GF82.10-P-3050CA Additional Functions For Driving Lights Actuation, Function
GF82.10-P-3050CA Additional Functions For Driving Lights Actuation, Function
- with CODE (608) Adaptive Highbeam Assist
- with CODE (615) Bi-xenon headlamp unit with integrated curve illumination
- with CODE (616) Bi-xenon headlamp unit with intergrated asymmetrical curve illumination
- with CODE (621) Intelligent Light System (left-hand traffic)
- with CODE (622) Intelligent Light System (right-hand traffic)
Function requirements for additional functions of driving lights actuation, general
^ No overvoltage or undervoltage
(operating voltage range U ≥7 ≤17.5 V)
^ Low beam ON
^ Engine is running (n > 300 rpm) or circuit 61 On
The status of circuit 61 and the engine speed are sent by the CDI control unit (N3/9) (with diesel engine) or the ME-SFI [ME] control unit (N3/10) (with gasoline engine) via chassis CAN (CAN E).
Additional functions, driving lights actuation, general
The additional functions of driving lights actuation permit optimum illumination of the roadway for different road and weather conditions.
This takes place by increasing the light output, selectively actuating additional light sources and various actuators in the left front lamp unit (E1) or in the right front lamp unit (E2). Driving lights actuation is active during actuation of the driving light additional functions, and is described in a separate document.
The additional functions of driving lights actuation are comprised of the following subfunctions:
^ Cornering lights function sequence
^ Function sequence, dynamic curve illumination
^ Function sequence for active light distribution (with code (621) Intelligent Light System (left-hand traffic) or code (622) Intelligent Light System (right-hand traffic) and code (608) Adaptive Highbeam Assist)
Additional function requirements, cornering illumination
^ Turn signaling active and speed v < 40 km/h (without code (494) USA version) or v < 60 km/h (with code (494) USA version) or steering angle recognized and speed v < 70 km/h
^ Radius of curve r ≤500 m
Cornering lights function sequence
The cornering lights function's direct input factors are the steering wheel angle, recorded by the steering angle sensor (N49), and the turn signaling function, defined by the switch position of the combination switch (S4), since they describe the driver's required direction.
The vehicle speed influences the system behavior of the turning light actuation. At a slower vehicle speed a lower switch-on point is required to ensure that the cornering light actuation can be activated early in urban traffic.
The steering column tube module control unit (N80) reads in the data of the steering angle sensor and the switch position of the combination switch and transmits them via chassis CAN.
The vehicle speed is calculated on the basis of the wheel speeds.
For this purpose, the Electronic Stability Program control unit (N30/4) (without code (233) DISTRONIC PLUS) or the Electronic Stability Program Premium control unit (N30/7) (with code (233) DISTRONIC PLUS) transmits the corresponding data via chassis CAN to the instrument cluster (A1). The instrument cluster calculates the vehicle speed to be displayed and transmits this via interior CAN (CAN B).
The front SAM control unit with fuse and relay module (N10/1) forwards all relevant information via front end CAN (CAN G) to the left xenon light control unit (E1n1) and to the right xenon light control unit (E2n1). The left xenon light control unit then actuates the left corner-illuminating fog lamp (E1e9) or the right xenon light control unit the right corner-illuminating fog lamp (E2e9).
Only one cornering light is actuated: the inside corner light during forward travel and the outside corner light during reverse travel. The corresponding cornering light is switched on and off with dimming.
The request by the turn signaling function has a higher priority below a speed of v = 40 km/h compared with the request by the detection of the steering wheel angle in order to ensure the illumination of the edge of the road on the inside of the curve when the steering wheel is turned and turning in the opposite direction (situation at traffic circles). When the reverse gear is engaged, only the data of the steering angle sensor is evaluated.
The "reverse gear engaged" status is defined as follows. Vehicles with transmission 711, 716:
Engagement of the reverse gear is defined through the status of the backup lamp switch (S16/2), which is read in directly by the front SAM control unit.
Vehicles with transmission 722:
The request to engage gear range "R" is defined by the corresponding selector lever position .
The electronic selector lever module control unit (N15/5) sends the selector lever position via drive train CAN (CAN C), CDI control unit, or ME-SFI [ME] control unit and chassis CAN to the front SAM control unit.
Located in the front SAM control unit are two microprocessors, one for control of basic functions e.g. the exterior lights, and the second for control of the central gateway functions. Both processors communicate with each other internally via interior CAN.
The microprocessor for control of the central gateway functions uses all incoming information to generate the "Reverse gear engaged" signal that is independent from the type of transmission and transmits it via front end CAN to the xenon light control units.
If the cornering lights function is requested simultaneously by the detected steering wheel angle and the turn signaling function, the system sensitivity is reduced. The corresponding cornering light is actuated as soon as a curve radius of r ≤500m is detected.
When the function request suddenly no longer exists, the corresponding cornering illumination remains switched on for a holding time of approx. t = 2 s and is switched off within t = 2 s with dimming.
If there is a rapid change in the steering wheel angle or in the turn signaling request, both corner-illuminating fog lamps may illuminate briefly.
Additional function requirements, dynamic curve illumination
^ Function "Intell. Light System:" activated in the "Lights" menu in the instrument cluster
^ Vehicle moving forward
^ "Extended fog light" function disabled
Function sequence, dynamic curve illumination
Dynamic curve illumination improves the road illumination when cornering. For this the low beam cone is swiveled horizontally towards the center point of the curve. A conventional bi-xenon headlamp serves as a basis, the headlamp unit of which is supported in a retaining frame so that it can swivel. When steering into a curve the headlamp unit on the inside of the curve is swiveled up to alpha = 15°, the headlamp unit on the outside of the curve up to alpha = 7.5°.
The dynamic curve light actuation function depends on the following controlled variables:
- Steering wheel angle
- Vehicle speed
- Yaw characteristics of the vehicle
The steering wheel angle is the direct input parameter. The vehicle speed influences the system's control response (ratio of steering angle to swivel angle).
At a low vehicle speed a lower transformation is required so that the light pattern does not behave in a jumpy manner, in urban traffic for example.
At medium speeds direct reactions take place to relatively small steering wheel angle changes and at higher speeds the system reactions are increasingly damped again. To compensate for the natural oscillating movement of the vehicle when driving straight ahead, an area with lower sensitivity and enhanced damping has been provided (approx. ±6° steering wheel angle).
The steering wheel angle recorded by the steering angle sensor is transmitted by the steering column tube module control unit, the vehicle movement information is transmitted by the Electronic Stability Program control unit, and the vehicle speed is transmitted by the instrument cluster via chassis CAN, front SAM control unit, and front end CAN to the xenon light control units.
The yaw behavior of the vehicle is detected by the yaw rate sensor for lateral and longitudinal acceleration (B24/15). This transmits appropriate data to the electronic stability program control unit via the vehicle dynamics CAN (CAN H).
The left xenon light control unit actuates the left active curve lights actuator motor (E1m2), and the right xenon light control unit actuates the right active curve lights actuator motor (E2m2) via the Local Interconnect Network (LIN) (headlamp-internal).
The current position of the active curve illumination actuator motors and faults occurring, such as short circuits or discontinuities, are reported back to the corresponding xenon light control unit.
If the curve illumination actuation is defective, the headlamp units are, if possible, swiveled into the central position.
If an active curve lights actuator motor malfunctions, the left light distribution actuator motor (E1m3) or the right light distribution actuator motor (E2m3) is actuated to cover up the rising part of the light-dark boundary and thereby reduce the dazzling effect for oncoming traffic.
Additional function requirements for active light distribution (with code (621) Intelligent Light System (left-hand traffic) or code (622) Intelligent Light System (right-hand traffic) and code (608) Adaptive Highbeam Assist)
^ Vehicle moving forward
Function sequence for active light distribution
(with code (621) Intelligent Light System (left-hand traffic) or code (622) Intelligent Light System (right-hand traffic) and code (608) Adaptive Highbeam Assist)
The active light distribution is comprised of the following subfunctions:
^ Motorway lights function sequence
^ Extended fog light function sequence
^ Function sequence for adaptive high beams
(with code (608) Adaptive Highbeam Assist)
The function sequences are described using a left-hand drive vehicle as an example.
Additional function requirements, motorway lights
^ Function "Intell. Light System:" activated in the "Lights" menu in the instrument cluster
^ Extended fog light function inactive
^ Radius of curve r ≥800 m
Motorway lights function sequence
The motorway lights enable optimum illumination of the roadway at high vehicle speeds.
This is achieved by increasing the light output and vertically deflecting the low beam cone.
The motorway lights function is deactivated when it is raining. Rain is detected by evaluating the windshield wiper signal (windshield wiper not in park position). If the windshield wiper is in the park position for less than t = 600 ms, this is evaluated as continuous wiping. Rain is detected if the continuous wipe function is active for t > 2 min.
The motorway lights function depends on the following set variables:
- Steering wheel angle
- Vehicle speed
- Yaw characteristics of the vehicle
The release of the motorway lights function takes place manually via the operation level in the instrument cluster. The instrument cluster transmits the corresponding status via chassis CAN to the front SAM control unit.
The steering wheel angle recorded by the steering angle sensor is transmitted by the steering column tube module control unit, the vehicle movement information is transmitted by the Electronic Stability Program control unit, and the vehicle speed is transmitted by the instrument cluster via chassis CAN, front SAM control unit, and front end CAN to the xenon light control units.
The front SAM control unit receives all relevant information and transmits it to the xenon light control units via the front end CAN.
Starting at a vehicle speed of v = 70 km/h, the light output of the left xenon bulb with integrated ignition module (E1e10) and the right xenon bulb with integrated ignition module (E2e10) is increased linearly up to P = 38 W by the corresponding xenon light control unit
Under the following conditions the light distribution actuator motors are also actuated to release a part of the covered up low beam light cone for the xenon bulbs, whereby the low beam range is then increased:
- v > 110 km/h for a distance of more than s = 1 km or
- v > 130 km/h
If the vehicle speed drops down to below v = 80 km/h, the "motorway lights" function is disabled.
Additional function requirements, extended fog light function
^ Function "Intell. Light System:" activated in the "Lights" menu in the instrument cluster
^ Rear fog lights actuation active
Function sequence for extended fog light function (using left-hand drive vehicle as an example)
The extended front fog light function is enabled manually via the operation level in the instrument cluster. The instrument cluster transmits the corresponding status via chassis CAN to the front SAM control unit.
At a vehicle speed of less than v = 70 km/h the left xenon light control unit actuates the left light distribution actuator motor and the left active curve lights actuator motor. The headlamp unit of the left front lamp unit is swiveled outwards by Alpha = 8° and the part of the light-dark boundary that slopes to the right is covered. This in turn serves to reduce internal dazzling and the side illumination of the travel lane is improved.
If the extended fog light function is active, the dynamic curve illumination function is deactivated.
If the high beams function is requested with active extended fog lights, the position of the headlamp unit is retained.
The left daytime running lights headlamp (E1/3) and the right daytime running lights headlamp (E2/3) are switched off due to possible internal dazzling.
The extended fog light function is deactivated under the following conditions:
- Failure of a lamp unit (low beam)
- Malfunctions in left light distribution actuator motor or left active curve lights actuator motor
When testing and adjusting the front lamp unit, ensure that the extended fog light function is not active.
Additional function requirements for adaptive high beams (with code (608) Adaptive Highbeam Assist)
^ "Adaptive Highbeam Assist" function: activated in the "Lights" menu in the instrument cluster
^ High beams function request via combination switch
Function sequence, adaptive high beams (with code (608) Adaptive Highbeam Assist)
The adaptive high beams function is an assistance function in which the range of the xenon bulbs is adapted to the distance of the nearest road user ahead or driving in the opposite direction. The functional scope of the adaptive high beams is also known as "Optical headlamp range adjustment".
If no road users are detected, the adaptive high beams function automatically activates the high beams.
A distinction is made between the following functions states:
- Optical headlamp range adjustment
- Automatic high beams
The adaptive high beams function is enabled manually via the operation level in the instrument cluster.
The instrument cluster transmits the "Activate Adaptive Highbeam Assist" request via the interior CAN to the front SAM control unit.
The front SAM control unit checks all relevant parameters cyclically and then grants the approval. The xenon light control units receive them via the front end CAN. The multifunction camera (A40/11) receives the function approval via the chassis CAN. A corresponding symbol appears in the multifunction display (A1p13), which indicates function readiness.
During active output of the high beams function, the xenon light control units transmit the "High beams active" status via the front end CAN to the front SAM control unit, which forwards it via the interior CAN to the instrument cluster. The instrument cluster then actuates the high beam indicator lamp (A1e3).
The following information on the vehicle's movement is used for implementing the adaptive high beams function:
- Steering wheel angle and steering wheel velocity
- Vehicle speed
- Yaw characteristics of the vehicle
The steering wheel angle recorded by the steering angle sensor and the switch position of the combination switch are transmitted by the steering column tube module control unit, the vehicle movement information is transmitted by the Electronic Stability Program control unit, and the vehicle speed is transmitted by the instrument cluster via chassis CAN to the multifunction camera.
The traffic and environment situation in front of the vehicle is detected by the multifunction camera and accordingly evaluated. Activation of the actuators installed in the lamp units ensures that the roadway is perfectly illuminated without generating any dazzling effect for 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 image recognition module integrated into the multifunction camera estimates the distances to other road users, evaluates the external brightness of the vehicle's environment, and recognizes extreme weather conditions (dense fog, heavy snowfall), as well as driving through a tunnel.
Within a vehicle speed range of v = 40 to 60 km/h, ideal illumination of the roadway is achieved by partially releasing the light cones of the xenon bulbs by actuating the light distribution actuator motors.
The light cones are not completely released until a vehicle speed of v = 60 km/h is exceeded.
When the vehicle speed falls below less than v = 50 km/h is detected, the light cones on the xenon bulbs are partially covered up again.
The corresponding request is sent by the multifunction camera over the chassis CAN to the front SAM control unit, which then makes it available to the xenon light control units on the front end CAN. The xenon light control units actuate the light distribution actuator motors, whereby the covers that partially cover up the xenon bulb light cones, are folded away.
