Server device, an in-vehicle terminal device, and program of communication-based car navigation system
First Claim
1. A server device for use in a communication-based car navigation system connected to an in-vehicle terminal device through a communication network, comprising:
- guidance route search means for finding guidance route data from a current position to a destination with reference to a map database based on data on the current position and the destination delivered from said in-vehicle terminal device;
map extraction means for extracting map data including navigable roads for a region near said guidance route from said map database;
return route search means for finding direction data to return to the original route from each of links in a road network comprised of the extracted navigable roads; and
means for delivering said direction data to return to the original route associated with said guidance route data and extracted map data to said in-vehicle terminal device.
1 Assignment
0 Petitions
Accused Products
Abstract
In a communication-based navigation system, even when a vehicle deviates from an original guidance route, an in-vehicle terminal device can locate a new guidance route and display the same without receiving another guidance route delivered from a server device. Immediately after searching for a guidance route which is displayed at the start of running, the server device finds data on the shortest route from each node to a destination (direction data to return to the original route) in accordance with a shortest path algorithm, and delivers this data to the in-vehicle terminal device together with delivery map data including the guidance route. When the vehicle deviates from the guidance route, the in-vehicle terminal device locates a new guidance route or a return route from the location at which the vehicle deviates based on the direction data to return to the original route, and displays the guidance route or return route.
48 Citations
10 Claims
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1. A server device for use in a communication-based car navigation system connected to an in-vehicle terminal device through a communication network, comprising:
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guidance route search means for finding guidance route data from a current position to a destination with reference to a map database based on data on the current position and the destination delivered from said in-vehicle terminal device;
map extraction means for extracting map data including navigable roads for a region near said guidance route from said map database;
return route search means for finding direction data to return to the original route from each of links in a road network comprised of the extracted navigable roads; and
means for delivering said direction data to return to the original route associated with said guidance route data and extracted map data to said in-vehicle terminal device. - View Dependent Claims (5, 7, 8, 10)
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2. A server device for use in a communication-based car navigation system connected to an in-vehicle terminal device through a communication network, comprising:
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guidance route search means for finding guidance route data from a current position to a destination with reference to a map database based on data on the current position and the destination delivered from said in-vehicle terminal device;
map extraction means for extracting map data including navigable roads for a region near said guidance route from said map database;
return route search means for finding direction data to return to the original route from each of links in a road network comprised of the extracted navigable roads;
means for converting said guidance route data and extracted map data to delivery map data;
flag addition means for converting said direction data to return to the original route to flag data appended to a link sequence data in said delivery map data, and adding said converted flag data to said delivery map data; and
means for delivering said delivery map data to said in-vehicle terminal device. - View Dependent Claims (6, 9)
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3. A program for a server device for use in a communication-based car navigation system connected to an in-vehicle terminal device through a communication network, said program causing a computer of said server device to function as:
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guidance route search means for finding guidance route data from a current position to a destination with reference to a map database based on data on the current position and the destination delivered from said in-vehicle terminal device;
map extraction means for extracting map data including navigable roads for a region near said guidance route from said map database;
return route search means for finding direction data to return to the original route from each of links in a road network comprised of the extracted navigable roads;
means for delivering said direction data to return to the original route associated with said guidance route data and extracted map data to said in-vehicle terminal device.
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4. A program for a server device for use in a communication-based car navigation system connected to an in-vehicle terminal device through a communication network, said program causing a computer of said server device to function as:
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guidance route search means for finding guidance route data from a current position to a destination with reference to a map database based on data on the current position and the destination delivered from said in-vehicle terminal device;
map extraction means for extracting map data including navigable roads for a region near said guidance route from said map database;
return route search means for finding direction data to return to the original route from each of links in a road network comprised of the extracted navigable roads;
means for converting said guidance route data and extracted map data to delivery map data;
flag addition means for converting said direction data to return to the original route to flag data appended to a link sequence data in said delivery map data, and adding said converted flag data to said delivery map data; and
means for delivering said delivery map data to said in-vehicle terminal device.
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Specification