JPH09325692A - Map displaying method for navigation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the map displaying method for navigation in which a distant map and sky are displayed as a bird's-eye view display and a near map is shown close to the bird's-eye view display. SOLUTION: N perspective points are beforehand set corresponding to the display screen of a map display section 33. Display coordinate sections 27-1 to 27-n calculate display coordinates 1 to n based on coordinate transformation equations 1 to n and transfer the coordinates to coordinate transformation sections 29-1 to 20-n. Then, the sections 29-1 to 29-n read the map data beforehand stored in a map information recording section 23 and convent the data to n sheets of plane perspective drawing corresponding to the n perspective points. Then, a composite section 31 generates a sheet of a display map by composing data 1 on n of the plane perspective drawing subjected to coordinate transformation and the display map from the section 31 is displayed on the screen 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a navigation map display method capable of displaying a plan perspective view after converting map information into a plan perspective view based on the plan perspective method.

[0002]

2. Description of the Related Art As a conventional map display method for a navigation system, a map display method using a top view or a plan perspective view is known. Further, in the "navigation map display device" described in Japanese Patent Application Laid-Open No. 1-263688, as shown in FIG. 16, the display is performed by perspective conversion into a plan perspective view, a spherical perspective view, and a cylindrical-planar composite perspective view. Methods of making maps are known.

Furthermore, in the "display method for a route guidance device for a vehicle" described in Japanese Patent Laid-Open No. 6-273184, as shown in FIG. 17, a cylindrical perspective view is used in the near portion to define a range within a predetermined distance from the current position. In addition to displaying in detail at a certain large scale, a plan perspective view is used for the far part and is displayed at a smaller scale as it goes far beyond a predetermined distance to guide the route of the vehicle traveling from the current location to the destination. It is known to have the advantage of being able to do so.

[0004]

However, FIG.
Also, in the conventional map display method as shown in FIG. 17, since it may be displayed after converting a straight line into a curve, map data that expresses roads and coastlines with a combination of straight lines is used. In such a case, there are problems that roads that did not intersect in the original data will intersect after conversion and that the roads will be displayed as if they were running in the sea.
For example, in general, a straight line forming a road is finer than a straight line forming a coastline, so as shown in FIG.
The road 103 is displayed as a curved line, while the coastline 104 is displayed as a straight line in a form of short-cutting the curved line. Therefore, when the road 103 runs near the coastline 104, the road 103 may be displayed in the sea 105 beyond the coastline 104.

The present invention has been made in view of the above, and an object thereof is to provide a distant map and a sky as a bird's-eye view display, while a near map display can be displayed close to a top view. The purpose is to provide a display method.

[0006]

According to the first aspect of the present invention,
In order to solve the above-mentioned problems, a map display method for navigation, in which map information stored in advance is converted into a plan perspective view based on a plan perspective method, and then the plan perspective view is displayed, wherein n is displayed on the display screen. N perspective viewpoints are provided, the map information stored in advance is used to calculate n coordinate conversion formulas corresponding to n perspective viewpoints based on the planar perspective method, and n coordinate conversion formulas are calculated based on the coordinate conversion formulas. The gist is to convert it into a plan perspective view and synthesize a display map from the n plan perspective views.

In order to solve the above-mentioned problems, the invention according to claim 2 makes it possible to set a parameter for making the joint between adjacent plan perspective views continuous in the coordinate conversion formula. .

In order to solve the above-mentioned problems, a third aspect of the invention is to draw the n plan perspective views separately and then copy the plan perspective views to a display map.

In order to solve the above-mentioned problems, the present invention according to claim 4 synthesizes a display map after clipping the map information stored in advance in a display frame formed by a boundary line between the plan perspective views. The point is to do.

[0010]

As described above, according to the present invention as set forth in claim 1, n pieces of perspectives are provided in the display screen, and the map information stored in advance is n based on the planar perspective method. By calculating n coordinate conversion formulas corresponding to the perspective views, converting them into n plan perspective views based on the coordinate conversion formulas, and synthesizing a display map from these n plan perspective views, Since the perspective view is displayed, the distant map and the sky can be displayed as a bird's-view display, while the near map display can be displayed close to the top view, for example, the road near the coastline. Even when the vehicle is running, it is possible to prevent an erroneous display process in which the road is displayed in the sea over the coastline.

Further, according to the present invention as set forth in claim 2, the coordinate conversion formula enables setting of parameters for making the joints between the adjacent plan perspective views continuous, thereby making it possible to display adjacent map displays. There is no gap in the map displayed at the border, and
The scale in the lateral direction can be made equal, and the joints are continuous, and as a result, the unnatural appearance can be reduced.

According to the present invention of claim 3, n
After drawing each of the plan perspective views separately, by copying the plan perspective view to the display map, as a display result, the distant map and the sky are displayed as a bird view, while the near map display is a top view. Can be displayed closer to.

Further, according to the present invention, the map information stored in advance is clipped in the display frame formed by the boundary line between the plan perspective views, and the display map is synthesized. For example, even when a straight line representing a road or the sea extends over a plurality of display coordinates, the intersection of the boundary can be interpolated.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the principle of the plane perspective method will be described with reference to FIG. In the figure, 1 is a perspective screen,
2 is a plane projection map. Height y0 above the map plane,
When the point P (x, z) on the plane projection map 2 is viewed with the viewpoint at a distance f from the screen center, the line of sight is the perspective screen 1.
A point Q (xs, ys) intersecting with is a perspective. Here, the perspective Q (xs, ys) is expressed by: xs = xf / (f + z) (Equation 1) ys = y0z / (f + z) (Equation 2)

Next, the structure of the display screen by the plane perspective method will be described with reference to FIG. As shown in the figure, when the plane perspective method is applied, the perspective screen 1 needs precise map data in the area 16, but the map data needs the precision as the distance from the areas 15 and 14 increases. And not to.
Now, if the information of the third layer map 13 of the map data is processed and the entire screen is displayed, it is necessary to process a large amount of information. Therefore, the screen is divided into three horizontal areas 14, 15, 16
Each of them is composed of map data 11, 12, and 13.

Referring to FIG. 2, the map data of the three layers is expressed by the relational expression of the plane perspective method: xs = xf / (f + z) (Equation 1) ys = y0z / (f + z) (Equation 2) , X, z are corrected according to the difference between the current position of the vehicle and the position on the hierarchical map data, which is coordinate-converted according to the current azimuth of the vehicle), whereby each hierarchical map 11, 12, 13 is displayed. Areas 14, 15,
Trapezoids 17, 18 on which the distance becomes smaller on 16
It will be displayed as a part of 19. The data near the vanishing point, which requires a large amount of data, is cut to reduce the data.

The trapezoid 18 obtained by this correction calculation is
For example, as shown in FIG. Here, x and z are original coordinate values. If each hierarchical map data is displayed as actual coordinate values on a flat surface or various curved surfaces, the areas 14, 15, 1
The alignment of the six seams is natural. Further, the calculation of data may be performed only at seams z = 0 to z1, z1 to z2, and z2 to z3.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (First Embodiment) FIG. 4 is a diagram showing a system configuration of a navigation map display device 21 equipped with a navigation map display method according to a first embodiment of the present invention.

As shown in FIG. 4, the navigation map display device 21 has, for example, a CD-ROM, and a map information recording unit for recording map data whose position is represented by using latitude and longitude or map coordinates. 23 and n to display coordinates 1 to n
Display coordinate units 27-1 to 27-n for calculating each of the
Coordinate conversion units 29-1 to 29-n that convert map data from map coordinates to display coordinates, a combining unit 31 that combines the coordinate-converted data 1 to n into one display map, and a display from the combining unit 31. It is composed of a map display unit 33 for displaying a map.
The display coordinate units 27-1 to 27-n and the coordinate conversion unit 29-1 to
29-n and the combining unit 31 may be configured by using the central processing unit 25.

Next, the operation of the navigation map display device 21 will be described with reference to the flowchart shown in FIG.
First, in step S110, since n perspectives are provided in advance in association with the display screen displayed from the map display unit 33, the display coordinate units 27-1 to 27-n display the display coordinates 1 to n.
The coordinate conversion formulas 1 to n are calculated based on (Equation 1) and (Equation 2), and are transferred to the coordinate conversion units 29-1 to 29-n. next,
In step S120, the coordinate conversion units 29-1 to 29-n
The map data previously stored in the map information recording unit 23 is read out and converted into n plan perspective views corresponding to n perspective views. That is, map data is converted from map coordinates to display coordinates based on the calculated coordinate conversion formulas 1 to n.

Next, in step S130, the synthesizing unit 31
Combines one display map from the coordinate-converted plan perspective data 1 to n, and displays the display map from the combining unit 31 on the map display unit 33 in step S140. In this way, by dividing the display screen into a plurality of parts and displaying plan perspective views having different parameters, the map display 35 is a bird's-eye view display that displays the distant map 37 and the sky 39, as shown in FIG. On the other hand, the near map display 41 can be displayed closer to the top view.

(Second Embodiment) A navigation map display method according to a second embodiment of the present invention is installed in the system configuration of a navigation map display device 21 shown in FIG.

In the figure, the display coordinate portions 27-1 to 27-n of the navigation map display device 21 have display coordinates 1 to 1.
When calculating the coordinate conversion formula to n, a parameter setting for making the joint continuous is added.

Next, the operation of the navigation map display device 21 will be described with reference to the flowchart shown in FIG.
First, in step S210, the display coordinate units 27-1 to 27-27.
-n sets the parameters of display coordinates 1 to n in the coordinate conversion formula so that the joints are continuous, and the coordinate conversion unit 2
Hand over to 9-1 to 29-n. In step S220, since n perspectives are provided in advance corresponding to the display screen displayed from the map display unit 33, the display coordinate units 27-1 to 27-27 are provided.
-n calculates the coordinate conversion formulas 1 to n for the display coordinates 1 to n based on (Equation 1) and (Equation 2), and the coordinate conversion units 29-1 to 29-n
Hand over to

Next, in step S230, the coordinate conversion units 29-1 to 29-n read out the map data stored in advance in the map information recording unit 23 and correspond to the n perspective viewpoints. Convert to a plan perspective view. That is, map data is converted from map coordinates to display coordinates based on the calculated coordinate conversion formulas 1 to n. Next, in step S240, the combining unit 3
Reference numeral 1 synthesizes one display map from the coordinate-converted plan perspective view data 1 to n. In step S250, the synthesis unit 31
The display map from is displayed on the map display unit 33. here,
The features of the navigation map display device 21 will be described with reference to FIGS. FIG. 8 (a)
FIG. 8 is a diagram of adjacent planar perspective maps 51 and 53 viewed from the lateral direction of map coordinates on the map displayed by the map display unit 33, and FIG. 8B is a diagram viewed from directly above the map coordinates. is there.

As shown in FIG. 8A, the plane perspective map 5 is shown.
A plane 59 including a perspective point 55 and a boundary line 57 of 1 and a plane 6 including a perspective point 61 and a boundary line 63 of the planar perspective map 53.
The intersection line 67P with 5 is on the map plane 67, and FIG.
As shown in (b), the line connecting the transparent viewpoint 55 and the both ends of the boundary line 57 and the line connecting the transparent viewpoint 61 and the both ends of the boundary line 63 intersect each other on the intersection line 67P. As a result, as shown in FIG. 9, since the map displayed at the boundary between the map display 35 and the map display 41 is not displaced and the scales in the horizontal direction are the same, the joints are continuous, As a result, it is possible to reduce the discomfort in appearance.

(Third Embodiment) FIG. 10 is a diagram showing a system configuration of a navigation map display device 21 equipped with a navigation map display method according to a third embodiment of the present invention.

In the figure, the navigation map display device 21 is characterized by having drawing units 71-1 to 71-n for separately drawing the map information converted by the coordinate conversion units 29-1 to 29-n. And

Next, the operation of the navigation map display device 21 will be described with reference to the flowchart shown in FIG. First, in step S310, since n perspectives are provided in advance corresponding to the display screen displayed from the map display unit 33, the display coordinate units 27-1 to 27-n display coordinate 1
Coordinate conversion formulas 1 to n for ~ n are calculated based on (Equation 1) and (Equation 2), and passed to the coordinate conversion units 29-1 to 29-n.

Next, in step S320, the coordinate conversion units 29-1 to 29-n read out the map data stored in advance in the map information recording unit 23 and make n pieces corresponding to n perspectives. Convert to a plan perspective view. That is, map data is converted from map coordinates to display coordinates based on the calculated coordinate conversion formulas 1 to n. Next, in step S330, the drawing unit 7
1-1 to 71-n individually draw the map data 1 to n coordinate-converted by the coordinate converters 29-1 to 29-n, respectively. In step S340, the synthesizing unit 31 synthesizes the map data 1 to n of the drawn individual plan perspective views into one display map, and in step S350, the display map from the synthesizing unit 31 is displayed on the map display unit 33. To do.

As a result, as shown in FIG. 12, the distance map 37 and the near map 41 can be individually drawn and then combined, and a straight line representing the road 43 or the sea 45 can be displayed in a plurality of display coordinates. The straight line can be displayed as a polygonal line that bends at the boundary of a plurality of display coordinates even when the display line extends over.

(Fourth Embodiment) FIG. 13 is a diagram showing a system configuration of a navigation map display device 21 equipped with a navigation map display method according to a fourth embodiment of the present invention.

In the figure, the navigation map display device 21 includes a display coordinate unit 27-1 to 27-n and a coordinate conversion unit 2.
Between 9-1 to 29-n, clipping units 73-1 to 73-n for clipping the pre-stored map information are included in the display frame formed by the boundary line between the plan perspective views. And

Next, the operation of the navigation map display device 21 will be described with reference to the flowchart shown in FIG. First, in step S410, since n perspectives are provided in advance corresponding to the display screen displayed from the map display unit 33, the display coordinate units 27-1 to 27-n display coordinate 1
The coordinate conversion formulas 1 to n to ~ n are calculated based on (Equation 1) and (Equation 2), and are passed to the clipping units 73-1 to 73-n.

Next, in step S420, the clipping units 73-1 to 73-n perform clipping at the boundary of the map data, add interpolation points, and send to the coordinate conversion units 29-1 to 29-n. Next, in step S430, the coordinate conversion unit 2
9-1 to 29-n read map data stored in the map information recording unit 23 in advance and convert it into n plan perspective views corresponding to n perspectives. That is, map data is converted from map coordinates to display coordinates based on the calculated coordinate conversion formulas 1 to n.

Next, in step S440, the synthesizing unit 31
Combines one display map from the coordinate-converted plan perspective data 1 to n, and displays the display map from the combining unit 31 on the map display unit 33 in step S450. As shown in FIG. 15, it is determined whether or not the line or polygon to be drawn crosses the boundary 73, and if it crosses the boundary 73, an interpolation point is set at the intersection of the line or polygon and the boundary 73. By providing 75, the intersection of the boundary can be interpolated even when the straight line expressing the road 43 or the sea 45 spans a plurality of display coordinates.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the principle of a plane perspective method.

FIG. 2 is a diagram for explaining a configuration of a display screen by a plane perspective method.

FIG. 3 is a diagram showing a trapezoid 18 obtained by correction calculation.

FIG. 4 is a diagram showing a system configuration of a navigation map display device 21 equipped with the navigation map display method according to the first embodiment of the present invention.

FIG. 5 is a flowchart for explaining the operation of the navigation map display device 21.

FIG. 6 is a display example of the first embodiment.

FIG. 7 is a flowchart for explaining the operation of the navigation map display device 21.

FIG. 8 is a diagram illustrating a second embodiment.

FIG. 9 is a display example of the second embodiment.

FIG. 10 is a diagram showing a system configuration of a navigation map display device 21 equipped with a navigation map display method according to a third embodiment of the present invention.

11 is a flowchart for explaining the operation of the navigation map display device 21. FIG.

FIG. 12 is a display example of the third embodiment.

FIG. 13 is a diagram showing a system configuration of a navigation map display device 21 equipped with a navigation map display method according to a fourth embodiment of the present invention.

FIG. 14 is a flowchart for explaining the operation of the navigation map display device 21.

FIG. 15 is a display example of the fourth embodiment.

FIG. 16 is a conventional display map.

FIG. 17 is a display map using a conventional cylindrical perspective view and a plan perspective view.

FIG. 18 is a diagram showing a road displayed in the sea across a coastline as a conventional display map.

[Explanation of symbols]

 23 map information recording unit 27-1 to 27-n display coordinate unit 29-1 to 29-n coordinate conversion unit 31 combining unit 33 map display unit

Claims (4)

[Claims] 1. A navigation map display method for displaying pre-stored map information after converting the pre-stored map information into a plan perspective view based on the plan perspective method. A perspective is provided, and the map information stored in advance is used to calculate n coordinate conversion formulas corresponding to n perspectives based on the planar perspective method, and n planar perspectives are calculated based on the coordinate conversion formulas. A method for displaying a map for navigation, characterized by converting the map into a diagram and synthesizing a display map from the n plan perspective views. 2. The method for displaying a map for navigation according to claim 1, wherein the coordinate conversion formula enables setting of a parameter for making the joint between adjacent plan perspective views continuous. 3. The map display method for navigation according to claim 1 or 2, wherein after the n plan perspective views are drawn separately, the plan perspective views are copied to a display map. 4. The display map is synthesized after clipping the map information stored in advance in a display frame formed by a boundary line between the plan perspective views. Navigation map display method.