JPH06100471B2 - Map display method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a map display method of an automobile navigation system (hereinafter referred to as a navigation system) for displaying a guide route to a destination, and particularly to a vehicle The present invention relates to a map display method capable of automatically displaying the most detailed map including a current position and a destination.

<Prior Art> Map data storage means for storing map data, such as a CD
-There is a car navigation system that uses ROM. Such a car navigation system is a CD
-In addition to storing a large amount of map data in the ROM, a display device and a position measuring device for measuring the current position of the vehicle are provided, and the map data corresponding to the vehicle position is read from the CD-ROM and drawn on the display screen. , And draw a location cursor showing the current position of the vehicle on the map,
The cursor is moved on the map according to the movement of the vehicle.

By the way, the map data stored in the CD-ROM has a hierarchical structure of several stages from a wide range of map data to a detailed diagram in which a predetermined area is described in detail, as shown in FIG. In FIG. 5, A, B, and C are map data for each layer, and map data B _{1 to} B ₄ are map data in which each region of the map data C is divided into, for example, 4 and described in detail. map data a ₁ to a ₄ is a map data further described in detail each region by dividing 4 for example an area of the map data B _4. These map data A, B, C display a map with a predetermined degree of detail on the screen of the display device. In addition, a map image based on n × m (for example, 3 × 3) map data is stored in the video RAM of the display device, and a range (called a window) for reading the map image from the video RAM by the scroll function is shifted. By doing 2
It is possible to display an area over one or more map data on the display screen. In FIG. 5, x indicates the destination and Δ indicates the position of the own vehicle.

Conventionally, when a map with a scale that can display the destination x and the vehicle position △ in the same display is required to confirm the guide route, etc., the target map can be operated by key operation to enlarge or reduce the map. Had been selected. At this time, generally the map is enlarged
The process of reduction does not allow continuous enlargement / reduction between layers as in the case of zooming of a camera or the like, and the map data A, B, and B corresponding to the respective enlargement / reduction as shown in FIG. This is done by reading C from the CD-ROM.

For example, when a map including the vehicle position Δ is displayed by the map data A ₁ (see FIG. 5 (a)), if data about the destination x is input, the navigation system causes the map data of each layer (for example, The position of the destination x on B ₁ , C) shown in FIGS. 5B and 5C is recognized. After that, when it is desired to display the destination x and the vehicle position Δ simultaneously on the display screen in order to confirm the destination x already input, the following operation is performed. That is, by operating the reduction key, the map data A ₁ is switched to A ₁ → B ₄ → C, and a wider area including the area of the map data A ₁ is sequentially displayed on the screen. Thus, the map data C
To display the destination x and the vehicle position Δ at the same time (5th
(Refer to the display screen shown in FIG. 7C.) Then, even if the operator scrolls the window even if the scale of the map data B is reduced, it is determined that the destination X and the vehicle position Δ can be displayed at the same time. then, again reads map data B ₄ by expanding the key operation, sets a window D to destination × and vehicle position scroll △ enters the single screen, which has been displayed (see FIG. 6 ).

<Problems to be Solved by the Invention> However, in the conventional map display method as described above, the operator himself / herself has to search for a map capable of simultaneously displaying the destination X and the vehicle position Δ by the enlargement / reduction key operation. Therefore, for example, even if the vehicle position Δ approaches the destination × and a more detailed map can be displayed than the map currently being displayed, if the operator does not notice, a rough wide area map continues to be displayed, There is a problem in that the optimal map cannot be selected for use, and the operation is complicated and difficult to use.

In view of the above, an object of the present invention is to provide a map display method for an automobile navigation system that can automatically display the most detailed map including the current position of the vehicle and the destination.

<Means for Solving the Problem> According to the present invention, the above-mentioned problem is a memory for storing a map image corresponding to map data for n × m screens and a memory for storing a map image for one screen corresponding to a vehicle position. Based on the distance, a means for sequentially cutting out and displaying the destination, a means for requesting the destination and the vehicle position to be displayed at the same time, a means for calculating the distance in the longitude direction and the latitude direction between the destination and the vehicle position, and A means capable of displaying the destination and the vehicle position on one screen and determining the scale of the map with the most detailed description, and the destination on the map image corresponding to the map data of n × m screens of the scale. This is achieved by means of setting a window so as to include the vehicle position, and cutting out a map image in the window from the memory and displaying it.

<Operation> A map image corresponding to n × m screen map data is stored in the memory, and one screen map image corresponding to the vehicle position is sequentially cut out from the memory and displayed, and the destination and the vehicle position are also displayed. When there is a request to display at the same time, the distance between the destination and the vehicle position in the longitude direction and the latitude direction can be calculated, and the destination and the vehicle position can be displayed on one screen based on the distance. The most detailed map scale is determined, a window is set to include the destination and the vehicle position on the map image corresponding to the map data of n × m screens of the scale, and the map image in the window is stored in the memory. Cut out and display.

<Embodiment> FIG. 1 shows an automobile navigation system capable of realizing the present invention.
It is a block configuration diagram of a system.

In the figure, 1 is a CD-ROM which serves as a map data storage means, and the map data stored in this CD-ROM 1 has a hierarchical structure of map data A, B and C as shown in FIG. There is. A sensor 2 for position detection includes a geomagnetic sensor for detecting an absolute azimuth, a vehicle speed sensor for detecting a traveling distance, a transmission sensor for detecting forward and backward movements, and a steering sensor for detecting an azimuth. 3 is an operation unit, which is a CD
-Operation keys such as ROM access and map search, scroll key 3a for moving the window range up, down, left and right, destination setting key 3b for inputting data of destination x, destination x and vehicle position Δ by the present invention. It has various keys such as a destination display key 3c for displaying in one screen. 4 is CD-
A map data memory for storing n × m (for example, 3 × 3) map data read from the ROM 1 is a display processor 5 ′ for generating a map image from the map data.
Is a video RAM for storing map images corresponding to n.times.m map data, and 6 is a display unit composed of a liquid crystal, a cathode ray tube and the like. Reference numeral 7 denotes a processing device for controlling the entire navigation system, which is based on the data of the destination x input by the own vehicle position calculating means 7a for calculating the own vehicle position Δ from the data of the sensor 2 and the destination setting key 3b. Destination recognition means 7b for determining the position on the map, actual distance calculation means 7c for calculating the distance in the longitude direction and the latitude direction between the destination x and the vehicle position Δ by operating the destination display key 3c The scale x and the vehicle position Δ can be displayed on one screen of the display unit 6, and the scale selecting means 7d for determining the scale of the map with the most detailed description, and the destination x and the self on the map drawn by the scale 7d. It has window setting means 7e for setting the range (window) of the map for one screen for displaying the vehicle position Δ.

When the scale is selected by the scale selecting means 7d, the processor (not shown) of the processing device 7 outputs the map data (the car position is present on the central screen) for n × m screens of the scale to the CD-RO.
It is read from M and stored in the map data memory 4. The display processor 5 generates a map image for n × m screens from the map data and stores it in the video RAM 5 ′.

The window setting means 7e determines a map range (window position) for one screen in which the destination and the vehicle position can be displayed, and instructs the display processor 5. The display processor 5 cuts out a one-screen map image corresponding to the window position from the video RAM 5 ', inputs it to the display unit 6, and displays it.

FIG. 2 is a diagram for explaining the method of calculating the actual distance between the destination and the vehicle position according to the present invention.

In the figure, 11 is a display screen, that is, a window, and the X axis and the Y axis represent the longitude and latitude on the display screen 11, respectively. When the map display of the present invention is instructed by the destination display key 3c, the actual distance calculating means 7c causes the destination x and the own vehicle position Δ obtained from the destination recognizing means 7a and the own vehicle position calculating means 7b. A longitude difference and a latitude difference between both points are obtained from the latitude, and a distance r between both points, a longitude direction distance e, and a latitude direction distance n are calculated based on the longitude difference and the latitude difference and the size of the earth. The distances r, e, and n are constantly updated to the latest data as the vehicle moves or time elapses, and are stored in a memory (not shown).

The scale selection means 7d selects the most detailed map of the scale capable of displaying the destination x and the vehicle position Δ on the screen based on the distance e in the longitude direction and the distance n in the latitude direction. When selecting, the correspondence table of the distance d _{1 in the} longitude direction and the maximum scale of the map data which can display the distance on one screen, and the distance d _{2 in the} latitude direction and the map data which can display the distance on the one screen are displayed. A correspondence table with the maximum scale is created in advance, a scale s ₁ obtained from the distance e in the longitude direction and a scale s ₂ obtained from the distance n in the latitude direction are obtained, and map data having a smaller scale is selected. For example the map data A described above in FIG. 5, B, if there is C, the scale of d 1 ₌ 1km or less if it maps data A, scale d 1 ₌ 1~10km if map data B, d 1 ₌ 10~ 100km if the scale of the map data C, also, if _{d 2} = 0.8km following scale of the map data a, the scale of _{d 2} = _0.8~8km if map data B, _d 2 = 8~80km if map data C A correspondence table is created in the same manner as the scale, and if d ₁ = 15 km and d ₂ = 4 km, the map data of C is selected from s ₁ <s ₂ .

FIG. 3 is a diagram for explaining the window setting method according to the present invention.

In the figure, x ₁ and x ₂ are longitudes slightly inside the display screen 11, that is, the window, and y ₁ and y ₂ are latitudes slightly inside the display screen 11.

Window setting means 7e, on the map of the selected scale,
The window is set so that the destination x is located on the line of the quadrangle formed by the above-mentioned longitude / latitude x ₁ , x ₂ , y ₁ , y ₂ and the destination is included in the quadrangle.

FIG. 4 is a flow chart of processing of the present invention. Destination setting key
When the destination x is set by 3b, the longitude / latitude of the destination x is stored in the built-in memory (step 101), and thereafter the navigation processing up to the destination x is performed. In this state, when the map display of the present invention is instructed by the destination display key 3c (step 102), the longitude / latitude of the vehicle position Δ calculated by the vehicle position calculating means 7a is fetched (step 103), The actual distance calculating means 7c calculates a distance e in the longitude direction, a distance n in the latitude direction, and a distance r between the destination x and the vehicle position Δ (step 104).

The scale selection means 7d is capable of displaying the destination x and the vehicle position Δ on one screen, and determines the scale of the map which is the most detailed description. As a result, the processor (not shown) of the processing device 7 can store the map data of the determined n × m screens on the CD.
-Read from ROM1 and store in map data memory 4.
The display processor 5 generates a map image for n × m screens from the map data and stores it in the video RAM 5 '(step 105). The window setting means 7e sets a window capable of displaying the destination x and the vehicle position Δ on the map for one screen drawn at the scale (step 106), and the display processor 5 displays the map image of the window as the video RA.
It is read from M4 and displayed on the display unit 6 (step 10
7).

Then, if the destination display is not cleared, step 103
Then, the subsequent processing is repeated (step 108). If the destination display is cleared, the enlarged map of only the vehicle position Δ is displayed and the navigation processing is continued.

<Effects of the Invention> According to the present invention, the distance between the destination and the vehicle position in the longitude direction and the latitude direction can be calculated, and the destination and the vehicle position can be displayed on one screen based on these distances. In addition, since the scale of the map with the most detailed description is determined and the destination and the own vehicle position are displayed on the map for one screen drawn at this scale, the current position and the purpose of the own vehicle are determined. You can automatically display the most detailed map including the area,
Effectively improves the operability of the system.

Further, according to the present invention, a window is set so that the destination and the vehicle position are included on the map image generated from the map data for n × m screens, and the image in the window is cut out and displayed. Therefore, one screen can be cut out across the map images for a plurality of screens, and as a result, the most detailed map image can be displayed.

[Brief description of drawings]

FIG. 1 shows an automobile navigation system that can realize the present invention.
FIG. 2 is a block diagram of the system, FIG. 2 is a diagram for explaining a method of calculating an actual distance between a destination and a vehicle position according to the present invention, and FIG. 3 is a diagram for explaining a window setting method according to the present invention. 4, FIG. 4 is a flow chart of processing of the present invention, FIG. 5 is a diagram for explaining a map enlarging / reducing operation, and FIG. 6 is a diagram for explaining a scrolling operation. 3b …… Destination setting key, 3c …… Destination display key, 6 …… Display unit, 7a …… Self-vehicle position calculation means, 7b …… Destination recognition means, 7c …… Actual distance calculation means, 7d …… Scale selection means, 7e …… Window setting means.

Claims (1)

[Claims] 1. A map display method for an automobile navigation system for displaying a destination and a current position of one's own vehicle on a map within one screen, wherein a map image corresponding to n × m screen map data is stored in a memory. When there is a request to display the map image for one screen corresponding to the position of the car by sequentially cutting out from the memory and displaying the destination and the car position at the same time,
The distance between the destination and the vehicle position in the longitude and latitude directions is calculated, the destination and the vehicle position can be displayed on one screen based on the distance, and the scale of the map with the most detailed description is determined. A window is set so as to include a destination and a vehicle position on a map image corresponding to map data of n × m screens of the reduced scale, and the map image in the window is cut out from a memory and displayed. Map display method for car navigation system.