Electrohydraulic braking
Electrohydraulic brakin (EHB) are designed to anow electronic control of vehicle braking while reduced hydraulic system. The hydraulic system functions as areserve in the event of a failue in the eletronic in control .The EHB control unit receives inputs from sensors connected to the brake pedal. In normal operation, a backup valve closed and the controller activates the brakes of the wheel through an electric motor driven hydraulic pump. When th controller goes into a failsafe mode. the backup valve is opened, which allows the brakes to be controlled through conventional hydraulic circuit .
The benefits of EHB are:
(1) reuses hydraulic system technology while incrementally building on the development of advanced electronic systems, such as electronic stability programs (ESP) , traction control, and brake assist:
(2)uses software updates to simplify the calibration process by adjusting brake response and pedal feel
(3) improves connectivity with other emerging systems, such as adaptive cruise control;
(4) removes the large vacuum servo to allow flexible installation
(5) features an anti-lock braking system (ABS) without feedback from the pedal.
Electrohydraulic braking is based on existing ABS systems with the addition of several enhancements. The inclusion of analog electro hydraulic valves requires closed-loop, current-controlled pulse width modulation ( PWM) outputs from the electronic control unit( ECU) . An EHB system is required to incorporate a failsafe state in the event of a fault occurring. To correctly initiate the failsafe state, the system relies on its electronic components to provide a high level of operational fault coverage.

