Today in the world of automobiles, many electronic systems and assistants are practiced that work to increase active and passive safety. Thus, electronics can prevent accidents that occur when the car is moving. Now all vehicles are necessarily equipped with such a system as ABS. But this is far from the only system in the base list. So, models with a class higher are equipped with ASR. What it is? This is a traction control system. We will consider the principle of its operation and advantages further.
Characteristic
So what is an ASR? This is an element of active car safety. The action of ASR is aimed at maintaining the contact of the wheels of the vehicle with the road while driving.
In common people, this system is called "antibuks." The official name is the automatic slip control system. Thus, the operation of the traction control system is aimed at protecting the driving pair of wheels from slipping on a wet or icy surface, as well as during a sharp start from a place or during other dangerous maneuvers.
About abbreviation
It is worth noting that ASR is not the only abbreviation that designates this system. So, on Volvo cars it is marked as STC, on Toyota TRC (Traction Control), on Opel DSA, on Range Rovers ETC. However, in most cases, this system can be recognized by the first marking. What is noteworthy, it acts the same on all cars. Therefore, it cannot be said that ASR at Volkswagen is worse than at Audi and Mercedes, and vice versa. On any vehicle, it performs the function of maintaining the vehicle’s dynamic course and works closely with the anti-lock wheel system.
Operating principle
ASR always works, regardless of the current speed of the car. However, its functionality is slightly different:
- At a speed of 0 to 80 kilometers per hour, the system transmits torque thanks to the braking of the drive wheels of the car.
- At speeds above 80 kilometers per hour, the forces are regulated by reducing the torque that is transmitted from the engine.
The traction control system operates based on signals from different sensors:
As a result, the control unit determines the following characteristics:
- Vehicle speed. The data are based on the angular velocity of the wheels on a non-driving axle.
- The angular acceleration of the drive wheels.
- Type of machine movement. Distinguish curvilinear and rectilinear movement of the car.
- The amount of slippage of the drive wheels. Information is obtained based on the difference in the angular velocity of the wheels on the driving and driven axles.
Depending on the received data, the electronics either control the brake pressure or act on the engine itself, reducing its torque.
If we talk about the first case, brake pressure control is carried out cyclically. So, in a cycle there are several phases:
- Magnification.
- Retention.
- Depressurization
The increase in hydraulic fluid pressure contributes to the braking of the drive wheels. This is due to the inclusion of a reverse feed pump. This opens the high pressure valve and closes the switch. Due to the return pump, this pressure is maintained. A reset is performed after slipping. At the same time, the inlet and switching valves are included in the operation. This cycle can be repeated several times, depending on the current traffic situation.
But torque control is a little different. This process is carried out with the use of the engine control system. Based on the received signals from the sensors of the angular velocity of the wheels and the actual torque (which is measured by the computer), the ASR control unit calculates how much it is necessary to reduce the power of the power unit. This information is transmitted to the electronic engine control unit. But how is this data implemented? The ASR system reduces power and torque in several ways:
- When changing the position of the throttle (it closes more than it should).
- The fuel injection passes in the system.
- The misfiring pulses.
- When canceling gear shifting. But this is only possible with an automatic transmission.
- When changing the ignition timing.
How does the driver understand that the ASR system is operational?
The driver will be informed about this by a special warning lamp on the instrument panel. At the end of the system and when the vehicle exits slipping, this lamp disappears. The engine and brake system work as usual.
Benefits of using
This system is installed on cars for a reason. She really benefits. The main advantage of having an ASR is its increased traffic safety. The driver is not immune from mistakes. However, electronics are able to correct them and prevent the car from skidding, which could lead to an accident. Also, the ASR traction control system allows you to extend the life of the engine, since the torque is distributed more smoothly. Another advantage of this system is less tire abrasion, which could have occurred in the event of unauthorized slipping. In addition, ASR has a positive effect on fuel consumption, albeit slightly.
How to disable traction control?
If desired, any driver can forcibly disable ASR. For this, a special button is provided in the machine.
After turning off the traction control system, the machine will enter into turns with a sliding drive axle. In this case, in case of braking , the ABS system will still work. Also on the instrument panel, the corresponding lamp will light up. It is a yellow flashing triangle with an exclamation mark. It lights up when the wheels slip. And no matter what the current speed is 5 or 100 kilometers per hour.
In what cases is it recommended to forcibly turn off the traction control system? This must be done in winter if it is impossible to move off in the snow or on an icy surface. After leaving a difficult area, the manufacturer recommends re-enabling the ASR traction control system. The yellow indicator on the panel will turn off.
Conclusion
So, we found out how the traction control system works and why it is needed. As you can see, ASR is designed to increase vehicle safety in difficult conditions, eliminating the possibility of slipping and skidding of a vehicle. However, no matter how smart the system, it does not give 100 percent protection. Therefore, you should always rely only on your driving skills and speed of reaction.