外文翻译
标题：Design and Development of a Smart Auto Intruder Alarm System with GSM Network
作者：M.Ehikhamenle, B.O. Omijeh
日期：2016年
出处：Ehikhamenle M, Omijeh BO. Design and Development of a Smart Auto Intruder Alarm System with GSM Network [J]. IJIRCCE, 2016, 4(12): 20588-20597.
分为2部分：
第一部分为外文原文
第二部分为中文译文
Design and Development of a Smart Auto Intruder Alarm System with GSM Network
M.E h ikhamenle1, B.O. Omijeh1
汽车防盗系统Department of Electronic and Computer Engineering, University of Port Harcourt, Choba, Rivers State, Nigeria1’ABSTRACT :This project is based on the design and construction of an intruder detecting and alerting system. This was achieved using an AT89C52 microcontroller for the control of the other component, a SIM900-GSM module that communicates between the home owner phone and the PIR sensor (motion sensor). The interfacing between the GSM module and the microcontroller was achieved using an IC called MAX232 (this IC converts TTL voltage level (+5V) to RS232 voltage level (plus minus 7.5V) vice versa) and the microcontroller was programmed using assembly language. At the end of this project we were able to design and construct a device that is not only cheap but efficient. We overcome the problem of false alarm by using a PIR sensor (passive infrared: this sensor only respond to infrared emitted from the human body and animals) and after testing, the microcontroller responded to the information sent by the PIR sensor and in the occurrence of intrusion send an alert message to the home owner as well sounding an alarm to alert the neighbours using a buzzer.
KEYWORDS; Intruder Detecting, G S M Module, P.I.R. Sensor
I.INTRODUCTION Security is a prime concern in our day-to-day life. Everyone wants to be as much secure as possible. In recent times the world has experienced an exponential increase in the rate of cri
me. Criminals break into houses on a daily basis around the world carting with huge amount of money and precious items. Sensitive and confidential documents, materials and equipment by corporation are constantly declared missing from where they are kept. So there is a need to provide a device that can detect unauthorized persons in an environment.
In a network or a system, any kind of unauthorized or unapproved activities are called intrusions. An Intruder Detection System (IDS) is a collection of the tools, methods, and resources to help identify, assess, and report intrusions.
Intrusion detection is typically one part of an overall protection system that is installed around a system or device and it is not a stand-alone protection measure (Ngad, 2008). In (Zhang et el, 2003), intrusion is defined as: “any set of actions that attempt to compromise the integrity, confidentiality, or availability of a resource” and intrusion prevention techniques (such as encryption, authentication, access control, secure routing, etc.) are presented as the first line of defense against intrusions.
However, as in any kind of security system, intrusions cannot be totally prevented. The intrusion and compromise of a node leads to confidential information such as security keys being revealed to the intruders. This results in the failure of the preventive security mechanism. Therefore, IDSs are designe
d to reveal intrusions, before they can disclose the secured system resources. IDSs are always considered as a second wall of defense from the security point of view. IDSs are cyberspace equivalent of the burglar alarms that are being used in physical security systems today (Patcha and Park, 2007). As mentioned in (Zhang et el, 2003), the expected operational requirement of IDS s is given as: “low false positive rate, calculated as the percentage of normalcy variations detected as anomalies, and high true positive rate, calculated as the percentage of anomalies detected”.
II.RELATED WORKS Considering the current global security environment, the importance of good physical security is difficult to ignore. Physical security services are becoming a private rather than public individuals and organizations tend to hire private security firms and install security equipment and use the police as the back. According to the Bureau of Labor Statistics (2004), private security officers outnumber police officers by more than 2 to 1 in the United States of America. Recent reports suggest that this trend holds true for both daily security operations responding to terrorism, natural disasters. Physical security has seen less attention and it is primarily an applied field, it has no dedicated line of research. Instead, it is scattered through fields like engineering, computer science, chemistry and physics as well as social sciences such as criminology, sociology and psychology. The different types of existing security systems will be analyzed below. •Electrical Locks
Electric locks come in many forms. The most basic is a Magnetic Lock (commonly called a mag lock). A large electro- magnet is mounted on the door frame and a corresponding armature is mounted on the door. When the magnet is powered and the door is closed, the armature is held fast to the magnet. Mag locks are simple to install and are very attack resistant. But mag locks are also problematic. Improperly installed or maintained mag locks have fallen on people. Also there is no mechanical free egress. In other words, one must unlock the mag lock to both enter and leave. This has caused fire marshals to impose strict codes on the use of mag locks and the access control practice in general. Other problems include a lag time in releasing as the collapsing magnetic field is not instantaneous. This lag time can cause a user to walk into the door. Finally, mag locks by design fail unlocked, that is if power is removed they unlock. This could be a problem where security is a prime concern.
•Electric Strikes replace a standard strike mounted on the door frame and receive the latch and latch bolt. Electric strikes can be simple to install when they are designed for drop-in replacement of a standard strike. But some electric strikes require that the door frame be heavily modified. Electric strikes allow mechanical free egress: As a user leaves, he operates the lockset in the door, not the electric strike in the door frame. Electric strikes can also be either fail unlocked, as a mag lock, or the more secure fail locked. Electric strikes are easier to attack than a mag lock. It is simple to lever the do
or open at the strike. Often the there is an increased gap between the strike and the door latch. Latch guards are often used to cover this gap
•Electric Mortise and Cylindrical Locks are drop in replacements for the door mounted mechanical locks. A hole must be drilled in the door for electric power wires. Also a power transfer hinge is used to get the power from the door frame to the door. Electric mortise and cylindrical locks allow mechanical free egress. Electric mortise and cylindrical locks can be either fail unlocked or fail locked.
•Electrified Exit Hardware, sometimes called panic hardware or crash bars, are used in fire exit applications. The idea is that one simply pushes against the bar to open it, making it the easiest of mechanically free exit methods.
Electrified exit hardware can be either fail unlocked or fail locked. A drawback of electrified exit hardware is their complexity which requires skill to install and maintenance to assure proper function.
•Motor Operated Locks are used throughout Europe. A European motor operated lock has two modes, day mode where only the latch is electrically operated, and night mode where the more secure deadbolt is electrically operated (www.wikipedia).
USER AUTHENTICATION SYSTEMS
When implemented with a digital access system, one of the following access systems or digital authentications systems can be with an electric lock. These however are only a few of the numerous authentication devices available.
•Numerical Codes, Passwords and Passphrases: Perhaps the most prevalent form of electronic lock is that using a numerical code for authentication; the correct code must be entered in order for the lock to deactivate.
Such locks typically provide a keypad, and some feature an audible response to each press. Combination lengths are usually between 4 and 6 digits long. A variation on this design involves the user entering the correct
password or passphrase. A major hindrance however is the fact that users are capable of forgetting their codes.
Forgetfulness is especially common in older people and this system will not be convenient for them. These codes are, in some cases, easy to crack.
•Security Tokens: Another means of authenticating users is to require them to scan or "swipe" a securit
y token such as a smart card or similar, or inter act a token with the lock. For example, some locks can access stored credentials on a personal digital assistant using infrared data transfer methods. However, just as in the case of an ATM card, the magnetic tape tends to wear off with time either resulting to time wasting in accessing a room or the inability of the user to access the room at all.
•Biometrics: As biometrics become more and more prominent as a recognized means of positive identification, their use in security systems increases. Some new electronic locks take advantage of technologies such as fingerprint scanning, retinal
scanning and iris scanning, and voiceprint identification to authenticate users. This is a very secure way of identifying a person’s identity but it is limited by the occurrence of an accident or disfiguration to the part of the body used for identification.
III.MATERIALS AND METHODS The block diagram below shows the sections and the signal flow. The circuit diagram shows the different component required for the system to function properly.
The Circuit Analysis
The motion based security system is made up of the following stages;
i.Power Supply Unit
ii.Input stage: the input stage comprises of;
•Motion sensor
iii.Control stage •Microcontroller
iv.Output stage •Buzzer
•LCD Screen
•Bulb
•G S M module
Fig 3.1 The Block Diagram of the System
A. POWER SUPPLY UNIT
Figure 3.2: Diagram of Power Supply Unit
The power supply serves as the main supply of electrical power to the system. The supply voltage is 220Vac that is step down by a 220Vac/12Vac, 500mA transformer. The 12V AC voltage is then rectified by a bridge rectifier to have a DC output. After the rectification process the remaining AC ripples are filtered off by a bypass capacitor. The output from the bypass capacitor is unregulated thereby causing a drastic voltage drop when a load is connected. To solve this problem an integrated IC chip voltage regulator is used to get fixed o utput.
i. Analysis of Power Supply A 240/24V center tapped step
– down transformer was used, to feed 24V to the circuit. Secondary voltage of transformer = 24V (Vγms ) the peak secondary voltage, V peak =√2 × Vγms ……
3.1
= √2 × 24 = 33.9V
The bridge rectifier diode will rectify the 24V from the secondary of the step down t ransformer.
The full-wave bridge rectifier 5W001 was used because it have a peak inverse voltage of 50V and can pass a peak current of 2A which is suitable for our circuit design.
V L (peαk ) = V (max ) − 2V d (oη) … … … … … … … … … 3.2
Where V L(peak) is the peak to peak voltage of the load
V (max) is the maximum voltage of the alternating current V d(on) is the voltage drop across the bridge rectifier diode
[33.9 − 2(0.7)] = 32.5V
The PIV rating of the diode to be used should be at least PIV = V (mαx ) − V D (oη) … … … … … … … … … 3.3 = 33.9 − 0.7
= 33.2V
Therefore the 50v PIV is far greater than this value 33.2v, thus making it suitable for this design. For a suitable filter capacitor value to be employed the following calculations was considered
Vγ = Io /2fc
Where Vγ = γipple voltαge = 1.0V
f = fγequency = 50Hz
Io
250mA Io = γegulαtoγ output cuγγent = 250mA
Therefore, C = 2fVγ = 2x50x1.0 = 2500 x 10-6 farad = 2500µf. Since 2500µf is not a standard value, 2200µf was used.
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