Navigation system and program

• US 20060271284A1
• Filed: 04/04/2006
• Published: 11/30/2006
• Est. Priority Date: 04/06/2005
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Shibata, Hirokazu, Watanabe, Yoshinori, Kawakami, Hidehiko, Taguchi, Kiyotaka, Abo, Masatoshi
• Granted Patent: US 7,395,152 B2
• Time in Patent Office: Days
• US Class Current: 701/209
• 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

A map image showing a current position and its surroundings, a route, and an arrow are displayed and superimposed on one another. The arrow has a base indicating the current position and a length indicating a predetermined distance along the route. The arrow has the transparency adjusted to be half transparent to make the map image and route discernible. The arrow moves along with the current position as a vehicle travels on the route. When the route is rectilinear, the shape and length of the arrow do not change. When the route is turned left at an intersection, the arrowhead is turned left after reaching the intersection. Since the arrow is displayed along the route, the arrowhead is disposed on a road to which the vehicle is brought by a left turn made on a road on which the base is disposed.

Claims

1. A navigation system comprising:

a guide unit including a display on which at least an image is displayed;

a map data acquisition unit that acquires map data;

a current position identification unit that identifies a current position of a vehicle;

a route obtaining unit that obtains a route to a destination; and

a guide control unit that uses the map data acquired by the map data acquisition unit to display on the display a map image which shows the current position identified by the current position identification unit and its surroundings, and that displays the route, which is recognized by the route obtaining unit, while superimposing the route on the map image, wherein

the guide control unit displays an arrow, which includes

a base that indicates the current position identified by the current position identification unit,

an arrowhead that points out a forward position separated by a predetermined distance along the route, and

a segment leading to the arrowhead, while superimposing the arrow on the map image on which the route is superimposed.

2. The navigation system according to claim 1, wherein

when the guide control unit superimposes the arrow on the map image on which the route is superimposed,

the guide control unit displays the arrow so that the map image and route are discernible.

3. The navigation system according to claim 1, wherein

the guide control unit

is able to display on the display a map image produced in a different reduction scale,

determines a distance from the base of the arrow to the arrowhead thereof, based on the reduction scale employed in the map image displayed, and

displays the arrow indicating the determined distance.

4. The navigation system according to claim 1, wherein:

the guide unit includes a loudspeaker via which sounds are outputted; and

when the current position identified by the current position identification unit approaches a position that is separated by a predetermined audio guide distance from a predetermined audio guide point on the route,

the guide control unit

gives predetermined audio guide via the loudspeaker,

determines the distance between the base of the arrow and the arrowhead thereof, based on the audio guide distance, and

displays the arrow indicating the determined distance.

5. The navigation system according to claim 4, wherein

when the current position approaches a position that is separated by the predetermined audio guide distance from the audio guide point,

the guide control unit

gives the predetermined audio guide via the loudspeaker,

determines the distance between the base of the arrow and the arrowhead thereof, based on the audio guide distance,

displays the arrow indicating the determined distance, and

also displays the arrow in a modified form.

6. The navigation system according to claim 1, wherein

the guide control unit displays the arrow by varying color or shape of a portion of the arrow between the base of the arrow and the arrowhead thereof, or by graduating the portion of the arrow between the base of the arrow and the arrowhead thereof.

7. The navigation system according to claim 6, wherein:

only when the arrowhead reaches a predetermined guide point other than a destination on the route,

the guide control unit

varies at predetermined intervals the color or shape of the portion of the arrow between the base of the arrow and the arrowhead thereof, or

graduates at predetermined intervals the portion of the arrow between the base of the arrow and the arrowhead thereof, and then

displays the arrow; and

when the base of the arrow passes the predetermined guide point other than the destination,

the guide control unit

cancels the varying of the color or shape or cancels the graduating at predetermined intervals, and then

displays the arrow.

8. The navigation system according to claim 1, wherein:

when the arrowhead reaches a predetermined guide point other than a destination on the route,

the guide control unit

adjusts a length of the arrow so that the arrowhead overpasses the guide point and

displays the arrow; and

when the arrowhead reaches the destination on the route,

the guide control unit

adjusts the length of the arrow so that the arrowhead is locked at the destination and

displays the arrow.

9. The navigation system according to claim 8, wherein:

when the arrowhead reaches a predetermined guide point other than a destination on the route,

the guide control unit decides whether a distance from the guide point, regarded as a reference, to a nearest guide point falls below a predetermined distance;

supposing that the distance falls below the predetermined distance, the guide control unit adjusts the length of the arrow so that the arrowhead overpasses the guide point;

assuming that forward guide points are handled in an identical manner, the guide control unit orderly decides whether a distance between adjoining guide points satisfies a condition that the distance between adjoining guide points falls below the predetermined distance; and

supposing that the condition is satisfied continuously, the guide control unit adjusts the length of the arrow so that the arrowhead overpasses the respective guide points concerned.

10. The navigation system according to claim 1, wherein:

when a predetermined guide point other than a destination on the route is displayed on a display screen of the display, the guide control unit adjusts a length of the arrow so that the arrowhead overpasses the guide point; and

when the destination on the route is displayed on the display screen of the display, the guide control unit adjusts the length of the arrow so that the arrowhead is locked at the destination.

11. The navigation system according to claim 10, wherein

when the predetermined guide point is a point of warning for a curve, the guide control unit adjusts the length of the arrow so that the arrow covers a whole of the curve from an initial point of the curve to a terminal point thereof.

12. The navigation system according to claim 1, wherein

when the arrow exists at a predetermined guide point on the route, the guide control unit superimposes a predetermined mark, which represents the guide point, on the arrow.

13. The navigation system according to claim 12, wherein

the guide control unit adjusts transparency of the predetermined mark, which represents the guide point, so that the route is discernible through at least part of the predetermined mark, and superimposes the predetermined mark and arrow on the route.

14. The navigation system according to claim 13, wherein:

when the predetermined guide point is a junction, the guide control unit highlights a joining road; and

when the predetermined guide point is a railway crossing, the guide control unit highlights the railway crossing.

15. The navigation system according to claim 1, wherein

the map data acquired by the map data acquisition unit includes information on attributes of a road such as a road type and a number of lanes,

further comprising

a relationship-of-correspondence memory unit in which a relationship of correspondence between information on the attributes of each road and information on a degree of change to which a length of the arrow should be changed is stored, wherein

the guide control unit

reads the information on a degree of change, to which the length of the arrow should be changed, from the relationship-of-correspondence memory unit in association with the information on the attributes of a road on which the current position identified by the current position identification unit exists,

adjusts the length of the arrow based on the information on the degree of change to which the length of the arrow should be changed, and

displays the arrow.

16. The navigation system according to claim 1, wherein

the map data acquired by the map data acquisition unit includes information on attributes of a road such as a road type and a road width,

further comprising

a relationship-of-correspondence memory unit in which a relationship of correspondence between information on the attributes of each road and information on the degree of change to which a thickness of the arrow should be changed is stored, wherein

the guide control unit

reads the information on the degree of change, to which the thickness of the arrow should be changed, from the relationship-of-correspondence memory unit in association with the information on the attributes of a road on which the current position identified by the current position identification unit exists,

adjusts the thickness of the arrow based on the information on the degree of change to which the thickness of the arrow should be changed, and

displays the arrow.

17. The navigation system according to claim 1, wherein

when an attempt is made to display the arrow having a predetermined length or the arrow whose length is adjusted in a predetermined manner, supposing the arrowhead comes out of a display screen of the display, the guide control unit adjusts the length of the arrow to confine the arrowhead within the display screen, and displays the arrow.

18. The navigation system according to claim 1, wherein

assuming that an advancing direction is changed at a nearest guide point among all predetermined guide points other than a destination on the route, when the arrowhead does not reach the guide point, the guide control unit displays the arrow together with a representation of the advancing direction.

19. The navigation system according to claim 1, wherein

when the arrow is linearly displayed or when the arrow is displayed with a direction thereof changed at a predetermined guide point other than a destination on the route, the guide control unit extends control so that the advancing direction of the vehicle corresponds to a predetermined direction on a screen.

20. The navigation system according to claim 1, wherein:

when the arrow is linearly displayed, the guide control unit extends control so that the arrowhead is oriented in a predetermined direction on a screen; and

when the arrow is displayed with a direction thereof changed at a predetermined guide point other than a destination on the route,

the guide control unit extends control so that when the current position approaches the predetermined guide point with a predetermined distance between them, the arrowhead is oriented in the predetermined direction on the screen.

21. The navigation system according to claim 1, wherein:

when the arrow is linearly displayed, the guide control unit extends control so that the arrowhead is oriented in a predetermined direction on a screen; and

when the arrow is displayed with the direction thereof changed at a predetermined guide point other than a destination on the route,

the guide control unit extends control so that when the current position overpasses the predetermined guide point by a predetermined distance, the arrowhead is oriented in the predetermined direction on the screen.

22. The navigation system according to claim 1, wherein:

when the arrow is linearly displayed, the guide control unit extends control so that the arrowhead is oriented in a predetermined direction on a screen; and

when the arrow is displayed with a direction thereof changed at a predetermined guide point other than a destination on the route,

the guide control unit extends control so that a composite vector of a unit directional vector, of which direction corresponds to an approaching direction in which the vehicle is driven to approach the predetermined guide point on the route, and a unit directional vector, of which direction corresponds to a receding direction in which the vehicle is driven to recede from the predetermined guide point on the route, is oriented in the predetermined direction on the screen during a period from when the current position approaches the predetermined guide point with a predetermined distance between them to when the current position overpasses the predetermined guide point by the predetermined distance.

23. The navigation system according to claim 1, wherein

the arrow is moved synchronously with a shift of the current position.

24. The navigation system according to claim 1, wherein

the display included in the guide unit is interposed between at least two indicators that display mutually different indications.

25. A computer program product stored in a computer readable medium and intended to realize the guide control unit included in the navigation system according to claim 1.