29.02.2016
Modern cars are "stuffed" with electronics, which take on many different functions - engine control, brakes, fuel supply system, and so on. In turn, car owners do not always know what tasks a particular system performs. In this article, we will pay attention to such popular devices as VSC, BAS and EBD.
EBD system
1. Appointment. The abbreviation EBD stands for Electronic Brake Force Distribution or, translated into Russian, “Brake Force System”. The main task of the system is to prevent the rear wheels from locking by controlling the brakes on the rear axle of the car. This feature is easy to explain. Most of the machines are built in such a way that the rear axle takes on less of the load. Therefore, to improve the stability of the car on the road, the front wheels should be blocked before the rear ones.
When hard braking occurs, the load on the rear wheels is reduced due to a shift in the center of gravity. As a result, instead of effective braking, you can get wheel lock. The task of the EBD system is to eliminate such a problem. At the same time, the operation algorithm itself is set programmatically and is a kind of addition to the ABS system.
Thus, the brake force system is assembled on the basis of a standard ABS, but at the same time it performs a wider function. Common names for these systems are Elektronishe Bremskraftverteilung or Electronic Brake Force Distribution. Different manufacturers may have different names for the system, but the principle of operation remains the same.
2. Features of construction. If we consider the system in more detail, then its work is based on the cyclic execution of tasks. In this case, several main phases are included in one cycle:
- maintaining the pressure level;
- resetting the pressure level to the required level;
- rise in pressure level.
The ABS control unit collects data from sensors that control wheel speed, and then compares the efforts of the rear and front wheels. If the difference is greater than a predetermined value, then the principle of the distribution of forces of the brake system is started.
Based on the current difference in the signals from each of the sensors, the control unit decides on the exact moment of locking the rear wheels. At the same time, he gives the command to close the intake valves in the circuits of the brake cylinders (of course, for the rear axle). At this stage, the pressure is maintained at a given level and remains unchanged. In turn, the front wheel intake valves open and remain in that position. The pressure in the front circuit continues to increase until the wheels are blocked.
In the case when the rear wheels are further blocked, the exhaust valves open. As a result, the pressure in the brake cylinders of the rear wheels is reduced to the required limit. If the angular velocity of the rear axle wheels begins to grow and exceeds a certain parameter, then the pressure in the circuit will increase and the wheels will brake.
As a rule, the force distribution system stops working at the moment the front wheels lock. At the same time, the ABS system is connected to work, which does not allow the wheels to lock up and allows the driver to maneuver even when the brake pedal is pressed sharply.
BAS system
1. Appointment. Among the auxiliary systems of modern cars, one cannot fail to note the Brake Assist System or BAS for short. This system is an algorithm that provides assistance in the event of an emergency pressing the brake pedal. Compared to the BAS system discussed above, it is easier to operate. Its task is to assist the driver and "squeeze" the maximum out of the vehicle's braking system.
We can cite the following situation. The driver cannot “push” the brake to the limit (for example, the pedal is pressed too poorly or a bottle has fallen under it). As a result, the brake system worked, but not 100 percent. In the presence of the BAS system, the “brains” do everything on their own and give the command to increase the braking speed.
A feature of the Brake Assist System is the full automatism of work and independence from the actions of the driver. Electronics analyzes when it is necessary to help the driver and increase the brakes. In this case, the decision is made after analyzing the information from a whole group of different sensors.
2. History of appearance. The history of the emergence of this algorithm, which was created as an auxiliary system for a standard ABS, deserves special attention. The first "swallows" on cars have appeared since the beginning of the 70s of the last century. Chrysler was the pioneer.
At the present stage, everything has changed. If earlier the Brake Assist System was mounted only on expensive cars and was presented as an exclusive algorithm, then at the present stage such systems are mounted on almost all classes of cars. So, recently the Euro NCAP committee summed up the results of installing BAS systems on cars from different manufacturers. Almost immediately after that, it was decided to implement this device as a mandatory installation. In particular, a car does not receive a five-star safety test if it does not have a similar system on board. Such a revolutionary innovation has pushed manufacturers to create even safer and more efficient cars.
There is confidence that after some time, BAS systems will become mandatory and will be installed on all serial models. Already today they are on such popular cars as the Ford Focus or Chevrolet Aveo, the cost of which ranges from half a million to a million rubles. Despite the fact that previously such systems were mounted only on Volvo or Mercedes cars.
3. Working principle. A feature of the BAS system is the ability to work with different brake systems, both hydraulic and air. To recognize the situation, various measuring devices are used (installed at different points in the car):
- a sensor that controls the speed of the wheels;
- a sensor that records the speed of movement of the amplifier rod; the task of this device is to record the force of pressing the accelerator pedal;
- a sensor that controls the level of pressure in the brake system; here the principle is similar to the previous device; the difference is that this unit is used for hydraulics, and not for a vacuum booster as in the previous case.
According to the principle of operation, BAS controls the fluid pressure. It's easy to explain. The hydraulics are configured in such a way that the entire mechanism is controlled by a hydraulic drive. In this case, the brake pedal only transfers force from the foot to the brake cylinder. Due to the pressure created, the piston begins to move, and the brake system mechanism is compressed. The BAS algorithm takes control of the pressure of the brake fluid in the cylinders, adding or subtracting the force of the brake system.
4. Views. Such systems are conditionally divided into several categories and may vary:
- by the number of sensors that are used to take readings;
- by functionality.
The most reliable systems are mounted on Mercedes and BMW cars. The peculiarity of the products is taking into account a number of factors - the condition of the road, the force on the brake pedal, the distance to the car that is moving in front, and so on.
If in the car the main emphasis is on the pneumatic drive, then the compressed air is adjusted. The latter moves the piston and improves the quality of the brakes. This function is due to the possibility of regulating the air pressure.
VSC system
In the automotive world, the stability control system has been known for a long time. At the same time, many motorists are still confused in the designations. The reason is simple - almost every manufacturer of this system has some name of its own. For example, in Volvo cars it is called VSA, in Hyundai, Kia and Honda - ESC, in Jaguar, Rover and BMW cars - DSC, on almost all brands of cars made in the USA and EU countries - ESP, on Toyota - VSC and so on. . At the same time, regardless of the name, the principle of operation remains the same.
1. Appointment. The stability control system is mounted to improve the overall drivability of the machine by identifying and correcting certain functions in critical situations. Since 2011, this system has become mandatory for installation on cars in the EU countries, Canada and the USA. With the help of the system, you can keep the car within the boundaries of a given trajectory.
2. Principle of action. A feature of the VSC system from the manufacturer TRW is a combination of all the positive qualities and functionality of the ABS, a new control system, as well as traction control of the side slip of the machine. In addition, the exchange rate stability system takes on the functions of a spotter and eliminates the problems of each of the above systems. This is especially noticeable when operating the machine on slippery sections of the road.
The VSC sensor monitors the modes of operation of the gearbox and power unit, the pressure in the brake system and the rotation of the wheels. After collecting the data, it transmits the information to the control unit. The computer receives and processes information. After assessing the situation, he decides which command to give to the actuators. The level of performance largely depends on the capabilities of the electronics, therefore, in critical situations, the system secures the self-confident driver and corrects obvious errors in control.
The principle of operation of the device can be described with an example. The car moves at speed and makes a turn. In this case, the resulting force tries to move the car off the road - to the outside of the turn or throw it to the side. If the turn occurs at high speed, then there is a great risk of drift into a ditch. The driver understands the mistake and begins to act completely inadequate - he presses the brake and turns the steering wheel in the direction he is turning. This is where the VSC system makes a lightning-fast decision and prevents the wheels from locking up. In this case, the redistribution of braking forces occurs and the car is leveled. All this work of the system takes no more than a few seconds.
Dear fellow car enthusiasts, what is the directional stability of a car? There is such a phenomenon, and now we will consider exactly what the vsc exchange rate stability system is.
You and I know perfectly well that driving a car can be accompanied not only by pleasant experiences, but also by unforeseen situations, the result of which, at best, is an expensive car repair.
Of course, you say, a lot depends on the gasket between the steering wheel and the front seat - the driver, who sometimes does not ask this question “what is the road holding of the car?”
To prevent trouble, automakers, counting on amateur riders and blonde women, equip their offspring with all sorts of things, the vocation of which is to prevent emergency situations.
Let's consider one of these technologies, which effectively ensures that the cars go along the trajectory we have planned and do not present unpleasant surprises - drifts or something similar.
Vehicle directional stability what is it and how does it differ from dynamic stabilization
Don't be fooled by the Latin abbreviation following the well-known name of the technology. The fact is that the same device manufactured by different manufacturers of automotive equipment can have completely different names.
So, for example, the exchange rate stability system is well known as a dynamic stabilization system, and the abbreviations that designate it are generally countless - these are ESP, and ESC, and VSC, and VDC, and so on. Nevertheless, its essence and principle of operation depend little on the name, differences, of course, can be, but they are insignificant.
When does the VSC system work?
So why do we need a stability control system? As we mentioned at the beginning of the article, its main function is to save a given trajectory of the car. Imagine the situation: the end of autumn, the first frosts, you, having drowned the gas pedal, are driving along a road on which yesterday's puddles have already covered with a crust of ice. There is a small turn ahead, and you, without slowing down, enter it, when suddenly one of the driving wheels (let's imagine that you have a car with rear-wheel drive) hits the ice.
What will happen?
If the car is not equipped with VSC, then the consequences can be very sad - skidding, drifting off the trajectory, in a word, the horror of the driver. But if the car has a stability control system and it is activated, then in this case you won’t even notice anything, except that the vehicle will wag slightly astern. That's it.
Course stability: everything is under control
Well, now let's delve into the principle of operation and the device of the exchange rate stability system. It belongs to high-level technologies, which means that other systems and components of the car are under its control. The key elements of VSC are:
- a set of various sensors;
- electronic control unit;
- executive devices.
The state of the car is monitored by a scattering of various sensors, namely: a steering angle sensor, brake line pressure, longitudinal and lateral acceleration of the body, wheel speed and angular velocity of the car.
Based on the information received, the control unit evaluates the situation in a fraction of a second, and if, in its opinion, the car does not move as the driver wishes, it sends signals to the actuators to correct the situation. Devices that can be controlled by the VSC electronics include:
- anti-lock braking system valves built into the brake line;
- elements of the anti-slip system;
- engine control unit;
- automatic transmission electronics (unless, of course, it is in the car);
- active wheel steering (also if equipped).
The consequence of the operation of the stability control system may be the braking of the wheels, a change in the mode of operation of the engine and gearbox, the redistribution of torque along the axles or wheels, and so on.
Is VSC always helpful?
By the way, despite all its usefulness, VSC technology has its opponents. It is believed that for experienced drivers it is not only useless, but also an unnecessary burden. Perhaps there is some truth in this, and that is why many cars equipped with the stability control system have a button to turn it off.
Sometimes its deactivation allows you to solve a difficult situation in a non-standard way, for example, to add gas to get out of a skid, or simply gives lovers of active driving the opportunity to tickle their nerves and enjoy a real drive behind the wheel.
I hope you are no longer tormented by the question: "car directional stability, what is it"? But be that as it may, friends, always be careful on the roads and do not rely on the smart electronics of the car for everything.
I advise you to get acquainted, within the framework of security systems, with.
Today we will try to explain and answer the question: What is VSC in a car? In fact, Vehicle Stability Control, or in the abbreviation VSC, is a vehicle stability control system.
Check VSC is installed in the car in order to constantly monitor its speed and direction of movement. This electronic system continuously compares the parameters actually produced during the maneuvers of the machine with the acceleration or deceleration set by the driver. VSC helps replace lost traction to help prevent skidding.
The stability control system is a necessary assistance to the driver in maintaining control of the vehicle when driving under normal conditions and during difficult weather situations. However, the presence of VSC in the car is not a panacea and one hundred percent protection against
The safety of the driver by and large depends on him: on his experience and driving style, compliance with traffic rules and keeping the car in proper order. You can not rely on the system, ignoring elementary safety rules. The degree to which VSC is effective in preventing loss of control is directly related to the amount of speed, the driver's reaction, the condition and quality of the tires on the wheels, as well as the availability and quality of the road surface.
The system allows you to control the stability when maneuvering the car. Check VSC using electronic sensor data to manage over or under maneuverability in critical situations. Insufficient maneuverability contributes to the loss of traction of the car on the front wheels, causing the front axle to shift. Excessive maneuverability leads to a loss of traction by the rear wheels and, accordingly, the rear axle moves away from the vehicle's trajectory.
By braking with one wheel or several at once, the system limits the thrust of the car engine in order to prevent skidding or overshooting. However, the driver should remember that VSC is not omnipotent and cannot, violating the laws of physics, provide proper grip in critical situations.
Conducted independent international studies have proven the invaluable benefits and effectiveness of the electronic VSC system in providing real assistance to the driver in maintaining control of the car, minimizing the risk of car collisions and thereby saving human lives. Provided that this system would function in every car, then 10,000 people would not die in accidents every year.
However, the opinions of the direct users of this electronic system were divided into opposite ones. Some consider it the most important means of safety (like the belts of the same name). Others claim that "guaranteed safety" only encourages the driver - the reckless driver to make daring decisions and risky maneuvers when driving a car. And in general, such "electronic things" indulge in aggressive and absent-minded driving.
Some experienced drivers refuse to use the stability control system, claiming that it deprives them of the opportunity to experience the real dynamics of the purchased car. And in general, the "electronic nanny" spoils all the pleasure derived from independent driving.
Therefore, in order to please all customers at once, some manufacturers, when installing the VSC system in a car, also provide a button to turn it off. And in some cars there is a function to change the settings of the electronic system so that it works only with a significant skid or drift.
Another important claim to the VSC is the permission to "reckless drivers" at a fairly high speed to drive a car steadily. And when the unfortunate racer “crosses the line”, the collision occurs at “cosmic” speed and entails dire consequences.
However, the reasonable use of the VSC system can improve the comfort and safety of driving a car, significantly reduce the number of deaths during accidents.
In an effort to make cars as safe as possible, manufacturers equip them with all kinds of assistance systems designed to help the driver avoid danger at the right time. One of them is the stability control system. On cars of different brands, it can be called differently: ESC for Honda, DSC for BMW, ESP for the vast majority of European and American cars, VDC for Subaru, VSC for Toyota, VSA for Honda and Acura, but the purpose of the exchange rate stabilization system is the same - prevent the vehicle from deviating from a given trajectory in any driving mode, whether it is acceleration, braking, driving in a straight line or in a turn.
The operation of ESC, VDC, and any other can be illustrated as follows: the car is moving into a corner with a set of speed, suddenly one side hits a sandy area. The traction force changes dramatically, and this can lead to skidding or drifting. To prevent departure from the trajectory, the dynamic stabilization system instantly redistributes torque between the drive wheels, and, if necessary, brakes the wheels. And if the car is equipped with an active steering system, the angle of rotation of the wheels changes.
For the first time, the car's stability control system appeared back in 1995, then called ESP or Electronic Stability Program, and since then has become the most common in the automotive industry. In the future, the device of all systems will be considered on its example.
Design of ESC, DSC, ESP, VDC, VSC, VSA systems
The stability control system is a high-level active safety system. It is a composite, consisting of simpler ones, namely:
- brake force distribution systems (EBD);
- electronic differential lock (EDS);
This system consists of a set of input sensors (pressure in the brake system, wheel speed, acceleration, turning speed and steering angle, etc.), a control unit and a hydraulic unit.
One group of sensors is used to evaluate the driver's actions (data on the steering wheel angle, brake pressure), the other helps to analyze the actual parameters of the car's movement (the wheel speed, lateral and longitudinal acceleration, car turning speed, brake pressure are estimated).
The ESP ECU, based on the data received from the sensors, issues the appropriate commands to the actuators. In addition to the systems that make up the ESP itself, its control unit interacts with the engine control unit and the automatic transmission control unit. From them, he also receives the necessary information and sends them control signals.
The dynamic stabilization system works by means of an ABS hydraulic unit.
The principle of operation of the ESC, DSC, ESP, VDC, VSC, VSA systems
The stability control ECU operates continuously. Receiving information from sensors that analyze the actions of the driver, it calculates the desired parameters of the car's movement. The results obtained are compared with the actual parameters, information about which comes from the second group of sensors. The mismatch is recognized by ESP as an uncontrollable situation, and it is included in the work.
The movement is stabilized in the following ways:
- certain wheels are braked;
- engine torque changes
- if the car has an active steering system, the angle of rotation of the front wheels changes;
- if the car has an adaptive suspension, the degree of damping of the shock absorbers changes.
Motor torque is changed in one of several ways:
- throttle position changes;
- fuel injection or ignition pulse is skipped;
- the ignition timing changes;
- gear shifting in automatic transmission is canceled;
- in the case of all-wheel drive, the torque is redistributed on the axles.
How necessary is the dynamic stabilization system
There are many opponents of any auxiliary electronic systems in cars. All of them, as one, argue that ESC, DSC, ESP, VDC, VSC, VSA and others only discourage drivers and, moreover, are just a way to get more money out of the buyer. They support their arguments by the fact that even 20 years ago, there were no such electronic assistants in cars, and, nevertheless, drivers did an excellent job of driving.
We must pay tribute to the fact that there is some truth in these arguments. In fact, many drivers, believing that the help of ESC, DSC, ESP, VDC, VSC, VSA gives them almost unlimited possibilities on the road, start driving, neglecting common sense. The result can be very sad.
However, one cannot agree with the opponents of active safety systems. The system of exchange rate stability is necessary, at least as a safety measure. Studies show that a person spends much more time assessing the situation and responding correctly than an electronic system. ESP has already helped save the lives and health of many road users (especially novice drivers). If the driver has perfected his skills to such an extent that the system, although it works, does not interfere with the actions of a person, he can only be congratulated.
Additional features of ESC, DSC, ESP, VDC, VSC, VSA systems
The course stability system, in addition to its main task - the dynamic stabilization of the car, can also perform additional tasks, such as preventing the car from tipping over, preventing collision, stabilizing the road train and others.
SUVs, due to the high center of gravity, are prone to tipping over when entering a turn at high speed. To prevent such a situation, a rollover prevention system, or Roll Over Prevention (ROP), is designed. To increase stability, the front wheels of the vehicle are braked and engine torque is reduced.
To implement the collision avoidance function, the ESC, DSC, ESP, VDC, VSC, VSA systems additionally require adaptive cruise control. First, the driver is given audible and visual signals, if there is no reaction, the pressure in the brake system is automatically increased.
If the stability control system performs the function of stabilizing the road train on vehicles equipped with a towing device, then it prevents the trailer from yawing by braking the wheels and reducing engine torque.
Another useful feature that is especially needed when driving on serpentine roads is to increase the effectiveness of the brakes when they heat up (called Over Boost or Fading Brake Support). It works simply - when the brake pads are heated, the pressure in the brake system automatically increases.
Finally, the dynamic stabilization system can automatically remove moisture from the brake discs. This function is activated when the wipers are on at speeds above 50 km/h. The principle of operation is a short-term regular increase in pressure in the brake system, as a result of which the pads are pressed against the brake discs, they heat up and the water that has fallen on them is partially removed by the pads, and partially evaporates.
Abbreviation of stability control system VSC stands for Vehicle Stability Control.
Electronic constantly monitors the main parameters of the car's movement: speed and direction of movement. At the same time, the system constantly compares the received parameters from the sensors with the actions of the driver and works out the loss of vehicle traction, due to which skidding may occur. The main sensors are sensors, and special yaw, acceleration and steering sensors are also used.
When the system ( VSC) detects loss of control, it instantly applies individual braking force to each wheel. Stability System also closes the throttle until the vehicle is out of a skid, compensating for both front and rear axle spin.
As a result of measuring lateral acceleration, yaw (drift/steer) and rotation speed of each of the wheels, the directional stability system ( VSC) compares the driver's intentions (steering, braking) with the car's response. The system then brakes one or more wheels and/or limits engine power to prevent skidding or overshooting. However, it is clear that such a system cannot override the physical limitations of a given chassis, and if the driver forgets this, stability control system(VSC) will not be able to prevent an accident, as it cannot overcome the laws of physics and provide better traction than is possible under these conditions
Often the system VSC works much earlier than the driver begins to feel the loss of traction with the roadway. At the same time, the beginning of the system operation is indicated by a sound signal and an indicator on the dashboard.
First Vehicle Stability Control (VSC) was released by Robert Bosch GmbH in 1995 and was installed on top versions of Mercedes-Benz and BMW cars. There are many names for an electro-hydraulic stability control system. Various manufacturers call this system in their own way: ESP, VDS, DSC, VSC. Often, without reference to the car, the system is abbreviated as ESC (Electronic Stability Control). In any case, such a system includes anti-lock braking system (ABS), traction control (TRC) and yaw control (rotation of the car around a vertical axis).
According to statistics, the exchange rate stability system ( VSC) reduces the number of accidents by 35% per year. It is also worth noting that if the VSC system were installed on all cars, more than 10,000 accidents could be avoided within one year.
However, I want to note that the presence of this system does not make the driver omnipotent. Do not blindly believe that you are safe. The road has always been and remains a place of increased danger. No system is capable of compensating for speeding and aggressive driving errors. Yes, stability control system (vsc) can help in a difficult situation, but it is better not to bring it to such moments. Take care of yourself and your loved ones!
