JPH09237035A - Map display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display a bird's-eye view map which allows to easily catch a sense of distance and gives a feeling of attendance. SOLUTION: A grid line information storing memory is previously stored with plural pieces of grid line information which emphasizes the perspective toward the frontal and the right/left directions from the position of the car of interest on the map in the case of the road map display according to the bird's-eye view drawing method, and grid lines are displayed in a manner to overlap the map. Thus, even when a road map is displayed according to the bird's-eye drawing method, a sense of distance can be easily grasped and a road map having high presence feeling can be displayed. By displaying the distances between grid lines, actual distances can be understood more easily from the display screen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a map display device capable of displaying a bird's-eye view map obtained by converting a two-dimensional map into a display format by a bird's-eye view method.

[0002]

2. Description of the Related Art In this specification, a vehicle road map display device will be described as an example. A vehicle map display device is known in which, when a road map is displayed on a display device, the road map around the current location of the vehicle is displayed in a larger scale than at a distance, that is, a so-called bird's-eye view method is used to display the road map ( See, for example, Japanese Patent Laid-Open No. 2-244188). The device disclosed in the above publication places a viewpoint behind the current position of the vehicle and displays a state in which the traveling direction of the vehicle is looked down from this viewpoint on the screen of the display device. Map display by such a bird's eye view method (hereinafter, the map displayed by the bird's eye view method is called a bird's eye view map,
By distinguishing from the plan map displayed as a plan view, the map information around the current location can be enlarged and displayed, and the wide range from the current location to the distant area can be displayed, so the connection status of the road map can be visually grasped. It will be easier. In addition, it is possible to display a realistic road map as if the driver were looking down at the road map.

[0003]

However, when there is originally little road map information to be displayed on the screen, for example, when an area other than the urban area is displayed, is a bird's-eye view map displayed, or the same as in the conventional case? It is difficult to distinguish whether the two-dimensional map is displayed or not, and even if the bird's-eye map is displayed, there is a possibility that the original characteristic of the bird's-eye map cannot be obtained. Further, when the road map is displayed by the bird's-eye view method, the map scale continuously changes from the lower side to the upper side of the screen, which makes it difficult to grasp the perspective and distance of the road map on the screen.

It is an object of the present invention to provide a map display device which gives a bird's-eye view map a greater sense of perspective and distance.

[0005]

According to the map display device of the present invention, a plurality of grid lines for emphasizing the perspective of the bird's-eye view map are superposed on the bird's-eye view map obtained by converting the two-dimensional map into the display form by the bird's-eye view method. In addition to displaying, the distance between a plurality of grid lines is also displayed. In order to create a bird's-eye map, map storage means for storing data relating to a planar map, and map data in a predetermined range is read from the map storage means so that a map by the bird's-eye view method is displayed and converted into a display format by the bird's-eye view method A bird's-eye view data conversion means may be provided. The bird's-eye view map data conversion means converts the plan view map into bird's-eye view map data assuming that a viewpoint is placed above the current position on the plan view map and the plan view is looked down at a predetermined looking-down angle and spread angle from this viewpoint. be able to. The horizontal grid lines are arranged such that the intervals between the grid lines are narrowed from the bottom to the top of the display screen, and the lines from the bottom left and right of the screen to the center of the top of the screen are located from the center of the screen to the left and right. It can be composed of a plurality of oblique grid lines each of which has a narrower interval. Even if the display area changing means for changing the display area of the displayed map is provided, the grid lines on the screen are fixedly displayed regardless of the display area of the displayed map, and the distance between the grid lines displayed on the screen is fixed. Can be changed according to the display area of the bird's-eye view map. When changing the display area by changing the height of the viewpoint, the display area changing means preferably further displays the height of the viewpoint on the bird's-eye view map.

[0006]

1 is a block diagram of an embodiment in which a map display device according to the present invention is applied to a vehicle navigation device. In FIG. 1, reference numeral 1 denotes a current position detection device that detects the current position of the vehicle, for example, a direction sensor that detects the traveling direction of the vehicle, a vehicle speed sensor that detects the vehicle speed, and G
GPS from PS (Global Positioning System) satellite
It is composed of a GPS sensor for detecting signals. 2 is a map storage memory that stores data related to a flat road map,
For example, it consists of a CD-ROM and its reading device.
The road map data stored in the map storage memory 2 mainly includes road data on a planar map, name data, background data, and the like.

Reference numeral 3 is a control circuit for controlling the entire apparatus,
It consists of a microprocessor and its peripheral circuits. Reference numeral 4 denotes an input device having various switches for inputting the destination of the vehicle and the like, and in this example, it is arranged around the display screen. As a remote control method, a command may be sent to the control circuit wirelessly or by wire. Only the details / wide area switches 4a, 4b relevant to the present invention are shown here. The detail / wide area switches 4a and 4b are switches for displaying the display map in detail and displaying a wide area. In this example, it is possible to switch from the most detailed to the most wide area in five steps, and in the case of a bird's-eye view map display, the heights of viewpoints described later are 350 m, 700 m, and 1400 for each step, respectively.
m, 2800m, 5600m.

Reference numeral 5 is a plane map data memory for storing plane road map drawing data for displaying the plane road map viewed from directly above, which is created based on the plane road map data read from the map storage memory 2. To be done. Reference numeral 6 denotes a bird's-eye view map data memory for storing bird's-eye view map drawing data for displaying the plane road map in a bird's-eye view method, which is created based on the plane road map data read from the map storage memory 2. An image memory 7 stores image data to be displayed on a display device 8 described later, and this image data is created from plane map drawing data or bird's-eye view map drawing data. The image data stored in the image memory 7 is appropriately read and displayed on the display device 8. Reference numeral 9 denotes a grid line information storage memory that stores information about the grid lines displayed on the display device 8, and stores information such as display position coordinates of the grid lines on the screen and display line types of the grid lines.

FIG. 2 is a diagram showing an example of grid lines displayed at the same time when a road map is displayed by a bird's eye view method.
The grid lines include horizontal grid lines GH1 to GH8 and oblique grid lines GV11 to GV16. Each grid line is displayed so that the distances on the road map between adjacent grid lines are approximately equal. When the road map is displayed by the bird's-eye view method, the map scale continuously changes from the lower side to the upper side of the screen, so that the interval between the horizontal grid lines GH becomes gradually narrower from the lower side to the upper side of the screen as shown in the figure. Similarly, the diagonal grid lines GV have narrower intervals from the center of the screen to the left and right. Information for displaying the grid lines shown in FIG. 2 is stored in advance in the grid line information storage memory 9 described above.

The grid line display is a fixed grid line so that it does not change regardless of the size of the map display area. Therefore, the distance on the map on each side surrounded by the four grid lines is different depending on the size of the map display area. In the present embodiment, by drawing the sky in the area at the top of the screen to create a sense of depth or distance in the map, and by constantly displaying the distance on the map between the grid lines on the screen, the occupant can see the map display area. It is easy to grasp the size intuitively. A triangular mark TM (referred to as a vehicle position mark) in the screen indicates the current position of the vehicle, and the screen is updated when the vehicle travels a predetermined distance while the vehicle is running. It moves on the screen from the position 2 according to the traveling distance.

FIG. 3 is a flow chart showing the main processing of the control circuit 3, and the operation of the present embodiment will be described below based on this flow chart. The control circuit 3 is
Fig. 3 when the key is operated to the ignition on position
Start the process. In step S1 of FIG. 3, a recommended route and a destination are set. The destination is set by the operator via the input device 4, and the recommended route is automatically set by calculation using, for example, the well-known Dijkstra method. In this case, the current value can use the position detected by the current value detection device 1. Alternatively, recommended route candidates may be stored in advance in a ROM or the like, and any one of them may be selected as the recommended route.

In step S2, the display screen mode is set. The display screen modes set here include a mode for displaying a bird's-eye view map, a mode for displaying a plan map, and a mode for simultaneously displaying a bird's-eye view and a plan map on the same screen. The operation is performed by the operator via the input device 4. When the bird's-eye view map and the plane map are displayed at the same time, one of the road map display areas is displayed in a large size, and the other is displayed in a window in part. Hereinafter, the larger display area is referred to as the base screen, and the window display is referred to as the window screen.

In step S3, the display environment is set.
The display environment set here, for example, the display color of the screen,
There is a choice between night mode and daytime mode. The operator selects these display environments via the input device 4. In step S4, the current position of the vehicle is detected based on the signal from the current position detection device 1. In step S5, as shown in FIGS.
A map is displayed by performing a map display process showing details. Details of the map display process will be described later.

In step S6, the current position is detected in the same manner as in step S4. In step S7, it is determined whether or not to update the road map on the screen, that is, whether or not to rewrite the road map. Here, for example, based on the detected current position, when the vehicle has traveled a predetermined distance or more since the last map update, when the operator operates the detail switch 4a and the enlargement switch 4b, or when the operator operates the input device. When scrolling is instructed via 4, it is determined that the road map displayed on the screen is to be updated.

If the determination in step S7 is affirmative, the process returns to step S5, and if the determination is negative, the process proceeds to step S8. In step S8, it is determined whether to continue the main process of FIG. For example, if a power switch (not shown) is turned off or a switch for stopping the process is operated, the determination in step S8 is denied and the main process of FIG. 3 is ended.

If the determination in step S8 is affirmative, the process proceeds to step S9, the display of the attached information is updated, and then the process returns to step S4. Here, the attached information includes, for example, a north direction mark and a vehicle mark.

4 to 7 are flow charts showing the details of the map display processing in step S5 of FIG. In step S101 of FIG. 4, it is determined whether the road map displayed on the base screen is a bird's-eye view map. Here, the determination is made based on the display screen mode set in step S2 of FIG. If the determination in step S101 is positive, step S
In step 102, the bird's-eye view map display process shown in detail in FIG. 5 is performed, and the bird's-eye view map is displayed in the base screen display area on the screen.

On the other hand, if the determination in step S101 is negative, the process proceeds to step S103, in which the planar map display processing shown in detail in FIG. 7 is performed, and the planar map is displayed in the base screen display area on the screen. When the process of step S102 or S103 ends, the process proceeds to step S104 to determine whether to display the window screen. Here, the determination is made based on the display screen mode set in step S2 of FIG.

If the determination in step S104 is affirmative, the flow advances to step S105 to determine whether the road map displayed on the window screen is a bird's-eye view map. This judgment is also shown in FIG.
The determination is made based on the display screen mode set in step S2. If the determination in step S105 is affirmative, the process proceeds to step S106 to perform the bird's-eye view map display process shown in detail in FIGS. 5 and 6 to display the bird's-eye view map in the window screen. On the other hand, if the determination in step S105 is negative, the process proceeds to step S107 to perform a planar map display process, the details of which are shown in FIG. 7, to display a planar map in the window screen.

When the process of step S106 or S107 is completed, or when the determination of step S104 is negative, the process proceeds to step S108, and the auxiliary information such as the vehicle position mark is displayed on both the base screen and the window screen. And return.

5 and 6 show step S10 of FIG.
It is a flowchart which shows the detail of the bird's-eye view map display process of 2. Step S200 in FIG. 5 is a process for changing the size of the display map area by operating the detail switch 4a or the wide area switch 4b, and details thereof are shown in FIG.

In FIG. 6, when the operation of the detail switch 4a or the wide area switch 4b is determined in step S2001, the process proceeds to step S2002. Step S2002
Then, it is determined whether the current detailed / wide area selection state is the most detailed or the most wide area. If the result is affirmative, the processing is terminated without doing anything, and if the result is negative, the process proceeds to step S2003. Step S20
In 03, the distance between grid lines is calculated from the states of the detail switch 4a and the wide area switch 4b. The calculation of the distance between grid lines can be performed as follows.

Detailed switch 4a or wide area switch 4
When displaying the map in the display area (scale ratio in a plan map) selected in b by the bird's-eye view method, the bird's-eye view image data is created by changing the viewpoint height set in five stages as described above. Therefore, the viewpoint height corresponding to the selected display area is obtained, and the grid line distance previously stored in the table according to the viewpoint height is read based on the obtained viewpoint height. Viewpoint height 350m, 700m, 1400m, 2
For 800m and 5600m, the distances between grid lines are 500m, 1km, 2km, 4km and 8k, respectively.
m. In step S2004, as shown in FIG. 12, the selected detail / wide area selection state is displayed in an overlapping manner on the bird's-eye view screen displayed in the current detail / enlargement selection state. In step S2005, the map data having the viewpoint height according to the selected detail / wide area selection state is selected, and the process ends. That is, the process proceeds to step S201 in FIG.

FIG. 12 shows an example in which the detailed / wide area selection state is overlaid and displayed on the bird's-eye view map screen. This example shows a state in which the one-stage wide area side is selected when the bird's-eye view map is displayed in the most detailed state, and the current detailed / wide area selected state is indicated by the reference numeral 41 in the first area D1. Is displayed. The viewpoint height is displayed in the second area D2, the grid line distance “1 km” in the detailed / wide area selection state of reference numeral 41 is displayed in the third area D3, and the current area is displayed in the fourth area D4. Distance between grid lines in the most detailed state "500m"
Is displayed.

In step S201, a display direction angle when a map is displayed by the bird's eye view method is calculated. FIG. 8 is a diagram illustrating a method of calculating the display direction angle α. The XY axes shown in the figure represent the road map plane, the origin O is the starting point of the vehicle, and the coordinates G
(X0, Y0) is the current position of the vehicle, and coordinates P1 (X1, Y0)
1) shows the destinations respectively. As shown in the figure, the display direction angle α is the angle between the X-axis and the line segment (the dotted line in the figure) connecting the current position G and the destination P1 and is represented by the equation (1).

Tan α = {(Y1−Y0) / (X1−X0)} (1) In step S201, the display direction angle α is obtained based on the equation (1). In addition, in FIG. 8, θ indicates an angle of ½ of a spread angle described later, and regions surrounded by A, B, C, and D respectively indicate regions on the map displayed by the bird's-eye view method.

In step S202, step S in FIG.
The road map data around the current position is read from the map storage memory 2 based on the current position detected in step S4 and S6 and the display direction angle α calculated in step S201. For example, the road map data of several 10 km square including the current location is read. The read range increases as the viewpoint height increases.

In step S203, step S202
Data to be used when displaying the bird's-eye map is selected from the road map data read in step 3, and the selected data is stored in the bird's-eye map data memory 6. Here, the display device 8
In order to reduce the amount of data of road map information displayed in
Only data whose data type satisfies a predetermined condition is extracted and stored in the bird's-eye view map data memory 6. Step S20
In step 4, the road map data selected in step S203 is converted into bird's-eye view map data.

FIG. 9 is a diagram for explaining the conversion to bird's-eye view map data. The road map is the XY plane, the viewpoint M is placed on the Z axis orthogonal to the XY plane, and the angle of looking down from the viewpoint M is φ. Here is an example: The rectangle abcd shown in the drawing shows the display range of the display device 6 as enlargedly displayed in FIG. 10, and the trapezoid ABCD of FIG. 9 shows the road map range displayed on the display device 8.

In order to convert the road map data into the bird's-eye view map data, first, from the height Z of the viewpoint M and the viewpoint M so that all the road map data in the trapezoidal area ABCD shown in the figure can be displayed on the display device 8. After determining the view-down angle φ and the spread angle 2θ from the viewpoint, the bird's-eye view map data projected on the rectangular area abcd in FIG. 10 is created using these parameters. At this time, the gaze angle φ is set so that the vicinity of the center line connecting the middle points of the upper side and the lower side of the display screen of the display device 8 is about 1.2 km forward.

Returning to FIG. 5, in step S205, the bird's-eye view map data converted in step S204 is converted into final map image data to be displayed on the display device 8. In step S206, the grid line information for the bird's-eye view map shown in FIG. 3 is read from the grid line information storage memory 9, and the distance between grid lines calculated in step S2003 is combined with the map image data together with the mark, and then the image memory is displayed. Store in 7 and return.

FIG. 7 is a flow chart showing details of the plane map display processing of step S103 of FIG. In step S301 of FIG. 7, a road map around the current position of the vehicle is read from the map storage memory 2. In step S302,
From the road map data read in step S301, the data used for displaying the plane map is selected, the selected data is stored in the plane map data memory 5 as the plane map data, and the process returns. Here, FIG.
Similar to step S203, the high priority data or the like is selected. In step S303, the plan map data stored in the plan map data memory 5 is converted into map image data and stored in the image memory 7, and the process returns.

A case where the screen on which the bird's-eye view map is displayed in the most detailed state is shifted to the one-step wide area will be described with reference to FIGS. 11 to 13. FIG. 11 is a screen display in the most detailed state (state in which the viewpoint height is the lowest). In the area D5, "500 m", which is the distance between the grid lines in the most detailed state, is displayed together with the mark GM. In this state, if the wide area switch 4b is operated once to move to the wide area side by one step (the viewpoint height is increased by one step), first, without changing the map itself,
As shown in FIG. 12, detailed / enlarged selection state information is displayed at the bottom of the screen. The area D1 indicates a state shifted to the one-step wide area by the reference numeral 41. The area D2 is the viewpoint height "700 m", and the area D3 is the distance between grid lines corresponding to the viewpoint height "700 m". Along with the mark, a certain "1 km" is the distance between grid lines corresponding to the viewpoint height before changing the detail / enlargement state in the area D4, "50".
"0 m" is displayed together with the mark (step S2004). Thereafter, bird's-eye view map image data is created based on the selected detail / wide area state, that is, the height of the viewpoint, stored in the memory 7 and the screen is updated, and the area shown in FIG. 13 is superimposed on the image. Distance between grid lines according to the viewpoint height after changing to D5 "1k
m ”is displayed.

In the embodiment described above, a plurality of grid lines as shown in FIG. 2 are displayed in an overlapping manner on a road map displayed by the bird's eye view method, and a numerical value according to the distance between the grid lines is displayed. I made it visible.
Therefore, when the map is displayed by the bird's-eye view method, the map can be displayed with a sense of depth or perspective, and by displaying the distance between grid lines, it becomes easier to grasp the actual distance on the bird's-eye view map. Also, since the display position of the grid line is always fixed, the grid line is rewritten when the road map on the screen is scrolled or when the map is updated by changing the display area by changing the viewpoint height. There is no need, and grid lines can be displayed without affecting the screen rewriting speed.

Further, when the detail / wide area is selected, that is, when the viewpoint height is changed, the changed viewpoint height and the distance between grid lines before and after the change are displayed before updating the map screen as shown in FIG. As a result, the operator can easily understand the state before and after the screen change.

In each of the above embodiments, a plurality of display line types for each grid line may be provided and the grid lines may be displayed using a plurality of different display line types. For example, thin line grid lines may be displayed in units of several hundred meters, and thick line grid lines may be displayed in units of several kilometers. Further, when displaying the bird's-eye view, if the grid line on the lower side of the screen is displayed thick and the grid line on the upper side is displayed thin, a more realistic road map can be displayed. Further, for example, a grid line may be displayed based on the current position of the vehicle, depending on the distance from the current position. In this way, it becomes easier to understand the distance from the current location.

The map display device according to the present invention is not limited to a vehicle. Also, not limited to road maps, mountain maps,
It is effective when displaying various maps such as river maps and nautical charts by the bird's eye view method. Further, the grid lines of the embodiment are not limited as long as the perspective and the depth are emphasized.
Furthermore, the plane map data is converted into the bird's-eye view map data to display the bird's-eye view map, but the bird's-eye view map data may be stored in advance in a memory such as a CD-ROM and the conversion process may be omitted. In the above, the viewpoint height is changed to make the map display area detailed or wide, but the display area may be increased or decreased by other methods.

In the embodiment configured as described above, the map storage memory 2 serves as the map storage means, the control circuit 3 particularly step S204 in FIG. 5 serves as the bird's-eye view map data conversion means,
Step S200 in FIG. 6 corresponds to the display area changing means.

[0038]

As described in detail above, according to the present invention, the grid lines for emphasizing the perspective of the map according to the bird's-eye view method are displayed so as to be superimposed on the bird's-eye view map. It is possible to make the display form full of realism. In addition, by displaying the distance between grid lines, it is possible to make it easier to grasp the actual distance on the bird's-eye view map. According to the invention of claim 4, the display interval of the grid lines is gradually narrowed from the central portion of the display screen to the left side and the right side, and the display interval of the grid lines is gradually reduced from the lower side to the upper side of the display screen. Since it is narrow, a more realistic bird's-eye view map can be displayed. According to the invention of claim 5, when the map display area can be changed, the grid lines are fixedly displayed regardless of the map range displayed on the screen to improve the image processing speed. However, since the actual distance between the fixed grid lines is displayed numerically, there is no fear that the distance will be difficult to grasp. According to the sixth aspect of the invention, when the display area is changed by the viewpoint height, the viewpoint height is also displayed so that the screen becomes easier to see.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a map display device according to the present invention.

FIG. 2 is a diagram showing a display example of grid lines in FIG.

FIG. 3 is a flowchart showing main processing.

FIG. 4 is a flowchart showing map display processing.

FIG. 5 is a flowchart showing a bird's-eye view map display process.

FIG. 6 is a flowchart showing detailed / wide area selection processing.

FIG. 7 is a flowchart showing a planar map display process.

FIG. 8 is a diagram illustrating a method of calculating a display direction angle of a bird's-eye view map.

FIG. 9 is a diagram illustrating conversion into bird's-eye view map data.

10 is an enlarged view of the rectangular area abcd shown in FIG.

FIG. 11 is a diagram showing a screen display example when a bird's-eye view map is displayed.

FIG. 12 is a diagram showing a screen display example when a bird's-eye view map is displayed.

FIG. 13 is a diagram showing a screen display example when a bird's-eye view map is displayed.

[Explanation of symbols]

 1 Current Location Detection Device 2 Map Storage Memory 3 Control Circuit 4 Input Device 4a Detailed Switch 4b Wide Area Switch 5 Plane Map Data Memory 6 Bird's Eye Map Data Memory 7 Image Memory 8 Display Device 9 Grid Line Information Storage Memory

Claims (6)

[Claims] 1. A bird's-eye view map obtained by converting a two-dimensional map into a display format by a bird's-eye view method, a plurality of grid lines that emphasize the perspective of the bird's-eye view map, and a distance between the plurality of grid lines are displayed in an overlapping manner. A map display device. 2. The map display device according to claim 1, wherein map storage means for storing data relating to the planar map, and map data within a predetermined range from the map storage means so that a map by a bird's eye view method is displayed. A map display device comprising a bird's-eye view map data conversion means for reading out and converting into a display format by a bird's-eye view method. 3. The map display device according to claim 2, wherein the bird's-eye view map data conversion means places a viewpoint in the sky above the current position on the planar map, and at a predetermined look-down angle and spread angle from this viewpoint. A map display device for converting to bird's-eye view map data when looking down on the planar map. 4. The map display device according to claim 1, wherein the plurality of grid lines have a plurality of horizontal grid lines whose intervals are narrowed from the lower side to the upper side of the display screen. And a plurality of diagonal grid lines each of which is directed from the lower left and right sides of the screen to the center of the upper side of the screen, and the distance between the center of the screen and the left and right sides is narrowed. apparatus. 5. The map display device according to claim 1, further comprising display area changing means for changing a display area of a displayed map, and grid lines on the screen are displayed. A map display device, which is fixedly displayed regardless of a display area of a map, and a distance between the grid lines displayed on the screen is changed according to a display area of the bird's-eye view map. 6. The map display device according to claim 5, wherein the display area changing unit changes the display area by changing the height of the viewpoint, and further displays the height of the viewpoint on the bird's-eye view map. A map display device characterized by: