LEMON Manuals: Even more car manuals for everyone
Home >> Mercedes Benz >> 2009 >> E350 Base >> Repair and Diagnosis >> Accessories & Equipment >> Infotainment >> Entertainment, Navigation & Telephone -- Basic Knowledge -- E350 (211.256) >> Basic Knowledge >> Position finding and destination-oriented navigation, function - GF82.61-P-2010TJA

Position finding and destination-oriented navigation, function - GF82.61-P-2010TJA

MODEL 211, 219 with CODE (527) COMAND APS with single DVD drive (with navigation) with CODE (498) Japan version as of Model Year 9/AEJ 07 

Function requirements 

General information concerning position finding 

GPS is available worldwide. The GPS satellites permanently transmit time and position data (longitude and latitude). GPS position finding is irretrievable after vehicle transport (e.g. by train or ferry or after towing).

Basic position finding runs parallel to GPS position finding.

The position finding function consists of the following component functions:

Function sequence for GPS position finding 

The GPS receiver COMAND is integrated into the COMAND operating, display and controller unit. It receives the GPS signals from the GPS antenna (A2/49a2) over the following path:

The GPS signals are used by the COMAND operating, display and controller unit to calculate the momentary position of the vehicle (receiver). In addition, the vehicle's direction of travel is determined with the aid of the sequence of the locations calculated with GPS.

IMPORTANTPossible problems in GPS signal reception 

Since GPS operates in the Gigahertz (GHz) range (microwaves) and the signals are weak, reception interference can occur as a result of the following events:

Function sequence, basic position finding (dead reckoning) 

The COMAND operating, display and controller unit requires the following information for basic position finding:

The wheel speed signals are recorded by the following RPM sensors:

The wheel speed signals are transferred to the COMAND operating, display and controller unit from the RPM sensors over the following path:

The travel distance data is also determined from the wheel speeds.

The data for the vehicle orientation (change in angle) is processed internally by the turn rate sensor (gyro sensor) integrated into the COMAND operating, display and controller unit.

The data about the direction of travel (forward or backward) is received by the COMAND operating, display and controller unit via the CAN-B from the central gateway control unit.

The COMAND operating, display and controller unit then calculates the coupled position from the distance traveled and in consideration of the vehicle orientation and direction of travel. This coupled position is compared with the GPS data (longitude, latitude, direction). This position data is then compared with the map data (map matching). In order to detect the street level (overpass) the vertical angle (by the 3D gyro) and the information from the Electronic Toll Collection (ETC) gates are taken into consideration.

IMPORTANT Error during position finding

Basic position finding is falsified when a vehicle rolls backwards with "circuit 15 OFF" (ignition switched off) or if it is transported somewhere. In both cases, the deviation is automatically corrected by the navigation processor integrated in the COMAND operating, display and controller unit, provided GPS data are received.

Destination-oriented navigation function sequence 

The destination-oriented navigation consists of the following subfunctions:

Function sequence for destination-oriented navigation through voice output 

IMPORTANT In vehicles with code 810 Sound system, the voice output is effected by the COMAND operating, display and controller unit via the Media Oriented System Transport (MOST) to the sound system amplifier (N40/3) and from there to the front speakers via direct lines.

Destination-oriented navigation function sequence through visual display 

The signals for visual representation of the destination-oriented navigation (map navigation) are generated by the COMAND operating, display and controller unit and indicated on the display on the COMAND operating, display and controller unit.

The integrated navigation processor continuously compares the route calculation data with the position finding data and uses the data to deduce measures for further destination-oriented navigation. The destination-oriented navigation voice output is emitted over direct lines to the following speakers:

VICS function sequence over FM multiplexer 

The driver is provided with vital information by the VICS on the current traffic situation. Traffic impairments and traffic jams are shown on the map, however they are not incorporated into the dynamic route guidance. The radio antenna signal path is as follows:

The VICS information is edited in the FM multiplexer integrated into the COMAND operating, display and controller unit. The information is then shown on the display on the COMAND operating, display and controller unit. In addition, the FM multiplexer can also receive additional information, e.g. on the weather or earthquakes.

COMAND operating, display and controller unit, component description   GF82.85-P-3134TJA
Sound system amplifier, component description with code 810 Sound system GF82.62-P-6003TM 
Speaker system, component description Model 211 GF82.62-P-4220TM 
  Model 219 GF82.62-P-4220TXB
Hands-free system microphone, component description Model 211 GF82.70-P-4121TM
  Model 219 GF82.70-P-4121TXA
scientia non olet · About LEMON Manuals