Anti-Lock Brake Components

Anti-lock braking systems have revolutionized the way vehicles function in accident situations and hazardous weather conditions. The technology is computer-based with several on-board systems controlling the pressure that is applied to brakes as well as detecting the manner in which the driver applies the brakes to anticipate accident situations and prevent wheel lock-up. Countless lives have been saved by this now-standard piece of vehicle equipment.

Electronic Control Unit

The electronic control unit (ECU) gathers data from the vehicle's sensors to maintain proper function of the car's equipment. In an anti-lock breaking system, the ECU directly operates the hydraulic control unit (HCU), which actively enables valves and sensors that manage anti-lock braking. The electronic control unit will detect the driver's sudden braking and send a signal to the HCU to prevent lock-up.

Hydraulic Control Unit

The hydraulic control unit is closely integrated with the ECU and consists of several solenoid valves that control braking pressure for each of the vehicle's wheels. The HCU essentially does the work that is communicated by the ECU through the vehicle's sensors. This response must run in real time to allow the driver to maintain control of the vehicle during sudden or "panic braking" in response to sudden changes in road conditions or traffic patterns.

Controller Area Network/ Central Control Unit

To enable this real-time functionality of the anti-lock braking system, vehicles employ a controller area network, or CAN system. CAN is a series of programming protocols working in conjunction with the vehicle's central control unit to bind many sensor-based signals into one signal so that the ECU can read them quickly and process the information. The central control unit is a self-policing system consisting of two micro-controllers that monitor each other for proper function.