Description and principle of operation of the TCS traction control system. What is TRC in a car? What is traction control in a car

Find out how the traction control system of a car works and what types of it exist. Schemes and videos about the principle of the system.

Having passed a long period of time, and a difficult path, from simple systems, up to entire complex systems that are combined into several traction control systems.

What is an anti-slip system

The traction control system, or APS for short, is also called "traction control (PBS)", on English language you can also see two names for this technology - Dynamic Traction Control (DTC) and Traction control system (TCS), in German it is called Antriebsschlupfregelung (ASR).

The traction control system is a secondary safety feature that works with the ABS anti-lock braking system on cars, trucks and SUVs. This electro-hydraulic system of the car makes it easier to drive the car on wet roads (it prevents the loss of traction by constantly monitoring the slip of the driving wheels of the car). Depending on the company of the car manufacturer, anti-slip technology has the following names (types):

• ASR - installed on cars from companies such as Mercedes (as well as ETS), Volkswagen, Audi.
• ASC - installed on BMW cars.
• A-TRAC and TRC - on Toyota vehicles.
• DSA - available on Opel vehicles.
• DTC - mounted on BMW vehicles.
• ETC - installed on Range Rover vehicles.
• STC - on Volvo cars.
• TCS - installed on Honda vehicles.

ASR system and the nuances of its work

ASR helps prevent loss of traction at the vehicle's wheels by using an electro-hydraulic system that controls the engine and brakes in adverse conditions. road conditions or if the driver uses excessive acceleration and the wheels begin to slip on the pavement. The ASR system helps the driver avoid making mistakes in adverse road conditions and helps the driver maintain control of the vehicle.

Professional drivers complain that ASR affects vehicle performance, but this standard equipment in high-performance vehicles helps beginners and drivers who often overestimate their ability to control their car in adverse weather conditions and regain driver control in unforeseen circumstances.

ASR technology has been in most cars and motorcycles since around 1992. And it traces its history back to the early 1930s, when Porsche developed the limited-slip differential, which allows one wheel to spin slightly faster than the other to improve traction. The ASR system is closely related to ABS. From the first users of the ASR, which was already complemented by the ABS system, was BMW in 1979.

How the ASR system works

Main functions and purposes of PBS

The ASR system is based on the ABS anti-lock braking system. The functions implemented in the ASR are differential lock and torque control.

How the traction control system works and its nuances

Description of other traction control systems of cars

The principle of operation of the TRC is the same as the ASR, but all the safety technologies of the car are connected to the work.

Video about how the TRC traction control system works

Advantages in the work of the anti-slip system of the car

• Reduced chances of tire damage.
• Increased engine resources.
• Driving safety in corners, on wet roads.
• Driving safety on a winter road.
• Safe and comfortable driving on wet, winter and other poor grip roads.
• Helps save fuel.
• Good handling and predictability on the road, which helps to feel comfortable on the track.

TRC (TRaction Control) is one of the names of the traction control system. It so happened that different car manufacturers call it differently, in the descriptions of car models you can find the abbreviations ETS, ASC, ASR, STC and many others. But regardless of the name, the task of this system is to prevent the slipping of the front wheelset of your car.

Slippage, as a rule, appears when starting or trying to accelerate sharply on slippery or viscous surfaces: on an icy road, in sand or mud: the engine roars, the wheels spin idle, and the car does not move or moves at the same speed.

The device and principle of operation of the TRC (TRaction Control) system

TRC (TRaction Control) is a system that simultaneously controls both braking and engine traction enhancement processes. This system not only eliminates the slipping of the driving wheelset, but also regulates the traction force of the engine - to values ​​that are optimal for the specific road surface on which the car is moving.

Thanks to TRC, the driver is relieved of difficult manipulations with the gas pedal when slipping, and the car itself acquires exceptional stability when starting abruptly from a stop or quickly accelerating on slippery roads.

However, all automakers that supply their offspring with traction control systems, including Toyota, which installs the TRC system on cars (for Toyota C-class it is optional, and for all classes above it is included in the basic package of a car), emphasize that the traction control system is not an alternative to smart and safe driving.

In addition, manufacturers remind that how effective the traction control system, including TRC, will be, depends on the condition of the road and the degree of tire wear.

Most traction control systems these days are electro-hydraulic. Of course, different manufacturers have their own know-how and anti-slip systems may differ slightly in design from each other. But still, in general, their principle of operation can be considered on the example of TRC.

TRC in the car controls the traction of the motor due to the ability to control air damper, ignition delays in the cylinders (in one of them or in several at the same time). Also TRC (TRaction Control) can increase or decrease the fuel supply to the engine and control the brake actuator.

At its core, TRC is a necessary component of the car's safety system, especially important for cars with powerful engine, the slightest excess of traction which leads to slipping of the drive wheels.

Without an adequately functioning TRC, a modern SUV is unthinkable, which is a priori obliged to overcome slippery and wet roads with honor, or their complete absence. Can't do without TRC and racing models, the traction control system allows them to exit the turn with acceleration without wheel slip.

You can sometimes hear the opinion that TRC deprives an experienced driver of the control he needs over the car. Moreover, this system is not just unpopular among motorsport fans - TRC is regularly tried to be outlawed in some of its forms, up to Formula 1, where, due to disputes around TRC, they even had to adjust the rules a few years ago.

However, for most motorists TRC is a reliable assistant. This system not only allows you to start or accelerate without skidding on wet or icy roads, it also makes it much easier for a front-wheel drive car to corner.

It is known that on difficult turns in some cases there comes a moment when the front wheels are unable to pull the car and at the same time turn without skidding. TRC (TRAction Control) also allows you to return the car to controllability.

For almost a quarter of a century, cars and trucks, equipped with advanced security systems, install traction control systems. From the name of this system it is clear that it does not allow the wheels of the car to slip at the right time. The traction control system of a car is the second security system after ABS (anti-lock braking system). These two latest systems work in pairs and do not allow the wheels to block or slip. Drivers who are interested in electronic security systems often want to understand how the traction control system works.

The traction control system is abbreviated (PBS) translated into English as Traction control system (TCS). German automotive engineers call it Antriebsschlupfregelung (ASR). These systems include a set of measures to prevent axle box on roads with insufficient grip.

The programs programmed into the car's brains are optional and can be turned off. But you need to do this every time anew after turning off the ignition. And not everyone does it.

Since the beginning of the assembly of cars with such systems, it has become much easier and safer to manage them. Other drivers have never turned off these systems during the entire time they have been using the car. Because it's so convenient! During the trip, you do not need to worry about the fact that the car can be blown off the road, for example, on ice after pressing the gas or brake pedal too sharply.

But true connoisseurs of a “clean” car, not strangled by security systems, turn off all electronic assistants in order to feel the soul and power of the car. But there are very few of them, you can even say a few.

The traction control system works only in tandem with the anti-lock system, but not vice versa. That is, the anti-lock braking system can work without anti-lock braking system, but anti-lock braking system cannot work without anti-lock braking system.

Three main types of traction control systems should be divided. They are similar, but used on different makes of cars.

Antriebsschlupfregelung (ASR) system

ASR is the most common traction control system. It is installed by such flagships of the German and world market as Mercedes, Volkswagen and Audi. The system tailored to these vehicles is a huge help for beginners who can't handle the road with confidence. The list of main features includes an instant differential lock, which makes it possible to feel a “free” or “brewed” differential. Through the differential lock is the control and adjustment of torque. electronic brain on-board computer processes the information coming from the sensors on the hubs. After an instant comparison of the speed and rotation of the drive and free wheels, the system decides to slow down, increase speed and cut off the fuel supply.

This system involves the use of three types of work. Control of the brake system of the driving wheels, engine traction control and combined, when two methods are applied at once.

The ASR system has a threshold for influencing the braking system. Usually it is 60 kilometers per hour. If this threshold is exceeded, the system will not affect the braking system in order to avoid dangerous situations. At high speeds, this system only affects the engine.

Traction control system (TCS)

This system first began to be installed on Honda cars.

The TCS system (Traction control system) is translated from English as a traction control system. This electro-hydraulic system is needed so that at the moment of sliding there is no loss of wheel-road adhesion. This system works due to sensors that read the speed and speed (revolutions per second) of each wheel. If the system detects a sharp jump in the speed (revs) of one of the drive wheels, then the traction of this wheel is turned off. The system itself will turn on the traction on this wheel after equalizing the speeds. A further variation in the number of revolutions on each wheel will be corrected by a decrease in traction.

Such a system was used, as an advanced one, for the first time on Formula 1 cars in 1990 and banned in 2008.

TRC (Traction Control) system

This security system is mainly used on expensive models of Honda and Toyota cars.

The operation of this system complements the others by preventing the car from skidding. The principle of operation of this system involves the reduction of traction and torque to prevent dangerous situations. The operation of this system is noticeable when passing dangerous turns with slippery surfaces. A car with a leading front axle, even with a sharp release of gas in a turn, thanks to this system, will not go off course. The TRC system is installed even on four-wheel drive vehicles e.g. Toyota RAV 4.

If this system works, then the driver cannot influence the movement of the car by pressing the gas pedal, because the system blocks this action.

So, modern cars stuffed with different electronic assistants and this, of course, has a positive effect on traffic situations, because thanks to such systems, there are fewer accidents due to poor grip, and drivers without driving experience in winter are not afraid of icy roads.

Video

See how TRC works with Toyota as an example:

The grip of tires with the road surface - in everyday life "derzhak" - is worth its weight in gold. Needless to say, manufacturers of equipment are going out of their way, inventing new “mulks” in order to use it most effectively. And if ABS became the “first sign”, then the modern trend is traction control, in fact, ABS is the opposite.

"Derzhak" is not infinite

Before getting into the electronic jungle of modern motorcycles, let's remember what we are fighting for. "Hold" is the maximum force applied to the wheel, at which it still clings to the asphalt, does not slip. Moreover, it is important to understand that, roughly speaking, the tire does not care which side the force is applied from, the main thing is its maximum value. In reality, forces of different nature act on the tire. Both longitudinal influences (during acceleration or braking) and transverse ones (during a turn) are trying to shift it from the trajectory. In this case, the vector sum of forces (or superposition) still remains the main one. If, for example, we want to make the most of the grip of the tires on the asphalt to counteract the centrifugal force, we will have to give up braking or accelerating in an arc. Or vice versa, you can brake as efficiently as possible only on a straight line, any turn will require its share of grip in the contact patch. But for a long time, tests have shown that the maximum “hold” on dry asphalt is achieved with a slight slip, almost on the verge of transition from rolling friction to sliding friction. It is this moment that the creators of anti-lock braking systems are trying to use for the benefit of the pilot, at the same time protecting them from skidding, that is, sliding friction. When braking, the ABS systems allow the wheel to slip into the skid for some moments, and right there - the electronics track the stop of the wheels very quickly - again allow the rubber to regain grip on the asphalt. Why not make the effect work for the benefit of overclocking? This is exactly what the Honda engineer who developed the ABS + TCS system for the 1992 ST1100 Pan European model argued. As soon as the difference in the angular speeds of rotation of the wheels (and it was measured those two decades ago through ABS sensors) exceeded a certain value, the “brain” of the engine control led the ignition to “late” (the bike was carbureted, and it was not possible to influence the composition of the mixture), and the thrust of the engine dropped sharply.

It is easy to assume that in this case the difference in the angular speeds of rotation of the wheels decreased, and as soon as it reached a reasonable - according to the "brains" - limit, the motor returned to its normal mode. But that system saved the motorcycle from active slippage during acceleration in a straight line, without saving it from lowsides if the throttle handle was carelessly handled in turns. Indeed, in a slope, it is much easier to break the wheel into slipping due to the fact that part of the “derzhak”, as we remember, is spent on counteracting centrifugal force. If the sum of the forces attributable to the contact patch of the tire with the road exceeds the friction force, the wheel will slip into the skid, and the rear of the motorcycle will wag out of the turn, putting the bike sideways to the turning path. There are three possible scenarios for the development of the situation. First, the best: the pilot did not get scared and did not close the throttle in a panic, but dropped the gas quickly, but smoothly - and the bike stabilized. The second, "continued": the pilot continued to open the gas, and in a moment the motorcycle "lay down" (lowside). The third, “brutal”: if the rider closed the throttle too late or too abruptly, the rubber instantly regains reliable grip on the asphalt, but the kinetic energy of the “wagging” movement causes the bike to jump, roll over and throw the pilot out of the saddle (highside). So here it is modern systems traction control just fight to keep the rear wheel on the verge of gripping the rubber with the road surface and come into play mainly just in corners, when the risk of putting the rear wheel into a skid is much higher than average.

How do they do it?

We note right away: there is no similarity between motorcycle and automobile traction control systems. In a world of four wheels, traction control systems not only play with engine power, but also brake individual wheels. We have only one driving wheel and engine thrust correction exclusively downwards. Motorcycle anti-axle has now become such a fashionable trend that almost all motorcycle manufacturers are actively implementing such devices, but we will list the most prominent representatives of this new breed of electronic “mules”. The first systems of the current century, designed to make the reaction to gas smoother and thereby combat the drift of the rear wheel on “civilian” vehicles, began to be used on a 2007 liter “geese”. There were no wheel speed sensors (the speedometer doesn't count) or gyroscopes, but there was a second row of stepper motor-driven throttles controlled by the brains. According to indirect parameters (motorcycle speed, selected gear, throttle position), the load on the engine was estimated, and based on these parameters, the ignition and injection system controller, depending on the selected control program (and there were three in total), limited traction, or rather, speed set engine speed under a particular load.

The “younger brothers” followed the liter - they acquired multi-mode “brains”, which are even on the current “six hundred”. The “stabilizer” on the MV Agusta F4 works on the same principle. Yes, it works, but it's too inaccurate. Without being able to track the road situation in direct parameters (the angle of the motorcycle, the speed of rotation of both wheels), this way to protect the rear wheel from demolition can only be called conditional. BMW was next in 2006 with quite a “civilian” R1200R. Here, the wheel speeds were monitored through the sensors of the ABS system, and, as in the ancient Pan-Europe, when slipping, the ignition became later, and the mixture became poorer, and the BMW ASC (Automatic Stability Control) system works much smoother and quicker. A little later, Ducati became a fighter for justice, in 2008 introducing the DTC (Ducati Traction Control) system on the 1098R model. Of course, it had little in common with a similar “stray” used in WSBK, but nevertheless, there were already speed sensors on both wheels (the signal was given by the mounting bolts brake discs), and traction correction (through a change in the ignition timing and the amount of fuel supplied) was carried out on the basis of "live" indicators obtained in real time, although also according to a template prescribed in the memory of the control system (like Suzuki and MV Agusta). Fundamental difference in that here the slip was tracked not only through a sudden increase in the crankshaft speed, but also through the speed of rotation of both wheels. The difference between “civilian” traction and racing is that serial sportbikes, unlike racing ones, do not have suspension position sensors, and in racing, few people are interested in saving gasoline, and when slipping on racing Ducati, the ignition was “cut off”. However, if this method is used on a production car with a standard exhaust, then after a couple of such anti-bux trips, the catalyst will hang on the wire from the lambda probe, so the fuel is also “chopped”, sacrificing a small loss of traction due to the “drying” of the inlet channels. The degree of "intervention" of electronics in the nature of the motor is divided into eight steps, plus the system can be turned off altogether. However, on the new Multistrada, the wheel speed is no longer read by bolts, but by ABS sensors- so much more accurate, because if you read the speed on the bolts, you get 6-8 pulses per wheel revolution (that is, 60 and 45 degrees between pulses), and if through the “comb” of the ABS induction sensor, you can get up to forty pulses in one turnover. But returning to the chronology of events, let's be honest, the BMW ASC system did not go further than the R1200R boxer naked bike, because in 2009 DTC (Dynamic Traction Control) appeared on the sensational S1000RR sportbike - a nightmare for Japanese manufacturers. It can rightfully carry the title of a masterpiece of engineering, because it contains not only these same ABS sensors, but also a gyroscope that monitors the rolls and trim of the car. It is thanks to the gyroscope on the S1000RR that it is impossible to “goof off” (of course, if the DTC system is not disabled at all), as well as to track the situation in the turn as accurately as possible (after all, if the anti-bux is reinsured and works ahead of time, then less traction can be realized, which will lead to an unnecessary loss of speed ).

For example, in the Slick mode, the engine thrust is cut by electronic throttles and nozzles, it is necessary to form a stern drift, but only when the motorcycle rolls more than 23 degrees, which implies adequately accurate gas handling. But even at the journalistic test in Portimão, many noticed that when exiting a high-speed right turn with an ascent to the finish line, the motorcycle confidently lifted front wheel into the air, despite the anti-wheeling program. BMW's electronics engineers limited themselves to vague explanations about the combination of factors (tilt-lift-acceleration) that confused the electronic "brain". In addition, from the experience of operating the editorial sports BMW we can say that the Bavarian version of the “anti-bux” still works rough, leading to scuffing on the rubber after several track sessions. Kawasaki engineers did the same on the ZX-10R Ninja, which debuted this winter (“Moto” No. 02–2011) - there, traction control carries both the charms of the BMW-shnoy DTC, and some patterns similar to those used on the previous "ninjas" (in fact, like Suzuki), which allows it to work not only in the "combat", but and in a preventive mode, stopping attempts to stall the wheel in the skid on the vine. But Yamaha decided that the Super Tén?r? a gyroscope is not needed, and was limited to the usual (by today's standards) anti-buoyancy, using only the readings of the ABS sensors. The result - as many complaints as delights.

A look into tomorrow.

In view of the increasing "electronization" of modern motorcycles, switching to electronic control chokes, as well as with the development ABS systems, I think that in a dozen years traction control will appear even on scooters. And perhaps not with induction sensors, which, as you know, start working only when a certain speed is reached (usually 15–20 km / h), but with Hall sensors, which do not care about speed (now most cars have wheel speed sensors - "halls").

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The TSC (or ASR) system got its name from the English terms Traction Control or anti-slip regulation. In Russian, this is called the traction control system. In fact, it is a secondary function of ABS. The task of the system is to prevent the wheels from slipping on slippery surfaces. When starting the car from a place or a sharp gas supply on the go. As practice shows, a sufficiently powerful car is able to turn the wheels in both second and third gear on the go if the wrong tires are selected or the asphalt is wet.

How does the system work?

In the event that wheel speed sensors register slip, the system, depending on the settings, can reduce fuel supply and reduce engine torque, either slow down the slipping wheel, or do both at the same time. The system is especially useful on slippery surfaces. It is also able to prevent wheel slippage when adding gas in turns, thereby preventing skidding. rear axle on rear-wheel drive cars and demolition of the front on front-wheel drive. The system also helps when starting on a slippery surface uphill, a visual demonstration on the video.

Story

The first samples of the system appeared in Europe on the Mercedes-Benz S-Class in 1987, and earlier in the USA, on Buick cars in 1971 and Cadillac in 1979. For a long time it was an exclusive option for expensive and powerful cars, but now it is widely used as part of ESP systems.

Advantages and disadvantages

The system has a positive effect on the stability and safety of the car, especially on slippery surfaces, preventing the driver from causing a critical situation by excessively pressing the gas. But it can do a disservice when driving through deep snow, sand or mud, “choking” the engine just at the moment when the car needs maximum gas to slip out of unstable coverage. Therefore, if you need to drive through sand or snow (at low speed), Traction Control should be turned off in advance.