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Additional functions for driving lights actuation, function - GF82.10-P-3050FL

MODEL 212.0 /2 up to 28.2.13 

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 integrated asymmetric curve illumination 

with CODE (621) Intelligent Light System (left-hand traffic) 

with CODE (622) Intelligent Light System (right-hand traffic) 

Function requirements, general

IMPORTANT Detailed information on the operating state of the transport mode is given in the separate function description for energy management.

IMPORTANT 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 the "drivetrain operational" signal over the chassis CAN (CAN E) to the front SAM control unit with fuse and relay module (N10/1) and to the multifunction camera (A40/11) (with code (608) Adaptive Highbeam Assist). The front SAM control unit sends these signals over the front end CAN (CAN G) to the left xenon light control unit (E1n1) at the left front lamp unit (E1) and to the right xenon light control unit (E2n1) at the right front lamp unit (E2).

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 is achieved by increasing light output and through targeted actuation of additional light sources along with various actuators in the front lamp units. Driving lights actuation is active during actuation of the driving lights actuation additional functions and is described in the "Driving lights actuation, function" document.

The driving lights actuation additional function is comprised of the following subfunctions:

Additional function prerequisites for cornering lights

Function sequence for cornering lights 

The cornering lights improve the illumination of the edge of the road on the inside of the curve. The direct input factors of the cornering lights actuation are the steering 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 actuation characteristic for cornering lights actuation. At slow speed, a lower switch-on point is required to ensure that the cornering lights can be activated early in urban traffic.

Schematic of light distribution for active cornering lights actuation 

Fig 1: Active Cornering Lights Schematic
G00565023Courtesy of MERCEDES-BENZ USA

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. In order to do this, the Electronic Stability Program control unit (N30/4) (model 212 (except 212.074/077/095/098/274/277/298) without code (233) DISTRONIC PLUS), the regenerative braking system control unit (N30/6) (model 212.095/098/298) or the Premium Electronic Stability Program control unit (N30/7) (model 212 (except 212.095/098/298) with code (233) DISTRONIC PLUS, model 212.074/077/274/277) transmit appropriate data via the chassis CAN. The instrument cluster (A1) calculates the vehicle speed to be displayed and sends this over the interior CAN (CAN B) and chassis CAN. The front SAM control unit sends all relevant information over the front end CAN to the xenon light control units, which then evaluate it.

Finally, the left xenon light control unit actuates the left corner illuminating fog lamp (E1e9) or the right xenon light control unit actuates the right corner-illuminating fog lamp (E2e9). Only one cornering light is actuated: the light on the inside of the curve during forward travel and the light on the outside of the curve during reverse travel. 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. 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 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 722.6:

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.

Vehicles with transmission 722.9, 724.2:

Gear range "R" is engaged through the fully integrated transmission control unit (Y3/8n4). The fully integrated transmission control unit then sends the status "gear range R engaged" to the front SAM control unit via the drive train CAN, CDI control unit or ME-SFI [ME] control unit and chassis CAN.

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 angle and the turn signaling function, the actuation sensitivity is increased. The corresponding cornering light is actuated as soon as a curve radius of r ≤ 450m is detected.

When the function request suddenly no longer exists, the corresponding cornering light remains switched on for a holding time of approx. t = 2 s and is switched off within t = 2 s with dimming.

Additional function requirements for dynamic curve illumination 

Function sequence for 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 a = 15°, the headlamp unit on the outside of the curve up to a = 7.5°.

Schematic of light distribution for active dynamic curve illumination function 

Fig 2: Active Dynamic Curve Light Schematic
G00565024Courtesy of MERCEDES-BENZ USA

The dynamic curve light actuation function depends on the following control variables:

The direct input factor is the steering angle, the vehicle speed influences the control response of the function (transformation of steering angle into swivel angle).

At a low vehicle speed, a smaller conversion is required so that the light pattern does not behave in a jumpy manner (e.g. in urban traffic). At medium vehicle speeds an immediate response is given to relatively minor changes in the steering angle and at higher vehicle speeds the responses are dampened again to a greater extent. In order to compensate for the vehicle's natural pendulum motions when driving straight ahead, an area with lower sensitivity and greater damping is provided (approx. ± 6° steering angle).

The selection of the function is made manually through the operation level in the instrument cluster. The instrument cluster sends the corresponding status over the chassis CAN, front SAM control unit and front end CAN to the xenon light control units.

The steering column tube module control unit sends the data from the steering angle sensor, and the Electronic Stability Program control unit or the regenerative braking system control unit sends vehicle movement information to the xenon light control units via the chassis CAN, the front SAM control unit and the front end CAN.

IMPORTANT The yaw behavior of the vehicle is detected by the yaw rate sensor for lateral and longitudinal acceleration (B24/15). This transmits appropriate information to the Electronic Stability Program control unit or the regenerative braking system control unit via the vehicle dynamics CAN (CAN H).

The instrument cluster sends the vehicle speed over the chassis CAN, front SAM control unit and front end CAN to the xenon light control units.

The xenon light control units read in all the relevant data and evaluate it. Finally, 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) over the Local Interconnect Network (LIN) (headlamp-internal).

IMPORTANT The current position of the active curve lights actuator motors and any faults that occur, e.g. such as short circuits or discontinuities, are reported back to the corresponding xenon light control unit.

IMPORTANT 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 glare 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) or code (608) Adaptive Highbeam Assist) 

Function sequence for active light distribution (with code (621) Intelligent Light System (left-hand traffic) or code (622) Intelligent Light System (right-hand traffic) or code (608) Adaptive Highbeam Assist) 

Active light distribution encompasses the following subfunctions:

IMPORTANT The function sequences are described using a left-hand drive vehicle as an example.

Additional function requirements for highway lights 

Function sequence for highway lights 

The freeway lights improve the illumination of the road by increasing the range of the low beams without blinding the preceding traffic. This function is achieved by means of vertically deflecting the light cone and increasing the light output. The freeway lights are activated at speeds typical for the freeway or expressway.

IMPORTANT The freeway lights function is deactivated when it is raining. Rain detection takes place by evaluating the windshield wiper signal (windshield wiper not in park position).

If the windshield wiper is in the park position less than t = 600 ms, this is evaluated as continuous wipe. Rain is detected if the continuous wipe function is active for t > 2 min.

Schematic of light distribution for active freeway lights function 

Fig 3: Active Freeway Lights Function Light Schematic
G00565025Courtesy of MERCEDES-BENZ USA

The highway lights function depends on the following control factors:

The selection of the function is made manually through the operation level in the instrument cluster. The instrument cluster sends the corresponding status over the chassis CAN to the front SAM control unit and over the chassis CAN, front SAM control unit and front end CAN to the xenon light control units.

The steering column tube module control unit sends the data from the steering angle sensor, and the Electronic Stability Program control unit or the regenerative braking system control unit sends vehicle movement information to the xenon light control units via the chassis CAN, the front SAM control unit and the front end CAN. The instrument cluster sends the vehicle speed over the chassis CAN, front SAM control unit and front end CAN to the xenon light control units. The xenon light control units read in all the relevant data and evaluate it. Starting at a vehicle speed of v = 90 km/h and a curve radius of r > 800 m for a driving distance of more than s = 2.5 km, 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.

The left xenon light control unit as from a speed of v = 110 km/h and a curve radius of r > 800 m for more than s = 1 km driving distance, actuates the left headlamp range adjustment actuator motor (E1m1). The headlamp unit of the left front lamp unit is raised. The range of the low beams is thus increased. The maximum lift is reached at v = 130 km/h. If the vehicle speed drops down to below v = 80 km/h, the "highway lights" function is disabled.

Additional function requirements for extended fog light function 

Extended fog light function sequence 

The extended fog light function improves the illumination of the edges of the road and reduces the internal dazzling. It is activated at speeds typical of urban traffic and rural roads. The xenon bulb light cone in the front lamp unit facing the inside of the road is raised and swiveled outwards at vehicle speeds below v = 70 km/h.

Schematic of light distribution for active extended fog light function 

Fig 4: Active Extended Fog Light Function Light Schematic
G00565026Courtesy of MERCEDES-BENZ USA

The selection of the function is made manually through the operation level in the instrument cluster. The instrument cluster sends the corresponding status and the vehicle speed over the chassis CAN, front SAM control unit and front end CAN to the left xenon light control unit.

The left xenon light control unit reads in all the relevant information, evaluates it and 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 a = 8° and the part of the light-dark boundary that slopes to the right is covered. Internal dazzling is reduced and illumination of the road surface at the side is improved.

IMPORTANT If the "extended fog light function" is active, the "dynamic curve illumination" function is deactivated.

If the high beams function is requested while the "Extended fog light function" is active, the position of the headlamp unit is retained.

IMPORTANT The left daytime running lights headlamp (E1/3) and the right daytime running lights headlamp (E2/3) (without code (498) Japan version up to 31.5.10 and without code (835) South Korea version) are switched off because of the possible internal dazzle.

The extended fog light function is deactivated under the following conditions:

IMPORTANT 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) 

Function sequence for adaptive high beams (with code (608) Adaptive Highbeam Assist) 

The adaptive high beams function is an assistance function. The headlamp range of the driving lights is adapted to the distance of the nearest preceding or oncoming road user by means of actuation of various actuators in the front lamp units. If no road users are detected, the adaptive high beams function automatically activates the high beams.

Fig 5: Adaptive Highbeam Assist Light Range
G00565027Courtesy of MERCEDES-BENZ USA

The selection of the function is made manually through the operation level in the instrument cluster. The instrument cluster transmits the corresponding status via interior CAN to the front SAM control unit.

The steering column tube module control unit sends the position of the combination switch over the chassis CAN to the front SAM control unit. The front SAM control unit reads in the status of the exterior lights switch.

After evaluating all function requirements, the front SAM control unit sends the enabling of the adaptive high beams function via chassis CAN to the multifunction camera. The activated adaptive high beams function is displayed by a symbol in the multifunction display (A1p13) in the instrument cluster. The front SAM control unit sends the "Adaptive high beams active" status via interior CAN to the instrument cluster for this. The multifunction camera also evaluates the following information, among other things, to implement the adaptive high beams function:

The steering angle sensor data is sent by the steering column tube module control unit, and information about the wheel speed and wheel rotation direction as an indicator of the vehicle speed and vehicle yaw characteristics is sent by the Electronic Stability Program control unit or the regenerative braking system control unit to the multifunction camera via the chassis CAN.

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 front lamp units ensures the best possible illumination of the roadway 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 picture recognition module integrated into the multifunction camera judges the distance to the 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.

A distinction is made between the following functions states:

Optical headlamp range adjustment:

Depending on the distance of the vehicle to other road users and the geometry of the road (differences in height, angle), the multifunction camera sends the "Optical headlamp range adjustment" request via chassis CAN, front SAM control unit and front end CAN to the xenon light control units. The left xenon light control unit then actuates the left headlamp range adjustment actuator motor and the right xenon light control unit actuates the right headlamp range adjustment actuator motor (E2m1) via LIN (headlamp-internal). 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 light cone of the xenon light varies between s = 65 m (standard lighting) and s = 300 m. If the vehicle speed drops below v = 40 km/h, the optical headlamp range adjustment is deactivated.

Automatic high beams:

The xenon bulb light cones are not fully released until vehicle speed is greater than v = 55 km/h and no other road users are detected. To this end, the xenon light control units also actuate the light distribution actuator motors over LIN (headlamp internal). The rollers which partially cover up the xenon bulb's light cone, are turned away thereby uncovering the entire light beam to illuminate the traffic lane.

The multifunction camera sends the request for this via chassis CAN, front SAM control unit and front end CAN to the xenon light control units. If the vehicle speed sinks below v = 45 km/h, the automatic high beams are deactivated. The activation or deactivation speed of the automatic high beams is controlled adaptively by the multifunction camera.

IMPORTANT As soon as the automatic high beams are activated, the high beams indicator lamp (A1e3) in the instrument cluster lights up. On roads with street lamps positioned regularly, the automatic high beams are deactivated. Limits of the adaptive high beams: In tight curves, the multifunction camera may not recognize oncoming vehicles or only do so very late due to the recording angle (∠ = 35°). The automatic high beams are deactivated depending on the steering angle. 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. The automatic high beams are not switched off.

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 crests, oncoming vehicles are not recognized until late and the automatic high beams are therefore 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, lot illumination), the automatic high beams are deactivated. Some reflectors cannot be clearly differentiated by road users (e.g. motorcyclists). The automatic high beams are deactivated because of the existing danger of dazzling other road users.

  Electrical function schematic, additional functions, driving lights actuation   PE82.10-P-2063-97DAA
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