JP3491370B2 - Route guidance device for vehicles - Google Patents

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, JP-A 1-2
63688 gazette). In this type of vehicle route guidance device, a road map necessary for displaying a bird's-eye view road map on the entire display screen from road map data stored in a large-capacity storage device such as a CD-ROM. All the data is read into a temporary storage memory such as RAM, converted into a bird's-eye view road map, and drawn on the display.

By the way, when displaying a wide range road map with a conventional vehicle route guidance device, all road map data in a wide display area is temporarily read into a memory for temporary storage, and the read road map data is compressed. It is processing. For example, from the road map data, data corresponding to a wide range on the road map such as highways and national roads is extracted, excluding data corresponding to a narrow range on the road map such as city hall roads and narrow streets. There is. However, in the conventional vehicle route guidance device, when displaying a wide range of road maps, the road map data in the display area to be read into the memory for temporary storage has a large capacity, so a large capacity memory must be prepared. In addition, there is a problem that the cost of the device is increased and the load of the microcomputer is increased because a large amount of data is read. Also, in order to reduce the cost of the device, if the capacity of the memory for temporary storage is selected based on the display area assuming general usage, it is not possible to read road map data that exceeds the display area. , It becomes impossible to display a road map in a wider range than the expected usage. Furthermore, when the vehicle moves at high speed or when changing the traveling direction at an intersection, etc., the road map of the bird's eye view method is drawn after reading all the road map data of the new display area,
There is also a problem that it takes a lot of time to draw and a display delay occurs when the vehicle moves or rotates.

An object of the present invention is to provide a vehicle route guidance device which preferentially displays a road map in an area of high importance.

[0005]

In order to achieve the above object, the invention of claim 1 has a storage means for storing a flat road map, a display means for displaying a bird's-eye view road map, and the storage means. The present invention is applied to a route guidance device for a vehicle, which includes a drawing means for converting a stored flat road map into a bird's-eye view road map and drawing it on the display means. And
The display screen of the display means for displaying one bird's-eye view road map is divided into upper and lower areas by horizontal line segments, and the lower area is divided.
Set the area as the priority display area that displays the road map with priority.
And set the upper area as the non-priority display area.
Includes a range setting means, said drawing means, road bird's eye view mode giving priority to the priority display road map of the region corresponding to the region of the plane road map stored in said storage means to said non-priority display area It is converted into a map and drawn on the display means. According to the invention of claim 2, a storage means for storing the plane road map and a plane perpendicular to the line of sight are looked down along the line of sight of a predetermined gaze angle from a viewpoint set at a predetermined position above the rear of the vehicle. Set the display screen of the display means above,
A display area calculation means for calculating a display area on the flat road map viewed through the display screen; and a display area calculated by the display area calculation means in the flat road map stored in the storage means. The present invention is applied to a route guidance device for a vehicle provided with map conversion means for converting a flat road map into a bird's-eye view road map, and drawing means for drawing the bird's-eye view road map converted by the map conversion means on the display screen of the display means. It The display screen of the display means is displayed in the upper and lower areas.
The road map is divided into
Set the display area to the first display area and set the upper area to the non-priority table.
A display area calculation means for calculating a priority display area on the planar road map viewed through the priority display area in the display screen, and the map conversion means stores the storage area. Among the plane road maps stored in the means, the plane road map in the priority display area calculated by the display area calculation means is converted into the bird's-eye view road map by giving priority to the non-priority display area, and the drawing means is The bird's-eye view road map converted by the map conversion means is drawn in the priority display area of the display screen. In the vehicle route guidance device according to the third aspect of the present invention, the area including the current position of the vehicle is set as the priority display area. In the vehicle route guiding device according to the fourth aspect, an area including an arbitrary point is set as the priority display area. According to a fifth aspect of the vehicle route guiding device, the priority display area is an area close to a point where the viewpoint of the bird's-eye view is projected on the planar road map. According to a sixth aspect of the present invention, there is provided a vehicle route guidance device in which the priority display area is an area divided by a line segment in a horizontal direction of the display screen. Claim 7
The vehicle route guidance device of, on the plane road map viewed through the non-priority display area in the display screen by the display area calculation means after the bird's-eye view road map is drawn in the priority display area of the display screen. A non-priority display area is calculated, and a plane road map in the non-priority display area calculated by the display area calculation means out of the plane road maps stored in the storage means by the map conversion means is a bird's-eye view road. The map is converted into a map, and the bird's-eye view road map converted by the map converting unit is drawn by the drawing unit in a non-priority display area of the display screen. The vehicle route guidance device according to claim 8 comprises distance detection means for detecting a traveling distance of the vehicle and direction detection means for detecting a traveling direction of the vehicle, and a bird's-eye view road map is drawn in a priority display area of the display screen. After that, when the traveling of the vehicle of a predetermined distance or more is detected by the distance detecting means or the rotation of the vehicle of a predetermined angle or more is detected by the azimuth detecting means, a bird's-eye view road map for the non-priority display area. No drawing is performed, and the bird's-eye view road map of the priority display area is updated by the display area calculation means, the map conversion means, and the drawing means. According to a ninth aspect of the present invention, a storage unit that stores a flat road map in units of regional meshes, a temporary storage unit that temporarily stores the flat road map read from the storage unit, and a predetermined space above the rear of the vehicle. A plane road map is looked down along a line of sight of a predetermined gaze angle from a viewpoint set to a position, a display screen of a display means is set on a plane perpendicular to the line of sight, and a display area on the plane road map seen through the display screen. Display area calculation means for calculating, and reading means for reading out a planar road map in a unit of regional mesh including a planar road map of the display area calculated by the display area calculation means from the storage means and storing the planar road map in the temporary storage means. Converting a plane road map in the display area calculated by the display area calculation unit out of the plane road maps stored in the temporary storage unit into a bird's-eye view road map A map conversion means, applies the converted bird's-eye view road map by the map transformation means in a vehicle navigation system that includes a drawing means for drawing on the display screen of the display unit. Then, the display screen of the display means is divided into horizontal line segments.
It is divided into upper and lower areas, and the lower area is given priority
Set the priority display area to display the figure and
Equipped with area setting means for setting the area to the non-priority display area ,
The display area calculating means calculates a priority display area on the flat road map viewed through the priority display area in the display screen, and the map converting means calculates the priority display area of the flat road map stored in the temporary storage means. A plane road map in the priority display area calculated by the display area calculation means in the above is converted into a bird's-eye view road map by giving priority to the non-priority display area, and the drawing means is a bird's-eye view converted by the map conversion means. A road map is drawn in the priority display area of the display screen. Claim 1
In the vehicle route guidance device of No. 0, after the bird's-eye view road map is drawn in the priority display area of the display screen, the display area calculation means displays the plane road map viewed through the non-priority display area in the display screen. Calculate the non-priority display area of
The map conversion means converts a plane road map in the non-priority display area calculated by the display area calculation means out of the plane road maps stored in the temporary storage means into a bird's-eye view road map, and draws the map. By the means, the bird's-eye view road map converted by the map converting means is drawn in the non-priority display area of the display screen. The vehicle route guidance device according to claim 11, wherein when the map conversion means reads only part of the planar road map corresponding to the non-priority display area into the temporary storage means, the map is read out. A part of the planar road map is converted into a bird's-eye view road map, and the drawing means draws the bird's-eye view road map converted by the map converting means in a non-priority display area of the display screen. Claim 12
The vehicle route guidance device includes a distance detecting means for detecting a traveling distance of the vehicle and an azimuth detecting means for detecting a traveling azimuth of the vehicle, and after the bird's-eye view road map is drawn in the priority display area of the display screen. When the traveling of the vehicle of a predetermined distance or more is detected by the distance detecting means, or the rotation of the vehicle of a predetermined angle or more is detected by the azimuth detecting means,
The bird's-eye view road map is not drawn in the non-priority display area, and the bird's-eye view road map of the priority display area is updated by the display area calculation means, the map conversion means, and the drawing means.

[0006]

In the vehicle route guiding apparatus according to claim 1, the display screen of the display means for displaying one bird's-eye view road map is displayed in the horizontal direction.
It is divided into upper and lower areas by line segments, and the lower area is given priority.
While setting it as the priority display area for displaying the road map,
The upper area is set as the non-priority display area, and the road map of the area corresponding to the priority display area in the flat road map stored in the storage means is given priority over the non-priority display area to the bird's-eye view road map. It is converted and drawn on the display means. The route guidance device for a vehicle according to claim 2, wherein the display screen is set on a plane perpendicular to the line of sight of the plane road map looking down from the viewpoint behind the vehicle, and the display area on the plane road map seen through the display screen from the viewpoint. Is calculated, and when converting the flat road map in this display area into a bird's-eye view road map and drawing it on the display screen, the display screen is divided into upper and lower areas, and the lower area is
If you set it to the priority display area that preferentially displays the road map
In both cases , the upper area is set as the non-priority display area, the priority display area on the flat road map viewed through the priority display area of the display screen is calculated, and the flat road map in this priority display area is set as the non-priority display area. Is converted into a bird's-eye view road map and drawn in the priority display area of the display screen. Claim 3
In the vehicle route guidance device of, the plane road map of the area corresponding to the priority display area including the current location of the vehicle in the plane road map is converted into the bird's-eye view road map by giving priority to the non-priority display area, and the display screen has priority. Draw in the display area. In the vehicle route guidance device according to claim 4, the plane road map of the area corresponding to the priority display area including an arbitrary point in the plane road map is converted into the bird's-eye view road map by giving priority to the non-priority display area and displayed. Draw in the priority display area of the screen. In the route guidance device for a vehicle according to claim 5, the plane road map in the area corresponding to the priority display area near the point where the viewpoint of the bird's-eye view is projected on the plane road map in the plane road map is prioritized over the non-priority display area. Then, it is converted into a bird's-eye view road map and drawn in the priority display area of the display screen. In the route guidance apparatus for a vehicle according to claim 6, in the plane road map, the plane road map of the area corresponding to the priority display area divided by the horizontal line segments of the display screen is prioritized over the non-priority display area. Bird's-eye view Converted to a road map and drawn in the priority display area on the display screen. In the vehicle route guidance device according to claim 7, after the bird's-eye view road map is drawn in the priority display area of the display screen, the non-priority display area on the flat road map viewed through the non-priority display area in the display screen is calculated. At the same time, the plane road map in this non-priority display area is converted into a bird's-eye view road map and drawn in the non-priority display area on the display screen.
In the vehicle route guiding device according to claim 8, after the bird's-eye view road map is drawn in the priority display area of the display screen, the traveling of the vehicle over a predetermined distance or the rotation of the vehicle over a predetermined angle is detected. Then, the bird's-eye view road map for the non-priority display area is not drawn, the priority display area on the plane road map is calculated, and the plane road map in the priority display area is converted to the bird's-eye view road map, and the display screen is displayed. Update the bird's-eye view road map in the priority display area. The route guidance device for a vehicle according to claim 9, wherein the display screen is set on a plane perpendicular to the line of sight of the plane road map looking down from the viewpoint behind the vehicle, and the display area on the plane road map seen through the display screen from the viewpoint. And the plane road map of the area mesh unit including the plane road map of this display area is read from the storage means and stored in the temporary storage means, and is displayed in the plan view road map stored in the temporary storage means. When converting a flat road map in a region into a bird's-eye view road map and drawing it on the display screen, the display screen is divided into upper and lower regions by horizontal line segments.
Priority display to display the road map preferentially in the lower area
Area is set and the upper area is a non-priority display area
Is set , the priority display area on the flat road map viewed through the priority display area of the display screen is calculated, and the flat road map in the priority display area among the flat road maps stored in the temporary storage means is not The bird's-eye view road map is converted with priority over the priority display area and drawn in the priority display area of the display screen.
In the vehicle route guidance device according to claim 10, after the bird's-eye view road map is drawn in the priority display area of the display screen, the non-priority display area on the flat road map viewed through the non-priority display area in the display screen is calculated. In addition, the plane road map in the non-priority display area of the plane road map stored in the temporary storage means is converted into a bird's-eye view road map, and the converted bird's-eye view road map is drawn in the non-priority display area of the display screen. . In the vehicle route guiding apparatus according to claim 11, when only a part of the planar road map corresponding to the non-priority display area is read out to the temporary storage means, a part of the read planar road map is a bird's-eye view. It is converted into a road map, and the converted bird's-eye view road map is drawn in the non-priority display area of the display screen. In the vehicle route guiding apparatus according to claim 12, after the bird's-eye view road map is drawn in the priority display area of the display screen, the traveling of the vehicle over a predetermined distance or the rotation of the vehicle over a predetermined angle is detected. Then, the bird's-eye view road map for the non-priority display area is not drawn, the priority display area on the plane road map is calculated, and the plane road map in the priority display area is converted to the bird's-eye view road map, and the display screen is displayed. Update the bird's-eye view road map in the priority display area.

[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, 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 store the road map data in the specified range in the CPU 4. Send to. The display 10 for displaying the road map is CP via the graphic controller 11.
It is connected to U4 and displays the optimum route to the destination and the current position mark of the vehicle in a superimposed manner on the bird's eye view type road map.
The V-RAM 12 stores road map data of a bird's-eye view method and outputs it to the display 10 via the graphic controller 11 according to a display command from the CPU 4. Further, the CPU 4 has an RA for temporarily storing various data.
ROM 14 for storing M13 and a control program described later
Etc. 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.

The conversion process from a flat road map to a bird's-eye view road map will now be described. FIG. 2 shows the relationship between a two-dimensional plane road map and a bird's-eye view road map. A three-dimensional XYZ map in which the plane road map is expressed on the XY plane with the east in the + X axis direction and the north in the + Y axis direction, 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. Consider the coordinate system. Viewpoint E (VX, VY, above the point a certain distance away from the current position of the vehicle to the destination)
VZ) and set XY along the line of sight EF from this viewpoint E
We should look down at the road map on the plane. Eyes EF and X
The angle formed by the Y plane is called 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. The display frame abcd of the display 10 is set on a plane perpendicular to the line of sight EF, and the viewpoint E (VX,
When the road map on the XY plane is looked down from (VY, VZ) 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.

Next, each vertex of the display area ABCD is calculated. FIG. 3 shows an XY plane at Z = 0 in the three-dimensional coordinate system shown in FIG. A projection point E ′ (VX, VY) of the viewpoint E (VX, VY, 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. 3 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. 5, 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 the vertices 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]

Next, the coordinate conversion from the plane road map data in the XY coordinate system to the bird's eye view type road map data displayed on the display 10 will be described. FIG. 6 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. 4, 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] Required by. 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

Here, the display frame abc of the display 10
An area (hereinafter referred to as a priority display area) in which a bird's-eye view road map is preferentially displayed is set in d. Figure 7
(A) shows an example of area division of the display frame abcd of the display 10, and (b) shows a divided display area of the XY plane map coordinate system corresponding to the divided area of the display frame abcd. In this embodiment, a horizon line H parallel to the Sx axis is set at a predetermined position at the top of the display frame abcd, and a display screen area below the horizon line H is displayed by a line segment L parallel to the Sx axis. The area is divided into an area corresponding to 7/8 and an area corresponding to 1/8. As described above, in this embodiment, Sx
Since the current location of the vehicle is displayed at the origin of the Sy display screen coordinate system, the current location of the vehicle is included in the display screen area, and the bird's-eye view road map is displayed in this area with priority over the area. The display screen area of the display frame abcd corresponds to the divided display areas ',' of the XY plane map coordinate system shown in (b), respectively, and the line segment L'parallel to the X axis dividing the two display areas is displayed. It corresponds to the line segment L of the frame abcd.

That is, in this embodiment, the road map in the area'of the display area ABCD of the XY plane map coordinate system is converted into the bird's-eye view road map in preference to the road map in the area ', and displayed. Draw in area 10.
Thus, by dividing the display area ABCD by the line segment L ′ parallel to the X axis of the XY plane map coordinate system,
Correspondence between the priority display area of the XY plane map coordinate system 'and the priority display area of the SxSy display screen coordinate system becomes clear, and when the intersection of the line segment L'and the Y axis is Y1, it is included in the display area ABCD. Only the data of Y ≦ Y1 in the road map data to be converted needs to be converted into the bird's-eye view road map data with priority, so that the calculation for extracting the data of the priority display area 'can be simplified and the conversion time can be reduced. This reduces the drawing time of the bird's eye view. 7 (a) and 7 (b)
As is clear from the above, the priority display area of the display 10 occupies most of the display frame abcd, but the corresponding priority display area 'on the planar road map is the display area ABCD.
It is a small area inside. That is, most of the bird's-eye view of the display 10 including the current location of the vehicle can be drawn only by converting the data in the small area 'on the two-dimensional plane road map into the bird's-eye view road map data, and for the occupant. A detailed road map around the most important current location is displayed within a short time.

In this embodiment, the display frame abcd is divided by the line segment L parallel to the Sx axis, and the area including the current position of the vehicle is set as the priority display area. However, the area is divided by another method. Then, the priority display area may be set. For example, although it takes a little longer for the conversion time, an area having an arbitrary shape around the current location may be used as the priority display area. Further, the division ratio is not limited to 1: 7, and may be any ratio. Furthermore, although the area is empty, it is not necessary to set an empty area.

8 to 10 are flow charts showing a road map display program of one embodiment. The operation of one embodiment will be described with reference to these flowcharts. Key 7
When the main switch is turned on, the CPU 4 starts executing this display program. In step 100,
The destination information set by the key 7 is read, and in the next step 102, the current position and traveling direction of the vehicle are detected. The current location of the vehicle may be calculated by self-contained navigation or GPS
It may be detected by 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 GPS
The current position and traveling direction calculated by the receiver 6 are used.
In step 104, the optimum route from the current position to the destination is calculated by a well-known route search method.

In step 106, the direction φ of the line of sight EF
To calculate. 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. It should be noted that in this embodiment, the Z coordinate VZ of the viewpoint E and the looking-down angle θ
Is a predetermined value set in advance. In step 110, the coordinates of the vertices A, B, C, D of the display area are calculated by the method described above, and in the following step 112, the coordinates of the vertices R, S of the priority display area 'divided by the line segment L'. . In step 114, it is determined whether or not the data in the priority display area 'can be read into the RAM 13, that is, whether or not the capacity of the RAM 13 is larger than the capacity of the area'.
When the data in the priority display area 'cannot be read because the capacity is smaller, the process proceeds to step 116, the buzzer is sounded, a warning is displayed on the display, and the process is ended.

When the capacity of the RAM 13 is larger than the data capacity in the priority display area ', the process proceeds to step 120,
It is determined whether the road map data has already been read into the RAM 13. If the data has already been read, the procedure proceeds to step 122, and if not, step 124.
Go to. If any road map data has already been read in the RAM 13, in step 122, the RAM 1
It is determined whether or not the data in 3 includes the data in the priority display area '. If the data in the priority display area' is included, the process proceeds to step 126. If not, the process proceeds to step 124. It should be noted that the determination in step 122 is practically possible even if the data in the RAM 13 does not include all the data of the priority display area ', even if it is considered that the data is included if the missing amount is about several% of the total. There is no hindrance. When the road map data is not stored in the RAM 13, or when the stored road map data does not include the data of the priority display area ', in step 124, the road map data of the area mesh unit including the priority display area' R
Read into AM13.

The road map data is JIS-X04 nationwide.
Subdivision defined in 10 (hereinafter referred to as regional mesh)
The road map data is read from the CD-ROM 8 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. Furthermore, this road map data includes the administrative world and its place names,
It contains textual information such as railway and station names, major facilities, lakes, and historic sites. In this embodiment, as shown in FIG. 11, it is assumed that the road map data of the area meshes M1 to M4 including the priority display area 'is read into the RAM 13. In step 126, the flat road map data in the priority display area 'read in the RAM 13 is converted into the bird's-eye view road map data by the procedure described above. When the conversion to the bird's-eye view is completed, the bird's-eye view road map data of the priority display area 'is immediately transferred to the graphic controller 11 in step 128, and the bird's-eye view road map is drawn in the priority display area of the display 10.

In step 130, it is determined whether the vehicle has moved a predetermined distance or more, or has rotated the predetermined angle or more, and if there is movement or rotation of the vehicle, step 10
Returning to step 6, the drawing processing of the priority display area is repeated to update the bird's-eye view road map. Here, at the predetermined distance, the display 1 is moved as the vehicle moves or rotates.
It is only necessary to set a moving distance that the current position of the vehicle above 0 is deviated from the preset position (the center of the display 10 in this embodiment) by a predetermined distance or more. Further, the predetermined angle may be set to an appropriate angle at which the bird's-eye view road map should be updated as the vehicle rotates. When both the movement and the rotation of the vehicle are smaller than the predetermined values, it is not necessary to update the bird's-eye view, so that the process proceeds to step 131 and thereafter, and the data conversion and drawing processing of the non-priority display area 'are performed. Step 13
1, all data in the non-priority display area 'is RA
It is determined whether or not it is read in M13. At this point, the RAM 13 has a local mesh M as shown in FIG.
The road map data of 1 to M4 are read, and the data of the priority display area 'therein is converted into the bird's-eye view, and is drawn in the priority display area of the display 10. However, not all road map data of the non-priority display area 'is read in the RAM 13,
As shown in FIG. 12, the data of the non-priority display area 'is read as the data of the area mesh M3, but the data of the non-priority display area' is the area meshes M5, M7,
Since it is included in M8, it is not read into RAM13.

All data in the non-priority display area 'is RA
If it is read in M13, the process proceeds to step 132, and if not, the process proceeds to step 134. Height of viewpoint E VZ
Is high and the look-down angle θ is large, all the display areas ABCD fall within the range of the regional meshes M1 to M4 as shown by the broken line in FIG. 11, so in such a case, the process proceeds to step 132 and the non-priority display is performed. The data of the area 'is converted into bird's-eye view road map data, and is drawn in the non-priority display area of the display 10 in the following step 133. In this case, a bird's-eye view road map is drawn on the entire display frame abcd of the display 10. Then step 14
8, it is determined whether the vehicle has moved a predetermined distance or more, or whether the vehicle has rotated a predetermined angle or more. If there is movement or rotation of the vehicle, the process returns to step 106 to repeat the drawing process of the priority display area, Update the bird's eye view road map.

On the other hand, as shown in FIGS. 11 and 12,
Area mesh M1 read when drawing the priority display area
If the non-priority display area 'is not included in the range of to M4, the process proceeds to step 134, and it is determined whether or not a part of the data of the non-priority display area' is read in the RAM 13. Some data in the non-priority display area 'is stored in the RAM 13
If it is read in step 135, the flow advances to step 135 to convert the data of the non-priority display area'which has already been read in the RAM 13 into bird's-eye view road map data as shown in FIG. Then, in step 136, a bird's-eye view type road map is drawn in the non-priority display area of the display 10. At this point, a bird's-eye view type road map is drawn in the entire range of the priority display area and a part of the non-priority display area of the display 10. Then, the process proceeds to step 138, it is determined whether the vehicle has moved by a predetermined distance or more or the vehicle has rotated by a predetermined angle or more, and if there is movement or rotation of the vehicle, the process returns to step 106 to draw the priority display area. Repeat to update the bird's eye view road map.
When the movement and rotation of the vehicle are both less than or equal to the predetermined values, the routine proceeds to step 140, where it is determined whether or not the RAM 13 has a storage capacity for reading the road map data of the undrawn area of the display area ABCD. If the RAM 13 does not have the storage capacity, the process proceeds to step 148 to determine whether the vehicle has moved by a predetermined distance or more or the vehicle has rotated by a predetermined angle or more. If the vehicle has moved or rotated, the process returns to step 106 to give priority. The drawing process of the display area is repeated to update the bird's-eye view road map.

When the RAM 13 has a storage capacity enough to read the data of the undrawn area, the routine proceeds to step 142, where the road map data of the undrawn area in the non-priority display area 'is read. In the display example of this embodiment, since the non-priority display area 'is an undrawn area as shown in FIG. 12, the road map data of the area is read into the RAM 13. At this time,
It is conceivable to delete the data of the regional meshes M1 to M4 read in advance to draw the priority display area 'and the non-priority display area' to secure the storage capacity, but then, a slight movement or rotation of the vehicle. Since the data of the display priority area 'must be read again from time to time, the data of the area mesh including at least the display priority area' is not deleted in this embodiment. In step 144, the data of the undrawn area of the display area ABCD is converted into the bird's eye view road map data, and the following step 1
At 46, drawing is performed in the non-priority display area of the display 10. At this point, a bird's-eye view type road map is drawn on the entire display frame abcd of the display 10. Thereafter, the process proceeds to step 148, it is determined whether the vehicle has moved by a predetermined distance or more, or the vehicle has rotated by a predetermined angle or more, and if there is movement or rotation of the vehicle, the process returns to step 106 to draw the priority display area. Repeat to update the bird's eye view road map.

The display operation of the above embodiment when the traveling direction is greatly changed at the intersection will be described. It is now assumed that the vehicle turns a three-forked road at an acute angle as shown in FIG. 13 and proceeds to a destination. Just before the three-way road, read the data of the regional meshes M1 to M4 including the first display area,
Performs data conversion and drawing processing within the priority display area '.
Next, when the vehicle approaches the three-way road and rotates by a predetermined angle or more, data conversion and drawing processing of the non-priority display area 'of the first display area are not performed, and the viewpoint E and the line-of-sight direction φ are changed and the second display is performed. Start the data conversion and drawing processing of the area priority display area '. Since the data of the priority display area 'of the second display area has already been read into the memory, it is not necessary to read the data again. Subsequently, when the vehicle rotates by a predetermined angle or more and the direction change on the three-way road is completed, the viewpoint E and the line-of-sight direction φ are changed without performing the data conversion and the drawing processing of the non-priority display area 'of the second display area. Data conversion and drawing processing of the priority display area 'of the third display area are performed. Since the data of the priority display area 'of the third display area has already been read in the memory,
There is no need to read the data again.

After the priority display area 'of the third display area has been drawn, if there is no traveling over a predetermined distance and no direction change over a predetermined angle, it is necessary to draw a non-priority display area of the third display area'. . However, in the non-priority display area 'of the third display area, only the data of the non-priority display area' (data of the regional meshes M4 and M3) is read as shown in FIG. 14, and the data of the non-priority display area ' (Data of area meshes M5 and M6) are not read. Therefore, as described above, the data conversion of the non-priority display area 'and the drawing processing are performed for the time being, and if the movement and rotation of the vehicle are both smaller than a predetermined value thereafter, the unnecessary area meshes M1 and M2 in the memory are deleted. The data is erased, the road map data of the area meshes M5 and M6 is read again, and data conversion and drawing processing of the undrawn non-priority display area 'are performed. If the memory capacity is sufficiently large, the data in the regional meshes M1 and M2 need not be erased.

Thus, the display frame a of the display 10
In bcd, the priority display area for displaying the road map including the current location of the vehicle is set preferentially, and the road map of the area'corresponding to the priority display area of the plane road map is given priority over the other areas'. The data is read from the CD-ROM 8 to the RAM 13, converted into a bird's-eye view road map, and displayed on the display 10.
And draw a bird's-eye view type road map in the priority display area, and then convert the road map of the area'corresponding to the non-priority display area other than the priority display area of the planar road map to the bird's-eye view road map. Display 10
Since it is drawn on the road map, it is possible to preferentially display the road map in the area of high importance to the occupant. In addition, a priority display area divided by a horizontal line segment L of the display screen is set in the display frame abcd of the display 10, and the road map of the area'corresponding to the priority display area of the flat road map is set. The area of'the area corresponding to the priority display area from the display area ABCD on the flat road map is easily converted to the bird's-eye view road map by converting it into a bird's-eye view road map. It can be extracted by calculation and the drawing time of the bird's eye view can be shortened. After drawing a bird's-eye view road map in the priority display area, if the vehicle is detected to travel a predetermined distance or more, or if the vehicle rotates more than a predetermined angle, the bird's-eye view road to the non-priority display area is detected. The map is not drawn, and the bird's-eye view method road map in the priority display area is updated, so even if the vehicle moves at high speed or makes a large turn at an intersection, etc., it is an area of high importance to passengers. The road map of can be displayed in real time as the vehicle moves and rotates.

Although the above embodiment has shown an example in which the position of the viewpoint E and the gaze angle θ are constant, if the viewpoint position and the gaze angle are changed by the key 7 while the vehicle is running, FIG.
In steps 130, 138, and 148 of FIG. 10, the movement and rotation of the vehicle are determined, and it is determined whether or not the viewpoint position and the gaze angle are changed. If the viewpoint position and the gaze angle are changed by a predetermined value or more, the steps are performed. Returning to step 106, the drawing processing of the priority display area may be performed. Further, in the above-described embodiment, an example in which the current location of the vehicle is included in the display priority area is shown. However, when moving the cross line on the display screen to draw a bird's-eye view road map centering on an arbitrary point, The designated point may be included in the priority display area. Furthermore, an area near the viewpoint projection point E ′ may be set as the priority display area.

In the configuration of the above embodiment, the CD-R
The OM8 and the RAM 13 serve as storage means and the display 1
0 is a display unit, and CPU 4 is a drawing unit and a reading unit .
The RAM 13 constitutes a temporary storage means, the vehicle speed sensor 5 constitutes a distance detecting means, and the azimuth sensor 1 constitutes an azimuth detecting means.

[0031]

As described above, according to the invention of claim 1, the display screen of the display means for displaying one bird's-eye view road map is divided into upper and lower regions by the horizontal line segments, and
Set the area as the priority display area that preferentially displays the road map
And set the upper area as the non-priority display area ,
The road map in the area corresponding to the priority display area in the flat road map is converted into the bird's-eye view road map by giving priority to the non-priority display area, and the road map is drawn on the display means. The road map of the area can be displayed preferentially. According to the invention of claim 2, the display screen is set on a plane perpendicular to the line of sight of the plane road map looking down from the viewpoint above the vehicle rear, and the display area on the plane road map viewed from the viewpoint through the display screen is calculated. In addition, when converting the flat road map in this display area into a bird's-eye view road map and drawing it on the display screen, the display screen is divided into upper and lower areas.
Priority display to display the road map preferentially in the lower area
Area is set and the upper area is a non-priority display area
And calculate the priority display area on the flat road map viewed through the priority display area of the display screen, and convert the flat road map in this priority display area to the bird's-eye view road map by giving priority to the non-priority display area. Since it is drawn in the priority display area of the display screen, it is possible to preferentially display the road map in the area of high importance to the occupant. Claim 3
According to the invention, since the priority display area is the area including the current position of the vehicle, it is possible to preferentially display the road map around the current position of the vehicle, which is highly important for the occupants. According to the invention of claim 4, since the priority display area is an area including an arbitrary point, the road map around the arbitrary point can be preferentially displayed. According to the invention of claim 5, since the priority display area is an area close to the point where the viewpoint of the bird's-eye view is projected on the flat road map, the road map near the viewpoint projection point, which is highly important for the occupant, is preferentially displayed. can do. According to the invention of claim 6, since the priority display area is the area divided by the horizontal line segments of the display screen, the data of the area corresponding to the priority display area is displayed from the display area on the planar road map. It can be extracted by simple calculation, and the drawing time of the bird's-eye view can be shortened. According to the invention of claim 7, after the bird's-eye view road map is drawn in the priority display area of the display screen, the non-priority display area on the planar road map seen through the non-priority display area in the display screen is calculated. ,
Since the plane road map in this non-priority display area is converted into a bird's-eye view road map and drawn in the non-priority display area on the display screen, the road map in the area of high importance to the occupants should be displayed preferentially. You can According to the invention of claim 8, after the bird's-eye view road map is drawn in the priority display area of the display screen, whether the traveling of the vehicle over a predetermined distance or more is detected,
Or, when the rotation of the vehicle over a predetermined angle is detected, the bird's-eye view road map is not drawn in the non-priority display area,
The priority display area on the flat road map is calculated, the flat road map in the priority display area is converted to a bird's-eye view road map, and the bird's-eye view road map in the priority display area on the display screen is updated. Even when the vehicle is moved or the direction is greatly changed at an intersection or the like, it is possible to display the road map in an area of high importance to the passengers in real time as the vehicle moves and rotates. According to the invention of claim 9, the display screen is set on a plane perpendicular to the line of sight of the plane road map looking down from the viewpoint behind the vehicle, and the display area on the plane road map viewed from the viewpoint through the display screen is calculated. At the same time, the plane road map of the area mesh unit including the plane road map of this display area is read out from the storage means and stored in the temporary storage means, and within the display area of the plan view road maps stored in the temporary storage means. When converting the flat road map of to the bird's-eye view road map and drawing it on the display screen, the display screen is divided into upper and lower regions by horizontal line segments, and
Set the area as the priority display area that displays the road map with priority.
In addition, the upper area is set as a non-priority display area, the priority display area on the flat road map viewed through the priority display area of the display screen is calculated, and the area of the flat road map stored in the temporary storage means is calculated. Since the plane road map in the priority display area of the above is converted into the bird's-eye view road map in preference to the non-priority display area and drawn in the priority display area of the display screen, the temporary storage means is provided to reduce the cost of the device. Even if the storage capacity of is reduced, it is possible to preferentially display the road map in an area of high importance to the occupant. Claim 10
According to the invention, after the bird's-eye view road map is drawn in the priority display area of the display screen, the non-priority display area on the planar road map seen through the non-priority display area in the display screen is calculated and temporarily stored. Since the plane road map in the non-priority display area of the plane road map stored in the means is converted into the bird's-eye view road map, and the converted bird's-eye view road map is drawn in the non-priority display area of the display screen. It is possible to preferentially display a road map in an area of high importance to the occupants. According to the invention of claim 11, when only a part of the planar road map corresponding to the non-priority display area is read out to the temporary storage means, a part of the read planar road map is a bird's-eye view road map. Since the converted bird's-eye view road map is drawn in the non-priority display area of the display screen, it is possible to display the road map in the area of high importance to the passengers preferentially and It is possible to draw a bird's-eye view road map in most areas in a short time. According to the invention of claim 12, after the bird's-eye view road map is drawn in the priority display area of the display screen, the traveling of the vehicle over a predetermined distance or the rotation of the vehicle over a predetermined angle is detected. And, the bird's-eye view road map is not drawn for the non-priority display area, the priority display area on the plane road map is calculated, the plane road map in the priority display area is converted to the bird's-eye view road map, and the priority display on the display screen is performed. Since the bird's-eye view road map of the area is updated, even if the vehicle moves at high speed or makes a large turn at an intersection, the road map in the area of high importance to the occupants is accompanied by the movement and rotation of the vehicle. Can be displayed in real time.

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

FIG. 4 is an X′Y ′ coordinate system obtained by translating the XY two-dimensional plane map coordinate system shown in FIG. 3 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. 5 is a diagram showing a relationship between a viewpoint E and a display frame abcd of a display.

[FIG. 6] 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. 7 is a diagram showing a relationship between an example of division of a priority display area of a display and a display area on a planar road map.

FIG. 8 is a flowchart showing a road map display program of one embodiment.

9 is a flowchart showing a road map display program of one embodiment following FIG.

10 is a flowchart showing a road map display program of one embodiment following FIG. 9.

FIG. 11 is a diagram showing an example of reading a flat road map.

FIG. 12 is a diagram showing a relationship between a display area on a flat road map and a regional mesh.

FIG. 13 is a diagram for explaining the operation of the embodiment when the vehicle is largely turned.

FIG. 14 is a view for explaining the operation of the embodiment following FIG. 13 when the vehicle undergoes a major direction change.

[Explanation of symbols]

1 Direction sensor 2 A / D converter 3 Interface circuit 4 CPU 5 vehicle speed sensor 6 GPS receiver 7 keys 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 (56) Reference JP-A-5-46084 (JP, A) JP-A-5-118864 (JP, A) JP-A-2-244188 (JP, A) JP-A-5-101163 (JP , A) JP-A-1-263688 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G09B 29/00-29/14 G01C 21/00 G06T 17/50 G08G 1/0969

Claims (12)

(57) [Claims] 1. A storage unit for storing a flat road map, a display unit for displaying a bird's-eye view road map, and a display unit for converting the flat road map stored in the storage unit into a bird's-eye view road map. In a vehicle route guidance device having drawing means for drawing in the means, the display screen of the display means for displaying one bird's-eye view road map is divided into upper and lower regions by horizontal line segments, and
Set the area as the priority display area that displays the road map with priority.
And set the upper area as the non-priority display area.
Includes a range setting means, said drawing means, road bird's eye view mode giving priority to the priority display road map of the region corresponding to the region of the plane road map stored in said storage means to said non-priority display area A route guidance device for a vehicle, which is converted into a map and drawn on the display means. 2. A storage unit for storing a plane road map, and looking down the plane road map along a line of sight of a predetermined gaze angle from a viewpoint set at a predetermined position above the rear of the vehicle, on a plane perpendicular to the line of sight. A display area calculation means for setting a display screen of the display means and calculating a display area on the flat road map viewed through the display screen; and the display area calculation of the flat road map stored in the storage means. A map conversion means for converting the plane road map in the display area calculated by the means into a bird's-eye view road map; and a drawing means for drawing the bird's-eye view road map converted by the map conversion means on the display screen of the display means. In the vehicle route guidance device, the display screen of the display means is divided into upper and lower areas, and
Set the area as the priority display area that preferentially displays the road map
And set the upper area as the non-priority display area
An area setting means , the display area calculating means calculates a priority display area on a planar road map viewed through the priority display area in the display screen, and the map converting means is stored in the storage means. Among the existing flat road maps, the flat road map in the priority display area calculated by the display area calculating means is converted into the bird's-eye view road map by giving priority to the non-priority display area, and the drawing means is the map converting means. A route guidance device for a vehicle, wherein the bird's-eye view road map converted by the above is drawn in a priority display area of the display screen. 3. The vehicle route guiding apparatus according to claim 2, wherein the priority display area is an area including a current position of the vehicle. 4. The vehicle route guiding apparatus according to claim 2, wherein the priority display area is an area including an arbitrary point. 5. The vehicle route guiding apparatus according to claim 2, wherein the priority display area is an area near a point where a viewpoint of a bird's eye view is projected on a planar road map. apparatus. 6. The route guiding apparatus for a vehicle according to claim 2, wherein the priority display area is an area divided by a line segment in a horizontal direction of the display screen. A vehicle route guidance device. 7. The vehicle route guidance device according to claim 2, wherein after the bird's-eye view road map is drawn in the priority display area of the display screen, the display area calculation means Calculating a non-priority display area on the plane road map viewed through the non-priority display area in the display screen, wherein the map conversion means calculates the display area of the plane road map stored in the storage means. The plane road map in the non-priority display area calculated by the means is converted into a bird's-eye view road map, and the drawing means draws the bird's-eye view road map converted by the map converting means in the non-priority display area of the display screen. A vehicle route guidance device characterized by the above. 8. The route guiding apparatus for a vehicle according to claim 7, further comprising: a distance detecting means for detecting a traveling distance of the vehicle and an azimuth detecting means for detecting a traveling azimuth of the vehicle, wherein the priority display of the display screen is provided. After the bird's-eye view road map is drawn in the area, when the traveling of the vehicle of a predetermined distance or more is detected by the distance detecting means or the rotation of the vehicle of a predetermined angle or more is detected by the azimuth detecting means, A route guidance device for a vehicle, wherein the bird's-eye view road map of the priority display area is updated by the display area calculation means, the map conversion means, and the drawing means without drawing the bird's-eye view road map in the priority display area. 9. A storage unit for storing a flat road map in units of regional meshes, a temporary storage unit for temporarily storing the flat road map read from the storage unit, and a predetermined position above and behind the vehicle. From the set viewpoint, look down on the plane road map along the line of sight of a predetermined gaze angle, set the display screen of the display means on a plane perpendicular to the line of sight, and calculate the display area on the plane road map seen through the display screen. Display area calculating means for reading, a reading means for reading a planar road map of a regional mesh unit including a planar road map of the display area calculated by the display area calculating means from the storage means and storing the planar road map in the temporary storage means, Of the plane road maps stored in the temporary storage means, the plane road map in the display area calculated by the display area calculation means is converted into a bird's-eye view road map. And Figure converting means, in the vehicle navigation system that includes a drawing means for drawing the transformed bird's-eye view road map on a display screen of said display means by said map converting means, horizontal line of the display screen of the display unit Upper and lower areas
It is divided into areas and the lower area is displayed preferentially on the road map.
Set the priority display area, and give priority to the upper area
An area setting means for setting a display area, wherein the display area calculating means calculates a priority display area on a flat road map viewed through the priority display area in the display screen, and the map converting means Among the plane road maps stored in the storage means, the plane road map in the priority display area calculated by the display area calculation means is converted into the bird's-eye view road map by giving priority to the non-priority display area, and the drawing means Is a bird's-eye view road map converted by the map conversion means in a priority display area of the display screen. 10. The vehicle route guidance device according to claim 9, wherein after the bird's-eye view road map is drawn in the priority display area of the display screen, the display area calculation unit is a non-priority area in the display screen. The non-priority display area on the flat road map viewed through the display area is calculated, and the map conversion means selects the non-priority display area calculated by the display area calculation means of the flat road map stored in the temporary storage means. A vehicle characterized in that the flat road map in the priority display area is converted into a bird's-eye view road map, and the drawing means draws the bird's-eye view road map converted by the map converting means in a non-priority display area of the display screen. Route guidance device. 11. The route guidance apparatus for a vehicle according to claim 10, wherein the map conversion means reads only a part of the planar road map corresponding to the non-priority display area into the temporary storage means. Converts the part of the read flat road map into a bird's-eye view road map, and the drawing unit draws the bird's-eye view road map converted by the map converting unit in a non-priority display area of the display screen. A vehicle route guidance device characterized by the above. 12. The vehicle route guiding apparatus according to claim 10 or 11, further comprising: a distance detecting unit that detects a traveling distance of the vehicle; and an azimuth detecting unit that detects a traveling azimuth of the vehicle. After the bird's-eye view road map is drawn in the priority display area of the screen, the distance detection means detects the traveling of the vehicle over the predetermined distance or the direction detection means detects the rotation of the vehicle over the predetermined angle. And a bird's-eye view road map for the non-priority display area is not drawn, and the bird's-eye view road map of the priority display area is updated by the display area calculation means, the map conversion means and the drawing means. Vehicle route guidance device.