generally use an optical collection system and
multiple sensing elements of alternating polarity to create a detection pattern in the
volume of interest.
PIR detectors employ a group of radiation sensors coupled through amplifiers
to a logic circuit. The radiation sensors detect changes in ambient infrared radiation.
The detection system has an electrical circuit operatively coupled to the heat sensor
for producing a detection signal in response to the heat sensor detecting a change of
temperature caused by the body heat of a person entering the detection pattern.
PIR motion detectors are perhaps the most frequently used home security
device. [4] Passive IR motion detectors are usually designed to provide an indication
to an alarm panel in response to detecting IR that is indicative of motion of the
object. The alarm panel is responsive to receipt of the breach indication to cause an
alarm condition to occur.
The other motion detector used in security system is an ultrasonic motion
detector. It is commonly used for automatic door openers and security alarms [4]. It
is inexpensive and can operate with narrow beam-widths. The ultrasonic transducers
are the sensor that used in ultrasonic motion detector. It can be used to detect motion
in an area where there are not supposed to be any moving objects. This type of
motion detector is most commonly used in burglar alarm systems since they are very
effective in this application [4].
In an ultrasonic motion detector, there are two transducers; one emits an
ultrasonic wave and the other picks up reflections from the different objects in the
area. The reflected waves arrive at the receiver in constant phase if none of the
objects in the area are moving. If something moves, the received signal is shifted in
phase. A phase comparator detects the shifted phase and sends a triggering pulse to
the alarm.