JP3662998B2 - Map display device for moving objects - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a map display device for a moving body that can display a bird's-eye view map obtained by converting a planar map into a display format based on a bird's-eye view.
[0002]
[Prior art]
In this specification, a vehicle map display device will be described as an example. When displaying a road map on a display device, there is known a vehicle map display device that displays a road map in a so-called bird's-eye view that displays a road map around the current location of the vehicle in an enlarged manner from a distance. For example, see JP-A-2-244188). The apparatus disclosed in the above publication places a viewpoint behind the current location of the vehicle, and displays on the screen of the display device a state in which the traveling direction of the vehicle is looked down from this viewpoint. When map display based on such a bird's eye view method (hereinafter, a map displayed by the bird's eye view method is called a bird's eye view map and distinguished from a plane map displayed as a plan view), the map information around the current location is enlarged and displayed. As well as being able to display a wide range from the present location to a distant place, it becomes easier to visually grasp the connection status of the road map. In addition, a realistic road map can be displayed as if the driver is looking down at the road map.
[0003]
In a map display device that displays such a bird's-eye view map, the scale of the road map according to the bird's-eye view method changes continuously from the lower side to the upper side of the screen. In addition, the current position mark of the vehicle is displayed at a predetermined size at a predetermined position on the screen.
[0004]
[Problems to be solved by the invention]
When scrolling the screen with a conventionally known joystick, if the vehicle position mark is moved with the scroll of the road map so that the vehicle position mark is always displayed over the current location, the scale of the road map will change. Nevertheless, since the size of the vehicle position mark does not change, the vehicle position mark is displayed larger or smaller than the surrounding road map.
[0005]
An object of the present invention is to provide a map display device for a moving body that changes the size of a current position mark such as a vehicle position mark according to the scale of a display map when scrolling a bird's eye view map. is there.
[0006]
[Means for Solving the Problems]
The present invention is applied to a map display apparatus for a moving body that displays a bird's-eye view map obtained by converting a planar map into a display format based on a bird's-eye view, and displays a current position mark superimposed on the current location of the moving body on the bird's-eye view map. .
(1) Then, command means for instructing to scroll the bird's eye view map displayed on the screen in the vertical direction of the screen, area dividing means for dividing the screen into a plurality of areas in the vertical direction, and a plurality of different sizes Mark storage means for storing the current position mark, mark position determination means for determining which of the plurality of areas divided by the area dividing means in the map scrolled by the command means, mark position Depending on which area the current position is determined by the determination means, one of the current position marks of different sizes stored by the mark storage means becomes a current position mark that is smaller in the upper area of the screen. Mark selection means for selecting, and mark display control means for displaying the current position mark selected by the mark selection means . This achieves the above object.
(2) In order to display a bird's-eye view map, a map storage means for storing data relating to a planar map, and a display format based on a bird's-eye view method by reading out a predetermined range of map data from the map storage means so that a map by the bird's-eye view method is displayed In this case, when there is no scroll command, a viewpoint is placed above the current location on the plane map, and a predetermined look-down angle and spread from this viewpoint. Convert to bird's-eye view map data when looking down at a flat map at an angle, and when there is a scroll command, change the position of the viewpoint from the current location to the front or back according to the command and convert it to bird's-eye view map data be able to.
(3) In the case where an area for displaying the sky is formed at the top of the screen, it is possible to provide prohibiting means for prohibiting the display of the current position mark in the empty area.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram of an embodiment in which a map display apparatus for a moving body according to the present invention is applied to a vehicle navigation apparatus. In FIG. 1, reference numeral 1 denotes a current position detection device that detects the current position of a vehicle. For example, a direction sensor that detects the traveling direction of a vehicle, a vehicle speed sensor that detects a vehicle speed, and a GPS signal from a GPS (Global Positioning System) satellite. It consists of a GPS sensor. Reference numeral 2 denotes a map storage memory for storing data relating to a planar road map, which includes, for example, a CD-ROM and a reading device thereof. The road map data stored in the map storage memory 2 mainly includes road data, name data, background data, etc. on a planar map.
[0008]
A control circuit 3 controls the entire apparatus and includes 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 is arranged around the display screen in this example. As a remote control method, a command may be sent to the control circuit wirelessly or wiredly. The detail / wide area switches 4a and 4b are switches for displaying the display map in detail or displaying the wide area. In this example, it is possible to switch from the highest level to the widest range in five levels. In the case of bird's-eye view map display, the height of the viewpoint described later is set to 350 m, 700 m, 1400 m, 2800 m, and 5600 m for each level. . The scroll switch 4c is for scrolling the display screen up and down, and various types of switches can be used, and a so-called joystick may be used. It is also possible to provide a scroll switch that changes the look-down direction around the current location. In this case, the screen can be scrolled not only in the vertical direction but also in the rotational direction.
[0009]
Reference numeral 5 denotes a plane map data memory for storing plane road map drawing data for displaying the plane road map when viewed from directly above, and is created based on the plane road map data read from the map storage memory 2. Reference numeral 6 denotes a bird's-eye map data memory for storing bird's-eye map drawing data for displaying a planar road map in a bird's-eye view, and is created based on the planar road map data read from the map storage memory 2. Reference numeral 7 denotes an image memory for storing image data to be displayed on the display monitor 8 to be described later. This image data is created from plane map drawing data or bird's-eye map drawing data. The image data stored in the image memory 7 is appropriately read and displayed on the display monitor 8. Reference numeral 9 denotes a storage memory for storing the own vehicle position mark displayed on the display monitor 8, and here, description will be made assuming that two own large and small own vehicle position marks are stored.
[0010]
FIG. 2 is a diagram showing an image that is superimposed when a road map is displayed in a bird's eye view, and TM is a vehicle position mark displayed on the current ground of the vehicle. During traveling, the map is not updated until the vehicle has traveled a predetermined distance, and the vehicle moves upward from the reference position in FIG. When the vehicle travels a predetermined distance or more, the screen is updated, and the vehicle position mark TM returns to the reference position in FIG. The code TMa will be described later.
[0011]
As shown in FIG. 2, in this embodiment, the display range of the display monitor 8 is divided into four areas. If the X-axis direction of the display screen of the display monitor 8 is, for example, 500 dots, the Y-axis direction is 400 dots, and the lower left corner of the screen is the origin of coordinates, the first area of the four areas is the coordinate in the Y-axis direction. Is in the range of 0 to 200 dots, the second area is in the range of 200 to 300 dots in the Y-axis direction, the third area is in the range of 300 to 350 dots in the Y-axis direction, and the fourth area is in the Y-axis direction. The coordinates are in the range of 350 to 400 dots. The first area to the third area are road map display areas, and the fourth area is an empty display area.
[0012]
According to the method for creating bird's-eye view map data, which will be described later, when the viewpoint height is fixed, the bird's-eye view map is displayed in the first area in the narrowest area around the current location at the most detailed scale, and in the third area. The bird's-eye view map is displayed at the coarsest and small scale ratio in a wide area at a point far from the current location, and the bird's-eye view map is displayed at an intermediate scale area in the second area. As can be understood from the description of FIG. 3 described later, the scale ratio in the first region to the third region gradually decreases as the distance from the current location increases (see FIG. 12).
[0013]
Note that GH is a horizontal grid line, and GV is a diagonal grid line, and expresses a sense of perspective and depth on a bird's-eye view map. Each grid line is displayed so that the distance on the road map between adjacent grid lines is approximately equal. When a road map is displayed in a bird's eye view, the map scale continuously changes from the lower side of the screen to the upper side. Therefore, as shown in the figure, the interval between the horizontal grid lines GH gradually decreases from the lower side of the screen to the upper side. Similarly, the diagonal grid lines GV have narrower intervals from the center of the screen to the left and right.
[0014]
FIG. 3 is a diagram for explaining bird's-eye view map data for displaying a bird's-eye view map on the monitor 8. The road map is the XY plane, the viewpoint M is placed on the Z-axis orthogonal to the XY plane, and the looking-down angle from the viewpoint M is shown. An example in which is set to φ is shown. The illustrated rectangle abcd indicates the display range of the display monitor 8 so as to be enlarged and displayed in FIG. 4, and the trapezoid ABCD in FIG. 3 indicates the road map range displayed on the display monitor 8.
[0015]
In order to convert road map data into bird's-eye view map data, first, the height Z of the viewpoint M and the angle from 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 monitor 8. After determining φ and the spread angle 2θ from the viewpoint, the bird's-eye view map data projected onto the rectangular area abcd of FIG. 4 is created using these parameters.
At this time, the looking-down angle φ is set so that the vicinity of the center line connecting the midpoints of the upper and lower sides of the display screen of the display monitor 8 is about 1.2 km ahead of the host vehicle.
Note that the Y coordinate of the viewpoint is set at a point that is a predetermined distance behind the current location of the vehicle, and both the screen scroll by the scroll switch 4c and the screen scroll for each predetermined travel distance change the Y coordinate position of this viewpoint. Create bird's-eye view map data. Further, the map display direction is the own vehicle traveling direction.
[0016]
FIG. 5 is a diagram for explaining a method of calculating the angle α representing the display direction. The XY axes shown in the figure indicate the road map plane, the origin O indicates the starting point of the vehicle, the coordinates G (X0, Y0) indicate the current location of the vehicle, and the coordinates P1 (X1, Y1) indicate the destination. As shown in the figure, the display direction angle α is an angle between a line segment (the dotted line in the figure) connecting the current location G and the destination P1 and the X axis, and is represented by equation (1).
[Expression 1]
tan α = {(Y1-Y0) / (X1-X0)} (1)
In FIG. 5, θ represents a half angle of the above-described spread angle, and regions surrounded by A, B, C, and D represent regions on a map that are displayed in a bird's eye view.
[0017]
FIG. 6 is a flowchart showing the main processing of the control circuit 3, and the operation of the present embodiment will be described below based on this flowchart. The control circuit 3 starts the process of FIG. 6 when the key is operated to the ignition on position.
In step S1 of FIG. 6, 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, a well-known Dijkstra method. In this case, the position detected by the current position detection device 1 can be used as the current position. Alternatively, recommended route candidates may be stored in advance in a ROM or the like, and one of them may be selected as the recommended route.
[0018]
In step S2, a display screen mode is set. The display screen mode set here includes a mode for displaying a bird's-eye view map and a mode for displaying a planar map. These modes are selected by the operator via the input device 4. In step S3, a display environment is set. The display environment set here includes, for example, the display color of the screen and the selection of the night mode and the daytime mode. The display environment is selected by the operator via the input device 4. In step S4, the current location of the vehicle is detected based on the signal from the current location detection device 1. In step S5, map display processing shown in detail in FIGS. 7 and 8 is performed to display a map. Details of the map display process will be described later.
[0019]
In step S6, the current location is detected in the same manner as in step S4. In step S7, it is determined whether to update the road map on the screen, that is, whether to rewrite the road map. Here, based on the detected current position, it is determined that the road map displayed on the screen is to be updated when the vehicle has traveled more than a predetermined distance from the previous map update time. This screen update is called scrolling by travel distance, and is distinguished from screen scrolling by the scroll switch 4c.
[0020]
If the determination in step S7 is affirmed, 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 or not to continue the main process of FIG. For example, when a power switch (not shown) is turned off or when a switch for stopping the process is operated, the determination in step S8 is denied and the main process in FIG. 6 is terminated.
[0021]
If the determination in step S8 is affirmed, the process proceeds to step S9, the display of the vehicle position mark is updated, and then the process returns to step S4. The vehicle position mark is displayed over the current location on the map, but the vehicle position mark is moved on the map according to the travel distance until the map is scrolled by a predetermined distance in step S7. The display of the position mark is updated.
[0022]
FIG. 7 is a flowchart showing details of the map display process in step S5 of FIG. In step S201, the display direction angle α when displaying a map in the bird's eye view is calculated. In step S202, road map data around the current location is read from the map storage memory 2 based on the current location detected in steps S4 and S6 in FIG. 6 and the display direction angle α calculated in step S201. For example, road map data of several 10 km square including the current location is read.
[0023]
In step S203, data used when displaying the bird's-eye view map is selected from the road map data read in step S202, and the selected data is stored in the bird's-eye view map data memory 6. Here, in order to reduce the data amount of the road map information displayed on the display monitor 8, only the data whose data type satisfies the predetermined condition is extracted and stored in the bird's eye view map data memory 6. In step S204, the road map data selected in step S203 is converted into bird's eye view map data. The outline of data conversion is as described above. 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 monitor 8. In step S 206, a large vehicle position mark is read from the vehicle position mark storage memory 9, the vehicle position mark is combined with the map image data and stored in the image memory 7, and the image is displayed on the display memory 8.
[0024]
FIG. 8 is a flowchart of a program that is interrupted when the scroll switch 4c is operated. In step S301, the Y coordinate on the map relating to the current vehicle position mark is read and stored. In step S302, the scroll direction is determined from the operation state of the scroll switch 4c. When the scroll switch 4c is operated in order to confirm the map behind the vehicle position, the process proceeds to step S303, and the position of the viewpoint position on the map is moved backward by a predetermined distance from the current location. The trapezoidal area ABCD described in (1) is set. In step S304, a bird's eye map drawing range including the trapezoidal area ABCD is set, and road map data in the range is read from the map storage memory 2.
[0025]
In step S305, as in step S203, the data used when displaying the bird's-eye view map is selected from the road map data read in step S304, and the selected data is stored in the bird's-eye view map data memory 6. In step S306, as in step S204, the road map data stored in step S305 is converted into bird's-eye view map data. In step S307, similarly to step S205, the bird's-eye view map data converted in step S306 is converted into final map image data to be displayed on the display monitor 8.
[0026]
In step S308, based on the map image data converted in step S309, the current location Y coordinate at the start of scrolling stored in step S301 is converted into a Y coordinate on the screen. In step S309, it is determined whether the current location is located in the third area of the screen based on the converted Y coordinate on the screen. If a negative determination is made in step S309, a large vehicle position mark is selected from the vehicle position mark storage memory 9 and converted into image data in step S310. If step S309 is positive, the process proceeds to step S315, and it is determined whether the Y coordinate on the screen has reached the upper end of the third region. Here, the upper end of the third area is determined so that the vehicle position mark does not enter the fourth area even if part of the vehicle position mark.
[0027]
If step S315 is negative, in step S311, a small vehicle position mark is selected from the vehicle position mark storage memory 9 and converted to image data. In step S312, the vehicle position mark is combined with the map image data and stored in the image memory 7, and the image is displayed on the display monitor 8. If step S315 is affirmed, the vehicle position mark is deleted in step S316, and the process proceeds to step S312. In step S314, it is determined whether or not the scroll switch 4c is operated. If the switch is on, the process returns to step S301 to continue the above-described processing, and if it is off, the interrupt processing is terminated.
[0028]
Note that if it is determined in step S302 that it is instructed to confirm the map ahead of the vehicle position by operating the scroll switch 4c, the screen is scrolled so as to flow downward as described above. In this case, the bird's-eye view map data is created by moving the viewpoint position forward. Therefore, it is possible to display a road map ahead of the farther vehicle, and the own vehicle position mark moves downward in the screen.
[0029]
When the scroll switch 4c is operated to display a map behind the vehicle by the above processing, the vehicle position mark TM moves from the position of FIG. . When the current location reaches the third region, as shown in FIG. 9, a small vehicle position mark TMb is displayed over the current location. Furthermore, since the vehicle position mark is erased when the current position reaches the upper end of the third region so that the vehicle position mark TMb does not enter the fourth region, that is, the sky, the vehicle position mark is empty. An unsightly display that rises can be prevented.
[0030]
In the above description, the map data in the trapezoidal area ABCD in FIG. 3 is displayed as a bird's eye map in the first to third areas of the screen, and the sky is displayed in the fourth area. Here, if the empty drawing of the fourth area is superimposed on the uppermost layer of the display screen, the vehicle position mark is not displayed in the fourth area. However, since the empty image data is not drawn on top of the top for the following reason, if the current position reaches the fourth area as described above, the vehicle position mark must be deleted without processing. Will rise in the sky. Hereinafter, this point will be described.
[0031]
When the map data of the trapezoidal area ABCD in FIG. 3 is read, a rectangular area A′B′C′D ′ inscribed in the trapezoidal area ABCD is set and clipped as shown in FIG. 10A, and the rectangular area A′B is clipped. 'C'D' data is read and converted into bird's-eye view map data as shown in FIG. This is to improve the processing speed. Therefore, the area CC′D includes map data of a point farther than the trapezoidal area ABCD in the direction of looking down. Therefore, in order to display the name of the prefecture in the area CC′D in the empty area, the name data is drawn on the sky. Also, the vehicle position mark is drawn on a layer above the empty drawing layer. For this reason, when the current location of the vehicle is detected in the CC′D area outside the trapezoidal area ABCD, the vehicle position mark is displayed in the fourth area as in the normal case. Therefore, as described above, the vehicle position mark is not displayed when the current location is in the fourth area.
[0032]
In the above description, the large and small vehicle position marks are stored as graphic codes in the storage memory 2 and appropriately selected. Next, the vehicle position marks are stored as vector graphic information, and the vehicle position marks are stored in accordance with the map scale. A case where the size is changed will be described.
[0033]
As shown in FIG. 11, when the current position reference position of the normal display screen is represented by P, the size of the vehicle position mark at this position P is set to an enlargement factor 1. As the current location is located above the point P, the enlargement rate is reduced to reduce the mark according to the map reduction rate, and as the current location is located below the point P, the enlargement rate is increased to reduce the mark to the map. Increase according to the rate. The enlargement ratio may be limited to 1.
[0034]
FIG. 12 shows the relationship between the Y coordinate (area) on the screen and the mark enlargement ratio. The enlargement ratio is 1 at the point P, and the enlargement ratio is gradually reduced from 1 to 1/3 until the point P reaches the third area. The mark size is set so that it does not become 1/3 or less of the P point after reaching the third region. Further, the enlargement ratio is set so as to gradually increase from 1 behind the vehicle position behind the point P.
[0035]
Such display processing of the vehicle position mark is shown in FIG. Step S315 is executed after step S308 in FIG. 8 to determine whether or not the current location on the screen has reached the upper end of the third area. If the result is negative, the mark enlargement ratio is obtained based on the relationship in FIG. A process for setting the size of the figure may be executed, and then the process may proceed to step S312. Further, when the current location reaches near the upper end of the third area, step S315 is affirmed and the process proceeds to step S318, the vector figure is erased with an enlargement rate of 0, and the vehicle position mark is displayed in the fourth area where the sky is displayed. Do not be.
[0036]
According to such an embodiment, the vehicle position mark has a size corresponding to the scale ratio of the bird's-eye view map, the vehicle position mark having a size matching the display of the bird's-eye view map can be displayed, and a screen that is easier to see Become. In this case, since the size of the vehicle position mark is not changed by the scale ratio in the third region, it is possible to prevent the mark from becoming too small to check the vehicle position.
[0037]
The map display apparatus for moving bodies according to the present invention is not limited to vehicles, and can be used for various map displays for moving bodies. Further, the present invention is not limited to a road map, and various maps such as a mountain map, a river map, and a nautical chart are displayed by a bird's eye view method, and is effective when displaying the current position of a moving place on the map. Further, although the vehicle position mark is a black arrow, it is not limited to the embodiment as long as it is a mark indicating the vehicle position. Furthermore, the planar map data is converted into the bird's-eye view map data and the bird's-eye view map is displayed. However, the bird's-eye view map data may be stored in a memory such as a CD-ROM in advance and the conversion process may be omitted. Furthermore, the present invention is also effective when there is no empty display area at the top of the screen.
[0038]
In the embodiment configured as described above, the scroll switch 4c is used as the command means, steps S309, S310, and S311 in FIG. 8 are used as the mark display control means, the map storage memory 2 is used as the map storage means, and the process shown in FIG. Step S306 corresponds to the bird's eye view map data conversion means, and steps S315 and S316 in FIG. 8 correspond to the prohibition means.
[0039]
【The invention's effect】
As described above in detail, according to the present invention, when the scroll command means a map by the bird's-eye view method, also mark indicating the current position of the moving body along with the movement of the map Before moving on the screen. At this time, it is determined whether the current position is located in a plurality of areas obtained by dividing the screen in the vertical direction, and according to the determination result, any of the stored current position marks having different sizes is Since the current position mark is selected and displayed so as to be smaller in the area , the size of the mark changes according to the size of the map, and the mark can be displayed on the screen without any sense of incongruity. Furthermore, the current position mark can be displayed in a simple configuration in correspondence with the scale of the map.
When an area for displaying the sky is set on the upper side of the screen, the current position mark is not displayed in the empty area, so that the display in which the mark goes up in the sky can be prevented.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a map display device for a moving body according to the present invention.
FIG. 2 is a view showing a display example of a vehicle position mark and a grid line.
FIG. 3 is a diagram for explaining conversion into bird's-eye view map data;
4 is an enlarged view of a rectangular area abcd shown in FIG.
FIG. 5 is a diagram for explaining a calculation method of a display direction angle of a bird's eye view map;
FIG. 6 is a flowchart showing main processing.
FIG. 7 is a flowchart showing map display processing.
FIG. 8 is a flowchart showing scroll processing.
FIG. 9 is a diagram for explaining that the size of the vehicle position mark changes in two stages.
FIG. 10 is a diagram illustrating clipping of map data.
FIG. 11 is a diagram for explaining that the size of the vehicle position mark changes continuously.
FIG. 12 is a graph showing the relationship between the display area of the screen and the mark enlargement ratio.
FIG. 13 is a flowchart illustrating a mark display processing procedure according to another embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Present location detection device 2 Map memory 3 Control circuit 4 Input device 4a Detailed switch 4b Wide area switch 4c Scroll switch 5 Plane map data memory 6 Bird's eye view map data memory 7 Image memory 8 Display device 9 Own vehicle position mark storage memory

Claims (3)

In a map display device for a moving body that displays a bird's-eye view map obtained by converting a planar map into a display format based on a bird's-eye view and displays a current position mark superimposed on the current position of the moving body on the bird's-eye view map.
Command means for commanding to scroll the bird's eye view map displayed on the screen at least in the vertical direction of the screen;
Area dividing means for dividing the screen into a plurality of areas in the vertical direction;
Mark storage means for storing a plurality of current position marks of different sizes;
Mark position determination means for determining which of the plurality of areas the current position is divided by the area dividing means on the map scrolled by the command means;
Depending on which area the current position is determined by the mark position determination means, one of the current position marks stored in the mark storage means with different sizes is displayed in a smaller current position mark in the upper area of the screen. Mark selecting means for selecting so that
A map display device for a moving body, comprising: mark display control means for displaying a current position mark selected by the mark selection means . In the map display apparatus for mobile bodies described in Claim 1 ,
Map storage means for storing data relating to the planar map;
A bird's-eye view map data conversion means for reading out a predetermined range of map data from the map storage means so as to display a bird's-eye view map, and converting the map data into a display format using the bird's-eye view method;
When the bird's-eye view map data conversion means does not have the scroll command, the bird's-eye view map data conversion means places a viewpoint in the sky around the current location on the plane map, and looks down the plane map from the viewpoint at a predetermined look-down angle and spread angle. Converting to bird's-eye view map data, and when there is a scroll command, according to the command, the position of the viewpoint is changed before or after the current location and converted to the bird's-eye view map data, and the map display for moving bodies apparatus. In the map display apparatus for mobile bodies described in Claim 1 or 2 ,
An area for displaying the sky is formed at the top of the screen,
A map display apparatus for a moving body, comprising prohibiting means for prohibiting display of a current position mark in the empty area.

Images