What does ABS mean and what is its function in a car?
2 Answers
ABS, short for Anti-lock Braking System, functions by automatically controlling the braking force during vehicle braking to prevent wheel lock-up. It maintains the wheels in a state of rolling and sliding (with a slip ratio of around 20%), ensuring maximum traction between the tires and the road. The ABS sensor is located on the inner side of the car's tires and can be seen when the vehicle is lifted. The ABS system mainly consists of four components: wheel speed sensors, the electronic control unit (ECU), the hydraulic unit, and the ABS warning light. The wheel speed sensors detect the motion state of the wheels and generate sinusoidal electronic pulse signals. These signals are then processed by a modulator, converted into digital signals, and transmitted to the electronic control unit. The electronic central control unit (ECU) receives input signals from the wheel speed sensors, calculates the wheel speed, vehicle speed, and slip ratio based on these parameters, and determines the wheel's condition. It then sends control commands to the hydraulic unit. The hydraulic unit adjusts the pressure in the brake lines according to the control commands, with the adjustment process including pressure maintenance, pressure increase, and pressure decrease. The ABS warning light alerts the driver to any system malfunctions. If the ABS warning light is on, it is advisable not to continue driving. This is because the illuminated ABS light indicates a malfunction in the vehicle's anti-lock braking system. During emergency braking, if the wheels lock up, the vehicle may skid uncontrollably, making it difficult for the driver to decelerate or adjust the vehicle's trajectory, posing significant safety risks.
My first encounter with ABS was on a rainy urban expressway when a car suddenly changed lanes in front of me. I slammed on the brakes and felt a clicking vibration under my foot, yet the steering wheel remained responsive, and the car came to a stable stop without skidding. So this was the anti-lock braking system in action! Its full name is Anti-lock Braking System, which essentially prevents wheels from completely locking up during hard braking, maintaining slight tire rotation. This not only shortens braking distance but also allows steering control—especially useful in rain or snow. Nowadays, 90% of new cars come equipped with this feature as production costs have significantly decreased. Though some veteran drivers complain about ABS's springy pedal feedback, it's just a matter of getting used to it. What truly matters is its life-saving capability in critical moments.
