What is the basic working principle of ABS?
3 Answers
ABS basically works as follows: during braking, 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 starting to lock up, and keeps the braking force unchanged. If the wheel continues to lock up, the normally closed output solenoid valve is opened. The advantages of the ABS anti-lock braking system are: it can prevent loss of steering control and wheel skidding during emergency braking, prevent the wheels from being locked during braking, avoid the tires from rubbing against the ground at a single point, thereby increasing friction, achieving a braking efficiency of over 90%, reducing brake wear, and extending the service life of brake drums, discs, and tires.
Once when I was driving and slammed on the brakes on snow, I felt the brake pedal pulsating—that was the ABS in action. ABS stands for Anti-lock Braking System, and its basic working principle is actually quite simple: when the system sensors detect that a wheel is about to lock up, it momentarily releases some brake pressure to keep the wheel rotating, then quickly reapplies braking force. This adjustment can repeat 15-20 times per second, somewhat like manual pumping of the brakes but far more efficient. Sensors are installed on each wheel to detect speed differences in real time. Once an abnormal signal is detected, the control unit intervenes to adjust. The key point is to prevent loss of control and skidding—for example, on slippery roads, you can still steer to avoid obstacles, significantly reducing the risk of a collision. I find this technology very practical. After buying a car, I make sure to regularly check if the sensors are covered in dust to ensure they respond promptly in emergencies.
As a car maintenance enthusiast, I often ponder how ABS works. The core principle is that sensors monitor the speed changes of each wheel. If a wheel is about to lock up during hard braking, the electronic control unit rapidly opens and closes the hydraulic valves to modulate the braking force. This high-frequency release and reapplication of braking prevents wheel lockup, allowing the driver to maintain steering control and effectively avoid obstacles. ABS is particularly useful on rainy days or gravel roads where tire grip is reduced, as the system can prevent skidding. I recommend familiarizing yourself with the pedal pulsation sensation during normal driving—that's the signal of ABS activation, not a malfunction. For maintenance, remember to clean the wheel speed sensor components to prevent debris from affecting data collection.
