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Home >> Infiniti Truck >> 2012 >> QX56 RWD V8-5.6L (VK56VD) >> Repair and Diagnosis >> Accessories and Optional Equipment >> Radio, Stereo, and Compact Disc >> Description and Operation >> Multi AV System >> System Description >> Part 1

Part 1



SYSTEM

MULTI AV SYSTEM : System Description

Multi AV system means that the following systems are integrated.






COMMUNICATION SIGNAL

- 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.
- AV control unit is connected by CAN communication, and it receives data signal from ECM and combination meter It computes and displays fuel economy information value with the obtained information. Transmitting/
receiving of data signal is performed by BCM. Also, it transmits the required signal of vehicle setting and receives the response signal.
- AV control unit is connected with front display unit and serial communication, and it transmits the required signal of display and display control and receives the response signal from front display unit.

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 BOSE 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 satellite and map data stored on HDD (Hard Disk Drive), and transmits the map image signal (RGB image, RGB
area, RGB image synchronizing) 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.
Map-matching





Map-matching repositions the vehicle on the road map when a new location is judged to be more accurate. This is done by comparing the current vehicle position (calculated by the normal position detection method) from the map data stored in the HDD (Hard Disk Drive).
There is a possibility that the vehicle position may not be corrected in the following case, and when vehicle is driven over a certain distance or time in which GPS information is hard to receive. Correct manually the current location mark on the screen.





- In map-matching, several alternative routes are prepared and prioritized in addition to the road judged as currently driving on.
Therefore, due to errors in the distance and/or direction, an incorrect road may be prioritized, and the current location mark may be repositioned to the incorrect road.
If two roads are running in parallel, they are of the same priority.
Therefore, the current location mark may appear on either of them alternately, depending on maneuvering of the steering wheel and configuration of the road, etc.





- Map-matching does not function correctly when road on which the vehicle is driving is new, etc. and not recorded in the map data.
Also, map-matching does not function correctly when road pattern stored in the map data and the actual road pattern are different due to repair, etc.
Therefore, the map-matching function judges other road as a currently driving road if the road is not in the map, and displays the current location mark on it. Later, the current location mark may be repositioned to the road if the correct road is detected.
- Effective range for comparing the vehicle position and travel direction calculated by the distance and direction with the road data is limited. Therefore, correction by map-matching is not possible when there is an excessive gap between current vehicle position and the position on the map.
GPS (Global Positioning System)





GPS (Global Positioning System) is developed for and is controlled by the US Department of Defense. The system utilizes GPS satellites (NAVSTAR), transmitting out radio waves while flying on an orbit around the earth at an altitude of approximately 21,000 km (13,049
mile).
The receiver calculates the travel position in three dimensions (latitude/longitude/altitude) according to the time lag of the radio waves that four or more GPS satellites transmit (three-dimensional positioning). The GPS receiver calculates the travel position in two dimensions (latitude/longitude) with the previous altitude data if the GPS
receiver receives only three radio waves (two-dimensional positioning). GPS position correction is not performed while stopping the vehicle.
Accuracy of the GPS will deteriorate under the following conditions:
- In two-dimensional positioning, GPS accuracy will deteriorate when altitude of the vehicle position changes.
- The position of GPS satellite affects GPS detection precision. The position detection may not be precisely performed.
- The position detection is not performed if GPS receiver does not receive radio waves from GPS satellites.
(Inside a tunnel, parking in a building, under an elevated highway etc.) GPS receiver may not receive radio waves from GPS satellites if any object is placed on the GPS antenna.
NOTE:
- The detection result has an error of approximately 10 m (32.81 ft) even with a high-precision three dimensional positioning.
- There may be cases when the accuracy is lowered and radio waves are stopped intentionally because the
GPS satellite signal is controlled by the US trace control center.

AUDIO FUNCTION

The audio system is equipped with the following functions. Each function is operated with multifunction switch, preset switch, touch panel, steering switch or audio recognition. Operation status of audio is indicated at display.
Description
- The audio function is adoption of the following system, and it is equipped with the following functions.





- 15 speakers models is adoption of BOSE� Centerpoint� 2 enables sound effects with a sense of realism even to playback sound of two-channel audio.
- The table below shows speakers mounted to each system.





Operating Signal
Audio system operation can be performed with multifunction switch, preset switch, steering switch, touch panel function or voice recognition function.
- Operating signal is transmitted to AV control unit with AV communication when it is operated by multifunction switch or preset switch. The disk ejection operating signal is performed by hardwire.
- Operating signal is transmitted to AV control unit with steering switch signal when it is operated by steering switch.
Screen Display
Switching of display is performed with serial communication between front display unit and AV control unit.
AM/FM Radio Mode
- AM/FM radio tuner is built into AV control unit.
- AM/FM radio wave is received by radio antenna, next it is amplified by antenna amp., and finally it is input to
AV control unit.
- FM radio wave is received by FM sub antenna, and it is transmitted to the AV control unit directly.
- Audio signal is input to BOSE amp. and BOSE amp. outputs to each speaker.
Satellite Radio Mode
- Satellite radio tuner is built into AV control unit.
- Sound signal (satellite radio) is received by satellite radio antenna and transmitted to AV control unit. AV
control unit outputs sound signal to BOSE amp. The signal is also outputted from BOSE amp. to each speaker.
CD Mode
- CD function is built into AV control unit.
- AV control unit outputs audio signal to BOSE amp., and BOSE amp. outputs to each speaker when CD is inserted to AV control unit.
Bluetooth(tm) Audio Mode
- Bluetooth(tm) audio function is built into AV control unit.
- Bluetooth(tm) audio can play music data in the portable audio by means of Bluetooth(tm) communications between the portable audio and the AV control unit.
- AV control unit outputs audio signal to BOSE amp., and BOSE amp. outputs to each speaker.
Music Box Mode
- Music CD data is stored on HDD that is built into AV control unit, and it can be played.
- AV control unit outputs music (sound signal) that is stored on HDD to BOSE amp., and BOSE amp. outputs to each speaker.
Speed Sensitive Volume
- Volume level of this system gone up and down automatically in proportion to the vehicle speed.
- The control level can be selected by the customer.
Driver's Audio Stage
- Driver's Audio Stage controls the speaker's output characteristic by BOSE amp. so that the driver's seat is to be the center of sounds.
- ON/OFF signals of Driver's Audio Stage are transmitted from AV control unit to BOSE amp. using mode change signal.
BOSE� Centerpoint� 2 (BOSE� Studio Surround� Sound System)
- BOSE � Centerpoint� 2 provides a surround-sound effect, based on a stereo sound source, such as CD or
MP-3.
- The BOSE amp. receives a BOSE� Centerpoint� 2 ON signal during a stereophonic sound playback and divides the sound among five channels to add a sense of simulated surround playback sound.

DVD PLAY FUNCTION

- DVD is played by inserting DVD into the AV control unit.
- DVD image signals are transmitted to the front display unit (except for Mexico), and DVD sound signals are transmitted to each speaker via BOSE amp.
- DVD image signals and sound signals are transmitted to the headrest display unit via the video distributor.
The headrest display unit transmits the sound signals to the headphone via infrared communication.

USB CONNECTION FUNCTION

- Connecting iPod� or USB memory allows the driver to play iPod� music files or USB memory-stored music files, video data, and image viewer data.
- Sound signals of music files stored in iPod� or USB memory are transmitted from the USB connector to the
AV control unit. The AV control unit transmits the sound signals to the BOSE amp. and video distributor.
- Sound signals transmitted from the BOSE amp. to each speaker, and sound signals transmitted from the video distributor to headphone via headrest display unit
- Video signals and image viewer file signals are transmitted from the USB connector to the AV control unit.
The data and files are displayed on the front display unit screen.
- Video signals are transmitted from the USB connector to the AV control unit. The data and files are displayed on the headrest display unit screen.
- iPod � is recharged when connected to USB connector.
- Only files that meet the following conditions will be played.





NOTE:
- iPod � is a trademark of Apple inc., registered in the U.S. and other countries.
- Image signals cannot be received from iPod�.
- Use the enclosed USB harness when connecting iPod� to USB connector.
- If a video-sound code combination is not satisfied, its video file may not be played.
- Signals cannot be transmitted to video distributor under the following conditions:
- Only sound signal or only image viewer data is stored in iPod�
- Only sound signal or only image viewer data is stored in USB memory

FRONT AUXILIARY INPUT FUNCTION

- Image and sound can be output from an external device by connecting a device with front auxiliary input jacks.
- AUX image signals are transmitted to each unit as follows:
- To the front display unit via AV control unit.
- To the headrest display unit via AV control unit and video distributor.
- AUX sound signals are transmitted to each unit as follows:
- To each speaker via AV control unit and BOSE amp.
- To the video distributor via AV control unit, and headphone sound signals are transmitted to infrared communication between headrest display unit and headphone.

MOBILE ENTERTAINMENT SYSTEM

- Image and sound (DVD, USB memory-stored video data and front auxiliary input) played by AV control unit can be enjoyed in rear seat using headrest display unit and headphone.
- Image and sound of external device connected to rear auxiliary input jacks for rear seat can be enjoyed in rear seat using headrest display unit and headphone. Also, image and sound from rear auxiliary input jacks can be selected and played individually on each side as well as on both sides.
- Headrest display unit has the self-diagnosis function. Testing and Inspection.
NOTE:
Image signal and sound signal from rear auxiliary input jacks is not transmitted to front display unit and each speaker.
Operating Signal
- The mobile entertainment system can be controlled by one of the rear seat remote controller.
- It receives the operation signal of the rear seat remote controller by the remote control receiver built into headrest display unit, and then transmits it to the AV control unit and the video distributor.
Headphone Sound
- Sound signal output from AV control unit or rear auxiliary input jacks are transmitted to headrest display unit via video distributor.
- Headphone sound signals are transmitted to infrared communication between headrest display unit and headphone.
Screen headrest display
- Image signal output from AV control unit or rear auxiliary input jacks are transmitted to headrest display unit via video distributor.
- Image switch signal is input from headrest display unit to AV control unit or from headrest display unit to video distributor, according to rear seat remote controller operation.
- When image switch signal is transmitted from headrest display unit to AV control unit via AV communication, image played by AV control unit (DVD, USB memory-stored video data, and front auxiliary input) switches.
- When image switch signal is input from headrest display unit to video distributor via hard wire, image output from AV control unit and image output from rear auxiliary input jacks switch.
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