JP2000298026A - Car navigation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a car navigation system for displaying directions by displaying geographic information related to each direction seen from the present position of an own vehicle onto a map displayed at present and in a manner to partly hide the map. SOLUTION: Map data near the present position of an own vehicle is read out by a memory medium read device 4 from a map database 3 on the basis of longitude and latitude data of the vehicle by an own vehicle position- processing apparatus 2. Other than map data for plotting a map to a display device 7c, a table of node codes, road names, landmarks, names of directions of intersections and the like are stored in the map database 3. An intersection node which is present on a road in an advance direction of the vehicle and is closes from the present position of the own vehicle is searched for, and name information of directions of an intersection of the searched intersection node is read out from the map database 3. Data is once stored in a main storage memory 5 and, what is converted to display data by a graphic controller 7a is displayed onto a screen of the display device 7c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a car navigation system, and more particularly, to a car navigation system characterized by a direction display method.

[0002]

2. Description of the Related Art Conventional car navigation systems include:
As shown in FIG. 5, usually, a map around the current location of the vehicle is displayed on the screen of the display device, the current position of the vehicle is displayed with an arrow, and the name of the main road is, for example, "Setagaya Street". It was just displaying.

[0003]

However, in such a display method, if the user wants to know where to go when going right, for example, on the first road, the user can scroll the map on the display screen rightward. Had confirmed. Next, when the user wants to see the left side of the current position in this state, the user has to return to the map screen including the original current position and then scroll the map to the left. In addition, when viewing the map at a detailed scale, it is difficult to understand the geographical position of the vehicle, and it is necessary to check the rough map with a low degree of detail.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a car navigation system for performing a direction display.

[0005]

SUMMARY OF THE INVENTION A car navigation system according to the present invention displays geographical information relating to various directions viewed from the current position of a vehicle on a currently displayed map and hides a part of the map. Is displayed.

[0006] A car navigation system according to the present invention displays geographical information relating to each area on a currently displayed map, which information is not present in the currently displayed map. It is.

[0007]

The present invention displays on the display screen of the display device the geographical information present in the traveling direction of the vehicle and viewed from the current position of the vehicle in various directions together with data such as map drawing.

[0008]

FIG. 1 is a block diagram showing an embodiment of a car navigation system for implementing a direction display method according to the present invention. In FIG. 1, 1 is a main controller composed of a microcomputer or the like, 2 is a vehicle position processing device, 3 is a map database formed of a storage medium such as a CD-ROM, 4 is a storage medium reading device, 5 is a main storage memory, Reference numeral 6 denotes an input device, 7 denotes a video processing device, and 8 denotes an audio output device.

The self-vehicle position processing device 2 includes an autonomous navigation sensor 2a, a GPS receiver 2b, and a self-vehicle position calculation device 2c. The self-vehicle related sensor information from the autonomous navigation sensor 2a and the GPS from the GPS receiver 2b are provided. The own vehicle position is calculated by the own vehicle position calculation device 2c based on the current position information of the own vehicle by the satellite radio wave reception. The storage medium reading device 4 reads map data from the map database 3 and supplies the map data to the main controller 1.

The main controller 1 includes unit data of a road network from the storage medium reading device 4 and
The recommended route is calculated based on the current position data of the own vehicle from the own vehicle position processing device 2 and the position data relating to the departure point and the destination of the own vehicle input from the input device 6 and the obtained recommended route data is calculated. It is stored in the main storage memory 5. Further, the main controller 1 reads the recommended route data from the main storage memory 5 and supplies it to the video processing device 7. The video processing device 7 includes a graphic controller 7a, a video RA
M7b and a display device 7c. The graphic controller 7 stores recommended route data in the video RAM 7b.
And the recommended route data read from the video RAM 7b is supplied to the display device 7c and displayed on the display screen.

In the above structure, the direction display method for car navigation according to the present invention displays the geographical information of the current vehicle's current location in the vertical and horizontal directions on the navigation screen while performing normal navigation. In this way, when viewing the first road or a detailed scale map, it is possible to see at a glance where the current vehicle position is geographically located. In the direction display method of the present invention, first, the vehicle position processing device 2 can know the latitude and longitude of the current position of the vehicle. Based on the longitude / latitude data of the vehicle, the storage medium reading device 4 reads map data near the current position of the vehicle from the map database 3. The map database 3 also stores road network information as map-related data in addition to map data for drawing a map on the display device 7c. The road network information includes a table of node records (coordinates and latitudes of a certain road), names of roads, landmarks, names of intersections, and the like. FIG. 4 shows an image diagram of the information of the intersection direction name. In FIG.
The characters in the blocks such as “Kawasaki area” and “Machida area” correspond to the intersection area names, and indicate the names of destinations in the vertical and horizontal directions of the road formed at the intersection.

Therefore, an intersection node existing on the road in the traveling direction of the own vehicle and closest to the current position of the own vehicle is deepened.
The intersection direction name information of the found intersection node is read out from the map database 3 together with the data of the map 4 and the like. The read information and data are temporarily stored in the main storage memory 5 and converted into data that can be displayed by the graphic controller 7a and converted into a video RAM 7b.
And displays it on the display screen of the display device 7c as shown in FIG. In FIG. 3, the arrow indicates the current position of the vehicle,
The characters in the blocks of "Kawasaki area", "Machida area" and "Sangenjaya area" correspond to the intersection area name. By storing the data relating to the intersection direction name in the main memory memory 5 for each direction, for example, if it is not desired to display the direction of the road to which the user has passed (that is, the direction behind the own vehicle), It is not necessary to read the direction name data.

FIG. 4 is a flowchart of the direction display method described above. First, in step S1, the longitude and latitude of the current position of the vehicle are obtained, and then in step S2, a map leaf corresponding to the longitude and latitude is searched. Next, in S3, it is determined whether or not there is map data corresponding to the latitude and longitude. If no, the process proceeds to S4, where error processing is performed, and then the operation is terminated. If the answer to S3 is yes, the process proceeds to S5, and data necessary for map drawing is fetched from the map. Next, at S6, an intersection node closest to the current position of the vehicle is found from the data. Next, in S7, display processing of the intersection direction name of the found intersection node is performed, and the operation ends.

As described above, according to the direction display method of the present invention, it can be realized if there is road node information and intersection direction name information, but as another embodiment, it can be displayed as follows. That is, an intersection (first intersection) closest to the current position is searched for from the current position of the own vehicle based on the node information of the road, and at least one of the intersections within a predetermined distance (for example, 1 km) in the vertical direction from the intersection is searched. Only the intersection (second intersection) may be searched, and the second intersection direction name information may be displayed on the screen of the display device 7c. In this case, the intersection direction name information of the first intersection may be different from the intersection direction name information of the second intersection, and the intersection direction name information of the second intersection farther from the current position of the vehicle may be used. If it is displayed, a farther direction can be displayed.

As described above, according to the present invention, even on the first road, without scrolling the map screen as in the past,
You can see at a glance the geographical position of your vehicle. In addition, even when viewing the map at a detailed scale, the geographical position of the vehicle can be known without changing the scale. Therefore, since the frequency of scrolling decreases and the number of scale changes also decreases,
Reduction in the number of operations leads to safety. Also, when used at the time of an intersection enlargement screen while receiving route guidance, the intersection enlargement screen becomes even easier to understand.

[0016]

According to the present invention, direction name information of each direction from the current position of the vehicle can be displayed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a car navigation system for implementing a direction display method according to the present invention.

FIG. 2 is a diagram showing an intersection area information image diagram for explaining the area display method of the present invention.

FIG. 3 is a diagram showing an example of a display screen for explaining the route search method of the present invention.

FIG. 4 is a flowchart of a direction display method according to the present invention.

FIG. 5 is a diagram showing an example of a conventional display screen.

[Explanation of symbols]

 Reference Signs List 1 main controller 2 own vehicle position processing device 3 map database 4 storage medium reading device 5 main storage memory 6 input device 7 video processing device 8 audio output device 2a autonomous navigation sensor 2b GPS receiver 2c own vehicle position calculating device 7a graphic controller 7b Video RAM 7c display device

Claims (2)

[Claims] 1. A car navigation system wherein geographical information on each area viewed from the current position of a vehicle is displayed on a currently displayed map and a part of the map is hidden. system. 2. A car navigation system characterized in that information that is not present in a currently displayed map and that is geographical information relating to each area is displayed on the currently displayed map.