Introduction
When driving rain, environmental influences, the brake disc surface will form a water film, if not promptly cleared, which may result in the driver when the brake pedal is depressed, the contact of the brake pads and the brake disc is insufficient, so that the braking force is decreased, so that the brake is delayed, the braking distance becomes longer result. In addition to this water feature it seems not worth mentioning, but to restore a few meters braking distance that sometimes you might just avoid significant losses.
In fact, to achieve this functionality without having to modify the structure of the brake drastic, just rely on tire pressure monitoring wheel speed to achieve the same, BSW brake disc water film Clear also is the only one program ESP control unit only, I know, make you curious as to how the system determines that the water film appears on the brake disc?
will do the tops of the brake disc a rain sensor? This problem seems complicated, in fact, determine the logic is very simple, function is activated need to meet two conditions, one is speed, as this function is mainly to help improve security during high-speed driving, therefore, need to meet the speed 70 km / a vehicle speed condition, another condition hours wiper is turned on, the system to judge the degree of adhesion of the water film on the brake disk wiper based on time. When the above conditions are satisfied, ESP system will be applied every 5 minutes for the brake line pressure of 3bar (full braking pressure to stop the vehicle 30bar), to allow the water film on the brake pads the brake disc wipe (probably rub ring 15), the whole process does not interfere with the driver. This feature does not cause significant brake disc wear.