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 delays and incidents.

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 gauge control module 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 HandsFreeLink control unit, rear controller and screen, and the audio system. The information passed on this bus is audio settings directed by the audio-navigation unit.

HDD Navigation System

The Pilot uses a HDD (hard disc 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 is provided by Grace note.
- Customers 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 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 with the update disc.
- Map software - This is commonly referred to as update navigation DVD that customers can order to update their map info, POI DB, and CDDB information. This also comes pre-loaded on the HDD, but the customer 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 customer had installed on their HDD.

If a customer wants to order an update, see Ordering an Update Navigation DVD.

The Grace note CDDB is updated quarterly.

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

Warning of extreme temperatures in the audio-navigation unit is displayed on the navigation screen as an error message.

USB Adapter

The USB module is built into the audio-navigation unit. Customers 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 is a functionality that provides three different view images of the rearview camera to the navigation display unit, and can be changed by user operation. The guiding lines are different according to the view mode difference. The rearview 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 confirm any objects approaching from right and left.
- Top Down View Mode
The display shows the view from the top angle of the vehicle, which helps the driver confirm the distance from any object behind.

When the vehicle is in R position, the rearview camera image automatically appears on the navigation display. You can change the display while the vehicle is in R position by pressing the interface dial.

ENTER:
The rearview 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 vehicle is in R position) 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 shift lever 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.

2. 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.

3. 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, 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

Navigation Function

The navigation system is composed of the audio-navigation unit, the PCM (vehicle speed pulse), the HandsFreeLink control unit (to send a POI phone number or place a call), the GPS antenna, the microphone, the voice control switch, the navigation display unit, the interface dial, the rearview camera, and the audio-navigation switch panel.

Function Diagram

GA-Net Bus Configuration

The GA-Net bus passes audio, navigation, rear entertainment, and HFL commands throughout the audio, navigation, and HFL 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 output shaft (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.

5. 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 accuracy 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 audio-navigation unit to adjust vehicle position and the clock in the audio-navigation switch panel display.

Radio Data System-Traffic Message Channel (RDS-TMC)

The Radio Data System-Traffic Message Channel (RDS-TMC) is a radio broadcast used for delivering traffic and travel information to the driver. The RDS-TMC data is typically coded using the 57 kHz±3 kHz subcarrier on FM broadcast.

The RDS-TMC system uses a decoder build into the audio-navigation unit to decode the traffic information data.

The traffic information is displayed with the navigation route guidance. The navigation system uses this information to help avoid traffic jams and traffic delays caused by accidents. (see the Navigation Manual for more information).

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 tuning is accomplished by indicating the vehicle position on the roads on the map. 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.

Dynamic 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. This is not selectable (button grayed out) for trips greater than 100 miles.
- Minimize Toll Roads-Calculate a route that avoids, or minimizes travel on toll roads. This is not selectable (button grayed out) for trips greater than 100 miles.
- 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 center speaker.

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:

HFL has the highest priority, followed by navigation, and finally the radio/CD-DVD player. The priority is passed by HFL to the audio-navigation unit by dedicated mute wires. 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, the XM receiver, the disc player, or other audio accessories.

When the navigation system sends out a voice route guidance command, the front speaker(s) sound is reduced, and the navigation voice is heard through in the front speaker(s).

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

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 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.

Control Interface

Navigation Display Unit

The display unit uses a liquid crystal display (LCD). The LCD is an 8-inch-diagonal, thin film transistor (TFT), strip type with 336,960 picture elements. The color film and fluorescent light are laid out on the back of the liquid crystal film.

TALK Button

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

NOTE: If the navigation volume and/or voice feedback is turned off, this feature is disabled.

BACK Button

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

PICK-UP Button

This button is used to answer incoming calls or to make outgoing calls. You can also go directly to the Cellular Phone screen by pressing this button.

HANG-UP Button

This button is used to end a call.

Navigation Switch Panel

- The navigation hard buttons and interface dial are used to input commands.
- The display mode button switches the display between Day mode, Night mode, and off.
NOTE: When you activate this button, the navigation auto dimming is turned off until you turn the ignition switch to LOCK (0).
- The audio button displays the audio system information.

HFL-Navigation Voice Control Switch

The navigation voice control switch is combined with the HFL switch. navigation TALK/BACK commands are sent to the audio-navigation unit via the HandsFreeLink control unit.

Microphone (HFL-Navigation-ANC)

Receives voice commands and transmits them to the audio-navigation unit or HandsFreeLink control unit. The microphone unit consist of two microphones. One microphone is combined with the front active noise cancellation microphone. The microphones detects the driver's voice and the passenger's voice separately.

Glossary

The following is a glossary of terms pertaining to the navigation system.

NOTE: All items may not apply to this vehicle. See the Navigation 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 DEST/ROUTE, MAP/GUIDE, and CANCEL, or by connecting the 2-PIN SCS service 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.

NOTE: Do not clear or change settings unless specified by either the troubleshooting procedures or by the factory.