Navigation apparatus and navigation method

• US 20030154023A1
• Filed: 02/03/2003
• Published: 08/14/2003
• Est. Priority Date: 02/14/2002
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Utsumi, Koichiro
• Granted Patent: US 6,807,482 B2
• Time in Patent Office: Days
• US Class Current: 701/209
• CPC Class Codes: G01C 21/34 Route searching; Route guidance

Abstract

A navigation apparatus includes a notification unit for, in a case where a route searching unit cannot carry out route searching for an area in the vicinity of a destination, notifying users that the route searching unit cannot carry out route searching for the area in the vicinity of the destination when a physical quantity associated with a relationship between the current position of a vehicle determined by a current position determination unit and the destination is less than a preset reference value.

Claims

1. A navigation apparatus comprising:

a current position determination means for determining a current position of a vehicle;

a storage means for storing map data;

a route searching means for searching for a route from a place of departure to a destination by referring to the map data stored in said storage means;

a display means for displaying the route searched for by said route searching means; and

a notification means for, in a case where said route searching means cannot carry out route searching for an area in the vicinity of the destination, notifying users that said route searching means cannot carry out route searching for the area in the vicinity of the destination when a physical quantity associated with a relationship between the current position of the vehicle determined by said current position determination means and the destination is less than a preset reference value.

2. The navigation apparatus according to claim 1, wherein in a case where said route searching means cannot carry out route searching for an area in the vicinity of a via point, said notification means notifies users that said route searching means cannot carry out route searching for the area in the vicinity of the via point when a quantity associated with a relationship between the current position of the vehicle determined by said current position determination means and the via point is less than a preset reference value.

3. The navigation apparatus according to claim 1, wherein said physical quantity is either a distance between the current position of the vehicle determined by said current position determination means and the destination or a time required for the vehicle to travel from the current position of the vehicle to the destination.

4. The navigation apparatus according to claim 2, wherein said physical quantity is either a distance between the current position of the vehicle determined by said current position determination means and the via point or a time required for the vehicle to travel from the current position of the vehicle to the via point.

5. The navigation apparatus according to claim 1, further |comprising a setting means for accepting an update of the preset reference value.

6. The navigation apparatus according to claim 5, wherein said setting means accepts an update of the preset reference value only when both the current position of the vehicle and the destination or the via point are not displayed simultaneously on an on-screen map.

7. The navigation apparatus according to claim 1 , wherein said notification means also makes a notification about a reason why said route searching means cannot carry out route searching for an area in the vicinity of the destination when making a notification that said route searching means cannot carry out route searching for the area.

8. The navigation apparatus according to claim 7, wherein said notification means also makes a notification that said route searching means cannot carry out route searching for an area in the vicinity of the destination and a notification about a reason why said route searching means cannot carry out route searching for the area when said route searching means finishes searching for the route.

9. The navigation apparatus according to claim 1, further comprising a means for searching for a facility located in the vicinity of the destination or a via point when said route searching means cannot carry out route searching for an area in the vicinity of the destination or the via point.

10. The navigation apparatus according to claim 1, wherein said notification means displays notifications on a display.

11. The navigation apparatus according to claim 1, wherein said notification means outputs notifications by voice from a speaker.

12. The navigation apparatus according to claim 1, further comprising a means for enabling or disabling said notification means.

13. A navigation method comprising the steps of:

determining a current position of a vehicle;

searching for a route from a place of departure to a destination by referring to map data;

displaying the route searched for; and

in a case where route searching cannot be carried out for an area in the vicinity of the destination, notifying users that route searching cannot be carried out for the area in the vicinity of the destination when a physical quantity associated with a relationship between the current position of the vehicle and the destination is less than a preset reference value.

14. The navigation method according to claim 13, wherein said physical quantity is either a distance between the current position of the vehicle determined by said current position determination means and the destination or a time required for the vehicle to travel from the current position of the vehicle to the destination.