Navigation mode, function

S82.85-4601-79

Function requirements for navigation mode in general

 Status circuit 30g ON

 Transport mode not active

General navigation mode

The navigation module is integrated in the radio (Audio/COMAND). The navigation system includes the following functionalities:

 Position finding

 Destination entry

 Route calculation

 Display of navigation maps

 Intersection zoom

 Visual driving instructions in form of pictograms

 Acoustic driving instructions

 Route types:

 "Fast route"

 "Dynamic route"

 "Eco Route"

 "Short route"

 Route options, e.g.: 

 "Use toll roads"

 "Use vignette roads"

 "Avoidance options"

 "Avoid freeway"

 "Avoid tunnels"

 "Avoid ferries"

The navigation system can be activated using the "NAVI" button on the upper control panel (UCP) control unit. The upper control panel (UCP) control unit forwards the control signals to the radio (Audio/COMAND) via the following route:

 Telephone keypad LIN

 Audio/COMAND control panel

 Telematics CAN

The navigation system can be operated as follows:

 With the Audio/COMAND control panel.

The control signals are transmitted from the Audio/COMAND control panel to the radio (Audio/COMAND) via the telematics CAN.

 With the touchpad control unit.

The control signals are sent from the touchpad control unit over the telematics CAN to the radio (Audio/COMAND).

 Via the voice control system integrated in the radio (Audio/COMAND).

 With the controls of the left multifunction steering wheel button group and the right multifunction steering wheel button group.

The control signals of the multifunction steering wheel button groups are forwarded to the radio (Audio/COMAND) via the following route:

 Steering wheel electronics

 Steering LIN

 Steering column tube module (MRM) control unit

 Chassis CAN

 Central gateway (CGW)

 User interface CAN

 Explanations:
Secure Digital card = SD, Global Positioning System = GPS, Universal Serial Bus = USB

The navigation function consists of the following subfunctions:

 GPS position finding

 Basic position finding

 Calibration

 Recalibration

 Route calculation

 Destination-oriented navigation

 Dynamic route guidance

 Map function

 Extended navigation functions

 Voice control system

General information on GPS position finding

GPS position finding is irretrievable after vehicle transport (e.g. by train or ferry or after towing). A new GPS position finding process (after interruption of satellite reception) can take several minutes (up to 5 min. on initial commissioning).

Additional function requirements for GPS position finding

 Signals available from at least three GPS satellites.

GPS position finding function sequence

The GPS receiver in the radio (Audio/COMAND) receives the GPS signals from the GPS antenna. The radio (Audio/COMAND) uses the GPS signals to calculate the current position of the vehicle.

 As GPS operates in the gigahertz (GHz) range and the signals are weak, the following events may lead to reception interference: Atmospheric interference disturbances (e.g. bad weather, water vapor, mist), multiple reception through signal reflexions (e.g. on house walls) or signal shadowing (e.g. in built-up areas, in tunnels, due to tall buildings or trees).

General information on basic position finding

Navigation can be continued without a GPS signal using basic position finding. A defect, e. g. in the GPS antenna is therefore not immediately perceptible.

Basic position finding runs parallel to GPS position finding. For basic position finding, the radio (Audio/COMAND) requires the following information:

 Wheel speed and wheel rotation direction (forwards or backwards)

 Gyro sensor (rotational angular velocity)

 3-D acceleration sensor (ramp detection)

Basic position finding function sequence

For basic position finding, the radio (Audio/COMAND) requires signals from the following components:

 Electronic Stability Program (ESP) control unit (wheel speed signals including direction of travel)

 Gyro sensor (turn rate sensor), integrated in the radio (Audio/COMAND).

 3D acceleration sensor, integrated in the radio (Audio/COMAND)

The radio (Audio/COMAND) receives the data from the Electronic Stability Program (ESP) control unit via the following route:

 Vehicle CAN

 Central gateway (CGW)

 User interface CAN

The data from the sensors integrated in the radio (Audio/COMAND) is forwarded inside the radio (Audio/COMAND).

 Location errors during position finding, rolling backwards with "circuit 15 OFF" (ignition switched off) or transport of the vehicle falsify basic position finding. The deviation is automatically corrected by the navigation processor integrated in the radio (Audio/COMAND) when GPS data are received.

Calibration

The calibration following a tire replacement is performed automatically.

Recalibration

Because of the tire abrasion, a constant recalibration of the tire circumference is required.

Route calculation

Route calculation is accomplished using the options set to the best possible extent. If observance of the options is not possible, then the options set are ignored for the sections in question and a message is displayed and signaled audibly.

Route guidance function sequence

The integrated navigation processor continuously compares the route calculation data with the position finding data and uses the data to deduce measures for further route guidance. Route guidance is subdivided into the following areas:

 Map route guidance

 Route guidance through driving lane recommendations

 Route guidance by means of voice output

Map route guidance

Signals for visual depiction of the route guidance (map navigation) are generated by the radio (Audio/COMAND) and sent to the Audio/COMAND display control unit via an LVDS line. The Audio/COMAND display control unit is switched on by the radio (Audio/COMAND) via the telematics CAN.

Route guidance through driving lane recommendations

For certain turnoff situations on multiple-land exit points (e. g. freeway intersection) driving lane recommendations are shown in the bottom line.

The following colors are used in the Audio/COMAND display control unit:

 White: Denotes the best or recommended lane.

 Light gray: the lane is correct, but a lane change will soon be required.

 Dark gray: this lane will not take you to the destination.

 The instrument cluster (IC) control unit only displays the white arrows.

Route guidance by means of voice output

The route guidance of the navigation system is supported by voice outputs with the following information:

 Directional instructions

 Name of the next road to turn into.

Additional voice messages are output e.g. at the start of route calculation, when an intermediate destination is reached or when the destination is reached.

In some cases, special information is also issued via voice output in certain circumstances, e. g.:

 Destination lies in area where driving is only possible to a limited extent

 Route via ferry

During voice output, the navigation processor of the radio (Audio/COMAND) links word segments to form complete instructions or information.

The voice outputs are forwarded from the radio (Audio/COMAND) to the speaker system.

The volume of the voice output can be adjusted during voice output using the volume control button in the right lower control panel (LCPR) control unit. The radio (Audio/COMAND) receives the control signal from the right lower control panel (UBFR) control unit via the following route:

 Telephone keypad LIN

 Audio/COMAND control panel

 Telematics CAN

General information on dynamic route guidance

There are different types of dynamic route guidance:

 "Dynamic route"

 "Dynamic route with confirmation"

 "Eco Route"

During dynamic route guidance the current traffic situation is taken into consideration when appropriate traffic data is received.

During dynamic routing with confirmation, the user is notified of the effects of the route change on the travel distance and driving time. The route is only changed with the user's agreement.

A distinction is made between the following variants of dynamic route guidance:

 Dynamic route guidance without valid subscription for real time traffic data

 Dynamic route guidance with real time traffic data

Function sequence of dynamic route guidance without valid subscription for real time traffic data

The incoming information on the traffic situation can be received by the radio data system (RDS)/Traffic Message Channel (TMC) function via FMradio.

The FM receiver in the radio (Audio/COMAND) receives the traffic messages via FM 1 via the following route, and forwards them to the traffic data recorder in the radio (Audio/COMAND):

 FM/AM antenna

 FM/AM antenna amplifier

The FM receiver in the radio (Audio/COMAND) receives the traffic messages via FM 2 via the following route, and forwards them to the traffic data recorder in the radio (Audio/COMAND):

 FM antenna

 FM 2, DAB antenna amplifier

In vehicles with code E1D (Digital radio), the incoming traffic situation information can be received through the RDS/TMC function via the digital radio (DAB). The DAB control unit receives the DAB signals via the following route:

 FM antenna (DAB 1)

 FM 2, DAB antenna amplifier (DAB 1)

The DAB control unit forwards the signals to the radio (Audio/COMAND) via the MOST bus.

Additional function requirements of dynamic route guidance with real time traffic data

 With CODE EY2 (Live Traffic Information)

 Subscription for real-time traffic data

 When the subscription has expired, only dynamic route guidance with TMC messages via RDS is available.

Function sequence of dynamic route guidance with real time traffic data

The HERMES control unit receives the real time traffic data via the integrated communications interface, and forwards them via a USB connection to the radio (Audio/COMAND), where they can be used by the integrated navigation processor.

The HERMES control unit receives cyclic position data from the radio (Audio/COMAND) via the USB line. The HERMES control unit transmits the position data via the integrated communications interface to the service provider. In this way, the HERMES control unit contributes to collecting the traffic information, from which the dynamic route guidance then benefits in turn.

Map function

Map display is always controlled by the radio (Audio/COMAND). The following display functions are supported:

 Route guidance map

 Positioning map

 Route map

 Scrollable map

 Destination entry map

Extended navigation functions

The navigation system is extended with regard to convenience, customization and tourist information by the following functions:

 Integration of electronic travel guide, establishment of a destination collection, and route download via an SD card and the SD card slot of the multimedia connection unit

 Special search engine that also makes fuzzy destination entries possible (e. g. parts of destination town, road or points of interest).

 "Route flight" (provides a visual overview of the planned route from a bird's eye view)

 "Drive Show" (sequence of pictures, which show the current position, route, traffic information along the route, vicinity of the destination and the altitude course of the route currently being navigated)

 "Compass" (display of a compass screen, which also contains the geo-coordinates for the current position and the current altitude)

 Possibility to access the Mercedes-Benz "Travel guide" (accessory) via the SD card slot in the multimedia connection unit

Data exchange between the radio (Audio/COMAND) and the SD card takes place via the USB connection between the radio (Audio/COMAND) and the multimedia connection unit.

The extended navigation functions are implemented internally in the radio (Audio/COMAND), and - where applicable - shown via the LVDS line on the Audio/COMAND display.

Voice control system, general

Functions of the driver information system can be called up and operated via the voice control system (VCS). The voice control system is integrated in the radio (Audio/COMAND). The voice commands can be issued by spelling out or entering complete words.

Voice control system

The voice inputs via the hands-free system microphone are read in directly by the overhead control panel control unit (OCP) and forwarded.

The VCS is switched-on on the right multifunction steering wheel button group and switched off on the left multifunction steering wheel button group.

The control signals of the multifunction steering wheel button groups are forwarded to the radio (Audio/COMAND) via the following route:

 Steering wheel electronics

 Steering LIN

 Steering column tube module (MRM) control unit

 Chassis CAN

 Central gateway (CGW)

 User interface CAN

The radio (Audio/COMAND) receives the voice inputs via the following route:

 SAM control unit

 Vehicle CAN

 Central gateway (CGW)

 User interface CAN

The radio (Audio/COMAND) forwards the voice outputs to the speaker system.

The control signal is forwarded by the lower control panel control unit to the radio (Audio/COMAND) via the following route:

 Telephone keypad LIN

 Audio/COMAND control panel

 Telematics CAN