ABS has four major components….
- This sensor monitors the speed of each wheel and determines the necessary acceleration and deceleration of the wheels. It consists of an exciter (a ring with V-shaped teeth) and a wire coil/magnet assembly, which generates the pulses of electricity as the teeth of the exciter pass in front of it.
Fig:- The speed sensor
- The valves regulate the air pressure to the brakes during the ABS action.
- There is a valve in the brake line of each brake that is controlled by the ABS.
- In the first position, the brake valve is open and it allows the pressure from the master cylinder to be transferred to the brakes.
- In the second position, the brake valve remains closed and pressure from the master cylinder to the brakes is constrained.
- In the third position, the valve releases some of the pressure on the brakes.
- The third step is repeated until the car comes to a halt.
- The resistance that you feel when braking suddenly at high speeds is actually the brake valves controlling the pressure that is being transferred to the brakes from the master cylinder.
3) Electronic Control Unit (ECU)
- The ECU is an electronic control unit that receives, amplifies and filters the sensor signals for calculating the wheel rotational speed and acceleration.
- The ECU receives a signal from the sensors in the circuit and controls the brake pressure, according to the data that is analyzed by the unit.
- 4) Hydraulic Control Unit
- The Hydraulic Control Unit receives signals from the ECU to apply or release the brakes under the anti-lock conditions.
- The Hydraulic Control Unit controls the brakes by increasing the hydraulic pressure or bypassing the pedal force to reduce the braking power.
Working Of Anti-lock Braking System-