Function Of Adaptive High Beam Assist - GF82.10-P-3091RDM
Model 172.4 as of model year 2017
with code 608 (Adaptive High Beam Assist)
with code 628 (Adaptive High Beam Assist Plus)
Function requirements for Adaptive High Beam Assist in general
- No overvoltage or undervoltage (operating voltage range U ≥ 7 ≤ 17.5 V)
- Transport mode not activated
- "Engine running" or "drive train operational" signal on
- Function in instrument cluster (A1) activated
- Low beams On (exterior lights switch (S1) in "A" position and light sensor (B38/1) or rain/light sensor (B38/2) recognizes darkness)
- Combination switch (S4) in "High beams" position
Detailed information on the transport mode operating condition is available in a separate document.
The function requirements are read in as follows:
The CDI control unit (N3/9) (with diesel engine) or the ME-SFI [ME] control unit (N3/10) (with gasoline engine) sends the "Engine running" or "Drive train operational" signal via chassis CAN 1 (CAN E1) to the front SAM control unit with fuse and relay module (N10/1).
The Adaptive High Beam Assist function is manually enabled using the control level in the instrument cluster. The instrument cluster sends the corresponding status via interior CAN (CAN B) to the front SAM control unit.
The "Low beams ON" status is generated by the front SAM control unit itself. To do so, the front SAM control unit reads in the status of the exterior lights switch directly and the data from the light sensor or the rain/light sensor via the wiper/inside rearview mirror LIN (LIN 2). The low beams indicator lamp (A1e67) in the instrument cluster is actuated in every functional state. To this end, the front SAM control unit sends the "Switch on low beams indicator lamp" request via interior CAN to the instrument cluster.
The steering column tube module control unit (N80) reads in the switch position of the combination switch directly and sends this over chassis CAN 1 to the front SAM control unit.
The front SAM control unit is the master control unit for the exterior lights. The front SAM control unit reads in the function requirements and issues an enable signal to the multifunction camera (A40/11). The multifunction camera is the master control unit for the Adaptive High Beam Assist.
Adaptive High Beam Assist, general
The traffic and environment situation in front of the vehicle is detected by the multifunction camera and accordingly evaluated. Actuating the actuators integrated in the left front lamp unit (E1) and the right front lamp unit (E2) serves to ensure that the road is ideally illuminated without dazzling any of the other road users. The multifunction camera uses the brightness, shape, structure, color, where applicable, and motion of detected objects to differentiate between preceding or oncoming road users, street lighting, signs or other parts of the infrastructure. The picture recognition module integrated into the multifunction camera judges the distance, e.g. to other road users, evaluates the outside brightness level of the vehicle environment and recognizes extreme weather conditions (e.g. thick fog, heavy snowfall) or tunnels.
The multifunction camera evaluates the following information to realize the function:
- Steering wheel angle
- Vehicle speed
- Yaw behavior
The steering column tube module directly reads in the data of the steering wheel angle sensor (N49) and sends it via chassis CAN 1, front SAM control unit and chassis CAN 2 (CAN E2) to the multifunction camera.
The vehicle speed is calculated on the basis of the wheel speeds. To do so, The Electronic Stability Program control unit (N30/4) sends corresponding data via chassis CAN 1 and front SAM control unit, chassis CAN 2 to the multifunction camera.
The yaw behavior of the vehicle is detected by the turn rate sensor for lateral and longitudinal acceleration (B24/15). This sends the corresponding information via vehicle dynamics CAN (CAN H), Electronic Stability Program control unit, chassis CAN 1, front SAM control unit and chassis CAN 2 to the multifunction camera.
A differentiation is made between the following Adaptive High Beam Assist functional states:
- Optical headlamp range adjustment (as of approx. v = 25 km/h)
The headlamp range of the low beam is automatically adapted to the distance to other road users.
- Automatic high beams (as of approx. v = 30 km/h)
If no other road users are detected, the high beams are activated.
- Partial high beam (as of approx. v = 45 km/h) (with code 628 (Adaptive High Beam Assist Plus))
The partial high beam places road users in the low beam section of the light cone thereby omitting them from the high beam.
Schematic diagram
Optical headlamp range adjustment (as of approx. v = 25 km/h)
The multifunction camera sends the "Optical headlamp range adjustment" request to the left headlamp control unit (E1n9) and the right headlamp control unit (E2n9), depending on the distance of the vehicle to other road users and the geometry of the road (height differences, angle). The multifunction camera sends the request via chassis CAN 2 to the headlamp control units.
The left headlamp control unit directly actuates the left headlamp range adjustment actuator motor (E1m1) and via left headlamp LIN (LIN G1) and left front actuation module, LED exterior lighting (E1n7) the "Low beams" in the left low beam (short range) (E1e15) and in the left low beam (long range) and high beam (E1e16).
The right headlamp control unit directly actuates the right headlamp range adjustment actuator motor (E2m1) and via right headlamp LIN (LIN G2) and right front actuation module, LED exterior lighting (E2n7) the "Low beams" in the right low beam (short range) (E2e15) and in the right low beam (long range) and high beam (E2e16).
The headlamp units of the front lamp units are raised accordingly. The road surface is better illuminated without causing a dazzling effect for other road users.
The headlamp light cone varies between s = 65 m (standard lighting) and s = 300 m.
Automatic high beams (as of approx. v = 30 km/h)
If no other road users are detected by the multifunction camera, the automatic high beams are activated. The multifunction camera sends the "High beams ON" request over the chassis CAN 2 to the headlamp control units. The activated automatic high beams function is visually indicated to the driver. To this end, the front SAM control unit sends the "High beams ON" request via interior CAN to the instrument cluster. The instrument cluster actuates the high beams indicator lamp (A1e3).
The left headlamp control unit directly actuates the left light distribution actuator motor (E1m3) and via left headlamp LIN and left front actuation module, LED exterior lighting the "High beams" in the left low beam (long range) and high beam.
The right headlamp control unit directly actuates the right light distribution actuator motor (E2m3) and via right headlamp LIN and right front actuation module, LED exterior lighting the "High beams" in the right low beam (long range) and high beam.
On roads with street lamps positioned regularly, the automatic high beams are deactivated.
Partial high beam (as of approx. v = 45 km/h) (with code 628 (Adaptive High Beam Assist Plus))
When the multifunction camera recognizes other road users, the partial high beam is activated. The activated partial high beams function is visually indicated to the driver. To this end, the front SAM control unit sends the "High beams ON" request via interior CAN to the instrument cluster. The instrument cluster actuates the high beams indicator lamp.
Depending on the distance between the vehicle and other road users and the road geometry (height differences, angle), the multifunction camera sends the "Light output setting" and the "Rotation angle setting" request via chassis CAN 2 to the headlamp control units. The left headlamp control unit actuates the left light distribution adjustment actuator motor directly.
The left headlamp control unit increases the light output of the "High beams" in the left low beam (long range) and high beam via left headlamp LIN and left front actuation module, LED exterior lighting.
The right headlamp control unit actuates the right light distribution adjustment actuator motor directly.
The right headlamp control unit increases the light output of the "High beams" in the right low beam (long range) and high beam via right headlamp LIN and right front actuation module, LED exterior lighting.
Adaptive High Beam Assist limits
In tight curves, the multifunction camera may not recognize oncoming vehicles or only do so very late due to the recording angle (∠ = 35°).
On streets with structural separation (e.g. guardrails on freeways) the headlamps of oncoming vehicles are often concealed. These vehicles are not recognized by the multifunction camera.
Due to the geometry of the structural separation and the location of the headlamps on cars, the drivers of the oncoming cars are not dazzled. Truck drivers, however, are dazzled due to the high seat position. The clearance lamps on trucks are not sufficient for recognition.
When driving over hills, oncoming vehicles are not recognized until late whereupon the high beams are also switched off later. In this situation, however, the driver of the oncoming vehicle is also dazzled by the low beams.
Lights that are visible for a long time and that slowly become brighter (e.g. with partial concealment of the headlamps by trees) make it more difficult to recognize oncoming vehicles.
With bright lights that appear suddenly (e.g. street lamps, traffic lights, illumination of lots), the high beams are deactivated.
Some reflectors cannot be clearly differentiated from road users (e.g. motorcyclists). The high beams are deactivated because of the danger of dazzling other road users.
| Function schematic for Adaptive High Beam Assist | PE82.10-P-2066-97TAB | ||
| Overview of exterior lights system components | GF82.10-P-9998RDM |