Electrical function schematic for 360 degree viewing system - GF54.65-P-0007FQM

MODEL 218 as of model year 2015 with CODE 501 (360 degree camera) 

Function requirements, general 

• Terminal 15 ON
• Vehicle speed v < 18 km/h

The status of circuit 15 is sent by the electronic ignition lock control unit via the chassis CAN 1, front SAM control unit and chassis CAN 2 to the parking system control unit.

The vehicle speed is calculated from the wheel speed. The Electronic Stability Program control unit sends corresponding information via chassis CAN 1, front SAM control unit and chassis CAN 2 to the instrument cluster. The instrument cluster calculates the vehicle speed to be displayed and sends this over chassis CAN 2 to the 360° camera control unit for calculating the switch-off behavior.

360° camera system, general 

The 360° camera system consists of four digital cameras. One camera each is located behind the radiator trim, the outside mirror housings and the trunk lid (in model 218.3) or on the liftgate (in model 218.9). The 360° camera control unit uses the picture data from the cameras to calculate a virtual picture ("Virtual viewpoint"). On the Audio/COMAND display, the vehicle and its surroundings (s = 3 m to front and rear and s = 2.5 m on the sides as measured on the ground) are displayed as a "Vehicle top view" (bird's eye view).

A total of seven split views and two full-screen views of the vehicle surroundings can be displayed, but only two views can be displayed at the same time: the vehicle view "from above" and one detail view (e.g. the picture taken by the rear 360° camera after having engaged the "R" gear range).

Camera lenses with a horizontal angle of vision of ∠ > 180° and a vertical angle of vision of ∠ > 123° record the required field of view.

Dynamic and static guide lines, which represent the vehicle dimensions and driving trajectories (driving path) based on the steering angle, are displayed to assist the driver. With the help of these representations, the driver is provided assistance especially during parking and maneuvering. Additional elements are displayed here that mark the area at risk at the vehicle corners.

The 360° camera function comprises the following subfunctions:

• Function sequence for activating, deactivating the 360° camera system 
• Function sequence for picture recognition, picture output 

Function sequence for activating, deactivating the 360° camera system 

The 360° camera system can be manually activated or deactivated by pressing the "Sys" button in the COMAND controller unit for t > 2 s. By engaging gear range "R", the 360° camera system is automatically activated.

Activating/deactivating manually:

The COMAND controller unit reads in the status of the "Sys" button and sends the status of the 360° camera function via the interior CAN, front SAM control unit and chassis CAN 2 to the 360° camera control unit. The 360° camera control unit then activates or deactivates the 360° camera system.

Automatic activating/deactivating:

The automatic activation or deactivation of the 360° camera system must be enabled via the corresponding operating level of the COMAND controller unit. The Audio/COMAND control panel sends the corresponding control signals (softkey, favorite button) to the COMAND controller unit over the telematics CAN. The COMAND controller unit sends the status of the 360° camera function via the interior CAN, front SAM control unit and chassis CAN 2 to the 360° camera control unit. Once the gear range "R" is engaged, the 360° camera control unit activates the 360° camera system. Gear range "R" is engaged through the fully integrated transmission control unit. Subsequently, the fully integrated transmission control unit sends the status of the selector lever position to the 360° camera control unit via the drive train CAN, CDI control unit or ME-SFI control unit, chassis CAN 1, front SAM control unit and chassis CAN 2.

The 360° camera system is on after the gear range "R" is engaged.

When switching gear range from "R" or "D" to gear range "N", the previously shown picture continues to be shown in the Audio/COMAND display. When switching gear range to "P", the 360° camera system is automatically deactivated.

If an attempt is made to activate the 360° camera system above a vehicle speed of v = 18 km/h, an inactivity message appears on the Audio/COMAND display. When falling below this speed limit at a later stage, the 360° camera system is activated. An inactivity message will also be issued on the Audio/COMAND display if the 360° camera system is activated at a vehicle speed of v < 18 km/h and the vehicle speed increases to v > 18 km/h within t = 1 s.

During reverse travel, the 360° camera system operated independently from the speed.

During initial startup as well as after replacement of the 360° camera control unit or a camera or upon removal/installation of the trunk lid, or liftgate, an outside mirror or the radiator trim, the corresponding cameras must be recalibrated. After a camera is replaced, a recoding of the 360° camera control unit is required.

The following situations lead to a deactivation of the 360° camera function:

• Vehicle speed v > 18 km/h
• Circuit 15 OFF
• Selection of gear range "P"

Function sequence for picture recognition, picture output 

The pictures recorded by each camera are directly read in by the 360° camera control unit over low voltage differential signaling lines and processed. The 360° camera control unit calculates guide lines to be shown on the Audio/COMAND display taking into account the steering wheel angle, the wheel angle and stored vehicle parameters.

Additionally, the 360° camera control unit uses the information of the parking system, for example, to mark the areas of the vehicle corners at risk during maneuvering.

The 360° camera control unit sends the request for displaying the picture via the chassis CAN 2, front SAM control unit and interior CAN to the COMAND controller unit. This then activates the Audio/COMAND display via telematics CAN. The 360° camera control unit then transmits this processed picture data to the COMAND control unit via the low voltage differential signaling lines. The COMAND controller unit sends this to the Audio/COMAND display over the low voltage differential signaling (LVDS) line. There the processed camera pictures including the guide lines are then displayed.

For a better representation of the camera pictures, the 360° camera control unit corrects the pictures electronically for distortion.

The steering wheel angle is recorded by the steering wheel sensor. The steering column tube module control unit reads in the signals from the steering angle sensor directly and sends the steering wheel angle via chassis CAN 1, the front SAM control unit and chassis CAN 2 to the 360° camera control unit.

The Electronic Stability Program control unit calculates the wheel angle based on the position of both front wheels and sends corresponding information to the 360° camera control unit via chassis CAN 1, front SAM control unit and chassis CAN 2.

The parking system control unit sends information on the parking system to the 360° camera control unit via chassis CAN 2.

To ensure that the surrounding area can also be recorded in the dark, the ambient illumination in each of the outside mirror housings is activated, irrespective of the ambient brightness. For this purpose, the 360° camera control unit permanently sends the "Switch on ambient illumination" request via chassis CAN 2 to the front SAM control unit. The front SAM control unit as the exterior lights master control unit then evaluates the ambient brightness. When it is dark, the front SAM control unit sends a corresponding request to the left front door control unit and the right front door control unit over the interior CAN. They activate the ambient illumination in the outside mirror housings.

Detailed information about the "ambient illumination" can be found in the partial function "Headlamp switch-off delay (SWA), function" in the separate function description "Exterior lights, function".

The background illumination for the Audio/COMAND display can be manually adapted to the ambient brightness. The background illumination can be adjusted through the COMAND controller unit in the "360° camera" system menu function bar by choosing the "Sun" symbol.

Representation of vehicle views in the Audio/COMAND display:

The vehicle view "from above" also displays an open door and/or an open trunk lid. The rear SAM control unit sends the status of the trunk lid or the liftgate (open or closed) via the interior CAN, front SAM control unit and chassis CAN 2 to the 360° camera control unit. The status of the respective door (open or closed) is sent by the corresponding front and rear door control units via the interior CAN, front SAM control unit and chassis CAN 2 to the 360° camera control unit. The 360° camera control unit processes this information and correspondingly displays an open front door or an open trunk lid or an open liftgate in the vehicle view "from above". The picture data from the camera of the open door or the open trunk lid or an open liftgate are not displayed.

When the outside mirror housings are folded up, the areas on the side of the vehicle can no longer be recorded. The corresponding areas are also hidden in the Audio/COMAND display in this case. The status of the corresponding outside mirror housing is sent by the corresponding front door control unit to the 360° camera control unit via interior CAN, front SAM control unit and chassis CAN 2.

In the "Full screen forward field of view" and "Full screen rearward field of view" views, object recognition is active. In the area of maximum s = 250 cm, objects and pedestrians are recognized and marked by object detection lines (visual warning).

The 360° camera system is active during forward travel up to a vehicle speed of v = 30 km/h. When this speed limit is exceeded, the 360° camera system is deactivated.

Vehicles with code (489) AIRmatic (air suspension with continuous adjustment damping):

The current vehicle level is used by the 360° camera control unit to calculate and equalize the recorded pictures for optimum display in the Audio/COMAND display. Information on the vehicle level is sent by the AIRmatic control unit over the chassis CAN 1, front SAM control unit and chassis CAN 2 to the 360° camera control unit.

The following views are possible on the Audio/COMAND display:

• Vehicle top view and forward field of view
• Vehicle top view and rearward field of view
• Vehicle top view and field of view of front wheels on both sides
• Vehicle top view and field of view of rear wheels on both sides
• Vehicle top view and field of view for trailer hitch (with code (550) Trailer hitch)
• Full screen forward field of view
• Full screen rearward field of view
• Vehicle top view with enlarged view of vehicle front
• Vehicle top view with enlarged view of rear end of the vehicle

System limits:

The functions and representations of the 360° camera system are limited. Distortion and "blind spots" can occur.

In the vehicle view "from above", objects outside road level (e.g. vehicles) are displayed with distortion.

Objects in the "Full screen forward/rearward field of view" (the 360° camera at front and the 360° camera at rear are active) are also shown in distorted form. The assignment of objects in the picture to how they appear in real-life can therefore be unusual.

There are different types of "blind spots" depending on the system and model in question. One reason is the camera position over the respective bumper: Here, the camera loses the field of view immediately before and after the vehicle. On the other hand, they are system-related, particularly in the four overlapping areas of the fields of view of the cameras, when calculating a vehicle view "from above". Furthermore, due to the low installation height of the cameras, there are areas where only objects close to the ground can be seen. This means, for example, that people are not shown roughly above knee height in the vehicle view "from above". In both cases, however, support is provided by the parking system.

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