The traction control system is a set of mechanisms and electronic components of a car that are designed to prevent slippage of the drive wheels. The TCS system (Traction Control System, traction control system) is the trade name for the traction control system that is installed on Honda cars. Similar systems are installed on cars of other brands, but they have different trade names: TRC traction control system (Toyota), ASR traction control system (Audi, Mercedes, Volkswagen), ETC system ( range rover) and others.
Activated TCS prevents the vehicle's drive wheels from slipping when starting off, hard acceleration, cornering, bad road conditions and rapid restructuring. Consider the principle of operation of TCS, its components and general device, as well as the pros and cons of its operation.
How TCS works
The principle of operation of the traction control systemThe general principle of operation of the Traction Control System is quite simple: the sensors that make up the system record the position of the wheels, their angular velocity and the degree of slippage. As soon as one of the wheels begins to spin, TCS immediately eliminates the loss of traction with pavement.
The traction control system copes with slippage in the following ways:
- Braking of slipping wheels. The brake system is activated at low speeds - up to 80 km / h.
- Reducing the torque of the car engine. At speeds above 80 km/h, the engine management system is activated, which changes the amount of torque.
- A combination of the first two methods.
Note that the Traction Control System is installed on cars with (ABS - Antilock Brake System). Both systems use the readings of the same sensors in their work, both systems aim to provide the wheels with maximum grip on the ground. The main difference is that ABS limits the braking of the wheels, while TCS, on the contrary, slows down a rapidly spinning wheel.
Device and main components
Diagram of the ABS+TCS system Traction Control System is based on elements of the anti-lock braking system. The wheel slip prevention system uses as well as the engine torque control system. The main components necessary to implement the functions of the TCS traction control system:
- Feed pump brake fluid. This component creates pressure in brake system car.
- Switching solenoid valve and high pressure solenoid valve. Each drive wheel is equipped with such valves. These components control braking within a given circuit. Both valves are part of the ABS hydraulic block.
- ABS/TCS control unit. Controls the traction control system using the built-in software.
- The engine control unit. Interacts with the ABS/TCS control unit. The traction control system connects it to work if the speed of the car is more than 80 km / h. The engine management system receives data from sensors and sends control signals to actuators.
- Wheel speed sensors. Each wheel of the machine is equipped with this sensor. The sensors register the speed of rotation, and then transmit signals to the ABS / TCS control unit.
TCS enable/disable button Note that the driver can turn off the traction control system. Usually on dashboard there is a "TCS" button that turns the system on/off. Disabling TCS is accompanied by the illumination of the "TCS Off" indicator on the instrument panel. If there is no such button, then the traction control system can be turned off by pulling out the appropriate fuse. However, this is not recommended.
Advantages and disadvantages
Main advantages of Traction Control System:
- confident start of the car from a place on any road surface;
- vehicle stability when cornering;
- traffic safety in various weather conditions (ice, wet canvas, snow);
- decrease .
Note that in some driving modes, the traction control system reduces engine performance, and also does not allow you to fully control the behavior of the car on the road.
Application
The TCS traction control system is installed on cars Japanese brand Honda. Similar systems are installed on cars of other automakers, and the difference in trade names is explained by the fact that each automaker, independently of the others, developed an anti-slip system for its own needs.
The widespread use of this system has made it possible to significantly increase the level of vehicle safety when driving due to continuous control of adhesion to the road surface and improved handling when accelerating.
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 the wheel speed sensors register slippage, 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.
History
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.
Traction control - what is it? Not every experienced motorist can easily and quickly answer this question. Nevertheless, this system, firmly established under different names in cars of various brands, is considered one of the most effective means active safety, with which manufacturers associate a number of hopes in the field of reducing accidents on the roads.
We will try to understand what modern traction control is and understand how effective it really is.
ASR / Traction Control - what is it
So, let's understand what is traction control? In simple terms, this is a system that includes a clutch that redistributes torque between the driving wheels of the car, an anti-lock system that selectively brakes the wheels, as well as a set of sensors with a control unit that coordinates the actions of these devices to dampen the vehicle skid and wheel slip.
In fact, today traction control combines the capabilities of anti-skid and traction control systems, although it was originally created as an effective tool to combat slip.
It is a well-known fact that the first car brand to commercially introduce traction control in cars was American company Buick introduced a system called MaxTrac in 1971.
The operation of the system was focused on preventing the slipping of the drive wheels, and the control unit, using sensors, determined the slip and gave a signal to reduce the engine speed by interrupting the ignition in one or more cylinders, that is, “strangled” the motor.
This scheme turned out to be very tenacious and is now used by almost all automakers. However, at that time, the traction control system did not have the function of dynamic stabilization of the car.
A significant role in the development of the Traction Control system (abbreviated as TRC) was made by the Japanese engineers of the Toyota concern. It was they who were one of the first who came up with the idea to use the principles embedded in the system to stabilize the car in the event of an emergency.
Video - Toyota tells how traction control works:
The difference between TRC and Toyota was an integrated approach to the design of the system, which included angular velocity sensors in the wheels of the car, tracking the speed of rotation of each of the wheels, as well as the use of complex methods for reducing traction.
In the first versions cars traction was also reduced by “suffocating” the motor, and in modern versions of the system installed on (for example, the popular Toyota RAV-4), a selective reduction in the speed of rotation of one or another wheel is carried out using a standard viscous coupling, which receives signals from the central unit system control.
At the same time, the viscous coupling does not reduce the moment on the slipping wheel, but proportionally increases the amount of torque on the wheel that has better grip. In such a “powerful” way, the car returns to the required trajectory and there is no danger of skidding, but in the opposite direction from the slippery surface.
Advantages and Disadvantages of Modern Traction Control Systems
Modern traction control systems have a number of advantages and disadvantages. The first, of course, include greater driving safety, because the system itself is able to “recognize” the risk of skidding and extinguish its development.
On the other hand, such "assistance" relaxes the driver, which can lead to less caution when driving on slippery surfaces. In addition, do not forget about situations where wheel slip is not evil, but, on the contrary, can be a driver's assistant.
By the way, this statement does not apply at all to lovers of drifting and high-speed driving on race tracks, but to those drivers who often drive off-road or in deep snow. For example, anti-skid and anti-skid systems can play a cruel joke if you decide to overcome the “pull-in” virgin snow.
By artificially limiting the speed, the system is able to turn off the car's engine at the most crucial moment, and such a "gift" will end in the search for a tractor. To avoid such unpleasant situations, it is practically possible to turn off the traction control, for which a separate key on the center console of the car is used.
As a rule, the corresponding designation is applied to it (on the same Toyota crossovers it is “TRC off”). Using the key, you can deactivate the system in order to successfully overcome a difficult area.
Using traction control in real operation
Despite the fact that many modern cars have the option of traction control, not all drivers know how to use this system. Let's try to figure out how to use the traction control system with an example Toyota car RAV-4.
In normal driving mode, so to speak, "by default", the TRC system on Toyota is constantly activated. Her intervention in control is completely imperceptible at first glance, however, when one or more wheels of the car hit a slippery section of the road, the system comes into action, “directing” the car in the right direction and preventing the development of a skid.
In practice, this can be seen in the selective operation of the anti-lock braking system, which is accompanied by a characteristic crunch, as well as a decreasing reaction to the gas pedal. In addition, the corresponding indicator flashes on the dashboard, signaling that the system has been triggered.
In Toyota TRC OFF cars - what is this button and how to use it
In order to turn off the stabilization system, as already mentioned, the driver will need to press the button labeled "TRC off" on the center console of your Toyota. This should be done as consciously as possible - only if wheel slip is really a necessary condition.
In addition to the above-mentioned off-road driving, it makes sense to turn off traction control also in cases where intensive acceleration of the car is necessary (for example, to overcome difficult sections on the road.
It is worth mentioning separately the fact that in the Toyota crossover TRC is not completely turned off, that is, pressing the “TRC off” key only briefly deactivates the system. In addition, the system automatically turns on when a speed of 40 kilometers per hour is reached, as indicated by the inscription "TRC on" on the dashboard.
Accordingly, if it is necessary to turn off again, the button will have to be pressed again. Such a precaution of the manufacturer is justified by safety standards, since today it is traction control that is considered one of the most effective security systems.
As a matter of fact, this statement is supported by the statistics of road traffic accidents in different countries, and many independent organizations are lobbying for the introduction of legislative standards that oblige the use of TRC systems on all cars sold on the market, regardless of the configuration.
Results
As you can see, traction control is a really easy-to-use safety system that makes life easier for the driver. The forced shutdown feature avoids situations where the operation of the TRC could adversely affect driving.
However, any electronics is only an assistant, in no way a guarantee of safety. Only the driver himself can make the ride truly trouble-free and competent.
We analyze the so-called or when to change tires.
Hai! All kinds of know-how of the world of two-, three-wheeled vehicles get into the "Biker's Dictionary" of the site not only. In the section "Moto news" you will be able to find a lot of fresh information.
TCS or Traction control system of the motorcycle is an electronic system for the timely prevention of complete or partial loss of wheel traction with the road surface due to the hydraulic control of the bike slipping process.
It not only greatly simplifies the management of the iron horse on wet and sandy sections of the road, but also prevents from time to time a loss of speed, as well as a fall of the motorcyclist.
Thanks to special sensors in real time automatic system monitors wheel speed. Having detected a clear start of the slipping process, the system automatically reduces such torque.
TCS is widely used in motorcycle racing. She equipped the bikes of most sports on the planet. The Traction control system works quite interestingly, using a variety of methods to reduce wheel speed. So, the sparking process can automatically stop at least in one of the cylinders. In addition, the above effect is often achieved by reducing the amount of fuel supplied to the cylinders. The most effective cover electronic system throttle valve or a timely change in the ignition timing of the fuel mixture.
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 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 from low-sides when handling the throttle handle carelessly in corners. 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 pilot has closed the throttle too late or too abruptly, the rubber instantly regains a reliable grip on the asphalt, but the kinetic energy of the "waggling" movement causes the bike to jump, roll over and throw the pilot out of the saddle (highside). So, modern traction control systems are just struggling to keep the rear wheel on the verge of rubber adhesion to the road surface and come into play mainly just in corners, when there is a risk of letting rear wheel in a skid well above 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 drive wheel and the engine thrust correction is exclusively downward. 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 (speedometer does not count), no gyroscopes, but there was a second row throttle valves driven by a stepper motor, controlled by "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 of them in total), limited traction, or rather, speed set engine speed under a particular load.
The “little 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. Not 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 brake disc mounting bolts), and traction correction (by changing the ignition timing and the amount of fuel supplied ) was made on the basis of "live" indicators obtained in real time, although also according to the template prescribed in the memory of the control system (as in Suzuki and MV Agusta). The fundamental difference is 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. What distinguishes “civilian” traction from 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 regular 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 “drying out” 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 from ABS sensors - this is much more accurate, because if you read the speed by 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, then you can get up to forty pulses per revolution. But returning to the chronology of events, let's be honest, the BMW ASC system did not go further than the boxer naked R1200R, 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 an engineering masterpiece, 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 “go overboard” (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 drift of the stern, but only when the bike 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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