Abridged map generating apparatus, on-vehicle information terminal, abridged map distribution system and abridged map generating method

• US 20060085122A1
• Filed: 10/17/2005
• Published: 04/20/2006
• Est. Priority Date: 10/18/2004
• Status: Active Grant

• Current Assignee: Clarion Co., Ltd. (Faurecia SA)
• Original Assignee: Xanavi Informatics Corporation (Hitachi, Ltd.)
• Inventors: Sumizawa, Akio, Morita, Manabu, Asahara, Akinori, Maruyama, Kishiko, Hiroike, Atsushi
• Granted Patent: US 7,493,212 B2
• Time in Patent Office: Days
• US Class Current: 701/208
• CPC Class Codes: G01C 21/367 Details, e.g. road map scale, orientation, zooming, illumination, level of detail, scrolling of road map or positioning of current position marker

Abstract

This abridged map generating apparatus includes an abridged map generation unit that generates an abridged map in which a shape of a road is simplified based upon road map data, wherein the road map data specifies the shapes of the road by shapes of links set for each predetermined road section, and the abridged map generation unit generates the abridged map by simplifying a shapes of a link or link series with fixed positions of both end points of the link or link series made by lining up a plurality of the links.

Claims

1. An abridged map generating apparatus, comprising:

an abridged map generation unit that generates an abridged map in which a shape of a road is simplified based upon road map data, wherein;

the road map data specifies the shape of the road by shapes of links set for each predetermined road section; and

the abridged map generation unit generates the abridged map by simplifying a shape of a link or link series with fixed positions of both end points of the link or link series made by lining up a plurality of the links.

2. An abridged map generating apparatus according to claim 1, wherein:

when the abridged map generation unit simplifies the shape of the link or link series, any point set in advance upon the link is selected as a preserved point and a position of the preserved point and the positions of both the end points are fixed respectively.

3. An abridged map generating apparatus according to claim 2, wherein:

the abridged map generation unit selects a point as the preserved point which is furthest from a first line segment which connects between both the end points among points set in advance upon the link.

4. An abridged map generating apparatus according to claim 1, further comprising:

a point selection unit that selects some point set in advance upon the link;

a line segment setting unit that sets a plurality of second line segments which connect between the point selected by the point selection unit and each of both the end points in order;

a direction revision unit that revises directions of each of the second line segments set by the line segment setting unit, so that each angle which is formed between each of the second line segments and a predetermined direction set in advance becomes an integer multiple of an unit angle set in advance;

an intersection point detection unit that obtains a point of intersection on which respective prolonged line segments obtained by prolonging the second line segments of which the direction has been revised by the direction revision unit are intersected each other; and

a length revision unit that revises a length of each of the second line segments, so as to connect together the point of intersection obtained by the intersection point detection unit and one of the end points or one of the points selected by the point selection unit; and

wherein;

the abridged map generation unit generates the abridged map by simplifying the shape of the link or link series, by using each of the second line segments of which the length are revised by the length revision unit.

5. An abridged map generating apparatus according to claim 4, wherein:

the point selection unit selects the point which is furthest from a first line segment which connects between both the end points among points set in advance upon the link.

6. An abridged map generating apparatus according to claim 5, wherein:

the point selection unit further selects points which are furthest from third line segments which connect between both the end points and the selected point respectively among points set in advance upon the link.

7. An abridged map generating apparatus according to claim 2, further comprising:

.

a point selection unit that selects some point set in advance upon the link;

a line segment setting unit that sets a plurality of second line segments which connect between the point selected by the point selection unit and each of both the end points in order;

a direction revision unit that revises directions of each of the second line segments set by the line segment setting unit, so that each angle which is formed between each of the second line segments and a predetermined direction set in advance becomes an integer multiple of an unit angle set in advance;

an intersection point detection unit that obtains a point of intersection on which respective prolonged line segments obtained by prolonging the second line segments of which the direction has been revised by the direction revision unit are intersected each other; and

a length revision unit that revises a length of each of the second line segments, so as to connect together the point of intersection obtained by the intersection point detection unit and one of the end points or one of the points selected by the point selection unit; and

wherein;

the abridged map generation unit generates the abridged map by simplifying the shape of the link or link series, by using each of the second line segments of which the length are revised by the length revision unit.

8. An abridged map generating apparatus according to claim 7, wherein:

the point selection unit selects the point which is furthest from a first line segment which connects between both the end points among points set in advance upon the link.

9. An abridged map generating apparatus according to claim 8, wherein:

the point selection unit further selects points which are furthest from third line segments which connect between both the end points and the selected point respectively among points set in advance upon the link.

10. An abridged map generating apparatus according to claim 3, further comprising:

a point selection unit that selects some point set in advance upon the link;

a line segment setting unit that sets a plurality of second line segments which connect between the point selected by the point selection unit and each of both the end points in order;

a direction revision unit that revises directions of each of the second line segments set by the line segment setting unit, so that each angle which is formed between each of the second line segments and a predetermined direction set in advance becomes an integer multiple of an unit angle set in advance;

an intersection point detection unit that obtains a point of intersection on which respective prolonged line segments obtained by prolonging the second line segments of which the direction has been revised by the direction revision unit are intersected each other; and

a length revision unit that revises a length of each of the second line segments, so as to connect together the point of intersection obtained by the intersection point detection unit and one of the end points or one of the points selected by the point selection unit; and

wherein;

the abridged map generation unit generates the abridged map by simplifying the shape of the link or link series, by using each of the second line segments of which the length are revised by the length revision unit.

11. An abridged map generating apparatus according to claim 10, wherein:

the point selection unit selects the point which is furthest from a first line segment which connects between both the end points among points set in advance upon the link.

12. An abridged map generating apparatus according to claim 11 wherein:

the point selection unit further selects points which are furthest from third line segments which connect between both the end points and the selected point respectively among points set in advance upon the link.

13. An on-vehicle information terminal, comprising:

an abridged map generating apparatus according to claim 1;

and

a display control unit that causes an abridged map generated by the abridged map generating apparatus to be displayed upon a display monitor.

14. An abridged map distribution system, comprising:

an abridged map generating apparatus according to claim 1;

a distribution apparatus that distributes an abridged map generated by the abridged map generating apparatus; and

a navigation apparatus that receives the abridged map distributed by the distribution apparatus.

15. An abridged map generating method for generating an abridged map in which road shapes have been simplified, the method comprising:

simplifying a shape of a link or link series while fixing positions of both end points of the link or the link series made by lining up a plurality of links based upon road map data which specifies the shapes of roads by the shapes of links which are set for each predetermined road section.