What role does the ABS system play when a vehicle performs emergency braking?
2 Answers
The role of the ABS system during emergency braking in a vehicle includes fully utilizing the effectiveness of the brakes, reducing braking time and distance; effectively preventing vehicle skidding and fishtailing during emergency braking, ensuring good driving stability; enabling steering during emergency braking, providing excellent steering control; and avoiding intense friction between the tires and the ground, reducing tire wear. How ABS works: 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 for the wheel that is starting 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 keeps the braking state at the optimal point (slip ratio S of 20%), achieving the best braking effect and the highest driving safety.
Back when I drove that old car without ABS, I almost rear-ended someone during emergency braking in the rain—the steering wheel was completely locked up. ABS is specifically designed to solve this problem. When you slam on the brakes, it detects if a wheel is about to lock up using wheel speed sensors and instantly releases and reapplies brake pressure via a pump, doing this over a dozen times per second. This keeps the tires right at the edge of locking, preventing skidding while maintaining steering control. I’ve tested ABS-equipped cars in snow—even with full braking, you can still steer around obstacles, and the stopping distance is actually shorter than with manual cadence braking. The key is the system reacts hundreds of times faster than a human, especially on slippery roads—it can be a lifesaver. Nowadays, driver’s ed even teaches proper ABS usage.
