Design
Design
Control module
A DVD player is integrated in the multimedia module (MMM). The DVD player is used for navigation. The control module has various user functions such as:
- the start menu
- navigation
- system settings.
The start menu displays all the functions available to the user on the screen.
The navigation function in the multimedia module (MMM) calculates the position of the car using the signals from the GPS antenna. The GPS antenna is integrated in the antenna module (ATM).
The multimedia module (MMM) also has a built-in three dimensional piezo-electrical gyro. This supplies information about the movements of the car, such as any turns taken.
Information used from other nodes for navigation:
- the wheel rotation counter from the brake control module (BCM)
- back-up gear position from the transmission control module (TCM) and central electronic module (CEM)
- speed signal from the central electronic module (CEM).
Information from these control modules is transmitted to the infotainment control module (ICM) which then sends the information onwards to the multimedia module (MMM).
The map displayed on the screen indicates the position of the car. This position is adjusted using information from:
- the wheel rotation counter
- the speed signal
- the gyro in the multimedia module (MMM)
- the back-up gear position
- the GPS antenna
- the map matching function.
Information from the gyro and wheel rotation counter can be used for dead reckoning (i.e. to calculate the position). This happens for example when communication with the GPS satellites is lost such as when traveling through a tunnel.
The multimedia module (MMM) receives traffic information messages (TMC) from the antenna module (ATM) via the MOST network. This information is displayed on the directly connected display screen. The traffic message channel (TMC) is a standardized code system for traffic messages. It provides information about road works, heavy traffic etc. The Japanese equivalent of TMC is called FM multiplex. This system is not available in the USA.
The navigation function also includes voice guiding which instructs the driving how to reach the set destination.
The user can configure certain functions in the system settings. These functions are:
- date and time
- user settings, such as password.
The following functions are displayed on the directly connected display screen:
- navigation.
The control module transmits all the signals required to control the display screen.
The multimedia module (MMM) uses the Windows CE operating system.
Display screen
Functions such as Mobile office, system settings and navigation are presented on a 6.5" display screen in the center of the dashboard. The display screen is directly connected to the multimedia module (MMM). The control module transmits all the signals required to control the display screen.
If there is an internal fault in the screen or faults in communication with the control module, the quality of the display on the screen will deteriorate or the screen will stop working completely. A simple way to detect a fault in the screen, or communication problems between the screen and the control module, is to check the appearance of the image on screen.
The menu system on the display screen can be controlled either using the navigation buttons on the reverse of the steering wheel or using the screen remote control. The infra-red receiver for the remote control is on the infotainment control module (ICM).