Navigation System Description - Overview
Basic Configuration
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 or more 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.
Audio-Navigation Unit
Refer to the Audio System Overview for the audio-navigation unit (display audio) and audio functions. The audio-navigation unit saves the navigation map data in its own memory.
Navigation Function
The basic navigation system is composed of the audio-navigation unit, vehicle signal (vehicle speed pulse, reverse signal), and the GPS antenna.

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 interprets voice commands. With control of all these items, the audio-navigation unit makes the navigation picture signal, then it sends the signal to the display.

Function Diagram
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, the acceleration sensor, and the travel distance signals from vehicle speed pulse (VSP) of the PCM and the BACK-LT (reverse) signal.
Map Matching Tuning
Map match tuning means that the vehicle's position is properly indicated on mapped roads. The map data transmitted from the SD card module is checked against the current vehicle position data and the vehicle's position is indicated on the nearest road. Map matching tuning cannot be done when the vehicle is on an unmapped road, or if the vehicle is far away from a mapped road.
GPS Tuning
GPS tuning improves the accuracy of the vehicle's actual position in relation to the GPS vehicle position. The audio-navigation unit compares its calculated vehicle position with the GPS position. If there is a large difference between the two positions, the GPS tuning adjusts the calculated vehicle position to the GPS position.
Distance Tuning
The audio-navigation unit compares the vehicles calculated distance using the VSP and the vehicle's actual position based on GPS data. If the values are different, the audio-navigation unit decreases or increases the tuning value depending if the vehicle's calculated position is always ahead or behind the GPS position.
Vehicle Speed Pulse
The vehicle speed pulse is sent by the PCM. The PCM receives a signal from the output shaft speed sensor, then processes the signal and transmits it to the speedometer and other systems.
Gyro Sensor
The gyro sensor (located in the audio-navigation unit) detects the direction change (angular speed).
Oscillation Gyro Principles
The gyro sensor is an oscillation gyro built into the audio-navigation unit. 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.

Gyro Sensor
When the vehicle turns left or right, the gyro sensor outputs the voltage. But the sensor outputs the offset voltage at the static status. The audio-navigation unit calculates the relative bearing of the vehicle from the offset voltage. Since the vehicle may generate the yaw rate even in state of stopping (when the vehicle is spun on a turn table), the audio-navigation unit inhibits incorrect calculation using the gyro sensor temperature information.

Auto Tuning
The sensitivity behavior of the gyro sensor has individual specificity, it is necessary to calculate a sensitivity correction coefficient for every unit. A sensitivity correction coefficient is automatically learned during the vehicle moving.

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.

Number of Satellites
Condition
Description
None
(Displayed in diag mode)
Faulty reception
The GPS cannot be utilized due to a faulty GPS receiver or antenna, or other fault or interference.
2 or less
Impossible to detect vehicle position
GPS function is normal. The satellite signals received by the GPS are too few to detect the vehicle position.
3
Vehicle position detectable in 2 dimensions
The longitude and latitude of the vehicle position can be detected (less precise than detection in three dimensions).
4 or more
Vehicle position detectable in 3 dimensions (elevation displayed)
The longitude, latitude and the altitude of the vehicle position can be detected (more precise than detection in two dimensions).
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 display and in the gauge module.
Audio Guidance
The audio-navigation unit transmits audio driving instructions before entering an intersection or passing a junction. The audio instructions come through the driver's door speaker.
Voice Control Function
This navigation system also has voice recognition that allows voice control of most of the navigation functions. The TALK and HANG-UP/BACK buttons on the steering wheel activate the voice control. The voice control also allows control of the audio and climate functions.

If the vehicle is equipped with climate control and the driver is using voice recognition, the audio-navigation unit sends the fan mute signal to the climate control unit via the B-CAN bus. The blower fan operating voltage may be reduced depending on the current fan speed.
HD Traffic(TM)
The HD Traffic(TM) is a broadcast for delivering traffic information to the driver. The HD Traffic(TM) data is supplied by the FM broadcast.

The HD Traffic(TM) uses a decoder in the audio-navigation unit to decode the traffic information data. It is integrated directly into a navigation system. The traffic information is displayed with the navigation route guidance. It is used to avoid traffic jams and accidents (see the Navigation Manual for more information).
Multi-View Rearview Camera
The multi-view rearview camera allows the driver to see what is behind the vehicle by displaying the image on the audio-navigation unit. There are three different selectable views. Refer to the Audio System Overview.
HondaLink Assist
HondaLink delivers remote services to the vehicle using the customer's compatible Bluetooth phone. Refer to the Audio System Overview.
HFL (Navigation Voice Control) Switch
TALK Button: Activates the voice control system in the audio-navigation unit to accept voice commands.
HANG-UP/BACK Button: Returns the display to the previous screen (similar function as the CANCEL button), or is used to end a call.
PICK-UP Button: This button is used to answer incoming calls or to make outgoing calls. You can also go directly to the Phone screen by pressing this button.
HFL Microphone
The system microphones change sensitivity based on operating mode. For navigation system voice commands, the microphones gives strong preference to the driver's voice. Refer to the HandsFreeLink System Overview.