Method and apparatus for drawing a map for a navigation system

• US 5,925,091 A
• Filed: 05/28/1996
• Issued: 07/20/1999
• Est. Priority Date: 06/12/1995
• Status: Expired due to Term

• Current Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Original Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Inventors: Ando, Katsunori
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US08/654,421
• Time in Patent Office: 1,148 Days
• Field of Search: 364/443, 364/444.2, 364/449.6, 364/449.4, 364/449.1, 364/449, 364/460, 340/990, 340/995, 340/905, 340/988, 340/636, 395/132, 395/137, 395/138, 395/139, 395/173, 342/451, 342/457, 342/452, 73/178 R, 701/200, 701/208, 701/209, 701/210, 701/211, 701/212, 701/117, 345/428, 345/440-443, 345/121, 345/133, 345/515, 345/968
• US Class Current: 701/212
• CPC Class Codes: G01C 21/3664 Details of the user input interface, e.g. buttons, knobs or sliders, including those provided on a touch screen; remote controllers; input using gestures
• 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

In a vehicle navigation method and apparatus for drawing a map in which the scale of a displayed map is reduced to display a second wide-area map, an image of a presently-traveled road is drawn on the display so it is superimposed on the wide-area map, even if the wide-area map otherwise does not show the presently-traveled road. When the scale of the presently displayed map is reduced to instead display the wide-area map, a determination is made as to whether the presently-traveled road is displayed. If the presently-traveled road is not displayed, an image of the presently-traveled road is generated from map information pertaining to the presently-traveled road and the image is displayed so it is superimposed on the wide-area map.

Claims

1. A map drawing method in which a map showing a present vehicle position is displayed while a mark representing the vehicle position is displayed on the map, the method comprising the steps of:

determining whether a presently-traveled road is displayed on the map;

generating an image of the presently-traveled road if the presently-traveled road is not already displayed on the map; and

displaying the image of the presently-traveled road by superimposing the generated image of the presently-traveled road on the displayed map that did not otherwise display the presently-traveled road.

2. A map drawing method according to claim 1, further comprising storing map data including at least road data, wherein the stored map data includes a figure attribute.

3. A map drawing method according to claim 1, wherein the step of determining includes determining whether the presently-traveled road is displayed according to whether the vehicle position is on a presently displayed road or whether the vehicle position is within a predetermined distance of a presently displayed road taking into consideration a vehicle position error.

4. A map drawing method according to claim 3, wherein the step of determining includes determining according to whether the vehicle position is on a road expressed by figure data.

5. A map drawing method according to claim 1, wherein if the presently-traveled road branches before reaching a road displayed on the map, the branch roads are displayed.

6. A map drawing method according to claim 1, wherein the step of generating an image includes accessing a map buffer and further includes the steps of:

writing data of a second map containing the presently-traveled road into the map buffer; and

generating the image of the presently-traveled road from the data written into the map buffer.

7. A map drawing method according to claim 6, wherein if a scale of the di splayed map is 1/n while the scale of the second map is 1/m where m<

n, the image of the presently-traveled road is displayed at a scale of m/n.

8. A map drawing method according to claim 7, wherein the image of the presently-traveled road is adjusted if an amount of the data exceeds a predetermined value.

9. A map drawing method according to claim 1, wherein the step of generating an image includes accessing a memory and includes the steps of:

obtaining data defining a road passing the vehicle position from road layer data, and storing the obtained data in the memory; and

generating the image of the presently-traveled road from the stored data.

10. A map drawing method according to claim 1, wherein the step of determining occurs upon selecting a change of a scale of the displayed map.

11. A map drawing method in which a map showing a vehicle position is displayed while a mark representing the vehicle position is displayed on the map, the method comprising the steps of:

determining whether a presently-traveled road is displayed according to whether the vehicle position is on a presently displayed road or whether the vehicle position is within a predetermined distance of a presently displayed road;

generating an image of the presently-traveled road using data pertaining to the presently-traveled road if the presently-traveled road is not already displayed on the map; and

displaying the image of the presently-traveled road on the display screen by superimposing the image of the presently-traveled road on the displayed map that did not otherwise display the presently-traveled road.

12. A map drawing method according to claim 11, wherein the step of determining takes into consideration a vehicle position error.

13. A map drawing method according to claim 11, wherein the step of generating an image includes accessing a map buffer and further includes the steps of:

writing data of a second map showing the presently-traveled road into the map buffer; and

generating the image of the presently-traveled road from the data written into the map buffer.

14. A map drawing method according to claim 13, wherein if a scale of the map is 1/n while the scale of the second map is 1/m where m<

n, the image of the presently-traveled road is displayed at a scale of m/n.

15. A map drawing method according to claim 14, wherein the image of the presently-traveled road is adjusted if an amount of the data exceeds a predetermined value.

16. A map drawing method according to claim 11, wherein the step of generating an image includes accessing a memory and further includes the steps of:

obtaining data defining a road passing the vehicle position, and storing the obtained data in the memory; and

generating the image of the presently-traveled road from the stored data.

17. A navigation apparatus in which a map showing a present vehicle position is displayed while a mark representing the vehicle position is displayed on the map, the apparatus comprising:

a traveled road image generating section which determines whether a presently-traveled road is displayed according to whether the vehicle position is on a presently displayed road or whether the vehicle position is within a predetermined distance of a presently displayed road, the traveled road image generating section generating an image of the presently-traveled road using data pertaining to the presently-traveled road, if the presently-traveled road is not already displayed on the map; and

an image synthesis section coupled to the traveled road image generating section and which displays the image of the presently-traveled road by superimposing the image of the presently-traveled road on the displayed map that did not otherwise display the presently-traveled road.

18. A navigation apparatus according to claim 17, wherein if the presently-traveled road branches before reaching a road displayed on the map, the branch roads are displayed.

19. A navigation apparatus according to claim 17, wherein the traveled road image generating section includes a map buffer, and

wherein the traveled road image generating section writes data of a second map showing the presently-traveled road into the map buffer and generates the image of the presently-traveled road from the data written into the map buffer.

20. A navigation apparatus according to claim 19, wherein if a scale of the displayed map is 1/n while the scale of the second map is 1/m where m<

n, the image of the presently-traveled road is displayed at a scale of m/n.

21. A navigation apparatus according to claim 20, wherein the image of the presently-traveled road is adjusted if an amount of the data exceeds a predetermined value.

22. A navigation apparatus according to claim 17, wherein the traveled road image generating section includes a memory, and

wherein the traveled road image generating section obtains data defining a road passing the vehicle position, stores the obtained data in the memory, and generates the image of the presently-traveled road from the stored data.

23. A map drawing method in which a map showing a present vehicle position is displayed while a mark representing the vehicle position is displayed on the map, the method comprising the steps of:

determining whether a presently-traveled road is displayed on the map;

displaying the image of the presently-traveled road by superimposing the generated image on the displayed map;

wherein the step of generating an image includes accessing a map buffer and further includes the steps of;

writing data of a second map containing the presently-traveled road into the map buffer; and

generating the image of the presently-traveled road from the data written into the map buffer; and

wherein of a scale of the displayed map is 1/n while the scale of the second map is 1/m where m<

n, the image of the presently-traveled is displayed at a scale of m/n.

24. A map drawing method in which a map showing a vehicle position is displayed while a mark representing the vehicle position is displayed on the map, the method comprising the steps of:

determining whether a presently-traveled road is displayed according to whether the vehicle position is on a presently displayed road or whether the vehicle position is within a predetermined distance of a presently displayed road;

generating an image of the presently-traveled road using data pertaining to the presently-traveled road if the presently-traveled road is not displayed; and

displaying the image of the presently-traveled road on the display screen by superimposing the image on the displayed map;

wherein the step of generating an image includes accessing a map buffer and further includes the steps of;

writing data of a second map showing the presently-traveled road into the map buffer; and

generating the image of the presently-traveled road from the data written into the map buffer; and

wherein if a scale of the map is 1/n while the scale of the second map is 1/m where m<

n, the image of the presently-traveled road is displayed at a scale of m/n.

25. A navigation apparatus in which a map showing a present vehicle position is displayed while a mark representing the vehicle position is displayed on the map, the apparatus comprising:

traveled road image generating section which determines whether a presently-traveled road is displayed according to whether the vehicle position is on a presently displayed road, the traveled road image generating section generating an image of the presently-traveled road is not displayed; and

an image synthesis section coupled to the traveled road image generating section and which displays the image of the presently-traveled road by superimposing the image on the displayed map;

wherein the traveled road image generating section includes a map buffer; and

wherein the traveled road image generating section writes data of a second map showing the presently-traveled road into the map buffer and generates the image of the presently-traveled road from the data written into the map buffer; and

wherein if the scale of the displayed map is 1/n while wherein the scale of the second map is 1/m where m<

n, the image of the presently-traveled road is displayed at a scale of m/n.