ASR - Acceleration Slip Control

ASR stands for Acceleration Slip Control and is an optional extra to ABS to control the vehicle's slip during acceleration.

The system, which is part of the traction control methods, ensures that the wheels do not slip during acceleration: an attempt to lose traction is detected by the ABS sensors and is prevented by the combined action of the brake calipers. engine power supply.

Obviously, this is useful in critical conditions (rain or ice) to avoid loss of control caused by changes in road surface conditions: on the contrary, in competition these systems guarantee a noticeable improvement in performance caused by constant traction control. conditions that allow the pilot to control the acceleration phase not with manual control, but with an electronic control unit that optimizes its performance (technically, the system is called drive-by-wire).

The system has disadvantages when driving on loose terrain, such as mud, snow or sand, or on ground with poor traction. In this situation, when you try to drive away, the drive wheels slip from the very first moments due to poor traction: but the system blocks them from slipping, preventing or greatly impeding the movement of the car itself. On this type of terrain, traction is provided more by wheel slip than by its adhesion to the road surface (in this case, the grooves and blocks of the tire act as "grip", and on asphalt, the rubber coating. - regardless of tessellation - which gives "clutch"). The most advanced systems, such as those found on today's SUVs, contain sensors to "interpret" the type of surface or provide the ability to bypass the system.

ASR is very useful when only one of the driving wheels is losing traction: in this case, the differential will transmit all the torque to that wheel, preventing the car from moving. The anti-skid system blocks the wheel's freedom of movement, allowing the differential to maintain torque at the wheel that is still traction. This result is also achieved through the use of a limited slip differential. ASR is more efficient because it interacts “intelligently” with other electronic devices and with the engine itself, while the limited slip differential is a “passive” mechanism.

In the constant search for more vehicle safety, more and more production vehicles are equipped with this system, which at first was the prerogative of more sporty and expensive models.

Its abbreviation literally means: slip control during acceleration. So how easy is it to understand how it works and is completely analogous to TCS.