New Range Rover Navigation System
New Range Rover Navigation System
Introduction To The Global Positioning System (GPS)
The system used to calculate the current position of the vehicle is called the global positioning system (GPS). The system utilises satellites which are owned by the United States Department of Defence (DOD). A total of 24 satellites circular orbit the earth every 12 hours at a height of 20,000 km (12500 miles) and between 5 and 11 of these satellites can be seen from a single point at any given time. The orbits are tilted to the earth's equator by 55 degrees to ensure coverage of polar regions. Each satellite transmits radio signals to provide information about the satellite position i.e. latitude longitude altitude almanac data and an accurate time signal generated by an on-board atomic clock. Each satellite contains tour atomic clocks
The vehicle needs to receive data from at least four different satellites to give a three dimensional fix on its current position.
As the vehicle moves, this information is continually being updated. The computer determines which satellites are 'visible' to the system and their current position and relationship to each other. Using this information the computer can account for positional deviations of the satellites and compensate to enhance the accuracy of the navigation system.
The GPS signal is also known as the Precision positioning signal (PPS). This is now the only GPS signal available, since the Selective positioning signal (a deliberatly degraded signal) was turned of on the 2nd May 2000. The ensures that everyone can now use the higher accuracy available with PPS
SPS predictable accuracy was:
- 100 metres horizontal accuracy
- 156 metres vertical accuracy
- 340 nanoseconds time accuracy.
PPS predictable accuracy is
- 22 metres horizontal accuracy
- 7.7 metres vertical accuracy
- 200 nanosecond time accuracy.
Each navigation system provides computer generated audible and visual route guidance information to enable the driver to reach a desired destination. The system allows the driver to choose the desired route using minor or major roads or motorways and the quickest or shortest route. Directions to hospitals, museums, monuments and hotels are also available. The computer uses map information stored on a CD-ROM to determine the best route for the journey and provide the driver with details of directions and approaching junctions.
The system uses almanac data to determine the vehicles position. Almanac data is the current status of the 24 satellites which orbit the earth. The computer determines which satellites are 'visible' to the system and their current position and relationship to each other. Using this information the computer can account for positional deviations of the satellites and compensate to enhance the accuracy of the navigation system. The navigation system requires the almanac data from at least four different satellites to calculate a three dimensional 'fix' on its location. As the vehicle moves the computer continually up dates this information so that at all times the computer knows the precise location of the vehicle.
New Range Rover Navigation System
New Range Rover navigation system provides on road navigation capabilities. On road navigation requires a CD based map to be inserted in the navigation computer. One map disc is supplied with the vehicle, subsequent updated discs can be obtained from Land Rover dealer-ships at additional cost. Discs are available for different countries and if road navigation is required whilst traveling abroad map discs will need to be changed for appropriate discs.
Navigation System Components
New Range Rover Satellite navigation system comprises the following components (except Japan):
- Multi-Function Display
- Navigation computer
- GPS antenna.
The Japanese navigation system comprises:
- Navigation computer
- GPS antenna
- GPS receiver
- VICS Receiver
- VICS antenna.
Navigation Computer
The navigation computer is located in the left hand side of the luggage compartment. The computer is the main component in the navigation system and receives inputs from the Body Control Unit (BCU) and the GPS antenna. The navigation computer contains a solid state piezo gyro which measures the motion of the vehicle around Its vertical axis. The gyro operates on the principle known as the Coriolis force. The Coriolis force is the force that appears to accelerate a body moving away from its rotational axis against the direction of rotation of the axis.
Using the Inputs from the BCU, the GPS antenna and the gyro sensor, the computer calculates the vehicle's current position direction and speed.
The navigation computer also houses the CD-ROM drive. The drive is used to read map data from country specific CD's and also to load updated software into the computer. A button located adjacent to the CD slot is provided to eject the CD from the unit. If ignition is on, one press of the button will eject the CD. If the Ignition is off, two presses are required one to wake up the system and the second to eject the CD.
Previous Range Rover navigation systems used a separate navigation receiver this version integrates the receiver within the navigation computer. The GPS receiver receives information from between 1 and 8 satellites at any one time. This information is received from the GPS antenna. The built in GPS receiver the following functions:
- Calculation of position (i.e. Latitude longitude and height), direction and speed
- Collection and storage of almanac data
- Real-time clock.
The navigation computer uses non-volatile memory to store settings and configuration information when it is powered down. This process takes place just before the computer turns off and occurs approximately one minute after all K- Bus activity has ceased. Once the power down sequence has been completed, the red LED on the front of the unit is extinguished.
If the unit is disconnected before the LED goes out the computer could fail to complete its data storage This will cause the unit to become unusable and it must be replaced.
For the Japanese market the navigation computer is a different component. Although it looks identical the unit houses a DVD drive and the internal receiver is replaced by an external one. The system also has extra components for the VICS system (a receiver and an antenna). The VICS system receives allows the vehicle to receive information about traffic conditions from roadside transmitters and adjust the navigation instructions accordingly. The VICS information is received by both a radio link and an infrared link. For this reason the antenna is located behind the rearview mirror on the inside of the windscreen.
VICS Antenna
VICS Receiver
GPS Antenna
The GPS antenna is located in the rear spoiler on the upper taildoor of the vehicle. The antenna is connected to the navigation computer via a single co-axial cable and passes signals received from the GPS satellites to the built in receiver for processing.
It is possible for the antenna to lose the signals from the satellites in hilly or tree lined areas, built up areas with tall buildings multi storey car parks , garages tunnels bridges and during heavy rain/thunderstorms. When the signal is lost, the navigation computer will continue to give guidance using memory mapped data from the CD map until the signal is restored.
Multi-Function Display
The Multi-Function Display (MFD) is the user interface for the navigation system. The MFD is also the interface for the radio cassette CD charger trip computer and telephone functions of the audio system along with the auxiliary heating timer control DSP functions television and teletext. The unit comprises a wide screen format LCD monitor and associated control buttons. The unit houses a cassette mechanism hidden behind the screen which tilts down to load/ eject the cassette.
Multi-Function Display Cassette Slot
The MFD communicates along the K-Bus with the navigation computer the CD multi changer (where fitted) the radio unit, the telephone (where fitted, the instrument pack and the video module. The communication with the instrument pack is used for diagnostic communication via the CAN Bus.
Multi-Function Display Controls
Navigation System Operation
The navigation system is operated entirely from the MFD. The following describes the operation of the navigation system and assumes there is a correct map disc in the computer and that the ignition is in position II.
Entering a Destination
From the main menu screen select the GPS navigation option using the right hand rotary controller (turn to highlight press to select).
Main Menu
This brings up the input destination screen.
Input Destination
If the name of a country appears on the monitor in white letters data for more than one country is stored on the map CD. Using the rotary controller the country can be selected (if desired/possible) in the usual manner.
Once the correct country has been selected the destination city can be selected.
Input Road
Use the rotary controller to select the first letter of the city. The computer will bring up the first city in its database that has that letter as its first. If this is the correct city use the rotary controller to highlight the enter button to select the city. If however the city is not correct, select the next letter. This process is repeated until the city name is completed in full. Once the city name is correct select the enter button and press store to store the destination city.
Next the road has to be input followed by the house number. This is done in exactly the same manner as the city was input.
Guidance to Destination
Once the complete destination address has been the city, road and house number are displayed on the monitor; "Dest' guide" is highlighted.
Destination Guide
Press the right-hand rotary control to start destination guidance. While the navigation computer is calculating the route to the destination, the distance and direction to the destination as the crow flies are displayed at the top right hand corner of the screen.
Once the route has been calculated, the destination address that has been entered appears at the top left hand corner of the screen. The name of the road which the arrow instructs you to turn into is shown below it together with the distance to the junction with that road. A change of direction is likewise indicated by the spoken instructions.
The distance to the next turning is shown at the top right hand corner of the screen. An arrow indicates the direction of the chosen destination as the crow flies. Your current position is shown at the bottom left: hand corner of the screen.
Should the area travelling through not be fully covered by the map CD, the arrow will display the direction in which the driver should be travelling.
To repeat an audible instruction use the rotary controller to highlight the instruction button and press.
Once programed with a route it is not necessary for the display to stay on the navigation system. The radio cassette or CD player can all be used. The navigation display and audible guidance will warn the driver prior to the next junction/direction change.
Route Display
Selection of the route display option will call up the route display screen. This screen displays a map view of the route to be driven along with an icon on the route show the vehicles current position on the route.
Navigation System Diagnostics
Information can be accessed through the diagnostic line using TestBook/T4 on both MFD and MID systems. Information which can be accessed includes the following:
- Land Rover part number
- Hardware and software version
- Week and year of manufacture
- LCD brightness
- Read error memory/fault codes.
The button status function can be used to determine the correct functioning of the switch-pack. Sticking buttons can be observed on the TestBook/T4 screen as well as the correct functioning of all the keys as they are pressed.
Fault codes
Fault codes are stored in the memory of the system ECUs and are accessed using TestBook/T4. The following table 'ECU fault codes' lists the faults that can be stored by the navigation computer memory.
ECU fault codes
Service Mode
To enter service mode on the high line system, select SET on the menu screen and hold the menu button for eight seconds. This will then display the 'service mode' menu screen.
- On-board monitor
- NAVIGATION / GRAPHIC ELEMENT
- Video module
- GPS
- Sensor check.
On-board Monitor
Selecting the 'On-board monitor' option displays the 'On-board monitor version' screen as follows.
- SW level
- HW level
- DIAG index
- Bus index
- Encoding index
- Supplier.
If version is selected the 'ON BOARD MONITOR VERSION' screen will be displayed as described above.
- Version
- Key function
- Brightness- the screen brightness can be adjusted by selecting this option.
Select the 'key function' menu by rotating the LH rotary control and depressing it. The 'ON-BOARD MONITOR KEY FUNCTION' screen will be displayed. This allows each key on the display unit to be checked for operation. The screen also shows the following information:
- Key, the screen will show FF if no keys are pressed or FEH if several keys are pressed. The KEY box will change to reflect the button that has been pressed
- OBM increm sensor- The 'OBM increm sensor' box changes its value as the RH rotary control is turned
- Radio increment sensor- The 'OBM increm sensor' box changes its value when the LH (audio) rotary control is turned.
Navigation / Graphic Element
Selecting the Navigation / graphic element displays the following options:
- SW level
- HW level
- DIAG index
- Bus index
- Encoding index
- Supplier.
Video Module
Selecting 'Video module' will give the Video module information as follows
- SW level
- HW level
- DIAG index
- Bus index
- Encoding index
- Supplier.
GPS
On selecting GPS the following will be displayed:
GPS version information will appear as
- Receiver version
- Receiver software date.
Selecting the functions box allows the selection of,
- GPS version
- GPS status
- GPS tracking info.
Selecting 'GPS status' will display the following information.
- Latitude displays the current vehicle Latitude
- Longitude - displays the current vehicle Longitude
- Altitude - displays the current vehicle altitude
- Date/time - displays the current date and time
- G-speed/heading - displays the current vehicle speed and heading
- Rec-stat/Pos-Src displays the current receiver status and position source
- COMMERR - this tells us that there is a communication error between the GPS receiver and the navigation computer
- SEARCH Denotes that the system is searching for satellites
- TRACK - Denotes that the system is tracking satellites but does not have enough information to determine a position. It also shows that the system is functioning correctly
- POS This shows that the system is functioning correctly and is able to fix the position of the vehicle
- PDOP (Position Dilation Of Precision), HDOP ( Height Dilation Of Precision) and VDOP (Velocity Dilation Of Precision). These values tells us about the precision of geometric position. One is the best value where as a value of ten would mean there is no GPS positioning possible.
Selecting 'GPS TRACKING INFO' displays the following information.
- Ch PRN SIN-Displays the satellite being tracked on each channel and their signal strength
- Visible satellites- Displays the number of visible satellites
- Almanac- Displays YES or NO to show whether or not the system is receiving Almanac data.
Sensor Check
This screen will display information to check that all the input sensors are functioning correctly.
- Wheel sensors - These are used to calculate the vehicle speed
- GPS satellites Displays the number of satellites visible to the system at that time
- GPS Status - Displays the number of satellites visible to the system and the GPS status There are four possibilities for the status and they are as follows
- GPS Error - Communication error between the GPS receiver and the navigation computer. This could be a system failure
- Satellite search The system is searching for satellites. This may indicate a system failure
- Satellite contact - The system is tracking a number of satellites but does not have enough information to determine a position
- Position known - As the name suggests the system is tracking a number of satellites and has determined the vehicle position
- Gyro - The navigation computer incorporates a gyro which determines any changes in vehicle direction. In this screen it can be seen moving as the vehicle changes direction
- Direction - This sensor determines whether the vehicle is travelling forwards or backwards and will display FWD or BWD.
Exiting service mode 5 achieved by pressing the menu button on the control panel which returns the system to the main TV/Navigation screen.