This paper systematically expounds the definition, types, development and application of automobile burglar alarm.

Automobile burglar alarm; electronic guardsystem against theft

With the continuous improvement of people's living standards, cars are increasingly becoming an indispensable part of people's lives. Since the world's first T-Ford car was stolen, car theft has become one of the most common crimes in cities today. With the increase of the number of cars, the number of stolen cars is also increasing year by year, which brings great instability to society. Worrying about car theft has become a problem for every car user. With the popularity of convertibles, car door locks can no longer be foolproof, which further dilutes the concept of car door lock system, and car anti-theft devices have emerged. At present, there are many kinds of electronic anti-theft devices on the market, and the best-selling electronic anti-theft lock 300-400 yuan can be bought. At present, many new cars on the market have been equipped with anti-theft devices for the original cars. Some vehicles have anti-theft chips on their keys, and the unlocking passwords are randomly changed, which makes it impossible for car thieves to unlock the cars by scientific means. Once such keys are lost, they can only take the vehicle's user registration card to the original factory to make a new set of keys. According to the latest technical data, some models have begun to use hidden IC cards instead of car keys. As long as the owner walks within 3 to 5 meters, the anti-theft device will automatically unlock. The owner gets into the car and presses the ignition switch to start the car. When the owner leaves the vehicle for 5 meters, the door will automatically lock.

First, the definition and types of car burglar alarm

(A) the definition of car burglar alarm

Car burglar alarm is a device installed on cars to increase the difficulty and prolong the time of car theft, and it is the patron saint of cars. Through the cooperation between the anti-theft device and the automobile circuit, it can prevent the vehicle from being stolen and infringed, protect the vehicle and realize various functions of the anti-theft device.

(2) Types and characteristics of car burglar alarms.

With the progress of science (teaching cases, test papers, courseware, teaching plans), people have developed various anti-theft devices with different structures to deal with the escalating means of stealing cars. At present, anti-theft devices can be divided into four categories according to their structures: mechanical, electromechanical, electronic and network.

1. mechanical burglar alarm. Early automobile anti-theft equipment was mainly mechanical anti-theft lock. The development of mechanical locks has experienced several technical upgrades. Hook lock, steering wheel lock and shift lock are basically mechanical anti-theft. They mainly achieve the purpose of anti-theft by locking the clutch, brake, throttle or steering wheel and shifting gears, and only prevent theft without giving an alarm. Its advantages are low price, only tens to hundreds of yuan, simple installation, which can deter car thieves or increase the possibility of thieves being found to some extent. The disadvantage is that the anti-theft is not thorough, and it is more troublesome to disassemble every time. When not in use, you have to find a place to put it.

At present, a kind of steering wheel lock with guard plate has been introduced on the market. This kind of lock is hidden and protected by a layer of anti-saw and anti-drilling steel plate. Its material is stronger than the traditional crutch lock, and the lock core is designed more accurately, so it has higher reliability. But the owner must find a space to hide the removed steering wheel; Gear lock is one of the most appreciated anti-theft devices for car owners at present. This anti-theft device is simple and firm. Made of special high-hardness alloy steel, it is anti-prying, anti-drilling and anti-sawing, and adopts nickel-silver alloy lock core and key with the same material. It is extremely difficult to open without the key provided by the original factory. If the key is lost, you can copy it with the original computer card.

2. Electromechanical anti-theft device. With the progress of science (teaching cases, test papers, courseware, teaching plans), an electromechanical anti-theft device (central door lock) has appeared. The central door lock controls the opening or locking of the door locks through electricity, and the driver centrally controls the locking or opening of all the door locks. The central door lock system has the following functions:

When locking (or unlocking) the driver's door lock, other doors and luggage compartments can be locked (or unlocked); If the key locks the door, you can also lock (or open) other doors and luggage compartments; When you need to open a single door lock in the car, you can open the button of the corresponding door lock separately.

3. Electronic burglar alarm. In order to overcome the shortcoming that mechanical locks only guard against theft and don't give an alarm, the electronic alarm anti-theft alarm device came into being. The electronic anti-theft system of automobile is based on the original central door lock, and the control circuit of the anti-theft system is added to control the movement of the automobile and give an alarm at the same time. Electronic anti-theft is an ideal anti-theft device at present. If a thief steals a car or something on the car, the anti-theft system not only has the functions of cutting off the starting circuit, ignition circuit, oil injection circuit, oil supply circuit and speed change circuit, locking the brake and so on. , but also send out different acousto-optic distress signals to give an alarm, which will give the thief a mental blow and prevent the thief from stealing.

Plug-in type, key type and remote control type are all electronic burglar alarms. The feature of remote control of car burglar alarm is that it can remotely control all the functions of burglar alarm, which is reliable and convenient, and can be equipped with functions such as vibration detection, door protection, microwave or infrared probe. With the rapid development of science and technology, the remote control car burglar alarm has added many convenient and practical additional functions, such as remote control of central door lock, remote control of air supply and exhaust, remote control of electric doors and windows, remote control of luggage compartment opening and so on. At present, there are two-way electronic burglar alarms on the market. This kind of burglar alarm can not only control the vehicle remotely by the owner, but also transmit its own status to the owner, such as the door is opened or the window glass is damaged. However, the electronic anti-theft alarm device generally has the phenomenon of false alarm, which does not fundamentally solve the problem of vehicle loss.

4.GPS satellite positioning car anti-theft system. The vehicle anti-theft system based on GPS satellite positioning (or other network systems) silently transmits the alarm information and the position of the alarm vehicle to the alarm center. It has many functions such as vehicle positioning, remote flameout, network query and tracking, vehicle monitoring, road information query, manual navigation and so on. It is an all-round anti-theft system.

Vehicle anti-theft system based on GPS satellite positioning belongs to network anti-theft device, which mainly achieves the purpose of anti-theft by locking ignition or starting. At the same time, the alarm information and the position of the alarm vehicle can be silently transmitted to the alarm center through the GPS satellite positioning system. The vehicle position can be monitored in real time nationwide, and the sound inside the vehicle can be monitored through the on-board mobile phone. If necessary, you can turn off the oil circuit and circuit of the vehicle by mobile phone and lock all the doors and windows. If the GPS anti-theft alarm device is disassembled illegally, it will send out alarm information by itself, but the disadvantage is that it is expensive, and there are not many options for car owners at present.

Second, the development and application of automobile anti-theft device

At present, the automobile anti-theft device has developed from the initial mechanical control to the key control-electronic password-remote control for help-information alarm system, from the simple mechanical key anti-theft technology to the electronic anti-theft and biological (teaching plan, test paper, courseware, teaching plan) characteristic electronic anti-theft. The electronic anti-theft system mainly consists of an electronic control remote controller or key, an electronic control circuit, an alarm device and an actuator. The types of electronic anti-theft system mainly include:

1. Key control type. Open or lock the door lock with the key, and set or remove the anti-theft system at the same time.

2. Remote control. The anti-theft system can remotely control the door lock to open or lock, that is, remotely control the anti-theft or unlocking of the automobile anti-theft system.

3. Alarm type. When the car is stolen, the anti-theft system only gives an alarm, and has no function of stopping the car from moving.

4. Anti-theft alarm and anti-theft system to prevent vehicles from moving. When the car is stolen, in addition to the sound signal alarm, the starting circuit, ignition circuit or oil circuit of the car should be cut off to prevent the car from moving.

5. Electronic tracking anti-theft system. The system is divided into satellite positioning and tracking system (GPS for short) and central control center positioning and monitoring system through walkie-talkie.

Electronic tracking, positioning, monitoring and anti-theft system is a tracking device that uses radio waves to display the location of stolen cars on Braun map and give an alarm to the police. To establish a tracking, positioning, monitoring and anti-theft system, the relevant units need to set up such a set of institutions and a set of special equipment, and it needs 24-hour monitoring. Otherwise, even if the electronic tracking, positioning and monitoring anti-theft system is installed, it will not play an anti-theft role.

(1) key control anti-theft system

The function of the key-controlled anti-theft system is that when the driver locks the door, the circuit of the electronic anti-theft system is connected and the electronic anti-theft system starts to work. Once a thief opens the car door illegally, the electronic anti-theft system will use the horn to call for help on the one hand, and cut off the ignition system circuit on the other hand, making the engine unable to start, thus playing the role of anti-theft alarm.

The electronic key coding control device controls the start of the automobile engine by coding the ignition key to prevent the automobile from being stolen. It mainly consists of a controller consisting of an identification code ignition key, an encoder and an engine control unit. The coded ignition key is embedded with a resistance tube core, and an identification code (resistance value) is arranged in the resistance tube core. This code is stored in the ignition lock cylinder. When the inserted key does not match the stored password, that is, the resistance value does not match the resistance value stored in the ignition lock, the circuit of the ignition system cannot be connected, thus playing the role of anti-theft.

(2) Electronic password anti-theft system

The electronic password of the burglar alarm is the key to open the burglar alarm. On the one hand, the identification codes of burglar alarms are recorded to distinguish the differences of each burglar alarm; On the other hand, it also contains anti-theft function instruction code and data code, which is responsible for turning on or off the anti-theft device and controlling all functions of the anti-theft device.

According to the different password transmission modes, the remote control car burglar alarm is mainly divided into two types: fixed code burglar alarm and code hopping burglar alarm. In the early days, fixed code burglar alarm was mostly used, but it was gradually replaced by code hopping burglar alarm with advanced technology and good burglar alarm effect because it was easy to be deciphered. The principles and characteristics of two different types of burglar alarms are introduced below. 1. Fixed code burglar alarm. The early remote control car burglar alarm was that the host and remote control each had the same set of passwords. The remote controller sends the password and the host computer receives the password, thus completing various functions of the burglar alarm. This cipher transmission mode is called the first generation fixed code transmission mode (hereinafter referred to as fixed code transmission mode). The application of fixed code emission method in automobile burglar alarm is not popular. When the amount of anti-theft alarm is small, it is in a preliminary anti-theft alarm application market, and its safety and reliability are still guaranteed. However, for the market where the use of burglar alarm is mature, this coding method is neither reliable nor safe for three reasons:

(1) The number of passwords is small, and it is easy to have duplicate codes, that is, one remote controller controls multiple vehicles.

(2) If the remote controller is lost, it is extremely unsafe to replace it alone, unless it is replaced with the host, but the cost is too high.

(3) Poor security is also the biggest danger. Passwords are easily copied or stolen, which leads to vehicle theft.

2. Code hopping burglar alarm. For a long time, the fixed code burglar alarm has some unsafe problems, such as small number of passwords, duplicate codes, passwords being easily copied and stolen. Therefore, the code hopping burglar alarm came into being, and its characteristics are as follows:

(1) The password of the remote controller includes not only ID code and instruction code, but also skip code. Code skipping means that the password is based on some coding function. Every transmission, the password will be changed immediately, and the password will not be easily copied or stolen, which is extremely safe.

(2) There are hundreds of millions of password combinations, completely eliminating duplicate codes.

(3) The host has no password, and the host learns the password of the remote controller to realize mutual recognition between the host and the remote controller. If the remote control is lost, it can be replaced safely and at low cost, without worries. (3) Remote electronic anti-theft system

At present, this electronic anti-theft system is widely used in many cars equipped with anti-theft system in the original factory. The remote control electronic anti-theft system uses transmitting and receiving equipment to lock or open the door through electromagnetic waves or infrared rays, that is, to control the anti-theft system to be on duty or released.

There are many kinds of remote control electronic anti-theft systems, such as electromagnetic wave remote control electronic anti-theft system and infrared control anti-theft system. The remote electronic anti-theft system can lock or open the door conveniently and quickly at night without the help of lights.

1. A complete set of remote control car burglar alarm should be composed of the following parts:

(1) Host part: it is the core and control center of burglar alarm.

(2) Induction detection part: It can be composed of sensors or probes. At present, oscillation sensors are widely used, while microwave and infrared probes are rarely used.

(3) Door control part: including front cover switch, door switch and luggage compartment switch.

(4) Alarm part: horn.

(5) Wiring part.

(6) Other parts: including stickers, screws, relays and other accessories, operating instructions and installation wiring diagrams.

2. The function and operation of remote control electric central door lock anti-theft system

(1) Remote car locking and anti-theft settings. Press the corresponding button on the remote control, and the four turn signals will flash once, indicating that the driver's door and luggage compartment are locked. The anti-theft indicator light flashes slowly and continuously, prompting the driver that the car has entered the anti-theft state. In this state, the starting and ignition power is cut off.

(2) Remote unlocking and anti-theft release. Press the corresponding button on the remote control, and the four turn signals will flash twice, indicating that the driver's door and luggage compartment have been unlocked. The anti-theft indicator goes out, indicating that the driver's car has been lifted, and the starting and ignition power supply circuits are back to normal. At the same time, the indoor light is on for 20s, which is convenient for drivers and passengers to get on the bus.

(3) Automatic anti-theft setting. Turn the ignition switch to the OFF position after parking. If any door is opened and then closed, it will be delayed for 3s. After the four turn signals flash five times in a row, they will automatically enter the anti-theft setting state. If the door is opened again within 5s, the system will stop timing. When all the doors are closed again, the system starts recording again, and the four turn signals start flashing again. After 5 seconds, it enters the setting state of the anti-theft system again. If you don't use the key or remote control to lock the car here, the central door lock won't lock the car in case the driver or remote control is left in the car.

(4) Secondary anti-theft setting. If the key corresponding to the remote controller is touched by mistake, the anti-theft will be lifted (at this time, the indoor light will automatically light up for 20s); Or after consciously releasing the burglar alarm, the inner door does not open within 30s, and the system enters the burglar alarm setting state again and locks the door automatically.

(5) anti-theft function. When the ignition switch is turned to the driver's position, the car is robbed or forcibly driven away within the remote control distance, and the robbed driver presses the big key for 3s, and the four turn signals will keep flashing. At the same time, the horn on the car kept ringing to warn the carjackers to stop. If the carjacker abandons the car and escapes, and the car is within the remote control distance, the driver can press the corresponding button to remove the flashing of the turn signal and horn. If the car thief drives away, even if the car is stopped and the key is pulled out, the four turn signals will still flash until the battery is exhausted; When you get on the bus and start again, the starting and ignition power of the car is cut off, and the car can no longer drive. If the key is turned to the ignition position, the horn on the car will start to sound again.

(6) When the anti-theft system is triggered, it will automatically give an alarm, and the system will enter the anti-theft setting state again. In the process of anti-theft setting, if the car forcibly opens the door and luggage compartment or forcibly starts the engine without being released by the remote controller, the four turn signals will automatically flash continuously for 30 seconds to show the alarm. If the system returns to normal, the turn signal will go out automatically after 30 seconds, and the system will enter the anti-theft setting state again. If the system does not return to normal, the turn signal will go out automatically after 90 seconds, and the system will enter the anti-theft setting state again.

(7) Automatically unlock when parking. After parking, the ignition switch is turned to the off position, the central locking system is automatically unlocked, and the indoor light is automatically lit for 20s, which is convenient for drivers and passengers to get off.

(8) Self-check function. After the anti-theft setting, the four turn signals flash once, and the system automatically enters the anti-theft setting, which is also in the self-checking state. In other words, if any door is not closed correctly or fails, the four turn signals will flash 4 times. If the luggage compartment is not closed properly or the luggage compartment switch fails, resulting in a short circuit of the switch, the four turn signals will flash 6 times, prompting the driver to check the fault point. The self-inspection system also divides the four doors and luggage compartment into two inspection areas. That is, the four doors are a detection area, and the luggage compartment is an independent detection area. If one of the detection areas fails, it will not affect the other detection area to perform the anti-theft function.

(9) When the burglar alarm is triggered, it will be automatically memorized and displayed. Any part of the system has been touched during the anti-theft setting time. When the anti-theft is released, the status indicator will flash to remind the driver.

(10) The anti-theft system is deactivated. If the anti-theft system fails, the battery of the remote controller is dead or the car needs maintenance, the anti-theft system must be removed, and the function of remote control of the central door lock in the system can still be used normally. The method is as follows: Turn the ignition switch to the driving range, turn off the release switch, the four turn signals will flash once, and the status indicator will go out after flashing once, indicating that the anti-theft system is in the released state (the anti-theft system cannot be used).

(1 1) The anti-theft system is restored. Turn the ignition switch to the driving range and turn off the release switch. The four turn signals will flash for three times, and the status indicator will go out after flashing for three times, indicating that the anti-theft system can be used normally.

Third, warm tips

The anti-theft system is not omnipotent. Nowadays, many cars are pre-installed with computer anti-theft systems before leaving the factory. When the data of the key chip is consistent with the pre-stored data of the on-board computer, the computer will inform the relevant system to start working and allow the engine to start. Cars equipped with on-board computer anti-theft system do not need to install electronic anti-theft devices. If repeated installation, it is easy to conflict with the anti-theft system installed in the original car; If you must install an extra electronic burglar alarm, please pay attention to separate it from the ignition system, otherwise the engine will not start. If there is any fault, please do not disassemble it yourself. Please go to a professional repair shop and use a professional decoder to clear the fault code and eliminate the fault.