Abbreviation for stability control system V.S.C. stands for Vehicle Stability Control.
Electronic constantly monitors the basic parameters of the vehicle’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 a skid may occur. The main sensors are sensors, and special yaw, acceleration and steering sensors are also used.
When the system ( V.S.C.) detects loss of control, it instantly transmits individual braking force to each wheel. Stability control also closes the throttle valve until the vehicle is brought out of the skid state, thereby compensating for the rotation of both the front and rear axles.
As a result of measuring lateral acceleration, yaw rate (skidding/steering out) and the rotation speed of each wheel, the exchange rate stability system ( V.S.C.) compares the driver's intentions (steering, braking) with the vehicle's response. The system then brakes one or more wheels and/or limits engine thrust to prevent skidding or skidding. However, it is obvious that such a system cannot override the physical limitations of a given chassis, and if the driver forgets about this, stability control system(VSC) will not be able to prevent an accident because it cannot overcome the laws of physics and provide better traction than is possible under the conditions.
Often the system V.S.C. operates much earlier than the driver begins to feel a loss of traction with the roadway. In this case, the start of system operation is indicated by a sound signal and the lighting of 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 electrohydraulic stability control systems. Different manufacturers call this system differently: ESP, VDS, DSC, VSC. Often, without reference to the car, the system bears the abbreviation 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 ( V.S.C.) reduces the number of accidents by 35% per year. It is also worth noting that if VSC 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. Don't blindly believe that you are safe. The road has always been and remains a place of increased danger. No system can compensate for the errors of speeding and aggressive driving. Yes, stability control system (vsc) can help in a difficult situation, but it is better not to lead to such moments. Take care of yourself and your loved ones!
29.02.2016
Modern cars are “stuffed” with electronics, which take on many different functions - controlling the engine, 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. Purpose. 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 cars are built in such a way that the rear axle takes on less of the load. Therefore, to improve vehicle stability on the road, the front wheels should lock before the rear wheels.
When heavy braking occurs, the load on the rear wheels decreases due to the shift in the center of gravity. As a result, instead of effective braking, you can get wheel locking. The purpose of the EBD system is to eliminate such a problem. In this case, the operating algorithm itself is set programmatically and is a kind of addition to the ABS system.
Thus, the braking force system is based on standard ABS, but at the same time performs a broader function. Common names for the system data are Elektronishe Bremskraftverteilung or Electronic Brake Force Distribution. The name of the system may vary among different manufacturers, but the principle of operation remains the same.
2. Construction features. If we consider the system in more detail, its operation is based on cyclical execution of tasks. In this case, several main phases are included in one cycle:
- maintaining blood pressure levels;
- releasing the pressure level to the required level;
- rise in pressure level.
The ABS control unit collects data from sensors that monitor wheel speed, and then compares the forces of the rear and front wheels. If the difference is greater than a specified value, then the principle of distribution of forces of the braking system is activated.
Based on the current difference in signals from each of the sensors, the control unit makes a decision regarding the exact moment to lock the rear wheels. At the same time, it gives a command to close the intake valves in the brake cylinder circuits (naturally, 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 this position. The pressure in the front circuit continues to increase until the wheels are locked.
If the rear wheels continue to lock, the exhaust valves open. As a result, the pressure in the brake cylinders of the rear wheels decreases to the required limit. If the angular speed of the rear axle wheels begins to increase 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 when the front wheels lock. At the same time, the ABS system is activated, preventing the wheels from locking and allowing the driver to maneuver even when the brake pedal is pressed sharply.
BAS system
1. Purpose. Among the auxiliary systems of modern cars, one cannot fail to mention the Brake Assist System, or BAS for short. This system is an algorithm that provides assistance in case of emergency pressing of the brake pedal. Compared to the system discussed above, BAS is more simple to operate. Its task is to assist the driver and “squeeze” the maximum out of the vehicle’s braking system.
The following situation can be cited. 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. With a BAS system, the “brains” do everything independently and give the command to increase the braking speed.
The peculiarity of the Brake Assist System is that it operates completely automatically and is independent of the driver’s actions. The electronics analyze when it is necessary to assist the driver and strengthen the action of the brakes. In this case, the decision is made after analyzing information from a whole group of different sensors.
2. History of appearance. The history of the appearance of this algorithm, which was created as an auxiliary system for standard ABS, deserves special attention. The first “swallows” on cars appeared in the early 70s of the last century. The pioneer was the Chrysler car.
At the present stage, everything has changed. If previously the Brake Assist System was installed only on expensive cars and was presented as an exclusive algorithm, then at the present stage such systems are installed on almost all classes of cars. Thus, the Euro NCAP committee recently summed up the results of installing BAS systems on cars from different manufacturers. Almost immediately after this, it was decided to introduce this device as mandatory for installation. In particular, a car does not receive a five-star test for safety if it does not have such a system on board. Such a revolutionary innovation helped push 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 production models. Already today they are available 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 installed only on Volvo or Mercedes cars.
3. Operating principle. A special feature of the BAS system is its ability to work with different braking systems, both hydraulic and air. To recognize the situation, various measuring instruments are used (installed at different points of the car):
- sensor that controls wheel speed;
- 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 monitors the pressure level 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.
Based on its operating principle, BAS controls 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 system cylinder. Thanks to the pressure created, the piston begins to move, and the brake system mechanism begins to compress. The BAS algorithm controls the pressure of the brake fluid in the cylinders, adding or decreasing the force of the braking system.
4. Types. Such systems are conventionally 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 installed on Mercedes and BMW cars. The peculiarity of the products is that they take into account a number of factors - the condition of the road, the force on the brake pedal, the distance to the car moving in front, and so on.
If the car's main focus 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 ability to regulate air pressure.
VSC system
In the automotive world, stability control has been known for a long time. At the same time, many car enthusiasts are still confused about the designations. The reason is simple - almost every manufacturer has its own name for this system. For example, in Volvo cars it is called VSA, in Hyundai, Kia and Honda - ESC, in Jaguar, Rover and BMW cars - DSC, in almost all brands of cars made in the USA and EU countries - ESP, in Toyota - VSC and so on. . However, regardless of the name, the principle of operation remains the same.
1. Purpose. Stability control is installed to improve the overall handling of the vehicle by identifying and adjusting certain functions in critical situations. Since 2011, this system has become mandatory for installation on cars in the EU countries, Canada and the USA. Using the system, you can maintain the car within a given trajectory.
2. Operating principle. A special feature of the VSC system from the manufacturer TRW is a combination of all the positive qualities and functionality of ABS, a new control system, as well as traction control of the machine's lateral slip. 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 car on slippery sections of the road.
The VSC sensor monitors the operating modes of the gearbox and power unit, pressure in the brake system and wheel rotation. After collecting data, it transmits the information to the control unit. The computer receives and processes information. After assessing the situation, he decides what command to issue to the actuators. The level of performance largely depends on the capabilities of the electronics, so in critical situations the system protects the self-confident driver and corrects obvious driving errors.
The operating principle of the device can be described with an example. The car is moving at speed and making a turn. In this case, the resulting force tries to move the car off the road - to the outside of the turn or to throw it to the side. If the turn occurs at high speed, then there is a high risk of drifting into a ditch. The driver realizes the mistake and begins to act completely inappropriately - he presses the brake and twists the steering wheel in the direction in which he is turning. This is where the VSC system makes a decision with lightning speed and prevents the wheels from locking. In this case, the braking forces are redistributed and the car is leveled. All this work of the system takes no more than a few seconds.
Dear fellow car enthusiasts, what is car directional stability? There is such a phenomenon, and now we will consider exactly what the vsc exchange rate stability system is.
You and I know very well that driving a car can be accompanied not only by pleasant experiences, but also by unforeseen situations, which, at best, result in expensive car repairs.
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 “the directional stability of the car, what is this?”
To prevent trouble, car manufacturers, counting on amateur riders and blonde women, equip their brainchildren with all sorts of equipment, the purpose of which is to prevent emergency situations.
Let's consider one of these technologies, which effectively ensures that cars follow the trajectory we have planned and do not present unpleasant surprises - skidding or something similar.
Vehicle directional stability, what is it and how is it different from dynamic stabilization?
Don't be fooled by the Latin abbreviation that follows the well-known name of the technology. The fact is that the same device produced by different vehicle manufacturers can have completely different names.
So, for example, the exchange rate stability system is well known as a dynamic stabilization system, and there are countless abbreviations for it - ESP, ESC, VSC, VDC, and so on. However, its essence and principle of operation depend little on the name; of course, there may be differences, but they are insignificant.
When does VSC operate?
So, why do we need stability control? As we already mentioned at the beginning of the article, its main function is to maintain the given trajectory of the car. Let's imagine a situation: the end of autumn, the first frosts, you, having pressed the gas pedal, are driving along a road on which yesterday's puddles have already become covered with a crust of ice. There is a small turn ahead, and you are entering it without slowing down, when suddenly one of the drive wheels (let’s imagine that you have a rear-wheel drive car) 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, horror for the driver. But if the car has a stability control system and it is activated, then in this case you will not even notice anything, except that the vehicle wobbles slightly with its stern. That's it.
Directional stability: the whole car is under control
Well, now let's delve into the principle of operation and design 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;
- actuators.
The condition of the car is monitored by a scattering of various sensors, namely: a steering angle sensor, pressure in the brake line, longitudinal and lateral acceleration of the body, wheel speed and angular speed of the car.
Based on the information received, the control unit assesses the situation in a split second, and if, in its opinion, the car is not moving as the driver wishes, it sends signals to the actuators to correct the situation. Devices that can be controlled by VSC electronics include:
- anti-lock brake valves integrated into the brake line;
- traction control elements;
- engine control unit;
- automatic transmission electronics (if, of course, the car has one);
- active wheel steering (also if equipped).
The consequence of the operation of the exchange rate stability system can be braking of the wheels, a change in the operating mode of the engine and gearbox, redistribution of torque along the axles or wheels, and so on.
Is VSC always useful?
By the way, despite all its usefulness, VSC technology also has its opponents. It is believed that for experienced drivers it is not only useless, but also an unnecessary burden. There may be some truth to this, which is why many cars equipped with stability control have a button to turn it off.
Sometimes deactivating it allows you to solve a difficult situation in a non-standard way, for example, by adding gas to get out of a skid, or it simply gives active driving enthusiasts the opportunity to tickle their nerves and enjoy a real drive behind the wheel.
I hope you are no longer tormented by the question: “what is vehicle directional stability?” 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.
In an effort to make cars as safe as possible, manufacturers equip them with all sorts of assistance systems designed to help the driver avoid danger at the right time. One of them is the exchange rate stability 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 one - do not allow the car to leave the specified trajectory in any driving mode, be it 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 in a turn with a set of speed, suddenly one side hits a sandy area. The traction force on the road 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.
The first vehicle stability control system appeared back in 1995, then called ESP or Electronic Stability Program, and since then it has become the most widespread in the automotive industry. In the future, the structure of all systems will be considered using its example.
Design of ESC, DSC, ESP, VDC, VSC, VSA systems
Stability control is a high-level active safety system. It is composite, consisting of simpler ones, namely:
- brake force distribution (EBD) systems;
- electronic differential lock (EDS);
This system consists of a set of input sensors (brake pressure, wheel speed, acceleration, turning speed and steering angle, and others), 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, pressure in the brake system), the other helps analyze the actual parameters of the vehicle’s movement (wheel speed, lateral and longitudinal acceleration, vehicle turning speed, brake pressure are assessed).
The ESP ECU, based on data received from the sensors, sends appropriate commands to the actuators. In addition to the systems included in 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 operates through the ABS hydraulic unit.
Operating principle of ESC, DSC, ESP, VDC, VSC, VSA systems
The stability control ECU operates continuously. Receiving information from sensors that analyze the driver’s actions, it calculates the desired vehicle movement parameters. The results obtained are compared with the actual parameters, information about which comes from the second group of sensors. The discrepancy is recognized by the ESP as an uncontrollable situation, and it comes into operation.
Movement is stabilized in the following ways:
- certain wheels slow down;
- engine torque changes;
- if the car has an active steering system, the steering angle of the front wheels changes;
- if the car has adaptive suspension, the degree of damping of the shock absorbers changes.
The motor torque is changed in one of several ways:
- the position of the throttle valve changes;
- fuel injection or ignition pulse is missed;
- the ignition timing changes;
- gear shifting in the automatic transmission is cancelled;
- in the case of all-wheel drive, torque is redistributed across the axles.
How necessary is a dynamic stabilization system?
There are many opponents of any auxiliary electronic systems in cars. All of them, as one, claim that ESC, DSC, ESP, VDC, VSC, VSA and others only discourage drivers and are also just a way to extract more money from the buyer. They also reinforce their arguments by the fact that 20 years ago, there were no such electronic assistants in cars, and, nevertheless, drivers coped well with driving.
We must pay tribute that there is some truth in these arguments. In fact, many drivers, believing that the assistance of ESC, DSC, ESP, VDC, VSC, VSA gives them almost unlimited possibilities on the road, begin to drive, neglecting common sense. The result can be very sad.
However, one cannot agree with opponents of active safety systems. Stability control system is necessary, at least as a safety measure. Studies show that a person spends much more time assessing the situation and reacting correctly than an electronic system. ESP has already helped save the life and health of many road users (especially novice drivers). If the driver has honed his skills to such an extent that the system, although it works, does not interfere with a person’s actions, he can only be congratulated.
Additional features of ESC, DSC, ESP, VDC, VSC, VSA systems
The exchange rate stability system, in addition to its main task - dynamic stabilization of the vehicle, can also perform additional tasks, such as preventing the vehicle from tipping over, preventing collisions, stabilizing the road train and others.
SUVs, due to their high center of gravity, are prone to rollover when entering a turn at high speed. To prevent this situation, a rollover prevention system, or Roll Over Prevention (ROP), is designed. In order to increase stability, the front wheels of the car 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. Initially, the driver is given audio and visual signals; if there is no reaction, the pressure in the brake system is automatically built up.
If the stability control system performs the function of stabilizing a road train on vehicles equipped with a towing device, then it prevents trailer yaw by braking the wheels and reducing engine torque.
Another useful function, which is especially necessary when driving on serpentine roads, is to increase the efficiency of the brakes when heated (called Over Boost or Fading Brake Support). It works simply - when the brake pads heat up, the pressure in the brake system automatically increases.
Finally, Dynamic Stability Control can automatically remove moisture from the brake discs. This function is activated when the windshield wipers are turned 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 gets on them is partially removed by the pads, and partly evaporates.
