JPH08234657A - Route guiding device for vehicle - Google Patents

Abstract

PURPOSE: To display easy-to-see character information from the periphery of the vehicle's current position up to a distance on a bird's-eye viewing road map. CONSTITUTION: This device transforms road map stored in a road map storing means to a bird's-eye system road map and plots the transferred map on a display means, and also draws the character information stored in a character information storing means at a corresponding position to the bird's-eye view with all the characters at the same height. Then, the device draws the character information corresponding to a narrow area in the character information of plural hieralchies for periphery of the current position of the vehicle, and plots character information corresponding to a wide area for a distance from the current position of the vehicle. Also, when the character information corresponding to the wide area is plotted before the character information corresponding to the narrow area is drawn but both character information are laid over the other, the former is overwritten by the latter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle route guide device for displaying a route to a destination on a bird's-eye view road map to guide an occupant.

[0002]

2. Description of the Related Art A vehicle route guidance device is known in which a so-called bird's-eye view type road map is displayed on the display so that the road in the traveling direction is looked down from above the rear of the vehicle. For example, Japanese Patent Laid-Open No. 2-2
44188 gazette). This type of vehicle route guidance device guides an occupant by displaying an optimal route to a destination and the current location of the vehicle on a bird's-eye view road map centering on the traveling direction.

By the way, comparing a conventional plan map as shown in FIG. 15 (b) with a bird's eye view type road map as shown in FIG. 15 (a), the conventional plan map shows the road at any position on the display screen. Although the map is displayed at the same scale, in the bird's-eye view road map, the road map is enlarged and displayed around the current position of the vehicle on the lower side of the display screen, and the road map is reduced as the distance from the current position on the upper side of the display screen increases. In the conventional floor plan, no matter how much text information such as administrative boundaries, facility names, lakes and marshes is displayed on the road map on the display screen, the text information will be dense unless a large amount of text information is displayed. It's not hard to see. However, in the bird's-eye view road map, the road map itself is reduced as it moves away from the current location above the display screen, so if the text information is displayed above the display screen by the same processing as in the vicinity of the current location below the display screen, There is a problem that the road map becomes difficult to see because the character information becomes dense or the character information overlaps each other.

An object of the present invention is to provide a vehicular route guide device which is capable of easily displaying character information from the vicinity of the present location of a vehicle on a road map of a bird's-eye view system to a distant place.

[0005]

In order to achieve the above object, the invention of claim 1 is a road map storage means for storing a road map, and a character information storage means for storing character information displayed on the road map. And a map converting means for converting the road map of the road map storing means into a bird's-eye view type road map, and the bird's-eye view type road map converted by the map converting means is drawn on the display means and the character information storing means And a drawing means for drawing the character information of the above at a corresponding position of the bird's-eye view road map drawn on the display means.
In the vehicle route guidance device according to claim 2, the character information stored in the character information storage means is classified into a plurality of layers from information corresponding to a narrow area to information corresponding to a wide area, and the character information is stored by the drawing means. In the vicinity of the current location of the vehicle, character information corresponding to a narrow area in the character information of the plurality of layers is drawn, and character information corresponding to a wide area is drawn far from the current location of the vehicle. is there. 4. The vehicle route guidance device according to claim 3, wherein the display screen of the display means is divided into a plurality of display areas, and the drawing means draws character information corresponding to a narrow area in the display area near the current position of the vehicle. The character information corresponding to a large area is drawn in the display area far from the current location of the vehicle. 5. The vehicle route guidance device according to claim 4, wherein the drawing means draws character information corresponding to a wide area and then draws character information corresponding to a narrow area to correspond to the character information corresponding to the narrow area and the wide area. When the character information corresponding to the narrow area overlaps the character information corresponding to the wide area, the character information corresponding to the wide area is overwritten. According to a fifth aspect of the present invention, there is provided the vehicle route guidance device, wherein the drawing means draws all the characters at the same character height when drawing the character information.

[0006]

According to the vehicle route guiding apparatus of claim 1, the road map stored in the road map storage means is converted into a bird's-eye view road map, and the converted bird's-eye view road map is drawn on the display means. The character information stored in the character information storage means is drawn at a corresponding position of the bird's-eye view road map drawn on the display means. In the vehicle route guidance device according to claim 2, character information corresponding to a narrow area of the character information of a plurality of layers is drawn around the current location of the vehicle, and character information corresponding to a wide area is distant from the current location of the vehicle. Draw information. In the vehicle route guidance device according to claim 3, character information corresponding to a narrow area is drawn in a display area near the current location of the vehicle, and character information corresponding to a wide area is drawn in a display area far from the current location of the vehicle. . In the vehicle route guidance device according to claim 4, after the character information corresponding to the wide area is drawn, the character information corresponding to the narrow area is drawn, and the character information corresponding to the narrow area and the character information corresponding to the wide area are generated. When they overlap, the character information corresponding to the wide area is overwritten on the character information corresponding to the wide area. In the vehicle route guiding device according to the fifth aspect, all characters are drawn at the same character height when drawing the character information.

[0007]

FIG. 1 is a functional block diagram showing the structure of an embodiment. The vehicle route guidance device of this embodiment is mainly composed of a microcomputer. The azimuth sensor 1 detects the traveling direction of the vehicle, and the detected traveling direction information is A / D.
CPU 4 via converter 2 and interface circuit 3
Send to. The vehicle speed sensor 5 generates a pulse signal for each predetermined traveling distance of the vehicle, and C
Output to PU4. The CPU 4 counts the number of pulses of this pulse signal to detect the traveling distance of the vehicle. GPS
The receiver 6 is a receiver of a position detection system using a satellite, and sends information such as the current position of the vehicle and the traveling direction to the CPU 4 via the interface circuit 3. The key 7 is an operation member for setting a destination of the vehicle and the like, and is connected to the CPU 4 via the interface circuit 3.

The CD-ROM 8 is a storage device for storing road map data and character data, is connected to the CPU 4 via the interface SCSI controller 9, and responds to a road map read command from the CPU 4 to specify a road map in a designated range. Data and character data are sent to the CPU 4. The display 10 for displaying the road map is connected to the CPU 4 via the graphic controller 11,
Character information, the optimal route to the destination, and the vehicle's current location mark are displayed superimposed on a bird's-eye view road map. VR
The AM 12 stores bird's-eye view road map data and character data, and outputs the data to the display 10 via the graphic controller 11 in accordance with a display command from the CPU 4. Further, the CPU 4 includes a RAM 13 for temporarily storing various data and a ROM for storing a control program described later.
14 and the like are connected. The CPU 4 executes a processing program to be described later to convert the two-dimensional plane road map data into bird's-eye view road map data, draws the bird's-eye view road map on the display 10, and displays text information on the map. The current position of the vehicle and the optimum route to the destination are superimposed and drawn.

FIG. 2 shows the relationship between a two-dimensional plane road map and a bird's-eye view road map. A two-dimensional road map with east in the + X axis direction and north in the + Y axis direction, XY
Consider an XYZ three-dimensional coordinate system that is represented on a plane and the sky above the road on the XY plane is taken in the positive direction of the Z axis orthogonal to the XY plane. A viewpoint E (VX, VY, VZ) is set above the point that is a predetermined distance away from the current position of the vehicle to the destination, and the road map on the XY plane is looked down from this viewpoint E along the line of sight EF. To do. The angle formed by the line of sight EF and the XY plane is referred to as the looking down angle θ, and the angle formed by the straight line E′F obtained by projecting the line of sight EF on the XY plane and the + X axis is called the line of sight direction φ. Display 1 on a plane perpendicular to the line of sight EF
The display frame abcd of 0 is set, and the viewpoint E (VX, VY, V
When the road map on the XY plane is looked down from Z) through the display frame abcd, the road map in the trapezoidal ABCD range can be seen. This range ABCD is the display area of the road map. The line of sight EF is the display frame ab of the display 10.
If it is set to pass through the center of cd and look down at the vehicle, the current location of the vehicle is displayed at the center of the display frame abcd. In this case, the lower display frame abgh of the display 10 corresponds to the display area ABGH, and the road map of the narrow area ABGH is displayed in the lower display frame abgh. The upper display frame ghdc corresponds to the display area GHDC, and the road map of the wide area GHDC is displayed in the upper display frame ghdc. That is, the road map in the range close to the viewpoint E is enlarged and displayed, and the road map is reduced and displayed as the distance from the viewpoint E increases. The current location of the vehicle is F (CX, CY). Current location of this vehicle F
(CX, CY) is located at the center of the side GH.

FIG. 3 is a flow chart showing a road map display program of one embodiment. The operation of the embodiment will be described with reference to this flowchart. When the main switch of the key 7 is turned on, the CPU 4 starts executing this control program. In step 100, the destination information set by the key 7 is read, and the following step 10
At 2, the current position and the heading of the vehicle are detected. The current position of the vehicle may be calculated by self-contained navigation or may be detected by GPS navigation. Also, both may be used in combination. The former calculates the traveling locus based on the traveling azimuth detected by the azimuth sensor 1 and the traveling distance measured by counting the pulse signals from the vehicle speed sensor 5, and specifies the current location by map matching. The latter is a GPS receiver 6
The current position and traveling direction calculated by are used. In step 104, the optimum route from the current position to the destination is calculated by a known route search method.

In step 106, the direction φ of the line of sight EF is calculated. For this line-of-sight direction φ, for example, the direction in which the distance of the optimum route displayed on the display 10 is maximum may be set, or the traveling direction of the vehicle may be simply set. Alternatively, the direction of the destination may simply be set. In the following step 108, the current position F (CX, C of the vehicle is
The position of the viewpoint E and the line of sight EF are determined so that Y) is displayed in the center of the display frame abcd of the display 10. In this embodiment, the Z coordinate VZ of the viewpoint E (hereinafter referred to as the viewpoint height) and the gaze angle θ are predetermined values set in advance.

In step 110, the display area ABC
Compute each vertex of D. FIG. 4 shows an XY plane at Z = 0 in the three-dimensional coordinate system shown in FIG. Viewpoint E (VX, V
A projection point E '(VX, VY) of Y, VZ) on the XY plane is calculated by the following equation.

[Equation 1] Even when the current position of the vehicle is displayed at a position other than the center of the display frame abcd, the viewpoint height VZ and the line-of-sight direction φ are constant, so that the relative relationship between the viewpoint E and the display area ABCD is uniquely determined. The projection point E'can be calculated with a slight modification to 1. For example, the current position of the vehicle is displayed in the display frame a.
In the case of displaying below the vertical center on the horizontal center line of bcd, θ may be selected so that the term of (Vz / tan θ) in Expression 1 becomes smaller.

Here, the XY coordinate system shown in FIG. 4 is translated so that the viewpoint projection point E '(VX, VY) becomes the origin,
The X'Y 'coordinate system is set as shown in FIG. further,
The X′Y ′ coordinate system is set by rotating the X′Y ′ coordinate system so that the line of sight is on the Y axis. As shown in FIG. 6, the width of the display frame abcd of the display 10 is set to 1
Let S be the vertical width, and DS be the distance from the viewpoint E (VX, VY, VZ) to the display frame abcd, and the half-spread angle α is the angle between the line of sight EF and the straight line Eg. X shown in FIG.
The display area ABCD of the Y coordinate system corresponds to the display area A "B" C "D" of the X "Y" coordinate system shown in FIG. The coordinates of each vertex of the display area A "B" C "D" in this new X "Y" coordinate system are given by the following equations.

[Equation 2]

Next, the coordinates of each apex of the display area A'B'C'D 'in the X'Y' coordinate system considering the line-of-sight direction φ are obtained. Since the X'Y 'coordinate system is a rotation of the X "Y" coordinate system, the display area A "calculated by Equation 2
The coordinates of each vertex of B "C" D "are converted by rotating the coordinate axes.

(Equation 3) Further, each vertex of the display area in the XY coordinate system is calculated based on the calculated vertex coordinates of the display area A'B'C'D 'in the X'Y' coordinate system. Since the XY coordinate system is a translation of the X'Y 'coordinate system, Equation 3
The vertex coordinates of the display area A′B′C′D ′ calculated by the above are translated by VX in the X-axis direction and VY in the Y-axis direction for coordinate conversion.

[Equation 4]

Since the display area ABCD on the road map on the two-dimensional plane XY can be obtained, step 11
In step 2, the road map data and the character data stored in the CD-ROM 8 are read into the RAM 13 from the road map data and the character data in a range including the display area ABCD. For road map data and character data, nationwide JIS-X041
It is managed by being divided into small sections (hereinafter referred to as regional meshes) defined as 0, and reading of road map data and character data from the CD-ROM 8 is performed in units of regional meshes. The road map data is dataized by nodes that indicate intersections, flex points, etc. on roads, and links that connect the nodes to each other, and are stored together with hierarchical level information based on the position coordinates of each node and each link and the road type. Has been done. In addition to the road information, this road map data also includes information represented by lines such as railroads, lakes, and parks.

Character data such as the administrative world and its place names, railway and station names, main facilities, lakes and marshes, historic sites are stored separately from the road map data. Figure 8 shows a CD-ROM
8 shows a part of the character data stored in FIG. The character data includes character information, XY coordinates indicating its display position, and a hierarchical level. The hierarchical level "1" represents information corresponding to the narrowest area, the level "3" represents information corresponding to the widest area, and the level "2" represents intermediate information.
For example, the administrative community sets hierarchical levels as shown in FIG.

Next, in step 114, the CD-R
The XY plane road map data read from the OM 8 is coordinate-converted into bird's-eye view road map data to be displayed on the display 10. The coordinate conversion from the two-dimensional plane road map to the bird's-eye view road map will be described in detail later. In step 116, the bird's-eye view road map data is transferred to the V-RAM 12, drawn on the display 10 via the graphic controller 11, and the car mark indicating the current position of the vehicle and the optimum route to the destination calculated in the above step are displayed. Is superimposed on the bird's-eye view road map being displayed. In step 118, a character information drawing routine, which will be described later, is executed to draw the character information by superimposing it on the bird's-eye view road map being displayed. Note that the road map is converted into a bird's-eye view, but the text information is not converted into the bird's-eye view. The drawing process of this character information will be described later. In step 120, it is determined whether or not the vehicle has moved a predetermined distance or whether the vehicle has rotated a predetermined angle. If there is movement or rotation of the vehicle, the process returns to step 106 and the above processing is repeated to create a bird's eye view road map. Update.

Next, the coordinate conversion from the plane road map data in the XY coordinate system to the bird's-eye view road map data displayed on the display 10 will be described. FIG. 7 shows an EXEYEZ coordinate system with the viewpoint E (VX, VY, VZ) as the origin and the line of sight EF as the −Z axis, an SXSY display coordinate system with the center of the display frame abcd of the display 10 as the origin, and a display area. The relationship with ABCD is shown. Here, if the coordinates of the arbitrary road map data P in the XY coordinate system are (MX, MY), as shown in FIG. 5, the point E '(VX, VY) is moved in parallel so that it becomes the origin (X (Y 'coordinate system), and the coordinates (MX ", M of the arbitrary data P in the X" Y "coordinate system rotated so that the line of sight (E'F) overlaps the Y axis.
Y ”) is

(Equation 5) Is required. Next, the coordinates (MX ", MY") of the data P in this X "Y" coordinate system are calculated by the following formula: EXEYEZ
Convert to the coordinates of the coordinate system (EX1, EY1, EZ1).

(Equation 6) It should be noted that when Equation 5 is substituted into Equation 6 and transformed, it is expressed as follows.

(Equation 7) Furthermore, the coordinates of the data P in the EXEYEZ coordinate system (EX
1, EY1, EZ1) is converted into coordinates (SX1, SY1) of the SXSY coordinate system by the following equation.

[Equation 8] SX1 = -DS / EX1 / EZ1, SY1 = -DS / EY1 / EZ1

10 and 11 are flowcharts showing the character information drawing routine. The character information drawing process for the bird's-eye view road map will be described with reference to this flowchart. In step 200, step 1 of FIG.
At 12, the arbitrary data (mx, my) is read from the character data read from the CD-ROM 8 and stored in the RAM 13. Here, in step 112, as shown in FIG. 12, the area mesh M1 including the display target area ABCD is displayed.
It is assumed that road map data and character data in the range of to M4 have been read. In step 202, it is determined whether the read character data (mx, my) is within the conversion target area ABCD. If it is within the conversion target area ABCD, the process proceeds to step 204, and if not, the process proceeds to step 216.
In step 204, the coordinates of the character data (mx, my)
Is converted into X "Y" coordinates (mx ", my") by the above-mentioned mathematical expression 5.

In step 206, it is determined whether or not the Y "coordinate my" of the character data is less than or equal to a predetermined value L. Here, the predetermined value L is, as shown in FIG. 13, a linear Y "coordinate parallel to the X" axis that divides the display frame abcd of the display 10 into a display region near the current position of the vehicle and a display region distant from the current position. is there. For example, it is set to a value such that the display frame of the display 10 is vertically divided into 1: 7. If the coordinate my "is less than or equal to the predetermined value L, that is, if the coordinate of any character data is within the display area around the current position of the vehicle, the process proceeds to step 208, and if it is in the display region far from the current position, step 210.
Go to. If the coordinates of the character data are within the display area around the current location, in step 208, whether the hierarchical level of the character data is 1 or 2, that is, the character data should be displayed in the display area near the current location. It is determined whether or not the information corresponds to a narrow area. If it is the narrow area information, the process proceeds to step 212. If not, the process proceeds to step 216. On the other hand, when the coordinates of the character data are in the display area far from the current location, it is determined in step 210 whether the hierarchical level of the character data is 2 or 3, that is, the character data is displayed in the display area far from the current location. It is determined whether or not the information corresponds to a wide area that should be used. If it is wide area information, the process proceeds to step 212. If not, the process proceeds to step 216.

In step 212, equations 6 and 8 above are used.
Convert the X "Y" coordinates (mx ", my") of the character data to the coordinates (SX1, SY1) of the SXSY display screen coordinate system,
In the following step 214, the character data is stored in the RAM 13 together with the hierarchy level and the display screen coordinates. At this time, if the absolute value of the display screen coordinates SX1 is larger than 1/2 of the horizontal width of the display frame of the display 10, as shown in FIG. 12, the display area AB is present even within the conversion target area JKPQ.
Since it is outside the CD, such character data may be excluded. In step 216, it is determined whether or not the above processing has been completed for all the character data read in step 112. When the processing is completed, the process proceeds to step 218, and if there is unprocessed data, the process returns to step 200. The above process is repeated for unprocessed data.

When the above processing is completed for all the character data read from the CD-ROM 8 to the RAM 13, the data of the hierarchical level 3 is extracted from the character data stored in the RAM 13 at step 218. , The display screen coordinates (SX1, SY) of the character data on the display 10 via the graphic controller 11.
Draw at position 1). In the following step 220, RA
The data of the hierarchy level 2 is extracted from the character data stored in M13, and the graphic controller 11
The character data is drawn on the display 10 at the position of the display screen coordinates (SX1, SY1). In addition, the data of the hierarchical level 3 drawn in step 218 and step 2
When the data of the hierarchy level 2 drawn at 20 overlaps, the character data of the middle level of the hierarchy level 2 corresponding to the narrower area is overwritten on the character data corresponding to the wide area of the hierarchy level 3. For example, when “Kanagawa” of hierarchy level 3 and “Yamato” of hierarchy level 2 shown in FIG. 8 overlap,
As shown in FIG. 14, “Yamato” of hierarchy level 2 is overwritten on “Kanagawa” of hierarchy level 3. In step 222, the data of the hierarchical level 1 is extracted from the character data stored in the RAM 13, and is drawn through the graphic controller 11 at the position of the display screen coordinates (SX1, SY1) of the character data of the display 10. . In addition,
Wide-area corresponding character data of hierarchy level 3 drawn in step 218, middle-area corresponding character data of hierarchy level 2 drawn in step 220, and narrow-area corresponding character data of hierarchy level 1 drawn in step 222. In case of overlapping, the data of the hierarchical level 1 is overwritten on the character data of the hierarchical level 3 or 2. For example, when "Yokohama" of hierarchy level 2 and "Kibigaoka" of hierarchy level 1 shown in FIG. 8 overlap, "Yokohama" of hierarchy level 2 as shown in FIG.
Overwrite "Kibigaoka" in the hierarchy level 1 above.

When the character information is drawn, it is easier to see the character by filling the background of the character with the same color as the background color of the road map and drawing the character on it. Further, the characters to be used should be the same font in all display areas, or at least have the same character height.

As described above, the road map stored in the CD-ROM 8 is converted into a bird's-eye view type road map, and the converted bird's-eye view type road map is drawn on the display 10 and stored in the CD-ROM 8. Since the existing character information is drawn at the corresponding position of the bird's-eye view road map drawn on the display 10, the shape of the character information is not converted into the bird's-eye view map and is drawn on the bird's-eye view road map as it is. Moreover, since only the road map is converted into a bird's-eye view, the conversion processing amount is reduced and the drawing time can be shortened. In addition, around the current location of the vehicle, the text information corresponding to the narrow area of the text information of multiple layers is drawn, and the text information corresponding to the wide area is drawn far from the current location of the vehicle. Local character information corresponding to the narrow area where it is easy to judge the traveling direction at the intersection is displayed in the surrounding area, and character information corresponding to the wide area where it is easy to judge the situation of the target local area is displayed in the distant area, and it is displayed to passengers. Useful character information can be provided appropriately. Furthermore, since the character information corresponding to the narrow area is drawn in the display area around the current position of the vehicle, and the character information corresponding to the wide area is drawn in the display area distant from the current position of the vehicle, each area is displayed. Since it is only necessary to distribute the character information having a predetermined hierarchical structure, the processing of the character data is simplified and the drawing time can be shortened. When the character information corresponding to the narrow area is drawn after drawing the character information corresponding to the wide area, and the character information corresponding to the narrow area overlaps with the character information corresponding to the wide area, the character information corresponding to the wide area is placed on top of the character information corresponding to the wide area. Since the character information corresponding to the narrow area is overwritten, the local information corresponding to the narrow area, which is useful for the occupant, can be preferentially displayed by a simple algorithm of drawing in the order of a predetermined hierarchical level. it can. Furthermore, when the character information is drawn, all the characters are drawn with the same font or the same character height, so that the character information is easy to see.

In the above-mentioned embodiment, the character data is 3
Although an example in which layers are hierarchized is shown, the hierarchical structure of character data is not limited to the above-mentioned embodiment. Further, in the above-described embodiment, the example in which the display screen is divided into the area around the current location and the area far from the current location has been shown, but the number of divisions of the display screen is not limited to the above-described embodiment. Further, in the above-described embodiment, the road map data and the character data are stored in the same storage device (CD-
Although an example in which the data is stored in the ROM) is shown, the data may be stored in different storage devices. Further, the storage device for the road map and the character data is not limited to the CD-ROM.

In the configuration of the above embodiment, the CD-RO
M8 is a road map storage means and character information storage means, C
PU4 constitutes a map conversion means and a drawing means, respectively.

[0027]

As described above, according to the invention of claim 1, the road map stored in the road map storage means is converted into a bird's-eye view road map, and the converted bird's-eye view road map is displayed. The shape of the character information is converted into a bird's-eye view because the character information stored in the character information storage means is drawn at the corresponding position of the bird's-eye view road map drawn on the display means. Instead, the text information is drawn as it is on the road map of the bird's-eye view method so that the character information is easy to see, and since only the road map is converted to the bird's-eye view, the conversion processing amount is reduced and the drawing time can be shortened. According to the invention of claim 2, character information corresponding to a narrow area in the character information of a plurality of layers is drawn around the current position of the vehicle,
Character information corresponding to a wide area is drawn far from the current position of the vehicle, so local character information corresponding to a narrow area where it is easy to determine the direction of travel at an intersection is displayed around the current position, and The character information corresponding to a wide area where the situation of the target local area can be easily judged is displayed, and it is possible to appropriately provide useful character information to the occupant. According to the invention of claim 3, character information corresponding to a small area is drawn in the display area around the current position of the vehicle, and character information corresponding to a wide area is drawn in the display area distant from the current position of the vehicle. Therefore, in addition to the effect of the second aspect, it is only necessary to distribute the character information having a predetermined hierarchical structure to the respective display areas, the processing of the character data is simplified, and the drawing time can be shortened. According to the invention of claim 4, when the character information corresponding to the narrow region is drawn after the character information corresponding to the wide region is drawn and the character information corresponding to the narrow region overlaps with the character information corresponding to the wide region. Is designed to overwrite the text information corresponding to the narrow area on top of the text information corresponding to the wide area. Local information can be displayed preferentially. According to the invention of claim 5, all the characters are drawn at the same character height when drawing the character information, so that the character information is easy to see.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment.

FIG. 2 is a diagram showing a relationship between a two-dimensional plane road map and a bird's-eye view road map.

FIG. 3 is a flowchart showing a road map display program.

FIG. 4 is a diagram showing a display area of a road map on an XY two-dimensional plane.

5 is an X'Y 'coordinate system obtained by translating the XY two-dimensional plane map coordinate system shown in FIG. 4 so that the viewpoint is the origin, and X "Y rotated so that the line-of-sight direction overlaps the Y axis. "A diagram showing a coordinate system.

FIG. 6 is a diagram showing a relationship between a viewpoint E and a display frame abcd of a display.

FIG. 7: EX with the viewpoint E as the origin and the line of sight EF as the −Z axis
The figure which shows the relationship between an EYEZ coordinate system, the SXSY display coordinate system which makes an origin the center of the display frame of a display, and a display area ABCD.

FIG. 8 is a diagram showing a part of character data stored in a storage device.

FIG. 9 is a diagram showing hierarchical levels of administrative circles.

FIG. 10 is a flowchart showing a character information drawing routine.

11 is a flowchart showing a character information drawing routine following FIG.

FIG. 12 is a diagram showing a character data reading area, a display target area, and a display area.

FIG. 13 is a diagram showing division of a display area.

FIG. 14 is a diagram showing a display example of character information.

FIG. 15 is a diagram showing a planar road map and a bird's-eye view road map.

[Explanation of symbols]

 1 Direction Sensor 2 A / D Converter 3 Interface Circuit 4 CPU 5 Vehicle Speed Sensor 6 GPS Receiver 7 Key 8 CD-ROM 9 SCSI Controller 10 Display 11 Graphic Controller 12 V-RAM 13 RAM 14 ROM 15 Receiver 16 Extended I / O

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G06T 15/20 G06F 15/62 335 G08G 1/0969 9365-5H 15/72 455

Claims (5)

[Claims] 1. A road map storage means for storing a road map, a character information storage means for storing character information to be displayed on the road map, and a road map of the road map storage means converted to a bird's-eye view road map. The map conversion means and the bird's-eye view type road map converted by the map conversion means are drawn on the display means, and the character information of the character information storage means corresponds to the bird's-eye view type road map drawn on the display means. A route guidance device for a vehicle, comprising: a drawing unit that draws at a position. 2. The vehicle route guiding apparatus according to claim 1, wherein the character information stored in the character information storage means is classified into a plurality of layers from information corresponding to a narrow area to information corresponding to a wide area. The drawing means draws character information corresponding to a narrow area in the character information of the plurality of layers around the current position of the vehicle, and character information corresponding to a wide area far from the current position of the vehicle. A route guidance device for a vehicle, wherein: 3. The vehicle route guiding apparatus according to claim 2, wherein the display screen of the display means is divided into a plurality of display areas, and the drawing means is a narrow area in a display area near the current position of the vehicle. A vehicle route guidance device, which draws corresponding character information and draws character information corresponding to a wide area in a display area far from the current position of the vehicle. 4. The vehicle route guiding apparatus according to claim 2, wherein the drawing unit draws character information corresponding to a wide area and then draws character information corresponding to a narrow area, When the character information corresponding to the area and the character information corresponding to the wide area overlap, the character information corresponding to the wide area is overwritten with the character information corresponding to the narrow area. . 5. The vehicle route guiding apparatus according to claim 1, wherein the drawing unit draws all characters at the same character height when drawing the character information. Characteristic vehicle route guidance device.