Anti-lock brake system (ABS) sensors, also known as wheel speed sensors, play a vital role in modern vehicle safety by monitoring the speed of each wheel. Its primary function is to provide data to the ABS control module, allowing the system to prevent wheel lockup during braking and maintain better control of the vehicle. ABS sensor function and working principle:
Influence:
Monitor wheel speed: By sensing wheel speed, the ABS sensor can quickly determine the status of the wheel, especially when the wheel is about to lock, and transmit the signal to the ABS control module.
Prevent wheel locking: The ABS system controls the amount of braking force to prevent wheel locking and keep the wheels rolling and sliding, thereby ensuring maximum adhesion between the wheels and the ground and improving driving safety.
Tire pressure monitoring: The ABS sensor plays a key role in the indirect tire pressure monitoring system. By comparing the rotational speeds of the four tires, the ABS sensor detects changes in tire pressure.
Loose tire screws monitoring: On some models, the ABS sensor also has the function of monitoring whether the tire screws are loose, that is, the wheel looseness alarm function.
Working principles:
Sensor structure: The ABS sensor mainly consists of a wheel speed sensor, a brake pressure regulator and an electronic controller (ECU). The wheel speed sensor is usually installed on each wheel, and the ring gear that rotates synchronously with the wheel outputs a set of quasi-sinusoidal alternating current signals, the frequency and amplitude of which are related to the wheel speed.
Working process: During emergency braking, the ABS system controls the brake pressure regulator to adjust the braking force of each wheel based on the speed signal of each wheel speed sensor. If the wheel continues to lock, the system will open the normally closed output solenoid valve to reduce the braking force; if the wheel speed increases, the system will close the normally open input solenoid valve to keep the braking force unchanged.
Signal processing: When the signals output by the ABS sensor are transmitted to the ABS electronic control unit (ECU), the ECU will monitor the wheel speed in real time based on these signals and issue corresponding instructions to control the braking force to achieve the best braking effect.
