Should You Release the Brake Pedal When ABS is Active?
1 Answers
It is correct not to release the brake pedal when ABS is active; instead, you should firmly press the brake pedal. The Anti-lock Braking System, abbreviated as ABS, functions by automatically controlling the braking force during vehicle braking to prevent wheel lock-up, keeping the wheels in a state of rolling and sliding (with a slip ratio of around 20%). This ensures maximum traction between the wheels and the road surface. Below is an introduction to the ABS system: Working Principle: During braking, ABS quickly determines the wheel lock-up state based on speed signals from each wheel speed sensor. It closes the normally open input solenoid valve for the wheel that begins to lock, maintaining the braking force. If the wheel continues to lock, the normally closed output solenoid valve opens, causing the braking pressure on that wheel to rapidly decrease as it connects directly to the brake fluid reservoir. This prevents the wheel from completely locking due to excessive braking force. By keeping the braking state at the optimal point (slip ratio of 20%), the braking effect is maximized, ensuring the safest driving conditions. Limitations: The ABS system also has its limitations and cannot completely defy certain physical laws. In two scenarios, ABS cannot provide the shortest braking distance: one is on smooth, dry roads when braking is performed by an experienced driver, and the other is on loose gravel, dirt, or deep snow-covered roads. Additionally, on dry roads, the latest ABS systems can control the slip ratio within a range of 5% to 20%. However, not all ABS systems operate at the same rate or to the same extent. Although a four-wheel anti-lock braking system can enable the vehicle to brake within the shortest possible distance, if braking is initiated too late and the vehicle cannot come to a complete stop before colliding with an obstacle, it still cannot prevent an accident.
