JPH0821738A - On-vehicle navigation apparatus - Google Patents

Abstract

PURPOSE:To prevent a map form being scarcely seen due to many road names. CONSTITUTION:A map image plotter 12 reads map data around a vehicle position from a CD-ROM 1 on the basis of vehicle position data detected by a GPS receiver 2, and adds variable data GDD to road name data. An importance setter 20 sets variable data GDD indicating importance to display a road name to each road name depending upon whether it is a road existing within a predetermined range ahead of a vehicle in the advancing direction or not and the class of the road. The plotter 12 plots a map image including the vehicle position in a video RAM 13 by using the map data of a buffer memory 11, and plots, in this case, only one or more of the variable data GDD of the name. A vehicle position mark is plotted at the predetermined position of the RAM 13. The image of the RAM 13 is read by a video converter 14, converted into a predetermined video signal, output to a display unit 4, and displayed on screen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted navigation device, and particularly to reading map data around a vehicle position from a map data storage means and drawing a map image including a background around the vehicle position and a road name together with a vehicle position mark. The present invention relates to a vehicle-mounted navigation device that displays a screen on a display unit.

[0002]

2. Description of the Related Art A vehicle-mounted navigation device is a large-capacity storage device such as a CD-ROM for storing a large amount of map data.
It has a display device, a vehicle position detection device for detecting the current position of the vehicle, etc., reads out map data including the current position of the vehicle from the CD-ROM, draws a map image based on the map data, and displays it on the display screen. At the same time, the vehicle position mark (location cursor) is fixed at a fixed position on the display screen (for example, the center of the screen), the map image is scrolled according to the movement of the vehicle, and the map image is fixed on the screen. Is displayed so that you can see at a glance where the vehicle is currently traveling.

The map stored in the CD-ROM is divided into a longitude width and a latitude width of an appropriate size according to the scale level, and roads and the like are vertices (nodes) expressed in latitude and longitude.
It is indicated by the coordinate set of. The road is composed of two or more nodes connected to each other, and a part connecting the two nodes is called a link. Map data includes (1) road list, node table, intersection node list, map net consisting of intersection netlist, road layer for route search, and (2) roads, buildings, rivers, etc. displayed on map screen. A background layer for displaying, (3) city / town / village name, road name, character / symbol layer for displaying map symbols, and the like. The road name data of the character / symbol layer is composed of a character code string, display start position data, character size data, display color data and the like.

The road layer has a structure shown in FIG. The road list RDLT has a road type (0;
National road, 1; Expressway, 2; General road, 3; Other roads), the total number of nodes that make up the road, the positions of the nodes that make up the road on the node table NDTB, and the width to the next node (0 ; 1.5m or more and less than 2.5m, 1; 2.5m or more and 5.5m
Less than 2; 5.5 m or more and less than 11.0 m, 3; 11.0 m or more). Intersection node list C
The RLT is, for each intersection on the map, a set of positions on the node table NDTB of the other end node of the link (referred to as an intersection constituent node) that connects to the intersection. The node table NDTB is a list of all nodes on the map. Position information (longitude, latitude) for each node, an intersection identification flag indicating whether or not the node is an intersection, and if the intersection is an intersection, the node configuration node list is displayed. It is composed of a pointer or the like that points to the position and points to the position of the road to which the node belongs on the road list if it is not an intersection.

The intersection netlist CRNL is (1) intersection sequential number for each intersection node (2) map leaf number of the map including the intersection node (3) data unit code Above, intersection node ID (4) intersection constituent node Number (5) Sequential number of each adjacent intersection (6) Distance to each adjacent intersection (7) Road attributes (road type, width) to each adjacent intersection.

The on-vehicle navigation system has a route guidance function that searches for an optimal route, for example, that follows the shortest distance from the departure point to the destination point, displays the guidance route on the screen, and guides the driver. Some of them have some, and in actual driving, the guide route is displayed in bold with a specific color so that it can be distinguished from other roads, or a guide mark that moves along the guide route in front of the vehicle position mark is displayed. The driver can easily reach the destination.

[0007]

When there are few roads such as in the suburbs, displaying all the road names does not pose any problem, but if the road names are all displayed in urban areas where the road density is high, the road names will not be displayed. There was a problem that the screen became full and overlapped with each other, making it difficult to see the map. In view of the above, an object of the present invention is to provide a vehicle-mounted navigation device that can prevent a map from being difficult to see with many road names.

[0008]

According to the present invention, there is provided a map data storage means for storing map data,
Using the vehicle position detection means for detecting the vehicle position and the vehicle direction and the map data read from the map data storage means, a map image including the background around the vehicle position and the road name is drawn together with the vehicle position mark and displayed on the display means. In a vehicle-mounted navigation device equipped with a map image drawing means, a setting means for setting the importance of displaying the road name according to the positional relationship between the vehicle and the road and the type of the road is provided, and the map image drawing means is fixed by the setting means. This is achieved by drawing road names for roads for which the above-mentioned importance levels have been set.

[0009]

According to the present invention, the degree of importance of displaying the road name is set according to the positional relationship between the vehicle and the road and the type of the road, and the road name is drawn for the road having the certain degree of importance or more.
In this way, roads that are important to the driver, such as roads that are ahead of the vehicle in the direction of travel and major roads such as national roads and highways, are displayed so that they are not inconvenient. Road names of roads of low importance such as different roads and roads that are not main roads can be omitted to prevent the map from being hard to see.

Further, map data storage means for storing map data, vehicle position detection means for detecting a vehicle position and a vehicle direction, and guide route data storage means for storing guide route data connecting a departure place and a destination. Using the map data read from the map data storage means and the guide route data stored in the guide route data storage means, a map image including the background around the vehicle position, the guide route, and the road name is drawn together with the vehicle position mark on the display means. In a vehicle-mounted navigation device equipped with a map image drawing means for displaying on a screen, the importance of displaying a road name depending on the positional relationship between the vehicle and the road, the type of the road, and whether or not the road matches a part of the guide route. Setting means for setting is provided, and the map image drawing means draws a road name for a road whose importance is set to a certain level or higher by the setting means.
As a result, roads that are ahead of the vehicle in the direction of travel, major roads such as expressways, and important roads for the driver such as guide routes are displayed with road names to prevent inconvenience. Different roads, non-main roads,
It is possible to prevent the map from being hard to see by omitting the display of road names of roads of low importance such as roads that are not guide routes.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of a vehicle-mounted navigation device according to an embodiment of the present invention. In the figure, 1 is a CD-ROM storing map data composed of road layers, background layers, character / symbol layers, etc., 2 is a GPS receiver for detecting the vehicle position and vehicle direction by satellite navigation, and 3 is a map scroll. Operation unit equipped with 4 direction keys for operation, route guidance mode setting / release key, destination setting key, etc.
Is a display device that displays a map image including the current position of the vehicle together with a vehicle position mark, a guide route, and the like.

Reference numeral 10 denotes a navigation controller having a microcomputer configuration. In the navigation mode, a map image around the vehicle position is drawn together with the vehicle position mark using the map data stored in the CD-ROM 1 and displayed on the display device 4 to display the map. In the scroll mode, the map image around the cursor position is drawn together with the cursor mark and displayed on the display device 4. In the route guidance mode, the map image around the vehicle position is drawn together with the guide route and the vehicle position mark and displayed on the display device 4. .

Of the navigation controller 10, 1
1 is a buffer memory for storing map data read from the CD-ROM 1, 12 is a navigation mode,
Draw a map image with the vehicle position as the center with the north facing upward using the map data including the vehicle position and the vehicle position mark, and in the map scroll mode, the cursor position (longitude, A map image with north as the center (latitude) is drawn with the cursor mark, and in the route guidance mode, a map image with north as the center with the vehicle position facing upwards is drawn with the vehicle position mark and the guide route. It is a drawing unit. This map image drawing unit 12 is a buffer memory 11 from the CD-ROM 1.
When you read the map data to the
As shown in (4), four variable data GDA to GDD are added.

Reference numeral 13 is a video RAM for storing the image drawn by the map image drawing unit 12, and 14 is a video RAM.
An image conversion unit that reads out the image stored in 13 and converts it into a predetermined image signal and outputs it to the display device 4.

Reference numeral 15 denotes a cursor position calculation unit, which is first detected by the GPS receiver 2 in the map scroll mode (immediately after the route guidance mode setting key is pressed, the navigation controller 10 automatically sets the map scroll mode). Initially set the vehicle position as the cursor position,
After that, the map image drawing unit 1 calculates the cursor position that continuously changes from the initial setting position according to the map scroll operation.
2, and the map image is scrolled by rewriting the map image in the video RAM 13 so that the cursor position is always at the center (in the map scroll mode,
A cursor mark is drawn by the map image drawing unit 12 at the center of the map image).

When a destination setting key is pressed after the cursor mark at the center of the screen is set to the destination by scrolling the map, the vehicle position 16 detected by the GPS receiver 2 at that point is the departure point, Departure / destination setting unit that sets the cursor position as the destination, 17 is the shortest optimal route connecting the departure and destination using the intersection netlist in the map data when the departure and destination are set By a horizontal search method, 18 is a guide route memory that stores, as guide route data, a node sequence that forms an optimum route connecting a starting point to a destination, 19 is an initial setting immediately after power-on, And a mode setting unit for performing a predetermined mode setting when operating the route guidance mode setting / release key on the operation unit 3.

Reference numeral 20 denotes a positional relationship between the vehicle and the road, road type,
The map data read from the CD-ROM 1 to the buffer memory 11 in the navigation mode and the route guidance mode is an importance degree setting unit that sets the degree of importance for displaying the road name depending on whether or not the road is a guidance route. Variable data GD for each road name data every time the vehicle position changes
Change and set A to GDD. Specifically, the road layer corresponding to the road name existing in the character / symbol layer (see FIG. 8)
The road defined by the above is specified, and it exists within a certain range in front of the traveling direction of the vehicle, as shown in FIG. 3, from the node sequence forming the road, the vehicle position and the vehicle direction detected by the GPS receiver 2. The variable data GDA is set to 1 when it is a road, and 0 when it does not exist. Also, the variable data GDB is set to 1 when the type of road is a national road, set to 2 when it is an expressway, and set to 0 otherwise. Finally, if the current route guidance mode is not set, the variable data GDC is set to 0. If the route guidance mode is set, GDC is set to 2 when the road matches a part of the guidance route, and 0 when the road does not match a part of the guidance route. Set. Then, the sum of GDA to GDC is calculated and set in the variable data GDD as a value indicating the importance of displaying the road name.

When the road name is drawn in the navigation mode and the route guidance mode, the map image drawing unit 12 draws road names only for roads with variable data GDD above a certain level, and road names for roads with a GDD below a certain level. Omit the drawing. Specifically, GD in navigation mode
Road names are drawn only for roads with D of 1 or more, and road names are drawn only for roads of GDD of 2 or more in the route guidance mode.

4 to 6 are flow charts showing the operation of the navigation controller 10, and FIG. 7 is an explanatory view of an example of screen display, which will be described below with reference to these figures. When the navigation processing power source is turned on, the GPS receiver 2 periodically detects the vehicle position and the vehicle direction by satellite navigation. On the other hand, after the navigation controller 10 is powered on, the mode setting unit 19 initially sets the navigation mode (step 101 in FIG. 4). The map image drawing unit 12 is the GPS receiver 2
Enter vehicle position data and vehicle direction data from CD-
Map data around the vehicle position is read from the ROM 1 into the buffer memory 11 (steps 102 and 103). At this time, variable data GDA to GDD are added to each road name data (see FIG. 2). Next, the importance level setting unit 20 identifies the road defined in the road layer corresponding to the road name existing in the character / symbol layer read in the buffer memory 11, and determines the node sequence and the vehicle position that form the road. As shown in FIG. 3, GDA is set to 1 when the road exists within a certain range ahead of the vehicle traveling direction based on the vehicle direction, and to 0 when the road does not exist. Further, GDB is set to 1 when the type of road is national road, 2 when it is an expressway, and 0 otherwise. Finally, since it is not the current route guidance mode, 0 is set to GDC. Then, the sum of GDA to GDC is set in GDD (step 104).

Next, the map image drawing unit 12 draws a map image with north facing upward centering on the vehicle position in the video RAM 13 using the map data read out to the buffer memory 11 (step 105). Specifically, using the data of the background layer in the map data, a background image of the road, buildings, rivers, etc. with the north facing upward with the vehicle position as the center is drawn in the video RAM 13, and the data of the character / symbol layer is used. Draw the names of cities, towns and villages, road names, and map symbols at the relevant locations on the background image. At this time, as for the road name, only the road having GDD of 1 or more is drawn. Then, the map image drawing unit 12 draws a vehicle position mark in which the vehicle azimuth direction is oriented at the center of the map image (step 106). Video RAM1
The image drawn in FIG. 3 is read by the video conversion unit 14, converted into a predetermined video signal, output to the display device 4, and displayed on the screen (step 107, FIG. 7).
(See (1)).

On the screen, road names are displayed only for roads, highways, and national roads existing in the forward direction of the vehicle. Therefore, even when driving in an urban area, the screen may be full of road names or the roads may overlap. The map will not be hard to see. In addition, roads that are important to the driver, such as roads, highways, and national roads existing in the forward direction of the vehicle are not inconvenient because the road names are displayed.

After step 107, the navigation controller 10 checks whether the guide route mode setting / releasing key is pressed (step 108). If NO, the map image drawing section 12 sends the vehicle position data from the GPS receiver 2 to the vehicle position data. Enter vehicle direction data (step 10)
9). Then, it is checked that the vehicle position has changed (step 110). If it has not changed, the process proceeds to step 108, and if it has changed, the process from step 103 onward is repeated. When the vehicle continues traveling without the driver pressing the guide route mode setting / release key, the map image on the screen scrolls with the movement of the vehicle with the vehicle position mark as the center. During this time, road names are displayed on the screen only for roads, highways, and national roads that are present in the forward direction of the vehicle.

After that, when the driver wants to travel by receiving route guidance from the current position to a certain destination, he / she presses the route guidance mode setting / release key. Then, the mode setting unit 19
Automatically sets the map scroll mode (step 10
8, step 201 in FIG. 5). In the map scroll mode, the cursor position calculation unit 15 initializes the vehicle position at that time as the cursor position (step 202),
The map image drawing unit 12 draws a map image centered on the cursor position in the video RAM 13 and draws a cursor mark at the center (steps 203 and 204). At this time, all the road names included in the map image area of the video RAM 13 are drawn regardless of the value of the variable data GDD. Video ram
The image 13 is read by the video converter 14, converted into a predetermined video signal, and output to the display device 4,
The screen is displayed (step 205).

In this state, when the driver performs a map scroll operation to search for a destination on the map image, the cursor position calculation unit 15 calculates the continuously changing cursor position,
The map image drawing unit 12 reads the map data around the cursor position from the CD-ROM 1 to the buffer memory 11 and redraws the map image centered on the cursor position together with the cursor mark using the read map data (step 205 to step 205). 207, 203-204) In the map scroll mode, all road names are drawn. Video ram
The image drawn on 13 is read by the video converter 14, converted into a predetermined video signal, output to the display device 4, and displayed on the screen (step 205). As a result, the map image on the screen is scrolled according to the map scrolling operation with the cursor mark at the center.

When the destination setting key is pressed when the cursor mark reaches the desired destination, the departure point / destination setting section 16 determines the vehicle position detected by the GPS receiver 2 at that time as the departure point, The cursor position is set as the destination (steps 209 and 210). When the starting point and the destination are set, the optimum route searching unit 17 reads the map data of the range including the starting point and the destination from the CD-ROM 1 into the buffer memory 11, and uses the intersection netlist to set the route between the starting point and the destination. The shortest optimal route connecting to is searched by simulation calculation such as horizontal search method or Dijkstra method. Then, the node sequence forming the searched guide route is stored in the guide route memory 18 as guide route data (step 211).

When the route guidance processing optimum route search is completed, the mode setting unit 19 sets the route guidance mode (step 212). When in the route guidance mode, first, the map image drawing unit 12 causes the GPS receiver 2
Vehicle position data and vehicle azimuth data are input (step 301 in FIG. 6), and map data including the vehicle position is stored on the CD-
The data is read from the ROM 1 to the buffer memory 11 (step 302). At this time, the road name data is variable data GDA.
~ Add GDD (see Figure 2). Next, the importance level setting unit 20 identifies the road defined in the road layer corresponding to the road name existing in the character / symbol layer read in the buffer memory 11, and determines the node sequence and the vehicle position that form the road. Based on the vehicle direction, GDA is set to 1 when a road exists within a certain range ahead of the vehicle traveling direction, and 0 is set when the road does not exist. Further, GDB is set to 1 when the type of road is national road, 2 when it is an expressway, and 0 otherwise. Finally, since the current route guidance mode is set, GDC is set to 2 when the road matches a part of the guidance route by referring to the guidance route data stored in the route guidance memory 18, and 0 when the road does not match a part of the guidance route. To do. Then, the sum of GDA to GDC is set in GDD (step 303).

Next, the map image drawing unit 12 uses the map data read out to the buffer memory 11 to draw a map image with north facing upward centering on the vehicle position in the video RAM 13 together with the guide route (step 304). Specifically, using the data of the background layer in the map data, the background image of the road, buildings, rivers, etc. with the north facing upward centering on the vehicle position is drawn in the video RAM 13 and stored in the guide route memory 18. Video RAM1 of the guide route data
Read the data in the map drawing area of No. 3, draw a guide route that is emphasized in a color different from other roads, and use the data of the character / symbol layer to display the name of the municipality in the corresponding place on the background image. , Draw road names, map symbols. At this time, the road name is drawn only for roads having GDD of 2 or more. Then, the map image drawing unit 12 draws a vehicle position mark in which the vehicle azimuth direction is oriented at the center of the map image (step 305). The image drawn in the video RAM 13 is read by the video conversion unit 14, converted into a predetermined video signal, output to the display device 4, and displayed on the screen (step 306, see FIG. 7 (2)).

Since the road names are displayed on the screen only for the guide route, the expressway, and the national road existing in the forward direction of the vehicle, the screen may be full of road names or the roads may overlap even when driving in the city area. And the map will not be hard to see. Also, roads that are important to the driver, such as guide routes, highways, and national roads existing in the forward direction of the vehicle, are not inconvenient because the road names are displayed.

After step 306, the navigation controller 10 checks whether the guide route mode setting / releasing key has been pressed (step 307). If NO, the map image drawing unit 12 sends the vehicle position data from the GPS receiver 2 to the vehicle position data. Enter vehicle heading data (step 30)
8). Then, it is checked that the vehicle position has changed (step 309). If it has not changed, the process proceeds to step 307, and if it has changed, the process from step 302 onward is repeated again. When the driver continues to drive the vehicle without pressing the guide route mode setting / release key, the map image on the screen scrolls with the guide route along with the movement of the vehicle while centering the vehicle position mark. During this period, road names are displayed only on the guide route and highways on the screen.

When the vehicle reaches the destination and the driver presses the route guidance mode setting / release key, the mode setting unit 19 releases the route guidance mode and returns to the original navigation mode (YES in step 307, Step 101 in FIG. 4).

In the above embodiment, the road name of the road having a GDD of 1 or more is drawn in the navigation mode, but the road name of the road having a GDD of 2 or more is drawn. Alternatively, in the route guidance mode, the road name of the road having a GDD of 2 or more is drawn, but the road name of the road having a GDD of 1 or more is drawn. May be.

[0032]

As described above, according to the present invention, the importance of displaying the road name is set according to the positional relationship between the vehicle and the road and the type of the road, and the road name is drawn for the road with the importance of a certain level or more. With this configuration, roads that are important to the driver such as roads ahead of the vehicle in the direction of travel and major roads such as national roads and highways are displayed to prevent inconvenience while displaying the road name. It is possible to prevent the road name from being difficult to see by omitting the display of road names of roads of low importance such as roads different from the direction and roads that are not main roads.

Further, map data storage means for storing map data, vehicle position detection means for detecting a vehicle position and a vehicle direction, and guide route data storage means for storing guide route data connecting a departure place and a destination. Using the map data read from the map data storage means and the guide route data stored in the guide route data storage means, a map image including the background around the vehicle position, the guide route, and the road name is drawn together with the vehicle position mark on the display means. In a vehicle-mounted navigation device equipped with a map image drawing means to be displayed on a screen, a setting is made to set the importance of displaying a road name depending on the positional relationship between the vehicle and the road, the type of the road, and whether or not the road matches the guide route. Means is provided, and the map image drawing means is configured to draw a road name for a road whose importance is set to a certain level or higher by the setting means. Roads that are in front of the direction of travel, major roads such as expressways, and important roads for the driver such as guide routes are displayed with road names to prevent inconvenience. Road names of roads of low importance such as roads that are not roads and roads that are not guide routes can be omitted to prevent the map from becoming difficult to see.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a vehicle-mounted navigation device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of variable data added to road name data.

FIG. 3 is an explanatory diagram of a method of setting variable data GDA.

FIG. 4 is a first diagram showing the operation of the navigation controller.
2 is a flowchart of.

FIG. 5 is a second diagram showing the operation of the navigation controller.
2 is a flowchart of.

FIG. 6 is a third view showing the operation of the navigation controller.
2 is a flowchart of.

FIG. 7 is an explanatory diagram showing a screen display example.

FIG. 8 is an explanatory diagram of data stored in a road layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CD-ROM 2 GPS receiver 3 Operation part 4 Display device 10 Navigation controller 11 Buffer memory 12 Map image drawing part 13 Video RAM 14 Video conversion part 15 Cursor position calculation part 16 Departure / destination setting part 17 Optimal route search part 18 guide route memory 19 mode setting unit 20 importance setting unit

Claims (2)

[Claims] 1. A map data storage means for storing map data, a vehicle position detection means for detecting a vehicle position and a vehicle direction, and a background around a vehicle position and a road name using map data read from the map data storage means. In a vehicle-mounted navigation device equipped with a map image drawing means that draws a map image including the vehicle position mark and displays it on the screen of the display means, the importance of displaying the road name depending on the positional relationship between the vehicle and the road and the type of road. A vehicle-mounted navigation device characterized in that a setting means for setting is provided, and the map image drawing means draws a road name for a road whose importance is set to a certain level or higher by the setting means. 2. Map data storage means for storing map data, vehicle position detection means for detecting a vehicle position and a vehicle direction, and guide route data storage means for storing guide route data connecting a departure place and a destination. Using the map data read from the map data storage means and the guide route data stored in the guide route data storage means, a map image including the background around the vehicle position, the guide route, and the road name is drawn together with the vehicle position mark on the display means. In a vehicle-mounted navigation device equipped with a map image drawing means for displaying on a screen, the importance of displaying a road name is determined by the positional relationship between the vehicle and the road, the type of road, and whether or not the road matches a part of the guide route. A setting means for setting is provided, and the map image drawing means draws a road name for a road whose importance is set to a certain level or higher by the setting means. In-vehicle navigation device.