TRAJECTORY DISPLAY DEVICE

• US 20110208422A1
• Filed: 02/18/2011
• Published: 08/25/2011
• Est. Priority Date: 02/22/2010
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: HAYASHI, Mitsuhisa, SAWADA, Kiyohiko, NAKANO, Mikiya, TSUJI, Kenji
• Granted Patent: US 8,731,825 B2
• Time in Patent Office: Days
• US Class Current: 701/206
• CPC Class Codes: G01C 21/36 Input/output arrangements for on-board computers
• 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 trajectory display device includes: a display element; a current position detector; a memory for storing the current position successively; and a position determination unit for determining a plurality of certain actual distance trajectory points and a plurality of direction change points based on position data stored in the memory. The certain actual distance trajectory points are arranged at every actual distance defined by a scale of a map. The moving body changes a moving direction at each direction change point. The display element displays the trajectory including the certain actual distance trajectory points and the direction change points, which is overlapped over the map.

Claims

1. A trajectory display device comprising:

a display element for displaying a trajectory of a moving body and a map;

a current position detector for detecting a current position of the moving body successively;

a memory for storing the current position successively so that a plurality of position data is stored; and

a position determination unit for determining a plurality of certain actual distance trajectory points and a plurality of direction change points based on the position data stored in the memory,

wherein the certain actual distance trajectory points are arranged at every actual distance,

wherein the actual distance is defined by a first scale of the map displayed on the display element in such a manner that the actual distance in case that the first scale of the map is small is longer than the actual distance in case that the first scale of the map is large,

wherein the moving body changes a moving direction at each direction change point, and

wherein the display element displays the trajectory including the certain actual distance trajectory points and the direction change points, which is overlapped over the map.

2. The trajectory display device according to claim 1,

wherein the position determination unit selects a part of the position data stored in the memory as candidate points of each direction change point,

wherein a distance between two adjacent candidate points is narrower than a distance between two adjacent certain actual distance trajectory points,

wherein the position determination unit further selects three successive candidate points, and

wherein the position determination unit determines based on a traveling direction change at a center of the three successive candidate points whether the center of the three successive candidate points is the direction change point.

3. The trajectory display device according to claim 2,

wherein the current position detector detects the current position at predetermined time intervals,

wherein one end of the three successive candidate points and the center of the three successive candidate points provide a first vector, and the center of the three successive candidate points and the other end of the three successive candidate points provide a second vector, and

wherein the position determination unit determines that the center of the three successive candidate points is the direction change point when an angle between the first vector and the second vector is equal to or larger than a predetermined threshold.

4. The trajectory display device according to claim 1,

wherein the position determination unit does not determine the direction change points when the first scale of the map is equal to or smaller than a predetermined scale.

5. The trajectory display device according to claim 4,

wherein the display element displays the trajectory including only the certain actual distance trajectory points when the first scale of the map is equal to or smaller than a predetermined scale.

6. The trajectory display device according to claim 1,

wherein the position determination unit defines a second scale, which is larger by one step than the first scale,

wherein the position determination unit selects a part of the position data stored in the memory,

wherein positions in the part of the position data are arranged at every actual distance, which is defined by the second scale, and

wherein the position determination unit determines each direction change point based on the part of the position data.

7. A trajectory display device comprising:

a display element for displaying a trajectory of a moving body and a map;

a current position detector for detecting a current position of the moving body successively;

a memory for storing the current position successively so that a plurality of position data is stored; and

a position determination unit for determining a plurality of certain display distance trajectory points based on the position data stored in the memory,

wherein the certain display distance trajectory points are arranged at every actual distance corresponding to a display distance,

wherein the display element displays the trajectory including the certain display distance trajectory points, which is overlapped over the map, and

wherein the display distance is defined by a distance of a display screen of the display element in such a manner that an user recognizes the trajectory prepared by the display distance.

8. The trajectory display device according to claim 7,

wherein the position determination unit calculates the actual distance according to the display distance and a scale of the map displayed on the display element, and

wherein the display distance is preliminary determined according to dimensions of the display screen.

9. The trajectory display device according to claim 7,

wherein, when the trajectory is prepared by the display distance, the user can easily distinguish the trajectory.

10. The trajectory display device according to claim 7,

wherein the position determination unit determines a plurality of direction change points based on the plurality of certain display distance trajectory points,

wherein the moving body changes a moving direction at each direction change point,

wherein the position determination unit determines a first part of the certain display distance trajectory points, which are disposed in a region within a circle around each direction change point as a center of the circle having a predetermined diameter,

wherein the position determination unit determines a second part of the certain display distance trajectory points, which are disposed outside of the region, and

wherein the position determination unit changes the display distance of the second part of the certain display distance trajectory points to be longer than the display distance of the first part of the certain display distance trajectory points.

11. The trajectory display device according to claim 10,

wherein the position determination unit maintains the display distance of the first part of the certain display distance trajectory points.

12. The trajectory display device according to claim 10,

wherein the position determination unit maintains the display distance of the second part of the certain display distance trajectory points, and

wherein the position determination unit changes the display distance of the first part of the certain display distance trajectory points to be shorter than the display distance of the second part of the certain display distance trajectory points.

13. The trajectory display device according to claim 10,

wherein the position determination unit selects a part of the position data stored in the memory as candidate points of each direction change point,

wherein a distance between two adjacent candidate points is narrower than a distance between two adjacent certain display distance trajectory points,

wherein the position determination unit further selects three successive candidate points, and

wherein the position determination unit determines based on a traveling direction change at a center of the three successive candidate points whether the center of the three successive candidate points is the direction change point.

14. The trajectory display device according to claim 13,

wherein the current position detector detects the current position at predetermined time intervals,

wherein one end of the three successive candidate points and the center of the three successive candidate points provide a first vector, and the center of the three successive candidate points and the other end of the three successive candidate points provide a second vector, and

wherein the position determination unit determines that the center of the three successive candidate points is the direction change point when an angle between the first vector and the second vector is equal to or larger than a predetermined threshold.