In many modern cars in the "complete set" section, a huge number of abbreviations are indicated. And if a sufficiently large number of people know what ABS is, then how it works electronic system brake force distribution EBD EBV, few are devoted to the intricacies of the car's EBD system.

So, EBD is a brake force distribution system. It is needed in order to prevent the rear wheels from blocking. EBD manipulates force on rear axle. The question immediately arises, why is this necessary? The point is that many modern cars receive a much greater load on the front axle than on the rear. That is why the locking of the front axle should come a moment earlier, which will allow the car to maintain directional stability. At the moment of very sharp braking, the above force increases due to the displacement of the center of gravity of the machine. It leads to incorrect work familiar ABS. Thus, EBD is an excellent addition to the standard "traction control".
There are two common abbreviations for the brake force distribution system:

1. EBD - originated from in English"electronic brake force distribution".
2. EBV- german version, found mainly in cars from Germany "Elektronische Bremskraftverteilung".

Working principle of EBD EBV

Just like its older brother ABS, EBD has a peculiar cycle in which the system works:

• The first phase is pressure retention.
• The second phase is pressure reduction.
• The third phase is a repeated set of the desired pressure.

This system starts working after the block ABS controls, after analyzing the information from the sensors on both axles, determines that the forces on both axles are not equal. It is the difference in these readings that shows when the rear axle will begin to lock. The next step is to close the valves. brake system leading to rear axle. The pressure remains constant. This is what "retention" is.

In the event that the above did not help and the wheels are still blocked (slip), the system sends an impulse to open the exhaust valves, which allows you to reduce the pressure. This is phase number 2.

The turn of the last phase comes when the angular velocity of the rear axle wheels exceeds the established limits. Then the pressure is deliberately increased. After that, as a rule, there is a redistribution of effort, and the front wheels begin to block. At this point, the ABS system comes into play.

The brake force distribution system is designed to prevent blocking rear wheels by controlling the braking force of the rear axle.

A modern car is designed so that the rear axle has less load than the front. Therefore, in order to save exchange rate stability vehicle, the front wheels must lock before the rear wheels.

When the car brakes hard, there is an additional reduction in the load on the rear axle, as the center of gravity shifts forward. And the rear wheels, at the same time, may be blocked.

The brake force distribution system is a software extension of the anti-lock brake system. In other words, the system uses structural elements ABS systems in a new quality.

Common trade names for the system are:

• EBD, Electronic Brake Force Distribution ;
• EBV, Elektronishe Bremskraftverteilung .

The principle of operation of the brake force distribution system

The operation of the EBD system, as well as the ABS system, is cyclical. The cycle of work includes three phases:

1. pressure retention;
2. pressure release;
3. increase in pressure.

The ABS control unit compares the braking forces of the front and rear wheels based on data from the wheel speed sensors. When the difference between them exceeds a predetermined value, the algorithm of the brake force distribution system is activated.

Based on the difference in the sensor signals, the control unit determines the beginning of the blocking of the rear wheels. It closes the intake valves in the circuits brake cylinders rear wheels. The pressure in the rear wheel circuit is kept at the current level. The front wheel intake valves remain open. The pressure in the circuits of the brake cylinders of the front wheels continues to increase until the blocking of the front wheels begins.

If the rear axle wheels continue to block, the corresponding exhaust valves open and the pressure in the rear wheel brake cylinder circuits decreases.

When the angular velocity of the rear wheels exceeds the set value, the pressure in the circuits increases. The rear wheels are braked.

The work of the brake force distribution system ends with the beginning of the blocking of the front (driving) wheels. At the same time, the ABS system is activated.

When you press the appropriate pedal, the brake mechanism is activated and the wheels begin to slow down rapidly. This scheme of operation of the brakes is far from ideal, and in budget cars the response is sharp and excessively rapid, which causes inconvenience to the driver and reduces the safety of his movement. An excellent invention was the brake force distribution system. It raises many questions and still remains incomprehensible to car owners. We will correct this situation and figure out what EBD is in a car.

How EBD works

Already from the name it becomes clear that it is aimed at the competent distribution of braking force between all wheels. An example will make it easier to understand the scheme of work. Let's imagine a standard situation for every motorist - a ramp to the side of the road. In this case, a pair of right wheels end up on a dirt road, the characteristics of which differ significantly from the asphalt surface, even if not of very high quality. The left wheels remain on the pavement.

The characteristics of the movement of the car differ significantly depending on the type of road surface: friction force, grip level, different braking. If the car starts moving in the situation we have described, then it can be skidded with a high degree of probability. But only if the EBD brake force distribution system was not provided by the manufacturer. In more expensive and modern cars, this development will direct more braking force to the left wheels, and weaken the brake force on the right wheels. As a result, the driver will not lose possession of the car for a second and will keep the situation under control.

EBD work organization

In short, the electronic brake force distribution system is responsible for monitoring the situation on the road, reading the data received by the ABS unit, and distributing the force that is sent to each wheel unit.

Each wheel has sensors that send data to the ABS unit. Rotational speed, internal pressure and degree of adhesion are taken into account. The information is analyzed separately for each wheel, therefore, the calculation of the necessary distribution of the braking impulse is carried out for each wheel separately. allows you to achieve high accuracy in the operation of the system and minimize the likelihood of errors and errors.

Is everything so good in EBD

No electronic system is so perfect as to work without errors and be able to foresee everything. possible options. It may well happen that the vehicle's electronics will incorrectly analyze a short-term reduction in traction, which is typical for Russian roads. In this case, electronic brake force distribution (EBD) will work more to harm than good.

The efficiency of this system is reduced. The usual braking process, without the use of smart electronics, will achieve best result. This feature is explained by the presence of a deep tread on winter wheels, which in the locked position will themselves work to reduce the braking distance.

These shortcomings are more than offset by the advantages that are characteristic of EBD:

• rational distribution of braking force;
• individual calculation for each situation;
• assistance in maintaining the correct trajectory of movement;
• minimizes the likelihood of drifts and drifts;
• maintaining efficiency regardless of the type of braking.

Specialists do not stop working on improving the system we are considering, and, perhaps, very soon car owners will be able to use absolutely. In the meantime, let's be content with the existing electronic device to distribute the braking force.

The abbreviation EBD stands for "Electronic Brake Distribution", which means "electronic brake force distribution system". EBD works in conjunction with and is its software addition. It allows you to more effectively distribute the braking force on the wheels depending on the vehicle load and provides better controllability and stability when braking.

Principle of operation and design of EBD

Stopping distance with and without EBD

During emergency braking, the center of gravity of the car is shifted to the front, reducing the load on the rear axle. If at this point the braking forces on all wheels are the same (which happens in vehicles that do not use brake force control systems), the rear wheels may be completely blocked. This results in loss due to lateral forces, as well as skidding and loss of control. Also, the adjustment of the braking forces is necessary when loading the car with passengers or luggage.
In the case where braking is performed in a corner (with the center of gravity transferred to the wheels running on the outer radius) or arbitrary wheels hit surfaces with different grip (for example, on ice), the action of one ABS system may not be enough.
This problem can be solved by the brake force distribution system, which interacts with each wheel separately. In practice, this includes the following tasks:

• Determining the degree of slippage on the road surface for each wheel.
• Change in pressure working fluid in and distribution of braking forces depending on the adhesion of the wheels to the road.
• Preservation of course stability under the influence of lateral forces.
• Reducing the likelihood of the car skidding during braking and turning.

Main elements of the system

The layout of the elements of EBD (ABS) in the design of the car

Structurally, the brake force distribution system is implemented on the basis of the ABS system and consists of three elements:

• Sensors. They record data on the current rotational speed of each wheel. In this case, EBD uses ABS sensors.
• The electronic unit control (common for both systems control module). Receives and processes speed information, analyzes braking conditions and actuates the appropriate brake valves.
• Hydraulic block of the ABS system. Performs pressure adjustment in the system, changing the braking forces on all wheels in accordance with the signals given by the control unit.

The brake force distribution process

The distribution of braking forces along the axes of the car

In practice, the operation of the electronic brake force distribution system (EBD) is a cycle similar to the operation ABS systems and consisting of the following steps:

• Analysis and comparison of braking forces. It is carried out by the ABS control unit for the rear and front wheels. If the specified value is exceeded, the algorithm of actions pre-installed in the memory of the EBD control unit is activated.
• Closing valves to maintain the set pressure in the wheel circuit. The system determines the moment when the wheel lock starts and fixes the pressure at the current level.
• Opening exhaust valves and reducing pressure. If the risk of blocking the wheels persists, the control unit opens the valve and reduces the pressure in the circuits of the working brake cylinders.
• Increasing pressure. When the wheel speed does not exceed the lock threshold, the program opens the intake valves and thus increases the pressure in the circuit created by the driver when the brake pedal is pressed.
• At the moment the front wheels start to lock, the brake force distribution system is turned off and ABS is activated.

Thus, the system continuously monitors and most effectively distributes the braking force on each wheel. However, if the car is carrying luggage or passengers on rear seats, the distribution of forces will be carried out more evenly than with a strong shift in the center of gravity to the front of the car.

Advantages and disadvantages

The main advantage is that the electronic brake force distribution makes it possible to realize the vehicle's braking potential in the most efficient way, depending on external factors (loading, cornering, etc.). At the same time, the system works automatically, and it is enough to press the brake pedal to start it. Also, the EBD system allows you to brake during long turns without the risk of skidding.
The main disadvantage is that, in the case of using studded winter tires, when braking using the EBD brake force distribution system, the braking distance increases compared to conventional braking. This minus is also typical for classic anti-lock systems.
In fact, the EBD electronic brake force distribution system is an excellent addition to ABS, making it more advanced. It comes into operation before the start of the anti-lock braking system, preparing the car for more comfortable and efficient braking.

Reading 3 min.

The EBD system is not new technology. Engineers have been developing it since the last century. ABS and EBD are designed to work together, which increases their overall efficiency.

Today, you will not surprise anyone with electronics in a car. More nodes in modern transport are managed and controlled not by mechanics and not by a person, but by microchips. Such a rapid breakthrough in scientific and technological progress has allowed many developers to take care of improving the safety of drivers and passengers. Among all kinds of innovations, the employees of the design bureaus had to work on improving the car stop system.

New developments have helped to avoid jamming of the wheels with emergency pressure on the brake pedal.

Progress has not stood still, and new technologies have begun to appear in this area aimed at ensuring a safe ride. Among them is EBD (Electronic Brake Distribution), an electronic system that distributes braking forces. What are the benefits of this development and what does it represent?

A bit of history

The EBD system is not a new technology. Engineers started developing it back in the last century, and by the end of the 80s, the system could be found in new cars. The developers of the automotive giants have noticed that the system anti-lock braking(ABS) does not cope with all the task assigned to it. During the research, it became clear that the main load during braking falls on the front wheels.

The anti-lock braking system, in turn, made it possible to avoid jamming when braking the front, however, the rear wheels were in a stationary state, which led to the vehicle skidding.

During the research of design bureaus, it was found that the distribution of braking forces, at the time of braking itself, occurs evenly on the entire chassis of the car. However, the wheels themselves were in completely different conditions. The decisive factor was the adhesion of the wheel to the braking surface. As a result, the behavior of each chassis was individual. So, since the blocking was on the rear wheels, this led to the fact that the body of the transport began to throw to the side. The front ones were free from the stopper, which allowed the driver to control the transport. In this regard, it became necessary to develop a brake force distribution system.

How it works

The EBD design includes:

1. Wheel speed sensors. The same sensors transmit data for the anti-lock braking system.

2. Electronic system control unit. Like the sensors, the unit is also connected to the ABS system.

3. Valves brake line. Includes check valves and pressure reducing valves.

In the moment emergency braking the anti-lock braking system is activated, which starts the brake force distribution mechanism. Information from sensors about the speed of rotation of the chassis is transmitted to the control unit.

Further, the system analyzes the received information, setting which wheels have the maximum grip with the road surface. Based on the results obtained, the system carries out the distribution of braking forces. The signal is sent from the control unit to the brake system valves, which, by regulating the pressure, distribute the load: slightly more for the rear wheels than for the front ones. This balances the forces on the chassis.

At the same time, the anti-lock system receives a signal that the brake forces have been successfully distributed and unlocks the wheels. This allows the driver to keep the car stable on the road, which makes driving safer. ABS and EBD are designed to work together to improve their overall performance.