When the abs kicks in on the car. Installation diagrams abs. About the structure and operation of ABS

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

The purpose of the anti-lock braking system

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

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

But when you press the pedal hard, 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 slips and becomes almost uncontrollable. Any lateral force (and this can be road roughness, uneven rotation of the drive wheels, etc.) that occurs during sliding causes the car to deviate from a straight path - this is how drifts, side slip and, as a result, emergencies occur.

Uncontrolled slipping can be prevented by correct braking, which does not cause wheel locking. Experienced drivers use a special braking technique for this - they sharply and quickly press and release the brake pedal, blocking the wheels for a short time and immediately releasing them. With such braking, the wheels do not block completely, they do not go skidding, and the car does not break into a skid.

In modern cars, the problem of blocking the wheels during braking is solved by a special active safety system - anti-lock braking system (ABS). This system in automatic mode prevents the wheels from locking, providing the most effective braking, maintaining vehicle control, and preventing an emergency. Also, 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 all famous company Bosch (who generally excelled at building automotive security systems) in the 1930s, but the technology of the time did not allow for a properly working system. In the 1960s, attention was again paid to this topic, which was associated with the development of electronics, however, the first successes were achieved a decade later - already in the 1970s, ABS began to be offered as an option in executive cars, and since 1978 the system has become standard for some BMW and Mercedes-Benz models. And relatively recently - in 2004 - a legislative decision was made on the mandatory installation of an anti-lock braking system 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 equally suits both the English name of the system (Antilock Brake System) and the Russian one (ABS - anti-lock braking system).

1. hydraulic pump
2. pressure accumulator
3. wheel sensors
4. block of electromagnetic hydraulic valves

ABS device

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

Wheel speed sensors;
- Electronic control unit;
- Executive devices - ABS hydraulic modulators.

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

Electronic control unit. This is a computer, the "brain" of the entire system, it processes information from sensors, and in the event of a critical situation, it turns on the actuators. Today, a single electronic unit is often used to control the ABS, traction control system, exchange rate stability system and others. active systems security.

executive devices. Usually, the ABS includes a hydraulic unit, which combines various components - valves, a pump, pressure accumulators, etc. Often this block is called a hydraulic modulator, since 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 the most new car- modern anti-lock braking systems are a compact and lightweight set of components that can be easily connected to a 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 ABS works

The operation of the anti-lock braking system can be divided into three stages:

The occurrence of a critical situation (risk of blocking the wheels) - the electronic unit decides to turn on the hydraulic unit;
- The operation of the hydraulic unit - periodic increase and decrease in pressure in the brake system;
- Switching off the system when the wheel is unlocked.

It should be noted here that modern ABSs work on the basis of algorithms embedded in the electronic control unit, and the system is activated not at the moment the wheels lock, but in advance. Of course, the simplest would be to make a system in which sensors would track the speed of the wheels, and when the wheel stops, the mechanism would be triggered to unlock 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 operation algorithms are compiled on the basis of measuring the speed and angular acceleration of the wheels, and act "in advance" - the driver has sharply pressed the gas, and the system already "knows" that at the current speed this will most likely lead to blocking of the wheels, and begins to act. Actually, the development of modern anti-lock braking systems is aimed at improving the efficiency of its operation in all modes and speeds.

The operation of the ABS is as follows. In the event of a critical situation (the angular velocity of the wheel drops sharply), the electronic unit turns on the hydraulic modulator, which first stabilizes the pressure in the wheel brake cylinder (closes the inlet and outlet valves), and then provides pressure pulsation brake fluid. When the pressure drops (the exhaust valve opens and the brake fluid is supplied to the pressure accumulator), the wheel stops blocking and rotates at a certain angle, when the pressure rises (the brake fluid is injected into the cylinder through inlet valve) the wheel is braked. As a result, the wheel does not brake completely, but turns slowly, being on the verge of blocking.

The brake fluid pressure pulsation 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 and the risk of blockage is eliminated, the system is switched off. The operation of the system is usually displayed by the corresponding indicator on dashboard car.

We said above that the wheels are on the verge of blocking when the ABS is activated, but where does this line lie? The definition is often used such a thing as the degree of braking of the wheel, which varies from 0% (the wheel is fully disengaged) to 100% (the wheel is locked). The most effective braking is performed when the degree of wheel inhibition is at the level of 15-20% - it is to this extent that the anti-lock braking system slows down the wheels.

In general, the operation of ABS mimics the style of braking that has long been used by experienced drivers to prevent skidding - sharp and frequent pressing and releasing the brake pedal. Only the electronic system works more reliably, better and more efficiently than the most experienced driver.

Types of anti-lock systems

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

Single channel ABS. The system controls all the wheels at once at the same time, in such a system there is one inlet and outlet valve each, and the fluid pressure changes immediately in the entire brake system. Usually single-channel ABS controls only the wheels of the drive axle, and one sensor is used. Such a system is not efficient, and can often fail.

Dual channel ABS. In such a system, the wheels of each side are separately controlled. This type of ABS works well, since very often the car pulls over to the side of the road 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, so for their effective braking it is necessary to use different ABS algorithms.

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

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

Different types of ABS work differently on different types Vehicle, therefore all of them today have received this or that distribution. The price of systems also plays an important role - four-channel is more expensive than others, therefore it is installed on expensive cars, three-channel systems are widely used in cars, two-channel - on small trucks, etc.

A vital moment when driving is to have time to slow down. In performing a detour maneuver with braking, under normal road conditions, there is nothing difficult. It is enough to reduce the speed and adjust the steering trajectory.

In case of emergency braking, in an unforeseen situation, there is a threat of blocking the wheels. This is a skidding of the car, which leads to a loss of control of the vehicle. It is for such non-standard situations that the anti-lock braking system (ABS) was created.

The purpose of the anti-lock braking system is to prevent the braking wheels from locking up and to maintain control of the vehicle during extreme braking. That is, the possibility of making sharp maneuvers directly in the process of braking.

The probability of wheel blocking directly depends on the characteristics of the road surface, the degree of axle load and the uniformity of the tires installed.

The anti-lock braking system includes:

1. Speed ​​sensors - mounted on the wheels.
2. Control valves - elements of the pressure modulator, located in the caliper.
3. Control unit - coordinates the entire process: it is responsible for the operation of the valves, using the signal from the sensors.

The ABS Electronic Control Unit (ECU) contains thousands of parameters that are customized for a specific vehicle brand.

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

Even if two different cars have identical ABS systems, they will be set up very differently for sports car compared to SUV.

How does ABS work?

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

If the ABS system detects that one wheel is decelerating faster than the others (wheel lock symptom). Possibly low wheel friction due to contact with a surface such as ice.

The ABS control module detects the onset of blockage via a sensor in this wheel and responds by gradually reducing the brake pressure, quickly opening the hydraulic pressure release valve.

ABS also has the ability to pressurize back through the hydraulic motor. The system performs such actions with the control of the car quite quickly, thereby reducing the braking distance.

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

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

In the case of a non-uniform road surface (ice, sand, puddles, roadsides), it will be more reliable to use an independent multi-channel ABS. A multi-channel system is more expensive, but has greater efficiency in operation.

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

How to use ABS correctly

ABS works best with firm, steady pressure on the brake pedal. During ABS operation, some vibrations are felt, which are the opening and closing of the pressure release valves, as well as a sign that the system is working correctly. Do not release the pedal until you have come to a safe stop.

Braking with and without ABS

It's no secret that it's 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 grand scale outweigh the slightly longer braking distances.

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

ABS prevents the wheels from jamming and allows you to maneuver while braking.
Without ABS, the driver presses the brakes and the wheels jam. Despite holding the brake, the vehicle continues to move forward due to loss of control.

With properly performed threshold braking, a vehicle equipped with ABS can decelerate faster.
Many competitive racers would say they prefer their cars not to have the system. However, to get the maximum benefit, you need to repeatedly practice the threshold braking method.

Good test:

1. Find a test site and mark a cone that will act as a braking point
2. Accelerate to 100-120 kilometers per hour and apply the brakes as hard as you can in an ABS-equipped car
3. Repeat all without ABS

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

And one more piece of advice, if you have ABS, don't get into the habit of locking your wheels before you enter a corner - it's not the fastest way to slow down and can upset the car's ABS system.

Conclusion

Nowadays, cars with electronic system braking, acting independently on each of the wheels. In this case, the system does not exert any influence on the brake pedal.

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

Thank you for your attention, good luck on the road. Read, comment and ask questions. Subscribe to fresh and interesting articles of the site.

Many drivers, when purchasing a car, receive a set of options in it that they don’t know anything about, and even encrypted with various abbreviations. And the most common of them is ABS. ABS in a car - what is it and how to use it, our article will help you figure it out.
First, let's decipher and find out what ABS is for.
ABS (Antilock Brake System) - anti-lock braking system. That is, a system that does not allow the wheel to lock up during heavy braking, leaving the car in a controlled state. Since 2004, this system has been installed on all European cars, starting from the Norma configuration.
We will answer some questions that the happy owners of this option face on their cars.

ABS is an anti-lock braking system that prevents the wheel from locking up during hard braking, leaving the car in a controlled state.

The development of this system began back in the late 30s, and only in 1978 did motorists get the opportunity to install ABS on premium cars as an additional option.
The device of the ABS unit is a system of sensors that take into account the speed of rotation of the wheels, the brake fluid pressure sensor, the control module itself and the hydraulic unit as the final performer.

How does the ABS sensor work?

Initially, passive sensors were installed on cars that could not detect wheel speeds of less than 5-7 km / h.
Since the nineties of the last century, active sensors have been installed in the ABS. The main difference from passive sensors is that active sensors are powered by a power source.

ABS sensor on the front wheel

At first, the ABS system sensors were magnetoresistive, then more accurate sensors using the Hall effect began to be installed in the anti-lock brake systems.

At first, these were magnetoresistive sensors. They were an induction ring under voltage, which was installed on the wheel hub. During rotation, a magnetic field was created, which forced the electrons direct current change the trajectory, thereby increasing the resistance. It was the information about the change in resistance that the sensor transmitted ABS block management. They could pick up the speed of rotation from the moment the car started moving.
The design of modern ABS sensors in cars has changed in the last century. And this is due to the use of the Hall effect in them. Now its work is that a semiconductor wafer is installed in the sensor itself, a permanent magnet ring is installed on the hub, a magnetic field is created next to and when the wheel rotates, which causes electrons to move to one of the edges of the plate, the microcircuits convert the signal and transmit it to the control unit ABS. This sensor is more accurate, since it does not have a pulsed nature, but the microcircuits have raised the cost of the system, in addition, the microcircuit can fail due to road irregularities.

Where is the ABS wheel speed sensor located?

Speed ​​sensors are installed on each wheel in the hub. Its principle of operation is to record a change in the wheel speed, transmit an electronic signal to the control unit, where the program itself will generate further actions of the hydraulic brake system.

How does the ABS sensor work in simple words?

Driving a car with ABS and without anti-lock wheels

When the wheel is blocked, the sensor sends a signal to the ABS control unit, which in turn sends a command to reduce the braking force on the wheel.

Principle of operation ABS sensor is as follows. When braking hard, the system collects information that the wheel is not rotating, while the car is still moving. Further, information is transmitted from the ABS sensor to the main brake system, that it is necessary to reduce the braking force on this wheel, due to which the wheel lock is removed and the car comes out of the skid.

How the ABS control unit works

When driving, the ABS control unit continuously receives information and monitors the operation of the entire system as a whole and, at the slightest failure, turns on the anti-lock system.

Does your car have ABS?

If you bought a used car and wondered how to find out if your “iron horse” has an anti-lock system, then finding the answer to it is very simple. You need to pick up speed and press . As a result, if the ABS is installed and the sensors are not disabled, then you can feel the return of the braking force to the leg in the form of short-term shocks.

How to brake properly in a car with ABS?

ABS control unit on a car

To improve the performance of the ABS system, you need to remember and follow a few simple rules.

In theory, everything is simple in the event of emergency braking - the pedal to the floor, and the ABS unit will do the rest. But in practice this is not always the case.
In order to get the most out of your anti-lock braking system, greatly improve braking performance, reduce the chance of your vehicle's wheels locking up and skidding, improve maneuverability on wet pavement to reduce tire wear, you must follow simple rules:

1. The brake pedal must be pressed smoothly, with increasing effort.
2. Do not release the pedal when kickback.
3. Use tires according to the season.
4. Do not completely rely on the system, as the ABS unit does not always work correctly.

But, like everything, the system has its drawbacks. On the road with a loose surface, whether it is snow or sand, ABS will not help you, but on the contrary, it will lengthen the braking distance.

We hope that our article has helped you find answers to how, when and why ABS works. But, nevertheless, using it, be careful, keep your actions and the actions of the machine under control.

BUTBS. The words encrypted in this abbreviation are different: for example, in German Antiblockiersystem, in English Anti-lock Brake System, there is even a stable Russian-language phrase “anti-blocking system”, but they have the same translation and meaning. This is a system that prevents the wheels from locking during emergency braking and regulates the forces generated by brake mechanisms. The main task of the triune system is to enable the driver to control the car, maintain directional stability and provide the most effective deceleration during emergency braking.

Creation

The idea to create a system that prevents the wheels from locking was born before the Second World War. ABS was originally planned to be used in aviation. But the technologies and materials used at that time did not allow it to be implemented in mass production, and even more so on a mass-produced car. In 1964, Mercedes engineers, together with specialists from Teldix and Robert Bosch, got down to business. To begin with, we collected all the patents and reports over the past couple of decades, which mentioned the distribution of braking forces between the wheels.

The main elements of any ABS: control unit and hydraulic unit actuator (1), wheel speed sensors (2). The hydraulic unit regulates the pressure in the circuits of the brake system using a hydraulic accumulator, an electro-hydraulic reverse pump and control electro-hydraulic valves. The diagram shows a four-channel ABS, which is able to regulate the pressure separately in each of the four brake lines.
yellow - information cables;
red - brake circuit of the front right and left rear wheels;
blue - brake circuit of the front left and rear right wheels

All modern systems have four sensors that monitor the speed of rotation of the wheels, and four pairs of valves - two for each circuit or channel of the brake system. Such systems are called 4-channel. They allow you to individually adjust the braking force on each wheel, achieving the most effective deceleration.

Research has brought results, for example, helped to determine the functional diagram of the ABS. Sensors (then only on the front axle) measured the speed of rotation of each wheel. These measurements were recorded and compared by the control unit and, if necessary, gave corrections to the actuator to correct the pressure in any circuit of the brake system. On paper, everything went pretty smoothly. But in real situations, ABS did not work clearly, it reacted with delays to a change in the grip of the wheels with the road, and it was not famous for its reliability.

Back in 1936, Bosch registered a patent for a "mechanism to prevent the wheels of motor vehicles from locking up." But it was only with the introduction of electronics that engineers were able to develop an anti-lock braking system (ABS 1) suitable for use on a car.

One of the first significant steps towards mass production was the replacement in 1967 of mechanical sensors on wheels with non-contact ones using the principle of electromagnetic induction. The advantages are obvious: they do not wear out, are resistant to mechanical stress, there are no false positives. It was with such sensors in 1970 Mercedes presented to the public the first ABS c electronic control for cars, trucks and buses. The sensors transmitted signals to the unit, which controlled the hydraulic module installed between the main brake cylinder and calipers.

In 1978, Mercedes-Benz was the first automaker in the world to introduce ABS on a production S-Klasse. The option added 2217 marks to the price of the car. A little later, the same ABS 2 was tried on by the BMW 7-series. And today more than two-thirds of all new cars in the world are equipped with anti-lock brakes.

The principle of the first ABS is incorporated in the most modern system. The sensors monitor the speed of rotation of each wheel, the control unit compares the readings and sends commands to the solenoid valves of the hydraulic module that regulates the pressure in the brake system - a pair (inlet and outlet) for each circuit. During emergency braking, the valves operate at a frequency of several tens of times per second (15-20 Hz, depending on the system) - it is their chatter that we hear when the wheels are locked and unlocked. At the same time, the pressure in one or several circuits at once rises and is immediately released, and the pads, respectively, compress and release the disc, providing the same intermittent braking.

The first systems were based on analog technology, which often produced errors, the wiring diagrams themselves were complex and cumbersome. And the level of development of the "numbers" was then incomparably low - the first microprocessors, which appeared in the early 1970s, were not suitable for controlling the anti-lock braking system. Only 5 years later Bosch made a fully digital control unit. The electronic filling has become almost an order of magnitude more compact - the ABS 1 block consisted of about 1000 components, and only 140 were in the “brains” of the second generation system. In addition, the ABS began to work almost flawlessly and many times faster - the electronics processed the data from the wheel sensors in milliseconds and sent command pulses to the hydraulic module.

In the mid-1990s, anti-lock brake systems began to be installed on motorcycles. They prevent blocking front wheel and the flight of the rider through the steering wheel. The top diagram shows the advantage that ABS provides when braking the average motorcyclist on dry pavement from a speed of 100 km/h.

Many modern systems motorcycles operate even if the rider has applied only the rear or front brakes.

The further evolution of anti-lock systems went in two directions - the improvement of hydraulics and electronics. For example, consider the development of ABS from Bosch, which is not only the founder of the anti-lock braking system, but also the main supplier for most automakers, including Russian ones.

The most powerful supplier of ABS components is Bosch, which supplies components for most models. Bendix Corporation works for Chrysler and Jeep, Continental Automotiv Systems works for Ford, GM, Chrysler. Infiniti and Lexus use Nippondenso parts, and their countrymen Mazda and Honda use Sumitomo. Aisin Advics, Delphi, Hitachi, ITT Automotive, Mando Corporation, Nissin Kogyo, Teves, TRW and WABCO are also involved in the development and production of ABS components.

So, soon after the appearance of a compact digital filling, the control unit moved to the hydromodule. This not only made life easier for car assemblers and builders, but also reduced the cost of the system. The next generation of ABS 5, which has become not only lighter and faster, has received more advanced mechanics, including a block of new designs solenoid valves. Now the anti-lock braking system has made it possible to implement additional functions, in particular, the EBD (Electronic Brake Distribution) program, the metering braking force for each wheel separately, the TSC (Traction control system) program, which fights slippage, and the lateral dynamics control program - ESP (Electronic Stability Program). The implementation of these functions required engine management - so, for example, when the electronics detect a slip or cross slip, it automatically reduces the fuel supply.

Mechanical wheel sensors have been replaced by inductive ones. Their principle of operation is simple: when the car is moving, an electric current is induced in the sensor coil. Its frequency is directly proportional to the wheel speed. Over time, they began to measure not only the speed of rotation, but also the direction. Now on some models, sensors are built into wheel bearings.

Modern systems are built on a modular basis. For example, the ninth generation supports many functions that increase comfort and safety - electronics are able to prevent the car from rolling back when starting uphill, adjust the speed of descent from the mountain (implemented on crossovers and SUVs) and even automatically stop the car in an emergency (you can learn more about such systems). Moreover, the automaker acquires the set that he needs for a particular car. And the ABS developer assembles a unit for him from the appropriate electronic and hydraulic modules. In addition, this arrangement made it possible to produce systems for cars cheaper and more expensive. For example, for premium segment models, Bosch offers units with more complex mechanics. So, instead of a two-piston return pump, a six-piston one is installed in the hydraulic module. It very quickly reduces the pressure in the circuit, which is why there are almost no vibrations on the brake pedal.

A simplified diagram of the operation of the hydraulic unit as part of the ABS. For simplicity, the diagram considers the operation of a system with one wheel. In a four-channel system, there are four such circuits for each wheel.

What about in practice?

Not so long ago, we conducted a test that clearly shows the benefits of the anti-lock system. Detour of an obstacle with braking was carried out on a car with ABS and without it. The tires on the experimental Logans were the same - Barum Brilliantis with a dimension of 185/70 R14. For greater persuasiveness, a slippery coating was simulated - plastic soaked in soapy water. It was necessary to enter the "gateway" at a speed of 40 km / h and immediately begin an emergency (strong blow on the brake pedal - the driver was "scared") braking with simultaneous rebuilding.

Vehicle without anti-lock braking system

with the wheels turned out, without changing the trajectory, he knocked down an obstacle and continued to move on. The culprit is sliding friction in contact patches, locked wheels do not perceive lateral forces as they should, therefore, it is impossible to drive a car at this moment. I used intermittent braking, as taught in special courses, the effect on this type of coating is almost zero. Attempts to find the moment of blocking and apply search steering (search for the angle of rotation of the wheels when the car stops responding to the steering wheel) were also not crowned with particular success.

Logan with ABS

with a much more effective deceleration, it allowed even beginners to easily and without straining to get away from the obstacle the first time. The braking distance with ABS for this coating was on average 1.5 times shorter than that of Logan not equipped with anti-lock braking system. What is the trick? In intermittent braking with short-term blocking - ABS has time to slow down and brake each of the wheels 15 times in a second. While the wheel of a fraction of a second is rolling, you have the opportunity to set the direction (at this moment, rest friction is in the contact patches). At the same time, for each type of coating (set empirically during design and refinement), the most optimal degree of wheel slippage (15-20%) is maintained, at which deceleration is most effective. In addition, ABS doses the braking force on each of the wheels individually, preventing skidding.

Why didn't intermittent braking help on a car without ABS? Lock-unlock the wheels, unlike ABS, I have time for a maximum of three or four times per second - I act a priori more slowly. The degree of slippage is not optimal for me, therefore, braking is less effective. Unlike ABS, I act on all the wheels at once with the pedal, and this can cause demolition or skidding, because under the wheels there may be heterogeneous coatings, or the loading on the axles and sides can be changed. The trajectory with this method of braking can be learned to change slightly, but training is needed. The same is true for "tracking" braking. The conclusion is unequivocal - with ABS the car is safer.

However, not everything is as rosy as it might seem at first glance. In some cases, ABS can increase the stopping distance, for example, on ice and some unstable surfaces (loose ground, rolling gravel road or hard ground covered with dust, sand or snow). Worn-out shock absorbers and unscrupulous suspension settings can also add fuel to the fire... If at least one wheel breaks off the roadway for a long time during braking and blocks, the system, thinking that it has hit the ice, releases it, and at the same time reduces pressure in the hydraulic lines of the other wheels. The system in this case understands that the wheels are on heterogeneous surfaces and thus seeks to maintain directional stability. In addition, the very adequacy of the ABS setting on some modern models raises many questions. How to deal with these nuances, we'll talk next time.