Navigation system
First Claim
1. A navigation system comprising:
- a road map data storage for storing map data including road attribute data;
a route calculation unit for calculating a route from a current position to a destination by using the map data stored in the road map data storage unit, wherein the route includes a road to be followed from the current position;
a route guidance unit for performing a route guidance to the destination in accordance with the route calculated by the route calculation unit; and
a change unit for changing a distance of the road to be followed included in the route according to a road attribute of the road to be followed, wherein the road attribute is included in the road attribute data stored in the road map data storage unit,wherein, when the route calculation unit sets a branch point for branching to another road from the road to be followed, the branch point is set after the distance is exceeded.
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Accused Products
Abstract
When a vehicle performs route calculation at a current position, the number of lanes at the current position is found. A predetermined correspondence between the numbers of lanes and straight prioritized distances is used to find a straight prioritized distance at the current position corresponding to the number of lanes. A route to a destination from the current position is calculated so as to include, in the route, a road to be followed for the straight prioritized distance from the current position. When there are many lanes, the straight prioritized distance is set to be long. Accordingly, it is possible to avoid calculating a route that causes a guide to sudden right or left turn. When there are a few lanes, the straight prioritized distance is set to be short. Accordingly, it is possible to avoid calculating a roundabout route to the destination.
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Citations
19 Claims
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1. A navigation system comprising:
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a road map data storage for storing map data including road attribute data; a route calculation unit for calculating a route from a current position to a destination by using the map data stored in the road map data storage unit, wherein the route includes a road to be followed from the current position; a route guidance unit for performing a route guidance to the destination in accordance with the route calculated by the route calculation unit; and a change unit for changing a distance of the road to be followed included in the route according to a road attribute of the road to be followed, wherein the road attribute is included in the road attribute data stored in the road map data storage unit, wherein, when the route calculation unit sets a branch point for branching to another road from the road to be followed, the branch point is set after the distance is exceeded. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification