❒ If you use chains on your wheels for winter
NAVI/AV | driving or put on the spare wheel, errors may | |
suddenly increase because of difference in | ||
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| wheel diameter. The system detects the fact | |
| that the tire diameter has changed, and auto- | |
| matically replaces the value for calculating | |
| distance. | |
| ❒ If the | |
| ating in Simple hybrid mode, the distance cal- | |
| culation value cannot be replaced | |
| automatically. |
Map matching
As mentioned, the GPS and dead reckoning sys- tems used by this Navigation System are suscep- tible to certain errors. Their calculations may, on occasion, place you in a location on the map where no road exists. In this situation, the processing system understands that vehicles travel only on roads, and can correct your posi-
Appendix | tion by adjusting it to a nearby road. This is called | ||
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| map matching. | ||
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With map matching
Without map matching
Handling Large Errors
Positioning errors are kept to a minimum by com- bining GPS, Dead Reckoning, and map match- ing. However, in some situations, these functions may not work properly, and the error may become bigger.
When the positioning by GPS is impossible
•If signals cannot be received from more than two GPS satellites, GPS positioning does not take place.
•In some driving conditions, signals from GPS satellites may not reach your vehicle. In this case, it is impossible for the system to use GPS positioning.
In tunnels or enclosed parking garages
Under elevated roads or similar
When driving among high buildings
When driving through a dense forest or tall trees
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