MULTI AV SYSTEM : System Description

Multi AV system means that the following systems are integrated.

FUNCTION NAME
Navigation system function
Audio function
DVD play function
Mobile entertainment system
Bluetooth™ hands-free phone function
Auxiliary input function
USB connection function
Voice recognition function
Touch panel function
Rear view monitor function
Vehicle information function
Auto Light adjustment system

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 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.

CAN COMMUNICATION

• 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.
• The AV control unit, which has the vehicle setting function, transmits and receives data on vehicle setting condition via CAN communication with the BCM.
• AV control unit receives steering angle signal from steering angle sensor via CAN communication and performs control of predictive course line in rear view monitor image.

TYPE OF VOICE SIGNAL

Reception Voice Signal

• Hands-free phone reception voice is output from the cellular phone through the AV control unit to the front speaker via Bluetooth™ communication.
• If the hands-free phone is used while the audio is ON and/or the voice guidance is being output, these sounds are muted and only the reception voice is output.

Speech Sound Signal

Hands-free phone speech sound is transmitted from the microphone via the AV control unit and Bluetooth™ communication to the cellular phone.

Guide Sound Signal

• Voice signals output during the route guidance of the navigation system are output from the AV control unit to the front speaker.
• If the voice guidance is output with the audio ON, audio output of the front speaker is turned down 10 dB and then voice guidance is output.
• Adjusting the volume while the voice guidance is being output can change the volume of the guidance.

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.

  Fig 2: Identifying Distance Traveled From Previous To Current Position

  Courtesy of NISSAN MOTOR CO., U.S.A.
  DIFFERENCE BETWEEN GYROSCOPE AND GPS ANTENNA
  
  

  Type	Advantage	Disadvantage
  Gyroscope (angular velocity sensor)	The turning angle is precisely detected.	Errors are accumulated when driving a long distance without stopping.
  GPS antenna (GPS information)	The travel direction (North/South/East/West) is detected.	The travel direction is not precisely detected when driving slowly.

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.

  Fig 4: Display Vehicle Route

  Courtesy of NISSAN MOTOR CO., U.S.A.
• 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.
  Fig 5: Display Vehicle Route (Newly Contructed Road)

  Courtesy of NISSAN MOTOR CO., U.S.A.

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.

AUDIO FUNCTION

Description

• BOSE sound system (special digital amp. and 12 speakers) is adopted.
• The adoption of the music box function enables the recording of music data to HDD.
• The MP3/WMA/AAC playback function enables music to play for a long time: the user need not change the CD during a long trip. The text display function is also adopted so that the title name and artist name of the ID3 tag/WMA/AAC tag can be displayed.
• The audio system is equipped with the following functions.
  AUDIO SYSTEM FUNCTION CHART
  
  

  FUNCTION
  AM/FM radio
  Satellite radio
  CD
  Bluetooth™ audio
  Music Box (Hard Disk Drive)
  Speed sensitive volume

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 eject signal is transmitted to AV control unit by hardwire, when disk eject switch is operated.
• Operating signal is transmitted to AV control unit with steering switch signal when it is operated by steering switch.
• Operation status of audio is indicated at front display.

AM/FM Radio Function

• 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 woofer and each speaker.

Satellite Radio Function

• Satellite radio tuner is built into AV control unit.
• Sound signal and data signal (satellite radio) are received by satellite radio antenna. There are input to AV control unit. AV control unit outputs sound signal to woofer and each speaker via BOSE amp. and data signal to front display unit.

CD Function

• CD function is built into AV control unit.
• AV control unit outputs sound signal to BOSE amp., and BOSE amp. outputs to woofer and each speaker when CD is inserted to AV control unit.
• For further information about CD function specifications, refer to "AV CONTROL UNIT ".

Bluetooth™ Audio Function

• Bluetooth™ audio function is adopted to play music data in the portable audio in wireless communication.
• Five units of Bluetooth™ communication devices including audio devices and cellular phones can be registered to the AV control unit.
• When the Bluetooth™ audio is connected to the portable audio through Bluetooth™, it can play the music data in the portable audio.
• For further information about Bluetooth™ compliant profile, refer to "AV CONTROL UNIT ".

Music Box Function

• 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 woofer and each speaker.
• For further information about music box function specifications, refer to "AV CONTROL UNIT ".

Speed Sensitive Volume Function

• The AV control unit receives the vehicle speed signal from the combination meter via CAN communication and changes the sound volume in conjunction with the vehicle speed.
• The control level can be selected by the customer.

DVD PLAY FUNCTION

• DVD is played by inserting DVD into the AV control unit.
• DVD image signals are transmitted to the front display unit, and DVD sound signals are transmitted to woofer and each speaker via BOSE amp.
• DVD image signals are transmitted to rear display unit via video distributor, and DVD sound signals are transmitted to rear display unit. The rear display unit transmits the sound signals to the headphone via infrared communication.
• For further information about DVD function specifications, refer to "AV CONTROL UNIT ".

MOBILE ENTERTAINMENT SYSTEM

Image and sound (DVD, USB memory-stored video data, and auxiliary input) played by AV control unit can be enjoyed in rear seat using rear display unit and headphone.

Operating Signal

• The mobile entertainment system can be controlled by one of the remote controller.
• It receives the operation signal of the remote controller by the remote control receiver built into rear display unit, and then transmits it to the AV control unit.

Headphone Sound

Headphone sound signals are transmitted to infrared communication between rear display unit and headphone.

Screen rear display

• Image signal output from AV control unit is transmitted to the rear display unit.
• The rear display unit receives the composite image signal (DVD, USB memory-stored video data, and auxiliary input) from the AV control unit.
• The rear display unit switches composite images through the communications with the AV control unit via AV communication.

BLUETOOTH™ HANDS-FREE PHONE FUNCTION

• When the cellular phone is connected to the AV control unit in Bluetooth™ communication, hands-free phone communication can be performed.
• Simply operating the steering switch without releasing hands from the steering wheel allows the driver to make a phone call or receive a phone call.
• When a Bluetooth™ communication compliant phone is registered to the AV control unit, hands-free phone communication can be performed. Five units of Bluetooth™ communication devices including audio devices and cellular phones can be registered to the AV control unit.
• The content of the memory (telephone book) of the cellular phone can be recorded in the AV control unit.
• For further information about Bluetooth™ compliant profile, refer to "AV CONTROL UNIT ".

When A Call Is Originated

Spoken voice sound output from the microphone (microphone signal) is input to AV control unit. AV control unit outputs to cellular phone with Bluetooth™ communication as a TEL voice signal. Voice sound is then heard at the other party.

When Receiving A Call

Voice sound is input to own cellular phone from the other party. TEL voice signal is output to door speaker, and the signal is input to BOSE amp. via AV control unit by establishing Bluetooth™ communication from cellular phone.

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 front and rear display unit via AV control unit
• AUX sound signals are transmitted to each unit as follows:

• To each speaker via AV control unit and BOSE amp.
• To the rear display unit via AV control unit, and headphone sound signals are transmitted to infrared communication between rear display unit and headphone.

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 woofer and each speaker, and sound signals transmitted to headphone via rear 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 rear display unit screen.
• iPod® is recharged when connected to USB connector.
• Compliant USB memory and data recorded are limited.
  USB MEMORY SPECIFICATIONS
  
  

  USB memory	USB2.0
  File system	FAT16
  	FAT32

• Only files that meet the following conditions will be played.
  FILES REFERENCE CHART
  
  

  	Music file	Video file	Image viewer file
  File format	"MP3", "WMA", "AAC", "M4A"	"DivX", "MPEG4 (ASF)"	"JPEG"
  File extension	".mp3", ".wma", ".aac", ".m4a"	".divx", ".afs", ".avi"	".jpg", ".jpeg"
  Maximum file size	2 GB	2 GB	2 MB

VOICE RECOGNITION FUNCTION

• By speaking a command, operations of navigation and hands-free phone can be performed.
• To perform the voice control, press the switch of the steering switch. The system changes to the speech reception status. When a command is spoken, the speech recognition result is displayed, and the operation is executed.
• The voice control cannot be performed under the conditions listed below.

• When the hand-free phone is used
• When the vehicle is moving backwards

Major Functions

With this function, the list of commands used for telephone, and navigation operation can be checked.

TOUCH PANEL SYSTEM

Each operation of multi AV system can be performed by directly touching a front display.

REAR VIEW MONITOR FUNCTION

Operation Description

• When the selector lever is shifted to the reverse position, the rear view monitor image is displayed.
• When the selector lever is shifted to any position other than the reverse position, the original image (the image displayed before the rear view monitor image) is displayed.

Camera Image Operation Principle

• The AV control unit that receives the reverse signal input supplies power to the rear view camera and gives input of image signal.
• The AV control unit outputs the rear view camera image to the front display when the reverse signal is inputted.
• The AV control unit generates the warning message, side distance guiding lines and the predictive course lines on the image from the rear view camera, and transmits the rear view camera image signal to the front display unit.

Side Distance Guide Lines and Predictive Course Lines Display Function at Rear View Monitor Display

• The side distance guide lines and the predictive course line that indicate the vehicle route according to the steering angle are displayed at the rear view monitor display to allow the driver to more easily judge distances between the vehicle and objects and help the driver back into a parking space.
• The AV control unit receives the steering angle signal from the steering angle sensor via CAN communication and draws a predictive course line according to the steering angle signal.
• When the predictive course line are displayed, the side distance guide lines are displayed translucently.
• The predictive course line are not displayed when the steering is in the neutral position.
• The predictive course line can be displayed/not displayed by selecting "Settings" - "Others" - "Camera" - "Predictive Course Lines"
  Fig 7: Display Side Distance Guide Lines And Predictive Course Lines Display Function

  Courtesy of NISSAN MOTOR CO., U.S.A.

Precautions for Side Distance Guide Lines and predictive course line Display on the Rear View Monitor Display Side distance guide lines and predictive course line on the display may be different from actual lines depending on vehicle conditions and road conditions.

Precautions for road conditions

• Since guide lines and predictive course line are drawn based on the road, a different distance may be displayed if a protruding block is present nearby.
  Fig 8: Precautions For Road Conditions

  Courtesy of NISSAN MOTOR CO., U.S.A.

Precautions for block

• Since guide lines and predictive course line are drawn based on the road, a different distance may be displayed if a protruding block is present nearby.
  Fig 9: Precautions For Block

  Courtesy of NISSAN MOTOR CO., U.S.A.

VEHICLE INFORMATION FUNCTION

• Status of audio, climate control system, fuel economy, maintenance and navigation are displayed.
• AV control unit displays the fuel consumption status while receiving data signal through CAN communication from ECM and combination meter.

Vehicle Setting Function

The AV control unit transmits and receives data signals via CAN communication with the BCM, allowing the following vehicle settings.

• To turn on the automatic interior room lamp (ON/OFF) when the door is unlocked
• To adjust the auto light sensitivity (+/-)
• To operate the intermittent wiper linked with the vehicle speed (ON/OFF)
• Vehicle setting initialization

AUTO LIGHT ADJUSTMENT SYSTEM

When the light switch is in the 1st or 2nd position, the dimming of the display is judged according to a dimming signal transmitted from BCM to the AV control unit. Display illuminance is independent of vehicle exterior illuminance detected by the auto light detecting sensor even when the light switch is in 1st or 2nd position.