Honda ACCORD HYBRID 2005 Service Manual page 2054

Navigation System
S y s t e m D e s c r i p t i o n ( c o n t ' d )
Navigation Unit
The navigation unit calculates the vehicle position and guides you to the destination. The unit performs map matching
correction, GPS correction, and distance t u n i n g . It also controls the menu functions and the DVD-ROM drive, and
interprets voice c o m m a n d s . W i t h control of all these items, the navigation unit makes the navigation picture signal,
then it transmits the signal to the display unit and audio driving instructions to the audio unit.
Calculation of Vehicle Position
The navigation unit calculates the vehicle position (the driving direction and the current position) by receiving the
directional change signals f r o m the y a w rate sensor and the travel distance signals f r o m the PCMs vehicle speed pulse
(VSP) signal.
Map Matching Tuning
The map matching tuning is accomplished by indicating the vehicle position on the roads on the map. The map data
transmitted f r o m the DVD-ROM is checked against the vehicle position data, and the vehicle position is indicated on
the nearest road. Map matching t u n i n g does not occur w h e n the vehicle travels on a road not s h o w n on the map, or
w h e n the vehicle position is far away f r o m a road on the map.
G P S Tuning
The GPS tuning is accomplished by indicating the vehicle position as the GPS's vehicle position. The navigation unit
compares its calculated vehicle position data w i t h the GPS vehicle position data. If there is large difference between
the t w o , the indicated vehicle position is adjusted to the GPS vehicle position.
Distance Tuning
The distance tuning reduces the difference between the travel distance signal f r o m the VSP and the distance data on
the map. The navigation unit compares its calculated vehicle position data w i t h the GPS vehicle position data. The
navigation unit then decreases the t u n i n g value w h e n the vehicle position is always ahead of the GPS vehicle position,
and it increases the t u n i n g value w h e n the vehicle position is always behind the GPS vehicle position.
Route Guidance
The 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 — Calcute a route that minimizes the number of turns needed.
• Minimize F r e e w a y s — Calculate a route that avoids f r e e w a y travel. If that is not possible, keep the a m o u n t of
freeway travel to a m i n i m u m .
• 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 navigation unit transmits audio d r i v i n g instructions before entering an intersection or passing a j u n c t i o n .
The audio instructions come t h r o u g h the audio unit to the f r o n t speakers.
NOTE: The front speakers are muted w h e n e v e r the navigation system is giving guidance c o m m a n d s , and all of the
speakers w h e n the voice control system is being used.
DVD-ROM
The m a p data (including all scale rates) is stored in the DVD-ROM. The map data includes:
• Road distances, road w i d t h s , speed limits, traffic regulations, passing time at junction, distances to junctions, and
the driving instructions for audio guidance.
• Latitude and longitude GPS.
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