How is the car anti-lock braking system ABS? Exploring ABS: Last Chance What an Abs System Looks Like

In modern cars, not only passive, but also active safety systems are widely used, which help the driver to get out of a critical situation without allowing an accident. One of the most widespread and effective systems is anti-lock braking system (ABS), which prevents the wheels from locking and slipping when braking. Read about this system, its structure, operation and features in this article.

Purpose of the anti-lock braking system

It would seem that it could be easier than braking the car - it is enough to stop the rotation of the wheels and the car will stop. However, here everything is not as straightforward and simple as it seems, and sometimes simple braking can lead to completely unexpected results. Surely, every driver found himself in a situation when, when the brake was pressed sharply, the car was in no hurry to stop, on the contrary - the locked wheels simply slid along the road, increasing the braking distance, the car was skidding, and the likelihood of an accident greatly increased. What is the reason?

And the reason is simple and lies in the blocking of the wheels when the brake pedal is pressed firmly. A rotating wheel has a constant area of contact with the road surface, and, despite the rotation of the wheel, at each moment of time in this contact area there is a static friction force - it is this that ensures good grip of the wheel with the road and controllability of the car.

But when you press the pedal firmly, the brake pads completely block the wheels, and they go skidding, that is, they just slide along the road. In this case, too, the force of static friction in the contact patch is replaced by the force of sliding friction, and this radically changes the matter. The effective sliding friction force is less than the static friction force, which means that the wheel loses contact with the road, the car slides and becomes practically uncontrollable. Any lateral force (and this can be a roughness of the road, uneven rotation of the driving wheels, etc.) that occurs when sliding makes the car deviate from a straight path - this is how skids, side sliding and, as a result, emergencies occur.

Uncontrolled slipping can be prevented by proper braking, which does not cause wheel blocking. Experienced drivers use a special braking technique for this - they quickly and quickly press and release the brake pedal, blocking the wheels for a short time and then releasing them. With such braking, the wheels are not completely blocked, do not skid, and the car does not slip into a skid.

In modern cars, the problem of wheel locking during braking is solved by a special active safety system - the anti-lock braking system (ABS). This system automatically prevents the wheels from locking, providing the most effective braking, keeping the vehicle under control and preventing an emergency. Also, the ABS provides the ability to maneuver the car during emergency braking, which makes a great contribution to improving the safety of the car.

Interestingly, the first attempts to create such a system were made by the well-known company Bosch (which generally succeeded in creating car safety systems) in the 1930s, but the technologies of that time did not allow creating a normally working system. In the 1960s, attention was again drawn to this topic, which was associated with the development of electronics, but the first successes were achieved a decade later - already in the 1970s, ABS was offered as an option in executive cars, and in 1978 the system became standard. for some BMW and Mercedes-Benz models. And relatively recently - in 2004 - a legislative decision was made on the mandatory installation of anti-lock braking systems on all new cars sold in the European Union.

In conclusion, it should be noted that the abbreviation ABS is of German origin, it means Antiblockiersystem. However, it is equally well suited both under the English name of the system (Antilock Brake System) and under the Russian name (ABS - anti-lock braking system).

hydraulic pump
pressure accumulator
wheel gauges
solenoid valve block

ABS device

It has a fairly simple device, it includes several basic elements:

Wheel speed sensors;
- Electronic control unit;
- Actuators - ABS hydromodulators.

Wheel rotation sensors. These sensors measure the angular speed of rotation of the wheels, and based on the information received, the electronic control unit decides to turn on the ABS. Today, the most commonly used sensors are based on the Hall effect, and simple inductive sensors are also widely used.

Electronic control unit. This is a computer, the "brain" of the entire system, it processes information from sensors, and when a critical situation arises, it turns on the executive devices. Today, a single electronic unit is often used to control the ABS, traction control system, directional stability system and other active safety systems.

Executive devices. Typically, the ABS includes a hydraulic block in which various components are combined - valves, a pump, pressure accumulators, etc. This unit is often called a hydromodulator, as it creates a variable pressure in the system with a frequency of 15-20 times per second.

It is interesting to note that the ABS can be easily integrated even in a non-new car - modern anti-lock braking systems are a compact and lightweight set of components that can be easily connected to the standard brake system. The most advanced ABS samples from Bosch weigh no more than a kilogram and can be installed on almost any vehicle, including trucks.

How the ABS works

Anti-lock braking systems can be divided into three stages:

Emergence of a critical situation (risk of wheel blocking) - the electronic unit decides to turn on the hydraulic unit;
- Operation of the hydraulic unit - periodic increase and decrease of pressure in the brake system;
- Turn off the system when unlocking the wheel.

It should be noted here that modern ABS work on the basis of algorithms embedded in the electronic control unit, and the system is triggered not at the moment the wheels are locked, but in advance. Of course, the simplest thing would be to make a system in which sensors would track the speed of the wheels, and when the wheel stopped, they would start the mechanism for unlocking it. However, in reality, such a system is ineffective, since it turns on when the wheel is already blocked, which means that it does not solve the problem.

The ABS work algorithms are based on measuring the speed and angular acceleration of the wheels, and act "ahead of time" - the driver sharply pressed the gas, and the system already "knows" that at the current speed this will most likely lead to wheel blocking, and begins to act. Actually, the development of modern anti-lock braking systems is aimed at increasing the efficiency of its work at all modes and speeds.

The work of the ABS is as follows. When a critical situation arises (the wheel speed drops sharply), the electronic unit turns on the hydromodulator, which first stabilizes the pressure in the wheel brake cylinder (closes the inlet and outlet valves), and then provides the brake fluid pressure pulsation. When the pressure drops (the exhaust valve opens, and the brake fluid is supplied to the pressure accumulator), the wheel stops blocking and turns at a certain angle; when the pressure rises (the brake fluid is pumped into the cylinder through the intake valve), the wheel is braked. As a result, the wheel does not brake completely, but turns slowly, being on the verge of blocking.

The pressure pulsation of the brake fluid occurs at a frequency of 15-20 times per second, and this is clearly felt by the foot - the brake pedal also begins to pulsate when the ABS is turned on. When the speed is sufficiently reduced to eliminate the risk of blockage, the system is deactivated. System operation is usually indicated by a corresponding indicator on the car dashboard.

We said above that when the ABS is triggered, the wheels are on the verge of blocking, but where does this edge lie? For definition, such a concept as the degree of wheel braking is often used, which varies from 0% (the wheel is completely unbraked) to 100% (the wheel is locked). The most effective braking is performed when the wheel braking rate is 15-20% - this is exactly the extent to which the anti-lock braking system brakes the wheels.

In general, the ABS operation mimics the braking style used by experienced drivers for a long time to prevent skidding - harsh and frequent pressing and releasing of the brake pedal. Only the electronic system works more reliably, better and more efficiently than the most experienced chauffeur.

Types of anti-lock braking systems

Today there are four main types of ABS, which differ in the number of control channels. There can be from one to four channels, and each type of system has a corresponding name.

Single-channel ABS. The system controls all wheels at once simultaneously, in such a system there is one inlet and one outlet valve, and the fluid pressure changes immediately in the entire brake system. Typically, a single-channel ABS controls only the wheels of the drive axle and uses one sensor. Such a system is ineffective and can often fail.

Two-channel ABS. In such a system, the wheels of each side are separately controlled. ABS of this type works well, since very often the car pulls to the side in emergency situations, and at the moment the ABS is activated, the wheels of the right and left sides are on surfaces with different characteristics, therefore, for their effective braking, it is necessary to use different ABS algorithms.

Three-channel ABS. In this system, the rear axle wheels are steered by one channel (as in the single-channel system), and the front wheels are individually steered.

Four-channel ABS. This is the most advanced ABS, it has a sensor and valves on each wheel, which provides maximum control and the ability to control each wheel independently of the others.

Different types of ABS do not work in the same way on different types of vehicles, so all of them today have received one or another distribution. The price of systems also plays an important role - a four-channel system is more expensive than others, therefore it is installed on expensive cars, three-channel systems are widely used on passenger cars, two-channel systems - on small trucks, etc.

Started in the late 70s. It was a revolutionary new braking system that was designed to improve the safety of motorists in critical situations associated with emergency braking.

From now on, in any driving situation in the most critical conditions (wet or slippery asphalt), the wheels of the car were not blocked even during emergency braking.

The ABS system consists of:

Hydraulic block;
Control unit;
Wheel brakes;
Sensor speed sensors.

The brain of the ABS system, as you understand, is the control unit, it receives signals that come from sensor sensors in the form of the number of wheel revolutions. After that, the received data is processed and, based on them, the block concludes whether the wheel is sliding or not, slowing down or accelerating. The decision is made with lightning speed, after which a signal is sent in the form of a command to the magnetic valves of the hydraulic unit, which actually carry out these commands.

The hydraulic block is located between the caliper brake cylinders and the brake master cylinder (GTZ). The pressure that comes from the GTZ in the brake cylinders of the calipers is converted into a pushing force, due to which the brake pads are pressed against the brake discs. Regardless of how hard the driver presses on the brake pedal and in what situation, the pressure in the brake system will always be optimal.

The beauty of the ABS system is that it is able to analyze the condition of each wheel and individually select the optimal pressure to prevent wheel blocking. Braking to a standstill is controlled by ABS using the pressure in the brake drive system, so it is directed directly to the braking effect.

The pressure is regulated according to the following principle: the speed sensors count the revolutions of not only the front wheels, but also the rear axle differential (in rear and all-wheel drive models) and the rear wheels. The data is needed by the control unit in order to calculate the peripheral speed of the wheels. After completing the counting and determining that the wheel or wheels are locked or are on the verge of locking, a command is sent to the solenoid valves and the return pump of the corresponding wheel (s). Each of the calipers is pressurized to provide the wheel with maximum braking performance and no blocking effect. equipped with only one sensor of the number of revolutions on the differential of the rear axle, the possibility of locking the wheels is determined by the one most located to this wheel, after which the braking force for the entire row is determined. As a result, the wheel with the best adhesion coefficient receives slightly less braking, which cannot but increase the braking distance, but at the same time much better vehicle handling is maintained compared to a vehicle without ABS.

The device that controls the solenoid valves is capable of operating in three different positions:

The first is to create pressure ... The GTZ is connected to the brake cylinder, which means that the exhaust valve is closed, and the intake valve is open, therefore the pressure can easily build up.
The second is to hold pressure ... Interruption of communication between the GTZ and the brake caliper cylinder is a condition when the pressure in the brake drive system is constant. That is, a signal is sent to the intake valve, as a result of which the valve remains closed, thereby preventing an increase in pressure.
The third is pressure reduction ... The pressure in the brake system is reduced because the exhaust valve is signaled to release pressure and then opens. At the same time, the pressure decreases due to the activation of the return pump, as a result of which the inlet valve closes.

Thanks to three different working positions, the ABS system is able to increase or decrease the pressure in the braking system in a "stepwise" manner, by stepping action on the solenoid valves. In a working system, these positions are capable of changing from 4 to 10 times per second, this largely depends on the type of road surface.

If a malfunction is detected in the system, it is deactivated at the same minute, at the same time it continues to work in normal mode, but without the participation of ABS. The braking itself is significantly different and has a significantly lower efficiency. The driver will recognize that the ABS system is out of order by the emergency indicator located on the dashboard. The method of finding and determining the malfunction may differ, here the year of manufacture and the type of ABS play a greater role.

Diagnostics of malfunctions of the ABS system

Circuit breakers

Visual inspection of the fuse box makes it possible to rule out the first possible cause of the malfunction. Before disassembling all other components of the ABS system.
Inspect all connections and connectors for scuffs or poor contact. Such seemingly insignificant malfunctions can damage the entire system or cause it to malfunction. Make sure. that there are no traces of mech on the parts (speed sensors, sensor wheels). damage and check if everything is in order with the mass.

Unfortunately, it often happens that the ABS system fails due to incorrect tire selection.

To eliminate the likelihood of "cheating" sensors, check

The performance of the brake system, preferably on the bench, also check its tightness.

If, after carrying out the above checks, the malfunction could not be identified, you must continue the search.

Experience shows that most of the ABS faults are associated with a broken connector connection or wire breakage, in order to confirm or deny these faults, it is enough to have a tester or an oscilloscope.

Before starting testing, make sure that it is completely so that during measurements you can track possible voltage surges on connectors or conductors.

Failures in the operation of ABS sometimes arise due to malfunction of the speed sensor sensors, which will be discussed below.

The speed sensors are located above the impulse rotor connected to the drive shaft or hub. A winding is located around the pole core, it is connected to a permanent magnet, due to which the magnetic field easily penetrates the inductor. The change in the magnetic flux through the winding and the core occurs due to the rotation of the impulse rotor and the associated change of teeth and interdental cavities. The magnetic field is constantly changing, inducing an alternating voltage in the winding, which can be measured. The amplitude and frequency of this voltage is equal to the number of revolutions of the wheel.

To check the speed sensor you need to measure the resistance and voltage in the system. The resistance should vary from 800 Ohm to 1200 Ohm (take the nameplate values into account). If the resistance is 0 Ohm, we can safely talk about a short circuit, but if the value is equal to infinity, this is an open circuit.

In the event of a sensor malfunction, it must be replaced, the main selection criteria in this regard should be quality, so take this procedure seriously so that the money is not wasted. Remember that your safety and the safety of other road users depend on the serviceability and efficiency of the ABS and the entire braking system as a whole.

How hard it is for a beginner to drive a car for the first time! So it seems that everyone is only dreaming of hooking your car, and you yourself are afraid of hurting someone else.

Himself all wet, sweat pours into my eyes, my legs are trembling, and my right leg is ready to press the brake pedal all the way, even with a hint of any danger. But this is wrong. Not to mention everything else, it is necessary to slow down not all the way, but wisely. This will help, if of course it works out, the anti-lock braking system.

What is braking, and how to brake

Only at first glance it seems that the most important thing is not to be late to press the brake, then the car will stop. In fact, everything is much more complicated.

When braking, several forces act on the car, so it is sometimes difficult for even an experienced driver to cope with this process, especially on slippery or wet roads.

Here is the simplest example - the car is moving at speed, the driver noticed a danger, sharply applied the brake, and the car jumped out into the oncoming lane. And if you're lucky, then on the side of the road or on a pole.

What is the reason for this behavior of the machine? In the wrong braking. How does it happen in a car? When the brake pedal is depressed, both the rear and front wheels begin to decelerate.

If at the same time at least one wheel is blocked (it stops spinning and decelerating, but begins to simply slide on the road surface), then the braking distance increases, and the possibility of the car skidding towards the blocked wheel increases significantly.

To avoid such a situation, to improve the braking efficiency, especially in a critical situation and on slippery roads, it is necessary to brake intermittently. Step on the pedal, and when the wheels on the car are almost locked, release the brake pedal, and then repeat this a few more times until the car stops.

In fact, instead of pressing and holding the pedal in this position, you have to press it repeatedly, press and release, press and release. In this way, it is possible to keep the car on the verge of locking the wheels.

This braking system allows you to stop the car much more efficiently, especially on slippery and icy roads.

Of course, it is very scary when, for example, the tailgate of a truck starts approaching you, and you have to release the brake pedal. If you can't handle it, don't drive or buy a car with ABS.

What is ABS

This abbreviation is on everyone's lips, an abbreviation translated from English as anti-lock braking system.

In fact, in its simplest form, it is an electromechanical system that imitates the actions of an experienced driver and provides effective braking on slippery roads.

If it is installed on a car, it makes life much easier for novice drivers. Although you should not place too high hopes on it - ABS only helps the driver to drive the car, and not drives it itself.

So, the driver must know his car, its behavior in different situations and on different road surfaces, including the behavior taking into account the operation of additional systems.

A little historical background

Above, we have already considered a possible situation when the driver cannot cope with the car for purely psychological reasons. To eliminate such a scenario when driving a car, an anti-lock braking system was developed.

Its first samples appeared in the last century, in the seventies, however, due to the lack of a suitable and reliable element base, they did not receive wide development.

With the advent of digital microcircuits and affordable microprocessors and microcontrollers, the situation changed dramatically. Thanks to these elements, the ABS system appeared on the car.

It happened in 1978, and the first car with such a system was one of the Mercedes.

About the structure and operation of ABS

What is ABS, you can understand from the figure below. The entire system consists of several independent units:

control unit (Control Module);
wheel speed sensors (Wheel Sensors);
hydraulic unit (Modulator Unit).

If the purpose of the control unit as well as the speed sensors is intuitive, the functions and composition of the hydraulic unit need some explanation.

Its elements are:

exhaust and intake solenoid valves;
pump with electric motor for brake fluid return;
pressure accumulators;
damping chambers.

Each wheel has its own exhaust and intake valves.

Built-in speed sensors monitor the wheel speed. The control is carried out using the effect of electromagnetic induction.

It happens in the following way - when the wheel rotates around the sensor, there are teeth located on a special rotor rotating at the same frequency. Passing the speed sensor, the teeth cause there the appearance of an emf proportional to the speed of the wheel rotation, due to which its current state can be estimated.

How ABS works

To understand how anti-lock braking system works, it is necessary to consider the possible options for its operation.

Basically, there are three phases of ABS operation:

pressure relief in the working cylinder;
retention of pressure in the working cylinder;
increase in pressure.

To begin with, it should be noted that the hydraulic unit on the car is installed on the highway behind the main brake cylinder, and the electromagnetic valves control the flow of brake fluid into the brake cylinder.

Work and control is carried out by determining the wheel speed. After the start of braking (pressing the brake pedal), the anti-lock braking system determines the frequency of its rotation. If the wheel stops rotating and starts to slide, this is indicated by the speed sensor.

The control unit then opens the outlet valve and stops the supply of brake fluid to the brake cylinder. When the wheel starts to rotate and its speed exceeds the set limit, the anti-lock braking system closes the exhaust and opens the inlet valve.

As you continue to brake, all steps are repeated until the vehicle comes to a stop.

Types of ABS

All of the above applies to the option if the car is equipped with the latest generation anti-lock braking system, or the so-called four-channel ABS.

In this case, the blocking of each wheel is monitored, and for each of them, the electronics takes corrective action. Such a system is the most expensive and complex.

However, there are other types as well.

Thus, a single-channel anti-lock braking system controls the braking force for the entire vehicle at the same time. This type of ABS is much simpler and cheaper, but it works well when the grip of all wheels is the same.

Dual channel anti-lock braking system controls braking force along one bead.

ABS is not omnipotent

The presence and operation of the ABS system on the car greatly simplifies the braking process and makes it more effective, especially for novice drivers. But at the same time, it has certain disadvantages, and they must be taken into account when driving a car.

Here, by the way, it should be noted that when the anti-lock braking system works, its operation is felt like vibration on the brake pedal.

Of those cases when flaws in the operation of the system become obvious, the following can be noted.

The performance of ABS depends on the quality of the road surface. On an uneven road, bumps, paving stones near the car, the braking distance with such a system increases somewhat. The fact is that when the wheel bounces on bumps and is in flight, i.e. there is no grip on the road, ABS gives the command to release the braking. But at the moment when the wheel starts to contact the surface again, the set braking force turns out to be non-optimal and the braking distance increases. This effect can be countered by reducing the speed of movement and increasing the distance.
Increased stopping distance on mixed surfaces - in cases where sections alternate, for example, asphalt - water - asphalt - snow - ice. In this case, the following happens - the system releases the brakes on a slippery area, when the wheel hits the normal surface, the steady braking force is insufficient, as a result of which the braking distance increases.
Braking on a loose, loose surface (sand, loose snow). In this case, the braking distance with ABS is increased. The fact is that if the car skids on the sand, then a roller of sand appears in front of the wheel (plow effect), and it will be much more efficient to stop the car. In such a situation, skid braking will be better.
The system stops working when stopped. At low driving speeds, the ABS is deactivated and does not work. This can be very frustrating when driving on a slippery slope. We must remember this and be ready for timely action, for example, use the hand brake to stop.

Anti-lock braking system allows you to brake more effectively in difficult driving situations, avoiding skidding and maintaining control of the vehicle. This will result in a significantly shorter braking distance and significantly increased safety.

However, such a braking system has some features, and you must be prepared for their manifestation when driving.

Anti-lock braking system ABS (ABS) is a system that prevents the wheels from locking completely during emergency braking. This solution is one of the first electronic active safety systems, which began to be widely installed on cars.

Today, such a system is an integral part of almost any modern car, even in the budget segment. Also, in developed countries, the mandatory presence of ABS in a car is enshrined at the legislative level.

At the same time, many drivers know that the car has this system, but they do not fully understand what ABS is and how this solution works. In this article, we will look at how ABS works, what it is, as well as what functions such a system performs and why it is important to monitor the health of the ABS in the car.

Read in this article

ABS system: purpose and features

Before considering ABS, what it is and how the system works, you need to understand the main purpose and functions. Let's begin with that . Also, when you press the brake pedal sharply, you can feel the characteristic vibration of the pedal. All this indicates the presence and operability of the specified system on the machine.

So, ABS or anti-lock braking system does not allow the wheels to lock during active braking. Such a system avoids a complete loss of control in the event of blocking of the steered wheels. More precisely, ABS is a system that allows you to control the pressure in the brake lines.

To begin with, a car without ABS, with the brake pedal pressed and on fully locked wheels, simply slides without responding to the steering wheel. To be able to drive the machine, release the brake pedal and partially unlock the wheels, allowing them to turn.

Race car drivers and professional drivers are well aware of this feature, practicing on a car without ABS the so-called reception of impulse (step) braking. The whole technique boils down to the fact that the driver quickly presses and then slightly releases the brake pedal, thereby blocking the wheels for braking, however, not allowing complete blocking so that there is no loss of control.

It goes without saying that an ordinary driver, and not an experienced professional, during emergency braking experiences instant fright and presses the brake hard. In this case, a car without an ABS becomes simply uncontrollable, turning the steering wheel during braking does not allow changing the trajectory of the vehicle.

In such a situation, control over the car is lost, it is impossible to go around the obstacle, in any way change the trajectory of the car when braking, etc. Naturally, all these factors have long been the cause of numerous accidents with serious consequences.

The ABS system was called upon to solve the problem. In a nutshell, when the driver pushes the brakes hard, the system actually simulates the work of a professional racer, who very quickly applies and releases the brakes. At the same time, electronics copes with the task much faster and more efficiently compared to humans.

The vibrations that are felt during the operation of the ABS on the brake pedal in the form of a "ratchet" are the very impulses-pressing. More specifically, as soon as the system senses that a wheel is locked, it reduces the brake line pressure on that wheel to allow it to spin.

Until the driver releases the brake pedal, the process of locking and unlocking the wheel occurs continuously several times per second until the driver stops pressing the pedal hard. The ABC system is configured so that ABS anti-lock is only triggered when braking is active, that is, when braking slightly, its operation is often not felt.

It should also be added that on a car with ABS, the car with emergency braking has an increased stopping distance compared to models without such a system in exactly the same conditions. In other words, it is a mistake to think that an anti-lock braking system is necessary to shorten the stopping distance. Its main task is to maintain controllability during braking, as well as to ensure uniform and, if possible, straight-line braking.

If we talk about stopping distance, everything will depend on the coverage. For example, if you brake sharply on dry asphalt, the ABS will shorten the braking distance, preventing the wheels from sliding. If you brake on loose surfaces, on snow or on ice, the wheels locked without ABS are buried and the braking distance is shorter.

However, even taking into account the increase in braking distance, it is the ABS that retains the ability to maneuver and control the car, which is often much more important.

ABS device and circuit

So, having figured out the purpose, you can move on to how the ABS system works, what it is in terms of design. So, the ABC system (as inexperienced motorists sometimes mistakenly prescribe the abbreviation on the forums), includes the following basic elements:

ABS unit;
set of ABS sensors;
pressure relief valves;
wiring;
pump;

To understand how ABC works and what it is, it is enough to imagine the entire system as a tool that controls the brake fluid pressure at each wheel. Otherwise, the ABS system detects which wheel is locked, then the valve opens and the brake fluid pressure drops.

After the valve closes and the pressure rises. If a pump is integrated into the ABS system, this solution allows you to quickly build up the required pressure. As a result, the combination of the ABS block + sensors on the wheels effectively cope with the task at hand.

We also note that the ABS systems differ in the number of sensors and valves in the hydraulic lines. Today, four-channel, as well as three-channel, two-channel and even single-channel systems can be distinguished. Depending on the number of channels, it is possible to more or less flexibly control the pressure in the brake system.

For example, if there are three channels, then the ABS works with two front wheels separately, while at the same time only one channel goes to the rear axle. Two channels are available for front and rear axle operation. Of course, modern systems are four-channel, that is, for each wheel separately. Other solutions are not used because they are outdated.

By the way, we also add that ABS sensors are also used in some control systems. It turns out that the ABS system has not only evolved, but also the individual capabilities of its constituent components have been expanded.

If in developed countries, cars without ABS are practically not found, then on the territory of the CIS many such cars travel on the roads (domestic auto industry, old foreign cars, some new super-budget models, etc.). Also, on many cars, this system simply does not work, and the owners are in no hurry to fix the malfunction.

In any case, understanding what the ABS is for, what it is and how it works, allows us to give several recommendations to drivers who do not have such a system. Of course, if ABS is a guarantee that the wheels will not lock, then the absence of such a system means the need for the driver to acquire certain emergency braking skills.

In other words, the operation of the ABS can be replaced by intermittent braking by depressing the pedal with frequent jerks. Of course, in an emergency it is difficult to apply such a technique, since the driver instinctively presses on the brake with all his might, without removing his leg.

If the situation is predictable, then this technique is similar to the operation of a single-channel ABS. Intermittent braking will allow you to brake with sufficient efficiency and at the same time maintain control during braking.

Let's summarize

Taking into account the above information, it becomes clear that in order to increase comfort and safety, equipping the car with an anti-lock system is mandatory. Having considered ABS, what it is and how it works, it can also be argued that it is a simple and at the same time important, and also very useful solution.

Even in spite of the statements of skeptics that the ABS increases the braking distance, such an assistant during extreme braking is simply indispensable, especially when it comes to ordinary drivers.

As a result, we note that understanding the principles of the ABS, what it is, as well as what kind of braking should be expected on a car with such a system, allows us to take into account in advance a slightly increased stopping distance on certain surfaces.

In turn, this additionally encourages drivers to keep their distance, as well as to avoid other difficult situations that may arise if some of the features of the anti-lock braking system are not separately taken into account.

Anti-lock braking system includes:

Speed sensors - mounted on wheels.
Control valves - pressure modulator elements located in the support.
The control unit coordinates the whole process: it is responsible for the operation of the valves, using the signal from the sensors.

The electronic control unit (ECU) ABS contains thousands of parameters that are tuned for a specific car brand.

While most ABS systems are supplied by companies such as Bosch, the software settings for braking on different surfaces and conditions will be different for different car brands.

Even if two different cars have identical ABS systems - they will be tuned very differently for a sports car versus an SUV.

How does ABS work?

When the driver depresses the brake pedal, it seals the hydraulic system, which causes the brake pads to compress against the discs. As a result, the car slows down.

If the ABS detects that the rotation speed of one wheel is decelerating more rapidly than the others (wheel lock sign). Possibly low friction of the wheel due to contact with a surface such as ice.

The ABS control module detects the start of a lock through a sensor in this wheel and reacts by gradually reducing the brake pressure by quickly opening the hydraulic pressure release valve.

ABS also has the ability to build up pressure back through the hydraulic motor. The system performs similar actions with the control of the car rather quickly, thereby shortening the braking distance.

This process is repeated, leading to a noticeable pulsation of the brake pedal. The wheels seem to grip and release in convulsive movements. The driver will definitely note the moment the anti-lock braking system is working, feeling such a pulsation under the foot.

There are single-channel, dual-channel, and multi-channel ABS. The first two systems are good when the grip of the wheels with the road surface is approximately the same.

In the case of a non-uniform road surface (ice, sand, puddles, roadside), an independent multi-channel ABS will be more reliable in use. A multichannel system is more expensive, but more efficient in operation.

Most modern vehicles use a four-channel ABS system, which provides greater safety in emergency braking situations.

How to use ABS correctly

ABS works best when the brake pedal is firmly applied. During ABS operation, some vibrations are felt, which are pressure release valves opening and closing, and a sign that the system is working properly. Do not release the pedal until you have stopped safely.

Braking with and without ABS

It is no secret that it is possible to slow down more quickly in a car without ABS. There is some truth to this, but in practice the benefits of ABS on a massive scale outweigh the slightly longer braking distances.

For road use ABS is a vital necessity as it avoids unexpected hazards.
The driver applies the brake hard on a slippery surface, then holds the brake pedal, and successfully avoids obstacles.

ABS prevents the wheels from jamming and allows for maneuvering during braking.
Without ABS, the driver applies the brakes and the wheels become jammed. Despite holding the brake, the vehicle continues to move forward due to loss of control.

With correct threshold braking, a vehicle equipped with ABS can decelerate faster.
Many competitive racers would say they prefer that their cars don't have a system. However, to get the maximum advantage, you need to practice the threshold braking method repeatedly.

Good test:

Find a test site and mark the cone that will act as a braking point.
Accelerate to 100-120 kilometers per hour and apply the brakes as hard as possible in a vehicle equipped with ABS
Repeat all too without ABS

Compare braking distances if available, mark them on the side of the track, then the braking threshold, with practice, improvement will appear.

And one more tip, if you have ABS, don't get into the habit of locking the wheels before entering a corner - this is not the fastest way to slow down and can upset the ABS system in the car.

Conclusion

Nowadays, cars with an electronic braking system acting independently on each of the wheels are becoming more common. In this case, the system has no effect on the brake pedal.

ABS works as a single algorithm for the braking system. Thanks to electronics, units and mechanisms began to work more reliably, and the transport itself became safer.

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