30-07-2012, 03:12 PM
Adaptive Headlight System (AHL)
[attachment=29547]
Introduction
The adaptive headlights (AHL) is available as standard equipment. This system is
installed only in connection with the bi-xenon headlight.
The adaptive headlight performs the exterior lighting functions. It also enables the
bi-xenon low beam and high beam headlight to move within the driving range while
cornering.
The AHL feature requires the following:
• Rain/driving light/solar sensor
• Bi-xenon headlight
The swivel range of the bi-xenon low beam
and high beam headlight is continuously
adapted while cornering. The illuminated
area while cornering therefore improves the
field of view for the driver.
The adaptive illumination while cornering
results in:
• Safer cornering with faster recognition
of obstacles
• Improved perception of surroundings
• Accident avoidance
The electronic module of the adaptive headlight facilitates faster response to the current
road situation. The system is controlled by the electronic module and is therefore less
susceptible than a pure mechanical systems.
In addition, an emergency program can be activated via the electronic module.
Note: The adaptive headlight system is derived from the E90. The footwell
module is therefore the central control unit for the adaptive headlight.
The adaptive headlight has been adapted for use in the E70.
Legal Requirement
The swivel movement of the adaptive headlight is permitted within certain limits to protect
oncoming traffic, i.e. to ensure oncoming traffic is not dazzled by the headlights.
The vehicle moves on a circular path when the driver turns the steering wheel. The circular
path is defined by the movement of the wheels and the angle position of the front
wheels.
In order not to dazzle the oncoming traffic, the salient point of the light/dark limit of the
headlight must not be left of the circular path at a distance corresponding to 100 times
the installation height of the headlight.
This conclusion for the light/dark limit refers to right-hand drive traffic. The conclusion
relating to the light/dark limit applies symmetrically to left-hand drive traffic.
Lights Operating Unit
The light switch must be set to automatic driving lights control in order to switch on the
adaptive headlight. The lights operating unit is connected to the footwell module.
The light switch can be pressed in at a certain pressure in forward direction. This increases
the impact surface area in the vicinity of the light switch in the event of an accident
thus contributing to improved passenger protection.
Direction Indicator/High Beam Switch
The steering column switch cluster contains the direction indicator/high beam switch.
The steering column switch cluster makes available the signal from the direction indicator/
high beam switch hard-wired to the footwell module. A more detailed description of
the steering column switch cluster can
Principles of Operation
Preconditions for the adaptive headlight
To ensure its operability, the adaptive headlight must be adapted to the vehicle specific
data. The vehicle-specific data are located in the footwell module and in the stepper
motor controllers.
The footwell module contains the data:
• Vehicle identification number
• Vehicle type
The stepper motor controller contains the data for:
• Headlight and headlight swivel range
• Permitted acceleration and deceleration ramps
• Characteristic speed maps
• Encoding
• Vehicle identification number
• Vehicle type
Switch-On Conditions
The adaptive headlight can be activated as from terminal status "terminal 15 ON".
Initially, the footwell module switches on the stepper motor controllers. The adaptive
headlight is ready for operation following a reference run of the bi-xenon headlights.
Note: A reference run is performed during every new start.
[attachment=29547]
Introduction
The adaptive headlights (AHL) is available as standard equipment. This system is
installed only in connection with the bi-xenon headlight.
The adaptive headlight performs the exterior lighting functions. It also enables the
bi-xenon low beam and high beam headlight to move within the driving range while
cornering.
The AHL feature requires the following:
• Rain/driving light/solar sensor
• Bi-xenon headlight
The swivel range of the bi-xenon low beam
and high beam headlight is continuously
adapted while cornering. The illuminated
area while cornering therefore improves the
field of view for the driver.
The adaptive illumination while cornering
results in:
• Safer cornering with faster recognition
of obstacles
• Improved perception of surroundings
• Accident avoidance
The electronic module of the adaptive headlight facilitates faster response to the current
road situation. The system is controlled by the electronic module and is therefore less
susceptible than a pure mechanical systems.
In addition, an emergency program can be activated via the electronic module.
Note: The adaptive headlight system is derived from the E90. The footwell
module is therefore the central control unit for the adaptive headlight.
The adaptive headlight has been adapted for use in the E70.
Legal Requirement
The swivel movement of the adaptive headlight is permitted within certain limits to protect
oncoming traffic, i.e. to ensure oncoming traffic is not dazzled by the headlights.
The vehicle moves on a circular path when the driver turns the steering wheel. The circular
path is defined by the movement of the wheels and the angle position of the front
wheels.
In order not to dazzle the oncoming traffic, the salient point of the light/dark limit of the
headlight must not be left of the circular path at a distance corresponding to 100 times
the installation height of the headlight.
This conclusion for the light/dark limit refers to right-hand drive traffic. The conclusion
relating to the light/dark limit applies symmetrically to left-hand drive traffic.
Lights Operating Unit
The light switch must be set to automatic driving lights control in order to switch on the
adaptive headlight. The lights operating unit is connected to the footwell module.
The light switch can be pressed in at a certain pressure in forward direction. This increases
the impact surface area in the vicinity of the light switch in the event of an accident
thus contributing to improved passenger protection.
Direction Indicator/High Beam Switch
The steering column switch cluster contains the direction indicator/high beam switch.
The steering column switch cluster makes available the signal from the direction indicator/
high beam switch hard-wired to the footwell module. A more detailed description of
the steering column switch cluster can
Principles of Operation
Preconditions for the adaptive headlight
To ensure its operability, the adaptive headlight must be adapted to the vehicle specific
data. The vehicle-specific data are located in the footwell module and in the stepper
motor controllers.
The footwell module contains the data:
• Vehicle identification number
• Vehicle type
The stepper motor controller contains the data for:
• Headlight and headlight swivel range
• Permitted acceleration and deceleration ramps
• Characteristic speed maps
• Encoding
• Vehicle identification number
• Vehicle type
Switch-On Conditions
The adaptive headlight can be activated as from terminal status "terminal 15 ON".
Initially, the footwell module switches on the stepper motor controllers. The adaptive
headlight is ready for operation following a reference run of the bi-xenon headlights.
Note: A reference run is performed during every new start.