Nissan GT-R. Manual - part 4
AV
MULTI AV SYSTEM
AV-11
< SYSTEM DESCRIPTION >
[BASE AUDIO WITH NAVIGATION]
C
D
E
F
G
H
I
J
K
L
M
B
A
O
P
• AV control unit function by transmitting/receiving data one by one with each unit (slave unit) that configures
them completely as a master unit by connecting between units that configure MULTI AV system with two AV
communication lines (H, L).
• Two AV communication lines (H, L) adopt a twisted pair line that is resistant to noise.
• The AV control unit is connected with CAN communication line and receives data signals from the ECM,
combination meter, TCM, AWD control unit, A/C auto amp., ABS actuator and electric unit (control unit),
steering angle sensor and low tire pressure warning control unit. Using the obtained information, it computes
values for the display items relating to the fuel consumption information, multifunction meter, and tire pres-
sure information and displays them.
• AV control unit is connected with display and serial communication, and it transmits the required signal of
display and display control and receives the response signal from display.
• The AV control unit, which has the vehicle setting function, transmits and receives data on vehicle setting
condition via CAN communication with the BCM.
NAVIGATION SYSTEM FUNCTION
Description
• The AV control unit controls navigation function while GPS tuner has built-in map data, GYRO (angle speed
sensor), on the HDD (Hard Disk Drive).
• The AV control unit inputs operation signal with communication signal, through display (touch panel) and
multifunction switch and steering switch.
• Guide sound is output to front speaker through audio amp. from AV control unit when operating navigation
system.
• A vehicle position is calculated with the GYRO (angle speed sensor), vehicle sensor, signal from GPS satel-
lite and map data stored on HDD (Hard Disk Drive), and transmits the map image signal (RGB digital image
signal) to the display.
Position Detection Principle
The navigation system periodically calculates the current vehicle
position according to the following three types of signals.
• Travel distance of the vehicle as determined by the vehicle speed
sensor
• Vehicle turning angle determined by the gyroscope (angular speed
sensor)
• The travel direction of the vehicle determined by the GPS antenna
(GPS information)
The current position of the vehicle is then identified by comparing the
calculated vehicle position with map data, which is stored in the HDD
(Hard Disk Drive) (map-matching), and indicated on the screen with
a current location mark. More accurate data is used by comparing
position detection results from GPS to the map-matching.
The current position is calculated by detecting the travel distance
from the previous calculation point, and its direction change.
• Travel distance
The travel distance is generated from the vehicle speed sensor
input signal. The automatic distance correction function is adopted
for preventing a miss-detection of the travel distance because of
tire wear etc.
• Travel direction
The gyroscope (angular velocity sensor) and GPS antenna (GPS
information) generate the change of the travel direction. Both have
advantages and disadvantages as per the following descriptions.
Input signals are prioritized in each situation. However, this order of priority may change in accordance with
more detailed travel conditions so that the travel direction is detected more accurately.
JSNIA0177GB
SEL684V
Type
Advantage
Disadvantage
Gyroscope (angular velocity
sensor)
The turning angle is precisely detected.
Errors are accumulated when driving a long dis-
tance without stopping.
GPS antenna (GPS informa-
tion)
The travel direction (North/South/East/West) is
detected.
The travel direction is not precisely detected when
driving slowly.