Route searching device

• US 20040088109A1
• Filed: 07/31/2003
• Published: 05/06/2004
• Est. Priority Date: 01/31/2001
• Status: Active Grant

• Current Assignee: Clarion Co., Ltd. (Faurecia SA)
• Original Assignee: Clarion Co., Ltd. (Faurecia SA)
• Inventors: Miyashita, Jun
• Granted Patent: US 7,546,203 B2
• Time in Patent Office: Days
• US Class Current: 701/210
• CPC Class Codes: G01C 21/34 Route searching; Route guidance

Abstract

A route searching apparatus comprises a processing device that searches a guided route along which a vehicle is to be guided from a current vehicle position to a destination and also searches a detour route for detouring a detour segment set over part of the guided route. The processing device extracts guidance-requiring intersections at which the vehicle needs to be guided to follow a course among intersections on the guided route, sets a segment ending at a guidance-requiring intersection close to the current vehicle position among the guidance-requiring intersections as the detour segment, and searches the detour route for detouring the detour segment.

Claims

1. A route searching apparatus comprising:

a processing device that searches a guided route along which a vehicle is to be guided from a current vehicle position to a destination and also searches a detour route for detouring a detour segment set over part of the guided route, wherein;

the processing device extracts guidance-requiring intersections at which the vehicle needs to be guided to follow a course among intersections on the guided route, sets a segment ending at a guidance-requiring intersection close to the current vehicle position among the guidance-requiring intersections as the detour segment, and searches the detour route for detouring the detour segment.

2. A route searching apparatus according to claim 1, wherein:

the processing device selects an intersection at which a detour starts (hereafter referred to as a detour start intersection) among intersections present within a predetermined segment close to the current vehicle position on the guided route, sets a segment starting at the detour start intersection and ending at a guidance-requiring intersection closest to the current vehicle position among the guidance-requiring intersections as the detour segment, and searches the detour route for detouring the detour segment.

3. A route searching apparatus according to claim 1, wherein:

the processing device detects types of the guidance-requiring intersections based upon roadmap data, selects a guidance-requiring intersection to be set as an end point of the detour segment among the guidance-requiring intersections close to the current vehicle position according to the intersection types, and searches the detour route for detouring the detour segment ending at the selected guidance-requiring intersection.

4. A route searching apparatus according to any of claims 1 through 3, wherein:

if a distance from the current vehicle position to the guidance-requiring intersection set as an end point of the detour segment is smaller than a predetermined lower limit, the processing device sets a segment extending from the current vehicle position to a point on the guided route distanced from the current position by a predetermined value as the detour segment and searches the detour route for detouring the detour segment thus set.

5. A route searching apparatus according to any of claims 1 through 3, wherein:

if a distance from the current vehicle position to the guidance-requiring intersection set as an end point of the detour segment exceeds a predetermined upper limit, the processing device sets a segment extending from the current vehicle position to a point on the guided route distanced from the current vehicle position by a predetermined value as the detour segment and searches the detour route for detouring the detour segment thus set.

6. A route searching apparatus according to any of claims 1 through 5, wherein:

the processing device does not search the detour route if the detour start intersection is not present within a predetermined distance from the current vehicle position.

7. A route searching apparatus according to any of claims 1 through 5, wherein:

the processing device does not search the detour route if there is no intersection at which the vehicle can return to the guided route between the guidance-requiring intersection set as an end point of the detour segment and the destination.

8. A route searching apparatus according to any of claims 1 through 5, wherein:

the processing device does not search the detour route if an end point of the detour segment is beyond the destination.

9. A method for executing a route search comprising:

searching a guided route along which a vehicle is to be guided from a current vehicle position to a destination;

extracting guidance-requiring intersections at which the vehicle needs to be guided to follow a course among intersections present on the guided route; and

searching a detour route for detouring a detour segment ending at a guidance-requiring intersection close to the current vehicle position among the guidance-requiring intersections.

10. A computer readable computer program product containing a route search program, the route search program comprising:

an instruction for searching a guided route along which a vehicle is to be guided from a current vehicle position to a destination;

an instruction for extracting guidance-requiring intersections at which the vehicle needs to be guided to follow a course among intersections present on the guided route; and

an instruction for searching a detour route for detouring a detour segment ending at a guidance-requiring intersection close to the current vehicle position among the guidance-requiring intersections.

11. A computer readable computer program product according to claim 10, wherein:

the computer readable computer program product is a recording medium on which the route search program is recorded.

12. A computer readable computer program product according to claim 10, wherein:

the computer readable computer program product is a carrier wave in which the route search program is embodied as a data signal.