Brief Introduction to the Working Principle of ABS System
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ABS system, also known as the Anti-lock Braking System, works on the principle that: During braking, the ABS system, based on the speed signals from each wheel speed sensor, closes the normally open input solenoid valve for the wheel that begins to lock up, keeping the braking force constant. If the wheel continues to lock, the normally closed output solenoid valve is opened. This keeps the braking state always at the optimal point, achieving the best braking effect and ensuring the highest driving safety. ABS, short for Anti-lock Braking System, functions to automatically control the magnitude of the braking force during vehicle braking, preventing the wheels from locking up and maintaining a state of rolling while slipping (with a slip ratio of about 20%), ensuring maximum adhesion between the wheels and the road surface. The ABS system mainly consists of four components: wheel speed sensors, electronic control unit (ECU), hydraulic unit, and ABS warning light. The wheel speed sensors detect the motion state of the wheels, generating sinusoidal electronic pulse AC 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 parameters such as wheel speed, vehicle speed, and slip ratio, and determines the wheel state based on the slip ratio, issuing 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 holding, pressure increase, and pressure decrease. The ABS warning light is used to alert the driver to any system faults. If the ABS warning light is on, it is advisable not to continue driving, as it indicates a fault in the vehicle's anti-lock braking system. During emergency braking, if the wheels lock up, the vehicle may lose control and skid, making it difficult for the driver to decelerate or adjust the vehicle's trajectory, posing significant safety risks.
