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Automatic headlamp alignment adjuster
Because of the brightness of the beam emitted by the bulb, the vehicle must have an automatic headlamp alignment adjuster to avoid dazzling oncoming vehicles because of changes in alignment. The device intervenes in certain conditions:
• static type, due to load distribution;
• dynamic type, due to acceleration and deceleration.
The automatic adjuster also ensures greater driving comfort, as the lit area remains stable and the eye does not have to constantly adapt to variations in illumination.
The device comprises:
• a stepper motor for each headlamp;
• two load sensors, connected to the front and rear suspension, right side.
Adjustment
This is achieved via the signal of the load sensors which, connected to the suspension, give an indication of the vehicle's load condition. The control unit is 'activated' whenever the ignition is turned ON and resets the headlamps to the corrrect hight (calculated in relation to the vehicle load), which consists of the full tilting and subsequent positioning of the reflector. The signals of the load sensors are periodically acquired and suitably averaged so as to proceed, if necessary, with an adjustment of the headlamp position (e.g. fuel consumption during driving). This adjustment is not immediate, but is filtered over time to avoid unwanted adjustments (e.g. potholes, rough road surface, etc.). This adjustment is also carried out when the lights are off, so that the beam is correctly positioned the moment when the lights are switched on.
Adjustment actuator
A stepper actuator inside the lights cluster carries out the adjustment. This consists of a stepper motor and a screw-nutscrew reduction gear,
which transforms from rotary into linear the motion of a pushrod hinged via a spherical ball to the reflective surface.
Self-testing
The electronics which manage the system include a self-test function which continuously checks its operation.
The control unit carries out a continuous self-test of the system's operation. In particular, it detects and memorises any faults.
Faults stored in the control unit memory can be analysed by the Examiner or other diagnostic instruments.
Recovery
The self-test management logic also has the 'recovery' function: if errors are detected, the system no longer works correctly, and so
incorrect orientation of the light beam could dangerously dazzle other vehicles.
The light beam is then positioned low so it cannot dazzle under any circumstances, but permits sufficient illumination for safe driving to a
garage on the Service Network.
Resetting
In the case of replacement of a component in the system (headlamp, sensor, etc.), it is necessary to connect up the diagnostic instruments
and carry out a self-learning procedure, to automatically reset the system, which must recognise the headlamp correctly algined position
(position '0') from which it must make the appropriate adjustments.