GF82.85-P-2012RTE Navigation Mode, Function
GF82.85-P-2012RTE Navigation Mode, Function
- with CODE (527) COMAND APS with single DVD drive (with navigation)
- except CODE (498) Japan version
- except CODE (494) USA version
The navigation system is intended to support the driver in finding the correct route and increase the driving safety in unfamiliar areas.
The primary navigation system functions include:
^ Position determination
^ Route planning
^ Route calculation
^ Destination-oriented navigation
^ Optical driving instructions according to pictograms and/or map displays
^ Acoustic driving instructions
All systems required for navigation, with the exception of GPS antenna (A2/93a6) are located in the COMAND operating, display and control unit (A40/3).
The GPS antenna integrated in the roof antenna module (A2/93) receives the GPS signals of the satellites and forwards them to the COMAND operating, display and control unit.
Important data on the specific vehicle, such as
^ the wheel pulse signal and
^ the backup signal
are sent digitally to the COMAND, operating, display and control unit over the Control Area Network bus, class B (interior compartment) (CAN-B).
Component Identification:
Function requirements
^ Startup
The COMAND operating, display and control unit can be activated by circuit 15R. After placing the navigation DVD in the drive slot in the COMAND operating, display and control unit, the navigation compares the software version already installed with the software present in the DVD. If the DVD contains a newer version of the software, it is loaded by the navigation unit.
Simultaneously, the GPS receiver is initialized in the background. These procedures can require up to approx. 15 minutes.
After successful initialization of the GPS receiver, the navigation unit begins with automatic calibration while driving.
It is no longer necessary to enter the tire parameters or perform a calibration drive. After driving approx. one kilometer, with a number of turns, the navigation unit is automatically calibrated. After successful startup, the navigation system in the vehicle is activated over circuit 30. The navigation DVD can then be removed or remain in the drive. However, the navigation DVD is read in each time the system is started up.
^ Switching off navigation
When the COMAND operating, display and control unit is switched off (ignition "OFF"), the navigation unit stores important data such as the last position, direction etc. in a volatile memory in order to avoid any new initialization process. Finally the COMAND operating, display and control unit switches for a maximum 72 hours into a sleep mode.
During this time, all navigation data in the navigation computer's memory are maintained. If within the 72 hours the COMAND operating, display and control unit is not switched on, it is almost fully switched off for safety reasons (for the on-board electrical system).
Consequentially, all data for navigation are lost.
In such an instance, when starting the COMAND operating, display and control unit, the navigation system has to reboot the operating system, receive the missing GPS data and compare the data against the current road map. Therefore, it may take up to four minutes before the user receives the first drive recommendations.
Basic navigation
^ Position determination
Simultaneously with startup of the system, the navigation unit compares the GPS data supplied by the GPS antenna with the stored data for vehicle position, direction as well as with the map data. The position of the vehicle is then determined with an accuracy of approx. 10 m by this procedure.
If the vehicle position is requested from the COMAND operating, display and control unit, the position is indicated on the map on the color display. Display in the form of longitude and latitude is also possible.
^ Destination address entry for route calculation
The following information can be used for entering the address:
- Town name
- Road
- Intersection
- House number (according to data availability)
- Town centers
- Town districts with street index (depending on data availability)
- Country
- Destination entry via map (using cross-hairs, which can be moved with the eight-way adjuster)
- ZIP code
Entry with an intelligent speller (letter and number field) is supported by the system. Depending on the process of the entry, only those characters are made available that can be entered next. Unique names can be completed automatically, where possible.
The limitation of the selection possibilities for characters also includes special symbols. Direct entry of a number is possible for the street number. Depending on the degree of digitization, however, the number or the corresponding house number area is selected.
When entering town centers without district boundaries, the main town is also provided as information.
^ Route calculation
After entering or calling up a destination, route calculation starts and an acoustic information is emitted: "Route is being calculated". In addition, an animated CD/DVD symbol is displayed during route calculation.
The route between the instantaneous vehicle position and the destination is calculated in the navigation processor.
The following calculation models can be selected:
- fastest route,
- shortest route and
- most dynamic route.
In addition, "Avoid options" can also be selected by the user and taken into consideration in calculating the route. These options include avoiding items such as ferries, tunnels and toll roads.
Route calculation can be additionally influenced through the input of a so-called VIA point and/or an intermediate destination/stop.
After successful calculation, the CD/DVD symbol disappears and the route is displayed on the map.
Following successful route calculation, the navigation DVD can be removed from the disk drive slot. This means that it is possible to listen to an audio CD during the navigation process. In this case, pictograms are used for display on the instrument cluster.
^ Journey on the calculated route
The actual position is compared cyclically in the navigation processor with the predicted position. The input parameters include the data from the yaw rate sensor (GYRO), integrate in the COMAND operating, display and control unit and the route data emanating from the vehicle. If the vehicle is moving on the precalculated route, all of the necessary information is communicated to the driver visually on the display and acoustically via the vehicle speakers.
This information includes:
- Destination
- Calculated arrival time and driving time
- Route mode (fast route, short route, dynamic route)
- Rout list
- Traffic message channel (TMC) (for ECE only)
This function terminates upon reaching the destination.
^ Leaving the calculated route
If the vehicle is no longer moving on the precalculated route, the route is recalculated.
If the recalculated values are plausible, the modified route is shown:
If the vehicle is on a road, which is present in digital form but for which no supplementary information is available such as one-way street, highway, etc., then the display "OFF ROAD" appears.
- If the vehicle is located outside of the digitized map area, the display "OFF MAP" appears.
Special destinations, POI (Points of Interest)
POIs can be selected according to the following criteria:
^ Position surrounding area
^ Surrounding area for last destination
^ Surrounding area for any town center (other town)
^ National destinations
The search radius for a POI in a category is generally approx. 20 km, however, special categories, e.g. airports, have a nationwide search radius.
^ The following POI categories are defined (depending on degree of digitization and national version):
- Exhibition site
- Highway exit
- Highway intersection
- Highway service
- Recreation area
- Car hire
- Railroad station
- Bank
- Bowling center
- Bus station
- Shopping mall
- Ferry
- Airport
- Golf course
- Border
- Hotel
- Cinema
- Hospital
- MB authorized workshop
- Museum
- Nightlife
- Public facility
- Parking area
- Police
- Post office
- Highway rest stops
- Restaurant
- Point of interest
- Other destinations
- Sports facilities
- Private airplane airfield
- Sports ground
- Filling station
- Theater
- Underground garage
- Tourist information
- Vineyard
Destination memory
Entered destinations can be filed manually in the address book.
If when selecting a language, the destination was additionally assigned a language tag, then this is also stored in the address book and used again.
All destination entry methods are available for making entries into the memory.
A maximum of 200 entries can be stored.
Last destinations
The user can call up a list of the last entered destinations and memory points in the main navigation menu. Memory points are points which are passed along a route.
With the start of destination-oriented navigation, the destination address is automatically filed under "Last destinations" in the memory. Up to fifty entries can be stored in the memory. When the memory is full, entries are automatically deleted according to the "first come first delete" principle. This means that the entry at position 50 will be deleted first. Entries can also be deleted manually by the user.
Voice output
^ The following languages are available:
- German
- British English
- French
- Spanish
- Italian
- Dutch
^ Voice outputs are given for:
- Turn-off recommendations
- Numbered roads (restricted to highways and Federal highways in Europe)
^ A special instruction for areas is given with:
- Destination not accessible by vehicle
- Destination in area accessible to limited extent on
- Route via ferry
- Route vie toll road
^ Further announcements:
- Start of route calculation
- Destination, intermediate destination reached
- General information (route influenced by traffic messages)
Compass
Shown in compass display:
^ Cardinal points via compass rose
^ Steering angle via vehicle display
^ Altitude via altitude scale
Route calculation
Route criteria and route options
The following criteria are available for route calculation:
^ Shortest route
^ Fastest route
^ Dynamic route (corresponds to fast route taking traffic messages into account)
These criteria can be restricted by the following options:
^ Avoid highway
^ Avoid toll road
^ Ferry, avoid vehicle loading
^ Avoid tunnels (visually notified)
Route calculation is accomplished using the option set to the greatest possible extent.
If observance of the options is not possible, the options set are ignored for the sections in question.
The set criteria and options can be displayed and changed at any time.
If an "avoid option" cannot be satisfied by the system, this is indicated visually to the user in a pop-up on the display on the COMAND operating, display and control unit.
Route planning
The navigation system differentiates between main destinations and intermediate stops on a trip.
The primary destinations must be arrived at exactly in each case, before route planning can be accomplished to the next destination. If, however, a main destination is entered together with an intermediate destination, the navigation system divides the route up into two sections and first guides the user to the intermediate destination (or intermediate stop) and then automatically to the desired main destination.
VIA destinations are treated by the navigation system as "soft" destinations along the actual route. This means that VIA destinations are incorporated into the route calculation for the actual main destination and not treated as second destination.
Remaining driving time and remaining driving distance
The distance from the vehicle position to the next destination and the estimated driving time are shown.
The driving time is calculated from the speed which is allocated to the stretches still to be traveled.
Additionally, when traveling stretches that are affected by a traffic message, extra driving time is included in the calculation.
Station selection for dynamic destination-oriented navigation
For dynamic destination-oriented navigation, a TMC Location Table (TMC = Traffic Massage Channel) for the country present on the data medium is maintained. A prerequisite for this is that corresponding information about this country is available.
The information as to whether TMC Location Tables are available or not, is made available to the TMC data source, so that a station source selection can be made and the filtering of traffic messages is done as close to the source as possible.
Dynamic traffic messages can be shown on the map as an icon and additionally as text message.
If shown as text, the messages are sorted according to country and highway in question.
Traffic reports relevant to the route are, for example:
^ Completely blocked
^ Jam
^ Stop and go traffic
^ Heavy traffic
Manual block
Manual blocks can be specified for a distance to the start of a traffic jam (traffic jam ahead) up to max. 10 km.
It is only possible to block out a portion of the route in the vicinity of the current location, not the entire route, depending on the distance to the destination.
Similarly, a block can also be canceled independently.
Navigation
Displays of driving recommendations are always made taking the following into consideration:
^ current speed,
^ current type of road and
^ distance to decision-making point.
Depending on the given situation, driving recommendations are made in up to three stages:
^ Preliminary announcement (dependent on current class of road)
^ Approach
^ Action
Symbolic driving recommendations
A pictogram may be displayed depending on the turning situation. A symbolic driving recommendation is generated for each decisive point. A distinction is made between the following situations:
^ Follow course of road ("Follow")
^ Advance announcement ("Prepare")
^ Turn off at an intersection (all intersecting roads are indicated and illustrated with a direction resolution of 30�)
^ Exit at an exit (with a direction resolution of 90�)
^ Rotary intersection, right-hand/left-hand traffic (all exits in rotary intersection are given, in fully digitized areas only)
^ Fork in road (with direction resolution of 30�)
^ New route calculation
^ Turn around, right-hand and left-hand traffic
^ Destination direction for route calculation (Off-Road, Off-Map and No-Route)
Longitude details
The distance to the next turning point is indicated when the action is within the vicinity of the route search. Additionally, a turn-off recommendation is indicated by a bar graph.
Street names and signs
The following information is available:
^ Name of street current being traveled on
^ Name of the road to turn into
^ On highways: direction indicator with information on number of exit, number of road, name of town in main direction or federal highway
During destination-oriented navigation, driving recommendations can be displayed in the so-called split-screen mode.
Split screen
This feature allows the user to have driving recommendations displayed in an enlarged window, the map display being less detailed. The current vehicle position, route and turning points are displayed.
Dynamic adjustment
Dynamic adjustment is based on the RDS/TMC functionality.
The data contents are adopted from the definition of TMC events. The use of TMC data can be activated or deactivated in the navigation system via the "Dynamic route" option.
The TMC data are adopted from the FM signals (radio messages with RDS/TMC).
The audio gateway integrated into the COMAND operating, display and control unit is a 2-tuner receiver. For TMC reception, a background tuner is primarily used. It scans continuously for receivable TMC stations and saves the received TMC messages in a TMC table, which is then sent to the navigation system.
The navigation system checks all messages in terms of route relevance. All TMC messages from all receivable TMC sources are thus taken into consideration. Several TMC tables can be loaded at one and the same time; generally, two are loaded.
For international routes, the foreign route-relevant TMC messages can also be considered and displayed. For this reason, the messages are sorted according to country and highway.
VIA points
When using the detour (VIA) point option, the route is calculated to the next destination taking a transition point into consideration.
The VIA point is not an actual destination and need not be actually driven to. It merely serves the route guidance as an orientation point for route calculation.
Entry of a VIA point is done starting in the VIA menu of the COMAND operating, display and control unit, by the user selecting the desired VIA point from a VIA list.
One VIA point each can be defined between the current location and the next destination.
