What is the principle of the ABS system?
2 Answers
The principle of the ABS system is: during braking, the ABS quickly determines the wheel lock-up state based on the speed signals from each wheel speed sensor, closes the normally open input solenoid valve on the wheel that is beginning to lock, and keeps the braking force constant. If the wheel continues to lock, the normally closed output solenoid valve is opened, and the braking pressure on that wheel rapidly decreases due to the direct connection to the brake fluid reservoir, preventing the wheel from completely locking due to excessive braking force. The functions of ABS are: 1. Maximize the effectiveness of the brakes, reducing braking time and distance; 2. Effectively prevent vehicle skidding and fishtailing during emergency braking, ensuring good driving stability; 3. Allow steering during emergency braking, providing good steering control; 4. Avoid severe friction between the tires and the ground, reducing tire wear.
I'm very interested in automotive technology. The ABS system, called the Anti-lock Braking System, works by electronically preventing wheel lock-up during emergency braking. There are speed sensors on the wheels that monitor wheel speed in real-time, and the data is transmitted to a computer unit called the ECU. When the ECU detects that a wheel is about to lock, it commands the hydraulic modulator to rapidly switch brake pressure—releasing and reapplying brake fluid dozens of times per second, effectively performing automatic cadence braking. This keeps the wheels slightly rotating, preventing skidding and loss of control, allowing you to steer around obstacles even while braking hard. ABS was first introduced in vehicles in the 1970s and is a fundamental active safety feature that significantly reduces braking distances on slippery surfaces. In daily driving, if you feel the brake pedal pulsating, that's the ABS working—no need to worry. The system requires regular maintenance, such as cleaning sensors or checking the hydraulic pump, otherwise, it may fail in winter, compromising handling safety.
