What is the ABS system in a car?

[NadiaRose]

ABS, short for Antilock Brake System, is designed to automatically control the braking force during vehicle braking, preventing the wheels from locking up. It maintains the wheels in a state of rolling and sliding (with a slip ratio of around 20%) to ensure maximum adhesion between the tires and the road surface. How ABS works: During braking, ABS quickly determines the wheel lock-up status based on speed signals from each wheel speed sensor. It closes the normally open input solenoid valve for the wheel that begins to lock, keeping the braking force constant. If the wheel continues to lock, the normally closed output solenoid valve opens, rapidly reducing the braking pressure on that wheel by diverting brake fluid directly to the reservoir. This prevents the wheel from fully locking due to excessive braking force. The system maintains the braking state at the optimal point (with a slip ratio S of 20%), achieving the best braking performance and ensuring driving safety. Functions of ABS: It maximizes the effectiveness of the brakes, shortening braking time and distance. It effectively prevents vehicle skidding and fishtailing during emergency braking, ensuring good driving stability. It allows steering during emergency braking, providing excellent steering control. It avoids severe friction between the tires and the road surface, reducing tire wear.

[StAshley]

Just the other day I was helping my neighbor check their brake issue and happened to research ABS. Simply put, it's a system that prevents wheels from locking up during hard braking. When you suddenly slam on the brakes, ABS uses computer-controlled brake fluid pressure to keep the wheels rolling while braking. It's like doing rapid taps on bicycle brakes when we were kids - much safer than full lockup. The key benefit is maintaining steering control. I once triggered ABS on a rainy day and could still steer to avoid an e-bike. The mechanic said most cars over 10 years old now come with this system, and if the ABS warning light comes on, you should immediately check the sensors or wiring.

[VanDaniela]

Having driven for 20 years, my most direct experience is that ABS prevents loss of control during emergency braking. Two years ago during heavy snow on the highway, I encountered a rear-end collision and instinctively stomped on the brake pedal. I distinctly felt the pedal rapidly pulsing under my foot, and the car made a clicking sound like hiccups. The wheels didn't lock up, allowing me to change lanes to avoid the collision, with only a slight skid. Later, I learned from the 4S dealership that ABS can pulse the brakes over a dozen times per second, more stable than even an experienced driver's footwork. For daily maintenance, it's crucial to prevent deep grooves on the brake discs and ensure tire treads aren't worn flat, as ABS can fail under these conditions—details every seasoned driver knows well.

[OAdrian]

Studying the ABS principle is quite fascinating. The core lies in the speed sensors on all four wheels, with the onboard computer constantly comparing the rotational speed differences. Whenever a wheel's speed changes abruptly, the computer immediately commands the hydraulic modulator to reduce pressure. It sounds complex, but the effect is straightforward—last year, when I drove an old car without ABS through a puddle and hit the brakes, the car slid sideways for three to four meters. In the same situation with a new ABS-equipped car, it just shuddered and slowed down with a rhythmic 'clunk-clunk.' New drivers should get used to that pulsating brake pedal sensation and avoid panicking and releasing the brakes.