JP3428294B2 - Vehicle navigation system - 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 navigation system for displaying a route to a present location and a destination on a road map to guide an occupant.

[0002]

2. Description of the Related Art There is known a vehicle navigation device that guides an occupant by displaying a route to a destination and a current position of a vehicle on a bird's-eye view type road map (for example, Japanese Laid-Open Patent Publication No. Hei.
244188). A bird's eye view road map is
As shown in FIG. 12, a viewpoint B is set above a predetermined height of a point C which is a predetermined distance behind the current position A of the vehicle, and the direction of the vehicle is looked down from the viewpoint B along a line of sight of a predetermined looking down angle. In this case, the display area abcd of the plan view road map developed on the XY plane is perspective-transformed into a virtual screen (display screen) set perpendicular to the line of sight.

[0003]

By the way, lakes, parks, stadiums, schools, factories, etc. occupy certain areas on the map, and in the digital road map, the boundaries of these areas are polygons. Approximately, the polygon is registered by the coordinates of each vertex of the polygon and the connection order of each vertex starting from any vertex. Depending on the shape of the polygon, valley points may be included, and in this specification, the valley points are also referred to as vertices or simply points.
For example, as shown in FIG.
1 (coordinates XP11, YP11) to P16 (XP16, Y
P16) and the polygons are registered according to the connection order P11 → P12 → ... → P16 → P11 of the vertices starting from the vertex P11, and the position P1n (coordinate X1) at the substantially central position is registered.
n, Y1n) is registered with the polygon name “Concavo-convex manufacturing site”. In addition, as shown in FIG. 14, XX high school has a peak P2.
1 (coordinates XP21, YP21) to P24 (XP24, Y
P24) and the connection order P21 → P22 → ... → P24 → P21 of the vertices starting from the vertex P21, the polygon is registered, and the substantially central position P2n (coordinates XP2n,
The polygon name "○ × high school" is registered in YP2n).

[0004] When driving near such a concavo-convex factory and XX high school, it is displayed as shown in Fig. 15 in the plan view type navigation device and as shown in Fig. 16 in the bird's eye view type navigation device. It The unevenness manufacturing plant near the current location of the vehicle is displayed in the entire area on the plan view display screen and is partially displayed on the bird's eye view display screen. Here, the polygon name registration position P1 of the concavo-convex mill
Since n is in the display area of the plan view, the polygon name of “Concavo-convex Manufacturing” is displayed on the plan view display screen. However, since the polygon name registration position P1n of the concavo-convex mill is not in the bird's-eye view display area abcd, the “concavo-convex mill” is not displayed on the bird's-eye view display screen. Even if only a part of the polygon is displayed on the bird's-eye view display screen, if it is near the current position of the vehicle, the display area occupying the whole screen becomes considerably large. However, even if a polygon occupies a large area on the bird's-eye view display screen, if the polygon name registration position is not within the bird's-eye view display area, the polygon name "concavo-convex manufacturing site" is not displayed as shown in FIG. In such a case, the occupant must scroll the bird's-eye view display screen to the right until the polygon name is displayed. Normally, navigation devices prohibit scrolling while running, so
You have to stop and scroll to see the polygon name.

On the other hand, since the polygon name registration position of the XX high school far from the current location of the vehicle is in both the plan view and bird's eye view display areas, it is displayed on both display screens.
Although it is displayed in a large area on the plan view display screen, it is displayed in a small area on the bird's eye view display screen because it is far from the current location. However, since the polygon name registration position is within the bird's-eye view display area even though it is displayed in a small area on the bird's-eye view display screen, the polygon name "○ ×"
High school "is displayed. Polygon names far from the current location are less important as information, and the road map is displayed in a reduced size far away from the current location, so the display density of roads is high and all polygons of low importance are displayed. When it comes to things, road maps become more difficult to see.

An object of the present invention is to provide a vehicular navigation device which determines whether or not a polygon name is displayed based on the display area of the polygon.

[0007]

[Means for Solving the Problems] (1) The invention of claim 1 stores a plan view road map including polygon information, and a conversion unit for converting the plan view road map of the storage unit into a bird's-eye view road map. And a display means for displaying the bird's-eye view road map converted by the conversion means .
Calculate the display area of the gon and use that display area as a bird's-eye view
Correcting according to the distance from the projection point
The display means displays a polygon name for a polygon whose area calculated by the calculation means is equal to or larger than a predetermined value. Top view on road map
The area of the polygon to be calculated is calculated and the display area in the plan view
Is corrected according to the distance from the viewpoint projection point of the bird's-eye view
The display area of the polygon in the figure is calculated, and the polygon name is displayed for the polygon whose calculated display area is a predetermined value or more. (2) The vehicle navigation device according to claim 2 has a display
By the means, among the polygons whose names are displayed,
For polygons whose name registration position is outside the bird's eye view display area
The polygon at the position of the center of gravity of the polygon display area.
The name registration position is moved .

[0008]

(1) According to the invention of claim 1, the flat surface
Figure: Calculate the polygon display area on the road map and
The display area in the plan view is the distance from the viewpoint projection point in the bird's eye view
Correct the polygon display area in the bird's eye view according to
For polygons whose calculated display area is greater than or equal to a specified value
Since the polygon name is displayed, the name is displayed for polygons that are displayed in a bird's-eye view over a predetermined area, and the polygon name can be confirmed without stopping each time and scrolling the bird's-eye view display screen. In addition, since the name is not displayed for polygons that are far from the vehicle and smaller than the predetermined area, unnecessary names with low importance are not displayed, and roads in the distance and other information with high importance are visually recognized. It will be easier. Further, compared with the calculation method by coordinate conversion, the load of the arithmetic processing of the microcomputer is reduced and the drawing speed of the bird's-eye view is increased. (2) According to the invention of claim 2, for polygons whose names are displayed outside the bird's-eye view display area among polygons displaying names, the polygon name registration position is set at a position substantially at the center of gravity of the polygon display area. In addition to the effect of claim 1 described above, the polygon name can be displayed at an appropriate position in the polygon display area on the bird's-eye view display screen.

[0009]

DETAILED DESCRIPTION OF THE INVENTION

-First Embodiment of the Invention- FIG. 1 is a block diagram showing a configuration of the first embodiment.
The controller 1 is composed of a microcomputer and its peripheral parts, and executes a control program to be described later to perform perspective conversion of the plan view road map into a bird's-eye view road map and display the bird's-eye view road map and the optimum route to the vehicle's current location and destination. To do. A direction sensor 2, a distance sensor 3, a GPS receiver 4, a storage device 5, and an input device 6 are connected to the controller 1. The direction sensor 2 detects the traveling direction of the vehicle, and the distance sensor 3 detects the traveling distance of the vehicle. The GPS receiver 4 receives GPS signals from satellites and detects the current location, traveling direction, traveling speed, etc. of the vehicle. The storage device 5 is a device such as a CD-ROM for storing road map data in a plan view, and the input device 6 is a device for setting a destination or the like. The controller 1 is also connected to a display 7 for displaying a road map and character information, a speaker 8 for guiding by voice, and the like.

FIG. 2 is a flow chart showing the road map display processing of the bird's-eye view method of the first embodiment. 3 to 7 are diagrams for explaining a method of converting the polygon area on the plan view road map into the area on the bird's-eye view display screen.
In the first embodiment, the road map shown in FIG. 15 will be described as an example. When the navigation device is powered on, the controller 1 starts the process shown in FIG. In step 1, the bird's-eye view display area abcd on the plan view is calculated according to the bird's-eye view display principle shown in FIG. In step 2, the polygon data included in the bird's-eye view display area abcd is extracted according to the attribute of the registration data of the digital map. In the example shown in FIG. 15, the concave-convex manufacturing facility and the polygons of XX high school are extracted. In step 3, a polygon name registration position and a polygon registration name are extracted from the extracted polygon data. As shown in FIG. 13 and FIG. 14, the name registration position P1 is set in the polygon of the unevenness manufacturing plant.
n and the registered name "Concavo-convex mill" are extracted, and in the polygon of ○ × high school, the name registration position P2n and the registered name “○ × high school”
Is extracted.

In step 4, the area in the bird's eye view display area abcd for the extracted polygon is calculated.
Here, a method of calculating the area will be described. As shown in FIG. 3, the polygon side P13 is applied to the polygon of the unevenness manufacturing facility.
-P14, P14-P15 and the line segment ab of the bird's eye view display area
The area of the triangle formed by the intersection points ab1 and ab2 and the vertex P14 is calculated. First, intersections ab1 and ab2 between the polygon side and the line segment ab are obtained. As described above, since the connection order of the vertices is registered in the polygon data, it is possible to know which vertices each side forming the polygon connects. Therefore, the equation of the polygon side and the line segment ab is expressed by the parameter display, which polygon side intersects the line segment ab, and the intersection point is obtained. Intersection ab
When 1 and ab2 are calculated, a triangle (P14 → ab1 → ab) in the map display area abcd of the polygon of the unevenness manufacturing plant.
Calculate the area of 2) according to Heron's formula. Note that FIG.
As shown in, the line segment ab is polygon sides P12-P13, P
When intersecting with 15-P16, the area may be calculated by dividing into a plurality of triangles as shown in FIG. The method of calculating the area of the polygon cut out by the bird's eye view display area abcd is not limited to the above method, and for example, a method by image processing or the like can be used.

After the polygon area in the bird's-eye view display area on the plan view is calculated, in step 5, the display area when the polygon is displayed in the bird's-eye view is estimated. This estimation is performed by multiplying the polygon area in the bird's-eye view display area on the plan view by a correction value according to the distance from the viewpoint projection point C.
This correction value is set to be smaller as the distance from the viewpoint projection point C becomes longer. In this embodiment,
As shown in FIG. 6, regions C to R1, R1 to R2, R2 to R3, R3 to R4, and R according to the distance from the viewpoint projection point C.
4 to are set, and the correction value is determined for each area according to the distance from the viewpoint projection point C. Of course, a continuous correction value may be set according to the distance from the viewpoint projection point C. The polygon area in the bird's-eye view display area on the plan view is multiplied by the correction value of the area in which the polygon is located to estimate the polygon display area on the bird's-eye view display screen. In addition, the polygon display area in the bird's-eye view display area calculated on the plan view road map is corrected by a correction value according to the distance from the viewpoint projection point C without estimating the polygon display area on the bird's-eye view display screen. Alternatively, the polygon display area on the plan view road map may be coordinate-converted into the display area on the bird's-eye view display screen to accurately obtain the area.

In the following step 6, it is judged whether or not the estimated value of the polygon display area on the bird's-eye view display screen is greater than or equal to a predetermined value, and if the estimated value of the polygon display area is greater than or equal to the predetermined value, the process proceeds to step 7. If not, proceed to step 8. This predetermined value is a reference area for determining whether or not to display the polygon name on the bird's-eye view display screen, and an appropriate value is set in advance for the display screen area of the display 7 corresponding to the virtual screen of FIG. Set. When the polygon display area on the bird's eye view display screen is equal to or larger than the predetermined value, it is determined in step 7 whether the polygon name registration position is within the bird's eye view display area abcd. If the polygon name registration position is within the bird's-eye view display area, the polygon name registered at that position should be displayed, so the process proceeds to step 8. If the name registration position is not within the bird's-eye view display region, the process proceeds to step 9. .

If the polygon display area on the bird's-eye view display screen is smaller than a predetermined value, it is determined that the polygon name need not be displayed, and in step 8, the polygon name is masked and excluded. On the other hand, if the polygon display area on the bird's-eye view display screen is greater than or equal to a predetermined value and the polygon name registration position is not within the bird's-eye view display area, it is necessary to display the polygon name, but it cannot be displayed as it is. At 9, the polygon name registration position is offset into the polygon display area on the bird's eye view display screen, and the name of the polygon is displayed in the polygon display area on the bird's eye view display screen. In the example shown in FIG. 3, the polygon name registration position P1n outside the bird's eye view display area is offset to substantially the center of gravity P1n ′ of the display areas P14, ab1, ab2 as shown in FIG. Further, as shown in FIG. 4, even if the polygon name registration position P1n is in the bird's-eye view display area, but it is not in the position of the center of gravity of the polygon display area, as shown in FIG. 5, the display areas P13, P14, P15, ab1, a
It is offset to approximately the center of gravity P1n ′ of b2.

In step 10, the road map data in the bird's-eye view display area abcd on the plan view is coordinate-converted into a bird's-eye view. At this time, the polygon name registration position offset in the polygon display area of the bird's-eye view is also coordinate-converted to the position in the bird's-eye view. In the following step 11, the display 7
In addition to displaying the bird's-eye view road map, the polygon name is displayed at the position of the center of gravity of a polygon having a predetermined area or more, as shown in FIG. In the example shown in FIG. 8, the name is displayed at the position of the center of gravity of the display area for the polygon of the unevenness factory having the area equal to or larger than the predetermined value, but for the XX high school whose area is smaller than the predetermined value. The polygon name is not displayed. The display position of the polygon name is not limited to the barycentric position, and may be, for example, substantially the center of the polygon display area in the bird's-eye view. The above processing for polygons is performed for all polygons in the bird's-eye view display area. In step 12, if the power of the apparatus is turned off, the process is ended. If not, the process returns to step 1 to repeat the above process.

In this way, the polygon area in the bird's-eye view display area is calculated on the plan view road map, and the polygon display area on the bird's-eye view display screen is estimated by correcting it with the correction value according to the distance from the viewpoint projection point. Then, the polygon name registered for the polygon whose estimated area is equal to or larger than a predetermined value is displayed. As for the display position of the polygon name, for polygons whose polygon name registration position is outside the bird's-eye view display area, the name registration position is moved to approximately the center of gravity of the polygon display area on the bird's-eye view display screen. As a result, for polygons that are displayed in a bird's eye view with a predetermined area or more, names are displayed at appropriate positions in the polygon display area, and the polygon names can be confirmed without stopping each time and scrolling the bird's eye view display screen. In addition, since the name is not displayed for polygons that are far from the vehicle and smaller than the predetermined area, unnecessary names with low importance are not displayed, and roads in the distance and other information with high importance are visually recognized. It will be easier. In addition, the polygon display area obtained on the plan view is corrected according to the distance from the viewpoint projection point to estimate the polygon display area on the bird's-eye view display screen regardless of the calculation method by coordinate conversion. The calculation processing load is reduced, and the bird's-eye view drawing speed is increased.

-Second Embodiment of the Invention- In the above-described first embodiment, the case of displaying the bird's-eye view road map has been described as an example, but the second embodiment of the case where the plan view road map is displayed. The form will be described. The configuration of the second embodiment is the same as the configuration of the first embodiment shown in FIG. 1, and the description thereof will be omitted. FIG. 9 is a flowchart showing the road map display processing of the plan view method of the second embodiment. In the second embodiment, the road map shown in FIG. 10 will be described as an example. The controller 1 starts the process shown in FIG. 9 when the navigation device is powered on. In step 21, the map display area abcd in the plan view is calculated as shown in FIG. In step 22, according to the attribute of the registration data of the digital map,
The polygon data included in the display area abcd is extracted. In the example shown in FIG. 10, the polygons of the uneven manufacturing facility are extracted. In step 23, a polygon name registration position and a polygon registration name are extracted from the extracted polygon data. As shown in FIG. 10, the name registration position P1n and the registered name “concavo-convex shop” are extracted from the polygon of the concavo-convex shop.

In step 24, the area in the display area abcd for the extracted polygon is calculated by the method described above. In step 25, it is determined whether the polygon display area is equal to or larger than a predetermined value. This predetermined value is a reference area for determining whether or not to display the polygon name on the display screen, and an appropriate value is set in advance for the area of the display screen of the display 7. If the display area of the polygon is equal to or larger than the predetermined value, the process proceeds to step 26, and if not, the process proceeds to step 27. If the polygon display area on the plan view display screen is equal to or larger than the predetermined value, it is determined in step 26 whether or not the polygon name registration position is within the display area abcd. If the polygon name registration position is within the road map display area, the polygon name registered at that position may be displayed, so the process proceeds to step 29. If the name registration position is not within the road map display area, step 28 is performed. Go to.

If the polygon display area on the plan view display screen is smaller than the predetermined value, it is determined that the polygon name need not be displayed, and in step 27, the polygon name is masked and excluded from the display target. On the other hand, if the polygon display area on the plan view display screen is equal to or larger than the predetermined value and the polygon name registration position is not within the display area, the polygon name needs to be displayed but cannot be displayed as it is. The polygon name registration position is offset into the polygon display area of the plan view display screen, and the name of the polygon is displayed in the polygon area of the plan view display screen. In the example shown in FIG. 10, the polygon name registration position P1n outside the road map display area is offset to approximately the center of gravity P1n ′ of the polygon display area. When the polygon name registration position is within the road map display area but not at its center of gravity position, the polygon name registration position is offset to almost the center of gravity position of the display area.

In step 29, the plan view road map is displayed on the display 7 and, as shown in FIG. 11, the polygon name is displayed at the position of the center of gravity of a polygon having a predetermined area or more. In the example shown in FIG. 11, with respect to polygons having a predetermined area or larger, the name is displayed at the position of the center of gravity of the display area. The display position of the polygon name is not limited to the barycentric position, and may be, for example, substantially the center of the polygon display area in the plan view. The above processing for polygons is performed for all polygons in the road map display area. In step 30, if the power of the device is turned off, the process is ended. If not, the process returns to step 21 to repeat the above-mentioned process.

In this way, the polygon area in the road map display area is calculated, and the registered polygon name is displayed for the polygon having a display area of a predetermined value or more. Regarding the polygon name display position, for polygons whose polygon name registration position is outside the road map display region, the name registration position is moved to approximately the center of gravity of the polygon display region on the display screen. As a result, for polygons displayed in a predetermined area or more, names are displayed at appropriate positions within the polygon display area, and the polygon names can be confirmed without stopping and scrolling the display screen. In addition, since the name is not displayed for polygons smaller than the predetermined area, unnecessary names with low importance are not displayed, and roads and other information with high importance are easily visible.

In the configuration of the above embodiment, the storage device 5 constitutes storage means, the controller 1 constitutes conversion means and calculation means, and the controller 1 and display 8 constitute display means.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment.

FIG. 2 is a flowchart showing road map display processing of a bird's-eye view method according to the first embodiment.

FIG. 3 is a diagram showing a method of converting a polygon area on a plan view road map into an area on a bird's-eye view display screen.

FIG. 4 is a diagram showing a method of converting a polygon area on a plan view road map into an area on a bird's-eye view display screen.

FIG. 5 is a diagram illustrating an offset method of a polygon name registration position.

FIG. 6 is a diagram illustrating a correction value for converting a polygon area on a plan view road map into an area on a bird's-eye view display screen.

FIG. 7 is a diagram illustrating an offset method of a polygon name registration position.

FIG. 8 is a diagram showing a display example of a bird's-eye view road map according to the first embodiment.

FIG. 9 is a flowchart showing a road map display process of the second embodiment.

FIG. 10 is a diagram showing a display area on a flat road map.

FIG. 11 is a diagram showing a display example of a plan view road map according to the second embodiment.

FIG. 12 is a diagram illustrating a display principle of a bird's eye view.

FIG. 13 is a diagram showing an example of a polygon.

FIG. 14 is a diagram showing an example of a polygon.

FIG. 15 is a diagram showing a bird's-eye view display area on a flat road map.

FIG. 16 is a diagram showing a display example of a conventional bird's-eye view road map.

[Explanation of symbols]

1 controller 2 direction sensor 3 distance sensor 4 GPS receiver 5 storage devices 6 Input device 7 display 8 speakers

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Claims (2)

(57) [Claims] 1. A storage unit that stores a plan view road map including polygon information, a conversion unit that converts the plan view road map of the storage unit into a bird's-eye view road map, and a bird's-eye view road map converted by the conversion unit. In a vehicular navigation device having display means for displaying, a polygon display area on the plan view road map is calculated.
The display area to the distance from the viewpoint projection point of the bird's eye view
Compensation is performed accordingly to calculate the polygon display area in the bird's-eye view , and the display means displays the polygon name for a polygon whose calculated area by the calculation means is a predetermined value or more. A vehicle navigation device characterized by: 2. The vehicle navigation device according to claim 1, wherein the display means is a polygon that displays the name.
Polygon whose Rigoon name registration position is outside the bird's eye view display area
, The polygon is displayed at the center of gravity of the display area.
A vehicular navigation device that moves the Ligo name registration position .