JPH04313786A - On-vehicle information display controller - Google Patents

Abstract

PURPOSE:To facilitate the path distance calculation by constituting what is called a navigation system so that information is read out of an inscribed storage medium and a circumscribed storage medium stored by different coordinate constitutions, respectively, and they can be superposed and displayed on a display device. CONSTITUTION:Additional information stored in a circumscribed storage medium 9 is subjected to coordinate transformation to a secondary mesh normalized coordinate from longitude/latitude coordinates, therefore, road map information is read out of an inscribed storage medium 1 and displayed on a display device 8, and also, the additional information subjected to coordinate transformation can be superposed and displayed. In such a way, a function of the navigation system can be extended and improved by an application program of the circumscribed storage medium 9. Also, since an actual distance normalized coordinate unit is derived, the path calculation is facilitated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle information display control device.

0002

[Prior Art] A navigation system installed in a vehicle that displays traffic information, etc. stores road map information on a CD-ROM, etc., on expressways, general national roads, etc. nationwide.
Memorize information on major local roads, general prefectural roads, etc.
Accuracy can be achieved by reading out information from each area as needed and displaying it on a display device such as a CRT, and by matching the vehicle position detected by a direction sensor or mileage sensor with a road map for route calculation. The vehicle position is calculated and displayed on the road map. here,
When displaying road map information on a display device, it is more convenient to display as much traffic-related facility information as possible, for example, facility names along the road. For this reason, in addition to the above road map information, the CD-ROM contains stations, airports, interchanges, etc.
It also contains a lot of information on transportation-related facilities such as road repair points.

0003

[Problems to be Solved by the Invention] However, conventional navigation systems are closed, dedicated systems, and cannot be connected to other storage media, resulting in the problem that functions cannot be expanded or applied. For example, when displaying information about roads on a display device, the information is limited to the content stored in advance in a standard internal storage medium, and other content cannot be displayed in an overlapping manner. In other words, in addition to road map information, the CD-ROM that is standard equipment in the navigation system records many public transportation-related facilities nationwide as road-related information, but it also records private transportation-related facilities, For example, information about gas stations, parking lots, restaurants, etc. at tourist spots is not stored. Such private additional information is stored separately from the navigation system in the form of a so-called application program.
It is possible to store it in a D-ROM and provide it. If this CD-ROM can be replaced with the standard CD-ROM and installed in the navigation system, this additional information can be displayed on the display device.

However, conventional navigation systems are based on one CD-ROM drive, and multiple CD-ROM drives are used.
Since there is no function to share and overlay data from the D-ROM, it has not been possible to display additional private information about roads stored in the CD-ROM over the road map data. In other words, when displaying a road map read from a standard CD-ROM in a conventional navigation system, it was not possible to read and display additional information from the CD-ROM that stored an application program. Of course, if both additional information and road map information are stored in a CD-ROM provided as an application program, they can be displayed in a superimposed manner. However, if this is done, the standard CD-ROM and the road map information will be duplicated, which is wasteful.

[0005] Therefore, a navigation system is equipped as a standard with a CD-ROM that stores road map information as an internal storage medium, and a CD-ROM that stores additional information as a removable external storage medium. It would be very rational if information could be shared and displayed overlappingly on a display device. However, there is a problem that the coordinate configuration of the CD-ROM provided as an application program and the coordinate configuration of the standard CD-ROM do not necessarily match, and therefore cannot be displayed as is. For example, with the standard CD-ROM, 2
It is generally stored as the next mesh normalized coordinates, but C
In the D-ROM, the coordinates may be stored in latitude and longitude coordinates.

[0006] Here, the secondary mesh normalized coordinates are obtained from the primary standard area and the secondary standard area as follows.

[0007] First, the primary standard area is created by dividing the area of the country vertically and horizontally by 1 degree meridian and 40 minute latitude, and the mesh code of the primary standard area is the latitude value at the bottom left of the area. It is expressed as a four-digit number axay, which is a combination of a two-digit number ax obtained by multiplying by 3/2, and a two-digit number ay obtained by subtracting 100 from the longitude value. For example, if the latitude value at the bottom left of the primary standard area is 35 degrees 20 minutes and the longitude value is 135 degrees, then (35 + 1/3
)×3/2=53, 135-100=35, so
The mesh code of the primary standard area is axay=5335.

[0008] Next, the secondary standard area is created by dividing the primary standard area into 8 equal parts vertically and horizontally, dividing it into sections of 7 minutes and 30 seconds in the longitude direction and 5 minutes in the latitude direction, and the mesh code of the secondary standard area is as follows. ,
In the primary standard area divided into 8 equal parts vertically and horizontally, facing north with the lower left as a reference,
A number from 0 to 7 is assigned to each direction facing east, and expressed as a two-digit number bxby that is combined in order of the vertical direction and the horizontal direction. For example, if the secondary standard area is the third standard area northward and seventh eastward from the lower left of the primary standard area, the mesh code bxby of the secondary standard area is 26.

Furthermore, in the secondary standard area, the upper left corner of the area is (0,10000) and the upper right corner of the area is (10000,10000).
000), the lower left corner of the section is (0,0), the lower right corner of the section is (1
0000, 0) and the coordinate value is the normalized coordinate value (cx, cy). And the first mesh code a
xay, quadratic mesh code bxby, normalized coordinates (c
axay, bxby, cx,
Let cy be the quadratic mesh normalized coordinates. Therefore, in the above example case, the normalized coordinate values (cx, cy) are (3
000, 7000), the quadratic mesh normalized coordinates are 5335, 26, 3000, 7000.

On the other hand, latitude and longitude are based on longitude lines, which are great circles that pass through the earth's poles and surround the earth, and latitude lines that are perpendicular to the longitude lines on the earth's surface. It is indicated in seconds, latitude, minutes, and seconds. With CD-ROMs having such different coordinate configurations, it is not possible to share the information and display it on a display device in an overlapping manner.

Furthermore, in the secondary mesh normalized coordinate system, since the spherical surface of the earth is divided by longitude and latitude, the primary standard area is not strictly a square but a trapezoid. Furthermore, if the primary standard area has the same longitude but different latitude, the length in the longitude and latitude directions will differ. For this reason, there is a problem that calculating the distance between two points is complicated.

The present invention has been made in view of the above-mentioned prior art, and reads information from storage media having different coordinate configurations, applies coordinate transformation to one of them, and superimposes the information on a display device. It is an object of the present invention to provide an on-vehicle information display control device that can display information on the vehicle and easily calculate the distance between two points.

[0013]

[Means for Solving the Problems] The configuration of the present invention for achieving the above object is to store road map information consisting of a plurality of map elements into
An inscribed storage medium stored by the next mesh normalized coordinates,
a drawing display control circuit that draws in an image memory based on information based on secondary mesh normalized coordinates; a removable circumscribed storage medium that stores additional information consisting of at least one transportation-related facility using latitude and longitude coordinates; The application program stored in the circumscribed storage medium is interpreted to convert the additional information read from the circumscribed storage medium from the latitude and latitude coordinates to the quadratic mesh normalized coordinates, and the an interpreter that instructs the drawing display control circuit to draw additional information superimposed on the image memory and calculates an actual distance corresponding to each normalized coordinate unit of the quadratic mesh normalized coordinates; and the image memory. The present invention is characterized by comprising a display device that displays the road map information and the additional information arbitrarily read from the road map information.

【Example】

The present invention will be explained in detail below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. As shown in the figure, the in-vehicle information display control device of this embodiment constitutes a so-called navigation system. That is, this navigation system includes a CD-ROM 1 as an internal storage medium, a map information processing circuit 2, an interpreter 3, a GDC 4, an image memory 5, a drawing display control circuit 6,
It is composed of a color information table 7 and a CRT 8 which is a display device, and a CD-ROM 9 which is a external storage medium can be freely attached and detached.

[0015] Here, the CD-ROM, which is an internal storage medium,
1 is standard equipment in the navigation system and stores road map information consisting of map elements such as nationwide expressways, general national roads, major local roads, general prefectural roads, etc., and also stores station, airport, etc.
It also stores a lot of information on public transportation-related facilities such as interchanges and road repair points. Since many public transportation-related facilities are inseparable from map elements, they will be included and expressed as map elements below. Also, this CD-ROM
1 is used by being attached to a CD-ROM drive, but the CD-ROM drive is not shown here. Further, this CD-ROM 1 may be of a so-called built-in type that cannot be replaced, or may be of a replaceable type. CD-ROM, which is an internal storage medium
In No. 1, the road map information is stored as quadratic mesh normalized coordinates. For example, 5335, 26,
They are stored as 3000, 7000, and so on.

The map information processing circuit 2 reads road map information consisting of map elements from the CD-ROM 1, which is an internal storage medium, and also maps these pieces of information and color identifiers in correspondence with each other.
Output to DC4. The relationship between map elements and color identifiers is set in advance in the color information table 7.

On the other hand, the CD-ROM 9 which is an external storage medium
An application program containing private additional information not stored in the CD-ROM 1, which is an internal storage medium, is stored in the . For example, transportation-related facilities such as gas stations and parking lots at specific tourist spots, or transportation-related facilities covering restaurants in the metropolitan area, etc. are stored. In addition, the specific contents of traffic-related facilities are not limited to those directly related to traffic, but also those indirectly related, such as roads that are prone to freezing, traffic jams, acquaintances' homes, etc. It is sufficient if it is at least one or more of the following. Since such additional information is required by the driver's request, the CD-ROM 9, which is an external storage medium, is a CD-ROM.
It is used by being detachably attached to the drive. In the CD-ROM 9, which is a circumscribed storage medium, the above-mentioned additional information is stored in the form of latitude and longitude coordinates.

The application program on the CD-ROM 9 also includes a program for mutually converting the latitude and latitude coordinates stored in the CD-ROM 9 and the quadratic mesh normalized coordinates, and is interpreted by the interpreter 3. executed. When the program is read into the interpreter 3 and executed, the latitude and latitude coordinates and the quadratic mesh normalized coordinates are mutually converted as follows.

Longitude [seconds] = (Longitude primary mesh code ax + 100) x 60 x 60 + Longitude secondary mesh code bx x 7.5 x 60 + x direction normalized coordinate cx x 7
．． 5 x 60 latitude [seconds] = (Latitude direction primary mesh code ay x (2
/3)) x 60 x 60 + latitudinal secondary mesh code b
y x 5 x 60 + y direction normalized coordinates cy x 5 x 60

00
20 The additional information thus converted into quadratic mesh normalized coordinates is input to the GDC 4.

The GDC 4 is software that controls the drawing display control circuit 6 to perform drawing processing.
It is called Display Controller. The GDC 4 receives road map information from the map information processing circuit 2 and additional information from the interpreter 3 in the form of secondary mesh normalized coordinates, and converts the secondary mesh normalized coordinates into internal normalized coordinates as follows. Convert to (X, Y).

X=cx+bx×10000+ax×10000×8Y
=cy+by×10000+ay×10000×8

0
[023] However, ax, ay: Mesh code of the primary standard area bx, by: Mesh code of the secondary standard area cx, cy:
Normalized coordinate value The internal normalized coordinates (X, Y) converted in this way are 1
These are coordinates expressed in the X-Y plane using unit normalized coordinates as the origin, with the next mesh code 0, the second mesh code 0, and the normalized coordinate values (0, 0) as the origin.

The image memory 5 is also called VRAM, and is capable of setting one or more arbitrary areas as a drawing area at an arbitrary scale according to specifications of an application program. When two or more drawing areas are set in the image memory 5, the content to be displayed next on the CRT 8 can be quickly created, which has the advantage of speeding up screen switching. For example, the drawing area is 288 dots horizontally and 248 dots vertically.
It is preferable to use dots or 144 horizontally and 124 vertically. In addition, as for the scale, for example, 1/1.6 million, 1/400,000,
1/200,000, 1/100,000, 1/25,000, 1/1.25
It's good to have 10,000. Further, depending on the number of drawing dots and the scale, the range developed in the drawing area is divided into four primary standard areas, 1/4 primary standard area, secondary standard area, and tertiary standard area. Table 1 summarizes these.

[0025]

[Table 1]

Here, in Table 1, the corresponding internal normalized values are the internal normalized coordinates (X,
This is a value used to find the number of dots proportional to Y). For example, in order to draw a map element in a drawing area, as shown in the flowchart of Figure 2, first the center point of the drawing area and the position of the map element to be drawn (hereinafter referred to as the specified point) are It is necessary to convert each to normalized coordinates and find the difference between the center point of the drawing area and the specified point. Then, based on the internal normalized coordinate difference in the X and Y directions, a dot difference is determined according to Equation 1 according to the scale code shown in Table 1.

[0027]

[Math 1]

The dot difference in the X and Y directions obtained in this way is added to the coordinates of the center point of the drawing area, and a map element is drawn. The map elements to be drawn include not only the road map information stored in the CD-ROM 1 but also additional information stored in the CD-ROM 9. For this reason, public transportation-related facilities such as expressways, general national roads, major local roads, and general prefectural roads are drawn, as well as private transportation-related facilities, such as gas stations and parking spots at tourist spots. Car parks, restaurants, etc. will be drawn.

Furthermore, the application program stored in the CD-ROM 9 includes a program for calculating the actual distance corresponding to each normalized coordinate unit of the quadratic mesh normalized coordinates. When this is read into interpreter 3 and executed, C
Distances of map elements etc. displayed on RT8 can be calculated. This program uses the relationship between the top side A, bottom side B, and height C of the primary standard area of a plurality of representative points across the country shown in Table 2 and their primary mesh code. Incidentally, the relationship between the top side A, the bottom side B, and the height C in the primary standard section is shown in FIG.

[0030]

[Table 2]

As described above, the primary standard area is not a rectangle but a trapezoid, strictly speaking, and calculating the distance as it is is complicated. Further, the primary standard sections have the same shape when they are at the same latitude, but the lengths of the top side A, the bottom side B, and the height C are different when the latitudes are different even if they are at the same longitude. For this reason, the distance is calculated by approximating a rectangle.

First, as shown in the flowchart of FIG. 6, a map table shown in Table 2 is created in advance, and the relationship between the top side A, bottom side B, and height C of the primary standard area and its primary mesh code is determined. I'll ask for it. Next, it is determined whether there is a primary standard area in Table 1 that has the same latitude as the primary standard area to which the specified point belongs. This is done by checking whether the first two digits of the primary mesh code match. If there is a primary standard area in Table 1 that has the same latitude as the primary standard area to which the designated point belongs, the upper side A of that primary standard area
, base B, and height C are approximated to a rectangle according to Equation 2.

[0033]

[Math 2]

However, as shown in FIG. 7, X and Y are the horizontal and vertical lengths of the rectangle, and y and y0 are the normalized heights when converting a trapezoid into a rectangle. In addition, if there is no one in Table 1 that has the same latitude as the primary standard area to which the specified point belongs, it is approximated to a rectangle according to Equation 3.

[0035]

[Math 3]

However, as shown in FIG. 8, A1, B1, C
1, A2, B2, and C2 are the top, bottom, and height of each primary standard area in the north and south that are closest to the primary standard area to which the designated point belongs. The horizontal and vertical lengths X and Y of the primary standard area as a rectangle approximated in this way are converted to the distance of one drawing dot shown in Table 1, and this is further divided by the corresponding internal normalized value. Then, calculate the distance per internal normalized coordinate unit. In this way, the distance per internal normalized coordinate unit is determined, and the distance between two points on the CRT 8 is calculated.

The CRT 8 is designed to display the information drawn in the drawing area of the image memory 5 according to the color identifier of the color information table 7, and the area that can be displayed on the CRT 8 is the drawing area of the image memory 5. The range is slightly narrower than that of .

In the navigation system of this embodiment having the above configuration, the application program stored in the CD-ROM 9, which is the external storage medium, uses the road map information stored in the CD-ROM 1, which is the internal storage medium. Thus, various types of information can be displayed on the display device 8 in an overlapping manner. That is, as shown in FIGS. 3 and 4, when the application program stored in the CD-ROM 9, which is the external storage medium, is interpreted and executed by the interpreter 3, first, the application program stored in the latitude and longitude coordinates from the CD-ROM 9 is Additional information is read. Next, the drawing display control circuit 6 is controlled by the GDC 4 to convert the latitude and latitude coordinates into secondary mesh normalized coordinates, and further convert the secondary mesh normalized coordinates into coordinates in the image memory and store the coordinates in the image memory 5.
to draw. The contents drawn in the drawing area of the image memory 5 will be displayed on the CRT 8. Here, CRT
8, road map information read out from the CD-ROM 1, which is an internal storage medium, is displayed in advance. For this reason,
On the CRT 8, road maps and public transportation-related facilities read out from the CD-ROM 1 are displayed.
The private additional information read from the D-ROM 9 will be displayed after coordinate transformation. For example, CD-RO
On the road map read from M1 and displayed on the CRT 8, a mark ○ indicating a bank and a mark △ indicating a shrine can be displayed superimposed. When displaying this information, it is convenient to display numerical values indicating the longitude and latitude coordinates of banks and shrines.

Furthermore, when calculating the distance of a route arbitrarily designated by the driver and displaying it on the CRT 8, the process is performed according to the flowchart shown in FIG. First of all,
When starting calculation of route distance, the coordinate number counter is reset to 0, and the route distance is reset to 0. Next, the distance per internal normalized coordinate unit in the X and Y directions is calculated using the procedure described above. After this, by moving the cursor to the desired position and pressing the specified switch,
Read the coordinates of that cursor position. The coordinates thus read are converted into quadratic mesh normalized coordinates and stored in memory. In order to calculate the distance, it is necessary to input the positions of at least two points, and if there are three or more points, the distance is calculated according to the input order, and this is repeated multiple times. If the score is less than 2 points, an error message is displayed on the CRT 8. After entering the desired coordinates, the first stored coordinates are read from memory and set as the starting point, then the stored coordinates are read from memory and set as the ending point, and the internal normalized coordinate difference between the starting point and the end of the war is calculated. is calculated, and this value is multiplied by the distance per normalized coordinate unit in each of the X and Y directions. The distance in the X and Y directions is determined by the Pythagorean theorem to determine the distance between the two points, and the distance is accumulated to the route distance. If there are three or more target points, the above procedure is repeated multiple times to accumulate the route distance. When the route distance has been accumulated, the result is displayed on the CRT 8.

In the above embodiment, a plurality of pieces of information are displayed in an overlapping manner on the CRT 8, but depending on the type of application program and the purpose of use, it may be unnecessary to display some of the map elements. For example, it may not be necessary to display expressways or narrow streets. Therefore, in such a case, it is convenient for the drawing display control circuit 6 to omit drawing such map elements or to make them less conspicuous in accordance with instructions from the application program. Further, in the above embodiments, a large capacity, low cost and compact CD-ROM is used as the storage medium, but the present invention is not limited to this, and other storage media may be used.
For example, a hard disk, floppy disk, etc. may be used. The map information processing circuit 2, interpreter 3, etc. can also be realized as a circuit incorporating software.

[0041]

Effects of the Invention As described above in detail based on the embodiments, the present invention provides a method for converting additional information stored in a circumscribed storage medium from latitude and latitude coordinates to quadratic mesh normalized coordinates in a so-called navigation system. Since the conversion has been performed, the road map information in the internal storage medium can be retrieved from the application program in the external storage medium, and traffic-related facilities indicating private additional information can be superimposed and displayed on top of the road map information. In other words, according to the present invention, it is possible to expand and improve the functionality of the navigation system using the application program on the external storage medium. Furthermore, since the actual distance per unit of normalized coordinates is determined, there is an advantage that route calculation is facilitated.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an in-vehicle information display control device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a process of calculating a dot difference within a drawing area based on internal normalized coordinates.

FIG. 3 is an explanatory diagram conceptually showing how information read from two CD-ROMs is displayed in an overlapping manner on a display device.

FIG. 4 is a flowchart showing a process of coordinate transformation from latitude and latitude coordinates to quadratic mesh normalized coordinates.

FIG. 5 is an explanatory diagram showing the relationship between the top side, bottom side, and height of primary mesh normalized coordinates.

FIG. 6 is a flowchart showing a process of approximating primary mesh normalized coordinates from a trapezoid to a rectangle.

FIG. 7 is an explanatory diagram showing approximation from a trapezoid to a rectangle when there is something corresponding to the primary standard area shown in Table 2.

8 is an explanatory diagram showing approximation from a trapezoid to a rectangle when there is nothing corresponding to the primary standard area shown in Table 2. FIG.

FIG. 9 is a flowchart showing a process of calculating and displaying the distance of a specified route.

[Explanation of symbols]

1 CD-ROM (internal storage medium) 2 Map information processing circuit 3 Interpreter 4 GDC 5 Image memory 6 Drawing display control circuit 7 Color information table 8 CRT 9 CD-ROM (external storage medium)

Claims (1)

[Claims] 1. An inscribed storage medium that stores road map information consisting of a plurality of map elements using secondary mesh normalized coordinates, and a drawing display control circuit that draws images in an image memory based on the information based on the secondary mesh normalized coordinates. a removable external storage medium storing additional information consisting of at least one or more transportation-related facilities in latitude and longitude coordinates; and an application program stored in the external storage medium that is interpreted and read from the external storage medium. the drawing display control circuit to convert the additional information from the latitude and latitude coordinates into secondary mesh normalized coordinates, and to draw the additional information converted into the secondary mesh normalized coordinates in an overlapping manner on the image memory; an interpreter that commands and calculates an actual distance corresponding to each normalized coordinate unit of the quadratic mesh normalized coordinates; and a display device that displays the road map information and the additional information arbitrarily read from the image memory. An in-vehicle information display control device comprising: