What is the working process of the car ABS system?
2 Answers
ABS system working process: During braking, the ABS quickly determines the wheel lock-up state based on the speed signals from each wheel speed sensor. It closes the normally open input solenoid valve for the wheel that begins to lock up, keeping the braking force constant. If the wheel continues to lock up, the normally closed output solenoid valve is opened, causing the braking pressure on that wheel to rapidly decrease due to the direct connection to the brake fluid reservoir, preventing the wheel from completely locking up due to excessive braking force. This ensures the braking state remains at the optimal point (slip rate S of 20%), achieving the best braking effect and maximum driving safety. Functions of ABS: Maximize the effectiveness of the brakes, reducing braking time and distance. Effectively prevent vehicle skidding and fishtailing during emergency braking, ensuring good driving stability. Allow steering during emergency braking, providing good steering control. Avoid intense friction between the tires and the ground, reducing tire wear.
I remember one rainy day when I almost rear-ended another car, and it was the ABS that saved me. This system is like an intelligent braking butler, capable of acting dozens of times per second. When you slam on the brakes, the wheel speed sensors immediately start monitoring the rotation speed of all four wheels. If they detect that one wheel is rotating significantly slower than the others, the controller knows it's about to lock up. At that moment, the solenoid valve quickly adjusts the brake fluid pressure in the line, slightly releasing the brake on the locking wheel. Once the wheel starts rotating again, the system immediately reapplies pressure, cycling between release and application repeatedly. Throughout this process, the tires remain in a state of near-lockup, maintaining maximum friction for deceleration while still allowing you to steer and avoid danger. Nowadays, most cars come standard with this feature, which can prevent loss of control in critical moments.
