Navigation System Description

Navigation System Description

Overview

The navigation system is a highly-sophisticated, hybrid locating system that uses satellites and a map database to show you where you are and to help guide you to a desired destination.

The navigation system receives signals from the global positioning system (GPS), a network of 24 satellites in orbit around the earth. By receiving signals from several of these satellites, the navigation system can determine the latitude, longitude, and elevation of the vehicle. In addition, signals from the system's yaw rate sensor and the PCM (vehicle speed pulse) enable the system to keep track of the vehicle's direction and speed of travel.

This hybrid system has advantages over a system that is either entirely self-contained or one that relies totally on the GPS. For example, the self-contained portion of the system can keep track of vehicle position even when satellite signals cannot be received. When the navigation system is on, the GPS can keep track of the vehicle position even when the vehicle is transported by ferry.

The navigation system applies all location, direction, and speed information to maps and calculates a route to the destination entered. As you drive to that destination, the system provides both visual and audio guidance.

The navigation system also uses dynamic route guidance to help avoid traffic delay and incidents. Clients need to subscribe to real-time traffic for this function to work.

This navigation system also has voice recognition that allows voice control of most of the navigation functions. The TALK and BACK buttons on the steering wheel activate the voice control. The voice control also allows control of the audio and climate functions.

The illumination signal (headlights ON) is used by the audio-navigation unit to automatically switch the display between Night and Day brightness modes. When the instrument panel brightness control is set to full brightness, the navigation system stays in the day mode, even with the headlights on.

The GA-NET II communication bus passes information back and forth between the navigation display, the audio-navigation unit, the RES/audio system, the HFL, and AcuraLink. The information passed on this bus is audio climate control settings directed by the audio-navigation unit.

The Comm. Bus connects the HFL, XM (HIP) (AcuraLink), and audio-navigation units. This bus supports these functions:

- The audio-navigation unit receives traffic, weather, and AcuraLink message information from the AcuraLink control unit.
- The audio-navigation unit sends a POI phone number (on the Calculate route to screen) to the HandsFreeLink control unit for dialing.
- If vehicle problems are detected, and the client's cellular contract includes data service, then the AcuraLink control unit (XM receiver) can send vehicle data to the HFL unit for transmitting back to the AcuraLink servers.
- The AcuraLink server can pass additional problem details back through the AcuraLink control unit, to the audio-navigation unit for display.

HDD Navigation System

The 2010-11 MDX uses a HDD (hard disk drive) instead of a navigation DVD. The HDD system improves route calculation and POI searching time, as well as these additional functions:

- Ripping music to the HDD with on-board CDDB (CD database) information provided by Gracenote.
- Clients can save their personal pictures to the HDD and use the images as wallpaper when they are not using the navigation system.
- See the Owner's manual or navigation system manual for more information.

There are two software programs that run on the audio-navigation system:

- Navigation system software - This software comes pre-loaded on the HDD and runs the navigation system. It can be updated when a client orders a navigation update disc, or as directed by any official Acura service information like a service bulletin.
- Map software - This is commonly referred to as update navigation DVD that clients can order to update their map info, POI DB, and CDDB information. This also comes pre-loaded on the HDD, but the client can choose to update it yearly.

When you order a reman HDD, the latest navigation system software is loaded on the HDD, along with the latest Map software that the client had installed on their HDD.

If a client wants to order an update, see ordering an update navigation DVD.

The Gracenote CDDB is updated quarterly. Clients can visit www.acura.com and download the latest update.

The HDD shuts down to protect itself from damage, if the audio-navigation unit internal temperature is 183 °F (84 °C) or higher.

Temperature warnings are displayed on the navigation screen as an error message.

USB Adapter

The USB module is built into the audio-navigation unit. Clients can load images (which can be used as wallpaper), music, and the CDDB. Not all USB devices and devices functions work with the USB adapter. Please see the Owner's manual for more information.

Multi-View Rear Camera System

Overview

The multi-view rear camera system three different view images of the rearview camera to the navigation display unit, and can be changed by user operation. The guiding lines also change according to the view selected. The camera is connected directly to the navigation display instead of the audio-navigation unit to improve the time for the rearview image to appear on the display.

- Normal View Mode
The display shows the basic view.
- Wide View Mode
The display shows wider visibility than the normal view, which helps the driver spot any objects to the right or left of the vehicle.
- Top Down View Mode
The display shows the view from the top angle of the vehicle, which helps the driver spot any objects directly behind the vehicle.

When the vehicle is in R, the rearview camera image automatically appears on the navigation display. You can change the display while the vehicle is in R by pressing the interface dial. You can also adjust the rearview image brightness, and turn the yellow guide lines on and off.

ENTER:
The camera image changes between the wide view, the normal view, and the top down view in this order.

CANCEL button:
Pressing and holding the CANCEL button for three seconds turns the guide lines on and off.

INTERFACE DIAL:
You can change the rearview camera image brightness by rotating the interface dial. The brightness adjustment is not affected by the screen brightness adjustment in Setup.

Basic Control

When the navigation display detects the BACK UP LIGHT signal (when the gear selector is in R) for at least 0.5 seconds, the navigation display turns on the rearview camera. The navigation display delays for the 0.5 seconds to prevent changing the screen image too frequently because of incorrect gear selection.

Changing Camera Views

1. When the rearview camera image is displayed, pressing the interface dial in (ENTER) sends a signal from the audio-navigation unit, to the navigation display unit using the GA-Net BUS to change the camera angle view.

1. The navigation display unit recognizes the signal, and sends a signal to the rearview camera using the CAMERA BIT0 and CAMERA BIT1 signal lines to change the rearview camera view.

2. The rearview camera takes the digital video using the input signal, then sends the rearview image to the navigation display unit using the NTSC lines. The rearview image appears on the navigation display unit.

View Mode Memorization

Any time the audio-navigation unit loses power (battery disconnected, audio-navigation unit disconnected, etc.) the rearview camera defaults to the normal angle view. The rearview camera will also default to this angle if you had the top down angle selected when you turned the ignition switch to LOCK (0). If you change the rearview camera to the wide angle view, the camera will remember this view when you turn the ignition switch to ON (II).

System Diagram

With AcuraLink

Without AcuraLink

Navigation Function

The navigation system is composed of the audio-navigation unit, the PCM (vehicle speed signal), the AcuraLink control unit (traffic and weather information), the HandsFreeLink control unit (to send a POI phone number or place a call) the GPS antenna, microphone, the voice control switch, navigation display unit and front climate control unit display.

GA-Net Bus Configuration

The GA-Net bus passes audio and navigation commands throughout the navigation and RES/audio components. These commands include navigation audio/XM selections by voice, and XM station and music title names. Because the entire bus is interconnected between components, an open or short in the GA-Net bus harness may cause any or all of these functions to become inoperative.

Vehicle Speed Pulse

The vehicle speed pulse is sent by the PCM. The PCM receives a signal from the countershaft speed sensor, then processes the signal and transmits it to the speedometer and other systems.

Yaw Rate Sensor

The yaw rate sensor (located in the audio-navigation unit) detects the direction change (angular speed) of the vehicle. The sensor is an oscillation gyro built into the audio-navigation unit.

Sensor Element Structure

The sensor element is shaped like a tuning fork, and it consists of the piezoelectric parts, the metal block, and the support pin. There are four piezoelectric parts: one to drive the oscillators, one to monitor and maintain the oscillation at a regular frequency, and two to detect angular velocity. The two oscillators, which have a 90-degree twist in the center, are connected at the bottom by the metal block and supported by the support pin. A detection piezoelectric part is attached to the top of each oscillator. The driving piezoelectric part is attached to the bottom of one oscillator, and the monitoring piezoelectric part is attached to the bottom of the other oscillator.

Oscillation Gyro Principles

The piezoelectric parts have electric/mechanical transfer characteristics. They bend vertically when voltage is applied to both sides of the parts, and voltage is generated between both sides of the piezoelectric parts when they are bent by an external force. The oscillation gyro functions by utilizing this characteristic of the piezoelectric parts and Coriolis force. (Coriolis force deflects moving objects as a result of the earth's rotation.) In the oscillation gyro, this force moves the sensor element when angular velocity is applied.

Operation

- The driving piezoelectric part oscillates the oscillator by repeatedly bending and returning when an AC voltage of 6 kHz is applied to the part. The monitoring-side oscillator resonates because it is connected to the driving-side oscillator by the metal block.

- The monitoring piezoelectric part bends in proportion to the oscillation and outputs voltage (the monitor signal). The navigation unit control circuit controls the drive signal to stabilize the monitor signal.

- When the vehicle is stopped, the detecting piezoelectric parts oscillate right and left with the oscillators, but no signal is output because the parts are not bent (no angular force).

- When the vehicle turns to the right, the sensor element moves in a circular motion with the right oscillator bending forward and the left oscillator bending rearward. The amount of forward/rearward bend varies according to the angular velocity of the vehicle.

1. The detecting piezoelectric parts output voltage (the yaw rate signal) according to the amount of bend. The amount of vehicle direction change is determined by measuring this voltage.

Global Positioning System (GPS)

The global positioning system (GPS) enables the navigation system to determine the current position of the vehicle by using the signals transmitted from the satellites in orbit around the earth. The satellites transmit the satellite identification signal, orbit information, transmission time signal, and other information. When the GPS receiver receives a signal from four or more satellites simultaneously, it calculates the current position of the vehicle based on the distance to each satellite and the satellite's position in its respective orbit.

Position detection Image with GPS satellite

Precision of GPS

The precision of the GPS varies according to the number of satellites from which signals are received and the view of the sky. The precision is indicated by the color of the GPS icon shown on the display.

GPS Antenna

The GPS antenna amplifies and transmits the signals received from the satellites to the GPS receiver.

GPS Receiver and Clock

The GPS receiver is built into the audio-navigation unit. It calculates the vehicle position by receiving the signal from the GPS antenna. The current time, vehicle position and signal reception condition is transmitted from the GPS receiver to the navigation control unit to adjust vehicle position.

Audio-Navigation Unit

The audio-navigation unit calculates the vehicle position and guides you to the destination. The unit performs map matching correction, GPS correction, and distance tuning. It also controls the menu functions and the HDD, and interprets voice commands. With control of all these items, the audio-navigation unit makes the navigation picture signal, then it transmits the signal to the navigation display unit.

Calculation of Vehicle Position

The audio-navigation unit calculates the vehicle position (the driving direction and the current position) by receiving the directional change signals from the yaw rate sensor and the travel distance signals from vehicle speed pulse (VSP) signal of the PCM.

Map Matching Tuning

The map matching occurs when you drive the vehicle along a mapped road until the road name appears of the bottom of the screen. The map data transmitted from the HDD is checked against the vehicle position data, and the vehicle position is indicated on the nearest road. Map matching tuning does not occur when the vehicle travels on a road not shown on the map, or when the vehicle position is far away from a road on the map.

GPS Tuning

The GPS tuning is accomplished by indicating the vehicle position as the GPS's vehicle position. The audio-navigation unit compares its calculated vehicle position data with the GPS vehicle position data. If there is large difference between the two, the indicated vehicle position is adjusted to the GPS vehicle position.

Distance Tuning

The distance tuning reduces the difference between the travel distance signal from the VSP and the distance data on the map. The audio-navigation unit compares its calculated vehicle position data with the GPS vehicle position data. The audio-navigation unit then decreases the tuning value when the vehicle position is always ahead of the GPS vehicle position, and it increases the tuning value when the vehicle position is always behind the GPS vehicle position.

Traffic Information

The Acura navigation system's real-time traffic feature helps you avoid traffic delays by providing up to the minute traffic information in many metropolitan areas across the contiguous USA. Color coded freeways appear on the navigation screen, displaying current traffic flow, and/or the locations of accidents and traffic conditions affected by construction and weather. Real-time traffic data services are offered on a subscription basis for a nominal fee following the 90-day free trial period.

Weather Information

The Acura navigation system's weather information option allows you to view the weather forecast, warning list, and warning map. The weather information is available in a subscription basis for a fee following the 90-day free trial period.

Route Guidance

The audio-navigation unit can calculate different routes to a selected destination. You have five options:

- Direct Route-Calculate a route that is the most direct.
- Easy Route-Calculate a route that minimizes the number of turns needed.
- Minimize Freeways-Calculate a route that avoids freeway travel. If that is not possible, keep the amount of freeway travel to a minimum.
- Minimize Toll Roads-Calculate a route that avoids or minimizes travel on toll roads.
- Maximize Freeways-Calculate a route that uses freeways as much as possible.

Audio Guidance

The audio-navigation unit transmits audio driving instructions before entering an intersection or passing a junction. The audio instructions come through the stereo amplifier to the front speaker.

NOTE: The front speakers are muted whenever the navigation system is giving guidance commands, and all of the speakers are muted when the voice control system is being used.

Solar Angle

The climate control unit uses the sun's angle, along with the sunlight sensor, to control the driver/passenger A/C air flow.

Off Road Tracking (bread-crumbs)

Off road tracking dots that can be followed on the map to retrace your route back to a mapped (digitized) road.

Clock and Time Zone

The clock set up allows you to set daylight savings time, auto time zone and time adjustment.

Muting Signal Logic

The audio muting logic is orchestrated by the audio-navigation unit. The audio-navigation unit determines what audio source has priority to use the speakers.

The priority of the audio sources is as follows:

HandsFreeLink has the highest priority, followed by, AcuraLink, navigation, and finally the audio system (radio/CD-DVD/USB/AUX inputs). The priority is passed by HandsFreeLink and AcuraLink to the audio-navigation unit by B-CAN. The navigation mute signal is passed to the stereo amplifier.

The audio-navigation unit temporarily disables the voice control buttons, but allows guidance to be heard. In addition, the audio-navigation unit suppresses the output from the audio system, XM receiver, the disc player, or other audio accessories.

When the navigation system sends out a voice route guidance command, the door speaker sound output is reduced, and the navigation voice is heard in the center speaker.

When the navigation voice control system is in use, all of the speakers are muted, and the navigation voice prompts are heard from the center speaker.

Control Interface

Navigation Display Unit

The display unit uses a liquid crystal display (LCD). The LCD is a 8-inch-diagonal, thin film transistor (TFT). The color film and fluorescent light are laid out on the back of the liquid crystal film.

Microphone (HFL-navigation)

Receives voice commands and transmits them to the audio-navigation unit or HandsFreeLink unit for interpretation.
Both system share the same microphone.

TALK Button

Activates the voice control system in the audio-navigation unit to accept voice commands.

BACK Button

Returns the display to the previous screen (similar function as the CANCEL button).

Glossary

The following is a glossary of terms pertaining to the Voice Recognition Navigation System.

NOTE: All items may not apply to this vehicle. See the navigation system manual for more information.

Diagnostic System Diagram

This diagram below shows all of the navigation diagnostic features available for system troubleshooting. The diagram starts at the center, and works outward in layers.

Access to the diagnostic features begins by starting the vehicle. This is necessary so the system can check the other systems connected by various busses. After starting the vehicle you can enter the diagnostic mode either by pressing and holding MENU, MAP/GUIDE, and CANCEL, or by connecting the 2-PIN SCS connector.

The main menu screen allows 2 checking modes - one automatic, and one manual:

- The automatic diagnostic check starts when you select SELF DIAGNOSTIC MODE. The system runs for several seconds, and reports any issues with Red icons. Rotate the interface dial and select the icon you wish obtain the problem details.
- The manual diagnostic check is selected from the main menu by selecting DETAIL INFORMATION AND SETTING. The traditional diagnostic menu is displayed. This allows you to obtain additional details as instructed in the troubleshooting procedures.

Navigation Unit Connectors

NOTE: Refer to the audio section for audio-navigation unit connector D, E, H, and K inputs and outputs.

With rear entertainment