At the moment, almost everyone when buying a new car can order from a dealer an optional installation of any system. This has become quite ordinary. But there are such options that are already included in the package, and they do not need to pay extra for them.
Among these are SRS system. What is it, and what components enter it? Answers to these questions will learn during our today's article.
SRS - What is it? This system is a complex of elements installed in the car that allow you to reduce the consequences of road traffic accidents for the driver and passengers. According to its classification, SRS Airbag refers to constructive security elements. This means that all its components are not installed (as it can be in the case of air conditioning), but mandatory. And no matter, the top is a complete set or "base", all the same, both cars will contain the same set of passive safety devices.
Thus, SRS is a combination of structural elements that are used to protect passengers and a driver from injury during an accident.
Components of the system
The SRS system may include the following components:
- The safety belt (usually happens three point and is installed on each passenger and driving seat).
- Belts tensioners.
- Emergency battery acb.
- Airbags (in the 90s were considered invisible luxury for motorists).
- Active headrests.
Depending on the brand and model of the machine, SRS may include a number of other devices. For example, it can be a protection system for tipping (like on convertibles), additional fasteners for children's chairs, etc.
Recently, many cars have become equipped with pedestrian protection elements. On some models, even an emergency call system is found.
SRS passive security management
What is this system, we have already found out, now let's look at how it is managed. But here is not so unequivocal. All elements listed above have electronic control that provides effective interaction of various SRS components. What does it mean? Constructively, this system is a set of various measuring sensors, a control unit and actuators. The first perform the function of fixing the parameters in which an emergency situation occurs, and transform them into short electrons. It can be shock sensors, front-row seat positions Chairs and a 3-point seat belt switch switches. As a rule, on each of the sides, the automaker sets 2 such devices that respond to strikes. Also, these sensors are closely related to the active head restraints that are activated when the signal is sent to the active mode.
Thus, each of the components of the passive safety system closely interacts with certain sensors and due to special pulses for a few milliseconds allows airbag to inflate and their other components through the SRS block.
Among the executing devices in the car should be noted as follows:
- Belts tensioners.
- Popatrons of pillows.
- Headrest drive mechanism.
- Control lamp on the car instrument panel, which signals the unasseparated belts.
The activation of each of these components occurs in accordance with the software-based software.
What devices can work with frontal impact?
With a headlamp collision, SRS can activate several security elements at once, depending on its strength. It can be both tensioners and pillows (perhaps, and all together).
With a frontal-diagonal collision, depending on the angle and the scope of the impact force in the system, the system is activated:
- Belts tensioners.
- Front airbags.
- Pillows along with tensioners.
- Left or right airbag.
In some cases (usually, at a speed of more than 60 kilometers per hour), the system can activate all of the above elements, thereby ensuring maximum safety and minimal risk of injury to passengers on both rows of seats, as well as the driver itself.
What devices can work with lateral impact?
In this case, depending on the mechanism of the car, there may be either strap tensioners or side pillows. The latter are usually installed on a car of middle and more prestigious classes. The budgetary machines are equipped only with tensioners, which are triggered when hitting, fixing the human body in the seat.
Also, depending on the strength, the battery is triggered in the machine. Thus, in a collision, the risk of short circuit or the formation of sparks is reduced at all. This makes it possible to reduce the possibility of unauthorized ignition of the vehicle as a result of holes in the gas tank or other deformations of body elements.
What are active head restraints?
These elements have become staffed on cars much later than classic safety belt tensioners. Usually, active head restraints are installed on the backs of the front and rear axles in the cabin. Due to the presence of such elements, the risk of fracture in the area of the cervical area at the rear impact is reduced to a minimum (because it is this area one of the most vulnerable to fractures). Thus, the active head restraints significantly increase the chances of life even when it would seem fatal blows. The first instances of such devices began to install on German "Mercedes". In its design, these head restraints are divided into two groups and can be both active and fixed. In the first case, the head restraint has the ability to adjust in height and angle of inclination. Fully, the same analogues are rigid in the backrest of the seats. However, even such head restraints are perfectly coping with their main function - decrease in lesses in various types of collisions.
So, we found out what the SRS system is in the car and how it acts at different collisions.
Hello everyone! Probably, everyone who at least once went to a more or less modern car noticed the inscription SRS. On the steering wheel or on the torpedo opposite the passenger seat. Many people understand that under this inscription hid the airbag, but as it is deciphering this abbreviation, units know.
Abbreviation SRS. deciphered as " Supplemental Restraint System " Translated it can be interpreted as "d Advanced system " I draw your attention that there is no word about the airbag, a keyword is a system. Why is that? Yes, because by itself the airbag is ineffective, and in rare cases is even dangerous.
Supplemental Restraint System includes the following items: airbags, seat belts, SRS control unit and multiple sensors. Only with the joint and most importantly correct work of all these components, the system is as efficient as possible. With non-fastened security belts, the pillow may simply do not disclose, it will open or not it depends on the specific model of the car and the system's algorithm, which has been developed by the security engineers of a car company.
Why do some manufacturers specifically set up the system so that the pillows are not triggered with non-fastened belts? Everything is very simple. In this case, the triggering of the pillow can cause more harm than unfavorable, because the speed with which the pillow fits 300 km / h . Particularly dangerous airbags for children, if they are not fixed in the children's seat or fixed incorrectly.
Please fasten the seat belts each time you travel. No matter where you are going and at what speed.
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What is the SRS automotive system?
Sometimes the drivers complain that they have no SRS indicator on the dashboard. This is especially true of the owners of cars acquired abroad with mileage. In such situations, experts are advised to check for airbags or see if the contacts attached to this indicator will not depart.
SRS - definition and principle of operation
Really, SRS is a passive security system which is responsible for the condition of all elements providing protection in the event of emergency situations.
SRS (in decoding: Supplementary Restraint System) - a rather complicated system that combines:
- Front and side pillows;
- control modules;
- Various sensors tracking the position of people in the cabin;
- acceleration sensors;
- seat belt pretensels;
- active head restraints;
- SRS system module.
You can still add power sources, connecting cables, data transfer connector, etc.
That is, speaking by a simple language, all these sensors collect information about the movement of the car, about its speed or acceleration, about its position in space, on the position of the seat backs, belts.
If emergency situations arise, for example, the car faces an obstacle at speeds over 50 km / h, the inertial sensors closure the electrical circuit leading to the pillow of airbags, and those are revealed.
The airbag inflation occurs due to dry gas capsules, which are located in the gas generator. Under the action of an electrical pulse, the capsule is melted, the gas quickly fills the pillow and it fits at a speed of 200-300 km / hour and immediately blows away to a certain volume. If the passenger is not fastened with a belt, the blow of such a force can lead to serious injury, so individual sensors register, a person is fastened or not.
Belts pretensioners also receive a signal and stretch the belt stronger so that the person remains in place. The active head restraints move so that passengers and the driver receive the neck injuries.
SRS contacts both the central lock, that is, if the door is locked at the time of the door crash, the signal is fed to the central locking system and the doors are automatically unlocked so that the rescuers can easily get to the victim.
It is clear that the system is configured in such a way that all security tools work only in emergency situations.
SRS does not activate the pyropatrons:
- when colliding with soft objects - snowdrifts, bushes;
- When hitting behind, active head restraints are activated in this situation;
- With lateral collisions (if there are no side pillows).
If you have a modern car equipped with an SRS system, then the sensors will respond to unassembled seat belts or incorrectly adjusted seats and head restraints.
Location of elements
As we have already written above, the passive security system includes a lot of elements that are both in the windscreen space and in seats or mounted in the front torpedo.
Immediately behind the radiator grille is the front sensor of directional overloads. It is arranged according to the principle of the pendulum - if the rate of deviation of the pendulum and its position change dramatically as a result of the collision, the electrical circuit is closed and the signal is fed by wires to the SRS module.
The module itself is in front of the tunnel channel and there are wires from all other elements to it:
- airbag modules;
- Seat back position sensors;
- Belts pretensels, etc.
Even if you just look at the driver's seat, we will see in it:
- driver's side cushion module;
- SRS contact connectors, usually, and wiring itself are referred to as yellow;
- Modules for the belt pretensioners and the piston themselves (they are arranged on the principle of the piston, which is driven and the belt is stronger in case of danger;
- Pressure sensor and backrest position sensor.
It is clear that such complex systems are only in fairly expensive cars, while budget SUVs and sedans are equipped with only airbags for the front row, and it is not always.
In order for the entire system to work correctly, you need to comply with simple rules.
First of all, you need to remember that airbags are disposable, and they must be completely replaced with the pyropatrons after the triggering.
Secondly, the SRS system does not require frequent maintenance, but it is necessary to carry out its complete diagnostics at least once every 9-10 years.
Thirdly, all sensors and items cannot be overheated above 90 degrees. None of the normal drivers will not specifically warm them, but in the summer the surface of the car left in the sun can be very hot, especially the front panel. Therefore, it is not recommended to leave the car on the sun, look for a shadow, use also screens on the front glass to avoid overheating torpedo.
It should also be remembered that the efficiency of the passive security system depends on the correct position of the driver and passengers in the cabin.
We advise you to set up the back of the seat so that its angle of inclination is no more than 25 degrees.
It is impossible to move the chair too close to the airbeares - follow the rules for adjusting the seats, which we recently wrote on our vehicle autoportal.
In cars with SRS, it is necessary to fasten with belts, because in the case of a frontal collision, very serious consequences may be due to a blow of the airbag. The belt will hold your body, which inertia seeks to continue moving forward at high speed.
Possible operation of airbags must be free from foreign objects. Fastening for mobile phones, registrars, navigators or radar detectors Place so that they cannot interfere with pillows to open. It will also be not very nice if your smartphone or navigator will be discarded with a pillow in the face of the side or rear passenger - there were such cases, and more than once.
If there are not only front airbags in the car, but also side, the space between the door and the chair should be free. It is not allowed to use seat covers. It is impossible to rely with force on the pillows, the same applies to the steering wheel.
If it happened that the pillow shot itself in itself - it can happen because of the error in the operation of the sensors or due to overheating - it is necessary to turn on the accident, move onto the roadside, or remain for some time on its strip, without turning out the alarms. At the time of the shot, the pillow heats up to 60 degrees, and the sickness - even more, so for some time they should not be touched.
Since the SRS system has a special power source, designed for about 20 seconds of autonomous work, you need to wait at least half a minute before you begin to diagnose the system.
You can independently activate or deactivate SRS, but it is better to trust this work to specialists who can check with a special scanner reading information directly from the SRS main module.
Video about the principle of operation of the system.
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About what SRS in the car is well known to experienced drivers who own modern cars. However, sooner or later it is necessary to learn from novice motorists, because it often happens that the indicator indicates the malfunction of this system on the instrument panels of their "iron horses". Why this happens and how to act, will be described below, however, it makes sense to consider in general terms the design of the SRS system, and also to understand exactly how it functions.
SRS system in the car
The SRS abbreviation is decrypted as Supplementary Restraint System, and it is indicated by the active safety system of the car. It is she who is responsible for which the state is all the elements that should ensure the protection of the driver and passengers of the vehicle in the event of various emergency situations.
The SRS system includes such components as:
- Airbags (front and side);
- Touch sensors tracking in real time position of people in the car;
- Acceleration and impact sensors;
- Seat belt pretension devices;
- Control modules;
- SRS main module;
- Active headrests.
In addition, the elements of the SRS system design are also connecting cables, autonomous power supplies and connectors.
Front airbags are located immediately before the driver (in the steering wheel) and the front passenger (in Torpedo), and the side are located on the sides, in the backs of the seat and side elements of the body. In their designs there are special pyropathrons filled with dry gas and triggered from electrical pulses.
Sensory sensors (pressure sensor and back position sensor) are located in the seats, and the acceleration sensor (it is often also called the overload sensor) - in the front of the car, directly behind the radiator grille. It is arranged according to the principle of the pendulum, and in the event that its position as a result of the collision changes dramatically, it closes the electrical circuit, which thus generates a control signal transmitted to the SRS main module.
In most cases, it is located in the tunnel channel (or rather - in its front part), and its most important function is to control such elements of the SRS system, as airbag modules and seat belt pretensioners. The latter in the same way as sensory sensors are located in the front seats, equipped with piston sickness: when they are triggered, they are given in motion and stretch the belt very quickly. It goes without saying that the active head restraints are also located on the seats, being mounted in the upper parts of the back.
How SRS works
It should be noted that the SRS system is characterized by a very high response rate, and this allows it to preserve health, and sometimes the life of the driver and passengers of the vehicle in the event of serious accidents. When a car moving at a speed of more than 50 km / h is faced with any obstacle, the inertial sensor is triggered. It closes the electrical circuit, as a result of which the control signal enters the SRS main module. Through it, it is broadcast in airbag modules, as a result of which they are triggered within 300 milliseconds.
At the same time, the signal through the main module of the SRS system and the belts pretensioners, as well as to the active head restraints. As a result, the seat belts are instantly tensioning stronger so that the person does not move forward on the inertia, but remained in place. As for active head restraints, in order to prevent the so-called whip injury, they move forward.
It should be noted that the main SRS module, having received a response signal from the acceleration sensor, sends it to the central locking of the car. This is done to unlock doors and provide free access to the machine of rescuers.
The car SRS system is configured in such a way that its triggering occurs only in truly emergency situations. It does not work, for example, when a collision with bushes or snowy snowdrifts. If it registers the blow from the back, the signal on triggering is sent only to active head restraints, and if the beat follows the side, then only the side airbags (in those cases, of course, if they are installed on this car).
Read also : ASR. - What is it in the car and why it is needed.
Service SRS system
The SRS system of frequent service does not require, but once every ten years it must pass full diagnosis. After the airbags are triggered, they are subject to complete replacement, as they are disposable. When operating the SRS system, it is necessary to ensure that its elements (especially sensors) are not heated above +90 ° C.
It is also necessary to remember that the degree of efficiency of this car passive security system depends largely on how correctly the driver and passengers are located in its cabin. For normal operation of seat belts and active head restraints, it is necessary that the seat backs are tilted at an angle of no more than 25 °. In addition, the seats cannot be seen overly close to safety pillows.
As mentioned above, the SRS system is quite complex in its design, and therefore various errors may periodically occur in its operation. As practice shows, they are most often caused by such reasons as:
- Malfunctions of wiring or contacts;
- Problems with electronics control modules;
- Disconnecting terminals and burning fuses.
Whatever the SRS error is urged, it is not strongly recommended to try to eliminate it yourself. Best of all, when it occurs, go to the maintenance station. Its specialist will conduct a thorough diagnosis of the system and eliminate the problem.
Video on the topic
This term has other values, seePillow
Airbag - Passive security system ( SRS. , SUpplemental REstraint. SYSTEM) in vehicles.
It is an elastic shell, which is filled with air or other gas. Airbags are widely used to mitigate the impact in the case of a car collision. Must be applied with seat belts.
A certain similarity of airbag was equipped with aircraft in the 1940s, the first patents were decorated in the 50s.
In 1964, the Japanese automobile engineer Yasuzaburu Cobori (小 保 三郎) began the development of the "airbag" system for airbags. In its design, an explosive for inflation to inflate the airbag was used, for which he was later awarded with patents in 14 countries. He died in 1975, before he saw a wide distribution of airbag systems. [one]  
American Inventor Allen Brid has created a key component for the use of airbags in cars - ball sensor for determining the collision. He presented his invention in 1967 by Chrysler. At that time, the Americans rarely used safety belts and such innovation, which allows to protect the non-passengers in the event of a frontal collision, was very in demand.
Ford created an experimental batch of cars equipped with airbags in 1971 (Ford Taunus 20m P7B). The first sample airbag in the serial car was presented in 1972, when Oldsmobile Toronado (OldSmobile Toronado) was released, model 1973. In 1974, double airbags were option on some large-sized cars released by BYUKIC units, Cadillac and Oldsmobile. These devices did not receive recognition on the market.
In the 70s, in the party out of 10,000 airbags, General Motors, GM (GEEN Motors, GM), are confronted with seven deaths. It is assumed that one of them happened due to the fault of the airbag. The blow strength was small, however, a heart attack occurred. At that time, such cases were too small in order to reliably establish the effectiveness of airbags, but despite this, for the National Road Safety Administration (NHTSA), there was enough reason to perform with a proposal to install airbags for all manufactured cars.
Then in 1981, Mercedes-Benz reiterated the airbag as an option in its latest model W126. In the system represented by Mercedes, during the accident, the seat belts are first tightened, and then the pillow is deployed. Thus, the airbag no longer positioned as a means of replacing seat belts, but as a method for additional passenger protection.
Airbags gained popularity when Ford and General Motors in the mid-80s presented serial samples, now the airbags became standard equipment. Autoliv, specializing in the development of automotive security systems, patented a side airbag and she also began to appear in the Mid 190s.
July 11, 1984 The US government demanded to equip cars released later on April 1, 1989, the airbag for the driver or automatic security belts (now this technology is not used, it "forced" the driver is fasted).
Despite the introduction of airbags in the car brand "General Motors" in the 70s, in many other cars they began to appear only in the mid-90s.
The first Russian passenger car on which the airbag was installed was the export version of the VAZ-21093 performed by the luxury known as the luxury LADA SAMARA BALTIC GL The assembly of which was carried out at the Valmet plant (Finland) from 1996 to 1998. Since the end of the 2000s, the pillows have become a mandatory element of passive safety in the standard configuration of the LADA brand cars. [four]
In 2006, Honda presented the first motorcycle airbag system installed on the Gold Wing Gold Wing Model Sample.
Pneumatic feeder complements the safety belt, preventing the cervical vertebral fracture, by returning the head of the person to the headrest and thereby keeping the neck of the line. That is why frontal pillows are triggered only with frontal shock + - 10 degrees from the longitudinal axis of the car, so that the head exactly fell into the head restraint. They also reduce the risk of hard injury, distributing the power of the passenger's body.
"A newly conducted study showed that more than 6,000 lives were saved thanks to security pillows." ([one] (inaccessible link) )
Standard shoulder seat belts were actually removed in the production of 70s equipped with airbags, which were called upon to replace belts during front collisions. The airbag on the side of the passenger was located at the bottom of the panel, which allowed her to protect the passenger's knees. The bottom of the panel at a driver's seat also differed in its convexity.
General Motors called its ACRS system (Air Cushion Restraint System). It includes a side airbag for a passenger in the production of 70s and provides two-stage deployment as more than later systems.
The principle of operation is based on the use of a simple accelerometer, initiating a chemical response in a special balloon. As a result of the reaction, a rapid filling of a nylon pillow gas occurs, which reduces overload tested by a passenger at the moment of cutting stop in a collision. The pillow also has small ventilation holes that are used for relatively slow gauze boom after the passenger strike on it.
Frontal airbags should not be folded with lateral impact, hit in the back of the car or coup. Due to the fact that airbags only work and then fade quickly, they are useless with a subsequent collision. Safety belts help reduce the risk of gravity injuries in many cases. They contribute to the correct location of the passenger in the chair to maximize the airbag efficiency, as well as protect the fastened passengers in the first and subsequent collisions. Thus, it is vital to be fasted, even in machines equipped with airbags.
Although in the 60s and 70s, they were advertised as a potential belt replacement, at present, airbags are sold as an additional protection tool. Maximum effectively they work with seat belts. Car manufacturers revised their point of view about replacing the safety pillows so necessary belts.
- If there is at least one airbag next to the driver or passenger, the use of seat belts must be used. The pillow disclosure algorithm is designed as a driver (passenger) during their disclosure fastened with a belt. Therefore, the triggering of the pillows at the moment of uncontrolled sharp displacement of the human body during an accident can lead to unpredictable consequences. For example, in front of the front impact, an endless driver will receive a drop-down blow to the head in the head, according to an exceeding blow to the front panel (the opening rate of the pillow is over 300 km / h). In some modern cars (in what?) Disclosure of airbags during non-removable belts is blocked, as even modern pillows are effective only while using the knee or shoulder seat belts simultaneously.
- With respect to activation of airbags for unusted safety belts, there is discrepancies depending on the developed algorithm and car configuration. At the moment, you can split systems for 2 different versions. Automatic passenger passenger airbag shutdown and manual. The passenger airbag shutdown is provided by manufacturers for cases of the need to install a children's chair to the front vessel. In the case of an automatic system, the passenger airbag disconnection controls the control unit according to the algorithm in the program, deactivates the inclusion of the passenger airbag, based on the additionally installed device (weight sensor). Conditions from different manufacturers may differ. The basic principle of action is to measure weight (load) on the front passenger seat pillow. For example, if the sensor registers the weight of less than 25 kg on the seat - the system determines the seat as empty or seat with a children's chair installed on it. In this case, the airbag is not activated on the trigger when a collision. If the weight sensor on the seat cushion registers the presence of a load over 25 kg - the system determines this seat as an adult man and includes a pillow in a collision, if the collision has been sufficient force to activate pillows in general.
- Manual control of the need to activate the passenger airbag occurs exclusively at the initiation of a person (owner, driver or other person), by transferring the passenger airbag deactivation present in position = off (Off). In this case, the system will unconditionally turn off the passenger airbag and it is not activated when the conditions necessary to activate the conditions (the collision of sufficient force at which the security system is provided)
- It is necessary to be at a distance of about 25 cm from the airbag. The distance is measured from the center of the steering wheel to the sternum. Too small distance is dangerous and may lead serious injuries.
- The pillow can seriously injure or kill the wrong child who sits too close to her or was thrown forward in emergency braking. Children under 7 years old should ride fixed in the correctly installed, appropriate age automobile chair in the backseat.
- Smoking tube should be avoided when driving. If the pillow is revealed and hit the tube when that is in the mouth, it can lead to a fatal ending even with a slight impact.
Airbag opening is a very fast deployment of a large item. While airbags can protect passengers with proper conditions, in other situations they can cause injuries or even death.
The new generation airbags are open with less energy, but despite this, passengers should be at least 25 centimeters from them to avoid the applied of the wounds directly the airbag in the event of a collision.
In 1990, the first fatal exodus was registered related to the use of airbag. The peak of such cases emerged for 1997, when 53 such incidents were noted in the USA. In 1994, TRW, specializing in the release of automotive security, presented the first gas-filled pillow with special sensors and soon, capable of opening with a smaller power of airbag, were widespread. In 2005, airbags consisting of several separate segments that are filled depending on the situation appeared in passenger cars. By the time, the number of deaths due to wine airbags decreased, this year 2 deaths were noted among children, there are no victims among adults. However, injuries related to the opening of pillows remain very common.
According to the National Road Safety Authority (NHTSA), more than 50,000 people died in vehicles equipped with airbags. [five] . Most of them would die even if their cars did not have these means of protection, although it is impossible to find out the exact amount of died directly from the pillows. The assumption of NHTSA and other organizations is that it makes sense to consider only those cases when it is reliably known that the cause of death served as a airbag, and not those in which she could only be a reason, otherwise illogical as an assertion that every died in the car , equipped with a safety pillow, was killed by her. A reliable answer can only be given if there are the most detailed information about each case, the receipt of which is not possible.
Ironically, widespread use of airbags made the work of salvation services, firefighters and police are much more dangerous. Pillows that were not powered during a collision can work after a while, applying or leading to the death of rescuers inside the car. In addition, the use of side airbags reduced the number of places in which rescuers can use hydraulic scissors or other cutting tools for safe roof removal or car doors. Each rescuer must be properly instructed, how to properly deactivate airbags and avoid potential threats. A good precautionary measure is to disable the car battery. However, today most of the system diagnostic diagnostic blocks have devices that contain enough electrical energy to bring safety airbags in cases where the main rechargeable battery is contacted during a collision.
In Europe, the number of people who do not use seat belts are very little compared to the situation in the United States, in addition, the average european is less than an American. As a direct result of these two factors, European airbags are revealed at a lower rate (approximately 200 km / h) than their American analogs (approximately 300 km / h), and thus constitute a smaller threat to the life and health of passengers.
Also in the early systems there was a risk of obtaining a heavy barotrauma due to the actual explosive opening of pillows in a limited volume of the cabin. To combat pressure increase, the cabin will automatically be unloaded simultaneously with the pillow response, knocking out or instantly lowering the glass.
Honda has developed a simple variant of the phased control of the pillow opening. The shape of the pillow on the steps after the sinking explosion is set to plowing the spiral seams,  Similar to the insured ribbons of climbers.
The airbag system includes three main components:
- directly the airbag modules themselves;
- shock definition sensors;
- electronic control unit;
- Passenger airbag deactivation for the installation of a children's chair (optional).
The module of each airbag contains a filling unit in itself (usually a special pyropathron - filler (inflator), consisting of a steel case, the initiator - smelled (initiator), gas-generating content consisting of azide sodium and potassium nitrate, when combustion is highlighted by a large volume. Gas - nitrogen, and a light nylon pillow with calibrated holes. The driver's airbag module is located in the center of the steering wheel, and the passenger in the dashboard. Fully filled with gas, the driver's pillow has about the diameter of a large inflatable beach ball. Passenger can be in two or three The times is greater, since the distance between the passenger seated in front and the dashboard is much more than the distance between the driver and the wheel. When calculating the speed and need of filling, the size (volume) of the pillow bag is calculated in liters. The average volume of the driver's airbag is about 15 liters. . Pillow instantly fills gas m from the successful pyropatron, then it is blown away at a given pace through the calibrated, carefully calculated by the opening cross section, so that after the blow it was not clamped in the cabin and could free themselves. Filled combustion products from the trigger, the pillow will be warm or a little hot.
Some cars starting from the end of the 90s of the 20th century began to be equipped with, in addition to pillows, also a tightening system (emergency tensioner) seat belt. When determining the impact emblem and issuing a signal to activate airbags for several milliseconds before the start of the airbag signal response signal, the belt tensioner activator is issued. It is designed in such a way that in order to pull the housing of the person sitting on the seat in advance to the back to provide the volume of space before the human head for a safer disclosure and filling of the airbag bag. It should be borne in mind that seat belts with the emergency tension system are disposable, not repaired products, and if they are triggered or any malfunction is subject to replacement.
Front shock sensors are located in front of the car and / or cabin, and / or in the control unit itself. Cars can be equipped with one or more sensors, which are activated under the influence of forces (overload in G) arising from the front / side or totality of the vectors of the impact direction. Sensors measure the degree and speed of deceleration according to the specified program algorithm in the control unit. That is why the slowdown of the car, in which the sensors activate the pillows varies depending on the nature of the collision. Airbags should not be triggered with sudden braking or when driving on uneven surfaces. In fact, the maximum deceleration level during emergency braking is far from the level sufficient to bring safety airbags, it is due to the calculation algorithm. Each manufacturer of the airbag management system develops its own algorithm and software, which is the company's intellectual property and, possibly patented.
If there is a side airbag in the cabin in the cabin, the side impact sensors are additionally installed, and the ECU is more complicated by the number of electronic components and the software part contains a part that is responsible for control and activation of additional airbags. The block one, and the program in the block is both from two directed in different directions of blocks enclosed in one body of the block itself and the processor.
Side airbags work on the same principle as the front, but they are activated by the unit only with lateral impact or with a set of areas of overload vectors registered by the sensors.
The electronic control unit monitors the serviceability of airbags. When the ignition is turned on, a short-term verification of the integrity of external executive (initiators) and measuring (sensors) of devices is made. Also, the system, depending on the configuration, can conduct communication checks with other devices in the car and directly or indirectly involved in ensuring security. Checking the performance directly by the pyropatrons is carried out by checking the analog path of resistance on the lines of pyrcolon conclusions. Thus, no electric charges are submitted to the pyropathrius when checking any electrical charges, and it cannot lead to an unplanned initiatory response, but reliably determines the function of the chains. If the block detects a malfunction, the lamp will light up, the warning driver about the need to deliver the car to the authorized service center for diagnosing the airbag system (independently intervene in the operation of the system is urgently not recommended due to the presence of pyrotechnic elements in the design). Most control units have a small accumulated electric capacity in their scheme (capacitor), which is sufficient to activate the pillows with a sharp and complete de-energization of the car's on-board network, in case of damage to the power supply line in the car's wiring damage during collision. Example: with a sharp blow to the side of a large force, a lead battery, having a large mass, in some cases simply crashes out of the car, breaking the powerful wires even attached to it. It is for such or similar cases (refreshing the braids of the wires during a strike) in the block there is an additional capacity for short-term storage of energy charge. The capacity is discharged when de-energizing the control unit within a few minutes. In manuals for the repair of cars manufactured by car manufacturers for authorized centers, it is always written about this. Before starting work in the repair car related to the security system itself or indirectly affect any system elements, you need to de-energize the car for a few minutes, turning off the battery and other power sources connected to the car during repair (for example - Charger ).
The control blocks can be divided into modern and outdated. The first design structures were an electronic filling and a mechanical sensor element. The variations of the mechanical type sensor designs on the action were based on moving inside the sensor of a certain item with a certain mass. In the case of a certain slowdown, it moves in the sensor housing and affects the contacts of the airbag activation circuit. Roughly speaking, the principle of a pendulum shifting in the inertia.
Blocks are modern such a pendulum. Technologies in electronics since then stepped far in front. Now control blocks measure slowdown and acceleration by another. They are equipped with electronic accelerometers. Accelerometers can be installed both in the control unit itself, and can be made on different car body points and are located in those places where their installation is able to give the best accuracy of measuring acceleration, slowing down and rotating the body around its axis. Modern sensors have several vectors (measuring axes) x, y, z, which, in turn, allows you to use sensors in different appointments for measurements.
Modern car, depending on the plan of engineers, can be equipped with a block containing one or more accelerometers. In other cases, the car safety system can be designed with a control unit that does not contain accelerometers, and they can be made on the car body or accelerometers may be present both in the block and on the body. The larger the sensors containing accelerometers, the more precisely the measurement of the position of the vehicle in the space and its movement speed along the X, Y, Z axes. (X = up-down, y = back and forth, z = right-left) Zero with a sign of +/- displacement for one or another axis registers the sensor at a speed = S.
The program in the security control unit with ideal accuracy can determine the condition of the car. Regarding the state, a decision is made to activate airbags. Modern security control units containing several accelerometers are included in the ESP system - precisely due to the fact that accelerometers accurately determine the position and speed of the car.
Almost all modern cars have a manual ON / OFF switch to disconnect the front passenger airbag installed at the factory (if provided by the package). Sometimes it is an additional feature. For example, Ford Fiesta. In a simple configuration, it does not have a switch, but has a wiring on the braid near the glove box under the skin of the torpedo connector for the additional installation of this switch. All other elements of control and performance of the security system are initially configured as present or missing in the system at a system or car manufacturer. In some cases, the ability to enable or disable the elements installed into the system is provided through the configuration programming through a diagnostic session with specialized or multimarocre scanners. Switches for disconnecting the passenger airbag may be (if provided) are installed by qualified service personnel upon request of the vehicle owner, if it does not contradict the stated car manufacturer's policy or the system and it meets certain government criteria and has permission.
Initially, most cars were completed only by one driver's airbag (DAB) installed in the steering wheel and the protective driver (which is more likely to get injuries). During the 90s, the front passenger cushions (PAB), and then separate side pillows (SAB), placed between passengers and the door, became common practice. Now you can find enough inexpensive family cars equipped with 8-pillows.
The pillow may seriously injure or even kill an unused child who sits too close to her or was thrown forward in emergency braking. According to experts for the safety of the child, the following conditions are needed:
- Children should be transported in the correctly installed and appropriate age automatic chair in the back seat. Carefully learn the appropriate section in the instructions for the car.
- Babies transported in an rear armchair (under one year old and weighing less than 10 kg) should not be on the front passenger seat when the security pillow is enabled.
- If the child older than one year is forced to go on the front seat, equipped with a passenger seat pillow, then he or she should sit in a children's chair oriented towards movement, or fastened using a knee or shoulder strap, and the seat must be pulled back as far as possible. 
Pedestrian airbags [edit | Code ]
Experienced samples of airbags located outside the car are being developed, in front of the windshield.
Such pillows are open from the sign of the front bumper sensor and prevent the head of a pedestrian head about the windshield (about 80% of collision deaths). 
The first such technology received the car "Volvo V40". The airbag is part of the Pedestrian Detection system ("Pedestrian Detection") capable of detecting a pedestrian in front of the machine or about it. "Pedestrian Detection" consists of a sensor radiator located in the lattice, the camera located on the windshield behind the cabin mirror of the rear view, and the computer that analyzes the data obtained. The main task is to avoid a collision with a pedestrian.
If the collision happened, the "Pedestrian Detection" system works as follows. [nine] : The sensor fixes physical contact with a pedestrian, the upper end of the hood, which is closer to the windshield, rises and at the same time fits the airbag that closes about a third of the windshield and the front rack.
Jacket with air cushion for motorcyclists [edit | Code ]
The new spaces in the safety of motorcycles opened the airbag integration system into the jacket to which the activator cord and the cartridge filled with the compressed gas belongs. When landing on a motorcycle, it is necessary to fasten with the help of a flexible rope to the motorcycle housing. The second end of the rope is connected to the shock design of the cartridge filled with carbon dioxide and in the jacket. When falling and shuffles, a motorcyclist, which was removed from the motorcycle, pulls the fastener cable and this very discovers the cartridge, which leads to an automatic inflating air system of the jacket for 0.1 - 0.3 seconds. The airbag jacket significantly reduces the strength of blows on the body and effectively protects the vital internal organs of the motorcyclist, as well as the spine, neck, ribs, clavicle, cork.
Jacket with airbags for motorcyclists and riders - the Hungarian invention, which invented Straub Tamas in 1976. [ten]
Airbags for cyclists [edit | Code ]
Designers Anna Hawpte (Terese Alstin) from Sweden developed a prototype airbag for motorcyclists and cyclists called Hövding, which is inflated in the event of a fall and protects his head and neck from serious injury. The pillow is inside the waterproof tissue cover and is attached to the pilot neck. At the time of the fall, the pillow is revealed in 0.1 seconds, providing protection is not worse than an ordinary motorcycle helmet. Remove SRS errors on Mercedes W220 Installing an emulator!