The function and principle of anti lock brake system

"Anti lock braking system" is translated into Chinese as "anti lock braking system". It is an auxiliary technology of conventional brake device, which can be divided into mechanical type and electronic type. It enables the braking system to have the braking function, at the same time, it can prevent the wheels from locking, make the car still turn in the braking state, ensure the stability of the braking direction of the car, and prevent the side slip and deviation.

The first ABS in the world came out in 1950. It was first applied to aircraft in the field of aviation, and began to be applied to automobiles in 1968. Now, ABS has been the basic safety equipment of general models.

When braking on emergency braking or low adhesion road such as ice and snow road, the rolling wheels tend to slip and lock up because the braking force exceeds the maximum adhesion provided by the road. After wheel locking, it will lose the lateral adhesion ability and cannot bear the lateral force. Generally, the front wheel locking will cause the car to lose the steering ability, and the rear wheel locking will cause the car to lose its tail and stability.

At this time, ABS can calculate the vehicle speed, wheel angle deceleration and wheel slip ratio according to the wheel angle speed signals. According to the above information, ABS reduces the braking force when the wheel tends to lock, maintains the braking force when the wheel angle deceleration or slip ratio is in a certain range, and recovers the driving force when the wheel speed increases. As the action is very fast, it seems that the brake is slightly released. When the ABS system is applied to the car, the brake pedal will vibrate up and down. But this is a normal phenomenon.

In case of emergency, the driver usually steps on the brake hard. If there is no ABS to control the brake action, the tire will lock up and slip because the brake force is too large. Generally speaking, the reaction ability of driving is not enough to control the braking force correctly, but ABS has the ability to control the braking action of each wheel, making it close to idealization. ABS is not only to shorten the braking distance of the vehicle, but even to increase the braking distance in some cases. Its main purpose is to make the vehicle in motion completely under control in the braking process, and not to lose control of the vehicle due to the tire locking.

In the ordinary asphalt pavement, especially in the case of wet and slippery road, ABS can significantly improve the braking action of vehicles and shorten the braking distance. On soft roads, such as sand and snow, ABS will significantly increase the braking distance. Because in this case, the locked wheel will squeeze the road surface and form a bump, and then fall into the soil pile, and vehicles using ABS can easily cross and reduce such a bump. This allows ABS controlled vehicles to move faster in the field or snow. ABS can enhance the maneuverability of the vehicle in various situations, and the general driving can still bypass the obstacles in the process of emergency braking, which is almost impossible for the general driving without ABS, thus greatly improving the driving safety.