GF54.30-P-0005FL Night Vision Assist, Function

GF54.30-P-0005FL Night Vision Assist, Function
- with CODE (610) Night vision assist

Function requirements, general
^ Circuit 15 On
^ The rain/light sensor (B38/2) detects "Twilight" or "Night" when exterior lights switch is (S1) in "Auto" or "Manual driving lights"position
^ Speed v ≤260 km/h (forward travel)

The request to "switch on low beams" can only be issued with circuit status circuit 15 ON. The electronic ignition lock control unit (N73) transmits circuit 15 status to the front SAM control unit with fuse and relay module (N10/1) via the interior CAN (CAN B).

Night View Assist, general
The Night View Assist system records the course of the road in front of the vehicle during darkness and shows this in the Audio/ COMAND display (A40/8).
This means that persons and obstacles are recognized in good time before these would become visible in the conventional low beam. The road in front of the vehicle is also illuminated with infrared light at night and at a vehicle speed of v > 15 km/h. The night view assist camera (B84/2) is designed for infrared light and records the area in front of the vehicle. The picture recorded by the system corresponds to the view through the windshield with the high beams switched on. Infrared light is invisible to the human eye.
Oncoming traffic is thus not dazzled.

The Night View Assist system detects persons who move on dark roads outside built-up areas. This person detection is called "Intelligent Nightview" (night view with person detection).
The persons detected are shown highlighted with corners in the Audio-/COMAND Display.
Person detection is possible up to a distance of s = 90 m in front of the vehicle.

Function sequence for Night View Assist
The master control unit of the Night View Assist system is the Night View Assist control unit (N101). This evaluates the following information provided by the chassis CAN (CAN E):
- Status of Night View Assist button (S1s9)
- Rain/light sensor data
- Low beams activation status
- Wheel speeds, vehicle dynamics
- Vehicle speed
- Status of reverse gear
- Status of low beam actuation

The System Night View Assist system is activated manually by pressing the Night View Assist button. The front SAM control unit reads in the status of the Night View Assist button via the instrument panel LIN (LIN 1) and transmits this to the Night View Assist control unit via the chassis CAN.

According to ambient brightness, the Night View Assist system differentiates between the following operating modes:
- Twilight mode
- Night mode (low beams activated by "Auto on/off headlamps")

In twilight mode the pictures recorded by the Night View Assist camera are represented in the Audio/COMAND display.

In night mode the left infrared light (E1e11) is also switched on in the left front lamp unit (E1) and the right infrared light is switched on in the right front E2e11 lamp unitE2

For this the Night View Assist control unit transmits the request to switch on the infrared lights via the chassis CAN to the front SAM control unit which then actuates the infrared lamps accordingly.

The infrared lights are switched off once a vehicle speed of v = 5 km/h is reached. The actuation of the infrared lamps via diagnosis-tester for diagnosis purposes is currently not possible.

The changeover between the operating modes takes place after the evaluation of the rain/light sensor data. These are read in by the front SAM control unit via the wiper/inside rearview mirror LIN (LIN 2) and supplied to the Night View Assist control unit via the chassis CAN.

The vehicle speed is calculated on the basis of the wheel speeds.

The wheel speeds are recorded by the following components:
- Left front axle rpm sensor (L6/1)
- Right front axle rpm sensor (L6/2)
- Left rear axle rpm sensor (L6/3)
- Right rear axle rpm sensor (L6/4)

The Electronic Stability Program control unit (N30/4) (without code (233) DISTRONIC PLUS) or Electronic Stability Program Premium control unit (N30/7) (with code (233) DISTRONIC PLUS) reads in the signals of the rpm sensors and transmits these via the chassis CAN to the IC (A1) and to the Night View Assist control unit. The IC calculates the vehicle speed to be displayed and transmits this via the chassis CAN to the Night View Assist control unit. Information on the natural dynamics of the vehicle is transmitted by the yaw rate sensor for lateral and longitudinal acceleration (B24/15) via the vehicle dynamics CAN (CAN H) to the Electronic Stability Program control unit which passes this on via the chassis CAN to the Night View Assist control unit.

The steering angle is also taken into account. The steering angle sensor (N49) records information on this, the data on which is read in by the steering column tube module control unit (N80) and supplied via the chassis CAN.

Upon reaching a speed threshold of v = 10 km/h the display of the pictures recorded by the Night View Assist takes place in the Audio/COMAND display. The Night View Assist camera transmits these via digital video interface (Low Voltage Differential Signal (LVDS)) to the Night View Assist control unit. The Night View Assist control unit receives the data from the Night view Assist camera and processes it further.

The Night View Assist camera operates like a conventional camera although with an extended Infrared light spectrum. The video picture is therefore also displayed when the infrared lamps are not activated.

The Night View Assist control unit filters out extremely bright areas of the image, which could blind the driver. This makes it easier for the driver to see the relevant content of the picture (e.g. obstacles, pedestrians or cyclists). The brightness distribution is processed in the night view assist control unit.

The front window must be permeable to infrared light in the field of view of the Night View Assist camera (possible disturbing influences would be: Blocking film, black print, adhesive labels, stone chipping, icing up or dirt).

The Night View Assist control unit transmits the processed data via an analog video interface to the COMAND controller unit COMAND (A40/3) with the information on brightness (Luminance) and color (Chrominance). From here data is transmitted via the LVDS line to the Audio/COMAND display.

The picture cutout shown and the brightness on the Audio/ COMAND display can be adjusted via the left multifunction steering wheel button group (S110) and right multifunction steering wheel button group (S111).
The signals from the multifunction steering wheel button group are read in by the steering wheel electronics (N135) and transmitted via the steering LIN (LIN E1) to the steering column tube module control unit (N80) which provides the signals on the chassis CAN. The front SAM control unit SAM passes these on via the interior CAN (CAN B) to the COMAND controller unit.
If the Night View Assist system identifies individuals in the field of view of the Night View Assist camera during night mode, they are shown with highlighted edges in the Audio COMAND display.

For this it has to be defined whether the vehicle is in a town or on an unilluminated country road.
This is accomplished by evaluating the data from the multifunction camera (A40/11).
The multifunction camera differentiates between light sources originating from one's own vehicle and surrounding light sources (e.g. street lamps).

If the multifunction camera identifies light sources not originating from the vehicle in the vehicle surroundings, person detection is disabled.

Component Identification:

Caused by the system misinterpretations can occur, e.g. objects can be looked upon as people and are shown hightlighted with corners.
The recognition rate decreases with increasingly unfavorable conditions (e.g. strong opposed light, rain, snow, bright background or people wearing very dark clothing and people are not shown highlighted.

After replacing the front window, a component of the Night View Assist system or removal of the Night View Assist camera, the Night View Assist camera must be recalibrated.

The display of the data recorded by the Night View Assist camera in the Audio/COMAND display is disarmed under the following conditions:
- Exceeding or falling below the vehicle speed range
- engaging the reverse gear

The "reverse gear engaged" status is defined as follows.

Vehicles with transmission 711, 716:
Engagement of reverse gear is defined via the status of the backup lamp switch (S16/2) which is read in directly by the front SAM control unit SAM. The front SAM control unit generates the status "Reverse gear engaged" and transmits this via the chassis CAN to the Night View Assist control unit.

Vehicles with transmission 722.6:
The request Engage gear range "R" is defined by the respective selector lever position and is output by the electronic selector lever module control unit (N15/5) via the drive train CAN (CAN C).
The CDI control unit CDI (N3/9) (on diesel engine) or ME-SFI control unit (N3/10) (on gasoline engine) reads in the status of the selector lever position and und passes this on via the chassis CAN to the Night View Assist control unit.

Vehicles with transmission 722.9:
The status of the current selector lever position is sent by the intelligent servo module for DIRECT SELECT (A80) via the drive train CAN and passed on further by the CDI control unit or by the ME-SFI control unit via the chassis CAN to the Night View Assist control unit.