WABCO TAILGUARD, Описание системы

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System and function System and function
5 .3 Autonomous braking with separate valves
When TailGUARD detects an object, it can act on the compressed-air braking
system of the vehicle, thus braking independently.
Active braking is only permitted if the reservoir pressure on the brake valve (2)
is at least 7.3 bar. This is ensured by a charging valve (3). A pressure limiting
valve (4) is used to define the pressure for active braking and thus for
deceleration.
After approaching an object within a critical distance, the Electronic Extension
Module (1) starts the brake action, controlling two solenoid valves (5) and (6)
via two independent circuits. A braking pressure is only fed if both solenoid
valves switch simultaneously. This rules out a braking process being initiated by
an electrical fault.
A pressure sensor (8) monitors the pressure applied by the solenoid valves.
The service brake is operated by means of a two-way valve (Select-High
valve, 7).
The braking pressure on the brake cylinders is adjusted relative to the
respective load because this pressure is fed by the automatic load-sensing
valve (9).
The Electronic Extension Module switches on the stop light during autonomous
braking. If a fault monitoring system is installed for the stop light, it may need
to be adjusted. If the stop lights are monitored for faults: Fault monitoring must
only be active while the pedal is operated by the driver and LED stop lights
must not be installed.