What is the Acceleration Slip Regulation (ASR)and its advantages and disadvantages

What is the Acceleration Slip Regulation (ASR)and its advantages and disadvantages Traction control (from traction control system, TCS), also called anti-skid or anti spin (from Anti-Slip Anti-Spin or ASR) is an electronic management system, which prevents the drive wheel slip of a vehicle during acceleration and, especially for motorcycles, it can also be used as a system antiimpennamento (from Anti weeling).

These devices, which appeared in the second half of the eighties, have had a big spread in the course of the next decade. Currently, all manufacturers offer them as standard or as an accessory across the range. Despite being born to two-wheel drive (to improve traction and reduce understeer in a front-wheel drive vehicles during acceleration when cornering, while the means to reduce rear-wheel drive oversteer), today is also used on passenger cars to four wheel drive by assisting the action ripartitrice differentials in ensuring adherence to the wheels.

This system detects wheelspin through sensors placed on all wheels and, thanks to a computer which processes the acquired data on some variables involved, which are different depending on the type of system control.

The various systems may use different solutions to control the power, which can be used individually or together

Most differential fitted as standard on cars are characterized by a major limitation: when a drive wheel slide, turning on the vacuum, such as on slippery surfaces, since all the torque of the motor goes to this wheel, but what has a minimum friction is not receiving power and thus the vehicle is stationary. To overcome this problem, the traction control unit, receiving additional data on the wheel that has lost grip even by the ABS control unit, which slows the tire flap redistributing torque to the wheel with more grip and allowing the vehicle's progress. Logically, the unit operates in this way only to allow a vehicle to regain traction remained bogged down and then move forward. In fact if the system was adopted for reducing the drive wheel slip when the vehicle is in strong acceleration on a straight road or when the vehicle is already in motion, it would create important differences in the speed of rotation of the tires of the two axes that lead to an involuntary change of trajectory and loss of control.

As soon as the drive wheels slip, the controller of the traction control intervenes Food slightly reduces the engine power output. Therefore, being removed from the drive wheels only pair that determines the excess slip, the tires are able to exploit, without slipping, across the grip offered at that time from the road surface, consequently determining the maximum acceleration of the vehicle. Remember about a very important principle of physics, who says that has more grip an object that moves on a surface rather than an object being dragged. This type of traction control is particularly suitable for cars with high power and torque and can be modulated with a particular by-wire throttle control (drive by wire).

This technology was used primarily on competition motorcycles, Class 500, almost never accompanied by other control systems for difficult to apply and / or less safe (being powered vehicles with a carburetor is more expensive and complicated to control the power through power.) This system, once recognized the need to reduce the energy transmitted, delays the ignition of the engine size or one or more cylinders. In 2008, some large-displacement motorcycles (1000) have used a sports setting such system.

The traction control is evidently useful in: critical conditions (rain or ice) to prevent loss of control caused by a change of road conditions: vice versa, in competitions such systems provide an improvement and advantage of the benefits generated by a management continued adherence to the conditions of allowing the rider not to have to manage the acceleration phase by manual control, but through an electronic device that optimizes performance (the system is technically referred to as drive by wire). loss of traction of a wheel, in this case, the differential would transfer all the torque on the wheel, preventing the movement of the car. The WSP block the freedom of the wheel, allowing the differential to keep the torque on the wheel that still has grip. This result is also achieved by adopting a limited slip differential.

The system has disadvantages when you: transit on land not compact, such as clay, sand or snow or soft ground: in this situation, when you try to leave, the drive wheels slip from the earliest moments, due to poor adhesion, but the system will lock the slip preventing or hindering their heavily, the very movement of the vehicle. Soils of this type, the wheel slip during the early stages of acceleration can compact the soil next to the tire, which ensures a better grip. The more advanced systems, like those fitted on modern off-road sensors to provide "interpret" the type of fund, or provide for the possibility of excluding the system. difficulties in the use of controlled skidding: you can not easily implement this technique because it becomes impossible to skid the wheels. This can be disadvantageous in sporty driving on auto but powerful this system is often controlled or excluded. Most of the cars allows you to temporarily disable the TCS with the appropriate button.

In the ongoing search for greater vehicle safety, more and more cars are equipped with the series, which initially was the prerogative of the more expensive sports. In 2008 appeared the first motorcycle that use this type of control. Obviously it is a less invasive than the equivalent automotive and motorcycle applications to sports, where it is equipped with various controls.